Effects of low dosage pyrene pollution on biochemical characters of earthworm (Eisenia fetida) in soil

By the method of artificial soil pollution, an exposure experiment with different concentrations of pyrene (0, 60, 120, 240, 480, 960 microg x kg(-1)) was conducted to determine the cytochrome P450 and MDA contents and the glutathione-S-transferase (GST), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in earthworm gut after exposure for 1, 3, 7 and 14 days. The results indicated that within the range of test pyrene concentrations, all the biochemical indices tested differed in their sensitivity to pyrene toxicity, among which, P450 content and GST and SOD activities were most sensitive, followed by POD and CAT activities, while MDA content did not show any obvious response. Exposure duration had stronger effects than exposure dosage. In diagnosing the ecotoxicity of soil pollutant, it could be necessary to use a combined multi-time and multi-index diagnostic method to enhance the sensitivity and effectiveness of the indices adopted.

A haemodialysis exercise program using novel exercise equipment

This study explored whether an exercise programme for haemodialysis patients, including the use of a purpose built dialysis exercise machine, would improve quality of life (QoL), nutrition, physical function and biochemical indices. QoL, and biochemical indices were measured at 6 months and nutrition was measured at 12 months. Physical function was measured at 4, 8 and 12 months. Results showed improvement in physical function tests a decrease in serum phosphate. The QoL health and physical functioning domain improved also. Conclusions The development of a structured exercise programme can improve quality of life, physical functioning, PO4 levels and urea clearances of dialysis patients.

Nutrition screening by nurses in dialysis

Aims and objectives : To determine whether a nurse-completed dialysis nutritional screening tool improves referral rates for nutritional support and compare nutrition sensitive biochemical indices, mortality rates and patient-centred quality of life outcomes between referred and non-referred dialysis patients.

Background : People with chronic kidney disease requiring dialysis are nutritionally at risk. Nutrition screening has been shown to identify dialysis patients who are nutritionally at risk to refer to dietitian expertise.

Design : Prospective cluster-randomised control trial.

Methods : Monthly nurse-completed nutrition screening was completed for six consecutive months using a validated four-item instrument measuring weight change, serum phosphate, serum potassium and appetite. Participants (n = 81) were haemodialysis patients from four satellite haemodialysis centres in one Australian metropolitan health service. Primary outcome measure was rate of referral to dietetic services for nutrition support for intervention vs. control groups at six months. Secondary outcome measures were blood pressure, biochemical indices and mortality for referred vs. non-referred patients at six and nine months, and generic and dialysis-specific quality of life for referred vs. non-referred at nine months was examined.

Results : There were three times as many dietetic referrals in the intervention group than in the control group (26·3 vs. 9·3%). Serum phosphate increased significantly more in the referred patients than the non-referred patients. There were no clinically significant changes between groups in quality of life, blood pressure, mortality rates or other biochemical indices at either six or nine months.

Conclusion : Nurse-completed nutritional screening can lead to appropriate dietetic referrals for nutritional support by nutritional expert clinicians.

Relevance to clinical practice : This study is the first to demonstrate that monthly systematic nurse-completed nutritional screening can facilitate appropriate dietetic referrals that may lead to increased nutritional care for people in satellite dialysis centres.

Effect of zinc supplementation on the immune status of healthy older individuals aged 55–70 years : the ZENITH Study

Aging is associated with alterations in the immune system, effects which may be exacerbated by inadequate zinc (Zn) status. We examined the relationship between Zn status and markers of immunity and the effect of supplementation with 15 mg or 30 mg Zn/d for 6 months on immune status in healthy individuals. Zn status was assessed by dietary intake and biochemical indices. Immune status was assessed by multiple flow cytometric methods. At baseline, Zn concentration was positively associated with lymphocyte subpopulation counts and T-lymphocyte activation. Zn supplementation of 30 mg/d significantly lowered B-lymphocyte count, albeit at month 3 only. Lower doses of Zn (15 mg Zn/d) significantly increased the ratio of CD4 to CD8 T lymphocytes at month 6. Overall, these findings suggest that total Zn intake (diet plus supplementation) of up to 40 mg Zn/d do not have significant long-term effects on immune status in apparently healthy persons aged 55–70 years.

