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Biomedical subjects

P Rust

Publications and source records attributed to P Rust.

At least 19 recordsLinked to original sources
PubMed2006

B-vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans.

BACKGROUND: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. OBJECTIVE: The nutritional status of various B-vitamins (B(1), B(2), B(6), B(12), folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. METHODS: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B(1), B(2) and B(6) in urine and the concentrations of vitamin B(6) and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B(12) and folic acid were measured with radioimmunoassay. RESULTS: Most of the subjects showed a satisfying vitamin B(1) status. Vegans presented a significantly lower mean plasma vitamin B(12) concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B(6) deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45-50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. CONCLUSION: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B(12) and B(2) may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.

Adult↗
PubMed2004

Serum carotenoid and retinol levels during childhood infections.

BACKGROUND: In recent years, new physiological functions of vitamin A have been identified, including its role in immune defense. The antioxidant potential of carotenoids is thought to account for their health benefits. The aim of this study was to investigate the concentration changes in the provitamin-A (alpha- and-beta-carotene, beta-cryptoxanthin) and of the non-provitamin-A carotenoids (lutein, zeaxanthin and lycopene) in children with acute infections. METHODS: Serum retinol and carotenoid concentrations were measured by HPLC in 45 children suffering from acute infections and in 29 healthy controls. In addition 15 healthy children collected food samples over 2 days. C-reactive protein (CRP) levels were measured by turbidimetry. RESULTS: Serum levels of beta-carotene, alpha-carotene, beta-cryptoxanthin and retinol and non-provitamin-A carotenoid lutein and zeaxanthin concentrations were significantly lower in children with infections compared to healthy controls. There were significant negative correlations between CRP levels and serum beta-carotene and retinol concentrations. The average intake of retinol equivalents was 1.1 +/- 0.6 mg/day. CONCLUSION: Serum retinol and provitamin-A as well as non-provitamin-A carotenoid concentrations were lower in children with acute phase infections compared to healthy controls. The inverse correlations between CRP and beta-carotene or retinol indicate either decreased synthesis or increased utilization of these antioxidants.

Adolescent↗
PubMed2003

Standard errors in mixture studies of tuberculous infection prevalence.

Tuberculous infection status in individuals assessed by skin injections of 5 TU PPD-S tuberculin are subject to error. Some truly infected persons may respond with a small skin induration, and some not infected with Mycobacterium tuberculosis can respond with a large induration. Rust and Thomas used data from 701,317 white US Navy recruits seen during 1961-1968 to describe induration size distributions among those infected and not infected, and to provide prevalence estimates. Here, standard errors of prevalence and induration size probabilities are presented through use of the jack-knife methodology.

Epidemiologic Methods↗
PubMed2001

Relationship between dietary intake, antioxidant status and smoking habits in female Austrian smokers.

BACKGROUND: Previous studies have shown that cigarette smoke contains many oxidants and free radicals, which can increase lipid peroxidation. AIM OF THE STUDY: The association between smoking, food pattern, especially vitamin intake and plasma concentrations of important antioxidants, as well as lipid peroxidation products was assessed in this cross-sectional study. SUBJECTS AND METHODS: Sixty Austrian women aged 18-40 y were enrolled in the study. Twenty-nine women were allocated to the smoking group; thirty-one women served as nonsmoking controls. Plasma concentrations of alpha- and gamma-tocopherol, alpha- and beta-carotene, lycopene, cryptoxanthin, retinol, ascorbate and malondialdehyde were determined by HPLC; dietary intake and food pattern had been assessed by four 24-h dietary intake recalls and one food frequency questionnaire. RESULTS: Generally, food intake patterns were not different between smoking and nonsmoking women. But, a significantly higher intake of alcohol was observed in the smoking group (P < 0.05). Plasma ascorbic acid concentration of the smoking group did not differ from the nonsmoking women. Despite the increased utilization because of the oxidative stress in smokers, this result might be explained by the high dietary intake of vitamin C in our smoking group. Significantly lower plasma concentrations of alpha-,beta-carotene and lycopene have been partly ascribed to the enhanced metabolic turnover resulting from smoking-induced oxidative stress. Our results confirm that smoking had no effects on plasma tocopherol and plasma retinol concentrations. CONCLUSIONS: The poor supply with the carotenoids alpha-, beta-carotene and lycopene may result from the increased metabolism of antioxidants caused by oxidative stress and may be responsible for significantly higher levels of lipid peroxidation products in smokers compared to nonsmokers (P < 0.05).

