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Biomedical subjects

B Korać

Publications and source records attributed to B Korać.

At least 19 recordsLinked to original sources
PubMed2002

Quantification of Helicobacter pylori resistance in functional and organic dyspepsia.

OBJECTIVE: To compare the efficacy of Helicobacter pylori eradication in patients with functional and organic dyspepsia. METHODS: The study included a cohort of 160 patients (115 with organic and 45 with functional dyspepsia) with dyspeptic symptoms and gastroscopically confirmed H. pylori infection. Triple therapy with omeprazole 20 mg, amoxicillin 1000 mg and metronidazole 400 mg (OAM) was administered twice a day for a week. Minimal inhibition concentration (MIC) was estimated on cultures from 41 patients with positive H. pylori for determination of antimicrobial sensitivity and primary resistance to amoxicillin and metronidazole. RESULTS: Endoscopic examination at least 6 weeks after therapy showed that 116 (72.5%) patients had H. pylori eradicated, whereas 44 (27.5%) were not. From the latter patients, 10 (23%) had functional dyspepsia and from 116 eradicated patients 35 (30%) had functional dyspepsia. Difference in efficacy of OAM therapy between patients with organic and functional dyspepsia was not significant (P > 0.5). Percentages of non-eradicated patients with organic and functional dyspepsia were 29.6 and 22.2%, respectively (ratio 1.3 : 1). MIC from 41 samples showed 18 (44%) in vitro resistant strains. There was no resistance to amoxicillin. CONCLUSIONS: There is no significant difference in H. pylori resistance to the same antibiotic between patients having functional or organic dyspepsia.

Adolescent↗
PubMed2001

Doxorubicin toxicity to the skin: possibility of protection with antioxidants enriched yeast.

The possibility of skin protection against doxorubicin toxicity was examined after oral antioxidative pretreatment of the rats with yeast supplemented with selenium and vitamins E, C and A for 15 days. The activity and level of antioxidative defense components were monitored in the skin and blood 48 h after i.v. applied doxorubicin. In the blood, increased glutathione peroxidase activity in the erythrocytes, and amounts of vitamin E and glutathione in the plasma were found after the antioxidative treatment. It also led to an increase of the reductive capacity in the skin (increased thioredoxin reductase activity and reduced glutathione level). Doxorubicin alone, depleted reductive capacity, i.e. decreased the activity of thioredoxin reductase in the skin, as well as the content of reduced glutathione both in the skin and blood plasma. Depletion of reductive capacity represents one of the first harmful doxorubicin effects to the skin at the time when the changes of other antioxidative enzyme activities were not detectable. Reductive capacity in the skin of animals given antioxidative pretreatment was maintained elevated upon doxorubicin application in comparison with the corresponding control. Oral supplementation with antioxidants thus prevents toxic effects of doxorubicin in the skin and may contribute to the alleviation of its secondary cytotoxicity during the chemotherapy.

Administration, Oral↗
PubMed1998

Seasonal changes in the antioxidative defense in ground squirrels (Citellus citellus): possible role of GSH-Px.

As seasonal hibernators, ground squirrels decrease their body temperature to 7 degrees C and hibernate during the winter. Maintenance at 30 degrees C prevents seasonal changes of body temperature and animals remain euthermic and active. We measured selenium (Se)-dependent glutathione peroxidase (GSH-Px), as well as the activity of other antioxidative components such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) and the amount of low-molecular-weight antioxidants glutathione (GSH), ascorbic acid (AsA), and vitamin E (vit E) in spring, summer, and winter in ground squirrels continuously kept at a temperature of 30 degrees C. We examined liver and interscapular brown adipose tissue (IBAT) as thermogenic tissues, as well as the brain and the kidneys. During the winter, we found a decrease in enzymatic activity and an increase in the level of low molecular antioxidants in all tissues. Correlation analysis revealed a similarity in the composition of antioxidative defense (AD) among the tissues examined. The results obtained clearly demonstrated numerous correlative expressions of antioxidative components in this experimental model, especially of GSH-Px, suggesting the complexity of the system responsible for the maintenance of physiological homeostasis.

Adipose Tissue, Brown↗
PubMed1998

Seasonal changes in the activity of antioxidative defense in the kidneys of the euthermic ground squirrel (Citellus citellus).

