PubMed Health⌕ Search

Biomedical subjects

N A Kuznetsov

Publications and source records attributed to N A Kuznetsov.

At least 19 recordsLinked to original sources
PubMed2001

Electrolyte changes in plasma and urine of athletes during acute and rigorous bed rest and ambulatory conditions.

Rigorous bed rest (RBR) induces significant electrolyte changes, but little it is not known about the effect of acute bed rest (ABR) (i.e., abrupt confinement to a RBR). The aim of this study was to measure urinary and plasma electrolyte changes during ABR and RBR conditions. The studies were done during 3 d of a pre-bed-rest (BR) period and during 7 d of an ABR and RBR period. Thirty male trained athletes aged, 24.4 +/- 6.6 yr were chosen as subjects. They were divided equally into three groups: unrestricted ambulatory control subjects (UACS), acute-bed-rested subjects (ABRS), and rigorous-bed-rested subjects (RBRS). The UACS group experienced no changes in professional training and daily activities. The ABRS were submitted abruptly to a RBR regimen and without having any prior knowledge of the exact date and time when they would be subjected to an RBR regimen. The RBRS were subjected to an RBR regime on a predetermined date and time known to them from the beginning of the study. Sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and phosphate (P) in plasma and urine, plasma renin activity (PRA) and plasma aldosterone (PA), physical characteristics, peak oxygen uptake, and food and water intakes were measured. Urinary Na, K, Ca, Mg, and P excretion and plasma Na, K, Mg, Ca, and P concentration, PRA, and PA concentration increased significantly (p < or = 0.01), whereas body weight, peak oxygen uptake, and food and water intakes decreased significantly in the ABRS and RBRS groups when compared with the UACS group. However, urinary and plasma Na, K, Mg, P, and Ca, PRA, and PA values increased much faster and were much greater in the ABRS group than in the RBRS group. Plasma and urinary Na, K, Ca, Mg, and P, PRA and PA levels, food and water intakes, body weight, and peak oxygen uptake did not change significantly in the UACS group when compared with its baseline control values. It was shown that RBR and ABR conditions induce significant increases in urinary and plasma electrolytes; however, urinary and plasma electrolyte changes appeared much faster and were much greater in the ABRS group than the RBRS group. It was concluded that the more abruptly motor activity is ended, the faster and the greater the urinary and plasma electrolyte change.

Adult↗
PubMed2000

Measurements in calcium-supplemented athletes during and after hypokinetic and ambulatory conditions.

STUDY OBJECTIVE: Hypokinesia (diminished movement) induces significant calcium (Ca) changes, however, little is known about Ca deficiency during hypokinesia (HK). By using Ca supplements during and after HK, the aim of this study was to establish whether HK could contribute to Ca deficiency. DESIGN AND METHODS: Studies were done during the pre-HK period of 30 days, HK period of 364 days and post-HK period of 30 days. Forty male trained athletes aged, 25.0 +/- 7.7 yr were chosen as subjects. They were equally divided into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented ambulatory control subjects (SACS), and supplemented hypokinetic subjects (SHKS). The SHKS and SACS groups took daily 55.0 mg elemental Ca per kg body weight. Hypokinetic subjects were limited to an average walking distance of 0.7 km/day, while the control subjects were running 11.6 km/day. RESULTS: Fecal Ca, urinary Ca, and urinary phosphate (P) excretion, serum ionized calcium (Ca(I)), P and total Ca levels, intact parathyroid hormone (iPTH), 1,25 dihydroxyvitamin D (1,25(OH)(2)D(3)), fluid and food intakes, peak oxygen uptake, and physical characteristics were measured. During HK fecal Ca, urinary Ca, and urinary P excretion and serum P, Ca(I), and Ca level increased significantly (p < or = 0.01), whereas during the initial days of post-HK decreased significantly (p < or = 0.01) in the SHKS and unsupplemented hypokinetic subjects groups when compared with the SACS and UACS groups, respectively. During HK serum 1,25(OH)(2)D(3), iPTH levels, food and fluid intakes, body weight, body fat, and peak oxygen uptake decreased significantly (p < or = 0.01), while during the initial days of post-HK remained significantly (p < or = 0.01) depressed and fluid intakes increased significantly (p < or = 0.01) in the SHKS and unsupplemented hypokinetic subjects groups when compared with SACS and UACS groups, respectively. Serum, urinary and fecal Ca changed much more in the SHKS than UHKS. Serum, fecal, and urinary minerals, iPTH, 1,25(OH)(2)D(3) levels, food and fluid intakes, body weight, body fat, and peak oxygen uptake did not change markedly in the SACS and UACS groups when compared with their baseline values. CONCLUSION: It was shown that serum Ca concentration, urinary, and fecal Ca excretion increased during HK and decreased significantly during post-HK. Oral Ca supplementation did not significantly affect serum Ca levels or urinary and fecal Ca loss. It was concluded that decreased urinary and fecal Ca loss during post-HK, may suggest the presence of Ca deficiency during prolonged HK.

