[Cytomegalovirus infection in melanoma patients]. / Tsitomegalovirusnaia infektsiia u bol'nykh melanomoi.

The occurrence of active cytomegalovirus (CMV) infection in 30 patients with skin melanoma, aged 18-76 years, was studied with the enzyme immunoassay, the direct immunofluorescence test and the polymerase chain reaction. The patients were divided into two groups: group I consisted of 20 patients examined in a month after radical surgical treatment, group II consisted of 10 patients at the stage of the process generalization. For comparison, group III was formed consisting of 89 patients with diagnosed secondary immunodeficiency and clinical manifestations of CMV infection. The control group included 80 donors. The study showed that in group II the occurrence of active CMV infection was 4 times higher than in group I and practically coincided with the results registered in group III. In the evaluation of the immune status of the members of group II the most profound changes were revealed in T-cell mediated immunity and in phagocytic immunity; the adequate production of tumor necrosis factor alpha and interleukin 1beta was absent, which created prerequisites for the activation of CMV and the aggravation of the prognosis.

[Pharmacological analysis of the role of central alpha-2 adrenergic and imidazoline receptors in mechanism of the hypotensive effect of clonidine in rats]. / Farmakologicheskii analiz roli tsentral'nykh al'fa2-adrenergicheskikh i imidazolinovykh retseptorov v mekhanizme gipotenzivnogo deistviia klonidina u krys.

The role of alpha 2-adrenergic and imidazoline receptors in the hemodynamic response to clonidine (manifested by reduced arterial pressure, heart rate, and renal blood flow rate) was studied by injecting their antagonists with different affinity (yohimbine and idazoxan) into narcotized Sprague--Dawley rats. The local introduction (microinjection into rostral ventrolateral medulla) and systemic administration (intraperitoneal injection) of the drugs showed that the hemodynamic effect of clonidine is mediated predominantly by the central alpha 2-adrenergic receptors, rather than by the imidazoline receptors.

[Changes in the local cerebral blood flow during the microdialysis administration of vasoactive substances]. / Izuchenie izmenenii lokal'nogo mozgovogo krovotoka pri mikrodializnom vvedenii vazoaktivnykh veshchestv.

The authors suggest the construction of a cannula for microdialysis combined with a light guide of a laser doppler flowmeter. Such a design allows monitoring of blood flow intensity in the environment of the microdialyzer. An advantage of local administration of vasoactive agents is that they cause no effect on systemic arterial pressure. When administered locally, sodium nitroprusside increased whereas the inhibitor NO-synthase reduced blood flow intensity. No changes were detected in the local blood flow in administration of phenylephrine and nitroglycerin through the dialyzer. Tetrodoxin insignificantly reduced the blood flow. The existence of a diffusion barrier for some agents as well as the long period of time needed for attaining the state of equilibrium after beginning perfusion of the solution containing the agent under test is among the disadvantages of local administration.

[Changes in the NO-dependent regulation of the local cerebral blood flow in rats during adaptation to the conditions of simulated weightlessness]. / Izmenenie NO-zavisimoi reguliatsii lokal'nogo mozgovogo krovotoka krys pri adaptatsii k usloviiam modelirovannoi nevesomosti.

The nitrogen oxide NO-dependent regulation of the cerebral blood flow was studied before and after 24-hr head-down immobilization (HDI) of intact and pre-trained rats. Training consisted in 2-hr tail-suspension each day of the 2-wk period. Blood flow was determined with the laser Doppler flowmetry following local injection of a NO synthesis blocker (L-NAME), and NO (sodium nitroprusside). Neither HDI nor pre-training per se influenced NO tonic production in the cortex of large hemispheres and cerebellum. However, in pre-trained animals HDI resulted in a significant blood flow response to the local blockade of NO synthesis in the cerebellum. None of the animals changed the reaction of the blood flow to the local injection of sodium nitroprusside. The conclusion was drawn that alteration in the NO-dependent regulation of the brain blood flow in pre-trained animals could manifest of adaptation to HDI in the course of 24-hr suspension.

[The dynamics of the central and peripheral blood circulation in waking rats in the first 24 hours of head-down tilt hypokinesia (the role of training)]. / Dinamika tsentral'nogo i perifericheskogo krovoobrashcheniia u bodrstvuiushchikh krys v pervye sutki antiortostaticheskoi gipokinezii (rol' trenirovki).

The male Wistar rats were used to study an effect of preliminary antiorthostatic training on the systemic and regional hemodynamics during 24-hour head down tilting (HDT). It is indicated that the main parameters of the systemic hemodynamics (arterial blood pressure, heart rate, central venous pressure, total peripheric resistance, systemic veins) in trained animals were changed to a lesser extent as opposed to the controls. The dynamics of the mean pressure of blood filling--a parameter responsible for the state of systemic veins of the body--was group different. The blood flow changes in the organs and tissues were tended to be the same, however these changes were less severe in the trained rats. Thus pretraining of the rats, not changing the general trend of the shifts in the recorded values, decreases the severity of their variations.

[Systemic and regional hemodynamics in conscious rats during 24-hour antiorthostatic posture]. / Sistemnaia i regionarnaia gemodinamika u bodrstvuiushchikh krys v usloviiakh 24-chasovogo antiortostaza.

The systemic and regional hemodynamics during antiorthostatic hypokinesia were studied in male Wistar rats using the radioactive microsphere technique. The animals were hanged up by the tail with the head tilted down (30 degrees) and were able to exercise using only front limbs. Twenty four hours long exposure to antiorthostasis induced significant changes in systemic hemodynamics as well as in regional blood flow in skeletal muscles, spleen, liver and pancreas. Antiorthostasis induced blood flow changes in lungs, heart and brain were less pronounced.

[Study of mechanical oscillations of guinea pig atrial myocardium during cooling]. / Issledovanie mekhanicheskikh ostsilliatsii v miokarde predserdiia morskoi svinki pri okhlazhdenii.

Spontaneous mechanical oscillations--period damping oscillations of isometric tension, that occur immediately after discontinuance of the preparation contraction, induced by an external stimulation were studied in the guinea-pig auricle within the temperature range 17-7 degrees C. The mechanical oscillations were established to appear at 17 degrees C. With temperature decrease the amplitude of the oscillations rose and reached maximum at 9 degrees C and then fell down. The mechanical oscillations were not attended by oscillations of the membrane potential. The amplitude and magnitude of mechanical oscillations increased with Ca2+ concentration elevation in the medium and dropped down with its diminution. Addition of caffeine (10 mM) or KCI (20 mM) to the Tirode solution resulted in complete suppression of mechanical oscillations in the presence of the drastically decreased rhythmic contractions. It is assumed that the appearance of mechanical oscillations may be caused by the increased content of Ca2+ ions in the myoplasma of myocytes. This increase is consequent on the slowing down of the sequestering ability of sarcoplasmatic reticulum (SR) on cooling. It is suggested that SR may be a greater of mechanical oscillations.

[Piezoeffect, baseline conductivity and filtration coefficients of lipid bilayer membrane]. / P'ezoéffekt, fonovaia provodimost' i fil'tratsionnye koéffitsinety bisloinykh lipidnykh membran.

A piezoeffect in bilayer lipid membranes (BLM), i.e. a generation of alternate electrical current y through a membrane under alternate pressure gradient in the absence of constant transmembrane potential is investigated. It is shown that y is not connected with the membrane deformations, it is generated with electroosmotic flow of K+ ions, its amplitude increases with a rise of BLM phonic conductance and is probably connected with defects in BLM structure. The value of the filtration coefficient Lp is estimated.