Aluminum tolerance genes on the short arm of chromosome 3R are linked to organic acid release in triticale.
(41/1696)
Triticale, a hybrid between wheat and rye, shows a high degree of Al tolerance that is inherited from rye, but the mechanisms of high Al tolerance in both rye and triticale are unknown. We found that the short arm of chromosome 3R carries genes necessary for Al tolerance in triticale (x Triticosecale Wittmark cv Currency). Detailed comparative studies with a 3DS.3RL translocation line (ST22) and a non-substitution line (ST2) were conducted. Root elongation was similarly inhibited by Al in ST2 and ST22 during the first 12 h of Al treatment, but more strongly in ST22 than in ST2 at 18 h and thereafter. The root inhibition induced by other metals (Cu, Cd, and La) was similar between ST2 and ST22, suggesting that the action of the genes for Al tolerance on the short arm of triticale chromosome 3R is highly specific to Al. A 2-fold larger amount of malate and citrate was released from the roots of ST2 than from ST22 at 12 and 18 h after Al treatment, respectively. The marked lag phase in the inhibition of root elongation and the release of organic acids implies that the expression of genes on the short arm of triticale chromosome 3R is induced by Al, and that these genes are necessary for the release of organic acids. (+info)
Carbohydrates, dietary fiber, and incident type 2 diabetes in older women.
(42/1696)
BACKGROUND: Dietary carbohydrates may influence the development of type 2 (non-insulin-dependent) diabetes, for example, through effects on blood glucose and insulin concentrations. OBJECTIVE: We examined the relations of baseline intake of carbohydrates, dietary fiber, dietary magnesium, and carbohydrate-rich foods and the glycemic index with incidence of diabetes. DESIGN: This was a prospective cohort study of 35988 older Iowa women initially free of diabetes. During 6 y of follow-up, 1141 incident cases of diabetes were reported. RESULTS: Total grain, whole-grain, total dietary fiber, cereal fiber, and dietary magnesium intakes showed strong inverse associations with incidence of diabetes after adjustment for potential nondietary confounding variables. Multivariate-adjusted relative risks of diabetes were 1.0, 0.99, 0.98, 0.92, and 0.79 (P for trend: 0.0089) across quintiles of whole-grain intake; 1.0, 1.09, 1.00, 0.94, and 0.78 (P for trend: 0.005) across quintiles of total dietary fiber intake; and 1.0, 0.81, 0.82, 0.81, and 0.67 (P for trend: 0.0003) across quintiles of dietary magnesium intake. Intakes of total carbohydrates, refined grains, fruit and vegetables, and soluble fiber and the glycemic index were unrelated to diabetes risk. CONCLUSION: These data support a protective role for grains (particularly whole grains), cereal fiber, and dietary magnesium in the development of diabetes in older women. (+info)
Mediterranean diet and age with respect to overall survival in institutionalized, nonsmoking elderly people.
(43/1696)
BACKGROUND: In studies from Italy and Greece, a Mediterranean dietary pattern was shown to favorably affect life expectancy in the elderly population. This pattern is thought to reduce the risk of cancer in addition to being cardioprotective. OBJECTIVE: The objective of this study was to evaluate the interactive effects of the Mediterranean diet and age with respect to survival after controlling for several other variables that could be considered as confounders: age, sex, body mass index, albumin concentration, physical activity, self-assessment of health, and dieting in response to chronic conditions. DESIGN: This was a cohort study involving 161 nonsmoking elderly subjects (74 subjects aged <80 y and 87 subjects aged > or =80 y) living in Spain. The subjects were followed up for > or =9 y. Diet was assessed with a semiquantitative food-frequency questionnaire. RESULTS: A diet score based on 8 characteristics of the traditional diet in the Mediterranean region was associated with a significant reduction in overall mortality in elderly subjects aged <80 y but not in subjects aged > or =80 y. A unit increase in the diet score predicted a 31% reduction in mortality in subjects aged <80 y (95% CI: 7%, 57%). CONCLUSION: Efforts to promote adherence to the Mediterranean dietary pattern appear to be worthwhile in persons aged <80 y, in whom the diet predicts survival, but we do not have any available evidence that such a diet benefits subjects aged > or =80 y. (+info)
Lack of effect of a high-fiber cereal supplement on the recurrence of colorectal adenomas. Phoenix Colon Cancer Prevention Physicians' Network.
