Search PubMed⌕ Search

Biomedical subjects

R Buzina

Publications and source records attributed to R Buzina.

At least 37 records · Page 2Linked to original sources
PubMed1990

Effects of pyridoxine and riboflavin supplementation on physical fitness in young adolescents.

The effects of pyridoxine and riboflavin supplementation on physical fitness was studied in a group of children with higher prevalence of subclinical, biochemically defined pyridoxine and riboflavin deficiencies. One hundred and thirteen children aged 12-14 years were allocated to three groups to receive daily (except Sundays) for two months either a placebo or a supplement of pyridoxine or riboflavin. The supplementation resulted in marked improvement of pyridoxine and riboflavin nutrition status and was followed by disappearance of respective biochemical deficiencies. The improvement in pyridoxine biochemical status was also accompanied by a slight and statistically significant increase in physical fitness (p less than 0.05) assessed by bicycle ergometer technique. The increase in physical fitness in the riboflavin supplemented group was statistically non-significant (p greater than 0.05). In both supplemented groups there was a significant increase in physical fitness in subjects with initially deficient biochemical vitamin status whereas supplementation had no effect on physical fitness in subjects with initially high biochemical values.

Adolescent↗
PubMed1989

Effect of industrial pollution on seafood content and dietary intake of total and methylmercury.

The total mercury and methylmercury content of seafood was studied in an area of the Adriatic Sea polluted with inorganic mercury from a local industrial plant. The industrial pollution has affected both the total and the methylmercury content of seafood, but only the difference in the total mercury level was statistically significant when compared with a control area with no local industry. Studies of seafood consumption patterns indicate that, when the subjects examined from both areas were matched by their seafood consumption, both total mercury and methylmercury intake was higher in the industrially polluted area. The percentage of subjects ingesting total mercury above the WHO Provisional Weekly Tolerance Intake (PWTI) of 300 micrograms was also higher in the industrially polluted area. However, the percentage of subjects whose methylmercury intake was above the PWTI of 200 micrograms was higher in the control area, primarily due to the increased number of subjects consuming fish more than 5 times a week.

Animals↗
PubMed1989

Food consumption patterns in the 1960s in seven countries.

At the end of the 1950s the Seven Countries Study was designed to investigate the relations between diet and cardiovascular diseases. Sixteen cohorts were selected in Finland, Greece, Italy, Japan, The Netherlands, United States, and Yugoslavia. During the 1960s food consumption data were collected from random samples of these cohorts by use of the record method. In Finland the intake of milk, potatoes, edible fats, and sugar products was very high. A similar but lower intake pattern was observed in The Netherlands. Fruit, meat, and pastry consumption was high in the United States; cereal and alcoholic drink consumption was high in Italy; and bread consumption high in Yugoslavians except for those in Belgrade. In Greece the intake of olive oil and fruit was high and the Japanese cohorts were characterized by a high consumption of fish, rice, and soy products. These differences in food consumption patterns have lessened during the past 25 y.

Adult↗
PubMed1989

Nutritional status, grip strength, and immune function in institutionalized elderly.

The effects of vitamin supplementation on grip strength and immune function was studied in a group of institutionalized elderly with a relatively higher prevalence of low and below acceptable biochemical parameters of vitamin C, pyridoxine, folic acid, riboflavin, iron and zinc nutriture. The vitamin supplementation has resulted in a statistically significant increase in the level of biochemical parameters related to added vitamins, and the number of subjects with inadequate vitamin values was reduced to zero. The improved vitamin status had a positive and statistically significant effect on the delayed cutaneous hypersensitivity one of the parameters of cellular immunity. The calculation of multiple correlation after inclusion of all biochemical parameters into the stepwise regression analysis has shown that the coefficient of multiple regression between examined biochemical parameters of nutrition status and delayed cutaneous hypersensitivity was R = .599 (p less than 0.001) which indicates that about 36% of the variability in the cellular immunity would be affected by the vitamin and mineral nutrition status.

Aged↗
PubMed1986

The diet and 15-year death rate in the seven countries study.

