  By comparison of recent direct measurements of the temperature dependence of
the upper critical field $H_{c2}$ in an Y-123 high temperature superconductor
with the scaling analysis of magnetization data, collected in fields H << H_c2,
we demonstrate that that the temperature dependence of the Ginzburg-Landau
parameter kappa is negligible. Another conclusion is that the normalized
temperature dependence of H_c2 is independent of the orientation of the
magnetic field in respect to crystallographic axes of the sample. We also
discuss that isotropy of the temperature dependence of H_c2 straightforwardly
follows from the Ginzburg-Landau theory if kappa does not depend on
temperature.
