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61,762
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Evaluation of macrophage electrophoretic mobility (MEM) test as an indicator of cellular immunity in ocular tumours.
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The macrophage electrophoretic mobility (MEM) test of Field and Caspary did not clearly separate patients with ocular neoplastic disease from those with inflammatory disease, although there was some indication of discrimination between choroidal melanoma and ocular inflammation. In our hands the test failed to give a reproducible result for the immunodiagnosis of ocular malignancy. The technique, however, seems to provide some indication of delayed hypersensitivity in experimental inflammatory eye diseases when relatively pure antigens are used.
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61,763
|
Phase partition studies of actinomycin-nucleotide complexes.
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A method is reported for measuring the stoichiometry of complex formation between actinomycin and a series of deoxynucleotides. The amount of bound actinomycin is measured by distribution of the drug between two liquid phases, a buffer phase containing deoxynucleotide and an organic phase in which the nucleotide is insoluble. Using simple statistical mechanical analysis, the equilibrium equations for several models of actinomycin-deoxynucleotide complexes have been derived: actinomycin with one binding site, with two equivalent independent binding sites, and with two sites which must be occupied together. The binding of actinomycin C3 with dpG, dpApG, dpA, and dpGpC has been examined compared with these models. It is found that binding to dpG and dpApG involves two independent binding sites of nearly equal affinity for nucleotides, whereas binding of dpGpC to the two binding sites on actinomycin is a cooperative process. Binding of dpA tp actinomycin is partially cooperative and weaker than binding of dpG. The dimerization constant of actinomycin was also determined by the phase separation technique, and found in agreement with other values, including the results of kinetic measurements reported here.
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61,765
|
Physicochemical analysis of the deoxyribonucleic acid product of murine intracisternal A particle RNA-directed DNA polymerase.
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The nascent DNA transcript of intracisternal A particle RNA-directed DNA polymerase appeared to be covalently linked to an RNA primer. Fidelity of transcription is evident since the DNA transcript hybridized specifically back to 35-70 S RNA of intracisternal A particles but not with heterologous RNAs. This DNA transcript has an approximate molecular weight of 145 000, estimating 350 polynucleotides and base ratios with an excess of dGMP.
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61,766
|
Photophosphorylation as a function of illumination time. I. Effects of permeant cations and permeant anions.
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(1) Very brief periods of illumination do not initiate photophosphorylation in isolated chloroplast lamellae. The time of illumination required before any phosphorylation can be detected is inversely proportional to the light intensity. At very high intensities, phosphorylation is initiated after illumination for about 4 ms. (2) There is no similar delay in the initiation of electron transport. The rate of electron transport is very high at first but declines at about the time the capacity for ATP synthesis develops. When the chloroplasts are uncoupled with gramicidin the high initial rate persists. (3) Various ions which permeate the thylakoid membrane (K+ or Rb+ in the presence of valinomycin, SCN-, I-, or C1O4-) markedly increase the time of illumination required to initiate phosphorylation. Potassium ions in the presence of valinomycin increase the delay to a maximum of about 50 ms whereas thiocyanate ions increase the delay to a maximum of about 25 ms. The effects of K+ with valinomycin and the effect of SCN- are not additive. Permeant ions and combinations of permeant ions have little or no effect on phosphorylation during continuous illumination. (4) The reason for the threshold in the light requirement and the reason for the effect of permeant ions thereon are both obscure. However, it could be argued that the energy for phosphorylation initially resides in an electric potential gradient which is abolished by migration of ions in the field, leaving a more slowly developing proton concentration gradient as the main driving force for phosphorylation during continuous illumination. If so, the threshold in the presence of permeant ions should depend on internal hydrogen ion buffering.
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61,768
|
[Study of the fucose-rich oligosaccharides in the urine of healthy and melituric subjects with A, B and O blood groups].
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The application of adsorption chromatography on charcoal-Celite leads the authors to characterize in normal urines a class of fucose-rich oligosaccharides which possess blood group activities and are related to the phenotypes ABH, Le and secretor. Most of these oligosaccharides have a glucose residue in reducing terminal positions. Excretion of some oligosaccharides increases in the urine of diabetic and lactosuric subjects. In spontaneous or induced galactosurias, the elimination of oligosaccharides with a glucose residue in reducing terminal position decreases while appears a large amount of new oligosaccharides which all possess a galactose residue in reducing terminal position. These results lead to the conclusion that urinary oligosaccharides do not originate from glycosphingolipids, but from transglycosylation on carbohydrates which exist free in the organism: glucose for normal and diabetic subjects, lactose or galactose for lactosuric and galactosuric subjects, respectively.
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61,770
|
[Study of a specific polyoside and a group antigen extracted from Leptospira biflexa patoc, patoc I strain].
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We extracted from L. biflexa patoc a fraction F, reacting in hemagglutination and ring tests with sera prepared against more than ten different serogroups. This fraction contains mainly a polysaccharide (65 per cent), the role of which was clearly demonstrated in the precipitation reaction with homologous antisera, through periodic oxidation; it also contains lipids (20 per cent) and proteins (10 per cent). We isolated from this fraction F, by Biogel column chromatography, 2 distinct antigens, one, F2, carrying the patoc-type specificity, the other, F 1B, a group specificity shared by many leptospira. These antigens differ not only immunogically, but also in their chemical composition. The type-specific antigen F2 contains mainly a polysaccharide composed of arabinose and glucosamine (possibly an immunodominant sugar). As for the group-specific fraction F 1B, its composition is more complex since lipids and proteins are also found with the polysaccharide. This antigen could therefore be a lipoglycoprotein.
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61,769
|
[Structure and immunochemical properties of the urinary oligosaccharides excreted during induced galactosuria].
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Induced galactosuria is characterized by the excretion in urine of large amounts of new oligosaccharides, the structure of which are in connection with blood-group phenotypes ABH, Lewis and Secretor: O group : O-alpha-L fucopyranosyl-(1 leads to 2)-D galactopyranose et O-alpha-L fucopyranosyl-(1 leads to 2)-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D 2-deoxy-2 acetamido-glucopyranosyl-(1 leads to 4)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D-galactopyranose. A group: O-alpha-D-2-deoxy-2 acetamido-galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-D galactopyranose et O-alpha-D-2-deoxy-2 acetamido-galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D-2-deoxy-2 acetamido-glucopyranosyl-(1 leads to)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D galactopyranose. B group : O-alpha-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-D galactopyranose et O-alpha-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D-2-deoxy-2 acetamido-glucopyranosyl-(1 leads to 4)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D-galactopyranose.
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61,771
|
Fluorescence polarization studies of squid giant axons stained with N-methylanilinonaphthalenesulfonates.
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The polarized components of the extrinsic fluorescence of squid giant axons stained with 2,6-MANS or 1,8-MANS were studied. The polarization properties of the fluorescence changes associated with voltage-clamp pulses were found to be very different from those of the static fluorescence, supporting the notion that the optical changes involve highly oriented membrane adsorbed fluorophores. The theoretical expectations according to this hypothesis are discussed in detail. The experimental results are in good agreement with the theory assuming that possible probes reorientations are soley due to the action of the applied electric field upon the probes electric dipole. The quantitative analysis of the data for 2,6-MANS provides a fairly accurate determination of the orientation of the membrane bound 2,6-MANS molecules responsible for the fluorescence changes. Such orientation appears to be independent of the membrane face exposed to staining. The data for 1,8-MANS indicate a very different orientation of this isomer. The results suggest a profitable use of extrinsic fluorophores for studies of the structural organization of nerve membranes.
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61,774
|
Interlibrary loan of audiovisual materials in the health sciences: how a system operates in New Jersey.
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An audiovisual loan program developed by the library of the College of Medicine and Dentistry of New Jersey is described. This program, supported by an NLM grant, has circulated audiovisual software from CMDNJ to libraries since 1974. Project experiences and statistics reflect the great demand for audiovisuals by health science libraries and demonstrate that a borrowing system following the pattern of traditional interlibrary loan can operate effectively and efficiently to serve these needs.
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61,775
|
Results of the Inter-American Investigations of Mortality relating to reproduction.
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Maternal age and parity, according to the findings of the Inter-American Investigation of Mortality in Childhood, have a direct relationship to the health and survival of the infant. Among the results of this broad undertaking are data suggesting that babies born close in succession, especially within large families and as birth order ascends, are at greater risk of dying. Also, the offspring's future is increasingly threatened as the mother's age tends toward the extremes of the childbearing years. Compromise of the mother's health, in turn, was indicated in the earlier Investigation, a study of deaths in adults, which revealed unexpectedly high maternal mortality in the Latin American cities that it covered. Immaturity, or low birthweight, and malnutrition emerged as the two major underlying or associated causes of death in the Latin American projects of the Inter-American Investigation of Mortality in Childhood. Despite the marked variations in the data available from the different areas, there appeared to be some correlation between these two indicators of deficits in growth and development. Mortality due to immaturity was especially high for babies of young mothers, with increases occurring as the birth order rose. Not only are the risks greater for mothers having low-weight babies when they are young (under 20), but they increase even more with the second, third, and fourth products when the birth intervals become shorter. Maternal age, birth order, and birthweight are factors that must be considered in combination in the programming of protective health measures.
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61,782
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Retrograde transport of horseradish peroxidase in transected axons. 3. Entry into injured axons and subsequent localization in perikaryon.
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Horseradish peroxidase (HRP) applied to crushed mouse sciatic nerves diffused through the damaged perineurium into the endoneurium. In the injured area, HRP passed into damaged myelinated and unmyelinated axons forming columns of reaction product, which extended for several millimeters proximally to the lesion. Ultrastructurally, HRP adhered to the inner surface of the axoplasm and to the surfaces of neurotubules and neurofilaments in such columns. At more proximal levels axons contained HRP in vesicular and tubular organelles and, later, nerve cell bodies of the corresponding spinal ganglia showed HRP, accumulation in cytoplasmic vesicles, cup-shaped bodies, multivesicular bodies and tubules of agranular endoplasmic reticulum. Markedly less HRP reached neurons in the spinal ganglia when applied to the nerve 30 or 60 min after the crush. After such time intervals solid HRP containing axons were also less frequently observed. Conceivably, HRP enters crushed axons momentarily after a crush as an injured cell reaction. Subsequently it is incorporated into organelles higher up in the axons, from where retrograde transport to the perikaryon will fellow. This phenomenon of a sudden non-specific influx of exogenous macromolecules into axotomized neurons and their subsequent transport to the perikaryon might be relevant for development of certain biochemical and morphological responses, e.g. lysosomal alterations, of the neuron to an axonal injury.
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61,788
|
Differential central distribution of optic nerve components in the rat.
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The distribution of Fink-Heimer positive degeneration and neurofibrillar proliferation has been examined in the dorsal lateral geniculate nucleus (dLGN) and superior colliculus of albino and pigmented rats following enucleation between post-natal days 12 and 30 and as adults. With survival times of 6 h to 5 days following enucleation, the location of maximum degenerative reaction stained by the Fink-Heimer method changes with increasing survival time in both regions. In the dLGN contralateral to the eye removal the earliest degeneration appears in a lamina occupying the medioventral extent of the nucleus and is rapidly removed; later degeneration fills a central lamina of the nucleus with a patch of degeneration extending to the outer surface of the nucleus at the mediodorsal margin. The latest occurring degeneration fills the outermost lamina and is still obvious when degeneration is largely dispersed from the inner and central laminae; this outer lamina shows an early filamentous degenerative reaction in the adult. The uncrossed optic pathway occupies a portion of the central lamina of the nucleus, and in albino animals it shows a rapid degeneration and dispersion similar to the innermost lamina on the crossed side; in the pigmented animals degeneration of the uncrossed projection starts as early as that of the albino but persists as long as the degeneration of the central lamina on the crossed side. The degeneration time of the sprouted, uncrossed pathway resulting from unilateral enucleation at birth is similar in albino and pigmented rats and resembles in timing the normal uncrossed pathway of pigmented rats. These results suggest that there are at least 3 different fiber populations in the rat optic nerve with different distribution in the dLGN. The uncrossed optic pathway of albino and pigmented rats appears to differ in fiber composition; this may relate to aberrations in mapping of uncrossed projections in the albino.
