Effect of the Peptide Calcium Channel Blocker ω-hexatoxin-Hv1a on Cell Death during Ischemia/Reperfusion in vitro.

Apoptosis and necrosis during reperfusion after ischemia are key mechanisms at the cellular level leading to damage. The development of pathological conditions is preceded by intracellular calcium ion overload both at the stage of ischemia and at the stage of reperfusion. In this regard, one of the strategies aimed at reducing damage during ischemia/reperfusion is associated with the use of calcium channel blockers. The aim of the study was to study the effect of a peptide toxin, a calcium channel blocker ω-hexatoxin-Hv1a, on different types of epithelial cell death during in vitro reconstruction of ischemia/reperfusion conditions characteristic of organ transplantation. Materials and Methods: In this study, we used CHO-K1 epithelial cell culture. Changes in apoptosis, necrosis, cell index, and calcium ion concentration were assessed when modeling ischemia/reperfusion processes in vitro with the addition of a calcium channel blocker toxin. Ischemic and reperfusion injury was achieved by oxygen and nutrient deprivation followed by reperfusion in a complete nutrient medium. The measurements were performed using a multimodal plate reader-fluorimeter. Results: An increase in apoptosis, necrosis, and the concentration of calcium ions was recorded when modeling ischemia/reperfusion processes. A decrease in the level of apoptosis and necrosis, as well as the concentration of calcium ions to a physiological level or a level close to physiological, was noted when the toxin was added at a concentration of 50 nM at the reperfusion stage. The cell index showed a faster restoration in the presence of the toxin. Conclusion: The experimental data confirm the hypothesis of a beneficial effect of peptide calcium channel blockers on the state of epithelial cells during reperfusion after ischemia and can be considered for further study as a strategy for organ adaptation before reperfusion.

Detuning effects in Brillouin ring microresonator laser.

Brillouin lasers, with their unique properties, offer an intriguing solution for many applications, yet bringing their performance to integrated platforms has remained questionable. We present a theoretical framework to describe Brillouin lasing in integrated ring microcavities. Specifically, a general case of a mismatch between the Brillouin shift and the microresonator inter-mode spacing is considered. We show that although the lasing threshold is increased with the frequency detuning, a significant enhancement of the laser power in comparison with the pure resonant interaction could be achieved. Moreover, there is an optimal pump frequency detuning from the resonant mode frequency, when the effect is most pronounced. An increase of the Brillouin threshold with the pump frequency detuning is accompanied by narrowing the pump frequency range available for lasing. Importantly, at the optimal value of the pump frequency detuning when the Brillouin signal is maximal, Brillouin signal noise level is minimal. Analytical results obtained in the steady-state approach are in quantitative agreement with the results of numerical simulations.

Role of oxidative stress in mechanisms of premature aging in shift labor workers.

There have been examined 90 practically healthy male-shift-workers 21-58 aged and 21-60 aged (average age 41.4 +/- 1.4 and 48.6 +/- 1.3) who worked for a long period of time in the North on shift at the enterprises of JS "Yamburggasdobycha" at the moment of examination. It was revealed a high content of glycosaminoglycans (GAG) in blood serum (2.20 +/- 0.12 mmol/l), accumulation of LPO products (3.45 +/- 0.18 nmol MDA/ml) against the background of decreased glutationreductase activity (0.38 +/- 0.04 mkmol/l hour). Level of total cholesterol was increased at standard content of HDL (6.1+0.2). It can be concluded that definition of GAG and MDA in blood is one of the significant criteria, reflecting adaptative tension and premature aging of shift-workers.

Estimation of functional state and labour efficiency of shift workers in conditions of the Far North.

OBJECTIVES: Shift work is an expeditionary method, and it has become quite common for the maintenance of industrial process in the Far North. In spite of good equipment and a high professional standard of the medical personnel in the majority of northern enterprises, the level of morbidity tends to increase. The aims of our work were to evaluate the psychophysiological alterations in shift-workers during transit labour. METHODS: Shift workers of "Gazprom" Public Corporation were examined in conditions of the Far North using psychological and physiological methods. RESULTS: The morbidity of shift workers is higher than that of non-transit workers working in the same industries. Distinct changes of the functional condition of the cardiorespiratory system were discovered. While comparing shift workers of the Far North with workers of the Central regions of Russia we discovered an essential prevalence of isolated systolic hypertension (44.6%) in the first group. It is established that an increase of anxiety level (situational and personal) is much more common in persons having haemodynamic signs of hypertension. For workers in intraregional shift work metabolic exchange disorders, and for workers in inter-regional shift disorders of immune resistance are typical. CONCLUSIONS: Our results have shown that shift work is accompanied by stress of regulatory and adaptable systems, a decrease of functional reserves and an increased morbidity and frequent relapses.

[The effect of calcium antagonists on the biochemical and immune status of hypertension patients]. / Vliianie antagonistov kal'tsiia na biokhimicheskii i immunnyi status u bol'nykh gipertonicheskoi bolezn'iu.

The immunological and biochemical parameters were studied in patients with Stage II hypertensive disease (HD) before and 2 months after course treatment with calcium antagonists of the dihydropyridine series (siscor and nitrepine). The metabolic mechanisms of the therapeutical action of these drugs were found to affect all specific features of the immune and biochemical status typical of hypertensives. One should identify the priority links which are unambiguously positive and the next links which rank to them, i. e. those manifested themselves in impaired adaptive processes whereby the sick body ensures protection from the disease. The priority links include reduction of hypercortisole- and insulinemia, increase in incretion of testosterone to the reference values, stabilization and sensitization of cellular membranes, decrease of beta 2-microglobulinemia, as well as moderate activation of the immune system and mechanisms of protein synthesis in the cells. The latter links comprise a drop of alpha-cholesterol (HDL) in persistent hypertriglyceridemia, additional tension of hepato- and cardiomyocytic functions, a tendency to cell aging and, partially, reversion of the established sexual hormone ratio.