(44/1696)
BACKGROUND: The risks of colorectal cancer and adenoma, the precursor lesion, are believed to be influenced by dietary factors. Epidemiologic evidence that cereal fiber protects against colorectal cancer is equivocal. We conducted a randomized trial to determine whether dietary supplementation with wheat-bran fiber reduces the rate of recurrence of colorectal adenomas. METHODS: We randomly assigned 1429 men and women who were 40 to 80 years of age and who had had one or more histologically confirmed colorectal adenomas removed within three months before recruitment began to a supervised program of dietary supplementation with either high amounts (13.5 g per day) or low amounts (2 g per day) of wheat-bran fiber. The primary end point was the presence or absence of new adenomas at the time of follow-up colonoscopy. Subjects and physicians, including colonoscopists, were unaware of the group assignments. RESULTS: Of the 1303 subjects who completed the study, 719 had been randomly assigned to the high-fiber group and 584 to the low-fiber group. The median times from randomization to the last follow-up colonoscopy were 34 months in the high-fiber group and 36 months in the low-fiber group. By the time of the last follow-up colonoscopy, at least one adenoma had been identified in 338 subjects in the high-fiber group (47.0 percent) and in 299 subjects in the low-fiber group (51.2 percent). The multivariate adjusted odds ratio for recurrent adenoma in tile high-fiber group, as compared with the low-fiber group, was 0.88 (95 percent confidence interval, 0.70 to 1.11; P=0.28), and the relative risk of recurrence according to the number of adenomas, in the high-fiber group as compared with the low-fiber group, was 0.99 (95 percent confidence interval, 0.71 to 1.36; P=0.93). CONCLUSIONS: As used in this study, a dietary supplement of wheat-bran fiber does not protect against recurrent colorectal adenomas. (+info)
Similarity and divergence among viruses in the genus Furovirus.
(45/1696)
Nucleotide sequences of RNAs 1 and 2 of a Japanese strain of soil-borne wheat mosaic virus (SBWMV), the type species of the genus Furovirus, and sorghum chlorotic spot virus (SCSV) were determined from cloned cDNA. The relationship among the Japanese and US strains of SBWMV, SCSV, oat golden stripe virus (OGSV), and recently proposed Chinese wheat mosaic and European wheat mosaic viruses (CWMV and EWMV) were examined at the nucleotide and amino acid levels. Pairwise comparisons of genome-encoded proteins among the six viruses showed that the US strains of SBWMV and CWMV were the most closely related pair in RNA 1 and the Japanese strains of SBWMV and EWMV were most closely related in RNA 2. SCSV was most distantly related to the other five viruses. Phylogenetic analysis indicated that there may have been an ancient reassortment between RNAs 1 and 2 of the four wheat-infecting viruses and OGSV, while SCSV was shown to have separated from the rest before the other five viruses diverged. The fact that CWMV and EWMV have almost identical biological properties as well as the sequence similarities to the two strains of SBWMV suggests that they be regarded as strains of SBWMV, considering that SBWMV consists of genetically diverged strains. OGSV and SCSV are distinct in biological properties in addition to genetic divergence in the genus Furovirus. (+info)
A highly digestible sorghum mutant cultivar exhibits a unique folded structure of endosperm protein bodies.
