Relations between serum adipocyte fatty acid-binding protein and type 2 diabetes in a community population / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between the serum levels of adipocyte fatty acid-binding protein (A-FABP) level and type 2 diabetes mellitus in a community population.</p><p><b>METHODS</b>A total of 255 residents (aged 45-85 years) were randomly selected from 4 communities in Guangzhou to examine the fasting plasma glucose (FPG), 2-hour postprandial blood glucose (2hPG), glycosylated hemoglobin (HbA1c), body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), blood pressure (BP), triglyceride (TG), cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). The insulin resistance index (HOMA-IR) was calculated and enzyme-linked immunosorbent assay (ELISA) was used to determine serum A-FABP and fasting insulin (FINs) levels. The cases were divided into 3 groups according to blood glucose level, namely the normal group (group A, n=90), impaired glucose tolerance group (group B, n=85), and diabetic group (group C, n=80), and the A-FABP levels were compared between them.</p><p><b>RESULTS</b>Compared with group A, the subjects in groups B and C showed significantly increased FPG, 2hPGh, HbA1C, HOMA-IR, systolic blood pressure (SBP), and waist circumference (P=0.000) as well as FINs, WHR, diastolic blood pressure (DBP) , TG, and HDL-C (P=0.038, 0.047, 0.01, and 0.046, respectively). Compared with group B, group C showed significantly higher FPG, 2hPG, HbA1c, TG, and SBP (P=0.00), with also higher levels of FINs, BMI, WC, DBP, and HDL-C (P=0.012, 0.006, 0.03, 0.019, and 0.029, respectively). A-FABP increased significantly in the order of group A, B, and C (P=0.00), and this result was not affected by the differences in age between the 3 groups (P>0.05). A-FABP level was positively correlated to FPB, 2hPG, FINS, WHR, BMI, WC, SBP, and HOMA-IR, but inversely to TG and HDL-C (P=0.00).</p><p><b>CONCLUSION</b>Elevated serum A-FABP is closely related to glucose metabolism disorder, and A-FABP may serve as a useful marker for the occurrence and development of type 2 diabetes in the community population.</p>

Clinical significance of glycosylated serum protein in patients with diabetic nephropathy / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the relations between fasting blood glucose (FBG), glycosylated hemoglobin A1c (HbA1c) and glycosylated serum protein (GSP).</p><p><b>METHODS</b>FBG, HbA1c and GSP were measured in 303 patients with diabetic nephropathy and in 167 non-diabetic patients with comparable baseline data, and the correlations between FBG, HbA1c and GSP were analyzed.</p><p><b>RESULTS</b>GSP levels were significantly higher in patients with diabetic nephropathy than in the non-diabetic patients (P<0.01). In patients with diabetic nephropathy, GSP levels were found to positively correlate to FBG (r=0.606) and HbA1c (r=0.733).</p><p><b>CONCLUSION</b>Patients with diabetic nephropathy show strong correlations between FBG, HbA1c and GSP. GSP detection is convenient, stable, and practical in evaluating the average FBG over a short term, which reduces the interference by FBG fluctuations in conventional blood glucose monitoring.</p>

Analysis of glucose levels and the risk for coronary heart disease in elderly patients in Guangzhou Haizhu district / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the prevalence of diabetes and prediabetes and their association with the risk for coronary heart disease (CHD) in elderly residents in Haizhu District of Guangzhou.</p><p><b>METHODS</b>Stratified random sampling was employed to select a total of 1800 resident aged 50 years or older in the region. The fasting fingertip blood glucose>5.6 mmol/L was used as the criterion for the initial screening. The data were collected from qualified subjects via scheduled questionnaire surveys, blood collection and testing, and physical examination. The subjects were divided into the 3 groups, namely normal blood glucose, prediabetes, and diabetes groups. The combination rates of the relevant risk factors (hypertension, hyperlipemia, obesity, and central obesity) were compared among the groups by Framingham Heart Study to predict the occurrence of CHD in 10 years.</p><p><b>RESULTS</b>The incidence was 11.00% for prediabetes and 7.56% for diabetes in the elderly residents in Haizhu District. The occurrence of hypertension, hyperlipemia, obesity, and central obesity was significant higher in the prediabetes and diabetes group than in the normal blood glucose group, and showed no significant differences between the former two groups. The 10-year risks for CHD were markedly higher in both the prediabetes and diabetes groups than in the normal blood glucose group, but similar between the former two groups.</p><p><b>CONCLUSION</b>Elderly patients with prediabetes and diabetes have significantly increased 10-year risk for CHD in comparison with those with normal blood glucose, but the risk is similar between the former two groups, indicating a close association of IGR (impaired fasting glucose+ impaired fasting glucose) with CHD. Early control of blood glucose is essential to the prevention and control of CHD.</p>