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61,789
|
Retrograde axoplasmic transport to inactive dopamine beta-hydroxylase in sciatic nerves.
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The transport of dopamine-beta-hydroxylase (DBH) in sciatic nerves was studied both by measuring the accumulated enzyme activity and by examining the accumulated immunologically reactive DBH protein. The pattern of DBH accumulation in the proximal segment was similar either in the activity or in the immunofluorescence. In the distal segment, however, much higher accumulation of immunofluorescence than that of the activity was observed 7 h after ligation. The immunotitration studies indicated that more DBH molecules were accumulated in the distal segment than in the proximal segment 5 h after ligation. The homospecific activity of DBH in the distal segment was about one-fifth of that in the proximal segment. The result suggests that relatively large amounts of inactive enzyme may be transported back to the soma instead of complete degradation in the terminal.
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61,796
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Prenatal diagnosis of genetic disease in Canada: report of a collaborative study.
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A study of 1223 amniocenteses carried out during 1020 pregnancies in 990 women showed that 2nd-trimester amniocentesis at about 16 weeks' gestation is a safe, accurate and reliable procedure for the diagnosis of certain classes of genetic disease when it is monitored by ultrasound, performed by a trained obstetrician and carried out in a major health sciences centre. The percentage of fetal losses (4.7%) and neonatal deaths (0.5%) during the study was not greater than in control samples for women 35 years of age and older. The best results were obtained when needles of gauge 20 or 21 were used. The use of needles of gauge 19 or larger and more than two insertions during a single amniocentesis were associated with a significantly greater frequency of fetal loss than a second or even a third amniocentesis during the same pregnancy. For 39 fetuses (3.8%) a diagnosis of a genetic abnormality was made and 23 male fetuses were found to be potentially hemizygous for an X-linked gene. There were 51 therapeutic abortions as a result of the diagnosis. Sixty-six tests (5.4%) gave an inconclusive result and seven (0.6%) gave an erroneous diagnosis; five of the latter (two false-positives and three false-negatives) resulted from the alpha1-fetoprotein test for neural-tube defects and in two cases the sex was incorrectly determined. The frequency of all chromosome abnormalities was 1:20 when the mother's age was 40 years or more and 1:60 when the mother's age was between 35 and 39 years. When a mother had previously had a child with a chromosome abnormality the risk of recurrence of such an abnormality was 1:100 when the age of the mother was 35 years or more.
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61,798
|
Separation of cellular and viral DNA polymerases by affinity chromatography on polynucleotide-Sepharose.
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Polyguanylate- and poly(2'-O-methyl)uridylate-Sepharose have been prepared for affinity chromatography of DNA polymerases of viral origin (reverse transcriptase). Both cellular DNA polymerases and reverse transcriptase bind to polyguanylate-Sepharose. The cellular polymerases can be eluted from the column between 0.32 and 0.42 M NaCl while reverse transcriptase eluted between 0.56 and 0.78 M NaCl. However, only reverse transcriptase adheres to poly(2'-O-methyl)uridylate-Sepharose and can be eluted at approximately 0.35 M NaCl. The columns were used to partially purify RNA-dependent DNA polymerase from spleens of mice infected with Rauscher leukemia virus. The enzyme preparation is about 1300-fold purified and is inhibited by antiserum prepared against purified reverse transcriptase from Rauscher leukemia virus to the same extent as the virion enzyme.
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61,797
|
New multiple-agent chemotherapy (B-DOPA) for advanced Hodgkin's disease.
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B-DOPA (Bleomycin (B), D-imidazole carboxamide (D), Oncovin (O), Prednisone (P), Adriamycin (A) is a program developed for the treatment of Hodgkin's disease resistant to MOPP therapy. Twenty unselected patients were treated by the following dose schedule: B, 4 mg/m2 days 2 and 5; D, 150 mg/m2 days 1 to 5; O (vincristine), 1.5 mg/m2 days 1 and 5; P, 40 mg/m2 days 1 to 6; A, 60 mg/m2 day 1. Each course, was repeated at 3 to 4 week intervals to maximum adriamycin dose of 450 mg/m2. All patients had received prior MOPP therapy and six had received prior radiotherapy. Fifteen of the 20 patients entered into the study were evaluable for response. There were nine (60%) complete responders and three (20%) partial responders. The median duration of complete remission was 14+ months with six of nine patients remaining in remission to a maximum of 21 months. The median survival of the nonresponders was 3 months. B-DOPA is an effective combination chemotherapy regimen for advanced Hodgkin's disease in patients who have previously received MOPP treatment, including patients who are refractory to MOPP therapy. The B-DOPA program or modifications thereof, may be integrated into primary treatment programs for advanced Hodgkin's disease.
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61,794
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Histological localization of nervous-system antigens in the cerebellum by immunoperoxidase labeling.
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The indirect immunoperoxidase method was used to localize histologically on sagittal sections of mouse cerebellum antigenic determinants detected by the following antisera: anti-NS-2, anti-NS-3, anti-NS-4 rabbit anti-bovine corpus callosum, rabbit anti-mouse brain, rabbit anti-glial fibrillary acidic protein, and rabbit anti-neurofilament protein. Anti-alpha-bungarotoxin serum and normal rabbit serum were used as negative controls. The various sera showed similarities in staining pattern as well as differences. Anti-NS-2 antiserum labeled the somata of interneurons in the molecular layer, granule cell bodies, glial cells in the white matter, and along the surfaces of blood vessels. A similar pattern of staining is produced by the anti-NS-3 antiserum except that glial cells are less prominent in the white matter and the blood vessels are not visible at all. Anti-NS-4 antiserum does not label interneurons but does label glomeruli and, less intensely, granule cell bodies in the granular layer. Rabbit anti-mouse brain antiserum is similar to anti-NS-4 antiserum except that fiber tracts in the white matter are stained more intensely; Rabbit anti-bovine corpus callosum labels only white matter. Antisera to neurofilament ans astrocytes.
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61,799
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Identification and isolation of the major core protein from the oncornavirus-like particle in human milk.
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Subviral cores have been prepared from the oncornavirus-like particle found in human milks with the use of phospholipase C and ether or Sterox SL. The major protein of these cores has a molecular weight of 27,000 daltons, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein is found in the core fractions of reverse transcriptase-positive milks and is absent in negative milks. It is distributed in sucrose gradients only in those fractions containing cores and reverse transcriptase activity. The major core protein of the human milk oncornavirus-like particle is electrophoretically identical to the major core protein of the mouse mammary tumor virus.
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61,800
|
Cell surface changes in HeLa cells as an indication of cell cycle events.
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A HeLa cell line synchronized by double thymidine block and mitotic shake off was shown to have a characteristic surface morphology for each of the different cell cycle stages. Inhibitors of cell multiplication were used to arrest cells in specific cell cycle phases, and these cells had a surface morphology similar to that of synchronized cells in the same phase. The results indicated a close association between the cell surface topography and the cycles of DNA synthesis in the cell nucleus of this HeLa line.
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61,793
|
Nigrothalamic projections in the rat as demonstrated by orthograde and retrograde tracing echniques.
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The nigrothalamic projection of the rat was investigated by means of horseradish peroxidase (HRP) histochemistry and by the autoradiographic tracing technique. The use of these techniques has permitted an extension of previous descriptions by identifying a neuron population in the substantia nigra, pars reticulata (SNR) as the nigrothalamic cells of origin. These calls (20-25 mu) were multipolar and were distributed throughout the SNR. There was a tendency however for more labelled neurons to be observed in the rostrolateral aspects of the nucleus. HRP-labelled neurons comprised roughly one-sixth of SNR neurons of comparable size, ventromedial (VM) thalamic nucleus. In addition, a smaller projection to the ipsilateral parafascicular nucleus was observed. The possible functional sifificance of the nigrothalamic projections is discussed in the light of recent anatomical, physiological and behavioral findings.
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61,801
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In vitro transmission and propagation of the bovine leukemia virus in monolayer cell cultures.
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This study demonstrates that the bovine leukemia virus (BLV) can infect in vitro cells of human, simian, bovine, canine, caprine, ovine, and bat origin. Cultures of these cells, cocultivated with BLV-infected cells or inoculated with cell-free BLV preparations, continuoously showed the presence of cells with the internal BLV antigen as well as BLV-induced syncytia. Virus replication was abundant and increased with passage in bat lung cells and was moderate but constant in fetal canine thymus cells. The amounts of virus released by the simian DBS-FRhL-1 and caprine S-743 cultures were low to moderate during the first 4 to 8 weeks and decreased thereafter. In the infected fetal lamb spleen cell cultures, virus production was low and declined further with passage. Bovine embryonic spleen and human diploid embryonic lung WI-38 cell cultures produced very small amounts of virus only during the first two passages after inoculation despite the fact that they remained infected, as determined by the continuous presence of cell BLV antigen and syncytia. Morphologically and antigenically, the virus particles released by the monolayer cell cultures were indistinguishable from those found in short-term and long-term cultures of BLV-infected bovine lymphoid cells. Repeated electron microscopic examinations and serological tests showed that all the BLV-infected cultures, including those from which the infecting inocula were obtained, were free of the foamy-like bovine syncytial virus, parainfluenza 3 virus, infectious bovine rhinotracheitis virus, bovine viral diarrhea virus, and the maedi-like bovine R-29 virus.
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61,795
|
The role of nerve-growth factor (NGF) in the central nervous system.
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NGF is a protein that stimulates growth and differentiation of sympathetic and sensory components of the peripheral nervous system. The purpose of this review is to examine the evidence that NGF has similar activity in the central nervous system. First, the primary mode of interaction of NGF with the nerve cell will be discussed, and the possibility that such an interaction takes place in the brain will be examined. Recent studies have demonstrated that NGF promotes regenerative sprouting of damaged catecholamine-containing neurons in the brain. The next part of the paper reviews this literature, and other findings that indicate or contraindicate a role of NGF in brain maturation of maintenance. The final part of this paper suggests specific avenues for future research in this area, and presents conclusions regarding the literatureon brain activity of NGF to date.
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61,802
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Alpha-fetoprotein synthesis in tissue culture of human testicular tumors and an examination of experimental yolk sac tumors in the rat.
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The slices of testicular tumors isolated from patients with high serum alpha-fetoprotein (AFP) levels were cultivated in vitro, and the synthesis of some serum proteins, including AFP, was demonstrated. The tumors were produced from yolk sac in rats by fetectomy. The tumors consisted of the various histological structures, such as of teratoma, yolk sac tumor, and very immature tumor. The tumors with yolk sac histology were able to produce AFP. The tumors induced in rats were transplantable, but the well-differentiated histology disappeared after transplantation. The capacity of AFP synthesis in transplanted tumors seemed to be maintained for generations in female rats but not in male rats.
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61,803
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Cell lines derived from teratocarcinomas.
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A variety of cell lines have been isolated in vitro from transplantable teratocarcinomas. Some of them correspond to embryonal carcinoma (EC) cells. They are malignant and represent the stem cells from which all differentiated tissues derive in the tumor or in vitro. EC cells share some biochemical and antigenic properties with multipotential embryonic cells. From one of these EC cell lines, variants have been isolated in vivo and in vitro. Some are of EC type but restricted in their pattern of differentiation; others are altered in their tumorigenicity or in their antigenic characteristics. Another class of such variants corresponds to non-EC types. The most interesting ones correspond to tumoral lines of extra-embryonic tissues. All these cell lines constitute a valuable material for the study of mouse development and differentiation.