(46/1696)
The endosperm of a sorghum mutant cultivar, with high in vitro uncooked and cooked protein digestibilities, was examined by transmission electron microscopy and alpha-, beta-, and gamma-kafirins (storage proteins) were localized within its protein bodies. Transmission electron microscopy micrographs revealed that these protein bodies had a unique microstructure related to high protein digestibility. They were irregular in shape and had numerous invaginations, often reaching to the central area of the protein body. Protein bodies from normal cultivars, such as P721N studied here, with much lower uncooked and cooked digestibilities are spherical and contain no invaginations. Immunocytochemistry results showed that the relative location of alpha- and beta-kafirins within the protein bodies of the highly digestible genotype were similar to the normal cultivar, P721N. Gamma-kafirin, however, was concentrated in dark-staining regions at the base of the folds instead of at the protein body periphery, as is typical of normal cultivars. The resulting easy accessibility of digestive enzymes to alpha-kafirin, the major storage protein, in addition to the increased surface area of the protein bodies of the highly digestible cultivar appear to account for its high in vitro protein digestibility. (+info)
Dietary stearic acid reduces cholesterol absorption and increases endogenous cholesterol excretion in hamsters fed cereal-based diets.
(47/1696)
The observation that dietary stearic acid does not raise plasma cholesterol concentration is well documented, although the regulating mechanisms are not completely understood. Therefore, we examined the effect of dietary stearic acid on cholesterol absorption and sterol balance using male Syrian hamsters fed modified NIH-07 cereal-based diets selectively enriched in palmitic acid (16:0), stearic acid (18:0), trans fatty acid (18:1t), cis oleic acid (18:1c) or linoleic acid (18:2). All diets contained 17 g/100 g total fat and 0.05 g/100 g cholesterol; the five fat blends were enriched 30% with the fatty acid of interest above a constant fatty acid background. Cholesterol absorption efficiency was 50-55% in all treatment groups except for the 18:0 group, in which cholesterol absorption was significantly reduced to 21%. Plasma total cholesterol concentration was significantly lower in the 18:0 group compared to the 16:0 group. Fecal neutral steroid excretion was significantly greater in hamsters fed the high 18:0 diet compared to the other treatment groups. After accounting for unabsorbed dietary cholesterol, endogenous cholesterol excretion was about 100% higher in the 18:0 group. Consequently, the calculated rate of whole body cholesterol synthesis was significantly increased by dietary 18:0. Bile acid excretion accounted for only 12-20% of total sterol output by the hamsters in this study. Thus, the data suggest that reduced plasma cholesterol concentration in hamsters fed high 18:0 diets may be influenced by reduced cholesterol absorption and increased excretion of endogenous cholesterol. (+info)
Food induced stimulation of the antisecretory factor can improve symptoms in human inflammatory bowel disease: a study of a concept.
(48/1696)
BACKGROUND: Antisecretory factor (AF), a 41 kDa cloned and sequenced protein, suppresses intestinal inflammation and hypersecretion in animals. Endogenous AF production can be induced by dietary modifications in several animal species, and this feed has been shown to reduce the incidence of diarrhoeal disease in weaning piglets. The role of AF in intestinal disease in humans is not known. AIMS: To study the effects of hydrothermally processed cereals, optimised for AF induction in animals, added to the diet of patients with longstanding symptoms of inflammatory bowel disease (IBD). PATIENTS: Fifty three patients with IBD (ulcerative colitis and Crohn's disease) were entered into the study, and 50 completed follow up. The experimental group consisted of 16 females (mean age 50 (SEM 5) years) and 10 males (41 (4) years) and the placebo group of 12 women (41 (4) years old) and 12 men (51 (5) years). METHODS: Patients were randomised to receive either hydrothermally processed cereals (active treatment) or the same amount of ordinary cereals (placebo treatment) for four weeks in a double blind study design. Baseline diet and medications remained unchanged. Bowel symptoms, plasma levels of AF, and colonic biopsies were evaluated before and after treatment. RESULTS: The active treatment significantly improved subjective ratings of clinical symptoms and increased plasma AF levels compared with placebo. Plasma lipid levels were unaffected. CONCLUSION: Hydrothermally processed cereals can induce AF production in human IBD. This increase in endogenous AF activity is associated with clinical improvement. Further studies are warranted to clarify the exact role of AF in human intestinal disease. (+info)