Preventive and therapeutic effect of strontium ranelate on osteoporosis in rats subjected to simulated weightlessness / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of strontium ranelate on osteoporosis induced by simulated weightlessness in male rats.</p><p><b>METHODS</b>Twenty-seven male SD rats were randomly divided into 3 groups, namely the normal control group (group A) and two groups of weightlessness simulated by tail suspension (groups B and C). The rats in group C were treated with strontium ranelate, and those in the other two groups were given the same dose of normal saline for 28 consecutive days.</p><p><b>RESULTS</b>The rats in group B showed significantly lower levels of alkaline phosphatase (ALP), bone mineral density (BMD) and bone mineral content (BMC) than those in group A (P<0.05), but serum calcium and phosphonium concentrations underwent no significant changes in the 3 groups (P>0.05). In the rats of group B, the trabeculae of the femur became thinner, fragile, and discontinuous with reduced quantity as compared with those in group A. The rats in group C had greater number of the trabeculae than those in group B with decreased resorption surface and more regular arrangement of the collagen fibers.</p><p><b>CONCLUSION</b>Strontium ranelate may produce beneficial effect on the bone microstructure, reduce bone loss and stimulate bone formation in male rats subjected to simulated weightlessness.</p>

Transcription and promoter hypermethylation of thyroid stimulating hormone receptor gene in human papillary thyroid carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the mRNA expression of the tumor suppressor gene thyroid stimulating hormone receptor (TSHR) gene in papillary thyroid carcinoma (PTC) and the correlation between aberrant promoter methylation of TSHR gene and the tumorigenesis of PTC.</p><p><b>METHODS</b>RT-PCR was used to detect the mRNA expression of TSHR gene in 50 PTC cases, 20 cases of nodular goiter and 12 cases of thyroid adenoma tissue. The status of TSHR gene promoter methylation was determined using methylation-specific PCR technique.</p><p><b>RESULTS</b>Of the 50 PTC patients, 34 (68%) were found to have hypermethylation of TSHR gene promoter region, as compared to 7 out of the 32 control patients (21.9%) positive for TSHR gene promoter hypermethylation, suggesting a significantly higher rate of TSHR promoter methylation of in PTC patients than in the control patients (chi(2) = 16.61, P<0.05). Of the 34 PTC patients with TSHR promoter methylation, 14 (41.2%) showed the absence of TSHR mRNA expression; in the 16 PTC patients without TSHR promoter methylation, only 2 (12.5%) were negative for TSHR mRNA expression, showing a significant difference in the rate of negative TSHR mRNA expression with regard to TSHR promoter methylation. The PTC patients had a significantly lower TSHR mRNA expression than the control patients (chi(2) = 4.02, P<0.05).</p><p><b>CONCLUSION</b>Methylation of TSHR gene in the promoter region is a common molecular event, which might be associated with the tumorigenesis and progression of human PTC.</p>

Protective effect of losartan on insulin secretion function of RIN-m cells against angiotensin II-induced injury and the mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the protective effect of losartan against angiotensin II (AngII)-induced beta cell (RIN-m) impairment and explore its mechanism.</p><p><b>METHODS</b>In vitro cultured RIN-m cells were divided into control group, 100 nmol/L AngII group and losartan pretreatment group. After cell incubation with the corresponding agents for 24 h, the amount of basal (3.3 mmol/L) and glucose-stimulated (16.7 mmol/L) insulin secretion (GSIS) was detected by radioimmunoassay, and the cellular reactive oxygen species (ROS) was assayed by flow cytometry with DCFH-DA staining; the mRNA and protein expressions of uncoupling protein 2 (UCP2) were determined by RT-PCR and Western blotting, respectively.</p><p><b>RESULTS</b>The basal insulin secretion showed no significant differences between the 3 groups (P>0.05). The GSIS in 100 nmol/L AngII group was significantly lower than that of the control group (P<0.001), but losartan pretreatment markedly restored the insulin secretion function to a level comparable to that of the control group (P<0.05). Compared with the control group, 100 nmol/L AngII significantly increased the cellular ROS level and the mRNA and protein expressions of UCP2 (P<0.05), and these changes were eliminated by losartan pretreatment.</p><p><b>CONCLUSIONS</b>Losartan pretreatment offers protective effect against AngII-induced impairment of the GSIS of beta cells possibly by antagonizing the effects of AngII that causes increased ROS level and UCP2 expressions in beta-cells.</p>