In 15 cohorts of the Seven Countries Study, comprising 11,579 men aged 40-59 years and "healthy" at entry, 2,288 died in 15 years. Death rates differed among cohorts. Differences in mean age, blood pressure, serum cholesterol, and smoking habits "explained" 46% of variance in death rate from all causes, 80% from coronary heart disease, 35% from cancer, and 45% from stroke. Death rate differences were unrelated to cohort differences in mean relative body weight, fatness, and physical activity. The cohorts differed in average diets. Death rates were related positively to average percentage of dietary energy from saturated fatty acids, negatively to dietary energy percentage from monounsaturated fatty acids, and were unrelated to dietary energy percentage from polyunsaturated fatty acids, proteins, carbohydrates, and alcohol. All death rates were negatively related to the ratio of monounsaturated to saturated fatty acids. Inclusion of that ratio with age, blood pressure, serum cholesterol, and smoking habits as independent variables accounted for 85% of variance in rates of deaths from all causes, 96% coronary heart disease, 55% cancer, and 66% stroke. Oleic acid accounted for almost all differences in monounsaturates among cohorts. All-cause and coronary heart disease death rates were low in cohorts with olive oil as the main fat. Causal relationships are not claimed but consideration of characteristics of populations as well as of individuals within populations is urged in evaluating risks.

Adult↗
PubMed1986

Plasma levels and urinary vitamin C excretion in schizophrenic patients.

Vitamin C status was determined in schizophrenic subjects using fasting plasma levels and the urinary dose response after an oral load of 1.0 g ascorbic acid. The study was carried out in 20 schizophrenic patients and 15 controls with the diagnosis of neurosis who were on the same hospital diet for at least 2 months. The schizophrenic subjects had significantly lower fasting plasma vitamin C levels (P less than 0.05) and 6-h urinary vitamin C excretion after an ascorbic acid load test (P less than 0.01). Since urinary vitamin C excretion in both groups was significantly associated with differences in fasting vitamin C plasma levels (P less than 0.001), a new group of 15 schizophrenics and 15 controls was supplemented with 70 mg of ascorbic acid daily for 4 weeks in order to optimize and standardize their vitamin C plasma levels before the ascorbic acid loading test. The results showed that after 4 weeks of supplementation the average fasting plasma vitamin C levels were almost identical in both examined groups, but the urinary vitamin C excretion was again significantly lower in schizophrenic patients (P less than 0.05). These results are in agreement with the hypothesis that schizophrenia may be associated with impaired ascorbic acid metabolism.

Adult↗
PubMed1986

Increase of gingival hydroxyproline and proline by improvement of ascorbic acid status in man.

The 4-hydroxyproline and proline content of periodontal tissue was measured in 24 adult volunteers with initially low and partially even deficient plasma vitamin C values, before and after peroral supplementation with 70 mg ascorbic acid daily for six weeks. The latter caused a statistically significant rise and normalization respectively of plasma ascorbic acid and simultaneously a statistically significant increase of the hydroxyproline and proline in periodontal tissue (p less than 0.01) but not before the plasma vitamin C level was above 0.9 mg/dl. The optimal plasma vitamin C level which was associated with the highest hydroxyproline and proline content in periodontal tissue ranged between 1.00-1.30 mg/dl corresponding to the total daily dietary ascorbic acid intake of about 100 mg.

Adult↗
PubMed1985

Serum cholesterol and cancer mortality in the Seven Countries Study.

In the Seven Countries Study, carried out in Finland, Greece, Italy, Japan, The Netherlands, the United States, and Yugoslavia, among 11,325 "healthy" men aged 40-59 years in 15 years, there were 594 cancer deaths. Among 477 cancer deaths five years after cholesterol measurement, there was a significant excess of lung cancer deaths in the bottom 20% of the cholesterol distributions in the populations. Age, blood pressure, smoking habits, occupation, and relative body weight did not help explain this. A U-shaped relationship between cancer and cholesterol was not seen in any population. Trend analysis with various cutting points indicated increasing risk of lung cancer death at cholesterol levels under 170 mg/dl. The 45 men dead from cancer in the first two years had lower cholesterol levels than their compatriots who died from cancer later but they did not differ in relative weight or fatness. In contrast to relationships for individuals within populations, the highest cancer death rates were in northern Europe, where the general level of cholesterol was also highest. Other characteristics of the populations--age, relative weight, smoking habits, blood pressure, physical activity, and vitamin A and ascorbic acid in the diet--did not help in the attempt to understand the regional differences in cancer mortality. There is no evidence that any of the observed cancer-serum cholesterol relationships among or within the populations involve an effect of serum cholesterol concentration on oncogenesis or cancer mortality but the possibility of such an effect cannot be denied.

Adult↗
PubMed1984

The seven countries study: 2,289 deaths in 15 years.

