G D (g + d)

Distribution by Scientific Domains


Selected Abstracts


1H NMR spectroscopic method for diagnosis of malabsorption syndrome: a pilot study

NMR IN BIOMEDICINE, Issue 2 2004
Lakshmi Bala
Abstract Despite its well-documented limitations, colorimetry has been commonly used for the d -xylose test in the diagnosis of malabsorption syndrome (MAS). With a possibility of overcoming its limitations, the use of 1H NMR spectroscopy for D -xylose test is explored herein. Urine samples from 35 adults with suspected MAS were obtained before and after oral ingestion of D -xylose. The diagnosis of MAS was based on fecal fat (72,h excretion using Van de Kamer's technique, normal <,7,g/24,h and/or Sudan III stain of spot stool specimen, normal,10 droplets/high power field) and/or endoscopic duodenal biopsy. Urinary excretion of D -xylose over 5,h after consumption of 5,g D -xylose, using both colorimetry and NMR was compared (normal,1,g/5,g/5,h). In vitro experiments on the standard specimens of D -xylose were also performed independently using both methods. Colorimetry showed a lower value for the quantity of D -xylose excreted in urine than NMR [median 0.73 (0.17,1.89,g) vs 1.37 (0.17,3.23,g), respectively; p<0.0001, Wilcoxon's signed ranks test]. Colorimetry and NMR correctly diagnosed 11/12 and 10/12 (p=N.S.) patients with MAS and 14/23 and 20/23 (p<0.05) without MAS, respectively. Sensitivity and specificity of colorimetry and NMR were 91.6 and 60.7% vs 83.3 and 86.9%, respectively. In in vitro experiments, the values obtained for standard xylose using NMR showed a maximum error of 7%, whereas the colorimetric method showed 20%. The NMR method is simple and may be more accurate for the D -xylose absorption test. Colorimetry was found to be inferior as compared with NMR due to its low specificity. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Ferroportin q248h, Dietary Iron, and Serum Ferritin in Community African-Americans With Low to High Alcohol Consumption

ALCOHOLISM, Issue 11 2008
Victor R. Gordeuk
Background:, Alcohol consumption is associated with increased iron stores. In sub-Saharan Africa, high dietary ionic iron and the ferroportin Q248H allele have also been implicated in iron accumulation. We examined the associations of ferroportin Q248H, alcohol and dietary iron with serum ferritin, aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT) concentrations in African-Americans. Methods:, Inner-city African-Americans (103 men, 40 women) were recruited from the community according to reported ingestion of >4 alcoholic drinks/d or <2/wk. Typical daily heme iron, nonheme iron and alcohol were estimated using University of Hawaii's multiethnic dietary questionnaire. Based on dietary questionnaire estimates we established categories of < versus ,56 g alcohol/d, equivalent to 4 alcoholic drinks/d assuming 14 g alcohol per drink. Results:, Among 143 participants, 77% drank <56 g alcohol/d and 23%,56 g/d as estimated by the questionnaire. The prevalence of ferroportin Q248H was 23.3% with alcohol >56 g/d versus 7.5% with lower amounts (p = 0.014). Among subjects with no history of HIV disease, serum ferritin concentration had positive relationships with male gender (p = 0.041), alcohol consumption (p = 0.021) and ALT concentration (p = 0.0001) but not with dietary iron intake or ferroportin Q248H. Serum AST and ALT concentrations had significant positive associations with male gender and hepatitis C seropositivity but not with alcohol or dietary iron intake or ferroportin Q248H. Conclusions:, Our findings suggest a higher prevalence of ferroportin Q248H with greater alcohol consumption, and this higher prevalence raises the possibility that the allele might ameliorate the toxicity of alcohol. Our results suggest that alcohol but not dietary iron contributes to higher body iron stores in African-Americans. Studies with larger numbers of participants are needed to further clarify the relationship of ferroportin Q248H with the toxicity of alcohol consumption. [source]


The effect of Calluna vulgaris cover on the performance and intake of ewes grazing hill pastures in northern Spain

GRASS & FORAGE SCIENCE, Issue 4 2000
K. Osoro
The effect of the proportion of Calluna vulgaris cover on diet composition, intake and performance of sheep grazing hill vegetation communities in northern Spain is examined. A total of 591 non-lactating Gallega ewes grazed for five consecutive grazing seasons (June to September) on replicated plots of hill pastures (1700 m.a.s.l.) composed principally of Festuca, Agrostis, Nardus and Calluna spp. but with different proportions of Calluna vulgaris cover, either 0·3 (C0·3) or 0·7 (C0·7) of the total area. In 1 year, twenty-eight ewes suckling single lambs also grazed the plots. The mean stocking density over the 5 years was 8·7 ewes ha,1. On treatment C0·3, daily liveweight gains (33 g d,1) of non-lactating ewes were significantly (P < 0·001) greater than on treatment C0·7 (12 g d,1). Likewise in lactating ewes the difference in mean daily liveweight change was 40 g d,1 (,5 vs. ,45 g d,1 for C0·3 and C0·7 treatments respectively; P < 0·001). Liveweight gains of lambs were only 80,100 g d,1 from June to August and lambs only maintained live weight during August and September. The effect of lactational status on liveweight changes was not significant. Liveweight gains of non-lactating ewes increased significantly (P < 0·001) from the first to the last year of the experiment on both treatments. The composition of the diet was significantly affected by treatment (P < 0·001), with a higher proportion of grass species on the C0·3 treatment and a higher digestibility of the diet in the first half of the grazing season (P < 0·001). The proportion of C. vulgaris in the diet was significantly (P < 0·001) higher on the C0·7 treatment and increased significantly (P < 0·001) from July to September on both treatments. There were no significant differences in the composition of the diet selected by lactating and non-lactating ewes. The results demonstrate that on hill vegetation communities, in which the grass components (Festuca rubra, Agrostis capillaris, and Nardus stricta) cover at least 0·3 of the area and on which the preferred grass component (Festuca and Agrostis spp.) is maintained at a sward height of at least 2·5 cm, non-lactating ewes can increase their live weight and body condition, but this increase is influenced by the proportion and quantity of species of grass in the diet, which is affected in turn by the species of grass available and their nutritive quality. However, ewes suckling lambs were not able to maintain their live weight and body condition except when Calluna cover was 0·3 and grass height was more than 3·5 cm. It is concluded that these indigenous vegetation communities can be used in sheep production systems to complement the use of improved pastures at other times of year. In particular, they can be utilized during the non-lactating period (summer) to increase body condition before the beginning of the mating period in autumn. [source]


