Case report: Diabetic muscle infarction with diabetic ketoacidosis: A rare complication of diabetes.

Background: Diabetic muscle infarction (DMI), which is also referred to as diabetic myonecrosis, is a rare and long-term complication of poorly controlled diabetes mellitus, while we found that acute diabetes decompensation, such as diabetic ketoacidosis (DKA), could also stimulate the occurrence and development of DMI. Case presentation: A 23-year-old woman with type 1 diabetes presented with a 10-day history of nausea, vomiting, pain, and swelling of her left leg. Her urine ketone test was positive. The 3-beta-hydroxybutyrate and leukocyte counts and creatine kinase levels were elevated. Magnetic resonance imaging of the left thigh revealed extensive deep tissue oedema and an increase in the T2 signal in the involved muscles. Once the diagnosis of DMI was made, she was managed with rest, celecoxib, clopidogrel and aggressive insulin therapy. Three months after treatment, the patient reported complete resolution of symptoms. Conclusion: DMI is a rare DM complication with a high recurrence rate, commonly presenting with chronic complications, while our case report shows that acute diabetes decompensation, such as DKA, can stimulate the occurrence and development of DMI. Timely diagnosis and appropriate treatment could shorten the recovery time.

Observation of elevated fasting blood glucose and functional outcome after ischemic stroke in patients with and without diabetes.

During May 2015 to October 2016, this prospective study enrolled a total of 438 patients with acute ischemic stroke(AIS), meanwhile, records regarding the severity of initial stroke and neurological outcomes at three months, as well as other examination were completed in patients on admission, as well as the measurement and evaluation of fasting blood glucose(FBG) levels. At admission, the median FBG levels in patients with a minor stroke (n=124), [P<0.001]) was significantly lower than that observed in patients with other degrees of stroke. The poor functional outcome distribution across the FBG quartiles ranged from 13.8 % (first quartile) to 59.6% (fourth quartile), with P <0.001. Compared with the reference category (first quartile), patients in the highest quartile had a relative risk of 3.12 (95% confidence interval [CI], 1.88-6.15; P<0.001) while those in the second and third quartiles had relative risks of 1.76 (95% CI, 1.21-3.03; P=0.035) and 2.23 (95% CI, 1.50-3.69; P=0.010), respectively. Furthermore, in the patients without diabetes, FBG level was observed to be increased and indicated an increased risk of disability (odds ratio [OR]: 1.30 (95%CI 1.13-1.61), P=0.002), however, similar result was not detected in patients with prior diabetes (P=0.089). In conclusion, elevated FBG levels after stroke may suggest poor functional outcome at 3-month in patients without a previous history of diabetes.

Effects of probiotics supplement in patients with type 2 diabetes mellitus: A meta-analysis of randomized trials. / Efectos del suplemento de probióticos en pacientes con diabetes mellitus tipo 2: metaanálisis de ensayos aleatorizados.

BACKGROUND AND OBJECTIVE: To objectively evaluate the effects of probiotics supplement on glycemic control and lipid metabolism in patients with type 2 diabetes mellitus (T2DM). MATERIAL AND METHODS: The randomized controlled trials (RCTs) with regard to the probiotics or synbiotics for the treatment of T2DM were collected through retrieving 5 databases from their establishment to March 2016. After study selection, quality assessment and data extraction were performed by 2 authors independently; and STATA software was used for statistical analysis. The level of evidence was evaluated by applying the GRADE system. RESULTS: Twelve RCTs involving 770 participants were enrolled. The results of the meta-analysis showed that probiotics could significantly reduce fasting blood glucose by -11.27mg/dL (95% CI -21.76 to -0.79; P<.001) and serum insulin concentration by -2.36µU/mL (95% CI -4.01 to -0.72; P=.005), but with no significant reduction on HbA1c (-0.19%; 95% CI -0.49 to 0.12; P=.23). Probiotics could significantly reduce HOMA-IR of T2DM patients (-1.05; 95% CI -1.52 to -0.59; P<.001). Nevertheless, the effect on QUICKI was negligible (0.00; 95% CI -0.00 to 0.01; P=.27). Results also confirmed the significant lowering effect of probiotics on total cholesterol (-8.49mg/dL; 95% CI -15.24 to -1.73; P=.014) and triglycerides (TG; -23.66mg/dL; 95% CI -40.26 to -7.05; P<.001), as well as the elevating effect on HDL-c (3.92mg/dL; 95% CI 2.14 to5.7; P<.01). However, there was no significant change on LDL-c (-0.84mg/dL; 95% CI -5.84 to 4.17; P=.75). Subgroup analysis was conducted for 2 outcomes, that is, serum insulin concentration and TG, whose heterogeneity was too high. The results showed multiple species of probiotics had stronger reduction effect on serum insulin concentration (-3.32µU/mL; 95% CI -5.89 to-0.75; P=.001) and TG (-25.94mg/dL; 95% CI -65.33 to 13.44; P<.001). In addition, it also suggested that only the duration of treatment for≥8 weeks could significantly reduce TG by -24.47mg/dL (95% CI -40.15 to -8.78; P=.001). The duration of treatment for<8 weeks didn't result in significant reduction on TG (-4.31mg/dL; 95% CI -37.69 to 29.06; P=.8). Finally, all the evidences were at moderate and low levels according to the GRADE system. CONCLUSION: As a kind of the potential biotherapeutics in the management of T2DM, probiotics can improve glucose control and lipid metabolism.