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61,804
|
Expression of an oncodevelopmental gene product (alpha-fetoprotein) during fetal development and adult oncogenesis.
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The expression of an "oncodevelopmental" protein, alpha-fetoprotein (AFP), has been systematically studied in rats during normal development and during regeneration of the liver by fetal rat hepatocytes in vitro, in rats bearing transplantable hepatomas, in rats fed chemical carcinogens, and in mice that spontaneously develop hematomas. AFP is a serum protein made normally during fetal and neonatal stages by liver and yolk sac cells. In newborn rats at approximately 4 weeks of age, the production of AFP is abruptly terminated, a process which is closely associated with cessation of liver cell proliferation. In adult rats, AFP production recurs following the reinitiation of hepatic DNA synthesis induced by partial hepatectomy or by the administration of heaptotoxic chemicals. Detailed metabolic and direct labeling studies of fetal rat hepatocytes in vitro also demonstrate a kinetically similar pattern of hepatocyte DNA synthesis and AFP production. In vitro studies utilizing combined autoradiography for DNA-synthesizing cells and immunofluorescence for AFP-containing cells demonstrates that replicating hepatocytes produce AFP, however, available data do not yet permit a distinction between G1 (pre- or postmitotic) and/or G2 production. During growth of an AFP- producing tumor, the serum concentration of AFP may be used as a accurate index of tumor growth, and, if a transplanted tumor is removed, as a marker for metastatic growth of the tumor. Using this model, we have shown that radiation to the lung at the time of surgical removal of a growing tumor in the leg will prevent establishment and growth of pulmonary metastases and that anti-AFP serum treatment may inhibit growth of a transplantable hepatoma that produces AFP. The exposure of rats to chemical hepatocarcinogens results in the appearance of evaluated serum AFP concentration as early as within 1 week of feeding; noncarcinogenic chemical analogs do not cause an elevation. AFP elevation also occurs with low doses of the hepatocarcinogen in the absence of detectable cell injury (by morphological examination of serum enzyme levels) or any other known morphological or biochemical change. This may represent a highly selective derepression of protein synthesis that occurs following the formation of a complex between the metabolites of the carcinogen and specific chromatin loci. Although every rat so far treated with even subcarcinogenic doses of hepatocarcinogens has elevated serum AFP concentrations, many primary carcinogen-induced hepatomas do not produce detectable AFP. Either there is a subsequent change in the preneoplastic AFP-producing cell that occurs prior to irreversible neoplastic alteration, or the hepatocytes originally influenced by the carcinogens to produce AFP are not necessarily the same cells that are the progenitors of the hepatoma produced by more prolonged exposure...
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61,805
|
Cancer, retrodifferentiation, and the myth of Faust.
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The close relationship at the molecular level between cellular differentiation and neoplasia has been evidenced by the discovery in adult individuals of fetospecific antigens and fetal type isozymes associated with many spontaneous and experimentally induced malignant tumors. One question in relation with this finding is whether cancerous tumors develop from the differentiation of a tissue reserve of stem cells or by a process of retrodifferentiation, i.e., the nucleocytoplasmic stepwise reversion of cells toward stationary states with simplified structure and less information content. The question is not merely academic; elucidation of the nature of the target cells from which neoplastic growth emerges has obviously physiopathological and therapeutic implications. This contribution is an analysis of the nature and the mechanism of cellular retrodifferentiation and a discussion of its possible role in regeneration and metaplasia, as well as in neoplastic development. Throughout living systems, retrodifferentiation appears as a common adaptive process for the maintenance of cell integrity against deleterious agents of varied etiology (physical, chemical,and viral). While preserving the entire information encoded on its genome, cells undergoing retrodifferentiation lose morphological and functional complexity by virtue of a process of self-deletion of cytoplasmic structures and the transition to a more juvenile pattern of gene expression. This results in a progressive uniformization of originally distinct cell phenotypes and to a decrease of responsiveness to regulatory signals operational in adult cells. Retrodifferentiation is normally counterbalanced by a process of reontogeny that tends to restore the terminal phenotypes from where the reversion started. This explains why retrodifferentiation remains invariably associated to cell regeneration and tissue repair. There is an ever growing evidence that neoplastic transformation in vivo and in vitro is frequently preceded and/or accompanied by biochemical, morphological, and behavioral transitions characteristic of a cell undergoing retrodifferentiation. Contrary to what occurs in regenerating tissues, the "unbalanced" character of tumor-associated retrodifferentiation seems to be a property linked to cancer. The question arises why a unique mechanism of cell rejuvenation is in physiological conditions (regeneration), followed by a process of reontogeny, while in neoplasia the process remains incomplete or does not occur and leads to the emergence of a population of persistently dividing cells. It is to be hoped that a careful study of retrodifferentiation in physiological and tumoral models will help to distinguish that which in neoplastic development can be relevant to an adaptive cell behavior from that which might eventually be the result of specific or constitutive alterations.
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61,806
|
A general concept for molecular biology of cancer.
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The demonstrations that "fetal" isozymes and other fetal or "oncodevelopmental" antigens are present in tumor cells has led to the general concept that genes normally silent in adult tissues are activated during the neoplastic process. Recent evidence that some chromatin proteins of tumor cells are fetal antigens has suggested that some of the "switches" involved in gene activation for tumor growth may also be fetal or oncodevelopmental. These results have led to current theoretical concept that fetal gene derepressors interact with the genome to produce messenger RNA for the protein products involved for growth, invasiveness, and metastasis. These processes may not be controllable in adult cells because of the lack of inhibitors, which were present during embryonic development but are not produced in adult tissues.
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61,807
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Effects of adriamycin on the reverse transcriptase and the production of murine leukemia virus.
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Adriamycin inhibited the endogenous RNA-, poly (A)-d(T)12-, and calf thymus DNA-catalyzed reaction of reverse transcriptase from AKR mouse murine leukemia virus (AKR-MLV). This inhibition was found at the reaction levels of endogenous RNA-directed and subsequent DNA-directed DNA synthesis. Although adriamycin and actinomycin D significantly reduced the growth of AKR mouse cells (K3b), the treatment with adriamycin could bot inhibit the AKR-MLV production in these cells. Actinomycin D inhibited AKR-MLV production completely in the same experimental condition. In adriamycin-resistant K3b/Am cells, which were isolated by intermittent treatment of K3b cells with adriamycin, persistence of AKR-MLV was demonstrated. K3b/Am cells showed some altered characteristics such as reduced growth rate and tumorigenicity.
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61,808
|
Circulating antibodies in rats bearing grafted colon carcinoma.
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Sera from rats bearing primary or grafted colon carcinoma may contain antibodies that can react with antigenic determinants at the surface of cultivated colon cancer cells. Assays with various target cells and absorption experiments suggest that antigens recognized by circulating antibodies are common to independent lines of cultivated colon cancer cells. They are therefore cross-reacting, tumor-type-specific antigens. They could be embryonic or fetal antigens, because some sera from multiparous animals react with colon cancer cells. However, blocking experiments suggest that these antigens differ from the carcinofetal antigen previously demonstrated on the surface of intestinal cancer cells by xenoantiserum.
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61,809
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Intracellular cations and basophilia in rat liver parenchyma during azo dye carcinogenesis.
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Following formation of hyperplastic nodules, some areas of presumptive preneoplastic liver parenchyma show intense cytoplasmic RNA staining. This hyperbasophilia is not associated with increased ribosome content. Histochemical localization of metallic cations remaining after Carnoy fixation implies an inverse relationship with toluidine blue staining. In liver tissue fixed with potassium pyroantimonate, more inorganic cation precipitation occurs in nucleic of hyperbasophilic foci and hepatomas than within surrounding liver parenchyma. Electron microscopic observations of hyperbasophilic hepatocytes revealed large deposits of cation antimonate within nucleoli and nuclear interchromatin areas and finer deposits in apparent association with cytoplasmic ribosomes. Thus, differences in basophilia may reflect variations in cation levles. Since hyperbasophilic foci show increased thymidine incorporation, cell proliferation may be correlated with histochemically detected alterations of intracellular cations.
|
61,810
|
Intracellular synthesis of alpha-fetoprotein and fibrinogen without secretion by Zajdela rat ascites hepatoma cells.
|
Transplabtable Zajdela rat ascites hepatoma cells, previously considered "nonproducers," synthesize detectable amounts of intracellular alpha-fetoprotein (AFP) and fibrinogen, but fail to secret or release these serum proteins. Evidence for defective secretory mechanisms for serum proteins in these hepatoma cells (a) explains the failure to detect AFP in either the serum or ascitic fluid of rats bearing this hepatoma, (b) indicates that some hepatoma cells should be classified as "nonsecretors," rather than nonproducers of AFP, and (c) suggests that failure to detect AFP in some human and animal hepatomas in vivo and in vitro may also reflect failure of secretion rather than failure of intracellular synthesis.
|
61,811
|
Characterization of embryonic antigens in the plasma of developing chick embryos.
|
Two prominent alpha-fetoproteins are found in chick embryo plasma up to and slightly beyond hatching. Only antisera against chick embryo plasma resolve them. alpha3-fetoprotein is a lipoprotein, the first fetoprotein thus described. It probably functions to transport lipid from the yolk to the embryo. The other fetoprotein (alpha4) is a major glycoprotein. Both are made by the liver and yolk sac. From 9 days onward, albumin is the principal export protein of the liver; at 7 days, when it first appears in the plasma, the yolk sac, but not the liver, makes it. The reverse situation occurs at 9 days. These facts suggest a humoral relationship between the yolk sac and liver. The embryo synthesizes every plasma protein including fetoproteins and "adult" proteins (prealbumin, albumin, and transferrin). No "cold" or unlabeled proteins are seen.
|
61,812
|
Gene activation of molecules with carcinoembryonic antigen determinants in fetal development and in adenocarcinoma of the colon.
|
"Fingerprints" of 0.9% NaCl solution extracts obtained from fetal guts and individual adenocarcinoma of the colon show a randomized pattern of expression of carcinoembryonic antigen (CEA) determinants by CEA radioimmunoassay and isoelectric focusing. All CEA-containing antigens found in a pool of 20 primary adenomas were found at some stage in fetal development. No single CEA-reacting peak was typical of any one period of fetal development. When fetal gut profiles were grouped according to trimester in utero, however, an expanded gene pool was found in the second trimester which correlates well with maximum gastrointestinal growth and differentiation. Isoelectric focusing-CEA radioimmunoassay profiles of individual primary adenomas were similar to but never identical with individual fetal gut profiles. "Fingerprints" of metastatic adenomas of entodermal origin showed quantitative and qualitative increases in molecules with CEA determinants unlike these latter categories. Such data suggest that both integrator and controller gene activities may be lost in metastatic disease. Rather than "phase-specific gene sets" on different chromosomes being activated by various oncogenic modalities, it is more probable that individual chromosomes are involved in oncogenesis. While more data are needed to confirm this idea, it is safe to say that the expression of molecules with CEA determinants need not be caused by either derepressive or reexpressive gene activation. These data point to the individuality of gene expression of molecules with CEA determinants both in fetal development and in early neoplasia. Since CEA-reacting molecules were not found in tumors of ectodermal or mesodermal origin by these methods, such products should be termed carcino-developmental antigens of entodermal or colonic origin.
|
61,813
|
A membrane antigen common to human cancer and fetal brain tissues.
