Archives for: April 2004
STUDY: Busiest radiologists--those who had evaluated the most mammograms--did not necessarily do the best job at identifying signs of breast cancer.
JOURNAL: Journal of the National Institute of Cancer 2003;95:250-252.
AUTHORS: Dr. Craig A. Beam
ABSTRACT: Conflicting information on what factors determine radiologists' accuracy in reading mammograms may have some women wondering what they can do to ensure a correct diagnosis.
COMMENTARY: There are a number of steps women can take to boost the accuracy of the breast cancer screening test.
First and foremost, women should attempt to go to the same breast cancer screening clinic year after year.
If that is not possible, women should obtain the X-rays from their previous mammograms for comparison sake.
For younger women, they should avoid getting a mammogram while they are menstruating because the breast tissue undergoes changes during this time that can affect mammogram accuracy.
Younger women are better off scheduling mammograms during the follicular phase of their cycle--the first and second week after the first day of their period.
It is also important to stay as still as possible during a mammogram.
Women need to be warned that when getting a mammogram, it can hurt...but despite the unpleasantness they need to hold really, really still to avoid motion artifacts on the X-ray.
Plus, the more the breast is compressed the better the image and the less radiation required.
Older women who are taking hormone replacement therapy should be aware that the treatment may reduce the accuracy of mammography by increasing breast density.
STUDY: Honey prevents bacterial growth
JOURNAL: Journal of Wound, Ostomy, and Continence Nursing (2002;29:295–300).
ABSTRACT: Topical application of honey is beneficial in the treatment of wounds and burns.
COMMENTARY: Honey is a highly concentrated sugar solution produced by honey bees, primarily from the nectar of plants. It is composed of carbohydrates (sugars), water, enzymes, amino acids, pigments, pollen, wax, and other trace constituents from both bees and plants.
Honey has been used in the treatment of burns and wounds for many centuries, with documents describing this use dating back to 1700 BC.
A number of properties inherent to honey might contribute to its ability to fight infection and promote healing. Its high sugar content allows it to draw infection and fluid from wounds by a process called “osmosis.”
Honey prevents bacterial growth through its acidic pH and through the work of an enzyme that produces small amounts of hydrogen peroxide. Its ability to keep the area around a wound moist and protected promotes fast healing and prevents scarring.
Honeys also contain components from the specific plants used by the bees in their production, and it is speculated that some of these components might further add to the antibacterial and wound-healing effects of certain honeys.
The process of pasteurization, used to sterilize commercial honeys, destroys the enzyme involved in the production of hydrogen peroxide, rendering these honeys less antibacterial. Raw honeys maintain their enzymes, and honeys produced for therapeutic use are sterilized through an irradiation process that does not damage their constituents.
There are currently two therapeutic honeys available: Medihoney of Australia and Active Manuka Honey of New Zealand. Both are derived from bees using the flowers of tea trees (Leptospermum spp.) as their source.
A number of studies have confirmed the antibacterial effects of honey in test tubes. One study found that different honeys had different levels of activity against specific bacteria. Studies on humans have reported that honey used as a wound dressing reduced infection, inflammation, pain, and odor, and promoted easy removal of dead tissue and rapid healing with little scarring.
Fifty-nine people with chronic wounds and ulcers participated in one preliminary study described in this review. The group included people with diabetic ulcers, burns, traumatic ulcers, gangrene, and other types of wounds. All had been treated with commercial wound dressings and antibiotics for periods of between one month and two years without results.
Although 51 of the 59 wounds had been infected prior to honey treatment, all were free of infection within one week of starting honey dressing applications. In addition, inflammation and odor were markedly reduced and healing rapidly ensued.
JOURNAL: Ann Intern Med 2003;138. www.annals.org<br />
AUTHORS: Dr. Bent
ABSTRACT: Compared with other herbal products, ephedra is far more likely to cause adverse effects.
COMMENTARY: Based on an analysis of reports to the American Association of Poison Control Centers, Dr. Stephen Bent and his colleagues discovered that products with ephedra accounted for 64% of the herb-related adverse reactions in 2001.
This finding is remarkable, the authors note, given that less than 1% of herbal products sold that year contained ephedra.
