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Biomedical subjects

L A Ivanov

Publications and source records attributed to L A Ivanov.

At least 19 recordsLinked to original sources
PubMed2003

[Effect of hypoxia on respiration system in aging].

The purpose of the research was to investigate the peculiarities of ventilatory reaction to hypoxia with the elderly and old people. 27 practically healthy young (20-35 years), 24 elderly (60-74 years) and old (older 74 years) people were examined. The influence of hypoxia on the gas exchange was investigated during the respiration of gas mixtures with 17% and 12.5% of oxygen content (during 12 minutes), that corresponds to 1500 m and 4000 m above sea level. The parameters of ventilating function of the lung were determined on the spirograf CT-1M. Oxygen tension in arterial blood (PaO2) was determined with the device "AVL" by "OMNI" (Austria). The curves of ventilating dependence on PaO2 for the young and old people are plotted using the mathematical model. It was shown, that with aging the "steepness" of curve's dependence on the ventilatory answer from the degree of hypoxemia decreases, that testifies to the decrease of chemoreflex sensitivity.

Adult↗
PubMed1995

[The echographic assessment of the activity of the inflammatory process in patients with chronic acalculous cholecystitis in the choleretic test].

Ultrasonic investigations of the gallbladder in choleretic test were carried out in 186 patients with chronic acalculous cholecystitis (CAC): 47 with intensive, 76 with moderate and 31 with minimal exacerbation, 32 patients in remission and 36 control subjects. As shown by choleretic test, a reduction of latent period and gallbladder contraction duration, a decrease in discharged bile amount, bile discharge velocity, initial and final gallbladder volumes' ration and increased final gallbladder volume occurred in CAC patients. These changes were parallel to inflammation intensity. Three types of gallbladder contraction were revealed in choleretic test: a 3-phase contraction curve with the initial fast evacuation period, relaxation wave (enlarged gallbladder) and slow evacuation period (type 1); a 2-phase curve with fast and slow evacuation (type 2); a monophasic curve with slow evacuation (type 3). In the patients studied type 1 prevailed, while type 3 was not observed in the controls. With increasing inflammation activity in CAC patients a type-1 contraction frequency declined and disappeared in active exacerbation, whereas type 2 and especially type 3 contractions became more frequent.

Adolescent↗
PubMed1995

[Pulmonary ventilation function in middle-aged and elderly patients with chronic bronchitis].

The indices of lung ventilation and biomechanics of breathing were determined in 48 patients with chronic obstructive bronchitis (COB) aged 60-79 and 45 healthy subjects of the same age. Inpatients with COB a rise of lung ventilation, work of breathing, ventilation equivalent, positive reaction to oxygen, a decrease of maximal breathing capacity and reserve of breathing take place that reflect excessive and uneffective ventilation, limitation of its functional performance. These specific features are due to an increase in the total lung capacity at the expense of residual volume against a decrease of vital capacity with diminution of alveolar ventilation to lung ventilation ratio. But of decisive significance was disturbance of bronchial patency manifesting in a decrease of Tiffeneau index, midexpiratory flow, respiratory flows in forced respiration, especially in expiratory phase, concavity of flow-volume curve to volume axis, a rise of bronchial resistance.

Aged↗
PubMed1994

[Bronchial resistance and its determining factors in middle and old age].

In 65 apparently healthy elderly and old subjects (aged 60-89) and 26 young ones (aged 18-35) the bronchial resistance (Raw) was determined by means of simultaneous recording of esophageal pressure and a pneumotachogram. In the aged an increase of Raw, especially during expiration, and a decrease in specific conductance of lungs were found. In the group of young subjects the Raw was increased in women. In the aged the sex differences in Raw were levelled.

Adolescent↗
PubMed1994

[Method of constrictive anastomosis].

