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Biomedical subjects

A V Tkachev

Publications and source records attributed to A V Tkachev.

At least 19 recordsLinked to original sources
PubMed2005

[Hypophysis--thyroid gland--gonads in boys of the pubertate period in south areas of Archangelsk region].

The hormonal level dynamics of hypophysis, thyroid gland and sex steroids was analyzed in respect to the puberty. Concentrations of gonadotropins and sex streroids were increased whereas concentrations of thyroid hormones was decreased. The amplitude of hypophysis and thyroid hormones were narrowed whereas the range of sex steroids was extended during the puberty. In early stages of puberty, the interhormonal correlations existed on some levels (hypophysis or peripheral gland), but in late stage the intersystem and polyhormonal relations were formed. Thyroid hormones play a leading role in sexual maturity regulation. The sexual maturity is prolonged, the variance of sexual stages being quite wide. The range of gonadotropin shifted to the left side in comparison with children in moderate latitudes.

Adolescent↗
PubMed2004

[Specificity of metabolic processes observed in the glucose tolerance test in residents of the European North].

The reserve potentialities of metabolism processes and the specificity of the functioning in the course of glucose-tolerance test made in virtually healthy residence of the European North were studied with respect to body weight. A slowed utilization of glucose, triglycerides and of free fatty acids due to an intensified insulin concentration was detected, which essentially affects, in persons with excessive weight, the nature of the mentioned changes and belongs to the risk category of diabetes mellitus and ischemic heart disease.

Adult↗
PubMed2002

[Efficiency of the use of peppermint (Mentha piperita L) essential oil inhalations in the combined multi-drug therapy for pulmonary tuberculosis].

The essential oil of peppermint (Mentha piperita L.) has been found to have an in vitro pronounced and equal antimycobacterial effect in doses of 300 and 600 micrograms/ml, respectively. The use of its inhalations (upon 20-min heat evaporation into the room atmosphere for 2 months) as a supplement to combined multidrug therapy for pulmonary tuberculosis has indicated their significantly high positive effect in terms of abacillation (by 26.8 and 58.5% with doses of 0.01 and 0.005 ml/m3, respectively). This was followed by earlier positive X-ray changes in the lung and by attenuation of the intoxication syndrome. The findings suggest that peppermint essential oil may be used in combined multidrug therapy in patients with disseminated and infiltrative pulmonary tuberculosis.

Administration, Inhalation↗
PubMed2002

[Serum phospholipids and processes of cholesterol esterification in the European North].

Lipid profile was studied in blood serum of 146 European northerns (trans-polar Nenets Autonomous district and Archangelsk). Monolayer chromatography was used to determine sphingomyelin (SP), phosphatidyl ethanolamine, phosphatidylcholine (PC), lisophosphatidylcholine, glycerophosphatides and phosphatide acides. The northerns were found to have very low concentrations of blood PC. At the same time, the NAD population have a little higher SP which may play an adaptive role in terms of the cell membrane function. The transpolar natives appear to possess an adaptive mechanism of increasing total cholesterol and reducing cholesterol of high-density lipoproteins, and activation of cholesterol esterification resulting in decrease in the free cholesterol fraction in serum.

Adaptation, Physiological↗
PubMed2000

Chemical composition of lipophylic compounds from the body surface of unfed adult Ixodes persulcatus ticks (Acari: Ixodidae).

Chemical compositions of ethereal extracts of the body surface of unfed male and female Ixodes persulcatus ticks (Acari: Ixodidae) were studied by gas chromatography using mass-spectrometric detection. More than 100 different organic compounds were detected. The predominant components were saturated fatty hydrocarbons, saturated and unsaturated fatty acids, aldehydes, squalene, cholesterol and cholesterol derivatives. A number of compounds found in I. persulcatus are known as components of pheromones or constituents of dermal gland secretions in tick species of the genus Amblyomma: nonanoic acid, saturated fatty acids having from 14 to 16 carbons, and squalene. Saturated fatty aldehydes have not been reported previously as body surface components of hard ticks. Substituted phenols were not found in the extracts, although they are known as common components of sex and attraction-aggregation-attachment pheromones in Amblyomma ticks. With a few exceptions (henicosanal, 2,4-holestadiene and two unidentified cholesterol derivatives), there was no marked difference in composition of surface components between male and female I. persulcatus. The possible role of the different chemical groups in communication between I. persulcatus ticks is discussed.

Aldehydes↗
PubMed1994

Susceptibility of the taiga tick Ixodes persulcatus Schulze to pyrethroids.

