Biology bulletin of the Academy of Sciences of the USSR最新文献

It was established that chronic irritation of the peripheral nerves as a result of cutting of the sciatic nerve and introduction of formalin into the central segment is accompanied by prolonged oliguria (for many months), hyponatriuresis, a change in te excretion of chlorine, calcium, and urea with the urine, as well as an intensification of the excretion of potassium and phosphates by the kidneys. It was shown that the decrease in the excretion of water, sodium, chlorine, and calcium by the kidneys in the presence of a neurodystrophic process is associated chiefly with a sharp inhibition of filtration of the primary urine in the glomeruli and partially with an intensification of their reabsorption. Hyperkaliuresis and hyperphosphaturia were due to activation of the secretory process in the kidney tubules, while the decrease in the excretion of urea was a consequence of a decrease in the filtration load of this substance and a decrease in the diffusion and secretory processes. Thus, chronic irritation of the sciatic nerve leads to a change in the functional activity of all parts of the nephron. It is important that different parts of the nephron react differently, both in degree and in nature, and this is fraught with serious consequences for the normal maintenance of an adequate response of the kidneys to a change in the water and electrolyte metabolism.

The intensity of respiration of the body fragments of the planarian after its division anteriorly and posteriorly to the pharynx was studied. After division anteriorly to the pharynx regeneration takes place. During regeneration of the anterior fragment respiration increases in the first day after the operation and at the differentiation stage. During regeneration of the posterior fragments the oxygen consumption is unchanged. Healing of the wound after division of the planarian posteriorly to the pharynx is accompanied by intensification of respiration during the first two days after the operation. Comparison of regeneration and healing of the wound in fragments of equal weight shows that in the initial stages the intensity of respiration was the same. A significant difference is found at the stage of differentiation of the regenerating worm, when the regenerating fragments have a higher intensity of respiration than fragments unable to regenerate.

A quantitative method for the anaerobic isolation of a molybdenum cofactor from two molybdenum-containing enzymes, nitrate reductase from the bacteroids of lupine nodules and xanthine oxidase from milk, is described. It was established that the cofactor consists of an aromatic component and a number of amino acid residues bound to it. The structural and catalytic function of the molybdenum cofactor in the enzyme was established.

It was established that in healthy animals the intensity of synthesis of quick-labeling RNA and also the percentage of small and medium labeled lymphocytes are substantially higher in the lymphocytes of lymph than in the lymphocytes of blood. The percentage of small blood lymphocytes doubles (from 25 to 50%) during leukosis, but is almost unchanged in lymph. For the majority of animals with leukosis, an increase of 5 to 10 times in the percentage of strongly labeled cells, including all types of lymphocytes, is characteristic.

Complex formation between spin-labeled 9-aminoacridine and DNA or polynucleotides has been studied by differential spectrophotometry and ESR. The differential spectra of the strong type 9-aminoacridine-DNA complex showed characteristic absorption bands at 270 and 290 nm, and the intensity ratio of these bands varied according to the degree of DNA denaturation. The ESR spectra of this complex were characterized by slow rotation of the radical; as the macromolecule became increasingly denatured and in the polynucleotide complex, a rapid signal appeared in the ESR spectrum. The temperature at which DNA undergoes a structural transition in the premelting region could be determined from the temperature dependence of the ESR spectral form of the dye-DNA complex. The spectral characteristics of the complexes give additional information about structural disturbances in DNA.

In order to determine the relative role of neural factors in the regulation of the activity of the eccrine glands of rats during stress, the cytological and cytochemical criteria of their activity that we used earlier (glycogen, isoelectric point of the mitochondria, ratio of light and dark secretory cells) were applied to the eccrine glands of rats with chemical sympathectomy, induced for four-week administration of guanethidine. The level of sweat secretion and the histochemistry of monamine oxidase and cholinesterases were also investigated. It is found that after 2-h immobilization stress and in the case of chemical sympathectomy, the eccrine glands of rats exhibit practically complete similarity in the level of sweat secretion and in various histochemical indices of the activity of the glands and the state of the neuromediator systems. In comparison with the control, in these glands the sweat secretion is increased, there is no glycogen, the number of light secretory cells is increased and the number of dark ones decreased, the isoelectric point of the mitochondria is shifted by a unit of the pH scale in the alkaline direction, the monamine oxidase activity of the mitochondria of the secretory cells and the myelinated nerves is sharply reduced, and the anticholinesterase of the nerves that interlace the gland disappears. In the case of immobilization stress there is an apparent functional denervation of the eccrine glands.

While the share of protein from unicellular organisms is but a small fraction of total protein production, the methods of microbiologic production appear rather promising and have been greatly developed in the last 10-15 years. The author discusses technologic methods for obtaining protein from unicellular organisms, questions of selecting the raw material and the producers used in these processes, and the fields for use of the product obtained. The range of suitable taxonomic groups of microorganisms and of substrates for these processes has lately been broadened. Attention has been focussed on the use of renewable feedstock and of industrial wastes (cellulose-containing materials, etc.). Use of the latter for microbiologic synthesis could produce enough protein to make up for the global deficit in protein. The author also discusses questions of improving, enlarging, and automating the equipment suitable for these processes.

The influence of the triterpene glycosides holothurin and cucumariaside from Holothuria grissi and Cucumaria japonica, respectively, on the parameters of the active transport of calcium ions by vesicles of the sarcoplasmic reticulum and on the permeability of liposomes formed from the total fraction of egg phospholipids was investigated. It was found that at low concentrations these substances decrease the Ca-ATPase activity without noticeably increasing the permeability of the membranes, whereas at high concentrations they cause a sharp increase in the permeability of the membranes of Ca2+ ions.

Our results and the recent literature data on the biological action of near ultraviolet light (300-380 nm) are examined in the review. Factual material is presented on the principles governing the manifestation of the following effects of near ultraviolet light in microorganisms: inactivation, delayed growth, photoreactivation, photoprotection, photoinduced sporulation (in fungi), and carotene synthesis. The mature and possible mechanisms of the effects examined are discussed.

A highly specific and readily reproducible cytochemical method for detecting DNA in nuclear structures of fixed cells has been developed. The method involves the reduction of metallic silver by aldehydes of the 2-deoxyribose of apurinic DNA from a solution of silver ammine prepared with allowance made for the requirements of the chemistry of the reaction. It was found that the method developed can be used for a quantitative analysis of DNA in animal cells.