Objective　To investigate if there is any effect of interleukin-18 (IL-18) or if IL-18 modulates IL-1β effects on islet fun ction.Methods　Insulin release and nitrite production from isolated islets of newborn Wistar rats were measured after incubation with or w ithout cytokines.Reverse transcription polymerase chain reaction (RT-PCR) was u sed to detect mRNA expression of the IL-18 receptor signaling chain (IL-18Rβ) .Results　(1) There were no significant effects of 0.625～ 10nmol/L of recombinant murine (rm) IL-18 alone on accumulated or glucose-cha llenged insulin release and nitrite production after 24h.(2) 15pg/ml of recombi nant human (rh) IL-1β significantly increased nitrite production and inhibited insulin release.However,0.625～10nmol/L of rm IL-18 failed to modulate the abo ve effects caused by IL-1β.(3) 24h rm IL-12 preincubation failed to sensitize islets to the effects of 10nmol/L of rm or recombinant rat (rr) IL-18 alone or to pri me islets to IL-1β actions on insulin release and nitrite production.(4) IL-1 8Rβ mRNA was not expressed in isolated islets even after exposure to IL-12 for 48h.Conclusion　Unlike IL-1β,IL-18 dose not play a dir ect role in the destruction of islet β-cell function.

Objective　To explore the mechanism of effects o f endotoxin (LPS) on apoptosis of pancreatic islet cells in rat.Metho ds　After the model of endotoxemia was established in rat with intrap eritoneal injection of LPS (2mg/kg),the changes of nitric oxide (NO) level in se rum and pancreas were dynamically determined.The expression of inducible nitric oxide synthase (iNOS) was also observed by situ hybridization in the islet,Moreo ver,DNA damage in islet cells by the external donor of NO (sodium nitroprussid e) and LPS in vitro with single cell gel electrophoresis and agarose gel electro phresis of DNA were also evaluated.Results　NO level in se rum was significantly increased at the 6th,and persisted to the 3rd day after in jection of LPS,the NO in pancreas was also elevated,but recovered to the normal at 24h. The expression of iNOS in pancreatic islet also began to enhance at the 6th and significantly enhanced at the 12th after endotoxemia.In vitro experiment sho wed that exogenous NO markedly caused the damage of DNA in islet cells,but LPS d i d not exert the same effects.Conclusion　The mechanism of the effcts of endotoxin on apoptosis of islet cells might stimulate the expressi on of iNOS in inflammatory or non-inflammatory cells that generates the NO indu cing the DNA damage of islet cells.

Objective　To explore the association between th e heparan sulfate proteoglycan gene (HSPG) polymorphism and diabetic nephropathy in Chinese.Methods　A case control study of 326 Chinese s ubjects including 136 type 2 diabetics with or without nephropathy and 190 non- diabetic control was performed.Genotype frequencies of HSPG2 polymorphism were s tudied by PCR-RFLP analysis with BamHI digestion.Results　There was no difference in genotype frequencies or allele frequencies between normal albuminuria and abnormal albuminuria patients.Moreover,there was no assoc iation between diabetic patients and non-diabetic control in allele frequencies as well,but obvious difference in genotype frequencies(0.05＞P＞0.025) was found.Conclusion　Our study showed the lack of association between HSPG polymorphism and diabetic nephropathy in Chinese type 2 diabetics. There may be association between genotype frequencies of HSPG polymorphism and d iabetes in statistics.

Objective　To investigate the influence of pretr eatment with anti-B lymphocyte serum on the immunogenecity and endocrine functi on of islet preparations.Methods　Porcine ICCs were pretre ated with anti-B lymphocyte serum which was produced using the mixed adult porc i ne B lymphocyte as antigen.The immunogenecity of islet was measured by mixed isl et lymphocyte culture (MILC) and SLA-DR positive cell number within the islet and the islet function was assayed with insulin release test.Results 　The cpm value of MILC of the group pretreated with anti-B lymphocy te serum and the MHCⅠ antigen and SLA-DR antigen positive cell numbers was mar kedly decreased in comparison with that of control group (P＜0.001).There wa s no significant difference in insulin release of additional different groups.[ WT5”HZ Conclusion　The pretreatment of islet preparation with anti -B lymphocyte serum may decrease the immunogenecity of islet preparation,while there is no marked influence on its insulin release function.