Among 11,579 men ages 40-59 without evidence of cardiovascular disease, 2,289 died in 15 years, 618 from coronary heart disease. The 15 cohorts in seven countries (four regions) differed in all-causes death rate, mainly reflecting great differences in coronary mortality. Among characteristics of entry, only mean blood pressure helped to explain cohort differences in all-causes death rate. Three-quarters of the variance in coronary death rate was accounted for by differences in mean serum cholesterol and blood pressure of the cohorts. The mortality risk for individuals was examined in each of the regions. For coronary death, age, serum cholesterol, blood pressure, and smoking were highly significant in all regions except Japan, where coronary deaths were too few for evaluation. Relative weight was not significant anywhere. Physical activity was significant only in southern Europe, where differences are associated with socioeconomic status. For all-causes death, age and blood pressure were highly significant risk factors in all regions as was smoking habit, except in Japan. Relative body weight tended to be a negative risk factor everywhere, significantly so in southern Europe. Expectations for coronary death from the experience in the United States and northern Europe greatly exceeded observed deaths in southern Europe for men of their age, serum cholesterol, blood pressure, smoking habits, physical activity, and relative weight. The reverse, prediction of coronary deaths in America and in northern Europe from the southern European experience, greatly underestimated the deaths observed. Similar cross-predictions between the United States and northern Europe were good for all-causes deaths, excellent for coronary deaths. Analysis of time trends in relationships of mortality to entry characteristics showed continued importance of age, blood pressure, and smoking and a tendency for the importance of cholesterol to fall in the last 5 years of follow-up.

Adult↗
PubMed1984

Vitamin C status and physical working capacity in adolescents.

The effect of ascorbic acid supplementation on physical working capacity was studied in young adolescent boys in which the concomitant biochemical riboflavin and pyridoxin deficiencies were corrected by medicamentous prophylaxis. After daily administration for two months of 70 mg ascorbic acid, the mean plasma vitamin C in the experimental group (n = 49) rose from 0.33 to 1.49 mg/dl (p less than 0.001) and the prevalence of deficient plasma vitamin C values (less than 0.20 mg/dl) decreased from 52.3 percent to zero. The improvement in vitamin C biochemical status was also accompanied by a statistically significant increase in VO2 max. (p less than 0.01). There were no significant changes neither in the mean plasma vitamin C values nor in the mean VO2 max. in the control group subjects (n = 42). The increase in VO2 max. in the experimental group was primarily the result of an increase of VO2 max. in subjects with initially lower values. When data from both experimental and control groups were pooled together, a positive and significant association was found between VO2 max. and the increase of plasma vitamin C values below 1.0 mg/dl. No further increase in VO2 max. was observed when vitamin C plasma values reached 1.0 mg/dl or more. The two regression lines crossed at X = 0.86 mg/dl. This cut off point of plasma vitamin C level corresponds to a dietary intake of about 80 mg of ascorbic acid per day. The results of this study are in agreement with the suggested optimal ascorbic acid daily intake obtained by kinetic studies with (1-14C) ascorbic acid.

Adolescent↗
PubMed1982

The effect of ascorbic acid supplementation on periodontal tissue ultrastructure in subjects with progressive periodontitis.

In an attempt to determine the optimal daily ascorbic acid requirement, the effect of different levels of ascorbic acid intake on collagen synthesis was studied in a double-blind experimental design. By use of electron microscopy, interproximal gingival tissue sections in subjects consuming between 20 to 35 mg of ascorbic acid daily were examined before and after the administration of tablets containing 70 mg of ascorbic acid. The results showed that practically all subjects were affected by progressive periodontitis with marked changes in the connective tissue of the gingival lamina propria. After six weeks of supplementation with ascorbic acid, differences in the shape and activity of fibroblasts in the regenerative tissue of lamina propria were observed. This has resulted in the increased number of collagen bundles in fibroblasts' periphery, increased tonofibril content and an enlarged number of desmosomes between adjacent cells. It is concluded that the obtained results, though suggesting that the optimal daily ascorbic acid intake should be set above the presently recommended 30-50 mg, have to be quantified by a more objective analytical method.

Adult↗
PubMed1982

Nutritional status and physical working capacity.

In a population of schoolchildren aged 12-15 years in which biochemical deficiencies of vitamin C, riboflavin and pyridoxine affected 30.0, 33.9 and 17.2 per cent of subjects respectively, a small but statistically significant correlation was found between VO2max and vitamin C, riboflavin, vitamin A, and parameters of iron nutrition status. The administration of tablets containing 70.0 mg ascorbic acid, 2.0 mg riboflavin and 2.0 mg pyridoxine resulted in a statistically significant reduction in prevalence of vitamin deficiency, and in a small but statistically significant increase in VO2max. No such changes were observed in the untreated control groups. When data from both the experimental and control groups were pooled and analysed together, the results showed that the increase in VO2max was associated with an increase in plasma vitamin C level, in erythrocyte riboflavin content and in blood haemoglobin level. On the basis of presented data, it is not possible to conclude whether the increase in VO2max was the result of correction of vitamin deficiency per se or was due to its effect on resorption and utilization of dietary iron.

Adolescent↗