Although awareness of the potential dangers of ephedra is growing among consumers, many still purchase ephedra-containing products.
Using data from case reports alone, it has been difficult to definitively link ephedra with various adverse effects, Dr. Bent said. But the finding that ephedra is linked to far more side effects than other herbs adds support to the theory that the substance can be dangerous, he said.
How ephedra stacked up against other products varied from herb to herb, Dr. Bent and his colleagues note -- but in all cases, it outnumbered other products in adverse reactions by a factor of at least 100.
My Comment is that Ephedra has always been the whipping boy of the herbal industry. Used properly I have never had a problem with it. It is the abuse of it that causes the issue. Like everything else I don't see alcohol or tobacco being banned and these two items cause far greater adverse outcomes.
STUDY: Link between birth size and breast cancer
JOURNAL: BMJ 2003;326:248-251.
AUTHORS: Dr. Valerie McCormack
ABSTRACT: Birth size, as determined by birth length and head circumference, is directly related to the risk of developing premenopausal breast cancer.
COMMENTARY: However, the link between birth size and breast cancer was not seen among women older than 50 years of age, lead author Dr. Valerie McCormack, from the London School of Hygiene and Tropical Medicine, told Reuters Health.
Dr. McCormack said that the current study, reported in the February 1st issue of the British Medical Journal, was undertaken to investigate how conditions in the womb, which can influence birth size, might also influence the risk of breast cancer later in life.
Based on the findings, Dr. McCormack suggested that larger infants may have been exposed to different levels of growth hormones in the womb, and that the in utero environment may have played a role in determining breast cancer risk.
In the study, the researchers reviewed information from 5358 singleton females born between 1915 and 1929. Data from the Swedish Cancer Registry were analyzed to determine which subjects developed breast cancer.
The researchers found that 359 of the subjects developed breast cancer, with a median age at diagnosis of 62 years.
Women who weighed at least 4000 g at birth were 3.5 times more likely to develop breast cancer than were women with birth weights below 3000 g.
Although birth weight was related to breast cancer later in life, the link was no longer significant after accounting for birth length and head circumference. In contrast, birth length and head circumference remained significant predictors of future disease even after adjusting for birth weight.
Among infants of similar birth size, the researchers found that the gestational age at birth was inversely related to the risk of breast cancer.
These findings suggest that the hormones that influence body length and head circumference also play an important role in later cancer risk, Dr. McCormack noted.
JOURNAL: 28th International Stroke Conference: Abstract P327. Presented Feb. 14, 2003.
AUTHORS: Jinzhou Tian, MD
ABSTRACT: Ginseng may help improve memory in patients with mild dementia following a stroke, according to the results of a randomized pilot study reported at the American Stroke Association's 28th International Stroke Conference.
COMMENTARY: Chinese ginseng strikingly improves learning and memory following transient cerebral ischemia in rats. It increases the activity of brain acetylcholine and choline acetyltransferase in aged mice, while reducing the activity of acetylcholinesterase in the cerebral cortex and hippocampus.
In this randomized, double-blind, controlled clinical trial, 40 patients with mild and moderate dementia after ischemic stroke (26 men and 14 women) received one tablet of compound Chinese ginseng (n = 25) or one 40-mg tablet of almitrine + raubasine (n = 15), three times daily for 12 weeks.
The ginseng compound was extracted from Chinese ginseng roots, leaves, and panax notoginseng. The combination of almitrine and raubasine is thought to increase oxygenation in brain tissue.
After treatment with Chinese ginseng, mean scores on the HVLT and total memory scores increased significantly (P < .05 and P < .001, respectively).
Improvements in episodic memory function assessing immediate and delayed story recall, delayed word recall, verbal learning and verbal recognition, and visual recognition were greater in the ginseng group than in the almitrine + raubasine group.
"There is currently great interest in studying herbs used in traditional forms of medicines, and the problem of dementia after stroke is a significant one," says Robert J. Adams, MD, chairman of the Stroke Council of the American Heart Association. "This work showing that ginseng may improve memory after stroke needs to be further studied, with larger sample sizes. A placebo-controlled study would also be the next step.