The aim of this work was to determine the activity of the antioxidant enzymes: superoxide dismutase (EC 1.15.1.1; SOD), catalase (EC 1.11.1.6; CAT), glutathione peroxidase (EC 1.11.1.9; GSH-Px), glutathione-S-transferase (EC 2.5.1.18; GST), glutathione reductase (EC 1.6.4.2; GR) and the low molecular mass antioxidants: ascorbic acid (ASA) and vitamin E (vit E) in the kidney of ground squirrels during circannual changes. Keeping the ground squirrel at the temperature of thermic neutrality (30 degrees C) provides a stable euthermic state during the whole year and thus any change is due to the circannual rhythm. The highest specific activity of all examined antioxidative defense enzymes in the kidney was found in the spring, when ground squirrels are seasonally the most active. In the summer, lower specific activity of GSH-Px as well as of SOD and CAT were noted and, when expressed per g wet mass, only a decrease in GSH-Px activity was recorded. In the kidney of ground squirrels kept at 30 degrees C, the lowest specific activity of all examined enzymes was found during the winter and, when expressed per g wet mass, only the SOD activity was lower than in the spring and summer. Higher amounts of vitamins C and E were found in the ground squirrel kidneys in the summer. The results obtained in this work demonstrate that circannual regulation of metabolic activity, which is inherent to seasonal hibernators, is also expressed at the level of antioxidative defense in the kidneys.

Animals↗
PubMed1998

Effect of selenium-enriched yeast pretreatment on the antioxidative defense in the skin of rats exposed to heat shock.

Skin protection against heat shock and the specificity in the organization of antioxidative defenses were examined in rats given oral antioxidative pretreatment with selenium (Se)-enriched yeast and vitamins E, C, and A for 15 days and then exposed to hyperthermia. The activity of antioxidative enzymes in the skin and the liver was monitored 1 hour and 3 hours after heat shock. Glutathione peroxidase (GSH-Px) activity was increased in the skin after heat shock in the groups supplemented with antioxidants, but not in the controls. In contrast, the activity of liver GSH-Px was increased only in the controls receiving antioxidants. Heat shock led to a decrease in liver superoxide dismutase (SOD) activity at 1 hour in the antioxidant-supplemented group, but this was unchanged in the liver of all other groups and in the skin. The activity of thioredoxin reductase (TR) in the skin was increased in the antioxidant supplemented group 1 hour after heat shock, whereas the hepatic thioredoxin reductase activity was decreased. The activities of catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) were unaffected by either treatment. These results suggest that supplementation with antioxidants protects the skin against heat shock, especially with respect to the GSH-Px and TR activity. The different response of the skin in comparison with the liver probably reflects differences in organization and regulation of antioxidative defenses.

Animals↗
PubMed1997

Seasonal variation in the antioxidant defense system of the brain of the ground squirrel (Citellus citellus) and response to low temperature compared with rat.

Seasonal variation in the activity of antioxidant enzymes (superoxide dismutase (EC 1.15.1.1.; SOD), catalase (EC 1.11.1.6; CAT), glutathione peroxidase (EC 1.11.1.9; GSH-Px), glutathione reductase (EC 1.6.4.2; GR), glutathione-S-transferase (EC 2.5.1.18; GST) and low-molecular-weight antioxidants: ascorbic acid (AsA), vitamin E (VIT E) and glutathione (CSH+GSSG) were examined in the brain of the ground squirrels (Citellus citellus) maintained at 30 degrees C during the whole year. The highest activity (per mg protein) of antioxidant defense (AD) enzymes was found in the spring and was much lower in the summer. A further decrease in activity of CAT, GSH-Px and GST was observed in the winter. The highest levels of AsA and glutathione were recorded in winter in comparison with spring and summer. AD system in the brain of the ground squirrel and rates (maintained at thermoneutrality) exposed to low temperature (4 degrees C) for 3, 6 or 24 hr during the summer was studied as well. Summer was chosen as a period of stable euthermia for ground squirrels and in thermoregulation similar to rats. Consumption of free fatty acid and glucose during the acute exposure to low temperature was found to be species specific. In the ground squirrel, an increase in the specific activities of SOD, after 3, 6 and 24 hr, CAT after 3 and 6 hr and GR after 6 hr of exposure to low temperature was detected. When activities were expressed in U/g wet mass, an increase of SOD after 3, 6 and 24 hr (P < 0.02, P < 0.02, P < 0.005) and CAT and GSH-Px 3 hr (P < 0.01) upon exposure to low temperature was observed. In the rats, no changes in the specific activities of these enzymes after exposure to low temperature were recorded and only an increase in GST activity (U/g wet mass) after 6 hr exposure was registered. Low-molecular-weight AD components in both animal species were unchanged upon short-term exposure to low temperature. The species-specific differences in brain AD between the rats and the ground squirrels after short exposure to low temperature may be ascribed to seasonal changes of the brain activity in the latter.

Animals↗
PubMed1997

Activity of antioxidant defense enzymes and glutathione content in some tissues of the Belgrade (b/b) laboratory rat.