Melatonin protects podocytes from angiotensin II-induced injury in an in vitro diabetic nephropathy model.

Diabetic nephropathy (DN) is a severe renal disorder characterized by podocyte damage and accumulation of extracellular matrix leading to further glomerulosclerosis, possibly via the activation of inflammatory signaling and the generation of oxidative stress. Melatonin has been considered a robust anti­oxidant, and is able to attenuate DN in several animal models. In the present study, cell viability was examined by CCK-8 assay. Cell apoptosis, intracellular reactive oxygen species and mitochondrial membrane potential (MMP) levels were measured by flow cytometry. Western blot analysis was performed to detect the expression of Nephrin, B cell lymphoma­2 (Bcl­2)­associated X protein (Bax), Bcl-2, Caspase-3, Janus kinase (JAK)2 and Signal transducer and activator of transcription (STAT)3 in podocytes. Based on an in vitro podocyte injury model, the present study found that the application of melatonin significantly reduced AngII­induced apoptosis and increased the proliferative rate of cells, as evidenced by decreased expression levels of apoptotic proteins, including Caspase­3 and Bax, and a change in the ratio of Bax/Bcl­2. Further investigation demonstrated that a reduction in oxidative stress and the recovery of mitochondrial function were involved in this protective effect. In addition, the Jak/STAT signaling pathway was inhibited, indicating that cytokine­mediated inflammation was also targeted by melatonin. The present study demonstrated for the first time, to the best our knowledge, that melatonin exerted an anti-apoptotic effect in AngII-mediated podocyte injury, and indicates a possible mechanism to explain the protective effect of melatonin in DN.

Associations between endothelial nitric oxide synthase polymorphisms and risk of diabetic nephropathy: an updated meta-analysis.

BACKGROUND: Genetic polymorphism of endothelial nitric oxide synthase (eNOS) has been implicated in the risk of diabetic nephropathy (DN), but the published findings were inconsistent. We performed a comprehensive meta-analysis to derive a more precise estimation of the association between genetic polymorphisms of eNOS and the risk of DN. METHODS: Six online database were researched on the associations between polymorphisms of eNOS (T786C, G894T, 4b/4a) and DN risk. PRISMA statement and Hardy-Weinberg equilibrium assessment were used in this report. Odds ratio and 95% confidence interval were estimated based on the following genetic contrast/models: allelic model, dominant model, recessive model and co-dominant model. The publication bias and sensitivity analysis were also performed to guarantee the statistical power. RESULTS: A total of 49 case-control studies with 11,990/9754/5131 participants for DN/DM/HC group were eligible for meta-analysis (7/25/31 studies for T786C/G984T/4b/a). For the eNOS-T786C, C allele showed a weak association between C allele and DN risk in DN/T2DM group. For eNOS-G894T, there was an association between T allele and DN risk in the global, Asian and African population in DN/T2DM group. For the eNOS-4b/4a, 4a allele was found contributing significantly to increased DN risk in the global population. CONCLUSION: Our comprehensive meta-analysis suggests that three polymorphisms of eNOS may be the increased risk factors of DN development, especially in Asian population and T2DM group.