STUDY: Procedure detects change in structure of blood protein
AUTHORS: Dr. Steven Gutman
ABSTRACT: Doctors have won federal approval of a new blood test to help them tell which patients suffering chest pain aren’t really having a heart attack.
COMMENTARY: Up to 5 million people go to U.S. emergency rooms each year complaining of chest pain, but only about one in five is having a heart attack, according to the Food and Drug Administration.
Other ailments, from severe indigestion to gallstones, can mimic a heart attack — and up to half of chest-pain patients have atypical symptoms or test results that make diagnosis a challenge, said Dr. Steven Gutman, FDA’s chief of clinical tests. In such cases, it can take from eight to 24 hours before emergency room doctors are sure the person’s heart is OK and send him or her home.
The FDA approved a simple blood test that, when added to heart checks, could greatly improve doctors’ ability to rule out a heart attack and send those patients home sooner. The $30 test, made by Ischemia Technologies Inc. of Denver, uses the metal cobalt to hunt changes in a blood protein that occur during a heart attack.
Today, two tests are standard for heart-attack detection: an EKG to measure the heart’s electrical activity, and a blood test that detects troponin, a protein present in the blood after a heart attack.
In a study of 200 patients, doctors were 50 percent accurate in ruling out a heart attack using just an EKG and troponin test. But when they added the new test, doctors accurately ruled out a heart attack 70 percent of the time, FDA said.
JOURNAL: Environmental Protection Agency
AUTHORS: Ramona Trovato
ABSTRACT: Children under 2 years of age have a much greater chance of getting cancer from exposure to certain chemicals than do adults, the Environmental Protection Agency concludes in a new risk assessment.
COMMENTARY: New guidelines proposed by the EPA on cancer risk and children would require EPA scientists for the first time to take into account the greater vulnerability of the very young in determining how some cancer-causing chemicals are to be regulated.
According to the analysis, which focused chemicals that cause damage to genes, the risk of a future cancer is 10 times greater for a child under age 2 than for an adult who is similarly exposed.
Children from 3 to 15 years of age face a risk at least three times greater than adults when exposed to these chemicals, the proposed EPA guidance said.
The analysis was confined to so-called mutagenic chemicals that cause damage to genes thereby making a person more susceptible to getting cancer later in life.
But EPA scientists said children may well be more vulnerable when exposed to other types of cancer-causing chemicals as well, although the scientific data is not yet sufficient to make any conclusions on that.
Nevertheless, the proposed guidance would represents a major change in how cancer risk to children is viewed by EPA regulators. Currently the agency assumes in when assessing a chemical that children are no more vulnerable to cancer than adults if exposed to the substance.
"This (new assessment) is really a significant step forward in understanding how environmental exposure affects our children," said Ramona Trovato, an EPA official who has spent the last five years studying environmental pollution and children.
The proposed guidelines on children is to be reviewed by the EPA science advisory board, probably in May, with a final guidance likely to be issued this summer, said Bill Farland, the EPA's acting assistant administrator for science.
"We think this guidance on assessing children's cancer risk is going to evolve for a number of classes of compounds ... as we get more information. "We have long talked about the need to assure that we're protecting sensitive sub-populations and sensitive life stages."
The EPA assessment notes that children generally are expected to have exposures to chemicals that are different from adults because differences in their size, physiology and behavior. Children and adults exposed to the same concentrations of a chemical also may receive different internal doses because of differences in intake and absorption rates, the assessment said.
The EPA assessment was based mainly on a review of animal studies involving five mutagenic compounds and from data collected in studies of survivors of atomic bomb blasts in Japan at the end of World War II, said James Cogliano, an EPA scientist.
Most of the chemicals that were studied involve industrial applications, ones to which infants would not likely be easily exposed, said Farland.
One of them, benzopyrene, is a carcinogen found in cigarette smoke and auto exhausts; another, benzidine is used in the manufacture of dyes, while a third, vinyl chloride, is used in making plastics.
But the findings suggest, when more studies come in, the same disparity on risk between adults and the very young may well be observed although in existing studies "you see mixed results," said Cogliano. "Sometimes there was a higher cancer risk, sometimes there was not."