|
Membrane antigens of a cultured human melanoma line, UCLASO-M14, were studied using immune adherence techniques. Allogeneic sera from melanoma patients that were reactive with the M14 but nonreactive with lymphoid cells of the M14 donor were used as antibodies. The antigen responsible for the reaction between M14 and the antibodies was searched for in other cancer, normal, and fetal tissues using antibody absorption techniques. The antigen was found in a variety of different histological types of biopsied and cultured cancer cells as well as in melanomas. The antigen did not exist in biopsied normal tissues, but it appeared in cultured normal skin and muscle. Neither normal lymphocytes nor cultured lymphoid cells showed any antigenicity. The antigen was present in human fetal tissues and was the strongest in fetal brain tissues at 22 weeks of development. Liver, spleen, thymus, and small intestine from the same fetus were negative for antigen.
|
61,815
|
Morphological changes induced by -SH reagents in rod photoreceptor outer segments.
|
Rat retinas were treated in vitro with -SH reagents and "stained" with zinc iodide-osmium tetroxide (ZIO). Dithioerythritol (DTE), an -S-S-reducing agent, increased the electron opaque deposits observed after ZIO staining in the intra- and extradiskal spaces of the rods. N-ethyl-maleimide (nem), an -SH blocking agent, applied directly or after DTE, blocks the ZIO reaction. Furthermore, after treatment with NEM, distorted tubular and vesicular structures are substituted for the stacks of disks. These results strongly suggest that ZIO reacts with -SH groups in rod outer segments. They also indicate that SH-groups play an important role in the structural organization of rod outer segments.
|
61,816
|
New types of islet cells in a cyclostome, Petromyzon marinus L.
|
Four types of acidophilic granular cells, in addition to B-cells, are identified in the islet organ of anadromous specimens of two subspecies of Petromyzon marinus by light and electron microscopy. Three of these acidophils (PI, PII and PIV-cells) occur in both the cranial and hepatic islets while a fourth type (PIII-cell) has only been found in the hepatic islet of some animals. The granules of the PI-cells stain with ponceau de xylidine, give a distinct tryptophan reaction and in ultrastructural examination show large, dense granules. The PII-cells contain unusual crystals and appear to be a non-secretory stage of the PI. The PIII-cells stain deep-red and acid fuchsin. They contain very large, dense granules and some lysosomes. PIV-cells stain selectively with phosphotungstic acid-hematoxylin and ultrastructurally, contain small, more or less dense granules. It appears that PI- and PIV-cells develop directly from B-cells, while the PIII-cells derive from PI-cells. despite their direct or indirect origin from B-cells, the PI-, PIII- and PIV-cells show characteristic features of functionally independent endocrine cells. Petromyzon marinus may be an ideal model for the understanding of phylogenetic and pathological interrelationships between islet and gastrointestinal hormones. It is clear that the interpretation of the islet organ of the cyclostomes, which has been generally considered a source of insulin only, requires a revaluation.
|
61,817
|
Specific binding of anti-myosin and -actin gamma-globulins to the surface of trypsin-dissociated embryonic chick cells.
|
125I-labelled sheep anti-rabbit gamma-globulin antibodies were used to locate rabbit antibodies to smooth- and striated-muscle actomyosins at the surface of trypsin-dissociated embryonic chick cells. Statistical analysis of electron microscope autoradiographs revealed that the plasma membrane of these cells was significantly labelled with both antibodies. Further tests revealed that there were a significantly greater number of antigenic sites present on the cell surface for the gizzard smooth-muscle antibodies than for those against pectoralis straited-muscle actomyosin. It was further shown that both the rate and extent of binding of the 125I-labelled smooth-muscle actomyosin antibodies to the cells were greater than for anti-straited-muscle gamma-globulins. Binding of the former was reduced to a level similar to that of 125I-NIS conjugate by preincubation of the gamma-globulins with smooth-muscle heavy meromyosin, while a simiar reduction was observed when anti-pectoralis actomyosin was treated with actin. It was concluded that actin- and myosin-like proteins must now be considered as integral components of the plasma membrane.
|
61,818
|
Mapping of neurons in the gravity receptor system of the octopus statocyst by iontophoretic cobalt staining.
|
The presence of uni-, bi- and multipolar neurons beneath the hair cell epithelium of the Octopus gravity receptor system has been demonstrated by iontophoretic cobalt staining. Counts give an average number of 1,940 neurons per macula. Whether the hair cells are primary of secondary sensory cells is discussed.
|
61,820
|
Pluripotent teratocarcinoma-thymus somatic cell hybrids.
|
We have produced a series of somatic cell hybrids by fusing pluripotent PCC4aza1 embryonal carcinoma ("teretocarcinoma") cells with thymocytes from young adult mice. When these hybrids form tumors in nu/nu or syngeneic mice, all the tumors contain a range of differentiated tissues, as well as embryonal carcinoma-like tissues. Some of the tumors produce alpha-fetoprotein. These results show that pluripotency in embryonal carcinoma cells need not to be abolished by the introduction of a complete diploid genome from a differentiated cell.
|
61,819
|
Fluorescence-microscopical demonstration of a population of gastro-intestinal nerve fibres with a selective affinity for quinacrine.
|
A population of nerve fibres in the gastro-intestinal tract of mice showing a high affinity for quinacrine was revealed by fluorescence microscopy. Similar results were obtained in rats and guinea pigs. Whole-mounts of sheets of the smooth muscle layer following incubation in 10(-6)-10(-7) M quinacrine for 15-60 min revealed fine fluorescent varicose nerve fibers in the myenteric plexus of Auerbach both around nerve cell bodies and in the interconnecting strands. Many fibers were also present between the strands of the plexus, especially running parallel to the circular muscle layer. Such fibers were not seen in similarly quinacrine-incubated irides. A proportion of the cell bodies in Auerbach's plexus also showed quinacrine accumulation. These cells were apparently smaller neurons, sometimes with fluorescent processes. Intraperitoneal injections of quinacrine failed to demonstrate nerve fibers, but some cell bodies in Auerbach's plexus were positive. Subsequent paraformaldehyde treatment for monoamine visualization showed persistent adrenergic nerve terminals in the intestine and iris. These nerves seemed to be fewer and had a more yellow fluorescence than normally. The identity of the quinacrine-positive fibers is discussed with respect to recent suggestions that "purinergic", substance P, enkephalin, and somatosin-containing nerves, in addition to adrenergic and cholinergic nerves, are present in the gut wall.
|
61,821
|
Cell surface protein decreases microvilli and ruffles on transformed mouse and chick cells.
|
Transformation of cultured fibroblasts usually results in a decrease in a high molecular weight cell surface glycoprotein (LETS protein) and often in increased numbers of surface microvilli and ruffles. We have isolated such a major cell surface glycoprotein from chick embryo fibroblasts; this protein, CSP, is decreased after transformation. Treatment of a mouse tumor cell line (SV1), L929 cells, and transformed chick fibroblasts with CSP results in a decrease in the number of microvilli and marginal ruffles, accompanied by restoration of a more normal morphology.
|
61,824
|
The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. A report of eight patients.
|
Five patients with double outlet right ventricle, ventricular septal defect, pulmonary arterial hypertension and pulmonary vascular obstructive disease and three patients with complete d-transposition of the great arteries, ventricular septal defect, pulonary arterial hypertension and pulmonary vascular obstructive disease underwent an elective Mustard baffle operation. The ventricular septal defect was not closed. A large patent ductus arteriosus was divided in three patients. Seven of the eight patients are alive five to 32 months after surgery; one patient died 11 months after surgery. Cyanosis, dyspnea on exertion, and exercise limitation improved initially in all and has persisted in the survivors. In pre and postoperative hemodynamic studies in four patients, systemic arterial oxygen saturation and effective pulmonary blood flow increased from mean values of 70% to 90% and 1.7/min/m2 to 3.3 L/mon/m2, respectively. Absolute systemic and pulmonary flows, and pressures and resistances, were not significantly altered. Criteria for selection of patients with transposition of the great arteries of double outlet right ventricle who would benefit from a palliative Mustard procedure (Mustard atrial baffle without closure of the ventricular spetal defect) are: 1) severe symptoms; 2) pulmonary arteiral hypertension (75% systemic) with pulmonary vascular obstructive disease; and 3) pulmonary artieral oxygen saturation greater than systemic (ascending aorta) arterial oxygen saturation by approximately 10%.
|
61,825
|
Immunological studies in vitro and in vivo of children with pollenosis given immunotherapy with an aqueous and a glutaraldehyde-treated tyrosine-absorbed grass pollen extract.
|
Ten patients treated with an aqueous Timothy grass pollen extracts and given monthly maintenance doses were compared to ten patients given a glutaraldehyde-treated tyrosine-adsorbed grass pollen extract as five weekly injections pre-seasonally. There were four non-treated controls. Both treated groups showed equivalent increases of total IgE, Timothy-specific IgE, and IgG, but the concentrations of Timothy-specific IgG antibodies were sustained only in the patients receiving maintenance therapy. An increase of IgE and RAST titres during the pollen season were obtained in all three groups. No consistent changes were seen in the results of leucocyte histamine release tests and naso-conjunctival provocation tests from spring to autumn. A Sepharo-protein A technique was used for the estimation of Timothy-specific IgG antibodies. The results obtained with this technique correlated excellently with those of the Farr technique and a double-antibody technique.
|
61,829
|
Factors influencing postoperative vascular patency.
|
In summary, we have briefly examined the pathogenesis of arterial thrombosis, the importance of vessel wall injury and alteration of blood flow in this process, and finally the rationale for use of various agents in an attempt to promote postoperative vascular patency. At present, as in the past, the most important factor toward ensuring patency after arterial reconstruction is a technically perfect operation which allows vigorous inflow and runoff and rapid linear flow (25).
|
61,830
|
Single dose and fractionated palliative irradiation for osseous metastases.
|
A retrospective review of a series of cases of osseous metastases from carcinoma of the female breast treated either with single dose or ten fraction irradiation is reported. Equally reliable palliation was achieved by either method, unaffected by concomitant hormone therapy. The morbidity is assessed and the implications discussed. A prospective study is advocated.
|
61,842
|
Fluroescent characteristics of drumsticks, drumstick-like projections, and other nuclear bodies in human blood cells.
|
The fluorescent properties of drumsticks, drumstick-like appendages, and other nuclear bodies in the polymorphonuclear leukocytes from six human males and females were studied with the aid of the quinacrine-mustard staining technique. Both brightly and weakly fluorescent drumsticks (in females) and drumstick-like bodies (in males) were observed, and they were readily differentiated on the basis of size, shape and, usually, fluorescent intensity. An analysis of the correlation between the extent of nuclear lobulation of the polymorphs and the corresponding fluorescent patterns of the adjoining drumsticks and drumstick-like bodies indicated that a possible change in the state and/or condensation of chromatin in these nuclear bodies might occur with increasing age of the polymorphs. Although the brightly fluorescent regions of the nuclei usually corresponded to the areas darkly stained with Giemsa, much finer patterns of differential staining of drumsticks and other nuclear bodies were obtained only by the fluorescent method.
|
61,843
|
Cell surface antigens. IV. Immunological coorespondence between glycophorin and the a1 human cell surface antigen.
|
A stable human-Chinese hamster ovary cell hybrid has been produced which, in addition to the complement of Chinese hamster ovary (CHO-K1) chromosomes, contains only one human chromosome, No. 11. The human cell-surface antigens whose expression is controlled by human chromosome 11, and are expressed by this hybrid, have been defined as the AL immunogenetic complex. Although one component of this immunogenetic complex (a1) is also expressed by human red blood cells, a second component (a2) is not. Killing of an a1+ hybrid by anti-a1 serum and complement can be completely inhibited by glycophorin, the major glycoprotein component of the human erythrocyte membrane. In the presence of complement, antiserum prepared against glycophorin will kill only those cells which express a1. The anti-a1 killing activity of the anti-glycophorin can be absorbed out only by those cells which express a1. Therefore, it is concluded that the a1 cell-surface antigen has at least one antigenic component in common with glycophorin.