Objective　A recent study has shown the association between a sulfonylurea receptor gene-1 (SUR1) variant and hyperinsulinemia in normal individuals from a high diabetes risk ethnic group,supporting the hypothesis that the primary insulin hypersecretion may be an antecedent of type 2 diabetes.Methods　To test this hypothesis in Chinese population,we studied the allele and genotype distribution of the polymorphism at -3 position of intron 24 in SUR1 by PCR-RFLP technique in 206 unrelated normal glucose tolerant subjects with strong family history of type 2 diabetes (group A) and 110 normal individuals without family history of diabetes (group B).Results　The frequency of “-3c” allele and “-3cc” genotype of intron 24 in group A was significantly higher than that in group B (64% vs 54%，P=0.004 and 38% vs 24%，P=0.002 respectively).Moreover,in group A, those carrying “cc” genetype had a higher BMI (27.27±6.37 vs 24.99±3.43kg/m2，P＜0.05；27.27±6.37 vs 25.28±2.78kg/m2，P＜0.05),fasting insulin (15.52±10.72 vs 9.27±5.03U/ml,P＜0.01；15.52±10.72 vs 10.79±7.80U/ml,P＜0.05) and 2h insulin levels (76.41±54.02 vs 55.43±49.60U/ml,P＜0.01；76.41±54.02 vs 55.71±40.39, P＜0.05) as well as lower insulin sensitivity ［HOMA(Ri］: 4.00±3.09 vs 2.79±1.32, P＜0.01； 4.00±3.09 vs 2.82±2.94, P＜0.01) as compared with that in carriers of other genotypes (“ct” and “tt”).Conclusion　This study suggested the possibility that the defect in SUR1 gene might contribute to the insulin hypersecretion which might be the cause of subsequent increased body weight and decreased insulin sensitivity.

Objective　To study the predictive value of islet cell antibody (ICA),64KD protein antibody(64KDAb) and insulin auto-antibody (IAA) in the first-degree relatives of type 1 diabetics.Methods　The determination of islet autoantibody distribution in type 1 diabetes patients,first-degree relatives without diabetes and normal individuals was made.Results　The results revealed that ICA and 64KDAb positive rate in type I diabetes patients and their first-degree relatives was significantly higher than normal individuals.The positive rate of 64KDAb is higher than that of ICA and IAA. Conclusion　These results suggest that 64KDAb's sensitivity is higher than ICA and IAA's,so 64KDAb is more valuable as the marker of predicting type 1 diabetes.The combined determination of ICA,64KDAb and IAA might improve the value for predicting diabetes.

Objective　To study the changes of the four active substances endothelin(ET),calcitonin gene related peptide (CGRP),thromboxane B2(TXB2) and 6-Keto-prostaglandin F1α(6-Keto-PGF1α) in plasma when they acted on each other in the formation and development of diabetic retinopathy.Methods　Using the method of radio-immunity,the levels of ET,CGRP,TXB2,6-Keto-PGF1α in plasma were measured in four groups of patients with type 2 diabetes (group 1∶40 cases without retinopathy;group 2∶40 cases with primary retinopathy;group 3.40 cases with hyperplasia type of retinopath;group 4∶40 cases normal controls).Results　The results showed that ET increased progressively (P＜0.01) with the prolonging of the duration of DM and the worsening of retina damage、CGRP showed a decreasing tendency (P＜0.05,P＜0.01) in the advanced stage of DM retinopathy.Rectilinear regression analysis showed that the association of ET/CGRP with TXB2/6-Keto-PGF1α became closer with the worsening of deabetic retinopathy (r=0.44,P＜0.05;r=0.596,P＜0.01).Conclusion　The four active substances acted on each other in the formation and development of diabetic retinopathy.It had a significent meaning in the initial mechanism of DM,in the development of disease and in the direction of medication usage to understand their relationship.

