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Biomedical subjects

D I Thurnham

Publications and source records attributed to D I Thurnham.

At least 19 recordsLinked to original sources
PubMed2001

Dialysis and gel filtration of isolated low density lipoproteins do not cause a significant loss of low density lipoprotein tocopherol and carotenoid concentration.

The resistance of isolated low density lipoprotein (LDL) to copper-initiated oxidation is often used as a measure of effectiveness of an antioxidant intervention. Prior to oxidation, excess salt and EDTA are removed via dialysis or gel filtration of the LDL sample. However, there is concern over whether the antioxidant content of dialyzed or gel-filtered LDL is truly representative of native LDL extracted from a blood sample. Previously, the experiments done after the storage of native and dialyzed LDL at -80 degrees C showed that the dialysis step can cause a loss of up to 60% in the tocopherol and carotenoid content of LDL. In the present study, a comparison of the micronutrient concentration in freshly prepared dialyzed and native LDL from 35 subjects showed that after the correction for cholesterol, only lycopene (13%, P < 0.001) and to a lesser extent alpha-carotene (8%, P < 0.02) were significantly decreased, and the absolute fall in concentration was far smaller than previously reported. Other experiments done with smaller numbers of samples suggested that there were minimal micronutrient losses following gel filtration and that it was important to include 10 micromol/L EDTA in the dialysis and elution buffer; otherwise micronutrient losses did occur. In summary, immediate dialysis of freshly isolated LDL in the presence of 10 micromol/L EDTA does not cause any major loss in the concentration of tocopherol and most carotenoids.

Carotenoids↗
PubMed2001

Serum concentrations of carotenoids and vitamins A, E, and C in control subjects from five European countries.

High intakes of fruits and vegetables, or high circulating levels of their biomarkers (carotenoids, vitamins C and E), have been associated with a relatively low incidence of cardiovascular disease, cataract and cancer. Exposure to a high fruit and vegetable diet increases antioxidant concentrations in blood and body tissues, and potentially protects against oxidative damage to cells and tissues. This paper describes blood concentrations of carotenoids, tocopherols, ascorbic acid and retinol in well-defined groups of healthy, non-smokers, aged 25-45 years, 175 men and 174 women from five European countries (France, UK (Northern Ireland), Republic of Ireland, The Netherlands and Spain). Analysis was centralised and performed within 18 months. Within-gender, vitamin C showed no significant differences between centres. Females in France, Republic of Ireland and Spain had significantly higher plasma vitamin C concentrations than their male counterparts. Serum retinol and alpha-tocopherol levels were similar between centres, but gamma-tocopherol showed a great variability being the lowest in Spain and France, and the highest in The Netherlands. The provitamin A: non-provitamin A carotenoid ratio was similar among countries, whereas the xanthophylls (lutein, zeaxanthin, beta-cryptoxanthin) to carotenes (alpha-carotene, beta-carotene, lycopene) ratio was double in southern (Spain) compared to the northern areas (Northern Ireland and Republic of Ireland). Serum concentrations of lutein and zeaxanthin were highest in France and Spain; beta-cryptoxanthin was highest in Spain and The Netherlands; trans-lycopene tended to be highest in Irish males and lowest in Spanish males; alpha-carotene and beta-carotene were higher in the French volunteers. Due to the study design, the concentrations of carotenoids and vitamins A, C and E represent physiological ranges achievable by dietary means and may be considered as 'reference values' in serum of healthy, non-smoking middle-aged subjects from five European countries. The results suggest that lutein (and zeaxanthin), beta-cryptoxanthin, total xanthophylls and gamma-tocopherol (and alpha- : gamma-tocopherol) may be important markers related to the healthy or protective effects of the Mediterranean-like diet.

Adult↗
PubMed2001

A European carotenoid database to assess carotenoid intakes and its use in a five-country comparative study.