Isolation, purification and functional identification of Syrian golden hamster islets / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish the methods for isolation, purification and function identification of Syrian golden hamster islets.</p><p><b>METHODS</b>The Langerhans islets were isolated and purified from golden hamster pancreas by intra-ductal collagenase V perfusion and discontinuous Ficoll density gradient centrifugation. After isolation, the islet yield and purity were evaluated with DTZ staining. The islet function was assessed using glucose-stimulated insulin secretion test.</p><p><b>RESULTS</b>The total number of purified islets from one donor hamster was 359-/+35 islet equivalent (IEQ), with the purity and viability of the isolated islets of more than 90%. In response to glucose stimulations at 5.8 and 16.7 mmol/L, the secretion of insulin by the islets was 3.29-/+0.3 and 11.12-/+0.57 mU/L, respectively, showing a 2.28-fold higher insulin release by high-concentration than by low- concentration glucose stimulation (P<0.01).</p><p><b>CONCLUSION</b>The methods of collagenase V digestion and gradient centrifugation result in high yield and high purity of the isolated hamster islets.</p>

Effects of small interfering RNA targeting connective tissue growth factor on high glucose-induced human tubular epithelial hypertrophy / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of transfection with small interfering RNA (siRNA) targeting connective tissue growth factor (CTGF) on human tubular epithelial hypertrophy induced by high glucose.</p><p><b>METHODS</b>HK-2 cells were cultured in DMEM/F12 medium containing 1 g/L glucose (normal control group), 4.5 g/L glucose (high glucose group), or 1 g/L glucose+3.5 g/L mannitol (iso-osmolar control group). The cells were transfected with pGenesil-1, pGenesil/neg, or pGenesil/siRNA-CTGF and then cultured in DMEM/F12 medium containing 4.5 g/L glucose as the high glucose+blank control group, high glucose+negative control group and high glucose+interference group, respectively. After cell culture for 24, 48 and 96 h, the cells were collected to detect the mRNA and protein levels of CTGF by real-time PCR and Western blotting, respectively. The proliferative activities of the cells were evaluated with MTT assay, and the total cellular protein contents were determined with Bradford method. Flow cytometry was employed to analyzed the cell cycle changes.</p><p><b>RESULTS</b>High-glucose significantly up-regulated the CTGF mRNA and protein levels in HK-2 cells. The cell proliferation was inhibited after high-glucose exposure with increased cell percentage in G1 phase and total cellular protein content suggesting cellular hypertrophy. Transfection with siRNA targeting CTGF significantly inhibited high glucose-induced up-regulation of CTGF mRNA and protein and promoted the cell proliferation, resulting also increased cells in S phase and lowered total cellular protein contents.</p><p><b>CONCLUSION</b>CTGF is an important mediator of high glucose-induced tubular epithelial hypertrophy, and transfection with siRNA targeting CTGF can alleviate the hypertrophy, suggesting the potential value of CTGF-targeted treatment in the management of diabetic nephropathy.</p>

