Co-existence of inhibitory and stimulatory factors modulating cell proliferation in rat liver cytoplasm.

Factors that inhibit and stimulate cell proliferation were found to coexist in rat liver supernatant. The inhibitory and stimulatory factors were separated by ethanol fractionation. Both factors were sensitive to heat- and trypsin-treatment. The activity of the inhibitor was diminished by partial hepatectomy. The inhibitor from normal livers inhibited DNA and RNA synthesis in the L-cell system, but the same fraction from regenerating livers caused little or no inhibition of nucleic acid synthesis. The stimulatory factor from regenerating livers had a stronger effect on cell proliferation than that of normal livers. Furthermore, the inhibitor from normal livers depressed DNA synthesis in vivo in regenerating livers

ウンドウ センシュ ニヨル イキ コラエ ノ トレーニング コウカ ニツイテ

This research is the analysis of the effect of breath-holding training performed by students belonging to the sport-clubs of our universities. In this reserach, the movement of records of breath-holding time both one week and two months after finishing was analyzed and, at the same time, the correlation of length of the breath-holding time with physical characteristics such as height, vital capacity, weight, pulse, circumference chest, body surface area and breath number perminute was also analyzed. The steps taken for this research are as follows : The training of breath-holding was perforomed by students aged from 18 to 20 grouped into two ; one group is composed of those who consume their physical energy in a moment and the other who consume their physical energy continuously for a long period. And the training of breath-holding was performed ten times in a series. Following results were obtained. 1) The effect of breath-holding training is positive after successive training. 2) The records of breath-holding time during the training are higher with the second group than those with the first group. 3) The movement of records after the training is more noticeable with second group than with the first group ; the records decline more noticeably with second group. 4) The length of breath-holding time is correlated with vital capacity among other physical characteristics

The visual evoked field potential in the congenital acallosal mouse

The congenital absence of corpus callosum has been recently found to occur among some mice of the ddN strain in our laboratory. In this experiment, the differences of the visual evoked potentials among the normal corpus callosum, callosal hypogenesis and agenesis in ddN strain mice were investigated. One-Hz- flash stimulations were given on the left eye through a glass fiber connector from the EEG stimulator. Under Nembutal anesthesia, two hundred times of average evoked field potentials were recorded from the contralateral and ipsilateral visual cortices. Electrophysiologically, the normal mice showed complete decussation on the opic chiasm. On the other hand, the complete acallosal mice could be classified into two types, such as those of complete decussation and those of absence of optic chiasm. In the complete decussation of acallosal mice, the latency, peak latency and duration of these potentials from ipsilateral side significantly prolonged, and the amplitude of the potentials extremely diminished. In the absence of optic chiasm of complete acallosal mice, the potentials were obtained only in ipsilateral cortex. After amputation of the corpus callosum in the normal mice, the visual evoked field potential showed similar to acallosal mice. However, in the hypogenesis of corpus callosum, there was no significant difference in the potentials compared with the normal mice

Analysis of the action of Illudin S: Effects of Illudin S on surface structures of L(929) fibroblasts

The effects of Illudin S (a toadstool poison) on surface structures of L(929) mouse fibroblasts were studied by scanning electron microscopy. Illudin S in a concentration of 1 ng/ml strongly inhibited cell proliferation, but had no effect on surface structures of L cells through all the cell phases. These results indicate that the biological effects of Illudin S were not manifested by changes in the cytoskeletal system, the cell ability to attach to the substrate, of the surface structures of the cell. It is suggested that the cellular sensitive sites to Illudin S are inside the cell

DNA synthesis inhibiting factors of muscle-cornin and cornea-cornin

An attempt was made to purify the active principle (s) of cornea-and muscle-cornin, inhibiting the DNA synthesis in cultured mammalian cells. Each of the two kinds of cornin was separated into the dialysable (D) and the undialysable (U) fraction, which were further fractionated by the use of Sephadex gel. The inhibitory rate of these fractions was indicated by percent of control estimating the incorporation of (3)H-thymidine into cells or DNA fractions of cultured rat liver cells, line RLN-10, during the incubation period of 6 hours at 37℃ in the presence of respective fractions at the final concentration of 0.5 percent in the culture medium. As a result, the highest activity was shown in the D-Ⅱ fraction of muscle-cornin, which corresponded to the elution peak of the inorganic phosphate, and in the D fraction of cornea-cornin, The activity, however, was also shown in several other fractions. These data suggest that the inhibitory effect of cornin on the DNA synthesis in mammalian cells is due to combined effects of several factors present in cornin