A food frequency questionnaire (FFQ) and carotenoid database with information on alpha- and beta-carotene, lutein, lycopene and beta-cryptoxanthin was prepared and used to compare the carotenoid intakes in five European countries: UK, Republic of Ireland, Spain, France and The Netherlands. Eighty, age- (25-45 years) and sex-matched volunteers were recruited in each of the five countries. A FFQ and carotenoid database was prepared of the most commonly consumed carotenoid rich foods in the participating countries and the information was used to calculate frequency and intake of carotenoid-rich foods. The median total carotenoid intake based on the sum of the five carotenoids, was significantly higher (P < 0.05) in France (16.1 mg/day) and lower in Spain (9.5 mg/day,) than the other countries, where the average intake was approximately 14 mg/day. Comparison of dietary source of carotenoids showed that carrots were the major source of beta-carotene in all countries except Spain where spinach was most important. Likewise, carrots were also the main source of alpha-carotene. Tomato or tomato products, were the major source of lycopene. Lutein was mainly obtained from peas in Republic of Ireland and the UK, however, spinach was found to be the major source in other countries. In all countries, beta-cryptoxanthin was primarily obtained from citrus fruit. Comparing the data with that from specific European country studies suggests that the FFQ and carotenoid database described in the present paper can be used for comparative dietary intake studies within Europe. The results show that within Europe there are differences in the specific intake of some carotenoids which are related to different foods consumed by people in different countries.

Adult↗
PubMed2000

Consumption of tomato products with olive oil but not sunflower oil increases the antioxidant activity of plasma.

Health benefits of lycopene from tomato products have been suggested to be related to its antioxidant activity. Dietary fat may influence the absorption and hence the plasma levels and antioxidant activity of lycopene. In the present study, we have compared the effect of consumption of tomato products with extra-virgin olive oil vs. tomato products plus sunflower oil on plasma lycopene and antioxidant levels. Results show that the oil composition does not affect the absorption of lycopene from tomato products because similar levels of plasma lycopene (mean +/- SD) were obtained on feeding tomatoes (providing approximately 46 mg lycopene/d) for 7 d with either olive oil (0.66 +/- 0.26 vs 1.20 +/- 0.20 micromol/l, p <.002) or sunflower oil (0.67 +/- 0.27 vs. 1.14 micromol/l, p <.001). However, consumption of tomato products with olive oil significantly raised the plasma antioxidant activity (FRAP) from 930 +/- 150 to 1118 +/- 184 micromol/l, p <.01) but no effect was observed when the sunflower oil was used. The change (supplementation minus start values) in FRAP following the consumption of tomato products with oil was significantly higher for olive oil (190 +/- 101) than for sunflower oil (-9.6 +/- 99, p <. 005). In conclusion, the results of the study show that consumption of tomato products with olive oil but not with sunflower oil improves the antioxidant activity of the plasma.

Adult↗
PubMed2000

Frequency of fruit and vegetable consumption and blood antioxidants in the Caerphilly cohort of older men.

OBJECTIVE: To assess the number of portions of fruit and vegetables consumed daily by a large representative sample of older men, and to determine how blood antioxidant (vitamins E, A and carotenoids) concentrations vary with fruit and vegetable consumption. DESIGN: Cross-sectional study of free-living men. SUBJECTS: Men aged 55-69 y (dietary data, n=1957; blood data, n=1874) participating in Phase III (1989-1993) of the Caerphilly and Speedwell Collaborative Heart Disease Studies. METHODS: Dietary data were obtained by semi-quantitative food-frequency questionnaire and blood samples were analysed for antioxidant vitamins. Men were subdivided into groups on the basis of portions per day of fruit and vegetables. Within these sub-groups, mean and 95% ranges of intakes and of blood antioxidant levels were obtained. Log transformations were performed where appropriate. RESULTS: Only 4.3% of the men met the recommended target of five portions, while 33.3% of the men consumed one or fewer portions of fruit and vegetables per day. Those men who consumed the poorest diets with respect to fruit and vegetable intakes were more likely to be from lower socio-economic classes, drink more alcohol and be current smokers. Fruit and vegetable intake reflected plasma concentrations of antioxidants, which showed a dose-response relationship to frequency of consumption. CONCLUSIONS: Older men in the UK consume much less fruit and vegetables than current recommendations. Major difficulties are likely to be encountered in trying to meet a dietary target that is clearly much higher than the fruit and vegetable consumption of large sections of the older population in the UK. SPONSORSHIP: This work was supported by the Medical Research Council.