Adolescent↗
PubMed2001

The thiamine status of adult humans depends on carbohydrate intake.

Thiamine requirements for humans are generally expressed as absolute values per day (mg/d) or in relation to total caloric intake. Limited data are available on the relation between thiamine requirements and the intake of carbohydrates. This study was performed to investigate the influence of stepwise increases of carbohydrate intake on the status of thiamine in healthy volunteers under isocaloric conditions. During an adaptation phase of four days, the carbohydrate intake of twelve healthy volunteers (6 male, 6 female) was 55% of total energy intake. During the subsequent intervention periods, carbohydrate intake was increased to 65% of total energy for four days and to 75% for another four days. Thiamine intake, total energy intake, and physical activity were kept constant throughout the study. HPLC analysis was used to measure thiamine in plasma, urine and feces. Erythrocyte transketolase activity (ETK) was determined enzymatically. During the intervention periods thiamine decreased significantly (p < 0.05) in plasma (from 19.3 +/- 3.3 to 16.4 +/- 4.0 nmol/l) as well as in urine (from 72 +/- 56 to 58 +/- 21 mumol/mol creatinine). ETK and feces content of thiamine remained unchanged. An increase of dietary carbohydrate intake from 55% to 65% and 75%, respectively, of total caloric intake for four days per period at isocaloric conditions causes a decrease of plasma and urine levels of thiamine without affecting enzyme activities.

Adult↗
PubMed2001

Gliomatosis cerebri: pitfalls in diagnosis.

We report two young patients with obscure presentations of gliomatosis cerebri. Initial CT scanning was inconclusive and in one case showed intraventricular haemorrhage, a feature not previously described. Magnetic resonance imaging was required to show the lesions with greater definition; however, in both cases, a biopsy was needed to confirm the diagnosis.

Adult↗
PubMed2001

Effects of beta-carotene supplementation for six months on clinical and laboratory parameters in patients with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) have significantly decreased plasma concentrations of nutrient antioxidant vitamins, especially of beta-carotene, which is thought to result from fat malabsorption and chronic pulmonary inflammation. The aim of this double blind, placebo controlled study was to investigate the effect of oral beta-carotene supplementation for six months on clinical parameters. METHODS: Twenty four patients with CF were randomised to receive beta-carotene 1 mg/kg/day (maximum 50 mg/day) for three months (high dose supplementation) and 10 mg/day for a further three months (low dose supplementation) or placebo. At monthly follow up visits the plasma beta-carotene concentration, total antioxidant capacity, malondialdehyde (MDA) as a marker of lipid peroxidation, and clinical parameters (Shwachmann-Kulczycki score, body mass index (BMI), height, and lung function (FEV(1))) were assessed. The number of pulmonary exacerbations requiring antibiotic treatment (in days) three months before and during the study were evaluated. RESULTS: The plasma concentration of beta-carotene increased significantly to the normal range during the three months of high dose supplementation (baseline 0.08 (0.04) micromol/l to 0.56 (0.38) micromol/l; p<0.001) but decreased to 0.32 (0.19) micromol/l in the period of low dose supplementation. Initially raised plasma levels of MDA fell to normal levels and the total antioxidant capacity showed a non-significant trend towards improvement during high dose supplementation. Antibiotic treatment decreased significantly in the supplementation group from 14.5 (14.9) days/patient during the three months before the study to 9.8 (10.3) days/patient during high dose supplementation (p=0.0368) and to 10.5 (9.9) days/patient during low dose supplementation, but increased in the placebo group. The Shwachmann-Kulczycki score, lung function, and BMI did not show any changes in either of the treatment groups. No adverse events were observed during the study period. CONCLUSION: Oral beta-carotene supplementation in a dose of 1 mg/kg/day only was effective in normalising the plasma concentration of beta-carotene and resulted in a decrease in pulmonary exacerbations. These data suggest that patients with CF may benefit clinically from supplementation with beta-carotene and further studies are warranted.

Adolescent↗
PubMed2000

Long-term oral beta-carotene supplementation in patients with cystic fibrosis - effects on antioxidative status and pulmonary function.

