Regulation of the cell cycle of B-lymphocytes in mice by substances elevating the levels of intracellular cAMP and cGMP

Spontaneous velocity sedimentation of B lymphocytes activated by intraperitoneal injection of ovalbumin into mice was used to obtain cell cycle synchronized cells, evidenced by differences in the incorporation of labeled precursors of protein and nucleic synthesis (14C-methionine and 3H-thymidine). The effects of acetylcholine and adrenaline, cAMP and cGMP on the intensity of 3H-thymidine incorporation into mouse B lymphocytes and on the amount of the cells entering mitosis were examined. It was shown that acetylcholine is capable of stimulating whereas adrenaline of inhibitin B lymphocyte entry into the stage of DNA synthesis and egress of these cells from the stage of DNA synthesis to the stage of mitosis. Adrenaline was found to have a reciprocal action. The acetylcholine effect could be mimetized by exogenous cGMP, that of adrenaline by cAMP. Stimulation of the G1/S transition was mediated by intracellular calcium ions but did not depend on exocellular calcium.     

Diagnosis of Aging. Report II. Age Dynamics of Correlation between the Biological Markers of Aging

The correlation analysis of the relationship between the biological age markers in three age groups revealed alterations in the number and rate of correlations up to the inversion of these relations in some cases. As a whole, the observed changes can be characterized as a rearrangement at the regulatory interactions with an increase at the strain of the functioning of the body organs and systems at the middle age and an alteration in the coordination of the body system functioning at the elderly age. The ways of the optimization of the standard methods for the biological age measurement are discussed with regard to these changes.     

First Philippine record of the parasitoid,Comperiella sp. (Hymenoptera: Encyrtidae): a potential biocontrol agent against Aspidiotus rigidus (Hemiptera: Diaspididae)

The encyrtid genus Comperiella Howard has so far not been reported in the Philippines, where there is currently an outbreak of the coconut scale insect Aspidiotus rigidus Reyne particularly in the southern parts of the island of Luzon and in some areas in Mindanao. Among Comperiella species, only C. unifasciata Ishii has been reported as a parasitoid of A. rigidus. We report not only new sightings of this parasitoid genus in the Philippines from surveys conducted in parts of the provinces of Laguna and Batangas, but also the discovery of a possibly new species that, like C. unifasciata, has been found to parasitize A. rigidus at a high rate. These findings have presented a potential of biological control against the coconut scale insect problem that has threatened the coconut industry in the country.     

DNA-Protein Complex in Circular DNA from Phage ϕ29

THE DNA of the B. subtilis phage ?29 has been described as unpermuted linear duplex molecules¹ of molecular weight 11 × 10⁶, but the formation of circular molecules has also been indicated, suggesting the existence of cohesive ends^1,2.     

Regulation of isoproterenol-induced salivary gland hyperplasia in young and old mice by substances affecting the serotonin- and dopaminergic systems

Isoproterenol-induced hyperplastic reaction has demonstrated decreased proliferative potency of salivary gland tissue in adult mice. Activation of serotoninergic mechanisms of lymphoid regulation by serotonin administration also decreased salivary gland hyperplastic reaction, predominantly in young mice. Dopamine administration enhanced the reaction in adult mice, it reaching the level observed in young animals. The number of spleen activated low density lymphocytes decreased in the case of serotonin-induced inhibition of hyperplastic reaction to isoproterenol and increased in the case of reaction stimulation. These lymphocytes have been previously shown to regulate salivary gland tissue proliferation in response to isoproterenol.     

A Decrease in the Rate of Human Aging in the 20th Century and its Potential Causes

Biophysics - Abstract—Since the middle of the 20th century, there has been a decrease in the rate of aging for developed countries with a maximum for ages 60–85 years. The calculation...     

Comparative Analysis of Methods for Estimating the Rate of Population Aging

Biophysics - The essence of aging is a decline in total vitality with age, being basic personal characteristics of human potential. Viability ( $${v}$$ ) is defined as the probability of surviving...     

Cyclic nucleotides and calcium ions in the activation of B-lymphocyte movement in mice by an anti-immunoglobulin serum

It was shown that B lymphocyte motility activated by anti-immunoglobulin serum may be abrogated in a Na+-deficient medium and in a 10(-5)M trifluoperazine-containing medium but not in a Ca2+-deficient medium. The tetracycline fluorescence test demonstrated Ca2+ efflux from isolated B lymphocyte mitochondria due to Na+ exposure. The radioimmunoassay demonstrated the cGMP level to rise after exposure to anti-immunoglobulin serum. The Na+-dependent Ca2+ efflux from the mitochondria might be the main mechanism in anti-immunoglobulin serum activation of B lymphocytes and in the cGMP level rising.