Aged↗
PubMed2000

Innate immunity, gut integrity, and vitamin A in Gambian and Indian infants.

Gut integrity, which can be measured by the urinary lactulose:mannitol excretion test, deteriorates with the introduction of weaning foods. In The Gambia, gut integrity measured monthly over 15 months in 119 infants (aged 2-15 months) was least impaired from April to June. This coincides with the time of year of maximum vitamin A (VA) intake-the mango season. Subsequently, two VA intervention studies were done in infants in India. Eighty infants attending a community health center received 16,700 IU weekly or placebo. In another study, 94 hospitalized infants were given 200, 000 IU VA or placebo: 31 received VA on admission, while the rest (32 VA, 31 placebo) received treatment on discharge. All VA-treated groups had more rapid improvement in gut integrity than the placebo groups, but no group had gut integrity normalized by Western standards. The data suggest that VA status may influence gut integrity.

Child, Hospitalized↗
PubMed2000

Interpretation of vitamin A status in apparently healthy Pakistani children by using markers of subclinical infection.

BACKGROUND: Plasma retinol concentrations are depressed by infection but are commonly used to assess vitamin A status. OBJECTIVE: We measured 2 acute phase proteins, alpha(1)-antichymotrypsin (ACT) and alpha(1)-acid glycoprotein (AGP), to determine whether they could be used to assist in interpreting vitamin A status. DESIGN: In 1997, a 2-stage cluster-sampling procedure was used to select 3074 apparently healthy, 6-60-mo-old children from rural and urban areas of North West Frontier Province, Pakistan. Plasma retinol, ACT, AGP, and ferritin measurements and anthropometric measurements were obtained for 2519 children. RESULTS: Median plasma retinol, ACT, AGP, and ferritin concentrations were 0.86 micromol/L, 0.39 g/L, 1.14 g/L, and 5.5 microg/L, respectively. There were no significant (P: > 0.05) differences in retinol, ACT, or AGP by sex or age. Some 797 children (32%) had retinol concentrations <0.7 micromol/L and 87 (4%) had retinol concentrations <0.35 micromol/L; 274 children (11%) had elevated ACT (>0.6 g/L) and 1141 (45%) had elevated AGP (>1.2 g/L). Retinol concentration correlated with ACT (r = -0.141), AGP (r = -0.138), and ferritin (r = -0.09) (all P: < 0.001), but stepwise multiple regression indicated that these 3 variables made a minimal although quantifiable contribution to the variance of retinol (ACT, r(2) = 0.02; all 3 variables, r(2) = 0.03). CONCLUSIONS: The transient depression in plasma retinol produced by subclinical infection increased the number of at-risk children by 10% (76 of 797) and 56% (49 of 87) for plasma retinol concentrations <0.7 and <0.35 micromol/L, respectively. In addition, dietary inadequacy may be responsible for retinol concentrations being approximately 16% lower in Pakistani children than in children in the United Kingdom, where dietary vitamin A is adequate.

Biomarkers↗
PubMed2000

Nonalcoholic red wine extract and quercetin inhibit LDL oxidation without affecting plasma antioxidant vitamin and carotenoid concentrations.