The activity of antioxidant defense (AD) enzymes--superoxide dismutase (SOD, EC 1.15.1.1.), catalase (CAT, EC 1.11.1.6.), glutathione peroxidase (GSH-Px, EC 1.11.1.9.), glutathione-S-transferase (GST, EC 2.5.1.18), glutathione reductase (GR, EC 1.6.4.2) and glutathione (GSH) content of the anemic Belgrade (b/b) laboratory rats--were measured and analyzed in liver, spleen, lung, heart, brain and testes in comparison with nonanemic controls. The activities of hepatic Mn SOD, CAT, GSH-Px and GST (P < 0.02, P < 0.01 and P < 0.005) were decreased in anemic, comparing with nonanemic animals, whereas the spleen CuZn SOD, Mn SOD, CAT and GSH-Px (P < 0.005, P < 0.02, P < 0.005 and P < 0.01) activities were increased. In the lung of anemic rats, Mn SOD, GSH-Px and GR (P < 0.005, P < 0.01, P < 0.05) activities were higher, whereas GST (P < 0.01) activity was lower in relation to nonanemic ones. In anemic rats, heart Mn SOD (P < 0.05) activity was increased, brain GSH-Px (P < 0.005) activity was lower, whereas GR (P < 0.02) activity was higher compared with nonanemic controls. CuZn SOD (P < 0.05) activity in the testes was elevated and GSH-Px (P < 0.05) reduced in anemic animals. GSH content was decreased in the liver (P < 0.01), lung and brain (P < 0.005) and increased in the spleen (P < 0.02) of anemic rats in relation to the controls. Our data suggest phenotype specific differences in the AD system of the Belgrade (b/b) rat tissues in comparison with nonanemic controls.

Animals↗
PubMed1993

Effect of long-term exposure to cold on the antioxidant defense system in the rat.

Catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione-S-transferase (GST) activities as well as glutathione (GSH), ascorbic acid (AsA), and vitamin E concentrations were analyzed in the blood, liver, brain, interscapular brown adipose tissue (IBAT), and small intestine of rats exposed to low environmental temperature (4 degrees C; 35, 75, and 105 d of exposure) and in controls of the same age exposed to an environmental temperature of 22 +/- 2 degrees C. Prolonged cold exposure resulted in an increase in GSH-Px in IBAT and in small intestine after 35, 75, and 105 d of exposure. Catalase activity in cold-exposed animals was higher in IBAT after 75 and 105 d of cold exposure. Glutathione reductase activity was greater in brain after 35 d, in liver after 75 d, and in IBAT after 105 d of exposure to low temperatures as compared to the controls. In contrast, GST activity was lower in liver and IBAT after 35 and 75 d of cold exposure. AsA and GSH (determined only 105 d after cold exposure) were markedly higher in IBAT, whereas plasma GSH was lower and plasma AsA was higher in cold-exposed animals. The observed changes in analysed components of the antioxidant defense system under conditions of prolonged exposure to low temperature suggest that a reorganization the activity of this system at the molecular level occurred. Although other studies indicate that a 21-d cold exposure is sufficient for adaptation of thermogenesis, the present study shows that in general, longer periods are required for the registration of the changes in the antioxidant defense system.

Adipose Tissue, Brown↗
PubMed1991

Epidemiology of Crohn's disease in Zagreb, Yugoslavia: a ten-year prospective study.

A ten-year prospective study of Crohn's disease was carried out in Zagreb, Yugoslavia. It included both inpatients and outpatients regardless of the extent and severity of the disease. The mean annual incidence rate was 0.7 per 100,000 between 1 January 1980 and 31 December 1989. There was no increase in the incidence of Crohn's disease during the study period. The prevalence of Crohn's disease was 8.3 per 100,000 on 31 December 1989. The results confirm the low frequency of Crohn's disease in central and southern Europe.

Adolescent↗
PubMed1991

Ulcerative colitis in Zagreb, Yugoslavia: incidence and prevalence 1980-1989.

We present a ten-year incidence of ulcerative colitis in Zagreb, Yugoslavia. The study included both outpatients and inpatients regardless of the extent and severity of the disease. The mean annual incidence rate was 1.5 per 100,000 inhabitants for the period of 1 January 1980 through 31 December 1989. There was no increase in the incidence of ulcerative colitis during the study period. A prevalence rate estimate of 21.4 per 100,000 inhabitants was based on July 1985 official estimated population. The results confirm the low frequency of ulcerative colitis in central Europe.

Adult↗
PubMed1991

[Serum acute phase proteins for determining disease activity of ulcerative colitis and Crohn disease].