|
61,844
|
Detection of nucleolus organizer regions in chromosomes of human, chimpanzee, gorilla, orangutan and gibbon.
|
Nucleolus organizer regions were detected by the Ag-AS silver method in fixed metaphase chromosomes from human and primates. In the human, silver was deposited in the secondary constriction of a maximum of five pairs of acrocentric chromosomes: 13, 14, 15, 21 and 22. The chimpanzee also had five pairs of acrocentric chromosomes stained, corresponding to human numbers 13, 14, 18, 21 and 22. A gibbon had a single pair of chromosomes with a secondary constriction, which corresponded to the nucleolus organizer region. In each case the Ag-AS method detected the sites which have been shown by in situ hybridization to contain the ribosomal RNA genes. An orangutan had eight pairs of acrocentric chromosomes stained with Ag-AS, probably corresponding to human numbers 13, 14, 15, 18, 21 and 22, plus two others. Two gorillas had silver stain over two pairs of small acrocentric chromosomes and at the telomere of one chromosome 1. The larger gorilla acrocentric chromosomes had no silver stain although they all had secondary constrictions and entered into satellite associations.
|
61,845
|
Effect of Hoechst 33258 on Chinese hamster chromosomes.
|
Cells of the Chinese hamster strain C-125 were treated for different time intervals with H 33258, a bibenzimidazole derivative. The same compound was used to stain fixed cells of the same strain. H 33258 induced in cells in culture specific areas of reduced spiralization on the metaphase chromosomes of some cells. These probably correspond to DNA segments rich in A-T bases interspersed along the chromosomes. Probably H 33258 acts during S period of cell cycle. The banding obtained by staining with H 33258 is similar to that induced by quinacrine dihydrochloride but shows a better resolution.
|
61,848
|
Beyond averaging: the use of discriminant functions to recognize event related potentials elicited by single auditory stimuli.
|
A test of the stepwise discriminant analysis (SWDA) procedure for assessing single-trial event related potentials (ERPs) is presented. Discriminant functions (DFs) were built from a data base composed of single-trial ERPs from sixteen subjects who were presented trains of loud and soft tones. Loud tones occurred randomly on 10% of the trials. Subjects either counted the rare--loud stimuli or solved a hidden-word puzzle. Various DFs at three electrode sites (Fz, Cz and Pz) were obtained to assess the feasibility of performing pairwise discriminations between the various combinations of events which are defined by this procedure. For the pair of events which yielded the most striking differences between their average ERP waveforms it was possible to classify correctly, an average of 84% of the events using information from one electrode site, and 89% of the events if information from multiple electrode sites was used. A "subject-independent" DF was developed from these data and applied to data obtained from seven new subjects. This subject-independent function proved to be sufficiently generalized to classify correctly 81% of the trials. The nature of classification errors by this procedure is discussed.
|
61,849
|
Somatosensory evoked potential in man: far field potentials.
|
Three short latency positive potentials evoked by median nerve stimulation were recorded from the scalp, nose and ear of 11 normal adult subjects in leads where the hand or knee contralateral to the side of stimulation was used as the reference site. The short latencies and positive polarity of these components suggest that they are volume conducted far field potentials. Evidence is presented which suggests that the first potential arises in peripheral nerve fibers. Brain stem and dicencephalic structures are suggested as possible sources for the second and third potentials. The configuration of the response to median nerve stimulation recorded over the cervical spine in ear and hand reference recordings was different. Evidence is presented which suggests that this occurs because the electrode placed on the ear records the far field potentials described in the above paragraph. A far field potential was also recorded in hand--knee leads contralateral to the stimulated median nerve.
|
61,850
|
Activity of neuronal populations of human subcortical structures during sleep.
|
Multi-unit activity of 14 subcortical structures was studied during drowsiness and sleep in patients with depth electrodes implanted in the brain for therapeutic purposes. The mean firing rate of the multi-unit activity was found to decrease during "slow-wave" sleep in each cycle. The multi-unit activity was sharply increased during paradoxical sleep. In successive sleep cycles the mean firing rate somewhat increased from cycle to cycle during slow sleep. The mean firing rate was considerably increased during wakefulness after a sufficiently logn sleep, as compared with the initial background values. Fluctuations of the mean firing rate were characteristic of paradoxical sleep. When studying simultaneously 2 or 3 structures, both uniform or different changes of the neuronal activity were possible. Changes of the firing rate in separate structures may develop a few seconds prior to the "clinical display" of the REM phase. All (or nearly all) the structures, whose activity during sleep is rather independent, are presumed to be able to be a source of the REM phase.
|
61,851
|
Selective regulation of thalamic sensory relay nuclei by nucleus reticularis thalami.
|
Stimulation in the segment of nucleus reticularis thalami adjacent to the lateral geniculate body (RLG), abolished visual evoked potentials for up to 150 msec. Both photic stimulation in the contralateral visual field and electric stimulation in the ipsilateral optic tract elicited primary cortical responses that were markedly reduced or abolished by prior conditioning stimulation in RLG. Stimulation of the segments of nucleus reticularis thalami adjacent to the medial geniculate (RMG) or the ventrobasal complex (RVBC) had the effect of markedly reducing or abolishing unilaterally projected primary evoked responses in the auditory and cutaneous systems, respectively. Only the sensory evoked potentials mediated by the relay nucleus adjacent to the region of R stimulated were affected. The reduction of the cortical evoked potentials was not due to the processes underlying the cortical recovery cycle, because conditioning stimulation on either side of RLG stimulated the primary geniculocortical fibers, but had a minimal or no effect on the visual test evoked response. These results suggest that R functions as a topographically organized inhibitory gate which can regulate the patterns of sensory input from the thalamus to the cortex. The regulatory effects on R by the mesencephalic reticular formation and the mediothalamic-frontocortical system may mediate both generalized and selective control of cortical sensory evoked potentials.
|
61,852
|
Sleep patterns of the laboratory cat.
|
The effects of feeding schedule and external stimuli on sleep patterns were investigated in cats fed to maintain their mean body weight. The ECoG, EOG and EMG wer recorded from 3 male cats fed once daily and under a 12:12 light--dark schedule. The results for 15 working days were compared with those obtained at week-ends and under continuous lighting, fasting, reduced food intake or overfeeding. Feeding was also divided into 3 meals per day. Despite some differences in their responsiveness. All cats exhibited the usual values for the critical variables of SWS: diurnal placement, intermittency and total amount. A low percentage of PS per 24 h was recorded. This was related both to the restricted amount of food eaten and to the feeding schedule. Reduced external stimuli at week-ends resulted in concentration of sleep during daytime, whereas sleep was reduced during continuous lighting in conjunction with an increased percentage of drowsinessess. The most marked effect of fasting (pig fat) was fragmentation of sleep episodes. Divided meals and an increased food intake both increased the total sleep duration. It is suggested that the restricted amount of food and relatively enriched environment used, accompanied by a reduced sleep duration, may be comparable to that seen in free animals. Sleep patterns in the cat are very responsive to light--dark schedule, reduced external stimuli and fasting.
|
61,853
|
Electroencephalographic synchronization induced by stimulation of small intestine and splanchnic nerve in cats.
|
1. In freely moving cats, the cortical desynchronization elicited by painless rhythmic distension, or by low voltage electric stimulation, of the small intestine in drowsiness and slow wave sleep is extinguished following a few repetitions. After extinction of the arousal reaction, similar intestinal stimulation was systematically followed by the appearance of synchronized activity, or an increase of spontaneous synchronization, in the explored cortical areas (parieto-occipital). 2. Intestinal or splanchnic stimulation at an intensity below threshold for cortical desynchronization immediately induced synchronized activity without any need of previous repetitions of stimulation. 3. Stimuli which were followed by synchronization excited only the large (Abeta) splanchnic afferents. The authors conclude that intestinal receptors may be one of the sources of synchronizing influence which can contribute to the regulation of the sleep-wakefulness cycle and that the large splanchnic afferents may play a role in the induction of synchronization.
|
61,854
|
Conditioned EEG desynchronization and seizure occurrence in patients.
|
Five patients with seizures poorly controlled by standard anticonvulsant medication, underwent EEG operant conditioning. The operant paradigm reinforced the production of low voltage fast activity while decreasing frequencies below 10 c/sec. Seizure frequency decreased in 2 patients, seizure severity was attenuated in 2 others, and one patient who was only given reinforecement for scalp EMG suppression whowed no change in seizure parameters. Pseudoconditioning and control periods ruled out placebo effects. A rationale for this phenomenon is proposed.
|
61,856
|
Occurrence of the H reflex and the F wave in the rat.
|
In adult rats the tibial nerve was stimulated at the ankle and the evoked EMG of the foot muscles was recorded. A low threshold reflex discharge was elicited that was subsequently depressed by stronger stimuli eliciting the direct (M) wave. This discharge was abolished by cutting the dorsal roots (except for 1-3% postulated to be due to recurrent discharge). It had a central latency of about 2 msec, was depressed by stimulation rates above 0.3/sec and showed posttetanic depression, all of which are also properties of the rats's monosynaptic reflex. By analogy it is assumed to be an H reflex.
|
61,855
|
Automatic recognition and quantification of interictal epileptic activity in the human scalp EEG.
|
An attempt was made at using a small computer to recognize and quantify interictal epileptic activity (spikes and sharp waves) in the human scalp EEG. To perform the automatic recognition, the EEG of each channel is broken down into half-waves. A half-wave is characterized by its duration and its amplitude relative to the background activity. A wave is characterized by the durations and amplitudes of its two component half-waves, by the second derivative at its apex measured relative to the background activity, and by the duration and amplitude of the following half-wave. Particular combinations of these parameters were found to characterize spikes and sharp waves and are used for their recognition and quantification. Specific methods are used for the rejection of spike-like or sharp wave-like wave forms such as eye blinks, muscle potentials and sharp alpha activity and were found to perform with a high level of reliability. Interchannel relationships are thoroughly examined to determine areas of maximal epileptogenicity. Sixteen channels can be analyzed in real time. Results are presented in a simple picture containing localizing and quantitative information. Specific questions regarding the time relationships of spikes in different channels can be asked interactively by the user. The system is of potential use in clinical electroencephalography.
|
61,857
|
[Steroid metabolism in primates. XVIII. Return to higher levels of 17-ketosteroid excretion in urine after ending a long-term treatment with mestranol/chlormadinone acetate in the baboon].
|
6 weeks after terminating a long-time application of the ovulation inhibitor Ovosiston (mestranol/chlormadinone acetate) in female baboons, excretion of 17-ketosteroids in urine is still decreased. 6 months after ceasing the preparation, urinary 17-ketosteroid excretion resembles that of the control group.
|
61,859
|
Torpedo marmorata acetylcholinesterase; a comparison with the Electrophorus electricus enzyme. Molecular forms, subunits, electron microscopy, immunological relationship.
|
Electron microscopy, sequential degradation by hydrolytic enzymes and the physical-chemical properties of the molecular forms of Torpedo acetylcholinesterase indicate that these molecules are structurally related to each other in the same way as the molecular forms of Electrophorus acetylcholinesterase: all are derived from a complex structure in which three tetrameric groups of subunits are associated with a rod-like 'tail'. In aged preparations the catalytic subunits are split into fragments in a manner similar to those of Electrophorus acetylcholinesterase. Immunological cross-reaction between both enzymes demonstrates the occurrence of common antigenic sites. The enzymes from the two sources, however, are different in their molecular weights and susceptibility to hydrolytic enzymes. Also, Torpedo acetylcholinesterase does not precipitate with either isologous or heterologous antibodies.