BACKGROUND: Antioxidant enrichment of LDL can increase its resistance to oxidation and hence reduce its atherogenicity. The objective of the present study was to investigate whether in vivo supplementation with nonalcoholic red wine extract and quercetin can increase the oxidative resistance of LDL, and also whether the supplementation has any effect on other antioxidative micronutrients present in the blood. METHODS: Twenty-one male subjects were supplemented with a placebo drink for 2 weeks and randomized into two groups. One group (n = 11) received the red wine extract (1 g/day, equivalent to 375 mL of red wine) and the other group (n = 10) quercetin (30 mg/day) for 2 weeks, followed by a 5-week washout period. RESULTS: In the red wine extract-supplemented group, ex vivo copper-initiated oxidation of LDL (lag phase, mean +/- SD) was 40 +/- 11 min at the baseline, and increased significantly to 47 +/- 6 min [P <0.05 compared with placebo (38 +/- 4 min) and the washout values (40 +/- 5 min)]. In the quercetin-supplemented group, the lag phase was 44 +/- 11 and 40 +/- 5 min for the baseline and placebo, respectively, and increased significantly to 51 +/- 7 min [P <0.05 compared with placebo and washout (41 +/- 9 min)] after supplementation. Plasma lipids (triglycerides, total cholesterol, LDL- and HDL-cholesterol) did not change during the study period. Supplementation with red wine extract or quercetin had no effect on plasma vitamin C and E, retinol, and carotenoid concentrations. CONCLUSIONS: Alcohol-free red wine extract and one of its components, quercetin, can inhibit LDL oxidation after in vivo supplementation; such "inhibition" is unrelated to changes in antioxidant vitamin and carotenoid concentrations.

Adult↗
PubMed2000

Influence of increased fruit and vegetable intake on plasma and lipoprotein carotenoids and LDL oxidation in smokers and nonsmokers.

BACKGROUND: Epidemiological studies suggest a cardioprotective role for carotenoid-rich foods. Smokers have a high risk of cardiovascular disease and low dietary intake and plasma concentrations of carotenoids. The aim of this study was to determine the carotenoid response of smokers and nonsmokers to increased intake of 300-400 g of vegetables and its effect on LDL oxidation. METHODS: After a depletion period of 8 days, 34 healthy females (18 nonsmokers, 16 smokers) were supplemented with beta-carotene- and lutein-rich (green) and lycopene-rich (red) vegetable foods, each for 7 days. RESULTS: Baseline concentrations (mean +/- SD) of plasma beta-carotene (0.203+/-0.28 micromol/L vs. 0.412+/-0.34 micromol/L; P <0.005) and lutein (0.180 +/-0.10 vs. 0.242+/-0.11 micromol/L; P<0.05) but not lycopene (0.296+/-0.10 vs. 0.319+/-0.33 micromol/L) were significantly lower in smokers compared with nonsmokers. After supplementation, the change (supplementation minus depletion) in plasma beta-carotene (0.152+/- 0.43 vs. 0.363+/-0.29 micromol/L in smokers vs. nonsmokers; P = 0.002) and LDL lutein (0.015+/-0.03 vs. 0.029+/-0.03 micromol/mmol cholesterol; P = 0.01) was significantly lower in smokers than nonsmokers. Green-vegetable supplementation had no effect on the resistance of LDL to oxidation (lag-phase) in either group. After red-vegetable supplementation, plasma and LDL lycopene concentrations were increased in both groups, but only nonsmokers showed a significant increase in the lag-phase (44.9+/-9.5 min at baseline, 41.4+/-6.5 min after depletion, and 49.0+/-8.9 min after supplementation; P<0.01) compared with depletion. CONCLUSIONS: In this short-term intervention study, a dietary intake of >40 mg/day of lycopene by a group of nonsmoking individuals significantly reduced the susceptibility of LDL to oxidation, whereas an equivalent increase in lycopene by a group of smokers showed no such effect.

Adult↗
PubMed1999

The effect of vitamin A on epithelial integrity.

Vitamin A is the generic term for a variety of fat-soluble substances including retinol, retinyl palmitate and the provitamin A carotenoids such as all-trans-beta-carotene. Vitamin A is commonly known as the anti-infective vitamin and has an essential role in vision and cellular differentiation, the latter providing a unique core mechanism helping to explain the influence of vitamin A on epithelial barriers. Alterations in the epithelial lining of vital organs occur early in deficiency, suggesting a potentially important role for the barrier function. Vitamin A deficiency (VAD) is most commonly recognized in the eye. The conjunctival-impression cytology test detects the presence of larger irregular keratinized cells and the absence of mucous-secreting goblet cells, indicative of VAD. The method is simple, quick and sensitive in populations where VAD is present. In the respiratory tract, observational studies all show an association with VAD, although vitamin A supplementation studies appear to have little effect on respiratory disease. Organ-specific targeting may improve success rates. The dual-sugar intestinal-permeability test allows the effect of vitamin A supplementation to be monitored on the gastrointestinal tract. Two vitamin A supplementation studies were carried out recently in Orissa State, India. Healthy infants of weaning age were administered orally eight weekly doses of 5.0 mg retinol equivalents and hospitalized infants received one large oral dose 60 mg retinol equivalents in the form of retinyl palmitate. Improvements in gut integrity and haematological status were observed in both studies. In summary, the response of the eye to vitamin A supplementation is well established; the present review highlights some of the more recent observations examining the effects of vitamin A.