We studied the activity assessment of ulcerative colitis and Crohn's disease by 5 acute phase reactants: C-reactive protein (CRP), alpha 1-acid glycoprotein, alpha 1 antitrypsin, haptoglobin and fibrinogen. From a large register of patients with inflammatory bowel disease (IBD) we chose randomly 91 patients: 61 with ulcerative colitis and 30 with Crohn's disease. As a reference point in the disease activity assessment we used standard clinical indices. Statistical analysis was performed by non-parametric methods: the Kruskal-Wallis and Fisher's exact test. The disease activity assessment in patients with ulcerative colitis by the index according to Powell-Tuck indicated that the patients with active disease (N = 19) had significantly higher levels of all acute phase proteins mentioned above except fibrinogen (alpha less than 0.05 to 0.001) than patients in remission (N = 42). Analysis of the same data by Fisher's exact test indicated that there had been a probability for all the proteins measured to be higher than the normal values, particullary CRP (p less than 10(-8) and the other somewhat less. In patients with Crohn's disease, the disease activity assessment was performed by 2 indices. According to "The Crohn's Disease Activity Index" (CDAI), only alpha-1 acid glycoprotein and haptoglobin (alpha less than 0.05) were higher in patients with active disease (N = 4) than in patients with remission (N = 26).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Proteins↗
PubMed1991

Prophylactic administration of ranitidine after sclerotherapy of esophageal varices.

The present trial was carried out to determine the usefulness of H2-receptor antagonist drug therapy for the prevention of esophageal bleeding and esophageal varices in patients who underwent sclerotherapy. According to randomization, out of the 58 patients, 28 received, along with the usual standard therapy, ranitidine and 30 received placebo. Ranitidine, 50 mg, was administered intravenously over a period of 3 days every 8 hours, and then 150 mg of ranitidine was given per os in the evening for one month. For improvement of hemostasis and during the elective sclerotherapies, 1% polidocanol was used as the sclerosant. During each puncture, 2 ml was injected. Injections were paravasal and intravasal. After sclerotherapy, endoscopic examinations were carried out on the third day and one month later. Necrosis was noted in 42% of the patients and esophageal mucosal inflammation in 26%. Esophageal ulcers did not occur. There was no statistically significant difference between the two groups in terms of age, sex ratio, cause of liver cirrhosis, and the Child's classification. The size of the esophageal varices had no effect on the development of esophageal mucosal changes in correlation with the quantity of sclerosant. The comparison of the two groups of patients, sclerosed for hemorrhage and sclerosed electively, showed no statistically significant difference regarding esophageal mucosal changes. No differences between the ranitidine and placebo groups of patients were observed in this indication. It can be concluded that esophageal mucosal changes probably arise as a consequence of the sclerosant, its concentration, quantity and mode of application.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMedDate not supplied

[Value of C-reactive protein in the evaluation of activity in ulcerative colitis and Crohn's disease].

We studied a value of measuring the C-reactive protein (CRP) serum concentration in the assessment of ulcerative colitis and Crohn's disease activity. From a large register of patients with the inflammatory bowel disease (IBD), we have chosen randomly 91 patients: 61 with ulcerative colitis and 30 with Crohn's disease. As a reference point in the assessment of ulcerative colitis we have used the Powell-Tuck clinical index. Nineteen patients had an active disease, and 42 were in a remission. Patients with the active disease had significantly higher levels of the CRP then the patients in remission (chi 2 = 4.99; alpha less than 0.05). Serum CRP levels and the disease activity assessment by Powell-Tuck index were in a positive correlation, according to the Fisher's exact test (p less than 10(-8)). In the group of 30 patients with Crohn's disease, the disease activity was assessed by CDAI ("The Crohn's Disease Activity Index") and by van Hees index. According to CDAI, 26 patients were in a remission, and only 4 had an active disease. According to van Hees index, there was no patient in a complete remission, 17 patients had a partial remission and 13 had an active disease. Patients with the active disease had significantly higher CRP levels then the patients in remission, according to van Hees index (chi 2 = 7.863; alpha less than 0.01), but not according to CDAI (not significant). Meanwhile, the Fisher's exact test suggested a high positive correlation between the disease activity assessment with both indexes, either CDAI or van Hees, and the CRP serum values (alpha less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

C-Reactive Protein↗
PubMedDate not supplied

[Cigarette smoking and ulcerative colitis--is there a causal relationship?].

The relation between cigarette smoking and ulcerative colitis was assessed in a case-control study of 235 cases of ulcerative colitis and 311 age- and sex-matched control subjects admitted to the hospital for conditions unrelated to smoking. Smoking habits and daily number of cigarettes smoked were analysed. We found significantly less number of smokers and more ex-smokers in the ulcerative colitis group. The intensity of smoking was equal in both groups. It was noted that pancolitis occurred more frequently in the ex-smokers group. The intensity of smoking did not influence the extension and clinical course of ulcerative colitis. For ulcerative colitis, the relative risk for nonsmokers was 7.4. The study revealed a positive correlation between nonsmoking and ulcerative colitis, higher incidence of pancolitis among ex-smokers and higher relative risk of ulcerative colitis for never-smokers. Various possible causes of influence of smoking on ulcerative colitis are discussed.

Adolescent↗