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Biomedical subjects

V A Iakovlev

Publications and source records attributed to V A Iakovlev.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

[State of the endocrine and cardiovascular systems in patients with somatotropin-producing hypophyseal adenoma].

Altogether 16 persons with STH-producing hypophyseal adenoma were investigated by tacho-oscillography, total rheography, blood taken from the ulnar vein, a radioimmunoassay to determine the levels of STH, ACTH, cortisol, deoxycorticosterone, aldosterone, T3, T4, vasopressin, prostaglandin E2, 6-keto-prostaglandin F1 alpha, and plasma renin activity. Acromegalic patients demonstrated an elevated level of STH, and prostaglandin E2 secretion was inhibited. Two groups of patients were singled out according to the hemodynamic state: the 1st group was characterized by a hyperkinetic type of circulation and normotension of borderline hypertension; the 2nd group was characterized by hypokinetic circulation, increased vascular resistance, labile or stable arterial hypertension. The interrelationship of hemodynamic and hormonal indices was unnoticed. It has been assumed that of pathogenetic importance in the development of arterial hypertension is depletion of E2 production, and at early stages--body liquid retention resulting from hypersomatotropinemia.

Adenoma↗
PubMedDate not supplied

[Organization and methodology of the process of examinations in internal diseases in higher education].

The authors developed a system for examinations at the stage of postgraduate advanced training for therapists which included fundamental and practical classes. Fundamental classes are presented with certain tests with regard to the curriculum while the practical ones are based on the evaluation of professional clinical skill demonstrated at the examination of the patient. The developed system is realized with the help of computerized programmes CM-4. High objectivity and the wide spectrum of the programme evidence the practicability of the methods developed in the evaluation of knowledge in therapists.

Curriculum↗
PubMedDate not supplied

[Use of potentiometric titration at constant pH for determination of the activity of lipoprotein lipase].

A method is developed for determination of the lipoprotein lipase activity. The method is based on the steady state potentiometric titration at constant pH value of higher fatty acids, liberated during the hydrolysis. An oil emulsion intralipid, activated by human blood serum, was used as a substrate. The sensitivity of the method was equal to 0.004-0.010 micronM of fatty acids per min. The reproducibility of the results was 2-5%. This simple and rapid method enabled to study kinetic of reactions, catalyzed by lipoprotein lipases.

Animals↗
PubMedDate not supplied

[Kinetic studies of the formation of abortive ternary complex lactate dehydrogenase (isoenzyme h4)-NAD-pyruvate].

The rate constants and equilibrium constants for four stages of process of the abortive ternary complex lactate dehydrogenase (porcine isoenzyme H4)-NAD-pyruvate formation are determined. These stages are 1) the enolization of pyruvate, 2) the formation of binary complex enzyme-NAD, 3) the formation of "intermediate" ternary complex enzyme-NAD-enol and 4) the transformation of "intermediate" complex into "final" ternary one, accumulation of the latter being followed by spectrophotometric and fluorometric methods. The constants obtained were compared with the corresponding ones for porcine isoenzyme M4 determined in earlier work. It was shown that the greater stability of ternary complex and the greater initial rate of ternary complex formation in the case of H4 is due to greater affinity of isoenzyme H4 with respect to NAD, greater magnitude of reaction rate constant for transformation of "intermediate" ternary complex into "final" one and lesser magnitude of reaction rate constant for the reverse transition.

Animals↗
PubMedDate not supplied

[The relationship between the level of hypophyseal adrenocorticotropic activity and the character of the tissue distribution of exogenously labeled ACTH].

Experiments were conducted on rats--intact, adrenalectomized and dexamethasone-treated; a study was made of the dynamics of incorporation into the kidneys, liver, adrenal glands, the thyroid gland and elmination from the blood plasma of iodated corticotropine of the hypophysis (Hum-ACTHid-28, Richter). It was revealed that the character of incorporation and elimination of the exogenous labeled ACTH depended on the state of the adrenocorticotropic activity of the hypophysis of the recipient rats. The period of semielimination of the iodated corticotropin of the hypophysis from the blood plasma of intact rats constituted 11.2 minutes. The hormone was not included into the parenchyma of the adrenal cortex. The rate of excretion through the kidney and catabolism in the liver of labeled ACTH increased with elevation of the level of endogenous ACTH in the blood. The period of semiexcretion of ACTH-I131 from the blood plasma of adrenalectomized animals constuted 6.4 min. With decrease of the level of endogenous ACTH in the blood due to the block of the hypophyseal secretion with decamethasone elimination of exogenous labeled hormone from the circulation was markedly retarded T1/2 = 17 min). Under these conditions ACTH-I131 was incorporated into the tissue of the adrenal cortex for 9 min. A conclusions was drawn that the period of semielimination of the exogenous iodated ACTH could be used as a criterion for the assessment of the adrenocorticotropic activity of the hypophysis of the animals-recipients.

Adrenal Cortex↗
PubMedDate not supplied

[Properties of urease immobilized by chemical binding to a derivatives of cellulose].

A comparative study of properties of soluble urease and urease immobilized by its binding to cellulose derivatives was carried out. Upon chemical binding of urease to cellulose derivatives the Mikhaelis constant and pH optimum for the enzyme action changed insignificantly. Maximum enzymic activity of soluble and immobilized urease occurred at 50 degrees C. The energy of activation of urea hydrolysis by urease during enzyme immobilization also changed insignificantly.

Catalysis↗
PubMedDate not supplied

[Effect of physical exercise conducted at various times of the day on the regulation of carbohydrate metabolism in patients with diabetes mellitus].

A study was made of the levels of glucose, IRI, STH, ACTH and cortisol in the blood serum (plasma) of 39 patients with diabetes mellitus prior to and after physical exercise testing. 25 patients performed physical exercises on an empty stomach in the morning (8-9 a.m.) 14 patients in the daytime (4-5 p.m.). Exercise therapy in the morning hours resulted in the readjustment of hormonal regulation characterized by the predominance of the activity of the counterinsular systems over the insular one. In the daytime the IRI level in patients with diabetes mellitus increased and the activity of the hypophyseoadrenal system before and after physical exercise testing decreased as compared to morning indices producing a beneficial effect on the carbohydrate metabolic status. Daytime hours seem optimum for exercise therapy of patients with diabetes mellitus of both types.

Adolescent↗