A population-based study of the effect of the HFE C282Y and H63D mutations on iron metabolism

The C282Y and H63D mutations in the HFE gene are important causes of hemochromatosis. In the elderly, these mutations might be associated with increased morbidity because of the lifelong accumulation of iron. In a population-based sample of the elderly, we determined the value of genotyping for HFE mutations to screen for subclinical hemochromatosis. HFE genotype frequencies were determined in a random group of 2095 subjects (55 years and over). In this random group, we selected within the six genotype groups a total of 342 individuals and measured their serum transferrin saturation, iron and ferritin levels. We also estimated the heritability and parameters needed to evaluate screening, including the sensitivity, specificity, positive and negative predictive values (PPV, NPV) of HFE genotypes. Iron parameters were significantly increased in subjects homozygous, heterozygous or compound heterozygous. The effect of the mutations was more pronounced in men than in women. For the H63D mutation, an allele dose effect was observed. The HFE gene explained about 5% of the variability in serum iron indices. The PPV for hemochromatosis for the C282Y homozygous was 100% in men and 67% in women. The NPV of the wild-type allele was 97% for both men and women. The sensitivity of both mutations was 70% for men and 52% for women and the specificity was 62% for men and 64% for women. Our study shows that the HFE C282Y and H63D are determinants of iron parameters in the elderly and will be effective in detecting individuals at high risk of hemochromatosis. However, when screening based on these two mutations, some individuals with subclinical hemochromatosis will be missed.

Relationship of nutritional and metabolic factors to non-invasive indices of macrovascular disease in diabetes

Factors which may account for the high frequency of macrovascular disease in diabetics are age, sex, cigarette smoking, hypertension, obesity, lack of exercise, diet, hyperglycaemia, hyperinsulinaeroia, hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol concentration, elevated free fatty acid concentration and enhanced platelet aggregation. Twenty seven (13 men and 14 women) non-insulin-dependent diabetics and thirty eight age, height and weight matched healthy subjects (10 men and 28 women) were studied. None of the subjects were smokers, or hypertensive. No subject had any clinical evidence of peripheral arterial disease, coronary heart disease or cerebrovascular disease. All had apparently normal peripheral pulses and normal ankle/arm blood pressure indices. Methods for determining arterial compliance in the segment between the left subclavian artery and each common femoral artery, and proximal resistance at the common femoral artery and posterior tibial artery, have been reviewed and developed. An appropriate food intake methodology for deriving food indices from food records was developed. Biochemical determinants have been made of glucose tolerance, glycosylated haemoglobin, serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, plasma free fatty acid and insulin. A significant decrease in the arterial compliance, and a significant increase in the arterial proximal resistance at the common femoral artery and posterior tibial artery in non-insulin-dependent diabetics, compared with their healthy controls, have been found. Significant negative correlation between arterial compliance and proximal resistance and, a significant positive correlation between the arterial proximal resistance of common femoral artery and posterior tibial artery were found. Differences between control (healthy subjects) and non-insulin-dependent diabetic groups indicate that preclinical peripheral arterial disease can be recognised even in mild diabetics by non-invasive measurement of arterial compliance or proximal resistance. There were significant and negative correlations between arterial compliance and each of blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid and plasma insulin concentration. There were significant and positive correlations between arterial proximal resistance of common femoral artery and posterior tibial artery and each of blood glucose, glycosylated haemoglobin and plasma free fatty acid concentration. Multivariate analysis to examine each of the biochemical factors Including blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid, plasma Insulin and lipids, showed that the factor which most influenced the arterial compliance and the proximal resistance of posterior tibial artery was the glucose level in the fasting state or the glucose response after a glucose load. In addition, the factors which most influenced proximal resistance of the common femoral artery were free fatty acid -level in the fasting state or glucose response after a glucose load. The factors which most influenced arterial compliance were glucose level in men, and the insulin level in the fasting state or the plasma free fatty acid response after a glucose load in women. These findings indicate that blood glucose, plasma free fatty acid and plasma insulin are risk factors for changes in arterial wall characteristic at a stage when no clinical evidence of macrovascular disease is apparent. Arterial compliance was decreased and the proximal resistance of posterior tibial artery was increased in those with a low intake of protective foods compared with those with a high intake whether healthy subjects or non-insulin-dependent diabetics. Arterial compliance was decreased in non-fish eaters compared with the fish eaters whether healthy subjects or non-insulin-dependent diabetics. Proximal resistance of the posterior tibia! artery in non-fish eaters was increased compared with fish eaters in healthy subjects. Overall, food variety, a protective food score consumption and fish consumption emerge as importance determinants of arterial wall characteristics at a stage when no clinical evidence of macrovascular disease is apparent.

