Determination of vhl gene mutations in sporadic renal cell carcinoma

OBJECTIVE: Characterization of the molecular status of the vhl gene and its relationship to the usual prognostic factors could help establish new diagnostic and therapeutic strategies. This study determines the presence of vhl gene mutations in tumor tissue from patients with sporadic renal cell carcinoma, the relationship between the mutations and classic prognostic factors, and the possible impact on protein function. MATERIALS AND METHOD: Cross-sectional analytical study investigating vhl gene mutations in tumor tissue by PCR testing of the gene exons and automatic sequencing in 96 patients with sporadic renal cell carcinoma. The characteristics of the mutations detected, as well as their relationship with various clinical and pathological parameters and the possible impact on protein function, were analyzed. RESULTS: Twenty-two mutations were found in 21 patients (21.9%); 68.2% were point mutations. The mutations were associated only with tumor histotype and were located in protein functional domains. Three mutations were detected in the intron position; 73.7% were considered relevant to protein function. CONCLUSION: The percentage of vhl gene mutations in sporadic renal cell carcinoma was relatively low, mutations were seen more often in clear cell carcinoma and were not related to the classic clinical prognostic factors. Mutations of the vhl gene produce important changes in the protein, causing it to lose its tumor suppressor function.     

Glucagon,insulin, and glucose responses to physiologic testing in normal and massively obese adults

Ten normal adults and ten nondiabetic massively obese subjects were studied following 4–7 days on identical diets. Intravenous arginine challenge resulted in similar glucose and glucagon responses and threefold greater integrated insulin responses in the obese when compared to the normal subjects. Following oral glucose, glucagon responses were similar, whereas both basal and integrated insulin values were higher in the obese subjects. Basal and integrated insulin concentrations were greater during intravenous glucose testing in the obese subjects, whereas similar glucagon suppression was observed in both groups. Hourly blood samples obtained during a 24-hr period revealed that the obese glucose profile differed significantly from the normals. Insulin values were two- to four-fold higher in the obese subjects, whereas no significant difference was observed in the glucagon concentrations. The nadir and peak glucagon concentrations for both groups occurred at 8:00 a.m. and 8:00 p.m., respectively, and were positively correlated with plasma amino acid values, and were similar in both groups.     

Oesophageal manometric studies in patients with chronic Chagas disease and megacolon

Intraluminal manometric studies performed on 12 patients with chronic Chagas disease and megacolon without clinical or radiological abnormalities of the oesophagus showed no alteration in oesophageal physiology under basal conditions when compared with a control group of 30 healthy subjects. Oesophageal peristalsis was unimpaired.Patients with chronic Chagas disease and megacolon differed from normals in their reaction to a small dose of a cholinergic drug. This agent induced an isolated but significant increase in resting pressure at the level of the oesophagogastric sphincter, accompanied in most cases by an increase in spontaneous activity but not by a change in resting pressure in the body of the oesophagus. This is interpreted as a subclinical expression of oesophageal pathology related to Chagas disease.