Adolescent↗
PubMed2000

Calcium supplementation effect on calcium balance in endurance-trained athletes during prolonged hypokinesia and ambulatory conditions.

Calcium (Ca) supplements may be used to normalize Ca-balance changes but little is known about the effect of Ca supplements on Ca balance during hypokinesia (decreased kilometers per day). The aim of this study was to evaluate the effect of daily intakes of Ca supplements on Ca balance during hypokinesia (HK). Studies were done during 30 d of a pre-HK period and during 364 d of a HK period. Forty male athletes aged 23-26 yr were chosen as subjects. They were divided equally into four groups: unsupplemented ambulatory control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented hypokinetic subjects (SHKS), and supplemented ambulatory control subjects (SACS). The SHKS and UHKS groups were kept under an average running distance of 0.7 km/d. In the SHKS and SACS groups supplemented with 35.0 mg Ca lactate/kg body weight. Fecal Ca loss, urinary excretion of Ca and phosphate (P), serum concentrations of ionized calcium (CaI) total Ca, P, and Ca balance, intact parathyroid hormone (iPTH) and 1,25 dihydroxyvitamin D (1,25(OH)2D), anthropometric characteristics and peak oxygen uptake were measured. Fecal Ca excretion, urinary Ca and P excretion, serum CaI, total Ca, and P concentration, and negative Ca balanced increased significantly (p < or = 0.01) in the SHKS and UHKS groups when compared with the SACS and UACS groups. Serum, urinary, and fecal Ca changes were much greater and appeared much faster in the SHKS group than in the UHKS group. Serum iPTH and 1,25 (OH)2 D, body weight, and peak oxygen uptake decreased significantly (p < or = 0.01) in the SHKS and UHKS groups when compared with the SACS and UACS groups. In contrast, the corresponding parameters remained stable in the SACS and UACS groups when compared with the baseline control values. It was concluded that during prolonged HK, urinary and fecal Ca excretion and serum Ca concentration increased significantly despite the presence of a negative Ca balance; thus, Ca supplements cannot be used to normalize negative Ca balance during prolonged HK.

Adult↗
PubMed2000

[Laparoscopic and standard cholecystectomy: comparison of immediate results].

The advantages of laparoscopic cholecystectomy (LChE) are undoubtable in comparison with traditional one. However the experience showed, that LChE is not devoid of some shortcomings. It is characterized by the same typical complications as in ChE, besides it may be followed by some specific complications. The literature concerning the rate of complications in LChE are controversial. The comparative analysis has been carried out concerning the rate of complications after ChE (6800 operations) and LchE (900). The mean age of patients with choledocholythiasis--61.4 years. 40% of the patients had severe accompanying diseases coronary artery disease, complicated forms of arrythmia, arterial hypertension, diabetes mellitus, obesity. There were no significant differences between patients who underwent ChE (group 1) and LChE (group 2) by their age and the rate of accompanying diseases. Intraoperative cholangiography was performed in 3.5% of cases of group 1 and in 1.1%--in group 2. The average rate of the operations on extrahepatic bile ducts in group 1 was also lower--choledocholithotomy was carried out in 2.7%, transduodenal papillosphyncterotomy--in 1.7% of cases, drainage of the choledochal duct--in 1.9%. Combined operations were carried out in 10% of patients of group 1 and in 9.1% cases of group 2. The rate of intraoperative bleedings which demanded repeated operations made up in patients of group 1 0.1%, in patients of group 2 0.5%. Intraoperative damage of the choledochal duct in group 1 were detected in 0.14% and in group 2--in 0.11% of cases (the only complication of LChE in a patient was assessed as a endogenous wall clipping).