Dietary Supplements↗
PubMed1999

Optimal nutrition: vitamin A and the carotenoids.

There are two major dietary sources of vitamin A: easily absorbed retinyl palmitate in foods of animal origin, and poorly bioavailable carotenoids from plant foods. Plasma retinol is tightly controlled, probably by regulation of retinol-binding protein (RBP) formation in the liver, and only hormonal factors (e.g. oral contraceptives) and infection will alter the homeostasis. Delivery of retinol to the tissues is facilitated by the RBP-retinol complex; however, there is evidence that this mechanism can be bypassed when very high doses of vitamin A are given. Some retinyl ester may be released to tissues from chylomicrons when the latter bind to tissue lipoprotein receptors during their passage from the gut to the liver following a meal. High-dose vitamin A therapy is a means of rapidly improving vitamin A status in persons with sub-optimal vitamin A nutrition but there are dangers of toxic symptoms (e.g. teratogenicity) from excess vitamin A usage. Evidence is presented to suggest that the plasma retinol: RBP may be a guide to optimal vitamin A status, since values less than one frequently occur in less-developed countries and during infection. In contrast to plasma retinol, plasma carotenoids reflect the dietary intake of plant foods. However, absorption is limited by poor bioavailability and a saturable uptake mechanism in competition with other phytochemicals. Recent work on bioavailability suggests that the calculation of plant food vitamin A activity should be re-examined. Illness has little influence on plasma levels except by suppressing appetite. Carotenoids are generally regarded as non-toxic yet intervention studies with beta-carotene in smokers have been associated with increased lung cancer and heart disease. Some carotenoids are important as vitamin A precursors, but the physiological importance of their antioxidant properties is not known and consequently the amount needed for optimal nutrition is uncertain.

Absorption↗
PubMed1999

Antioxidants and lipoprotein metabolism.

Lipoprotein metabolism plays a significant role in the pathogenesis of atherosclerosis and risk of vascular disease. Elevated levels of LDL and low levels of HDL are linked to the risk of cardiovascular disease. It is now widely accepted that oxidative modification of LDL affects the metabolism of lipoproteins, leading to their increased accumulation in arterial intima. The present paper will examine some of the accumulating evidence from studies showing relationships between dietary intake of antioxidant nutrients, i.e. vitamins E and C, the carotenoids and the flavonoids, and their influence on lipoprotein metabolism. In particular, the present paper will review the available literature on the affect of antioxidant supplementation on lipoprotein oxidation, and hence metabolism of LDL in human subjects.

Antioxidants↗
PubMed1999

Antioxidant enzymes, inflammatory indices and lifestyle factors in older men: a cohort analysis.

We examined the relationship between blood antioxidant enzyme activities, indices of inflammatory status and a number of lifestyle factors in the Caerphilly prospective cohort study of ischaemic heart disease. The study began in 1979 and is based on a representative male population sample. Initially 2512 men were seen in phase I, and followed-up every 5 years in phases II and III; they have recently been seen in phase IV. Data on social class, smoking habit, alcohol consumption were obtained by questionnaire, and body mass index was measured. Antioxidant enzyme activities and indices of inflammatory status were estimated by standard techniques. Significant associations were observed for: age with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin, both protein and oxidase (p < 0.0001); smoking habit with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin, both protein and oxidase (p < 0.0001) and with glutathione peroxidose (GPX) (p < 0.0001); social class with alpha-1-antichymotrypsin (p < 0.0001), with caeruloplasmin both protein (p < 0.001) and oxidase (p < 0.01) and with GPX (p < 0.0001); body mass index with alpha-1-antichymotrypsin (p < 0.0001) and with caeruloplasmin protein (p < 0.001). There was no significant association between alcohol consumption and any of the blood enzymes measured. Factor analysis produced a three-factor model (explaining 65.9% of the variation in the data set) which appeared to indicate close inter-relationships among antioxidants.