Effect of high glucose exposure on connective tissue growth factor expression in cultured human renal tubular epithelial cells and the role of p38MAPK pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of high glucose exposure on connective tissue growth factor (CTGF) expression in cultured human renal tubular epithelial cells and investigate the role of p38MAPK pathway in this process.</p><p><b>METHODS</b>Human renal tubular epithelial cells (HKC) with and without SB203580 pretreatment were cultured in the presence of high glucose levels for 24, 48, 72, 96 h and 20 days. RT-PCR, immunohistochemical staining, indirect fluorescence staining and Western blotting were used to detect the changes in CTGF mRNA and protein expressions in the cells after the treatment.</p><p><b>RESULTS</b>Low levels of CTGF mRNA and protein were detected in cultured HKC cells, and after high glucose treatment, the mRNA expression increased gradually and reached the peak level at 48 h, then followed by gradual decrease till recovering the baseline level at 96 h. Prolonged high glucose treatment for 20 days resulted in persisted high CTGF mRNA expression twice the level in the control group. The expression level of CTGF protein also increased progressively as the treatment time then prolonged, and long-term (20 days) treatment increased the expression by 4 folds in comparison with the expression in the control cells. SB203580 significantly inhibited the increase in the expressions of CTGF mRNA and protein stimulated by high glucose treatment.</p><p><b>CONCLUSION</b>High glucose treatment can increase CTGF mRNA and protein expressions in cultured human renal tubular epithelial cells, suggesting that increased CTGF levels is a key event in the pathogenesis of renal tubulo-interstitial fibrosis in patients with diabetic nephropathy. p38MAPK pathway may also participate in this process.</p>

An infrared imaging system for detecting electrophoretic mobility shift of DNA-protein complexes / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a new non-radioactive method for electrophoretic mobility shift assay (EMSA) to investigate the binding between glucocorticoid induced leucine zipper (GILZ) and peroxisome proliferator-activated receptor-gamma 2 (PPARgamma2) promoter oligonucleotides.</p><p><b>METHODS</b>GILZ protein prepared by prokaryotic expression was linked to PPARgamma2 promoter oligonucleotides end-labeled with IRDye 800 infrared dye. The DNA-protein complex was separated with non-denatured polyacrylamide gel and scanned with the Odyssey. Infrared Imaging System.</p><p><b>RESULTS</b>One lane of DNA-protein complex was clearly presented, and the signal intensity increased along with the increment of the protein load.</p><p><b>CONCLUSION</b>This infrared imaging system can be used for EMSA for detecting the DNA-protein complex with high sensitivity efficiency and allows easy operation.</p>

Inadequate glycaemic control and antidiabetic therapy among inpatients with type 2 diabetes in Guangdong Province of China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Diabetes mellitus has become epidemic in recent years in China. We investigated the prevalence of hyperglycaemia and inadequate glycaemic control among type 2 diabetic inpatients from ten university teaching hospitals in Guangdong Province, China.</p><p><b>METHODS</b>Inadequate glycaemic control in diabetic patients was defined as HbA1c = 6.5%. Therapeutic regimens included no-intervention, lifestyle only, oral antiglycemic agents (OA), insulin plus OA (insulin + OA), or insulin only. Antidiabetic managements included monotherapy, double therapy, triple or quadruple therapy.</p><p><b>RESULTS</b>Among 493 diabetic inpatients with known history, 75% had HbA1c = 6.5%. Inadequate glucose control rates were more frequently seen in patients on insulin + OA regimen (97%) than on OA regimen (71%) (P < 0.001), and more frequent in patients on combination therapy (81% - 96%) than monotherapy (75%) (P < 0.05). Patients on insulin differed significantly from patients on OA by mean HbA1c, glycemic control rate, diabetes duration, microvascular complications, and BMI (P < 0.01).</p><p><b>CONCLUSIONS</b>This study showed that glycaemic control of type 2 diabetic patients deteriorated for patients who received insulin and initiation time of insulin was usually delayed. It is up to clinicians to move from the traditional stepwise therapy to a more active and early combination antidiabetic therapy to provide better glucose control.</p>

Effects of Chinese Bushen Zhuanggu medicine on bone loss in female rats after simulated weightlessness / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of Bushen Zhuanggu, the traditional Chinese medicine for reinforcing kidney and strengthening bone, on bone loss in female rats after simulated weightlessness.</p><p><b>METHOD</b>Thirty-six female SD rats were randomly divided into 3 groups, namely normal control group (group A) and two groups of weightlessness simulated by tail suspension (groups B and C). Group C were treated with the Chinese medicine, while groups A and B were given the same dose of normal saline. The experiment lasted 28 days, and all rats were allowed to drink water freely.</p><p><b>RESULTS</b>In the rats of group B, serum bone Gla protein (BGP), alkaline phosphatase (ALP), estradiol (E(2)) and P content and femur bone mineral content (BMD) were significantly lower than those in group A (P<0.01, P<0.05), whereas serum calcium concentration was markedly higher than that in group A (P<0.01). In rats of group C, serum BGP, ALP, E2 and P content and femur BMD were significantly higher than those in group B (P<0.01, P<0.05), but serum calcium concentration was markedly lower (P<0.01).</p><p><b>CONCLUSION</b>This Chinese prescription can stimulate bone formation and reduce bone loss in female rats subjected to simulated weightlessness.</p>