Cholecystectomy↗
PubMed1999

Potassium loading effect on potassium balance in athletes during prolonged restriction of muscular activity.

Negative potassium balance during hypokinesia (decreased number of kilometers taken/day) is not based on the potassium shortage in the diet, but on the impossibility of the body to retain potassium. To assess this hypothesis, we study the effect of potassium loading on athletes during prolonged hypokinesia (HK). Studies were done during 30 d of a pre-HK period and during 364 d of an HK period. Forty male athletes aged 23-26 yr were chosen as subjects. They were divided equally into four groups: unloaded ambulatory control subjects (UACS), unloaded hypokinetic subjects (UHKS), loaded hypokinetic subjects (LHKS), and loaded ambulatory control subjects (LACS). For the simulation of the hypokinetic effect, the LHKS and UHKS groups were kept under an average running distance of 1.7 km/d. In the LACS and LHKS groups, potassium loading tests were done by administering 95.35 mg KCl per kg body weight. During the pre-HK and HK periods and after KCl loading tests, fecal and urinary potassium excretion, sodium and chloride excretion, plasma potassium, sodium and chloride concentration, and potassium balance were measured. Plasma renin activity (PRA) and plasma aldosterone concentration was also measured. Negative potassium balance increased significantly (p < or = 0.01) in the UHKS and LHKS groups when compared with the UACS and LACS groups. Plasma electrolyte concentration, urinary electrolyte excretion, fecal potassium excretion, PRA, and PA concentration increased significantly (p < or = 0.01) in the LHKS and UHKS groups when compared with LACS and UACS groups. Urinary and fecal potassium excretion increased much more and much faster in the LHKS group than in the UHKS group. By contrast, the corresponding parameters change insignificantly in the UACS and LACS groups when compared with the base line control values. It was concluded that urinary and fecal potassium excretion increased significantly despite the presence of negative potassium balance; thus, negative potassium balance may not be based on potassium shortage in the diet because of the impossibility of the body to retain potassium during HK.

Adult↗
PubMed1999

[Combined operations for cholelithiasis].

The experience of 1560 combined operations performed in N.N.Burdenko clinic from 1974 to March 1999 for cholelithiasis is analysed. The results of 7461 cholecystectomies are analysed depending on patients' age (17.8% of patients aged 65 years and older), urgency of the operations (there were 35.6% of patients of this age group who underwent surgery under strictly urgent conditions), and complicacy of the operation (combined operations were carried out in 837 patients with cholecystitis). Last years in the clinic each 10th cholecystectomy is carried out as an additional procedure in more complicated surgery, or it is combined with less complicated one. Thus, in 389 patients with more complicated diseases than cholelithiasis (approximately in a half of them tumors of various locations were observed), cholecystectomy was performed as a combined procedure (1st group), and in 448 patients (2nd group) it was the main procedure. In the 1st group 27% of patients were aged 65 years and older, the overwhelming majority of the operations were carried out by the same approach, mortality rate being 3.3%. In the 2nd group elderly patients made up 20.7%; 68.3% of patients were operated by two approaches, lethality rate being 0.2%. Thus, lethality after 837 combined operations made up 1.7%, total mortality rate after 7461 cholecystectomies made up 0.29%.

Aged↗
PubMed1999

Calcium metabolism in bone and teeth of rats during exposure to restriction of motor activity and to swimming exercise.

