MRI of transplanted pancreatic islets.

A promising treatment method for type 1 diabetes mellitus is transplantation of pancreatic islets containing beta-cells. The aim of this study was to develop an MR technique to monitor the distribution and fate of transplanted pancreatic islets in an animal model. Twenty-five hundred purified and magnetically labeled islets were transplanted through the portal vein into the liver of experimental rats. The animals were scanned using a MR 4.7-T scanner. The labeled pancreatic islets were clearly visualized in the liver in both diabetic and healthy rats as hypointense areas on T2*-weighted MR images during the entire measurement period. Transmission electron microscopy confirmed the presence of iron-oxide nanoparticles inside the cells of the pancreatic islets. A significant decrease in blood glucose levels in diabetic rats was observed; normal glycemia was reached 1 week after transplantation. This study, therefore, represents a promising step toward possible clinical application in human medicine.     

Latex allergy risk assessment in children and adolescents with type I diabetes mellitus

An increased frequency of allergic reactions to latex has been reported in specific populations with chronic latex exposure. However, relevance of latex allergy to children and adolescents with type I diabetes mellitus (DM1) has not been studied yet. The aim of the studty is to assess latex allergy risk in children and adolescents with DM1. Thirty-nine children with DM1 and 35 controls were enrolled. In a case-control study, we applied to all subjects a standard questionnaire, and specific Immunoglobulin E (IgE) concentrations for latex, common aeroallergens, and food-allergens were measured in serum samples. Latex exposure rates by means of medical procedures, operations, and latex glove usage were not different between DM1 and controls. Symptoms due to latex exposure were not determined in both groups. Three (7.7%) subjects in DM1 tested positive for latex-specific antibodies (LSIE), whereas no subject in controls. Diabetics that tested positive for latex-specific antibodies had the disease for three, 5 and 8 years. Nine (23.1%) of diabetics, and two (5.7%) of controls were atopic (p = 0.04). In our investigation, we found that children and adolescents with DM1 are not a risk group for latex allergy, and LSIE in children with DM1 was not accompanied by symptoms of latex allergy, or, presumably, increased risk of latex anaphylaxis.     

冰点下降法测定血、尿渗透压的临床应用及注意事项

本文应用溶液冰点下降法测定了178例正常血清渗透压。结果为287±13毫渗量/kg水。并对20例尿崩症病人在限水加压素试验过程中测定血清,尿渗透压。尿崩症病人尿渗透压明显低于正常人。注射加压素后,尿渗透压升到正常。在多尿症的鉴别诊断中,此法是一种简便,灵敏的手段。有重要的诊断价值。     

The Changes in the Hypothalamo-Pituitary-Gonadal Axis of Streptozotocin-Treated Male Rats Depend from Age at Diabetes Onset

The influence of age at diabetes onset and of capillary microangiopathy on the severity and evolution of hypothalamo-pituitary-gonadal changes was studied morphologically and morphometrically in male rats 4 and 8 months after streptozotocin injection. At each time period we studied 2 groups of rats, one made diabetic before (age 1 month), the other after puberty (age 3 months), and compared them with corresponding controls. The size of hypothalamic axons, numerical density and size of pituitary gonadotrophs, size of testicular tubules, and basement membrane thickness of retinal capillaries were measured. Major differences were found at 8 months. Changes of pituitary glands (i.e. small and numerous gonadotrophs) and testes (i.e. small tubular size) were more important in pre- than in postpubertal diabetic rats. This was a consequence of the aggravating prepubertal diabetes between 4 and 8 months. On the contrary, these changes partially regressed in postpubertal diabetic animals. Pituitary and testicular changes were correlated. Other lesions, such as swollen axonal processes in the hypothalamus, increased thickness of seminiferous epithelium and of capillary basement membranes, though very evident in diabetics, were independent from age at induction. Neither microangiopathy nor glycemia were correlated with any other change which confirmed their secondary role in diabetic neuroendocrine disorders. Thus, two types of diabetic disorders of the hypothalamo-pituitary-gonadal axis could be distinguished: 1) those with irreversible effects on immature yet partially reversible effects on mature structures; and 2) those independent from age at induction.     

