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Biomedical subjects

A A Iakovlev

Publications and source records attributed to A A Iakovlev.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Structure of the pentaene antibiotic roseofungin].

Roseofungin is a pentaene antibiotic of the subgroup of carbonyl conjugated pentaenes. Oxidation of the antibiotic perhydroderivative in succession with potassium permanganate and chromic anhydride resulted in formation of 2-methyltridecan dicarboxylic acid evident of the methyl branching in the roseofungin chromophore. To justify the position of the oxygen-containing functions, the polyoles resulting from reduction of the antibiotic and the products of its isonolysis were investigated by mass-spectrometry. The use of lithium alumina boron deiteride and sodium boron deiteride as reducers provided determination of two carbonyls (C11 and C17) in the roseofungin molecule. 13C NMR spectroscopy revealed the presence of the hemiketal ring formed at the expense of carbonyl C17 and carbonyl C21.

Antifungal Agents↗
PubMed1985

[Clinical characteristics of the course of acute viral hepatitis B in middle-aged and aged patients].

The clinical manifestations of acute virus hepatitis B were studied and compared in 109 elderly and senile patients (group I) and in 103 young patients (group II). In all the patients, the clinical diagnosis was confirmed by HBsAg demonstration in the peripheral blood. It was established that hepatitis B ran a severe and medium-severe course in 93.5% of the group I patients. In severe hepatitis B, intoxication was marked in 44.6% of the group I and in 65.3% of the group II patients. In group I, it was more prolonged reaching on an average 21 +/- 2 days versus 13 +/- 3 days in group II. The liver increased by 4 cm and more in 27.52% of the group I patients and in 9.71% of the group II patients. In the group I patients, the liver size returned to normal by the discharge from hospital less frequently than in the group II patients whatever the disease severity. Splenomegaly was noted in 6.42% of the group I patients only with a severe hepatitis B, and in 23.3% of the group II patients. In the group I patients with a severe hepatitis B, bilirubinemia reached a maximum at the eleventh day of jaundice or later (71.4%). In 64.3% of the group II patients, the maximum was seen within the first ten days of jaundice. In the group I patients, more severe disease patterns correlated with more marked hyperfermentemia ALAT (31.7 +/- 1.59 mmol/h.l. in a severe pattern, 26.9 +/- 1.29 mmol/h.l. in a medium-severe pattern). In the group II patients, no relationship was found between the degree of hyperfermentemia and disease severity.

Acute Disease↗
PubMed1984

[Relation between the renin-angiotensin and kallikrein-kinin systems of the blood during physical loading of hypertension patients].

Blood angiotensin-converting enzyme, renin, kallikrein and prekallikrein ratios were investigated in 61 essentially hypertensive patients at rest and during rationed exercise. Biochemical findings were compared with major parameters of systemic hemodynamics measured under the same conditions. Grouping of patients on the basis of renin activity was mirrored in different levels of the angiotensin-converting enzyme and kallikrein: increased renin activity was accompanied by the activation of the said enzymes, and reduced activity, by their suppression. Rationed exercise did not produce noticeable kallikrein-kinin shifts in hypertensive patients, their renin-angiotensin response depending on the baseline. The markedness of hemodynamic change in response to exercise differed in patients with different humoral background.

Adult↗
PubMed1984

[Radioimmunoassay in the diagnosis of arterial hypertension].

The paper is concerned with the results of a study of the aldosterone concentration and renin activity, the general level of catecholamines and their fractions (epinephrine, norepinephrine and dopamine) in the peripheral blood and blood taken at selective venography from the vena cava inferior, renal and adrenal veins of 108 patients with hypertension, aldosteroma and idiopathic hyperaldosteronism, adrenal and extraadrenal pheochromocytoma, renovascular and renoparenchymatous arterial hypertension. The aldosterone concentration and renin activity were determined with radioimmunoassay, and the general content of catecholamines and their fractions with a radioenzymatic method using standard kits. It has been shown that the radioimmunoassay to determine the aldosterone concentration and renin activity in the blood from the vena cava inferior, renal and adrenal veins makes it possible to resort to differential diagnosis of hypertension, aldosteroma, idiopathic and secondary hyperaldosteronism. A considerable increase in the blood plasma renin activity on the affected side was revealed in the patients with renovascular hypertension, and in renoparenchymatous hypertension it was equal in both renal veins. The study of the total content of catecholamines and their fractions in the blood from different parts of the venous system can be used for topical diagnosis of adrenal and extraadrenal pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1983

[Effect of beta-endorphin on endocrine function].

It has been disclosed that beta-endorphin exerts marked effect on the secretion of ACTH, prolactin, corticosterone, aldosterone and somatotrophin formation in the pituitary but does not produce any effect on blood thyrotropin. Maximal rise in the concentration of the hormones was seen at the 20th minute, despite the fact that an elevation in the content of some hormones was recorded at the 5th minute following intravenous injection of beta-endorphin. At the 60th minute after beta-endorphin injection the content of prolactin, corticosterone and aldosterone in the blood dropped to the control level, while ACTH content remained significantly higher than in intact animals. One of the possible mechanisms underlying the action of beta-endorphin on the secretion of the hormones indicated might be the changes in the ratio of brain monoamines (a decrease in dopamine).

Adrenocorticotropic Hormone↗
PubMed1982

[Renin, kallikrein and angiotensin converting enzyme in human physical loading].

The authors studied the correlation between the activity of renin, angiotensin-converting enzyme, the activity of prekallikrein and the blood prekallikrein level in men performing veloergometric exercise. At the same time they recorded the hemodynamic parameters (systolic and diastolic arterial pressure, the systolic rate, stroke volume and cardiac index, specific peripheral resistance). The blood samples collected before and immediately after the exercise showed a 41.4%-increase in the activity of renin and a 95%-increase in that of kallikrein, whereas the level of prekallikrein and the activity of the converting enzyme declined by 19 and 13% (P less than 0.05). These changes were accompanied by an increase in the systolic rate (by 107%) and in the systolic arterial pressure (by 36.7%), as well as by a reduction of the specific peripheral resistance (by 41.4%).

Adult↗
PubMed1981

[Effect of peritol on the activity of the hypothalamo-hypophyseo-adrenal system].

A study was made of the activity of the hypothalamo-hypophyseo-adrenal system under the effect of peritol (ciprohepatadin), an antagonist of serotonin receptors. Experiments were carried ot on male rats in which the blood content of corticosterone, aldosterone and ACTH was determined 3, 6 hours and 14, 20 and 30 days after peritol administration (twice a day). Pronounced inhibitory effect on the hypothalamo-hypophyseo-adrenal system was found to be attainable on a more frequent exposure (every 3 hours) to peritol with a purpose of maintaining the optimal drug concentration in various body tissues. The latter circumstance gives rise to peritol effect which is realized through both the central mechanisms (ACTH content) and as a result of direct action on steroid output.

Adrenocorticotropic Hormone↗