|
61,860
|
Identification of the triploid genome by the C-banding method.
|
We report on cytogenetic studies of a malformed fetus, whose clinical symptoms indicated the diagnosis of triploidy. This was confirmed by chromosome analysis of peripheral lymphocytes of cord blood. Using the C-banding method it was possible to identify the origin of the extra haploid set: marker chromosomes indicate, that nonreduction of the first meiotic division in the father's spermiogenesis most probably leads to triploidy. However, in our case fertilization of the zygote by two sperms cannot be excluded.
|
61,862
|
Pharmacokinetic analysis of the interaction between dicoumarol and tolbutamide in man.
|
The effect of repeated administration of tolbutamide on the elimination and anticoagulant action of a single oral dose of dicoumarol 600 mg was studied in four healthy male subjects using a crossover design. In all subjects the plasma concentration of dicoumarol in the postabsorptive phase was lower during concomitant tolbutamide treatment. However, the subjects differed with respect to the elimination kinetics of dicoumarol and the effect of tolbutamide on some of the measured pharmacokinetic paramaters. In two subjects dicoumarol was eliminated by apparent first-order kinetics. Tolbutamide led to a pronounced increase in the elimination rate and a shift in the plasma concentration-response relationship towards a lower concentration of dicoumarol. The total hypoprothrombinaemic effect per dose of dicoumarol was not affected. The decline in the dicoumarol concentration in plasma in the other two subjects was concentration-dependent. Apparent first-order kinetics were observed only at plasma concentrations below 10 mg/L. Tolbutamide treatment did not markedly affect the slope of the terminal portion of the plasma concentration vs. time curve, but diminished the area under the total curve. The plasma concentration-response relationship of dicoumarol was not affected by tolbutamide, but there was a small decrease in the area under the anticoagulant effect vs. time curve. The plateau level of tolbutamide in plasma increased considerable in all subjects after administration of one dose of dicoumarol. Thus, simultaneous administration of tolbutamide and dicoumarol to man often causes no changes in the anticoagulant activity of dicoumarol, but this is due not to lack of interaction of the drugs but to the complexity of their interactions, involving processes that may counteract each other.
|
61,863
|
Denaturing effect of x-irradiation on deoxyribonucleic acid aqueous solutions: An immunochemical study.
|
The denaturation of calf thymus DNA aqueous solutions following x-ray radiation (x-DNA) has been investigated with the help of a rabbit antidenatured DNA antiserum. These antibodies were shown to recognize exclusively single-stranded DNA determinants on DNA molecule in double immunodiffusion analysis. By means of this method it was possible to demonstrate that increasing numbers of single-stranded DNA determinants were formed in DNA solutions exposed to increasing doses of radiation. The rabbit serum appeared to be a highly sensitive reagent (0.5 mug/ml of single-stranded DNA) capable of detecting DNA denaturation when low ionizing doses were used and when only minor changes in DNA physico-chemical parameters were measurable. Antigenic comparison between x-DNA and heat-denatured DNA demonstrated that antigenic determinants are shared by the two molecules. The possible application of immunochemical methods to the study of nucleic acid denaturation by different physical and chemical agents is discussed.
|
61,864
|
Rabbit alpha-fetoprotein: normal levels and breakage tolerance with haptenated homologous alpha-fetoprotein.
|
Nanogram quantities of alpha-fetoprotein (AFP), a tumor associated fetal protein, were found in the serum of normal adult rabbits by radioimmunoassay. This AFP was isolated and shown to be immunologically identical to fetal AFP by immunodiffusion. Immunizations of rabbits with unmodified to desialylated AFP in complete Freund's adjuvant did not cause antibody formation, indicating the existence of tolerance against homologous AFP. The tolerance could be terminated by immunizing with hapten-coupled AFP, which resulted in production of rabbit antibodies reacting with unmodified rabbit AFP.
|
61,865
|
Quantitative analysis of an idiotypic determinant of light chains of normal human IgG and IgM.
|
Normal light chains of human IgG and IgM were analyzed for the presence of the idiotypic determinant of light chains identified by anti-"a". A quantitative evaluation indicated that this marker of the variable region was present in light chains obtained from IgG and IgM; however, light chains reacting with anti-"a" were preferentially associated with IgG molecules.
|
61,867
|
Antigen binding and idiotypic properties of reconstituted immunoglobulins G derived from homogeneous rabbit anti-pneumococcal antibodies.
|
Recombinations and hybridizations of H and L-chains derived from several homogeneous rabbit antibodies to type 3 pneumococcal polysaccharide (SIII) were carried out. All reconstitution experiments performed gave rise to genuine IgG molecules. Antigen-binding studies and affinity measurements for a hexasaccharide ligand derived from SIII were made. In addition, heterologous antiidiotypic serum raised against one rabbit anti-SIII antibody was used to measure the reconstitution of idiotypic determinants in hybrid immunoglobulin molecules. The results show that full recovery of the antigen-binding properties was obtained only when chains derived from the same antibody molecules were reassociated. Similarly, the complete regain of idiotypic determinants (studied in one antibody system) could only be demonstrated in the homologous recombinants. The pairing of an H-chain with several heterologous L-chains, which differed in 6-11 positions in the 3 hypervariable sections, led to the formation of hybrid IgG molecules which had an affinity at least 100-fold lower than that of the parent anti-body molecule and a number of hapten-binding sites which did not exceed 0.30.
|
61,869
|
Analysis in deoxycholate of three antigenic specificities associated with the rat Thy-1 molecule.
|
Three antigens similar in tissue distribution can be identified on rat thymocytes; the Thy-1.1 antigen, a rat specific xenoantigen, and a rat-mouse cross-reacting xenoantigen. To determine if these three antigens were on the same molecule their behavior in detergent-solubilized extracts from thymocytes was studied. Membrane fragments containing Thy-1.1 activity were prepared by a rapid method involving the use of Tween-40 detergent, and were solubilized in deoxycholate. The 150 000 x g supernatant from this extract contained approximately 50% of the original Thy-1.1 and xenoantigen activity. The supernatant was chromatographed on Sephadex G-200, and subjected to zone sedimentation on sucrose gradients in H2O and 2H2O to determine the hydrodynamic properties of the antigens. The three antigens migrated in identical fashion in all cases, and behaved as a molecule of 28 000 daltons molecular weight. When the antigenically active fraction, recovered after chromatography on Sephadex G-200, was passed through an immunoabsorbent consisting of rabbit antibody to one of the xenoantigens, all three antigens were equally depleted compared with passage through a control column. The results of these experiments suggested that Thy-1.1 antigen and the two xenoantigens were closely associated and most probably all on the Thy-1 molecule.
|
61,868
|
Antigens on mouse and rat lymphocytes recognized by rabbit antiserum against rat brain: the quantitative analysis of a xenogeneic antiserum.
|
Quantitative assays for measuring the binding of xenogeneic antiserum to dispersed cell suspensions are described. Cells were incubated with unlabeled xenogeneic antiserum and the antibody bound measured indirectly by a second binding step with 125I-labeled anti-immunoglobulin antibody. This indirect radioactive binding assay was calibrated by measuring, with a radioimmunoassay, the true amount of antibody bound in the first step. With these methods one can measure the strength of antisera, quantitate the number of antigenic sites, and partially differentiate determinants being recognized on cell surfaces. The binding of rabbit anti-rat brain antiserum to rat and mouse lymphocytes was analyzed in detail. After absorption of the antiserum with rat liver, the antibody remaining recognized lymphocyte antigens that were distributed among various rat and mouse tissues in quantities identical to Thy-1.1 antigen. Thus, at saturation, 670 000 Ig molecules from liver-absorbed rabbit antiserum were bound per rat thymocyte, and the antiserum bound to 90%, 21%, 4% and 2% of rat thymocytes, spleen, lymph node and thoracic duct lymphocytes, respectively. With mouse tissues, 90% 24% and 50% of thymocytes, spleen and lymph node cells, respectively, were labeled. In rat brain the concentration of xenoantigen increased with age, while in thymocytes the full adult amount was present at birth. Three antigenic determinants could be defined with the liver absorbed rabbit antiserum: the Thy-1.1 antigen, a rat specific antigen and an antigen cross-reacting between rat and mouse tissues. All 3 may be on the Thy-1 molecule. The anti-brain antiserum contained about 0.05 mg/ml of antibody specific to these xenoantigens.
|
61,870
|
Fine specificity of the H-2 linked immune response gene for the gallinaceous lysozymes.
|
An immune response (Ir) gene is described which controls the ability of mice to respond to seven very closely related gallinaceous egg white lysozymes (GEL). This Ir-GEL gene locus is linked to the major histocompatibility locus of the mouse and operates at the level of the T cell. Responsiveness to the nonimmunogenic prototype hen egg white lysozyme (HEL) is dominant and is unrelated to age or sex of the animals, or to dose of protein administered. Ninety percent of C57BL/6 mice are absolute nonresponders to the nonimmunogenic lysozymes in complete Freund's adjuvant. The remaining mice exhibit severely restricted responses, with different anti-HEL clonotypes appearing in individual mice. The fine specificity of the Ir-GEL locus is evident in the discrimination of as few as two amino acid differences in a single region of the lysozyme molecule. This very precise distinction determines whether there will, or will not, be any response to the multideterminant molecule.
|
61,873
|
Induction of allergic encephalomyelitis using hydrosoluble mycobacterial fractions.
|
Experimental allergic encephalomyelitis has been induced in guinea pigs employing bovine myelin basic protein as the antigen and a hydrosoluble tetrasaccharide-heptapeptide from delipidated cells of the human mycobacterial strain H37Ra as adjuvant. The maximum response was observed using 33 mug of antigen and 12.5 mug of adjuvant per animal.
|
61,871
|
Independent expression of the two HL-A antigen polypeptide chains.
|
It is now well established that beta2-microglobulin constitutes one of the two HL-A antigen subunits. In this study support was obtained for the previous notion that the human lymphoma Daudi does not produce beta2-microglobulin (beta2m). Papain-solubilized as well as Nonidet P-40-solubilized Daudi HL-A antigens do not contain any beta2m or any detectable structural analogue of this protein. The chemical and physico-chemical characteristics of highly purified HL-A antigens derived from Daudi cells are indistinguishable from those of the HL-A antigen-carrying polypeptide chain isolated from the P3HRIK cell line. Like P3HRIK-derived HL-A antigens, the HL-A antigens derived from Daudi cells are composed of two identical heavy, alloantigenic polypeptide chains with a molecular weight of about 50 000 each, which are held together by disulfide bridge(s). The HL-A antigens of P3HRIK cells contain, in contrast to Daudi HL-A antigens, two molecules of beta2m. Although no evidence was obtained suggesting any beta2m synthesis in Daudi cells it was apparent that these cells express the HL-A alloantigenic polypeptide chain in amounts similar to those of other cell lines which produce beta2m. The present data suggest [1] that beta2m and the alloantigenic HL-A polypeptide chain are under separate genetic regulation [2], that the cell surface integration of the HL-A antigen-carrying polypeptide chain is independent of the presence of beta2m and [3] that beta2m does not constitute a membrane component absolutely necessary to the integrity of the cell membrane.
|
61,872
|
Immune response to phosphorylcholine. I. Characterization of the epitope-specific antibody.
