Androgen dynamics in vitro in the normal and hyperplastic human prostate gland

The dynamics of uptake and metabolism in vitro of androgens by normal and hyperplastic human prostate glands was studied by means of a new experimental design proposed by Gurpide & Welch (1969). Prostate slices were perfused with a medium containing [(3)H]testosterone and [(14)C]androstenedione, or 5alpha-dihydro-[(3)H]testosterone and [(14)C]testosterone. The entry into the slices, the irreversible metabolism, the conversion between the compounds and the tissue retention or ;uptake' of the steroids were measured at the steady state. A similar portion of the three androgens entered the tissue and was irreversibly metabolized. Conversion of testosterone into 5alpha-dihydrotestosterone was much greater than the interconversion of testosterone and androstenedione. The prostate slices retained 5alpha-dihydrotestosterone at a concentration three times that in the medium, whereas testosterone and androstenedione were retained to a smaller extent. At a steroid concentration of 0.11mumol/l in the medium, the various parameters did not differ significantly in experiments performed with slices from normal and hyperplastic glands. When the steroid concentration in the medium was increased tenfold, however, a difference between normal and hyperplastic glands was evident. The normal glands increased the uptake and metabolism proportionally to the elevation of the steroid concentration in the medium. In the hyperplastic glands the entry and metabolism lagged behind the increase in steroid supply, whereas the tissue uptake became disproportionately high. The possible causes of this finding are discussed.     

Composition of root exometabolites of the symbiotically effective pea cultivar triumph and its parental forms

The qualitative and quantitative composition of low-molecular exometabolites in roots of pea (Pisum sativum L.) was studied with a cultivar Triumph and its parental forms (a symbiotically effective variety k-8274 and a modern highly productive cv. Classic). A relationship between root exudation and the ability of cultivars to establish symbiosis was analyzed. In the early stages of plant growth, the roots of cv. Triumph exhibited low exudation of organic acids, sugars, and amino acids. The quantitative composition of organic acids in the root exudates of cv. Triumph was close to that of cv. k-8274, whereas the composition of sugars and amino acids was similar to that of cv. Classic. In the field experiment, the effect of inoculation with a mixture of rhizobium strains and mycorrhizal fungus on plant growth was more evident in cv. Triumph than in cvs. Classic and k-8274. The results suggest that the high symbiotic potential of cv. Triumph is related to exudation of pyruvic and succinic acids that were the major components of root exometabolites both in Triumph and k-8274 cultivars.     

Upregulation of Neuronal Nitric Oxide Synthase in in Vitro Stellate Astrocytes and in Vivo Reactive Astrocytes After Electrically Induced Status Epilepticus

Neuronal nitric oxide synthase (nNOS) is a constitutively expressed and calcium-dependent enzyme. Despite predominantly expressed in neurons, nNOS has been also found in astrocytes, although at lower expression levels. We have studied the regulation of nNOS expression in cultured rat astrocytes from cortex and spinal cord by Western blotting and immunocytochemistry. nNOS was not detectable in cultured astrocytes grown in serum-containing medium (SCM), but was highly expressed after serum deprivation. Accordingly, calcium-dependent NOS activity and both intracellular nitrite levels and nitrotyrosine immunoreactivity after glutamate stimulation were higher in serum-deprived astrocytes than in cells grown in SCM. Serum deprivation induced a modification of astrocytes morphology, from flat to stellate. nNOS upregulation was also observed in reactive astrocytes of rat hippocampi after electrically induced status epilepticus, as demonstrated by double-labeling experiments. Thus, nNOS upregulation occurs in both in vitro stellate and in vivo reactive astrocytes, suggesting a possible involvement of glial nNOS in neurological diseases characterized by reactive gliosis.     

Thymine- and thymidine-dependence of Yersinia pestis mutants with altered thymidylate synthetase

Thymine- and thymidine-dependent mutants of Y. pestis strain EV-76 have been isolated and characterized. Obtaining Y. pestis thymine-dependent mutants in trimethoprim-containing media with full nutritional value in the presence of thymine and thymidine and the capacity of natural strains from the foci of infection in Transcaucasia and Mongolia to grow in such media indicate that Y. pestis has gene tpp controlling thymidine phosphorylase, but this enzyme is strongly suppressed under normal conditions. The capacity for its suppression under definite conditions and the degree of the activation of thymidine phosphorylase determine the realization of Thy and Thyd phenotypes in Y. pestis mutants under study, though both types of these mutants have a mutation damage of gene thy A coding the synthesis of thymidylate synthetase.     

Nighttime Sugar Starvation Orchestrates Gibberellin Biosynthesis and Plant Growth in Arabidopsis

A plant’s eventual size depends on the integration of its genetic program with environmental cues, which vary on a daily basis. Both efficient carbon metabolism and the plant hormone gibberellin are required to guarantee optimal plant growth. Yet, little is known about the interplay between carbon metabolism and gibberellins that modulates plant growth. Here, we show that sugar starvation in Arabidopsis thaliana arising from inefficient starch metabolism at night strongly reduces the expression of ent-kaurene synthase, a key regulatory enzyme for gibberellin synthesis, the following day. Our results demonstrate that plants integrate the efficiency of photosynthesis over a period of days, which is transduced into a daily rate of gibberellin biosynthesis. This enables a plant to grow to a size that is compatible with its environment.     

Estimating the Abundance of Bottom Fish at the Shelf and Continental Slope in Northern Primorye

Journal of Ichthyology - Based on materials from bottom trawl surveys of 2009–2015, biomass and abundance of bottom fish of the Sea of ​​Japan between the Povorotny and Zolotoy...