To investigate the efficacy of long-term oral beta-carotene supplementation for optimizing the antioxidant status and pulmonary function in patients with cystic fibrosis (CF), 24 patients (aged 12. 8 +/- 6.3 years) were randomized to a CF supplementation or to a CF placebo group. As controls 14 healthy age-matched subjects (aged 14. 7 +/- 6.2 years) were studied. Patients of the CF supplementation group received 1 mg beta-carotene/kg body weight (BW)/day (maximally 50 mg beta-carotene/day) for the first 12 weeks; during the following 12 weeks, dosage was reduced to 10 mg beta-carotene/day. At study entry, plasma beta-carotene concentrations were significantly lower in CF patients than in controls (p < 0.001). In the CF supplementation group, plasma beta-carotene concentrations were significantly increased (baseline: 0.08 +/- 0.04 micromol/l) at the end of high-dose treatment (12th week; 0.6 +/- 0.4 micromol/l; p < 0.001), but decreased again during supplementation with 10 mg beta-carotene/day to 0.3 +/- 0.2 micromol/l at the end of the study (p < 0.001). beta-Carotene supplementation did not affect plasma concentrations of other carotenoids and retinol, but an increase in plasma alpha- and gamma-tocopherol concentrations was noticed. During high-dose treatment, a significant decrease in TBA-MDA complexes and a correction of total antioxidative capacity was observed. During the treatment, pulmonary exacerbation could be corrected significantly (p < 0.05). We conclude that CF patients can be efficiently supplemented with 1 mg beta-carotene/kg BW/day (maximally 50 mg beta-carotene/day) to achieve plasma concentrations of healthy control subjects and to minimize oxidative stress, improving the quality of life of CF patients.

Adolescent↗
PubMed2000

Vascular compression of the rostral ventrolateral medulla in sympathetic mediated essential hypertension.

The pathophysiological factors of neurogenic or sympathetically mediated essential hypertension are unknown. Neurons close to the surface of the ventrolateral medulla (specifically, in the retro-olivary sulcus [ROS]) are integrally involved in the control of blood pressure by means of efferent connections to presympathetic neurons in the spinal cord. It is hypothesized that vascular contact with the ROS is pathogenically involved in neurogenically mediated hypertension. We evaluated that theory in 20 subjects with uncomplicated stage 1 to stage 2 essential hypertension (EHTN) (18 of whom completed the study). The baseline supine plasma norepinephrine level served as an index of central sympathetic outflow. The response of blood pressure to clonidine was used as a surrogate marker for neurogenically mediated hypertension. We also examined the relationship between those markers and evidence of anatomic abnormalities in the area of the ROS that was provided by magnetic resonance imaging. A vessel contacted the left ROS in 5 of the 18 subjects. Those 5 subjects had higher plasma norepinephrine concentrations than did the 13 subjects without this vascular contact (358+/-46 versus 76+/-43 pg/mL, P<0.001). These 5 subjects also exhibited a significant depressor response to clonidine that tended to be greater than that seen in the 13 subjects without vascular contact (-20.6+/-3.2 versus -13.6+/-9 mm Hg). Both race and baseline mean blood pressure had only an independent effect on the depressor response to clonidine. The findings are consistent with the theory that vascular contact with the left ROS may contribute to neurogenically mediated "essential" hypertension in some patients.

Adult↗
PubMed1999

Individualized outcome feedback produces voluntary antiemetic prescribing practice changes.

STUDY OBJECTIVE: To determine the impact of individualized outcome feedback on antiemetic prescribing practices and compare outcomes of a cost-effective, standardized antiemetic protocol (PROT) to that of customized antiemetic therapy (NONPROT). DESIGN: Prospective, observational study with randomized component. SETTING: Postanesthesia care unit (PACU) of an academic medical center. PATIENTS: 3027 consecutive ASA physical status I, II, and III patients receiving general anesthesia. INTERVENTIONS: Patients were randomized to receive 0.625 mg droperidol or 4 mg ondansetron for postoperative nausea and/or vomiting (PONV) from a protocol, or received customized antiemetic therapy. MEASUREMENTS AND MAIN RESULTS: Incidence of PACU PONV, selection of PROT versus NONPROT, patient satisfaction, and use of PONV prophylaxis were measured and indexed by an attending anesthesiologist in a monthly report for 4 months. Monthly expenditures for antiemetic therapy prior to, during, and after the study were collected. Literature on PONV outcomes, appropriate timing, and selection of PONV prophylaxis was distributed. The NONPROT group was slightly older than the PROT group; otherwise, demographics were similar between all groups. The incidence of PONV did not differ between the PROT and NONPROT groups (11% vs. 10%), and the incidence of PONV in patients receiving prophylaxis was higher in both groups (17% PROT vs. 15% NONPROT). Patients receiving ondansetron as a first-line drug required rescue therapy less often (5%) than those receiving droperidol (14%); however, patient satisfaction was indistinguishable among all groups. During the study, the use of prophylaxis decreased 47% without an increase in PONV, and PROT selection increased 54%. CONCLUSIONS: Individualized outcome feedback produced a 48% reduction in monthly expenditures for ondansetron and droperidol, which was sustained after the study. Patients satisfaction between ondansetron 4 mg and droperidol 0.625 mg given in the PACU did not differ in spite of a slightly greater efficacy of ondansetron as a first-line drug.

