High total histone/deoxyribonucleic acid ratios for rat liver nuclei

The ratios of total histone to DNA for rat liver nuclei isolated by four methods as well as for calf liver nuclei isolated by one method were determined by obtaining the ratios of the total areas of the electrophoretic histone peaks for the liver nuclei to the corresponding total area given by a known amount of standard calf thymus histone. Ratios of total histone to DNA of approx. 2 for rat liver nuclei isolated at pH3.8 or 5.8 and for calf liver nuclei isolated at pH3.8 were confirmed twice by the above procedure and also by direct measurement, by the method of Lowry et al. (1951), of histone extracted in 0.2m-H(2)SO(4). The histones of calf thymus, calf liver and rat liver were characterized by their amino acid compositions and by polyacrylamide-gel electrophoresis.     

MALNUTRITION AND BRAIN DEVELOPMENT: CEREBELLAR WEIGHT, DNA, RNA, PROTEIN AND HISTOLOGICAL CORRELATIONS

Abstract— Rat pups were reared in litters of 20 and litters of 6 to study effects of malnutrition on cerebellar development. Cell production and cell content were determined by assaying for DNA, as a measure of cell number, and RNA and protein, as indicators of cell constituents. By comparing DNA contents at 3, 4, 8, 11, 14, 17, 21, and 28 days after birth, we concluded that (a) there is little nutritional reserve at birth since significant differences appear by day 4, (b) most relative differences between groups appeared by day 8, with absolute differences increasing to day 21, and (c) there is partial recovery of cell number and cell constituents in the malnourished rats between 21 and 28 days.
Areal measurements of histological preparations showed that malnutrition resulted in less total area in cerebellar midsagittal sections at days 8, 11. and 14. In malnourished animals, the germinal matrix area of the cerebellum, the external granular layer, was smaller on the 8th postnatal day, the same on the eleventh day, and larger on the fourteenth day when compared with that of well fed animals. At all three ages alterations could be discerned in the distribution of cells between the mitotic external mantle and nonmitotic internal matrix portions of the external granular layer.
Further studies involving exchanging animals between large and small litters at various ages indicated that the time around days 4 to 8 is most sensitive to malnutrition. The results suggest a process in which malnutrition exerts its maximum effect by a slowing of cell production in the external granular layer in the initial exponential growth phase. It is likely that an adaptation occurs immediately in the external granular layer which subsequently permits a partial recovery of cerebellar growth between days 21 and 28.     

A basic experimental approach in perspective of pineal and melatonin involvement in photoperiod-induced alteration of spermatogenesis in toad (Bufo melanostictus)

Blinding decreases spermatogenesis along with Leydig cell degeneration in toad. Pinealectomy decreases spermatogenesis with an increase in Leydig cell activity. Melatonin decreases spermatogenesis as well the Leyding cells. Possibly pineal and melatonin possess an inverse relationship with light and inhibit testis.     

Characteristics of a cholera phage

The basic physical, chemical and physiological properties of a group II cholera phage belonging to Mukerjee's classification has been described.     

Synthesis and anticancer activity of 2-benzylidene indanones through inhibiting tubulin polymerization

In an attempt to discover a potent and selective anticancer agent, gallic acid has been modified to benzylidene indanones as tubulin polymerization inhibitors. These compounds were evaluated against several human cancer cell lines and also evaluated for inhibition of tubulin polymerase in in vitro assays. Three of the analogues exhibited strong cytotoxicity against human cancer cell lines IC(50)=10-880 nM and also showed tubulin polymerization inhibition (IC(50)=0.62-2.04 μM). Compound 9j, the best candidate of the series was found to be non-toxic in acute oral toxicity in Swiss-albino mice up to 1000 mg/kg dose.