|
The antibodies to phosphorylcholine induced in BALB/c mice were isolated and studied with a variety of biochemical and immunochemical methods. Analysis of the idiotype and the hapten-binding specificities showed no differences to the phosphorylcholine-binding myeloma protein TEPC 15, indicating a high degree of homogeneity. However, disc electrophoresis, isoelectric focusing and amino acid composition data indicated large differences in the structure of anti-phosphorylcholine antibody and TEPC 15. By these criteria the anti-phosphorylcholine antibodies from BALB/c mice are of oligoclonal origin.
|
61,874
|
Idiotype suppression. II. Amplification of a suppressor T cell with anti-idiotypic activity.
|
Guinea pig IgG2 anti-idiotypic antibody (aId2) against the strain A/J antibody A5A has a suppressive effect on the expression of the A5A idiotype in adult A/J mice immunized with Group A streptococci. High doses of aId2 cause an immediate but transient suppression, whereas low doses of aId2 result in a delayed but chronic suppression which lasted for more than 1 year without any indication of recovery. Chronic suppression is transferred by as few as 10(5) spleen cells, but an interval of 6 weeks after transfer is required for completion of suppression. The suppressive capacity of aId2-induced suppressor cells was virtually inexhaustable in 4 consecutive transfers spaced at 3 month intervals. The suppressor cell is a T cell which adheres to histamine-rabbit serum albumin-Sepharose 2B columns.
|
61,875
|
Correlation of "sneaking through" of tumor cells with specific immunological impairment of the host.
|
The preferential take of tumors after small-size inocula of transplantable tumor cells has been described for many systems. The phenomenon has been named "sneaking through" or "dilution escape". Using a BALB/c mastocytoma, we have analyzed the immunological parameters accompanying sneaking through that can be observed upon injection of 10(1) to 10(3) living cells. Mice can also be conditioned by injection of low, subimmunogenic numbers of irradiated cells to show increased tumor incidences upon injection of living cells in doses two orders of magnitude above the sneaking through dose. The general immune reactivity of the animals is not impaired under these conditions. However, determinant-specific unresponsiveness is found which can be transferred by spleen cells and therefore seems to be actively maintained. It is concluded that sneaking through of tumor cells is the result of specific immunological impairment of the host's immune system by subimmunogenic small-size inocula of tumor cells.
|
61,876
|
Sharing of idiotypic specificities between different antibody populations from an individual rabbit.
|
Rabbits hyperimmunized with tobacco mosaic virus synthesize very heterogeneous antibodies. Despite this, specific anti-idiotypic sera recognizing a large part (70%) of these antibodies can be raised in rabbits matched for allotypic specificities a1, a2, a3, b4, b5, b6, c7, and b9. Different rabbits synthesize antibodies with different idiotypic specificities. However, in the serum of a single rabbit antibody fractions of different isoelectric pH share some idiotypic specificities. The results show that, at least in certain cases, antibodies against one antigen are not simply a random collection of immunoglobulin which happen to fit with this antigen, but that some definite relationship exists between the products of different clones which have been activated by antigen. These findings are discussed in the light of network concepts of the immune system.
|
61,877
|
Deletion of hinge region of human myeloma IgG1 molecule (protein LEC) associated with nonexpression of G1m (3) and Km (1, 2) allotypes. A possible genetic explanation at the DNA level.
|
In this paper we report the structural basis for the nonexpression of G1m(3) and Km (1,2) allotypes in an IgG1 (kappa) human myeloma protein (protein LEC). Heavy and light chains spontaneously dissociate in sodium dodecyl sulfate polyacrylamide gels. Light chains appear to be covalently S-S bonded. Analysis of cysteine-containing peptides shows that the heavy chain of the IgG protein LEC has a deletion of residues 216-230, thus encompassing the entire hinge region. An arginine residue, characteristic of the G1m(3) marker is present at position 214. An alanine at position 153 and a leucine at position 191 of the light chain, characteristic of the Km (1, 2) allotypes, are present. It is likely that the double Km and Gm lack of expression is the result of the deletion. The genetic implications of the sequence of this protein are discussed.
|
61,878
|
Immunological properties of murine thymus-dependent lymphocyte surface glycoproteins.
|
The immunological properties of two murine thymus-dependent (T) lymphocyte surface glycoproteins, T200 and T25, were investigated. T200 is a lymphocyte-specific antigen with a high degree of species specificity. It shares antigenic determinants with molecules present on thymus-independent (B) lymphocytes. T25 has antigenic determinants which cross-react with antigens on mouse brain, rat thymocytes and rat brain. An antiserum against a purified rat brain glycoprotein which carries Thy-1.1 reacts with T25. Absorption of this antiserum with BALB/c thymocytes or brain homogenate produces a Thy-1.1 specific serum which reacts with T25 from AKR/J thymocytes but not with T25 from AKR/Cum thymocytes. These results confirm that T25 is the molecule on the surface of mouse T cells which carries the Thy-1 antigen. T25 also carries antigenic determinants, recognized by anti-thymocyte serum (ATS), which were found on secondary mouse embryo fibroblasts and untransformed fibroblast cell lines but which were not detected on fibroblast cell lines transformed with murine sarcoma virus (MSV) or with Simian virus 40 (SV40).
|
61,879
|
Expression of Ia determinants on immunocompetent cells.
|
The expression of Ia (immune response region-associated) antigens on the surface of lymphocyte subpopulations with defined immunological function has been investigated by negative selection of subpopulations with anti-Ia sera and complement. Ia determinants were found on both unprimed (IgM) and on primed (IgG) antibody-forming precursor cells. No Ia antigens were detected on the surface of helper T cells. In contrast, suppressor T cells were sensitive to treatment with anti-Ia sera and complement demonstrating the presence of Ia determinants on this T cell subpopulation.
|
61,880
|
Stimulation and suppression of rat mast cell functions by alloantibodies.
|
The stimulatory as well as the inhibitory capacity of alloantisera has been investigated with respect to rat mast cell functions. Alloantibody against alloantigens coded for by the major histocompatibility (H-1) gene region promoted histamine release from purified LEW mast cells. This process was found to be complement-independent but demonstrated an absolute requirement for calcium. Pretreatment of mast cells with anti-H-1 antisera in the absence of calcium markedly suppressed the IgE-dependent histamine release challenged either by antigen or by anti-IgE antibody. The alloantisera, however, did not interfere with the ability of compound 48/80-associated histamine liberation. Additionally, antibodies specific for H-1 antigens were highly effective in inhibiting the binding of IgE to the mast cell surface. Alloantisera absorbed with erythrocytes lost their capacity to block mast cell functions. Based on these data the possible ralationship between H-1 alloantigens and the IgE receptor on the mast cell surface is discussed.
|
61,881
|
Production of xenogeneic and allogeneic antisera specific for mouse thymus-derived lymphocytes.
|
Xeongeneic and allogeneic antisera were raised in rabbits and mice using purified mouse T cell-specific antigens. These antisera were shown to be reactive in complement and antibody-dependent cell-mediated cytotoxicity tests as well as in immunofluorescence, with 30% of mouse spleen cells, 80% of lymph node cells and 100% of thymocytes or various T lymphoblastoid cell lines labeled. No reaction could be detected with bone marrow cells or non-T cell lines. Both types of reagents bound to the same spleen lymphocyte subpopulations and competed for the same antigenic sites as anti-Thy-1.2 alloantiserum. These antisera raised with small amounts of immunogens did not require any absorption to be rendered specific for mouse T cells.
|
61,887
|
Transport of RNA along the optic pathway of the chick: an autoradiographic study.
|
Autoradiograms of the optic tectum were made 8 days after monocular injection of 3H-uridine in 3 day-old chicks. Electron microscopic analysis of grain density over morphological structures in various layers of the optic tectum contralateral to the injected eye, was carried out. This revealed that the highest concentration of labeled RNA was within the axons of the more superficial layers of the tectum. A lesser density of grains was observed over glial cells, neuronal perikarya and dendrites. In addition, the bulk of the total grains counted were over axons. In lower tectal layers, radioactivity was predominantly over unmyelinated axons and glial elements. High molecular weight RNA appears to be transported within the axons of the optic nerve toward their terminations which are largely in the outer layer of the optic tract.
|
61,890
|
Occurance of aldehyde-fuchsin and performic acid-victoria blue positive granules in the ovarian pedicle of Dysdercus koenigii F. (Pyrrhocridae: Heteroptera).
|
A cycle of activity of aldehyde-fuchsin and performic acid-Victoria blue positive granules was observed in the ovarian pedicle of Dysdercus koenigii during the first ovipositional cycle. The quantitative variation of these granules in the pedicle can also be correlated directly with the increase or decrease of the neurosecretory material in the A-type cells of the pars intercerebralis medialis region of the protocerebrum of the brian.
|
61,891
|
Effect of bilateral adrenalectomy and parenteral betamethasone on gastric mucosal mast cell population in albino rats.
|
The histamine-laden mast cells of gastric mucosa in albino rats are shown to degranulate on administration of Betamethasone, but they increase in number in adrenalectomized rats. It is concluded that Betamethasone, and also adrenal glucocorticoids increase gastric secretion by liberating histamine from mast cells and histamine in turn acts on the gastric glands.
|
61,892
|
Spread of cobalt from a cortical epileptic lesion induced by a cobalt-gelatine implant into the frontal cortes of the rat.
|
The spread of cobalt ions from cobalt induced epileptic foci in rats has been investigated. Atomic absorption spectrophotometry and heavy-metal histochemistry reveal cobalt ions spread very widely from the focus. Biochemical and physiological consequences for this model of epilepsy are discussed.
|
61,893
|
Release of immuno-reactive and biologically active LH from fetal mouse pituitary in response to synthetic gonadotropin releasing factor (LRF).
|
In an incubation system, LRF stimulated significantly the release of LH from 18-day-old mouse fetal pituitary. This LRF-induced LH release, measured by RIA in the incubation medium was able to increase the testosterone production by age-matched fetal testes. This data suggests that the hypothalamo-hypophyseal-testicular axis is functional at the end of mouse prenatal life.
|
61,894
|
Effects of injury on the concentration of alpha1-macroglobulin and alpha2-macroglobulin in the plasmas of male and remale rats.
|
The effects of injury on the concentration of alpha1-macroglobulin and alpha2-macroglobulin in the plasmas of male and remale rats has been investigates. At 5 days after injury to the male rats the alpha1-macroglobulin concentration increased to 131% of its preinjury value. The alpha2-macroglobulin concentration increased more rapidly to a maximum of 86 times its initial value. In the female rats alpha2-macroglobulin increased only slightly and alpha1-macroglobulin not at all.
|
61,895
|
Experimental allergic encephalomyelitis: role of fibrin deposition in immunopathogenesis of inflammation in rats.
|
The immunopathogenesis of experimental allergic encephalomyelitis (EAE) is reviewed with special focus on the role of central nervous system fibrin deposition in the inflammatory cascade characterizing this autoimmune disease. Among rats sensitized to whole spinal cord or myelin basic protein of either guinea pig or bovine origin, there is a striking degree of concordance of perivascular fibrin deposits and occurrence of clinical paralytic signs. Neither paralytic signs nor fibrin deposition are temporally related to development of perivascular cellular infiltrates. Rats sensitized to neuroantigen and treated with ancrod, a polypeptide derived from the venom of Agkistrodon rhodostoma, develop profound hypofibrinogenemia, have a marked inhibition of fibrin deposition, and often exhibit no paralytic signs whatsoever. In contrast, cellular infiltrates are not demonstrably influenced by ancrod treatment. Activation of the clotting cascade at loci of developing immune injury of nervous tissue appears to result from and lead to increasing neurovascular permeability and accumulation of edema fluid. Distention of the extracellular space in central and peripheral nervous system tissues by edema fluid appears to be directly responsible for clinical abnormalities characterizing EAE in rats. Cellular infiltrates, on the other hand, appear to be an independent immune response to neuroantigenic sensitization.
