Vitamin D status of older South Africans.

OBJECTIVE: To determine the vitamin D status of older coloured' South Africans who had not sustained a fracture. DESIGN: Cross-sectional analytic study. METHODS: A random sample of 200 non-institutionalised subjects in Cape Town aged > or = 65 years was drawn using a two-stage cluster design. Trained fieldworkers interviewed subjects to obtain demographic, dietary and lifestyle data, to draw fasting blood samples for the analysis of serum 25-hydroxyvitamin D (25(OH)D) and other biochemical parameters, and to take anthropometric measurements. RESULTS: Seventeen per cent of the subjects (95% CI: 11.4-22.6%) had serum 25(OH)D levels in the deficient range for the elderly (< 10 ng/ml); 7.5% (95% CI: 3.6-11.4%) had concentrations in the moderately severe range of deficiency (< 8 ng/ml). Sixty-three per cent of the subjects had raised serum alkaline phosphatase concentrations. Regression modelling showed neither a sex difference in 25(OH)D levels nor a sex-age interaction; however, a negative association with age was found (r = -0.18; P < 0.05). Mean oral vitamin D intake was low (3.6 (SD = 2.7) micrograms and 2.8 (SD = 1.7) micrograms for men and women, respectively), but no association between dietary vitamin D intake and serum 25(OH)D was found. CONCLUSIONS: The prevalence of suboptimal vitamin D status was high. However, the interpretation of the data, with regard to bone health, is limited by the cross-sectional design of the study. Further investigation is required to determine the potential benefits of intervention in this age group.

Cloning and sequencing the degS-degU operon from an alkalophilic Bacillus brevis.

The sacU region from an alkalophilic Bacillus brevis was cloned and sequenced. The two open reading frames of the degS-degU operon encode polypeptides that gave calculated molecular masses of 43.8 kDa and 27.0 kDa, respectively. Sequence comparisons at the amino acid level to the B. subtilis degS-degU genes showed 74% and 84% similarity, respectively. On a multicopy vector the B. brevis degS-degU genes were found to cause hypersecretion of several extracellular enzymes in a B. subtilis rec- strain as well as in a B. subtilis sacU(HY) strain.

The influence of consuming fatty fish instead of red meat on plasma levels of vitamins A, C and E.

The effect of fatty fish consumption on the plasma levels of vitamins A, C and E and the intake of these vitamins were studied in 12 males and 16 females with a mean age of 32.4 years. This cross-over study had a 3 week baseline, 6 week experimental and 6 week post-experimental period with a washout period of approximately 3 months in between. Four 7 day dietary records were used to collect dietary information. Blood samples were drawn after an overnight fast at baseline and every third week thereafter. Plasma total cholesterol, high density lipoprotein cholesterol, triacylglycerol, vitamin A, C and E levels were determined. During the experimental periods red meat was consumed by half of the volunteers while fatty fish was consumed by the other half. Diets were crossed-over after the washout period. Plasma levels of vitamins A, C and E remained within normal limits in the experimental periods. The intake of polyunsaturated fatty acids (PUFA) was significantly higher in the experimental fatty fish period than in the experimental red meat period. The dietary ratio of vitamin E: PUFA and the plasma vitamin E level were lower (P < 0.01) in the experimental fatty fish period than in the experimental red meat period but the ratio of plasma vitamin E: total cholesterol plus triacylglycerol did not differ between the experimental periods. In this study none of the experimental groups were at risk in terms of their intake of the antioxidant vitamins.

Characterization, cloning and sequencing of a thermostable endo-(1,3-1,4) beta-glucanase-encoding gene from an alkalophilic Bacillus brevis.

A Bacillus brevis gene coding for an endo-(1,3-1,4)-beta-glucanase was cloned in Escherichia coli and sequenced. The open reading frame contains a sequence of 759 nucleotides encoding a polypeptide of 252 amino acid residues. The amino acid sequence of the beta-glucanase gene showed only a 50% similarity to previously published data for Bacillus endo-(1,3-1,4)-beta-glucanases. The optimum temperature and pH for enzyme activity were 65-70 degrees C and 8-10, respectively. When held at 75 degrees C for 1 h, 75% residual activity was measured. The molecular mass was estimated to be about 29 kDa on sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis and the enzyme was found to be resistant to SDS.

Blood vitamin concentrations during the acute-phase response.