The beneficial role of intermediate clarification in a novel MBR based process for biological nitrogen and phosphorus removal

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2009
MinGu Kim
Abstract BACKGROUND: A novel membrane bioreactor (MBR) is described, employing an intermediate clarifier. Unlike the established function of a final clarifier in a conventional biological nutrient removal system, the role of an intermediate clarifier has rarely been studied. Thus, this work focused on explaining the fate of nutrients in the intermediate clarifier, as influenced by the hydraulic retention time (HRT) of the preceding anaerobic bioreactor. RESULTS: The system was tested with two different anaerobic/anoxic/aerobic biomass fractions of 0.25/0.25/0.5 (run 1) and 0.15/0.35/0.45 (run 2) using synthetic wastewater. The major findings of the study were that phosphorus (P) removal was affected by the role of the intermediate clarifier. In run 1, P was removed at a rate 0.16 g d,1 in the intermediate clarifier while in run 2, additional P was released at 0.49 g d,1. The nitrogen (N) removal efficiencies were 74 and 75% for runs 1 and 2 respectively, while P removal was 91 and 96%. P uptake by denitrifying phosphate accumulating organisms (DPAOs) accounted for 41,52% of the total uptake in the MBR. CONCLUSIONS: This study found that the intermediate clarifier assisted chemical oxygen demand (COD), N, and P removal. With respect to the fate of P, the intermediate clarifier functioned as an extended anaerobic zone when the HRT of the preceding anaerobic zone was insufficient for P release, and as a pre-anoxic zone when the anaerobic HRT was adequate for P release. Copyright © 2008 Society of Chemical Industry [source]


Effect of supplementation of garlic powder on rumen ecology and digestibility of nutrients in ruminants

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2008
Metha Wanapat
Abstract BACKGROUND: The present study investigated the effect of garlic powder (GAP) supplementation on rumen fermentation pattern, nutrient digestibility and intake in ruminants fed on straw as a roughage source. RESULTS: Dry matter intake and apparent digestibility of nutrients were similar among treatments. The apparent digestibility of crude protein tended to be higher in cattle supplemented with GAP compared to those fed without GAP (P = 0.08). Ruminal populations of protozoa and bacteria were decreased, as influenced by GAP supplementation. Ruminal pH and NH3 -N were similar among treatments, while blood urea nitrogen tended to be decreased (P < 0.05). Total volatile fatty acids (VFAs) were not affected by GAP supplementation but individual VFAs were significantly different (P < 0.05), especially C3; meanwhile, C2:C3 ratio was reduced by GAP supplementation (P < 0.05). In addition, N balances were significantly increased as level of GAP supplementation increased and was highest at 120 g d,1 GAP. CONCLUSION: Results of this study suggest that feeding of GAP at 80 g d,1 with urea-treated rice straw could enhance ruminal propionate production and thus lower C2:C3 ratio, decreasing the protozoal population, as well as increasing N retention and absorption in ruminants. Copyright © 2008 Society of Chemical Industry [source]


Dietary fat plays a major role in obesity: no

OBESITY REVIEWS, Issue 2 2002
W. C. Willett
Summary The percentage of dietary energy from fat has been suggested to be an important determinant of body fat, and this presumed effect has been invoked to justify the general promotion of low-fat diets. Dietary fat and the prevalence of obesity are lower in poor countries than in affluent countries. However, these contrasts are seriously confounded by differences in physical activity and food availability; within areas of similar economic development, per capita intake of fat and the prevalence of obesity have not been positively correlated. Randomized trials are the preferable method for evaluating the effect of dietary fat on adiposity because they avoid problems of confounding that are difficult to control in other studies. In short-term trials, a small reduction in body weight is typically seen in individuals randomized to diets with a lower percentage of calories from fat. In a meta-analysis of these trials, it was estimated that a decrease in 10% of energy from fat would reduce weight by 16 g d,1, which would correspond to a 9-kg weight loss by 18 months. However, compensatory mechanisms appear to operate because in trials lasting one year or longer, fat consumption within the range of 18,40% of energy has consistently had little, if any, effect on body fatness. Moreover, within the United States (US), a substantial decline in the percentage of energy from fat during the last two decades has corresponded with a massive increase in obesity, and similar trends are occurring in other affluent countries. Diets high in fat do not account for the high prevalence of excess body fat in Western countries; reductions in the percentage of energy from fat will have no important benefits and could further exacerbate this problem. The emphasis on total fat reduction has been a serious distraction in efforts to control obesity and improve health in general. [source]