Acute-Phase Proteins↗
PubMed1998

A 3-month, double-blind, controlled trial of feeding with sucrose polyester in human volunteers.

Sucrose polyester (SPE) is a tasteless, odourless substance which reduces plasma cholesterol concentrations and may therefore be valuable as a fat substitute in human foodstuffs. It has recently been approved for use in snack foods by the United States Federal Drug Administration. The current study was designed to investigate its effects on gastrointestinal physiology and nutrient absorption in human subjects. A 6-month (2 x 3-month periods) double-blind, placebo-controlled, randomized, cross-over trial of SPE and control fat was performed in healthy free-living volunteers. Subjects consumed 20-40 g of SPE daily (mean 26.8 (SE 6.8) g) which reduced the intake of total and saturated fat but had no effect on energy intake or body weight. Plasma cholesterol and triacylglycerols were reduced. The frequency of bowel movements and their urgency were increased and anal leakage occurred in 7.2% of subjects. Abdominal pain was more frequent in subjects receiving SPE and was significantly greater than in the control group after 8 weeks feeding. The plasma concentrations of vitamin E and six carotenoids were significantly reduced. Routine haematology and biochemistry, other vitamins, intestinal biopsies, bile-salt retention, rectal prostaglandins, fractional Ca absorption and aminopyrine metabolism were unaffected. The ingestion of foods containing 20-40 g SPE daily provoked significant gastrointestinal problems. This intake is greater than that to be expected from the use of SPE in savoury snack foods, for which it has been approved by the United States Federal Drug Administration. However, the favourable effects on lipid profiles must be balanced against the reduction in the concentrations of vitamins and carotenoids, as these compounds may have beneficial effects on health through protection from free-radical oxidative stress.

Adult↗
PubMed1998

Intestinal absorption of beta-carotene, lycopene and lutein in men and women following a standard meal: response curves in the triacylglycerol-rich lipoprotein fraction.

A high intake of fruit and vegetables is believed to be protective against heart disease and cancer. beta-Carotene has been closely examined for evidence of these protective properties but evidence is still conflicting and there are many other carotenoids in plant foods which deserve attention. This paper reports studies on the concentrations of lutein and lycopene in the triacylglycerol-rich lipoprotein (TRL) fraction of plasma in comparison with beta-carotene following a large dose of the respective carotenoids fed with a standard meal after an overnight fast. beta-Carotene (40 mg) was given to twelve volunteers (six men and six women) and six of the same volunteers (three men and three women) also received 31.2 mg lutein or 38 mg lycopene. Plasma was collected at hourly intervals for 8 h and the TRL fraction was separated and subsequently analysed for the respective carotenoids and retinyl palmitate in the case of beta-carotene. Intestinal uptake of the three carotenoids was estimated using the 'area under the curve' method and apparent absorption was calculated from these results. The response curves in the TRL fraction for beta-carotene and retinyl palmitate occurred maximally over the fourth to fifth hour postprandially. There was a correlation between the TRL concentrations of beta-carotene and retinyl palmitate (males r 0.62, P < 0.001; females r 0.52, P < 0.001) and there was no significant difference between men and women either in the total amount of beta-carotene appearing in the TRL fraction or in the amount converted to retinol. On estimation, approximately 1.4 mg of the 40 mg beta-carotene dose was absorbed and this was not significantly different from the amount of lycopene (1.0 mg) but significantly different (P < 0.05) from the amount of lutein (0.8 mg) absorbed, after correction for the smaller doses administered. There was approximately a twofold difference between subjects in the uptake of beta-carotene into the TRL fraction, a two- to threefold variation in lycopene and a two- to threefold variation in lutein. Despite these inter-subject differences, in three volunteers between whom there was a threefold difference in beta-carotene in the TRL fraction and a twofold difference in retinol formation, repeat experiments with beta-carotene 4 months later found differences of only 3-6% in the TRL beta-carotene content and 4-9% for the TRL retinol formed. In conclusion, large inter-subject variation in TRL carotene uptake precluded any differences between sexes but surprising intra-subject consistency was observed in TRL beta-carotene uptake of three subjects.