Objective To investigate the effect of HIV-1 protease inhibitor saquinavir on insulin signaling and β-cell function in rat INS-1 cells. Methods INS-1 cells were preincubated with 0 or 10 μmol/L saquinavir for 48 h, stimulated with 100 nmol/L insulin for 2 min or 20 mmol/L glucose for 30 min. Insulin signaling parameters were analyzed by immunoprecipitation and Western blot on cell lysates. Insulin concentrations in the supernatant were measured by ELISA, and standardized by cellular DNA contents. Cell count with trypan blue stain and MTT test were determined to evaluate the effect of saquinavir on cell viability. Results Treatment with saquinavir for 48 h significantly decreased insulin-stimulated phosphorylation of IRS-1, IRS-2 and Thr~(308)-phosphorylation of Akt in INS-1 cells by 60%, 66% and 55%, decreased the rate of basal insulin secretion and glucose-stimulated insulin release by 39% and 49% compared with control cells, respectively. Conclusions Treatment with saquinavir impairs insulin signal transmission in pancreatic β cells and results in insulin resistance in β cells. This effect might influence the function of β cells.

Objective To investigate the effects of mTOR/S6K1 signaling pathway on the development of insulin resistantce. Methods 20 male C57BL/6 mice were divided into normal diet group (NC) and high fat diet group (HF).HF mice were fed with high fat diet for 14 weeks and insulin resistance was confirmed in all mice. We observed the morphology of pancreatic islet by HE staining. Serum insulin concentration was also evaluated by ELISA. Northern blot, Western blot and immunofluorescence were performed to detect mTOR and S6K1 mRNA and protein expression in skeletal muscle. Results As compared with NC group,HF group showed that the body weight and fasting serum insulin level were increased by 21.99%(P＜0.05) and 181.82%(P＜0.01) respectively;the area of pancreatic islet was significantly increased;glucose tolerance was impaired;expressions of mTOR mRNA (125.61±10.43 vs 100.00, P＜0.05) and protein (137.41±7.86 vs 100.00, P＜0.01) were significantly increased. And we also found an significant increase in total S6K1 mRNA (154.98±16.26 vs 100.00, P＜0.01) and protein (137.36±3.08 vs 100.00,P＜0.01) as well as pS6K1 protein (390.15±69.62 vs 50.59±16.65,P＜0.01)expression in HF group as compared with NC group.Conclusions mTOR/S6K1 signaling pathway plays an important role in the development of higt fat diet induced insulin resistance.

Objective To determine the causative organisms and antimicrobial susceptibility of community- and hospital-acquired pneumonia (CAP and HAP) in type 2 diabetes in Fujian Provincial Hospital. Methods The data of becteria spectrum and their drug susceptibility in patients with type 2 diabetes complicated by pulmonary infection were retrospectively analyzed in January 1995 to October 2006. Results The isolated bacteria of sputum culture of 494 cases included 73 gram-positive cocci(16.7%),139 gram negative bacilli(31.9%)and 224 fungus(51.4%).G+ cocci mainly included staphylococci,G-bacilli mainly included Klebsiella pneumoniae,Bowman immovability bacillus and Pseudomonas aeruginosa.In both CAP and HAP,fungus and G- bacilli were the dominant pathogens.The pathogenic bacteria were resistant to multi-antibiotics,and the resistant rates from HAP patients was higher than those from CAP. Of the bacterial strains isolated from blood culture,G-bacilli constituted 87.5%. Conclusions Fungus and G-bacilli were the dominant pathogens.Phlegm culture and drug sensitive test are helpful for reasonable use of antibiotics for patients with type 2 diabetes complicated by pulmonary infection in clinical practice.