Search PubMed⌕ Search

Biomedical subjects

R Zivković

Publications and source records attributed to R Zivković.

At least 19 recordsLinked to original sources
PubMed2000

Coffee and health in the elderly.

Coffee is a very attractive but not a unique drink. There are various types of coffee, e.g. Arabica, Canephora, and Robusta. In addition, various coffee blends containing several coffee types of different origin are offered in coffee-houses in Croatia and worldwide. These coffee blends can differ substantially according to their components, especially to the proportion of caffeine. Caffeine is the major coffee constituent which the coffee tolerance or intolerance depends on. In a healthy liver, the majority of caffeine is degraded by the hepatic microsomal enzymatic system. Caffeine is mostly degraded to paraxanthine substances, partially to theobromine and theophylline, and a small amount of unchanged caffeine is excreted by urine. Therefore, the metabolism of caffeine depends on the state of this enzymatic system of the liver. Elderly individuals with a depleted enzymatic system do not tolerate coffee with caffeine. They are recommended to take decaffeinated coffee, and this only if their stomach is healthy, because both decaffeinated coffee and coffee with caffeine cause heartburn. Moderate amounts of coffee (50-100 mg of caffeine or 5-10 g of coffee powder a day) are well tolerated by a majority of elderly people, who enjoy to meet and chat over a cup of coffee. Excessive amounts of coffee, however, can in many individuals cause very unpleasant, exceptionally even life-threatening side effects. Therefore, elderly persons are recommended to take moderate amounts of coffee which will not cause any health impairments.

Aged↗
PubMed2000

Nutrition and dietetics--neglected subjects in medical education.

A brief historical review of the development of nutrition and dietetics in the world is followed by concise description of the history of the discipline in Croatia after the foundation of the School of Medicine in Zagreb in 1919. As differentiated from the Schools of Medicine in Zagreb, Rijeka, Osijek and Split, the third, nutritional curriculum at the School of Food Science and Biotechnology has allocated as many as 280 theoretical and 110 practical periods in the form of seminars (15 periods) and practical exercise (95 periods) to nutrition and dietetics. The curriculum includes special course of lectures in dietetics, delivered by a physician specialized in the field. This is followed by the observation that none of the four Croatian Schools of Medicine in Zagreb, Rijeka, Osijek and Split has introduced systematic education in the field in either undergraduate or postgraduate curricula. There are only some sporadic related topics included in undergraduate and postgraduate studies. Thus, the paper points to the serious neglect of this important subject in the curricula of our medical schools, and present some ideas how to solve the problem in the nearest future. The possible organization of a special postgraduate study in nutrition and dietetics for physicians willing to devote themselves professionally to this field of medicine is strongly advocated, because modern nutritional practices and dietetics are likely to soon impose the need of such experts in every large hospital and clinical department.

Croatia↗
PubMed1999

Probiotics or microbes against microbes.

The brief historical survey of the discovery of Lactic Acid Bacteria (LAB) is followed by an account of the studies of LAB, since 1965 by many researchers named probiotics or biotherapeutic agents. However, as their action also involves certain antibiotic characteristics, the term "biotherapeutic bacteria" appears to suit them best. The favorable clinical effect of many LAB on various pathologic states in humans, especially in children, has now been positively demonstrated. Clinical success achieved by particular LAB in different pathologic conditions is described, with special reference to the scientifically verified effects of LGG, which has also been used in Croatia for the manufacture of fermented dairy products since 1998.

Animals↗
PubMed1998

Dietary fiber and retrograde starch.

The history of the recognition of the importance of dietary fiber, their current classification into water-soluble and water-insoluble fiber, and lignin, a single non-carbohydrate fiber, and the physiologic role of dietary fiber, with particular reference to retrograde starch resistance to small intestine digestion, are briefly presented. Dietary fiber are highly hygroscopic, thus they greatly contribute to stool voluminosity by binding water, decrease the glycemic index, and exert a protective action, via an as yet unknown mechanism, against the occurrence of colon cancer. It should be added that some dietary fiber decrease the concentration of cholesterol in the blood, i.e. in the human body. The importance of the methodology used for NSP determination is underlined, since some methods determine only some of the polysaccharides, other also measure some other substances, whereas Englyst's method determines NSP only.