Comparison of continuous and discontinuous density gradient centrifugation for purification of human pancreatic islets / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the effect of continuous and discontinuous density gradient centrifugation for purification of human pancreatic islets with COBE 2991 cell processor.</p><p><b>METHODS</b>Human pancreases were obtained from brain-dead donors and stored in cold UW solution. The connective tissues were removed from the pancreases, and the pancreatic ducts were perfused with a cold enzyme (Liberase). The islets were then separated by gentle mechanical dissociation and purified with discontinuous (10 pancreases) or continuous (8 pancreases) gradients of HCA-Ficoll in COBE 2991 cell processor. Samples were collected in duplicate for determination of the quantity of islets, islet equivalents (IEQ), and the purity.</p><p><b>RESULTS</b>The weights of the pancreases before and after connective tissue removal and pancreas duct perfusion, and the quantity of islets obtained (including islets quantity of different diameters and total IEQ) after dissociation were not significantly different. Continuous gradient of HCA-Ficoll, compared with discontinuous gradient, resulted in significantly greater final islet quantity (55,000 IEQ vs 206,000 IEQ, P=0.000) and islet purity (58.0%-/+8.0% vs 33.5%-/+10.3%, P=0.000) and also greater number of islets with a diameter lager than 200 microm (P<0.01).</p><p><b>CONCLUSION</b>Continuous density gradient centrifugation can be more effective than discontinuous gradient in islet purification.</p>

Effects of Chinese herbal medicine for supplementing Shen and strengthening the bone on rat distal femur cancellous bone in simulated weightlessness: an observation with scanning electron microscope / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of Chinese herbal medicine for supplementing Shen and strengthening the bone on distal femoral trabecular ultrastructure of male rats subjected to simulated weightlessness.</p><p><b>METHODS</b>Fifteen male SD rats were randomized equally into 3 groups, including a control group (group A, in which the rats were allowed free movement) and two simulated weightlessness (via tail suspension) groups (group B and C). The rats in group C were treated with the commercially available Chinese herbal preparation, and those in the other two groups received normal saline at the same dose, for a treatment course of 28 days. Observation of trabeculae was performed with scanning electron microscopy.</p><p><b>RESULTS</b>In group B, the trabeculae of the femur became thinner, fragile, discontinuous with reduced quantity as compared with those in group A. The rats in group C had greater number of the trabeculae than those in group B. Resorption surface decreased and the collagenous fiber were much more regular in group B.</p><p><b>CONCLUSION</b>The Chinese herbal medicine may produce beneficial effect on bone microstructure of rats subjected to simulated weightlessness.</p>

Isolation and purification of human islet cells with semi-automated digestion / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an semi-automated effective method for large-scale purification of islet cells from human pancreas.</p><p><b>METHODS</b>Human pancreas tissue was digested with collagenase P using a semi-automated pancreas-digestion system followed by purification in a HCA-Ficoll continuous gradient using Cobe2991 cell separator. After isolation, the islet cell yield and purity was evaluated with light microscope with DTZ staining, and the islet function assessed by insulin release assay in vitro.</p><p><b>RESULTS</b>The number of the islets collected from each pancreas averaged 38 6201-/+78 219 islet equivalents (IEQ) before purification, and 231 420-/+28 054 IEQ after the purification with discontinuous gradient centrifugation. From each gram of the pancreatic tissue, 3148-/+317 IEQ were obtained with an average purity of (62.81-/+2.68) %. The purified islets responded well to high-concentration (16.7 mmol/L) glucose stimulation with a 2.53-fold increase of insulin secretion over the basal level (3.3 mmol/l, P<0.001).</p><p><b>CONCLUSION</b>The established semi-automated method can be applicable for large-scale purification of fully functional islet cells from human pancreas.</p>