|
61,899
|
[Complete transposition of the great arteries: hypertensiol pulmonary vascular disease in the first six months of life (author's transl)].
|
Lung specimens of 27 patients under six months of age with complete transposition of the great arteries (TGA), obtained at autopsy, were studied histologically. No evidence of hypertensive pulmonary vascular disease was found in patients under four months of age (23 patients), while obstructive intimal proliferations were seen in 2 patients, aged four and five months, with TGA and VSD. Since pulmonary vascular lesions in transposition with VSD appear early in infancy, timely palliative procedures, such as banding of the pulmonary artery, are strongly indicated when the radical corrective operation is to be postponed.
|
61,901
|
Role of the spleen in hepatic disorders--experimental study from the viewpoint of antigen antibody reaction.
|
Experimental studies, using albino rabbits, showed that following the sensitization with histamine and homologous liver antigen conspicuous liver injury, closely resembling chronic active hepatitis, which progressed into liver cirrhosis with pseudolobulus formation, could be induced. The splenic weight, obtained after the administration of several hepato-toxic substances, had intimate relation with serum gammaglobulin levels. Furthermore, in a group in which splenectomy was performed after the development of hypergammaglobulinemia, serum gammaglobulin resulted in a rebound increase in comparison with extremely low level of serum gammaglobulin in a group in which splenectomized prior to sensitization. These results may suggest that (1) autoallergic mechanism should never be ignored. (2) splenomegaly in chronic liver diseases should not be considered from hemodynamic disturbance alone, but one of the important reacting sites where many factors including antigen antibody reaction are involved.
|
61,902
|
A comparative study of the effects induced by MCN-A-343 and acetylcholine on the isolated toad rectus abdominis.
|
McN-A-343 (McN), a non nicotinic ganglionic stimulant, induced slow contractile responses of the toad rectus abdominis. A relaxation was also observed when large doses were added in the presence of a contraction caused by acetylcholine (Ach). The relaxation induced by McN could not be overcome by increasing Ach concentration. Bell-shaped log dose-response curves were obtained for McN. d-Tubocurarine caused an unusual change on these curves, suggesting an indirect action of the agonist. This possibility was corroborated by the fact that hemicholinium, procaine, and cold storage of the muscle caused a marked decrease of the organ sensitivity to McN but not to ACh.
|
61,903
|
Factors affecting the excretion of 14C-dicumarol in the bile of rats.
|
1. After i.v. injection of equivalent doses of 14C-dicumarol, male rats excreted about 2 1/2 times more radioactivity in bile (9.3 +/- 0.7% in 2 hr) than did females (3.9 +/- 0.4% in 2 hr). 2. Exogenous agents: while 24 hr pretreatment with benzpyrene or 3-methylcholanthrene did not alter the excretion of 14C-dicumarol and its metabolities in bile, pretreatment with carbon tetrachloride reduced radioactivity in the bile of male rats 60%. Following single rapid injection of sulfobromphthalein (BSP), the radioactivity in bile, decreased 70%. 3. Most of the radioactivity in bile (80-90%) was present in metabolized form regardless of the dose, the sex of the rat, or the exogenous agent used.
|
61,904
|
Prognostic value of serum alpha-fetoprotein in fulminant hepatic failure including patients treated by charcoal haemoperfusion.
|
Serum alpha-fetoprotein (AFP) levels have been measured sequentially by a radio-immunoassay method in 64 patients with fulminant hepatic failure. In 15 of the 64 patients (23%) AFP levels were raised but in only two did they exceed 500 ng/ml. Of the 23 survivors 11 (48%) had raised AFP levels compared with four of the 41 (9-8%) fatal cases (P less than 0-005). This rise in AFP levels was found early after the development of grade IV coma and constitutes an encouraging prognostic sign at a time when the liver function tests and EEG are unhelpful. A radioimmunoassay must be used if these small but significant rises in plasma concentration are to be detected. Twelve patients survived without showing a rise in plasma AFP at anytime during the illness. The four fatal cases who had raised AFP levels all had serious complications of fulminant hepatic failure. Charcoal haemoperfusion did not seem to increase the survival of AFP negative patients.
|
61,905
|
Autoimmune reaction to a liver specific membrane antigen during acute viral hepatitis.
|
Lymphocyte cytotoxicity for isolated hepatocytes has been demonstrated in 93% of cases of acute viral hepatitis tested within two weeks of the onset of symptoms. The frequency of cytotoxicity during this time was similar for HBsAg positive and negative cases. However, after this time it was significantly higher in HBsAg positive than negative cases, 90% and 25% respectively (P less than 0-01). Cytotoxicity was found in B-cell, but not T-cell, enriched fractions of lymphocytes, compatible with an antibody-dependent K-cell mediated reaction. In two cases the assay remained positive on retesting six months later, and follow-up liver biopsies showed the features of chronic aggressive hepatitis. These findings suggest that, in addition to the known immunological reactions against viral antigens that occur during the acute phase of viral hepatitis, an autoimmune reaction directed against a liver specific protein is also initiated; and if this reaction persists then chronic hepatitis may develop.
|
61,907
|
The ultrastructure of formed white blood elements (neutrophils) in schizophrenia.
|
A comparative electronmicroscopic study of neutrophils in schizophrenic patients and in healthy control subjects has revealed a certain difference in the ultrastructure of blood cell formation. This difference concerns the coarse-grained chromatin, the osmiophility of nuclear membrane, the enlargement of perinuclear halo, the enlightenment of matrix, the enlargement of glycogen granules, the swelling of mitochondria, the change in the amount of free ribosomes, an increase in the number of azurophilic granules and a decrease in the specific ones.
|
61,908
|
[The acid-base equilibrium during mouse lymphoblastic leukemia].
|
In transplantable and in spontaneous lymphoblastic mouse leukemia blood pH, PCO2, TCO2 and BB were examined. Spontaneous Gross-leukemia in AKR mice was found to develop in its final phase respiratory acidosis. Transplantable (TAL) leukemia of AKR mice presents from the onset a tendency toward respiratory acidosis. "L-1210"-leukemia, on the contrary, was shown to alcalise the recipients during the first 8 days after inoculation, later on it can bring about an acidosis. The pH-deviations in "L-1210"-leukemia display a respiratory character in syngeneic DBA/2J recipients, whereas in semiallogeneic recipients the observed changes are metabolic or mixt in nature. This finding strongly argues for the importance of histocompatibility. Intranodally inoculated animals distinctly differ in their parameters in comparison to intravenously and intraperitoneally recipients, hence, an important role of the tissular-milieu which is put first in contact with the leukemic factor must be concluded.
|
61,910
|
[The cerebral sensitivity to "meningosis-prophylaxis" with 198Au radiogold according to EEG findings].
|
35 children (16 girls and 19 boys) at the age of 1 11/12 to 16 11/12 with acute leukaemia were injected intrathecally with 198Au-radiogold colloids (HOECHST-BEHRING) for "prophylaxis of meningosis". The colloid size of the isotope amounted to 5 or 30 nm, the applied activity lay between 1.4 and 3.12 mCi. According to a dosage estimation made with the help of LOEWINGERS formula 1 mCi of radiogold corresponds to approximately 1200 rad. Clinical observations, such as headaches, vomiting or fever up to 39 degrees C, could only be found in 6 children (17.1%) during the first 24 hours. All symptoms subsided quickly and without any sequels. Even retarded complications could not be detected. An electroencephalogram was made from all children before and after applying radiogold (1-8 d afterwards). After the injection of radiogold the majority of children had no change of findings in the electroencephalogram, 11 children even showed a tendency towards an improvement up to normalisation. Only 4 children had a deterioration of findings with unspecific disorders or appearances suspected of peak potential discharges. Simultaneously an accumulation of clinical complaints could be found. Judging from the clinical and electroencephalographic behaviour of our patients no absolute neurotoxity of radiogold could be ensured.
|
61,911
|
[The occurrence of Heinz bodies in the erythrocytes of persons exposed to low dose radiation during work].
|
274 persons were examined by the provocation test of Heinz's bodies according to BEUTLER. 168 of them were working under x-rays exposure. No correlation could be identified between the dosage and the presence of Heinz's bodies in the lower range of the dosage related to the annual x-rays load and the integrated total exposure.
|
61,914
|
[The question of bone marrow cell proliferation in Di-Guglielmo's syndrome].
|
In a patient with a di Guglielmo's syndrome DNA was determined cytophometrically in the bone-marrow cells. The results show that the proliferation of paraerythroblasts is increased in the phase of erythremia in comparison to normal erythropoiesis. The proliferation of myeloblasts during the stage of myeloblastomatosis, however, is low similar to the majority of acute leukaemias. The examinations confirm the view that the di Guglielmo's syndrome represents a form of acute leukaemia.
|
61,915
|
Changes in the blood parameters of an air-breathing fish during different respiratory conditions.
|
Some of the blood parameters recorded in an air-breathing eel, Amphipnous cuchia under normal respiratory condition during non-breeding period (September-April) are haemoglobin (Hb) concentration 19.26%, haematocrit value 56.16%, RBC number 1.71 million/mm3, RBC size 18.86 X 9.70 mum, mean corpuscular haemoglobin (MCH) 113.4 ng, mean corpuscular haemoglobin concentration (MCHC) 34.2%, blood sugar 77 mg% and ascorbic acid 0.435 mg%. The higher concentration of haemoglobin (19.26%) appears to be related to its obligatory air breathing habit and habitat in a water of low oxygen content. Though a definite trend of increase in the haemoglobin and haematocrit concentration with an increase in the body weight of the fish was lacking, variations were clearly marked related to intrinsic activity of the fish connected with different respiratory conditions. Asphyxiation in a submerged but continuous flow of water (liter/h) for 5 1/2 h resulted in an increase in the above-mentioned parameters to an appreciable extent. These increases were 0.23 million/mm3 in the number of erythrocytes, 6.16% in haemoglobin concentration, 10% in haematocrit value, 20% in blood sugar and 35% in ascorbic acid content. The mean corpuscular haemoglobin showed a decline of 6.2%. Exclusive aerial breathing for 5 1/2 h also caused 7.4% increase in haemoglobin concentration, 9.4% in haematocrit value, 0.14 million/mm3 in RBC number, 20% in blood sugar level, 9% in ascorbic acid content but almost no change in mean corpuscular haemoglobin. The average surface area for diffusion of gases appeared to have reduced by 6.8 mum2 per RBC.
|
61,916
|
[Studies on blood morphology in the European eel (Anguilla anguilla). I. Erythrocytes and their developmental stages].
|
By means of heart tapping we produced a larger loss of blood in the European eel, Anguilla anguilla. This resulted in enriching the peripheric blood with erythroblasts and proerythrocytes. By panoptic staining erythroblasts, proerythrocytes and mature erythrocytes could be prepared and described. By the aid of supravital staining it was possible to detect mitochondria and Substantia granulofilamentosa in all stages of development. Phase contrast observations proved that the erythrocytes of Anguilla anguilla do not possess any locomotion ability. Cytochemical investigations showed that the erythrocytes weakly or very weakly react to acid phosphatases, lipids and ribonucleic acids and positively to unspecific esterases. The artificially produced loss of blood and the following continuous extraction of blood gave indications of how rapidly the erythrocytes form and how much time their maturing takes. 48 hours after tapping erythroblasts appeared in large amounts. The number of proerythrocytes increased 24 hours later. The transformation of proerythrocytes into mature erythrocytes does not take more than 48 hours. The loss of erythrocytes caused by heart tapping is already compensated six days later by new growth. During this investigation division processes in erythrocytes were observed. These are endomitotic or amitotic division or mitotic ones which are very rarely observed.
|
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