The effects of motor activity restriction for 90 days (hypokinesia, HK) and swimming training (T) on calcium metabolism in rat bones and teeth were evaluated. Male Wistar rats were distributed in four groups: untrained vivarium control rats (UVCR), untrained hypokinetic rats (UHKR), trained hypokinetic rats (THKR) and trained vivarium control rats (TVCR). Hypokinesia was obtained keeping the animals for 90 days in small individual cages which restricted their movements in all directions without hindering food and water intakes. Rats of THKR and TVCR were forced to swim for 15 to 90 minutes everyday. On the 1st, 7th, 15th day of a prehypokinetic period and on the 5th, 10th, 20th, 40th, 60th and 90th day of the hypokinetic period, six rats of each group were decapitated. Radioactive calcium was injected to the animals 70 days before autopsy. Calcium and phosphorus in serum, bones (molars, incisors, upper and lower jaws, parietal, scapular, clavicle, pelvic and tibial bones) and in the respective ash residues were measured. Body and bone weights, and radioactive calcium were also determined. Under prolonged exposure to HK (THKR and UHKR groups), bone weights and bone and ash Ca and P concentrations decreased, whereas serum Ca and P and 45Ca resorption increased, in comparison to the respective values in the UVCR and TVCR groups. Swimming exercise apparently did not modify calcium metabolism in the hypokinetic or control rats.

Animals↗
PubMed1997

Water metabolic parameter changes in rhesus monkeys during exposure to prolonged restriction of motor activity.

The objective of this investigation was to determine the effect of prolonged restriction of motor activity (hypokinesia [HK]) on several parameters of water metabolism in primates. The studies were performed on 12 rhesus monkeys aged 4-5 yr (5.10-6.85 kg) during the hypokinetic period of 90 d and during the prehypokinetic period of 30 d. They were divided into two equal groups: the first group was placed under ordinary vivarium conditions (vivarium control animals) and the second group was subjected to 90 d of HK (hypokinetic animals). For the simulation of the hypokinetic effect, the primates were immobilized on their abdomens in special tables. The legs of the monkeys were immobilized with hip and knee joints extended. The primates retained freedom of movement at elbow, wrist, and ankle. During the pre-experimental period of 30 d and during the experimental period of 90 d, the following variables were determined: body weight, total body fluid content, specific total body fluid, mean fluid consumed and eliminated in urine, specific plasma resistance, hematocrit level, and plasma concentrations of sodium (Na) and potassium (K). In the hypokinetic primates, body weight decreased significantly when compared to the controls. Mean fluid intake, total body fluid, and specific total body fluid decreased, whereas mean daily fluid loss and specific mean daily fluid elimination increased significantly. Specific plasma resistance, hematocrit level, and plasma electrolyte concentrations increased significantly when compared to the control primates. It was concluded that prolonged restriction of motor activity induces significant changes in water metabolic parameters of primates leading in decreased total water content of the body.

Animals↗
PubMed1995

[Problems in the surgical treatment of calculous cholecystitis].

The article analyses experience of the N. N. Burdenko clinic in surgical treatment of cholelithiasis. A total of 4,733 operations for cholecystectomy were performed. 96.7% of them were of a planned order, 14.3% of patients who underwent operation 65 years of age and older. Cholecystectomy was expanded to choledocholithotomy in 2.7, papillosphincterotomy in 1.7, separation of biliodigestive fistules in 0.6% of cases. Various combined operations were carried out on 558 patients. Intraoperative complications developed in 0.96% of cases: damage to the hepaticocholedochus (0.14%) and to the hepatic artery proper (0.02%) and its right branch (0.02%). Relaparotomy was performed in 0.86% of cases: for bile leakage (0.54%) and for bleeding (0.15%). Suppuration occurred in 3.9% of patients who were operated on. Total mortality was 0.25% (0.09% after planned and 5.7% after emergency operations). Fatal complications were encountered in 0.1% of patients under 65 years of age and in 1.18% of older patients. Fatal outcomes occurred in 1.1% of 558 combined operations, one of which was cholecystectomy; in none of the cases could the fatal complication be connected with expansion of the intervention. As it can be seen from the above-discussed material, there are definite prospects for improving the results of cholecystectomy: an obligatory condition is conduction of the operation in a planned order and under 65 years of age. Careful assessment of the operative risk factors for each patients on the basis of modern mathematical methods will help in solving the problem of the possibility of surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