Some nutritional properties of unrefined sugar and its promotion of the survival of new-born rats.

1. The claims that rats fed on diets with ‘brown sugar’ (unrefined muscovado) perform better in a number of ways than do rats fed on refined white sugar (sucrose) have been examined. 2. Male Wistar rats were fed on purified diets from weaning, in which the carbohydrate component was either maize starch or unrefined sugar or sucrose. The sugars produced no differences in growth rate, body composition, or the weights of liver or kidneys. Compared with sucrose, unrefined sugar produced an increase in blood cholesterol and in the activity of hepatic fatty acid synthetase, and a greater increase in blood triglyceride. In confirmation of earlier results, rats fed on either sugar had heavier livers and kidneys, increased activity of hepatic glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and a higher concentration of plasma triglyceride compared with rats fed on maize starch. 3. Female Sprague-Dawley rats were fed on the same three diets as the male rats, and mated when they weighed about 200 g. No difference was seen in their ability to mate, the progress of pregnancies, or the sizes of the litters. Does fed on unrefined sugar produced litters of higher viability than did does fed on starch or sucrose. Survival was between 85 and 100% with unrefined sugar and between 30 and 75% with starch or sucrose. 4. Unrefined muscovado sugar has thus been shown to contain a factor required by female rats for the proper viability of their pups. This may be the same ‘Reproductive Factor R’ as that described by Wiesner & Yudkin (1951). In certain circumstances, unrefined muscovado sugar might therefore contribute to the nutritional value of a human diet, although in what circumstances, in what respect and to what extent it might do so, is by no means clear

The influence of dietary carbohydrate and fat on kidney calcification and the urinary excretion of N-acetyl-beta-glucosaminidase (EC 3.2.1.30).

1. Male Sprague-Dawley rats were fed on diets containing either sucrose or starch as the carbohydrate component. In one experiment, the diets also contained 200 g either butter or polyunsaturated margarine/kg; in a second experiment, the diets contained less fat in the form of 20 g maize oil/kg. 2. Over a period of 11 months assays were made in the urine of several ions and of the activity of the enzyme N-acetyl-β-glucosaminidase (β-2-acetamido-2-deoxy-β-D glucoside acetamidodeoxygluco-hydrolase; EC 3.2.1.30); at 13 months, examination was made of some of the abdominal viscera, especially of the kidneys. 3. In rats fed on the higher amount of fat, dietary sucrose produced a higher activity of the enzyme than did dietary starch, and a greater excretion of inorganic phosphate. 4. With both the higher and lower amounts of dietary fat, sucrose led to an increase in the weight of the liver and of the kidneys, and an increase in the concentration of calcium and of phosphate in kidney tissue. With the higher amount of fat, sucrose also produced an increase in the concentration of magnesium in the kidney. There was no difference in the concentration of any of the ions assayed in the plasma or, apart from inorganic phosphate, in the urine. 5. The kidneys of the sucrose-fed rats showed nephrocalcinosis, mostly in the cortico-medullary region, and basophilic deposits in the tubules. Attention is drawn to this unusual occurrence of nephrocalcinosis in male rats

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Contains reports on four research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-03)National Aeronautics and Space Administration (Grant NsG-496)Lincoln Laboratory (Purchase Order DDL BB-107)United States Air Force (Contract AF19(628)-500

Rethinking the appraisal and approval of drugs for type 2 diabetes

The process for approving new drugs for type 2 diabetes illustrates the significant shortcomings of the regulatory standards for licensing, reimbursing, and adopting new drugs. Regulatory reform is needed to improve the real-world therapeutic value of anti-diabetic drugs

Sample size calculations for cluster randomised controlled trials with a fixed number of clusters

Background\ud Cluster randomised controlled trials (CRCTs) are frequently used in health service evaluation. Assuming an average cluster size, required sample sizes are readily computed for both binary and continuous outcomes, by estimating a design effect or inflation factor. However, where the number of clusters are fixed in advance, but where it is possible to increase the number of individuals within each cluster, as is frequently the case in health service evaluation, sample size formulae have been less well studied. \ud \ud Methods\ud We systematically outline sample size formulae (including required number of randomisation units, detectable difference and power) for CRCTs with a fixed number of clusters, to provide a concise summary for both binary and continuous outcomes. Extensions to the case of unequal cluster sizes are provided. \ud \ud Results\ud For trials with a fixed number of equal sized clusters (k), the trial will be feasible provided the number of clusters is greater than the product of the number of individuals required under individual randomisation ($n_i$) and the estimated intra-cluster correlation ($\rho$). So, a simple rule is that the number of clusters ($\kappa$) will be sufficient provided: \ud \ud $\kappa$ > $n_i$ x $\rho$\ud \ud Where this is not the case, investigators can determine the maximum available power to detect the pre-specified difference, or the minimum detectable difference under the pre-specified value for power. \ud \ud Conclusions\ud Designing a CRCT with a fixed number of clusters might mean that the study will not be feasible, leading to the notion of a minimum detectable difference (or a maximum achievable power), irrespective of how many individuals are included within each cluster. \ud \u

Relation of C-reactive protein to body fat distribution and features of the metabolic syndrome in Europeans and South Asians.

OBJECTIVE: To investigate the association between circulating C-reactive protein (CRP) concentrations and indices of body fat distribution and the insulin resistance syndrome in South Asians and Europeans. DESIGN: : Cross-sectional study. SUBJECTS: A total of 113 healthy South Asian and European men and women in West London (age 40-55 y, body mass index (BMI) 17-34 kg/m(2)). MEASUREMENTS: Fatness and fat distribution parameters (by anthropometry, dual-energy X-ray absorptiometry and abdominal CT scan); oral glucose tolerance test with insulin response; modified fat tolerance test; and CRP concentration by sensitive ELISA. RESULTS: Median CRP level in South Asian women was nearly double that in European women (1.35 vs 0.70 mg/1, P=0.05). Measures of obesity and CRP concentration were significantly associated in both ethnic groups. The correlation to CRP was especially strong among South Asians (P0.15). CONCLUSION: We suggest that adiposity and in particular visceral adipose tissue is a key promoter of low-grade chronic inflammation. This observation may in part account for the association of CRP with markers of the metabolic syndrome. Future studies should confirm whether CRP concentrations are elevated in South Asians and whether losing weight by exercise or diet, or reduction in visceral fat mass, is associated with reduction in plasma CRP concentrations