X-ray crystal structure of the ferric sperm whale myoglobin: imidazole complex at 2.0 A resolution.

The X-ray crystal structure of the ferric sperm whale (Physeter catodon) myoglobin:imidazole complex has been refined at 2.0 A resolution, to a final R-factor of 14.8%. The overall conformation of the protein is little affected by binding of the ligand. Imidazole is co-ordinated to the heme iron at the distal site, and forces distinguishable local changes in the surrounding protein residues. His64(E7) swings out of the distal pocket and becomes substantially exposed to the solvent: nevertheless, it stabilizes the exogenous ligand by hydrogen bonding. The side-chains of residues Arg45(CD3) and Asp60(E3) are also affected by imidazole association.

gamma-Glutamyl-transpeptidase in diabetics: a case control study.

Several investigators have reported high levels of gamma-glutamyl-transpeptidase (GGT) in the diabetic population. Therefore, we undertook a study to see the prevalence of 'isolated' high GGT in a large population of diabetics without chronic liver disease (CLD), as compared to an age- and sex-matched control group of non-diabetic subjects without CLD, and the role of extrahepatic factors in 'isolated' high GGT, as possible etiopathogenetic causes. We selected 351 diabetics with normal hepatologic screening, without echographic abnormalities of the hepatic parenchyma or the biliary tract. Age, duration and therapy of diabetes, body mass index (BMI), alcohol consumption, glycosylated hemoglobin (HbA1), and the presence of hepatitis B virus (HBV) were studied to see if they are related to high GGT. The control group included 260 age- and sex-matched non-diabetic subjects. We did not find any significant difference between diabetics and the control group in the prevalence of high GGT (mean: 17.5% vs. 23%; women: 16% vs. 14.5%). Multiple regression analysis showed that alcohol consumption plays the major role in the high GGT of both men and women.

Role of hepatitis B virus infection in chronic liver disease of diabetic patients: a case-control study.

In the literature there is no agreement on the prevalence of chronic liver disease (CLD) and the role of hepatitis B virus (HBV) infection in diabetics. We undertook an epidemiological case-control study of the prevalence of CLD and HBV infection in 394 diabetics and 265 healthy subjects from Seriate and Como. The results did not show any significant differences between: 1) the prevalence of CLD in the diabetic population and in controls (4.8% vs 4.5%); 2) the prevalence of HBV infection in diabetics (HBsAg+: 8.3%; HBVAb+: 55.8%) and in controls (HBsAg+: 8.6%; HBVAb+: 54.7%); 3) the prevalence of HBV infection in diabetics with CLD (HBsAg+: 21%; HBVAb+: 52.6%) and in controls with CLD (HBsAg+: 16.6%; HBVAb+: 50%); 4) the prevalence of HBV infection in diabetics with and without CLD (HBsAg+: 21% vs 7.7%; HBVAb+: 52.6% vs 56%); 5) the prevalence of HBV infection in diabetics treated by injection and orally (HBsAg+: 6.9% vs 8.6%; HBVAb+: 58.3% vs 55.2%). The relative risk of CLD for the factor HBsAg+ was 3.2 in the diabetic population vs 1.4 in controls. In view of the presence of antidelta antibodies (HDVAb) in 25% of HBsAg+ diabetics with CLD and the lack of HBV markers in 26.3% of diabetics with CLD, we assume that other viruses (Delta, nonA-nonB) may play roles. Probably the interaction of all possible etiopathogenetic factors (alcohol, viruses, glycometabolic derangement) is determinant for CLD in diabetics.

Decrease of intestinal tumors induced by 1,2-dimethylhydrazine in rats fed with cow milk and buffalo milk

Epidemiological studies in human beings and experimental studies in laboratory animals suggest that milk and dairy products can inhibit effects on the development of some kinds of tumors. Cow milk contains sphingomyelin, butyric acid, conjugated linoleic acid, calcium, vitamin A, carotene and vitamin D. All of these components are known to inhibit the process of carcinogenesis. Our objective was to determine the effect of cow milk and water buffalo milk on the development of colon neoplasias in an experimental model of carcinogenesis in rats induced with 1,2-dimethylhydrazine (DMH). Three-month-old Wistar male rats with an average body weight of 180 g were given a nutritionally adequate diet and drinking water adlivitum, cow milk or water buffalo milk. The milk diets were provided two weeks before the first DMH treatment and their administration was continued during the 10 weeks of DMH treatment. Milk administration finished two weeks after the last DMH doses treatment. Four months after the last carcinogen injection, all surviving animals were sacrificed and examined for intestinal tumors. The number, size, and location of the tumors were recorded and gross pathology was described. Small tumors (< 2.5 mm) were examined by Scanning Electron Microscopy (SEM). Significantly fewer tumors were observed in both groups treated with DMH and supplemented with milk, than in the group treated with DMH without milk administration.