OBJECTIVES: To investigate the effect, if any, of the acute-phase response on blood vitamin concentrations and to test the hypothesis that these concentrations may change during stress. DESIGN: Open study, utilizing a volunteer sample of patients. SETTING: Tertiary care center. PATIENTS: Twenty-six healthy adult volunteers (14 female and 12 male); 25 volunteers underwent uncomplicated orthopedic surgery and one suffered traumatic limb fractures. INTERVENTIONS: None. MAIN OUTCOME MEASUREMENTS: The presence of a systemic acute-phase response was documented by the determination of serum C-reactive protein concentrations. Blood vitamin concentrations were determined from sequentially collected blood samples over a 7-day period, and compared with entry values. RESULTS: The presence of the acute-phase response was documented by significant and transient increases in C-reactive protein values. This response was accompanied by significant and transient decreases in the concentrations of leukocyte vitamin C, and in plasma concentrations of vitamin A, retinol-binding protein, vitamin E, total lipids, pyridoxal-5'-phosphate, and albumin. Blood concentrations of pyridoxal-5'-phosphate, retinol-binding protein, and leukocyte vitamin C decreased to values below the respective normal ranges. These concentrations normalized without any therapeutic interventions. CONCLUSIONS: We demonstrated transient, but significant, decreases in blood vitamin concentrations during the acute-phase response. Recommendations regarding daily supplementation with these vitamins in clinical practice cannot be made on the basis of these results, as the functional importance of these observations is not, at present, clear. However, what is clear is that biochemical vitamin concentrations, determined during the acute-phase response, should be interpreted with care.

Plasma vitamin levels in patients on prolonged total parenteral nutrition.

Vitamins are essential in total parenteral nutrition (TPN), their importance being highlighted by repeated past documentation of various vitamin deficiencies particularly in patients on long-term parenteral nutrition therapy. This study evaluated the efficacy of water- (Soluvit) and fat-soluble (Vitalipid) vitamin supplementation in patients receiving total parenteral nutrition using the three in one 3-liter bag system. All patients received water-soluble vitamin supplements daily. Fat-soluble vitamin supplements were administered on a daily or twice weekly basis. Twenty-two patients were studied. In seven of the 22 patients vitamin status was assessed on more than one occasion during TPN support, thus bringing the total number of observations to 30. The mean duration of TPN support was 35 days. Eight of the observations were made during less than 10 days, three between 11-19 days, 15 between 20-60 days, and four during more than 60 days of TPN support. Biochemical deficiency as judged by subnormal enzyme activity or vitamin levels were present in 10% of the patients for thiamin, 3% for riboflavin, and 6% for nicotinic acid. By contrast 83% of the patients had low plasma vitamin C and B6 levels. Low plasma vitamin A and E levels were also present in 43 and 40% of the patients, respectively. According to the plasma concentrations of the vitamins studied it would appear that the commercial vitamin preparations used in this study are inadequate in maintaining optimal vitamin status.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of pyridoxine supplementation on plasma pyridoxal-5'-phosphate levels in children with the nephrotic syndrome.

Nineteen children with low plasma pyridoxal-5'-phosphate (PLP) levels in the nephrotic syndrome due to a variety of histological entities were successfully supplemented with oral pyridoxine hydrochloride. A dose of approximately 2 mg/kg/day of pyridoxine hydrochloride was found to effect adequate plasma PLP levels in most cases. A significant (p less than 0.001) positive correlation (r = 0.83) was found between plasma albumin and PLP levels prior to supplementation and after supplementation both in relapse and remission. Although vitamin B6 repletion led to no demonstrable effect on the clinical course of the syndrome, in view of the possible role which vitamin B6 deficiency may play in defective immune response and thromboembolic phenomena, both being known complications of the nephrotic syndrome, the administration of vitamin B6 supplements is recommended in the active disease state.

Plasma vitamin A, E, C and B6 levels in myocardial infarction.

Vitamin A, E, C and B6 status was studied in 30 patients with myocardial infarction and in 19 age- and sex-matched patients after elective surgery or trauma. Plasma levels of the four vitamins studied were low, remained low or decreased transiently in both groups of patients during the acute catabolic response phase, and began to return to normal after the third day from the start of the catabolic response. These changes in plasma levels are therefore neither of any special pathophysiological importance in nor specific to myocardial infarction.

Biochemical aspects of a study of 100 obese white subjects.

The effect of a 7 100 kilojoule diet (50% of the energy derived from carbohydrate, mainly unrefined, 30% from fat, mainly unsaturated, and 20% from protein) on 100 overweight subjects was investigated. It was found that 45% of subjects did not complete the study, 9% continued with the study but did not lose weight, 25% lost weight moderately well and 21% responded very well and lost a mean of 15,9 kg over a 6-9 month period. Very little indication of water retention was found. The following biochemical changes occurred during the study period: 1. There was a marked improvement in the glucose tolerance of the groups that lost weight effectively. 2. This improvement in glucose tolerance was associated with a very marked decrease in the secretion of immuno-reactive insulin. 3. The tendency for serum cholesterol and triglyceride levels to decrease during the study was also evidenced in the changes which occurred in the lipoprotein electrophoresis patterns. Stepwise discriminant analysis performed on biochemical, clinical and psychological data failed to provide a practical means of discriminating in advance between the likely response of subjects to this dietary therapy with acceptable accuracy.