The susceptibility of the taiga tick Ixodes persulcatus Schulze to 15 pyrethroids has been evaluated. The knockdown time after exposure of ticks to pyrethroids tested was quite similar. It was revealed that the lethal doses of type I pyrethroids (permethrin-like) induced the rapid attachment of ticks to host. In contrast, the fatal poisoning with type II pyrethroids (alpha-CN-pyrethroids) made the ticks unable to attach completely. Possible mechanisms of the acceleration and the prevention of attachment are discussed.

Animals↗
PubMed1993

Blood lipid parameters in participants of the Soviet-American "Bering Bridge" expedition.

Metabolic indices were studied in an expedition team consisting of Soviet and U.S. Caucasian and indigenous members. Lipid metabolism was substantially changed during this extended ski expedition, with similar trends among all participants. The most pronounced changes occurred at the beginning of the expedition with a simultaneous change in the lipid protein concentration in very low density lipoprotein (VLDL) and low density lipoprotein (LDL) cholesterol, demonstrating an activation of lipid metabolism. The HDL cholesterol level had the highest level at the third stage of the expedition. Indigenous members showed a relatively greater increase in high density lipoprotein cholesterol (HDL) compared to the Caucasians, suggesting innate differences in adaptability to cold and exertion.

Adult↗
PubMed1992

[Various indicators of the hormonal profile in patients with neuroses after psychopharmacotherapy and functional test with sinacten].

Studies of adenohypophyseal hormones, cortisol, T3, T4, thyroxine-binding globulin, testosterone, progesterone and estradiol in 90 neurotic men, treated or not with amitriptyline and benzodiazepines, allowed a conclusion that in the majority of them, endocrine functions were activated. 11 healthy men and 11 male patients underwent the three-day test with sinacten-depot (1 mg intramuscularly). The functional test data were compared over time by the methods of nonparametric statistics. The patients manifested a decrease of reserve potentialities of the pituitary-adrenal system, redistribution of the fractions of thyroid hormones, gonadotropins, the progesterone/estradiol ratio, a rise of prolactin and testosterone secretion. The drugs were found to improve the functioning of the pituitary-adrenal system. However, they did not contribute much to the positive changes in the pituitary-thyroid and other systems.

Adrenal Cortex Hormones↗
PubMed1991

[Kordaron and functional disorders of the thyroid gland].

The paper presents a brief review of literature data on cordaron action on thyroid function under a prolonged schedule of its use, and a description of 4 cases of thyrotoxicosis developed by males after 2-10 years of cordaron maintenance for paroxysms of cardiac fibrillation in a dose of 200-600 mg. Probability of thyrotoxicosis necessitates an assessment of thyroid function when planning long-term treatment with cordaron.

Adult↗
PubMed1991

Endocrine status and plasma lipids in inhabitants of the northern European part of the USSR.

Inhabitants of the northern districts of the Archangelsk Region of the USSR (Nenets and natives) were examined. Hormones of the hypophysis-adrenal cortex-thyroid gland system as well as the metabolites of lipid exchange were measured during the year. Higher mean levels of TSH and T3 were found in Nenets compared to natives. Activation of the hypophysis-thyroid gland system was demonstrated in the winter period compared to the summer one. Metabolites involved in lipid exchange transport in blood remained stable in Nenets, while natives showed dynamics of the lipid exchange metabolites related to the different seasons of the year.

Adult↗
PubMed1991

Dynamics of hormone and metabolic state in polar inhabitants depend on daylight duration.

Fluctuations in the level of TSH, T3, T4 and total cholesterol were determined in male aborigines and native polar inhabitants in different photoperiods of the year. It was found that a rise of serum TSH and T3 and a reduction of the thyroxine level and total cholesterol occurred in both population groups with the lengthening of daylight duration. However, the amplitude of annual fluctuations in the studied variables was different. There was a significant correlation between TSH, T4 and T3 levels and daylight duration. The photoperiodical contrasts of the polar regions are probably important in the formation of the annual fluctuations of hormone levels of the hypophysis-thyroid gland system and total cholesterol.

Adult↗
PubMed1990

[Sucralfate: the agent of choice in the treatment of peptic ulcer?].

As many as 72 patients with erosive and ulcerous injuries to the stomach and duodenum were examined for the clinical efficacy of antepsin (sucralfate). Of these patients, 42 were with duodenal ulcer, 10 with gastric ulcer and 20 with erosive gastroduodenitis). Antepsin exerted a beneficial effect on the painful syndrome and on ulcer and erosion healing. The coefficient of the therapeutic efficacy of antepsin in duodenal ulcer patients turned out to be equal to 2.67 that of gastric ulcer to 2.1 and that in patients with gastroduodenitis was 2.6. The drug did not produce any well-defined side effects. In some cases (8.3%), it caused the appearance or enhancement of constipation. Antepsin is indicated not only in ulcer disease but also in duodenogastric reflux, reflux gastritis and reflux esophagitis.