Cholesterol↗
PubMed1998

Ultrasound diagnosis of acute viral hepatitis.

In acute viral hepatitis, ultrasound examination of the liver also reveals pathologic changes of other organs, especially of the gallbladder and, less frequently, of the pancreas and regional lymph hilar nodes. Ninety patients divided into 3 groups of 30 patients each, suffering from viral hepatitis (group 1), acute calculous cholecystitis (group 2) or liver cirrhosis (group 3), were prospectively analyzed. An increased gallbladder wall thickness of 4.67 +/- 0.66 mm was recorded in all group 1 patients. In the group with acute viral hepatitis, gallbladder wall thickening was only present during the first week of the disease, and was almost two-fold thinner than that found in the group with acute calculous cholecystitis, where it ranged from 4.3 to 10.3 mm. The gallbladder wall thickening in cirrhosis patients was found to depend on liver decompensation during the course of cirrhosis.

Acute Disease↗
PubMed1997

Historical development of Croatian radiology.

The history of the development of Croatian radiology is described, from the first beginnings to the present. Very soon after Roentgen's discovery in 1895, not only communications and informative lectures, but also the first x-ray device appeared in Zagreb and then in many other towns in Croatia. The first specialists in roentgenology and x-ray technician were educated at Professor Holzknecht's Roentgenology Institute in Vienna. After the opening of the University School of Medicine in Zagreb in 1917/1918, the Chair of Roentgenology, headed by Professor L. Popović, was founded as early as 1922. Here the first specialization for physicians was organized. After the second world war, with the foundation of Medical Schools in Rijeka, Osijek and Split, Croatian radiology steadily progressed. Autonomous departments and institutes for diagnostic and therapeutic radiology were organized at all large medical centers. Thanks to gynecologists, ultrasound has not only developed at radiologic units, but also at departments of gastroenterology, orthopedics, pediatrics and others. Today, there are many units for interventional ultrasonography throughout Croatia. Radioisotope units have also been organized, but only in the main medical centers, rarely in small ones. At present, there are five radiotherapy and oncology institutions in Zagreb, and one in Rijeka, Split and Osijek. Interventional radiology has been well organized since the 80s, and the First Congress of Diagnostic and interventional Radiology was held in Rijeka in 1994. In conclusion, there is no doubt that the Croatian radiology keeps pace with the international advances in the field.

Croatia↗
PubMed1989

[Evaluation of disorders of portal and total hepatic blood flow in patients with chronic diffuse liver diseases].

The total hepatic blood flow measured with radioactive colloidal gold and the portal blood flow with the echo-Doppler method were investigated in 19 healthy examinees and 63 patients with chronic diffuse liver diseases. In the group of healthy examinees, the average values of the total hepatic blood flow was 1254 +/- 231 ml/min and of the portal one 1104 +/- 227 ml/min. The lowest blood flow values were obtained in patients with decompensated cirrhosis, especially in the hepatic (704 +/- 186 ml/min) and the portal blood flow (562 +/- 198 ml/min). In all the groups of examinees, registered values of the total hepatic blood flow were significantly higher than the values of the portal blood flow. The relations of the values obtained by both methods, among groups, were similar. By both methods decreased values are not obtained in liver steatosis and chronic persistent hepatitis in relation to the normal values. In patients with more serious forms of chronic diffuse liver diseases (cirrhosis and chronic active hepatitis) significantly lower blood flow values than the normal ones were obtained. Both methods contribute to the investigation of liver circulation disturbances, liver function damages, and to the follow-up of the liver disease course. The possibility of an indirect evaluation of the arterial hepatic blood flow from the difference of hepatic and portal blood flows may mean a new approach to the investigation of pathophysiological liver occurrences.

