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.     

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.     

Evaluation of the percentage of sperm motility at 24 h and sperm survival ratio for prediction of in vitro fertilization

Summary. The present study was carried out to investigate the predictive value of the percentage of sperm motility after 24-h incubation and sperm survival ratio from semen and inseminated sperm suspension using grading of motility by WHO criteria with respect to the fertilization of oocytes in vitro. A total of 789 oocytes from 85 cases were inseminated and the mean fertilization rate obtained was 72.5%. There was no significant correlation between all of the sperm motility results with fertilization rate in vitro. All sperm motility results were not significantly different between the non-fertilizing group and the fertilizing group and also between the group of fertilization rate ≤ 25th percentile (fertilization rate ≤62.5%) and the group of fertilization rate >62.5%. However, the initial percentage of rapid progressive sperm motility and progressive motility in semen and inseminated sperm suspension at 24 h gave significant differences between the group of fertilization ≤ 50th percentile (fertilization rate ≤80%) and the group of fertilization rate >80%. Overall accuracy using these parameters for prediction of fertilization rate >80% was only about 60%. In conclusion, the percentage of sperm motility at 24 h and sperm survival ratio in both semen and inseminated sperm suspension have no practical value in predicting fertilization rate in vitro. Moreover, detailed motility grading cannot improve the predictivity of these sperm motility parameters.     

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.     

Correlation between in vivo and in vitro toxic effects of foreign compounds

Studies in rats in vivo and in isolated hepatocytes from the same species and strain of animal in vitro with the hepatotoxicant hydrazine have shown that despite measuring the same parameters in each system, the effects do not always show a quantitative or qualitative correlation. For example depletion of glutathione and ATP occurred in both systems but required a much higher concentration of hydrazine in vitro. The effects on triglyceride levels, citrulline synthesis and taurine levels in vivo were not observed in vitro and the inhibition of urea synthesis and cytotoxicity in vitro were not observed in vivo.Inhibition of protein synthesis proved to be the marker which showed the best correlation, occurring at a similar hydrazine concentration in vitro and in vivo although not to the same extent.The situation with other toxicants is variable, in some cases correlation is good, in others modification of conditions in vitro are required.     

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.     

The use of a priori knowledge to quantify short echo in vivo 1h mr spectra

In vivo ¹H MR spectra of the prefrontal cortex acquired with the stimulated echo acquisition mode (STEAM) TE = 20 ms sequence were quantified to determine relative levels of cerebral metabolites. A priori knowledge of spectra from individual metabolites in aqueous solution was incorporated into a frequency domain quantification technique. The accuracy and precision of modeling these metabolites were investigated with simulated spectra of varying signal-to-noise ratios (SNRs) and relative metabolite levels. The efficacy of modeling in vivo data was tested by quantifying 10 repeated measures of two consecutively acquired in vivo spectra (an 8?cm³ volume of interest (VOI) and a 4?cm³ VOI positioned within the 8?cm³ VOI) on the same normal subject. The differences in levels of glutamate (Glu), phosphocreatine plus creatine (PCr+Cr) and choline-containing compounds (Cho₁ between spectra from the 8? and 4?cm³ VOIs corresponded with the expected differences observed in the proportions of gray matter within the VOIs (estimated from ¹H images). Correcting for the T₁ and T₂ relaxation, the estimated concentrations of N-acetylaspartate, PCr+Cr, Cho₁, Glu, and glutamine were consistent with previous in vivo and in vitro reports.     

正常孕妇孕期中血清铁蛋白,叶酸,VitB12的动态观察

对首钢职工中２９０例正常初产在妊娠早，中，晚三期进行血清铁蛋白（ＳＦ），血清叶酸（ＦＡ），ＶｉｔＢ１２，Ｈｂ和ＲＢＣ五项指标追踪观察，结果：孕妇妊娠期ＳＦ，ＦＡ，Ｈｂ，ＲＢＣ均随孕期的增加而下降，而ＶｉｔＢ１２变化较小，并缺少上述规律性。