A combined Raman lidar for low tropospheric studies

One of the main goals of laser sensing of the atmosphere was the development of techniques and facilities for remote determination of atmospheric meteorological and optical parameters. Of lidar techniques known at present the Raman-lidar technique occupies a specific place. On the one hand Raman lidar returns due to scattering on different molecular species are very simple for interpretation and for extracting the information on the atmospheric parameters sought, but, on the other hand, the performance of these techniques in a lidar facility is overburdened with some serious technical difficulties due to extremely low cross sections of Raman effect. Some results of investigations into this problem is presented which enables the construction of a combined Raman lidar capable of acquiring simultaneously the profiles of atmospheric temperature, humidity, and some optical characteristics in the ground atmospheric layer up to 1 km height. The operation of this system is briefly discussed

Reactive oxygen species in pathogenesis of atherosclerosis.

Co-author affiliations: - Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Saint Petersburg, Russia - Research Institute of Hygiene, Occupational Pathology and Human Ecology, Saint Petersburg, Russia - Koltzov Institute of Developmental Biology RAS, Moscow, Russia - Institute of Cell Biophysics RAS, Pushchino, Russia - Institute of General Pathology and Pathophysiology RAMS, Moscow, RussiaThe volume of publications on the role of reactive oxygen species (ROS) in biological processes has been increasing exponentially over the last decades. ROS in large amounts clearly have detrimental effects on cell physiology, whereas low concentrations of ROS are permanently produced in cells and play a role as signaling molecules. An imbalance in ROS production and defense mechanisms can lead to pathological vascular remodeling, atherosclerosis being among them. The aim of this review is to examine different sources of ROS from the point of view of their participation in pathogenesis of atherosclerosis and related cardiovascular risk. Among the possible sources of ROS discussed here are mitochondria, NADPH-oxidases, xanthine oxidase, peroxidases, NO-synthases, cytochrome P450, cyclooxygenases, lipoxygenases, and hemoglobin of red blood cells. A great challenge for future research is to establish interrelations, feedback and feed-forward regulation mechanisms of various sources of ROS in development of atherosclerosis and other vascular pathologies

АКТИВНЫЕ ФОРМЫ КИСЛОРОДА В КЛЕТКАХ СЕРДЕЧНО-СОСУДИСТОЙ СИСТЕМЫ

The data on toxic and signaling properties of reactive oxygen species (ROS) in the cells of blood vessels are presented in this review. High concentrations of ROS are naturally characteristic properties of so-called professional phagocytes, the cells of innate immunity, whereas in other cells, the high concentrations of ROS is a sign of oxidative stress. At the same time, low concentrations of ROS are permanently generated in almost all the cells of an organism and perform signaling functions as the secondary messengers in redoxsensitive signaling pathways. Vascular endothelium plays a very important role in maintenance of homeostasis, and as a rule, it is a target and one of the sources of ROS. According to some data, the local concentration of both exogenous, and endogenous ROS can reach 500 uM. Oxidative stress enhances a permeability of blood-tissue barriers, and ROS contributes significantly to development of pulmonary and brain pathologies in hypoxia and hyperoxia. Disturbance in endothelial permeability can be associated with the influence of reactive oxygen or nitrogen species on key metabolic enzymes, as well as on various units of signaling and effector pathways. Which agonists cause the primary disturbance of intracellular homeostasis? What are the mechanisms of modulation of the primary disturbance? What is the role of endogenous and exogenous sources of ROS in disturbance of intracellular homeostasis? These are the most important questions, on the solution of which the efficacy of diagnostics and treatment of cardiovascular diseases largely depend.В обзоре представлены данные о сигнальных и токсических свойствах активных форм кислорода (АФК) в клетках кровеносных сосудов. Высокие концентрации АФК в норме являются характерной функцией так называемых профессиональных фагоцитов – клеток врожденного иммунитета; в других клетках высокие концентрации АФК – признак оксидативного стресса. В то же время низкие концентрации АФК постоянно образуются практически во всех клетках организма и выполняют сигнальные функции в качестве вторичных посредников в редокс-чувствительных сигнальных путях. Эндотелий сосудов играет важнейшую роль в поддержании гомеостаза, он же, как правило, является мишенью и одним из источников АФК. По некоторым данным, локальная концентрация как эндогенных, так и экзогенных АФК может достигать 500 мкМ. Оксидативный стресс повышает проницаемость гематотканевых барьеров; так, АФК вносят решающий вклад в развитие патологии легких и мозга при гипероксии и гипоксии. Нарушение проницаемости эндотелия может быть связано с воздействием активных форм кислорода или азота на ключевые ферменты метаболизма, а также на различные звенья сигнальных и эффекторных путей. Какие агонисты обеспечивают первичное возмущение внутриклеточного гомеостаза, каковы механизмы модуляции первичного возмущения, какова роль эндогенных и экзогенных источников АФК в нарушении гомеостаза клеток – это важнейшие вопросы, от решения которых во многом зависит эффективность диагностики и терапии сердечно-сосудистых заболеваний