Chronic Disease↗
PubMed1989

[Status of the hypophyseo-adrenal system and functional morphology of the adrenal glands in residents of Northern European areas of the USSR].

Serum corticotropin and cortisol levels were measured in 20-40-year old healthy residents (144 males and 361 females) in the North. A functional Synacthen Depot test was performed in 5 volunteers. The adrenal glands from 56 males and 8 females of the same age who had died from accidents were pathohistologically and stereometrically examined. The signs of functional tension were established in the pituitary-adrenal cortex system. The Synacthen Depot test determined sufficient potentials of the organ to show responses to specific stimulation. Morphologically, a number of changes were found, which might be regarded as a prerequisite to the development of functional and pathological disturbances in the above-mentioned link of the endocrine system.

Adaptation, Physiological↗
PubMed1989

The hypothalamo-hypophysial system of the lemming, Dicrostonyx torquatus Pallas. III. Population aspects of neuroendocrine regulation.

The structure and ultrastructure of the following regions of the hypothalamo-hypophysial neurosecretory system (HHNS) in the population cycle of lemming were studied: supraoptic (SON), paraventricular (PVN) and arcuate nuclei (AN), the median eminence (ME) and posterior pituitary (PP). Being compared to the state of endocrine glands and gonads, and the level of reproduction stress in the population cycle of the lemming described earlier, the obtained data revealed a certain regularity. First, at the stages of decrease, increase and in the first period of the stage of population peak the activity of the SON-PP complex and AN is gradually increased. This coincides with intensified reproduction, intensified functioning of the thyroid gland and adrenal cortex. Second, while the population is decreasing, all the above functions become depressed, except that of the thyroid gland which, on the contrary, becomes active. In the second period of the stage of population peak, when reproduction stops abruptly, this regularity, however, does not hold, the activity of SON-PP complex and AN is sharply lowered, whereas that of PVN becomes very high. The structure of the thyroid damaged as a result of previous hyperfunction, is restored, and the adrenal cortex shows signs of hypercorticism. The present work is devoted to specificity of the HHNS functioning at the stage of population peak, referred to as crucial, and the pathways and mechanisms by which neurohormones produced by this system can affect the endocrine glands. In addition, the causes likely to lead to the mass death of animals at this stage, and biological significance of this fact are also given attention to.

Animals↗
PubMed1987

[Morphofunctional features of the development of the thyroid gland of Dicrostonyx torquatus during the drop in population stage].

By means of the histostereometrical method, peculiarities of the thyroid gland formation have been studied in the lemming (Dicrostonyx torquatus) fetuses and newborns at the stage of the population quantity drop, as well specificity of the organ's morphofunctional state during the postnatal period. On the 14th prenatal day the thyroid gland already has the follicular structure. Up to the 19th day progressive follicular growth, accumulation of colloid and increase of its density occur. On the 19th-20th days, as well as in newborn animals, there are certain signs, demonstrating as essential activation of the thyroid gland function. In the newborn animals cavities of the completely formed follicles are devastated. During the postnatal period again growth of follicles, accumulation of colloid are observed, signs of hypersecretion of the hypophysis appear.

Animals↗
PubMed1986

[Features of the development of the pituitary-thyroid system of the Wrangel Island hoofed lemming Dicrostonyx torquatus at stages of growth and peak population].

By means of morphometric techniques, peculiarities in formation of the hypophyseal-thyroid system during prenatal and early postnatal periods have been studied in lemmings (Dicrostonyx torquatus) from the Wrangel island at growth stages and at the peak of the population quantity. Folliculoformation rate, time when the organ reaches the definitive structure, periods for establishing connection with the regulating center--the anterior hypophyseal lobe, correlation of differentiation rates of histo- and ultrastructures of the organ distinctly react to changes in the density population of the animals. Periods of initiation of folliculoformation are early and comparable at both stages of the population cycles. However, further at the peak of the population quantity, an essential retardation in the development of both histo- and ultrastructures of the thyroid cells is observed; formation of the histostructure significantly overtakes differentiation of the ultrastructures composing its cellular elements. The follicular structure begins to form only in newborn animals, the folliculogenesis completes on the 1st-6th days of the postnatal period. At the stage of growth of the population quantity, the folliculogenesis lasts 2 days (the 15th-17th days of the prenatal development), the organ's structure becomes definitive on the 17th day, at the same period connections are established with the anterior hypophyseal lobe. The role of the thyroid hormones in formation of reprodactive and adaptive potencies of the organism at various stages of the population cycle is discussed.

Alaska↗