Adult↗
PubMed1999

[Investigations on the sulfate concentration in milk substitutes and milk products and its effect on feces composition in calves].

In continuing investigations on effects of milk replacers with high ash and mineral contents (KAMPHUES et al., 1999a) on feces' quality and composition in calves in the present study the sulfate concentration (and its effects) in milk replacers and whey products were proved. In 13 samples of milk replacers the SO4 concentration varied between 2.4 and 6.7 g/kg dry matter, in 14 samples of dried whey products SO4- concentrations of 1.4 up to 41.8 g/kg dm were found. In general higher sulphur contents were caused by higher concentrations of sulfate. In feeding a milk replacer (6.7 g SO4/kg dm) about 20% of the consumed sulfate were excreted via feces (app. digestibility of about 80%). In experiments with elevated SO4 intake (in liquid diets: 560-1980 mg/l) the digestibility rate of sulfate decreased dose dependently (75-->65%). By analysis of milk replacers (used in previous experiments, TSCHENTSCHER, 1998) resulting in diarrhea in all treated calves unexpected SO4- concentrations were found of 16.3 and 10.2 g/kg dm. In feeding experiments (6 calves) by addition of Na2SO4 (85%) and MgSO4 (15%) sulfate concentration in the liquid diet was elevated from 560 mg to 1980 mg/l. Here the SO4 concentration in the diet and the dry matter content in calves' feces were correlated significantly (r = -0.86). Presented results on the SO4 concentration in milk replacers and the observed effects of sulfate intake on feces quality (i.e. dry matter content of feces) indicate by the first time that the SO4 content in milk replacers and dried whey products is an essential parameter when an estimation of milk replacers or whey products' quality is required.

Animal Feed↗
PubMed1998

Effects of long-term oral beta-carotene supplementation on lipid peroxidation in patients with cystic fibrosis.

The aim of this study was to determine the efficacy of oral beta-carotene supplementation for the correction of an oxidant-antioxidant imbalance in cystic fibrosis (CF). We studied 24-patients with cystic fibrosis and 14 healthy controls. 13 CF-patients were allocated to a CF-supplementation group, which received 1 mg beta-carotene/kg BW/d up to a body weight (BW) of 50 kg, patients with a BW greater 50 kg received 50 mg beta-carotene/d for 12 weeks. For the following 12 weeks all patients of the CF-supplementation group were treated with 10 mg beta-carotene/d. Placebos with starch were applied to 11 CF-patients. Baseline plasma beta-carotene concentrations of CF patients (mean +/- SD, 0.08 +/- 0.04 mumol/l) were significantly lower than those of age-matched controls (o.3 +/- 0.1 mumol/l) (p < 0.001). beta-carotene concentrations of the CF-supplementation group increased rapidly and reached a value of 0.6 mumol/l after 12 weeks of supplementation. Normal values were measured for plasma ascorbate and alpha-tocopherol. Plasma retinol concentrations were in the lower normal range and did not increase during supplementation. Total antioxidative capacity in plasma of the CF-supplementation group increased after 12 weeks of supplementation at an extent of 12%. Positive influence was indicated by a decrease of plasma malondialdehyde. Thus oral beta-carotene supplementation is effective in normalizing status of beta-carotene and malondialdehyde in CF patients.

Adolescent↗
PubMed1998

Identifying persons with dementia by use of a caregiver telephone interview.