Study of the role of metalloproteinases and their inhibitors in the formation of posttoxic fibrosis and cirrhosis and the use of oxidized dextran in the experiment.

The purpose of the work is to evaluate the significance of metalloproteinases (MMPs) and their inhibitors in the formation of liver fibrosis and cirrhosis in the outcome of chronic hepatosis of mixed toxic etiology and the use of OD in the experiment.Цель работы − оценка значения металлопротеиназ (ММР) и их ингибиторов в формировании фиброза и цирроза печени в исходе хронического гепатоза смешанной токсической этиологии и применение окисленного декстрана (ОД) в эксперименте

Pathological changes of bone tissue and kidneys when implanted bone cement in experiment

Objective: to study the dynamics of morphological changes in the kidney and bone tissue after implantation of bone cement into the femoral bone experimentally. Material and methods. 90 male rats Wistar were divided into 3 groups. In group 1 (control) was carried out only cortical perforation of the diaphysis. The animals in group 2 is similar to the defect created cortical diaphysis of intraosseous bone cement was injected at a dose of 0.1 ml. Animals of group 3 were intact. Results. Methylmethacrylate monomer causes toxic damage bone and vascular endothelial maximally expressed at day 1-7, which promotes thrombus formation slows bone regeneration processes thigh tissue prolong the inflammatory response, thus providing the basis for a general toxic effect of methyl methacrylate and thrombotic complications. Toxic kidney damage with the introduction of bone cement, the most pronounced in the 1 st - 7 th day day of the experiment, caused primarily by necrosis and apoptosis of endothelial cells of the glomeruli with the development of thrombosis of capillaries, epithelial cells of the proximal tubule, and the subsequent observation period - increase of the severity of interstitial inflammation.Цель исследования: изучить динамику морфологических изменений в костной ткани и почках после имплантации костного цемента в бедренную кость в эксперименте. Материал и методы исследования. 90 крыс-самцов линии Вистар были разделены на 3 группы. В 1-й группе (контроль) выполнялась перфорация только кортикального слоя диафиза. Животным 2-й группы в аналогично созданный дефект кортикального слоя диафиза внутрикостно вводился костный цемент в дозе 0,1 мл. Животные 3-й группы были интактными. Результаты. Мономер метилметакрилата вызывает токсическое повреждение костной ткани и эндотелия сосудов, максимально выраженные на 1-7 сутки, что способствует тромбообразованию, замедляет процессы регенерации костной ткани бедра, пролонгирует воспалительную реакцию, тем самым создавая основу для общего токсического действия метилметакрилата и тромботических осложнений. Токсическое повреждение почек при введении костного цемента, максимально выраженное на 1-е - 7 сутки сутки эксперимента, обусловлено, прежде всего, некрозом и апоптозом эндотелиоцитов клубочков с развитием тромбоза капилляров, эпителиоцитов проксимальных канальцев, а в последующий период наблюдения - нарастанием выраженности интерстициального воспаления

