Blockade of deoxyribonucleic acid synthesis by deuterium oxide

Interference with deoxyribonucleic acid replication need not be a primary mechanism in the blockade of cell division by deuterium oxide, but current hypotheses on the molecular basis of the blockade do suggest that such interference might take place under appropriate conditions. Autoradiographic experiments support the suggestion, for whereas normal sea urchin eggs incorporate H(3)-thymidine into deoxyribonucleic acid from almost the beginning of development, cells immersed in deuterium-enriched media do not. Blockade of mitosis and inhibition of thymidine incorporation are simultaneously relieved when the eggs are returned to normal water.     

Pseudomonas aeruginosa: growth in distilled water from hospitals

Pseudomonas aeruginosa can grow relatively fast in distilled water obtained in hospitals and achieve high cell contaminations which remain stable for long periods of time. Cells grown in distilled water react quite differently to chemical and physical stresses than cells grown in standard laboratory culture media.     

Barley Stripe Mosaic Virus (<Emphasis Type="Italic">Virgaviridae,Hordeivirus</Emphasis>) As Etiological Agent of Maize Chlorotic Stripe Disease

The presence of barley stripe mosaic virus (BSMV) (Virgaviridae, Hordeivirus) infection background in maize (Zea mays) crops in the territory of Primorsky krai was demonstrated. Field data and model experiments established that BSMV causes the disease formerly called “maize chlorotic stripe disease” with the following symptoms: general chlorosis of leaves at the early stages of plant development, the emergence of pale yellow, nearly white strikes along the midrib throughout the length of the leaf, and loss of infected plants to the stage of pulling (12–25%; average value of 17.1%) and elongation with the absence of severe death in the later stages. The coefficient of harmfulness for BSMV (37.1%) was determined in the study. We concluded that planned monitoring in relation to BSMV is required for planting maize.     

Role of Na+/H+ exchange by interferon-gamma in enhanced expression of JE and I-A beta genes

The rapid transductional sequences initiated by interferon-gamma (IFN-gamma) on binding to its receptor regulate functional and genomic responses in many cells but are not well defined. Induction of macrophage activation is an example of such functional and genomic changes in response to IFN-gamma. Addition of IFN-gamma to murine macrophages, at activating concentrations, produced rapid (within 60 seconds) alkalinization of the cytosol and a concomitant, rapid influx of 22Na+. Amiloride inhibited the ion fluxes and the accumulation of specific messenger RNA for two genes induced by IFN-gamma (the early gene JE and the beta chain of the class II major histocompatibility complex gene I-A). The data indicate that IFN-gamma initiates rapid exchange of Na+ and H+ by means of the Na+/H+ antiporter and that these amiloride-sensitive ion fluxes are important to some of the genomic effects of IFN-gamma.     

Ultraviolet spectrometer observations of neptune and triton

Results from the occultation of the sun by Neptune imply a temperature of 750 +/- 150 kelvins in the upper levels of the atmosphere (composed mostly of atomic and molecular hydrogen) and define the distributions of methane, acetylene, and ethane at lower levels. The ultraviolet spectrum of the sunlit atmosphere of Neptune resembles the spectra of the Jupiter, Saturn, and Uranus atmospheres in that it is dominated by the emissions of H Lyman alpha (340 +/- 20 rayleighs) and molecular hydrogen. The extreme ultraviolet emissions in the range from 800 to 1100 angstroms at the four planets visited by Voyager scale approximately as the inverse square of their heliocentric distances. Weak auroral emissions have been tentatively identified on the night side of Neptune. Airglow and occultation observations of Triton's atmosphere show that it is composed mainly of molecular nitrogen, with a trace of methane near the surface. The temperature of Triton's upper atmosphere is 95 +/- 5 kelvins, and the surface pressure is roughly 14 microbars.