A telephone screening assessment designed to identify persons likely to have dementia was conducted in a random community sample of 4,403 adults. Because of the cognitive impairment of the subjects, information was obtained from caregivers. Twenty-nine subjects were identified as likely to have dementia. Of these, 15 agreed to a complete dementia assessment conducted in their residence, and all were diagnosed with dementia. There was high reliability between the caregiver telephone interview and the clinical examination.

Aged↗
PubMed1997

Glucometer analysis of one-hour glucose challenge samples.

OBJECTIVE: Our purpose was to explore a cost-saving measure for diabetes screening by using glucometer testing on venous whole blood obtained after a 1-hour glucose challenge test. Glucometer results falling above an upper threshold would predict abnormal plasma values and mandate a glucose tolerance test; results below the lower threshold would predict normal plasma values and avoid further testing. Results between the thresholds would require traditional plasma analysis. STUDY DESIGN: We performed a prospective cohort study on 222 consecutive pregnant women. A standard 50 gm glucose screen was performed with venous blood drawn at 1 hour. We immediately removed a drop of whole blood from the venous sample and analyzed it on a portable glucometer, Accu-Chek III. The remaining sample was submitted immediately for routine plasma analysis. All values were obtained on the same glucometer, which was calibrated daily in our clinic laboratory. Regression analysis was performed on 129 samples to select the two thresholds. The selected thresholds were then applied prospectively to the next 93 consecutive samples for validation. RESULTS: Excellent correlation (r = 0.9045) exists between the glucometer and laboratory values. Glucometer threshold values of 110 mg/dl and 155 mg/dl were selected because they predicted plasma values < 135 mg/dl or > 135 mg/dl with 95% certainty, respectively. Prospectively, the thresholds were completely accurate in classifying the values. CONCLUSION: Venous whole blood assayed by glucometer can reliably predict an elevated or normal automated plasma glucose value. By applying thresholds, three fourths of all patients can immediately receive reassuring information, whereas the patients with poorest glucose tolerance are immediately identified and diagnostic testing is scheduled. Additionally, our model reduces the number of automated laboratory studies by 80% and reduces the cost of diabetic screening.

Blood Glucose↗
PubMed1989

Urinary tract cancers found by homescreening with hematuria dipsticks in healthy men over 50 years of age.

In a homescreening study 235 asymptomatic men, 50 years of age and older without known causes of hematuria, tested their urine each week with a chemical reagent strip for the presence of blood for 1 year. Forty-four men had hematuria at least once, and 31 had a full urologic evaluation. Of these, eight were found to have urinary cancers and seven had nonmalignant diseases warranting immediate treatment. In six of these 15 men (only two with cancer) hematuria occurred in over 1/3 of the testings, and in four hematuria was found on microscopic urinalysis at the time of urologic evaluation. The degree of hematuria was unrelated to the seriousness of its cause. We conclude that in this population hematuria occurs intermittently and when found, regardless of quantity or symptoms, serious underlying pathology must be ruled out. Furthermore, regular hematuria home testing offers a promising means of detecting urinary cancers and other diseases that warrant therapy in asymptomatic men 50 years of age and older.

Aged↗
PubMed1988

Evidence that subunits of type A botulinum toxin need not be linked by disulfide.

Type A neurotoxin of Clostridium botulinum strain 62A was purified by a modification of the procedure of TSE et al. (1982). Electrophoresis in sodium dodecyl sulfate - polyacrylamide gels (SDS - PAGE) indicated the mol. wt of the intact dichain molecule is 140,000 and that of its L subunit is 52,000, both expected from published values. However the mol. wt of 83,000 for the H subunit was lower than the mol. wt of 97,000 in the literature. The purified toxin separated in SDS-PAGE into H and L subunits when pretreated with 2-mercaptoethanol but it unexpectedly behaved similarly without the pretreatment. Specific toxicity (approximately 3 x 10(8) mouse LD50/mg protein) was not affected by the spontaneous molecular change that made dissociation into subunits possible. The subunits of dichain botulinum toxins are believed to be covalently joined by intersubunit disulfide(s) since they have been demonstrated only when samples are treated with 2-mercaptoethanol or dithiothreitol. Since it is not always needed, the pretreatment is apparently not reducing a disulfide that connects the subunits. The strong chelating activity also possessed by the pretreating agents suggest that the subunits may be joined by a metallic divalent cation.

Botulinum Toxins↗