Adult↗
PubMed1998

Glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities in riboflavin-deficient rats infected with Plasmodium berghei malaria.

Riboflavin deficiency interferes with the growth and multiplication of malaria parasites as well as the host response to malaria. The objective of the present work was to determine the effects of riboflavin deficiency on erythrocyte glutathione peroxidase (EC 1.11.1.9; GPx) and superoxide dismutase (EC 1.15.1.1; SOD) in rats infected with Plasmodium berghei malaria. Riboflavin in its co-enzyme form, FAD, is required by glutathione reductase (EC 1.6.4.1) to regenerate GSH and GSH is an important cellular antioxidant both in its own right and also as a substrate for the enzyme GPx. Weanling rats were deprived of riboflavin for 8 weeks before intraperitoneal injection of 1 x 10(6) P. berghei parasites. Control animals were weight-matched to the respective riboflavin-deficient group. At 10 d post-infection, parasite counts were higher in the weight-matched control group than the riboflavin-deficient group (P = 0.004). GPx activity was higher in erythrocytes of rats parasitized with P. berghei than comparable non-infected rats regardless of riboflavin status (P < 0.05). As mature erythrocytes do not synthesize new protein, the higher GPx activities were probably due to the presence of the parasite protein. In erythrocytes from riboflavin-deficient rats, GPx activity tended to be lower than in those rats fed on diets adequate in riboflavin (weight-matched controls) whether parasitized or not, but the difference was not significant. Neither riboflavin deficiency nor malaria had any effect on erythrocyte SOD activity. It was concluded that riboflavin deficiency has no marked effect on erythrocyte GPx or SOD activity in the rat.

Animals↗
PubMed1998

Impact of health service provision on mothers and infants in a rural village in North West Frontier Province, Pakistan.

OBJECTIVE: The objective of this paper is to examine the impact of the Health Service Research Project of the Pakistan Medical Research Council (PMRC) on mothers and infants in Budhni village, North West Frontier Province (NWFP), Pakistan. METHODS: Information from the PMRC records on the socioeconomic and demographic situation over the last 10 years and anthropometric measurements made on all infants from 1986-96 were collected and analysed. RESULTS: The demographic data showed a number of changes, namely a reduction in birth rate and improvements in perinatal, neonatal, infant and child mortality rates. Literacy in the village was poor (27 and 39% literate in 1986 and 1996, respectively) and female literacy showed no improvement (14%). Improvements in sanitation and in the water supply introduced by the PMRC had limited success, as clean water was subsequently contaminated by unclean hands and utensils, and 50% of the population continued to use open fields for sanitation. In 1986 only 27% of children 0-5 years were vaccinated, but by 1996, 96% of children had completed polio, diphtheria/pertussis/tetanus (DPT) and bacille Calmette-Guérin (BCG) vaccination programmes and 95% of women of child-bearing age were vaccinated against tetanus. Protection against tetanus reduced neonatal deaths and from 1993 onwards there have been no further cases. Anthropometric data for the period 1986-96 for infants (0-24 months) showed that at birth the majority of infants were close to the 50th National Centre for Health Statistics (NCHS) centile for weight and length, and only 5% of birth-weights were less than 2.5 kg. Growth charts showed faltering in length and weight and by 24-months length in both boys and girls was below the 3rd NCHS centile and weights were just above. CONCLUSIONS: Reductions in child mortality have occurred over the period 1986-96. However, the slow progress in adopting hygienic practices, despite health education, and the low literacy rates, particularly in women, may hamper continued improvement.

Adolescent↗