About 4-day rhythm of proliferative activity of fibroblast-like cell cultures isn't endogenous and don't depend from the variations of Earth's magnetic field.

A study of the 4-day rhythm of the proliferative activity of the embryonic fibroblast-like cells in the logarithmic growth phase was carried out. It was shown that in cell cultures obtained on different days from embryos of different ages, the phase of the 4-day rhythm coincides. In vitro the maxima of the proliferative activity were consistent with the minima of the motor activity of mice.

Sex differences of inflammatory and immune response in pups of Wistar rats with SIRS.

It is a common fact, that the content of sex hormones in humans and animals varies in different age periods. The functional state of the immune system also changes with age. However, sex differences studies of inflammatory and immune responses during puberty prevail in literature.