Coronary by-pass operations in diabetic and non-diabetic patients with angina. Results of 102 coronary arteriographies (author's transl)]

The results of coronary arteriography were compared in 102 patients (55 non-diabetics and 47 diabetics) with angina. The lesions noted an arteriography were more severe in the diabetic patients: more frequent stenosis in the common trunk and three branches, and present in greater numbers (more than 4 in more than a half of the patients), with only a moderate proximal bed in 65% of the cases. By-pass operations can only be performed, therefore, in 32% of these patients as against 54% for the non-diabetic anginal patients. The operative risk also appears to be increased (1 death and 6 complications in 10 by-pass operations). It was also demonstrated that with similar lesions of the common trunk, the diabetics have radiological signs of a greater incidence of cardiomegaly and generalized hypokinesia of the left ventricle than non-diabetics. By-pass operations are impossible in about 85% of patients because of ischemic signs or evidence of necrosis in the ECG recordings of diabetic patients with angina.     

Comparison of retinal vessel measurements in digital vs film images

PURPOSE: To compare central retinal artery equivalents (CRAE) and central retinal vein equivalents (CRVE) from vessels measured from images captured with a digital camera and digitized images taken with a film camera. DESIGN: Comparison of techniques. METHODS: SETTING: Clinic. Patients: A total of 75 eyes of 48 adults. OBSERVATION PROCEDURES: Gradings of retinal vessel diameters from images produced by using two photographic techniques: directly from a 45 degrees digital camera and digitized by scanning from a 30 degrees film-based camera. MAIN OUTCOME MEASURE: Differences in CRAE and CRVE from two types of images. RESULTS: CRAE and CRVE were highly comparable between the two techniques with correlation coefficients of 0.88 and 0.87, respectively. CONCLUSION: Estimates of CRAE and CRVE from measurements taken from digitally captured and digitized film-based images were highly comparable. It is likely that inferences about factors associated with retinal vessel diameters will be unbiased by the method of imaging.     

Intrinsic gluconeogenesis is enhanced in renal proximal tubules of Zucker diabetic fatty rats

Recent studies indicate that renal gluconeogenesis is substantially stimulated in patients with type 2 diabetes, but the mechanism that is responsible for such stimulation remains unknown. Therefore, this study tested the hypothesis that renal gluconeogenesis is intrinsically elevated in the Zucker diabetic fatty rat, which is considered to be an excellent model of type 2 diabetes. For this, isolated renal proximal tubules from diabetic rats and from their lean nondiabetic littermates were incubated in the presence of physiologic gluconeogenic precursors. Although there was no increase in substrate removal and despite a reduced cellular ATP level, a marked stimulation of gluconeogenesis was observed in diabetic relative to nondiabetic rats, with near-physiologic concentrations of lactate (38%), glutamine (51%) and glycerol (66%). This stimulation was caused by a change in the fate of the substrate carbon skeletons resulting from an increase in the activities and mRNA levels of the key gluconeogenic enzymes that are common to lactate, glutamine, and glycerol metabolism, i.e., mainly of phosphoenolpyruvate carboxykinase and, to a lesser extent, of glucose-6-phosphatase and fructose-1,6-bisphosphatase. Experimental evidence suggests that glucocorticoids and cAMP were two factors that were responsible for the long-term stimulation of renal gluconeogenesis observed in the diabetic rats. These data provide the first demonstration in an animal model that renal gluconeogenesis is upregulated by a long-term mechanism during type 2 diabetes. Together with the increased renal mass (38%) observed, they lend support to the view so far based only on in vivo studies performed in humans that renal gluconeogenesis may be stimulated by and crucially contribute to the hyperglycemia of type 2 diabetes.