Analysis of the correctness of retrieving the vertical atmospheric temperature distribution from lidar signals of molecular scattering at the main lidar of the Siberian Lidar Station

The methodological issues of lidar measurements of the vertical distribution of atmospheric temperature up to altitudes of 90 km are considered. The method is based on lidar measurements of the vertical profile of atmospheric molecular density using the Rayleigh scattering effect. The results obtained in the upgraded channel of the Rayleigh scattering of the 2.2-m diameter lidar based on the main mirror of the Siberian Lidar Station (SLS) are discussed. One of problems in carrying out measurements with the use of large-diameter telescopes is the giant dynamic range of lidar responses. The work with this range requires special attention both to the methodology and to the experimental technique. For solving this problem, an improved technique for the retrieval of temperature from molecular backscattering lidar signals is proposed. Numerical experiments have shown that the accuracy of the temperature profile retrieval depends on the choice of the position of the calibration point and the error in setting the temperature in it. The technique of the temperature profile retrieval, when the calibration point is chosen at the top of a sounding path, is sufficiently stable even under conditions of a giant dynamic range of lidar responses at the SLS. The comparison of the results of temperature retrieval from the real lidar responses with the satellite measurement data revealed significant discrepancies associated with the distorting instrumental and atmospheric effects on the lidar signal shape. A correction procedure based on the lidar calibration can significantly reduce measurement errors

«One Small Step for Mouse»: High CO2 Inhalation as a New Therapeutic Strategy for Parkinson’s Disease

Parkinson’s disease (PD) is a ubiquitous neurodegenerative disorder for which no effective treatment strategies are available. Existing pharmacotherapy is aimed only at correcting symptoms and slowing the progression of the disease, mainly by replenishing dopamine deficiency. It is assumed that mitochondrial dysfunction plays a key role in the pathogenesis of PD. It has been suggested that activation of specific degradation of damaged mitochondria (mitophagy) may prevent cell death. An almost exclusive way to initiate mitophagy is acidification of intracellular pH. We attempted to implement transient brain acidification using two experimental therapy strategies: forced moderate physical activity and high CO2 inhalation. The beneficial effects of CO2 supplementation on behavioral aspects were demonstrated in a rotenone-induced PD model. Mice treated with CO2 restored their exploratory behavior and total locomotor activity lost after rotenone administration. Additionally, this treatment enabled the removal of impaired coordination. We have illustrated this therapeutic strategy using histological studies of brain sections to confirm the survival of nigrostriatal areas. These findings suggest that high CO2 inhalation presumably initiates mitophagy via transient brain acidification, and can treat PD-like symptoms in a rodent rotenone model of PD

Markers and Biomarkers of Endothelium: When Something Is Rotten in the State

open access articleEndothelium is a community of endothelial cells (ECs), which line the blood and lymphatic vessels, thus forming an interface between the tissues and the blood or lympha. This strategic position of endothelium infers its indispensable functional role in controlling vasoregulation, haemostasis, and inflammation. The state of endothelium is simultaneously the cause and effect of many diseases, and this is coupled with modifications of endothelial phenotype represented by markers and with biochemical profile of blood represented by biomarkers. In this paper, we briefly review data on the functional role of endothelium, give definitions of endothelial markers and biomarkers, touch on the methodological approaches for revealing biomarkers, present an implicit role of endothelium in some toxicological mechanistic studies, and survey the role of reactive oxygen species (ROS) in modulation of endothelial status

Photon counting system with automated detection and selection of photodetector discrimination thresholds

The paper considers a block diagram of a photodetection system based on a new version of the four-channel photon counter "PHCOUNT-4" used for precision lidar measurements of atmospheric temperature. The results of using the new capabilities of the analog part of the photon counting system, which makes it possible to automatically record the amplitude distribution of single-electron pulses of each of the photodetectors installed in the channels and determine the optimal discrimination threshold, are described. It is shown that setting the optimal discrimination thresholds makes it possible to achieve a small spread in the end-to-end quantum efficiency of each of the channel