Ultrastructural and cytochemical analysis of Na+, K+, ATPase and H+, K+, ATPase in parietal cells of gastric mucosa in the rabbit

Summary Rabbit gastric secretion has the physiological peculiarity of being continuous and uninfluenced by food intake. In this respect, ultrastructural analysis of rabbit parietal cells has revealed morphofunctional features situated between states of rest and very active acid secretion. Our cytochemical study shows that Mg²⁺ ATPase and ADPase activities vary from cell to cell and can even be totally absent. These activities concern either microcanaliculi or laterobasal folds or both, but never tubulovesicles. Application of the technique of Mayahara to K⁺ pNPP, associated or not with inhibitors (ouabain, vanadate, N-ethyl-maleimide, sodium fluoride), enabled us to confirm the coexistence of H⁺, K⁺, ATPase and Na⁺, K⁺, ATPase activities in the rabbit and to determine that these activities concern basolateral folds, microcanaliculi, hyaloplasm and tubulovesicles. The global activity of K⁺, pNPPase varied considerably in intensity. The results of using inhibitors suggest that proton transport ceases completely in certain cells. The signs of functional alternation found in this study are in agreement with physiological data relative to this animal.     

Transcriptomic biomarkers of the response of hospitalized geriatric patients with infectious diseases

Background  

Infectious diseases are significant causes of morbidity and mortality among elderly populations. However, the relationship between oxidative stress, immune function and inflammatory response in acute phase of the infectious disease is poorly understood.     

Study of the orientation of DNA molecules in an electrical field by anisotropy of electrical conductivity of their aqueous solution

Electro-conductive anisotropy of DNA solution caused by the molecular orientation in the external electric field was investigated. The dependence of a relative change of the conductivity of aqueous-salt DNA solution on the electric field in the amplitude range 0-700 V/cm and in the frequency range 100 Hz-10 kHz was studied. It was pointed out that the field thermal effect is an overcoming factor when the orientation of DNA molecules is investigated by field-free relaxation.     

Physicochemical properties of the human lymphocyte mitogenic factor induced by phytohemagglutinin]

Some physical and chemical properties of the mitogenic factor (MF) produced in vitro by PHA-stimulated human lymphocytes were investigated. Treatment of the culture medium with proteases proved to decrease the MF activity sharply. The MF was found to have an elution pattern in Sephadex and Bio-gel gels similar to proteins with the molecular weight of 20 000--30 000 daltons (peak--25 000). In experiments with the MF fractionation by disc-electrophoresis on 5% polyacylamide gel the MF formed a few discrete peaks in the fractions corresponding to the mobility of alpha1- and alpha2-globulins and transferrin. In isoelectric focusing the MF formed 3 fractions in the pH range of 4.5--8.3. Functional heterogeneity of the MF is suggested.     

Effect of hyperoxia on the rate of restoration of blood composition after blood loss]

Regeneration of the peripheral red blood was considerably retarded in the anemic rabbits (blood letting of 2% of body weight) after a 5-hour exposure to the hyperoxiconditions (98% of oxygen in the inhaled air, 2 ata).     

Study of the dynamics of a plasma current sheath in the KPF-4 Phoenix plasma-focus facility

The engineering characteristics of the KPF-4 Phoenix megajoule Mather-type plasma focus facility constructed at the Sukhumi Physicotechnical Institute are described. Results from preliminary studies of the plasma dynamics at a capacitive-storage energy of up to 700 kJ are discussed. Future experiments in KPF-4 will be oriented at technological applications and will complement the studies carried out in the 2.8-MJ Filippovtype PF-3 plasma focus facility at the Nuclear Fusion Institute of the Russian Research Centre Kurchatov Institute.