Anthropometric and biochemical markers for nutritional risk among residents within an Australian residential care facility

The risk of malnutrition is high among elderly population, yet few studies have measured indicators of nutritional status among Australian aged-care residents. To determine the relationship between nutritional status and bone density, hand grip strength, and the timed-up and go test, in a group of Australian aged-care residents. Anthropometric and biochemical analysis measured in subjects recruited to be part of a six month multivitamin supplementation study. One hundred and fifteen subjects participated (68% female). The mean (SD) age and body weight was 80.2(10.6) years, and 66.5(15.0) kg, respectively. Eleven percent were underweight (body mass index, BMI, <or =20.0 kg/m(2)), and 20% were obese BMI >or =30 kg/m(2)). Low serum 25-hydroxy-vitamin D (25(OH)D, <or =50 nmol/L) concentrations were found among 79% of subjects. After adjustment for body weight, there was an association between serum 25(OH)D and bone density (heel ultrasound) (r=.204, p=.027). Low serum zinc <or =10.7 micromol/L) concentrations were found among 46% of subjects; this group had a slower timed up and go time compared with those with higher zinc concentrations (n=19, 44.6 +/- 5.6 seconds vs. n=27, 30.0 +/- 3.3 seconds, p=.020). There were no associations between nutritional markers and hand grip strength. In this group, more than (3/4) of subjects had low serum 25(OH)D, and 46% had low zinc concentrations. Serum 25(OH)D was associated a lower bone density and zinc with a slower walking time. This indicates that the elderly in long term residential care facilities are at high risk for poor nutritional status, potentially increasing morbidity and mortality.

Relationship of serum leptin to total and truncal body fat

1. In this study we investigated the relationship between serum leptin levels and body fat distribution in a random sample of women of widely ranging age and body mass index. Anthropometry and dual energy X-ray absorptiometry were used to measure body fat and its distribution.

2. Leptin levels (log transformed) were not significantly correlated with age, but were significantly positively correlated (P < 0.001) with most anthropometric measures except waist-to-hip circumference ratio. The strongest correlations were with total grams of body fat and percentage body fat (r = 0.68 and 0.76 respectively, P < 0.001). When corrected for percentage body fat the partial correlation coefficients for all other measures became non-significant. The correlation with truncal body fat fell significantly from 0.66 to - 0.05 after correction, but the partial correlation with total body fat remained significant (P < 0.005) when grams of truncal fat were controlled for (r = 0.21).

3. These results indicate that the relationship of serum leptin to percentage body fat is the strongest, and that truncal body fat, although the most metabolically active, does not appear to have an independent association with serum leptin.

Associations between dietary iron and zinc intakes, and between biochemical iron and zinc status in women

Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1) describe dietary intakes and biochemical status of iron and zinc; (2) investigate associations between dietary iron and zinc intakes; and (3) investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379). Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection), and presence of infection/inflammation using C-reactive protein (n = 326). Associations were explored using multiple regression and logistic regression. Mean (SD) iron and zinc intakes were 10.5 (3.5) mg/day and 9.3 (3.8) mg/day, respectively. Median (interquartile range) serum ferritin was 22 (12–38) μg/L and mean serum zinc concentrations (SD) were 12.6 (1.7) μmol/L in fasting samples and 11.8 (2.0) μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L) were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340). Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

Resistive vibration exercise attenuates bone and muscle atrophy in 56 days of bed rest: biochemical markers of bone metabolism

UNLABELLED: During and after prolonged bed rest, changes in bone metabolic markers occur within 3 days. Resistive vibration exercise during bed rest impedes bone loss and restricts increases in bone resorption markers whilst increasing bone formation. INTRODUCTION: To investigate the effectiveness of a resistive vibration exercise (RVE) countermeasure during prolonged bed rest using serum markers of bone metabolism and whole-body dual X-ray absorptiometry (DXA) as endpoints. METHODS: Twenty healthy male subjects underwent 8 weeks of bed rest with 12 months follow-up. Ten subjects performed RVE. Blood drawings and DXA measures were conducted regularly during and after bed rest. RESULTS: Bone resorption increased in the CTRL group with a less severe increase in the RVE group (p = 0.0004). Bone formation markers increased in the RVE group but decreased marginally in the CTRL group (p < 0.0001). At the end of bed rest, the CTRL group showed significant loss in leg bone mass (-1.8(0.9)%, p = 0.042) whereas the RVE group did not (-0.7(0.8)%, p = 0.405) although the difference between the groups was not significant (p = 0.12). CONCLUSIONS: The results suggest the countermeasure restricts increases in bone resorption, increased bone formation, and reduced bone loss during bed rest.