"We're very happy that they've recognized that children under 2 years of age are really very susceptible," said Jennifer Sass, a scientist in the public health program at the Natural Resources Defense Council.
She and other environmentalists, however, were not as enthusiastic about a separate set of guidelines on evaluating cancer risks.
That guidance, which is close to being made final, attempt to refine and make more precise the methods used by EPA scientists to evaluate cancer risks for all age groups.
EPA officials said the new guidelines will more accurately reflect cancer risks than methods now in use. But environmentalists worried these new guidelines might produce less protection by making it harder to declare a chemical a carcinogen.
JOURNAL: BMJ. 2002;325:1183-1184, 1195-1198, 1199-1201, 1212-1213
AUTHORS: Louise Arseneault, Stanley Zammit
ABSTRACT: — Three cohort studies published in the British Medical Journal suggest that frequent cannabis use increases the risk of developing depression and schizophrenia in later life.
COMMENTARY: This study suggests that girls who use cannabis as teenagers are more likely to develop anxiety or depressive disorders. Among 1,601 students from 44 secondary schools, frequent cannabis use predicted later depression and anxiety, especially in girls.
By age 20, 60% of participants had used cannabis, and 7% used it daily. After adjustments for use of other substances, daily cannabis use in young women was associated with a more than fivefold increase in risk of later depression and anxiety (odds ratio [OR], 5.6; 95% confidence interval. Weekly or more frequent use as a teenager doubled later risk.
A 1969-1970 survey of 50,087 male Swedish conscripts, aged 18 to 20 years, showed that use of cannabis increased the risk of schizophrenia by 30% (adjusted OR for linear trend. This study also suggests a dose relationship with the development of schizophrenia, because the adjusted OR for using cannabis more than 50 times was 6.7.
"Cannabis use is associated with an increased risk of developing schizophrenia, consistent with a causal relation," write Stanley Zammit, from the University of Wales College of Medicine in Cardiff, the UK, and colleagues. "This association is not explained by use of other psychoactive drugs or personality traits relating to social integration."
Although the authors suggest that the preponderance of evidence is that occasional cannabis use has few harmful effects overall, repeated use is a potentially serious risk to mental health, especially in the presence of other risk factors for schizophrenia. These risks should be recognized in light of current trends to liberalize or even legalize cannabis use.
The third study showed that using cannabis in adolescence increased the likelihood of experiencing symptoms of schizophrenia in adulthood. Those who used cannabis by age 15 years were at greatest risk.
"Our findings suggest that cannabis use among psychologically vulnerable adolescents should be strongly discouraged by parents, teachers, and health practitioners," write Louise Arseneault, from King's College in London, U.K., and colleagues. "Policy makers and law makers should concentrate on delaying onset of cannabis use."
JOURNAL: Society of Cardiovascular and Interventional Radiology
AUTHORS: James Spies
ABSTRACT: Using tiny spheres to block the blood supply of uterine fibroids may be a possible alternate to hysterectomy, a surgical removal of the uterus, new study findings suggest.
COMMENTARY: Uterine fibroids can cause excessive menstrual bleeding, pelvic pain and frequent urination. The tumors occur in about 25% of all women and are the leading cause of hysterectomy in the US. African-American women are at even higher risk for pain and infertility from the growths.
In a procedure called uterine fibroid embolization (UFE), particles are used to block the blood supply of fibroids, shrinking the benign tumors.
The data suggests that women can get relief from fibroids without having to undergo major surgery. It is not recommended for women who are considering pregnancy within a year or two of the procedure.
In a separate study, a Georgetown researcher reviewed medical records and determined that the cost for UFE was slightly less than open surgery to remove fibroids. Including imaging, hospital and physician fees, UFE cost about $6,713 on average, compared with $8,204 for surgery.
STUDY: Evidence that the organ may indeed harbor stem-cell reserves capable of regenerating damaged tissue.
JOURNAL: The New England Journal of Medicine 2002;346:5-15, 55-56
AUTHORS: Dr. Piero Anversa
ABSTRACT: In a study that turns on its head the traditional view that the heart cannot help heal itself, scientists have found evidence that the organ may indeed harbor stem-cell reserves capable of regenerating damaged tissue.