Adult↗
PubMed1987

Activation and desensitization of glycolysis by stimulation of adenylate cyclase in rat reticulocytes.

Isoproterenol or forskolin induce a 10-15-fold increase in concentration of cyclic AMP in rat reticulocytes as compared with the basal level of 2.3 +/- 0.3 microM. Glycolysis is stimulated by both compounds transiently more than 2-fold with a peak after 7.5 min followed by an exponential decline. The glycolytic rate in the presence of 10 microM isoproterenol or 10 microM forskolin did not return to basal levels within 60 min of incubation, but was depressed by as much as 50% under the influence of 100 microM forskolin. This phenomenon is designated as metabolic desensitization. The stimulation of glycolysis is probably due to activation of phosphofructokinase as well as to stimulation of Na+,K+-ATPase. The diminished glycolytic flux during the period of metabolic desensitization is accompanied by a decline of glucose 6-phosphate and in the presence of high concentrations of forskolin also by a decrease in glucose 1,6-bisphosphate. A lower rate of influx of glucose is postulated.

1-Methyl-3-isobutylxanthine↗
PubMed1981

Effects of dibutyryl-cANP on glycolysis in washed human erythrocytes.

The experiments were carried out with washed human erythrocytes in order to study the effects of dibutyryl-cAMP (DB-cAMP) on glycolysis. 5 mM DB-cAMP significantly increases glucose consumption and lactate production in incubated erythrocytes. The cross-over plot of glycolytic intermediates shows that increased glycolysis is probably the result of activation of phosphofructokinase by DB-cAMP. Under the same condition DB-cAMP significantly protects the 2,3-diphosphoglycerate level in incubated erythrocytes.

2,3-Diphosphoglycerate↗
PubMed1981

[The role of cAMP in the energy metabolism of human erythrocytes].

In human red blood cell there is complete adenyl cyclase--cAMP system. However, the role of this system and its connection with energy metabolism in red cell is not known. Hence, we studied the effects of cAMP and DB-cAMP on energy metabolism in human red cell. Blood was taken out from haematologically healthy volunteers. Red cells were isolated by differential centrifugation and washed three times in Tris-Ringer buffer (pH 7.4). The red cells suspensions (in the above buffer) were simultaneously incubated without additions (control) and with cAMP or DB-cAMP (5 mmol/L). Incubation temperature was 37 degrees C. The samples of suspensions for the extraction of metabolites and cofactors were taken at 0 and 180 minutes of incubation. The lactate, glucose, G6P, F6P, TP, ATP, ADP and AMP were determined in neutralized perchloric acid extracts by specific enzymatic methods. Results of our experiments show that cAMP and DB-cAMP significantly increase red cell glycolysis. Under the same conditions these nucleotides induce positive "cros-over" point at the phosphofructokinase (PFK) step of the glycolysis. The levels of adenine nucleotides (ATP, ADP, AMP) were unchanged through a whole period of incubation. We concluded that cAMP and DB-cAMP stimulates glycolytic process in red cells probably by allosteric activation of PFK.

Adenine Nucleotides↗
PubMed1981

[The effect of thrombin on glycolysis in human thrombocytes].

The experiments were carried out in order to study the mechanism of thrombin--induced stimulation of glycolysis in washed human platelets. The platelets, isolated from human blood and resuspended in Krebs-Ringer-phosphate buffer (pH 7.4), were incubated in water bath (37 degrees C) either without (control) or with thrombin (1 NIH U/ml platelet suspension). Lactate, glycolytic intermediates and adenine nucleotides were measured in the neutralized perchloric acid extracts of platelets by enzymatic analysis and using the fluorimetric methods. The results of this study show that thrombin significantly increases the rate of lactate production in washed human platelets. At the same time thrombin induces the profound changes in the levels of platelet glycolytic intermediates with the "crossover" point at phosphofructokinase step of glycolysis. The results are interpreted as indicating that thrombin stimulates platelet glycolysis through allosteric phosphofructokinase activation due to the changes in adenine nucleotides energy charge.

Adenine Nucleotides↗