Persistent platelet activation in patients with type 2 diabetes treated with low doses of aspirin

BACKGROUND: The percentage of diabetic patients who do not benefit from the protective effect of aspirin is larger than in other populations at cardiovascular risk. OBJECTIVE: We compared the ability of aspirin to suppress TxA2 and platelet activation in vivo, in type-2 diabetics vs. high-risk non-diabetic patients. METHODS: Urinary 11-dehydro-TXB2, plasma sCD40 L, and sP-selectin were measured, together with indices of low-grade inflammation, glycemic control, and lipid profile, in 82 patients with type-2 diabetes and 39 without diabetes, treated with low doses of aspirin. RESULTS: Urinary 11-dehydro-TxB2, plasma sCD40L and sP-selectin were significantly higher in diabetics than in controls: [38.9 (27.8-63.3) vs. 28.5 (22.5-43.9) ng mmol(-1) of creatinine, P = 0.02], [1.06 (0.42-3.06) vs. 0.35 (0.22-0.95) ng mL(-1); P = 0.0001], [37.0 (16.8-85.6) vs. 20.0 (11.2-35.6) ng mL(-1), P = 0.0001], respectively. The proportion of individuals with diabetes increased across quartiles of 11-dehydro-TxB2, sCD40L, and sP-selectin, with the highest quartiles of 11-dehydro-TxB2, sCD40L and sP-selectin, including 66%, 93.3%, and 93.3% of individuals with diabetes. Markers of platelet activation positively correlated with indices of glycemic control but not with markers of low-grade inflammation. CONCLUSIONS: Platelet dysfunction associated with insufficient glycemic control, may mediate persistent platelet activation under aspirin treatment.     

Diabetes alters μ and κ opioid binding in rat brain regions: comparison with effects of food restriction

Diabetic rats display changes in opioid pharmacology and brain regional levels of opioid peptides and prodynorphin mRNA. Previous investigations of opioid receptor binding, carried out in whole-brain homogenates, have, however, failed to detect changes. In the present study, quantitative autoradiography was used to measure μ and κ opioid receptor binding in discrete brain regions of streptozotocin-treated diabetic rats. Measurement was limited to regions that previously displayed opioid binding changes in chronically food-restricted rats, since our primary aim is to identify brain mechanisms that mediate adaptive responses to persistent metabolic need and adipose depletion. Diabetics displayed strong trends or statistically significant changes which matched seven of the thirteen binding changes observed in food-restricted rats. In no case did diabetics display changes in the opposite direction. The two statistically significant changes common to food-restricted and diabetic rats are increased κ binding in the medial preoptic area and decreased μ binding in the lateral habenula. The possible functional significance of these changes is discussed.     

A Study of Fluoxetine in Obese Elderly Patients with Type 2 Diabetes

In order to establish the safety and efficacy of fluoxetine in subjects over 60 years of age with Type 2 diabetes, a randomized, double-blind, parallel study of 30 obese subjects was undertaken, comparing the use of fluoxetine 60 mg daily with placebo. Subjects were diet controlled with an HbA₁ < 14% (reference range 6–9%) and BMI > 29 kg m². Those taking fluoxetine had a median weight loss of 2.6 kg at 3 months (p < 0.001) and 3.9 kg at 6 months (p < 0–02), compared with weight loss in the placebo group of 0.1 kg and 0.0 kg at 3 and 6 months, respectively. Improved glycaemic control was also demonstrated in the fluoxetine group compared with placebo, initial HbA₁ levels of 8.0% vs 8.7% (NS) falling at 4 months by 0.9% (p < 0.02) and at six months by 0.9% (p < 0.02). No sustained improvement in fasting blood glucose levels was demonstrated. Reporting of adverse events was similar in both groups. Fluoxetine in the short term aids weight loss and improves glycaemic control without a significant increase in adverse events in elderly Type 2 diabetic subjects.