COMMENTARY: Their study of men who received heart transplants from female donors revealed that primitive cells from the recipients migrated into the donor hearts, after which new muscle cells and small blood vessels formed. The researchers were able to pin down the phenomenon by finding a considerable number of cells in the donor heart that bore the Y chromosome--the "male" sex chromosome, which could only have come from the transplant recipients themselves.
Dr. Piero Anversa of New York Medical College in Valhalla said his team believes primitive cells moved to the donor hearts from the remaining portions of the transplant recipients' own hearts, although the study does not prove this. Anversa explained that his team could not rule out the possibility that the cells traveled to the heart from the bone marrow, which contains the stem cells that give rise to blood.
The study indicates that the heart possesses a population of cardiac stem cells...implying that the heart has the capacity to regenerate itself.
And that idea, Anversa noted, is at odds with the cardiology "dogma" that there is no such thing as cardiac stem cells--populations of immature cells within the heart that have the potential to divide, proliferate and replace mature cells killed off by heart attack and disease.
Now that there is strong evidence of the heart's regenerative capacity, scientists can study the possibility of harnessing this self-healing potential to treat damaged hearts, according to Anversa.
He and his colleagues report their findings in the January 3rd issue of The New England Journal of Medicine.
The study looked at autopsied tissue from eight men who died sometime after receiving a heart from a female donor. The patients had lived with their new hearts for anywhere from 4 to 552 days.
Anversa's team found that up to 20% of the cells in the men's heart muscle and small blood vessels called arterioles and capillaries bore the Y chromosome. Even the patient who died 4 days after his transplant had Y-bearing cells in the donor heart.
According to the researchers, this suggests that the recipients' own primitive cells moved into the foreign heart and matured to aid in the "remodeling" of the organ.
In addition, when they looked at a small group of autopsied normal hearts, the investigators found small populations of immature cells. This gives further evidence that there is a stem-cell population normally there that helps regenerate the heart.
The discovery of primitive cells in normal hearts is one of the most intriguing findings of this remarkable study. It does indicate that primitive cells are a component of normal hearts.
And if heart stem cells can indeed form new heart tissue, it is still unclear what "mobilizes" them into action. His team is currently using animal models to study what signaling mechanisms--such as growth factors--are needed.
If researchers can figure out how to mobilize self-repair cells in the heart, they could become an important weapon against a "host of disorders" including coronary artery disease and heart muscle conditions.
The therapeutic implications would be enormous, since at least 600,000 Americans develop heart failure every year and many of them die within 2 to 3 years.
STUDY: Study concludes special covers ‘not worth the price’
JOURNAL: New England Journal of Medicine
AUTHORS: Thomas Platts-Mills
ABSTRACT: Bedding covers designed to keep dust mites out of the air don’t reduce hay fever and asthma symptoms.
COMMENTARY: The covers which, sell for $50 to $100 in the United States, screen out mites and their byproducts while allowing air to flow. They are sold as one way to help sensitive individuals reduce the risk of allergic reactions.
In a one-year test of 1,122 adults with asthma, British doctors found that volunteers who used the bedding had no more real improvement in their symptoms than people who used standard bedding.
The second, smaller study, led by researchers in the Netherlands, found that hay fever symptoms did not improve among the 114 people who used mite-proof bedding covers, compared to the 118 who did not.
STUDY: Make sure those collars aren't tight
JOURNAL: British Journal of Ophthalmology
AUTHORS: Dr Robert Ritch
ABSTRACT: Men should think twice about how tight they wear a necktie because it could increase their chances of developing glaucoma.
COMMENTARY: A tight necktie raises blood pressure in the eye, which is a leading risk factor in the illness that can lead to damage to the optic nerve and loss of vision.
A tight necktie increases IOP (intraocular pressure) in both normal subjects and glaucoma patients and could affect the diagnosis and management of glaucoma.
In addition to raising the risk of glaucoma, donning a tight necktie during an eye examination could lead to a false diagnosis of the illness.
The researchers suspect that a tight necktie constricts the jugular vein, which increases blood pressure and IOP.
Bottom line is to make sure to wear shirts with a collar that is not tight.