A combined cuff suture was elaborated in the clinic for the formation of a functioning constrictor and prevention of suture incompetence in various anastomoses. The method of its application is discussed and the results of its testing in gastroduodeno- and gastrojejunostomy in animal experiments are shown. The cuff suture was used in the clinic in 129 patients, in operative management of obstruction of the hepaticocholedochus and biliodigestive anastomoses in 77, in formation of constrictor digestive anastomoses after resection of the stomach and gastrectomy in 42 patients, and in cystogastrostomy in one patient with favorable functional outcomes. The functional condition of the stomach which was operated on and biliopancreatic system was studied by modern informative methods. The technique was also used in treatment of a duodenal stump after operations on the stomach in 27 patients and in closure of defects and injuries of hollow organs of the digestive tract and in ileotransversostomy under conditions of peritonitis in 9 patients. Fatal outcomes in 5 patients who underwent operation and postoperative complications in 13 cases were not connected with the operative method.

Adult↗
PubMed1991

[Changes in gastric secretory function in peptic ulcer patients after gastric resection].

Gastric function was studied in 69 peptic ulcer patients in the long-term period after gastric resection according to Billroth-I and Billroth-II. Enzyme-producing function of the stomach was appraised according to the blood pepsinogen content, acid-forming function was assessed with the aid of intragastric pH-metry, and mucus-forming one in accordance with the content of hexosamines and sialic acids in gastric juice. The patients showed different alterations in gastric function. A correlation analysis was used to establish the role played by the neurohormonal systems (leu-enkephalin, beta-endorphin, gastrin, somatotropin, triiodothyronine, thyroxine, cortisol) in the derangement of secretory function of the resected stomach. The data obtained enable one to come closer to understanding the ineffectiveness in some cases of drug and surgical therapy of peptic ulcer. On the other hand, specification of the regularities of the impairment of secretory function of the stomach will be helpful in elaborating methods of gastric function correction at the neurohormonal level.

Adult↗
PubMed1990

[Current view on the pathogenetic factors of hypoxia in middle-aged and aged persons].

Pulmonary ventilation, gas exchange, respiration biomechanics, respiratory function of the blood, and the tissue level of PO2 in functional tests have been studied in a group of healthy individuals aged 20-106 years. Aging has been found to be associated with oxygen deficiency including the circulatory and tissue hypoxia elements. The relationship between hypoxia and aging has been confirmed, and the mechanisms by which specific oxygen-deficiency components develop have been outlined. The adaptive hypoxia-related changes in elderly and senile ages have been specified. Based on the current concepts of the pathogenic factors underlying hypoxia in aging, the methodologies are proposed to reverse the hypoxia-related changes in these age groups.

Adult↗
PubMed1986

[Mechanisms of the effect of propranolol on the oxygen transport function of the blood in elderly patients with ischemic heart disease].

In vivo effects of varying concentrations of propranolol on the oxyhemoglobin dissociation curve, and its in vitro effects on erythrocyte energy metabolism were studied in 12 elderly and old coronary patients. An 80 mg oral dose of propranolol evoked a significant shift to the right in the oxyhemoglobin dissociation curve due to a decrease in blood pH (Bohr's effect) and, according to in vitro evidence, the release of membrane-bound ATP and 2,3-diphosphoglycerate. As a result, propranolol improved blood oxygen release in tissue capillaries, as evidenced by elevated pO2 in subcutaneous fat.

2,3-Diphosphoglycerate↗
PubMed1984

[Effect of hyperoxia on the oxyhemoglobin dissociation curve in various periods of aging].

Gas composition of the arterial and venous blood and the oxyhemoglobin dissociation curve were determined before and after 20 minutes of oxygen inhalation in 9 apparently healthy subjects aged 60 to 74 years and in 9 young subjects aged 19 to 32 years. In hyperoxia of younger subjects, there was a shift to the left of both the oxyhemoglobin dissociation curve of the native blood and standard dissociation curve (pH 7.4). In old age, the shift to the left of the standard dissociation curve due to hypoxia was quite negligible and statistically insignificant, whereas in the native blood it was entirely absent because of the increased blood PCO2 and associated Bohr effect.

Adult↗