Differential expression and therapeutic efficacy of microRNA-346 in diabetic nephropathy mice.

Diabetic nephropathy (DN) is a major cause of end-stage renal disease, in which the SMAD signaling pathway plays an important role. The aim of the present study was to identify differentially expressed microRNAs (miRNAs) during the progression of DN and to investigate a selected miRNA in relation to SMAD3/4 and its therapeutic efficacy. The miRNA microarray was used to identify differentially expressed miRNAs in db/db DN mice. Reverse transcription-quantitative polymerase chain reaction and immunoblot analyses were used to detect SMAD3/4 expression. The development of DN in the db/db mice was demonstrated by glucose dysregulation and typical morphological changes in the kidney. miRNA-346 (miR-346) was identified as one of the differentially expressed miRNAs. The expression of SMAD3/4 was significantly attenuated by miR-346 administration and the therapeutic effects of miR-346 were observed in the DN mouse models. miR-346 was identified as a negative regulator of SMAD3/4. SMAD3/4 was upregulated in the renal tissue of db/db mice. The administration of miR-346 attenuated the SMAD3/4 expression in renal tissue and ameliorated the renal function and glomerular histology in DN mice. This study paves the way for clinical studies of miR-346 in DN.

Elevated urinary level of vitamin D-binding protein as a novel biomarker for diabetic nephropathy.

Improving the early prediction and detection of diabetic nephropathy (DN) remains a great challenge in disease management. The aim of this study was to evaluate the early detection power of urinary vitamin D-binding protein (VDBP) for the diagnosis of DN. Urine samples were obtained from 45 healthy volunteers and 105 diabetic patients with normoalbuminuria (DM group), microalbuminuria (DN1 group) and macroalbuminuria (DN2 group) (n=35 per group). The VDBP expression patterns in urine from patients and controls were quantified by western blot analysis. The excretion levels of urinary VDBP were quantified with enzyme-linked immunosorbent assay. The quantification results were obtained by correcting for creatinine expression and showed that urinary VDBP levels were significantly elevated in the patients of the DN1 and DN2 groups compared with those of the DM group and normal controls (1,011.33±325.30 and 1,406.34±239.66 compared with 466.54±213.63 and 125.48±98.27 ng/mg, respectively) (P<0.001). Receiver operating characteristic analysis of urinary VDBP levels for the diagnosis of DN rendered an optimum cut-off value of 552.243 ng/mg corresponding to 92.86% sensitivity and 85.00% specificity, which also showed an area under the ROC curve of 0.966. In conclusion, the findings of the present study suggest that urinary VDBP may be a potential biomarker for the early detection and prevention of DN. Further studies are required to examine the pathogenic mechanisms of elevated VDBP levels and their role in the diagnosis of DN.

Vascular endothelial growth factor gene polymorphisms and renal cell carcinoma: A systematic review and meta-analysis.

Renal cell carcinoma (RCC) accounts for 3% of all cancer-related mortalities in adults. The risk factors for the development of RCC remain under investigation. Vascular endothelial growth factor (VEGF) is a key mediator of angiogenesis and is crucial for the development and metastasis of tumors, including RCC. VEGF gene polymorphisms may alter VEGF protein concentrations, affect the process of angiogenesis and may be involved in inter-individual variation in carcinogenesis. In the present study, a systematic review and meta-analysis were performed based on published case-control studies in order to estimate the association between VEGF gene polymorphisms and the susceptibility to RCC. A total of five studies that involved eight polymorphisms and were published between January 2000 and December 2012 were identified from PubMed. The results of this systematic review and meta-analysis indicate that the VEGF 936C/T, 1612G/A, -1154G/A, -2549I/D, -460T/C and 405G/C gene polymorphisms are not associated with the risk of RCC. There was no polymorphism in 702C/T and RCC and the -2578C/A gene polymorphism may be associated with an increased risk of RCC. However, due to the limitations of the present study, further high quality case-control studies are warranted to confirm these findings.

Glycemic control among patients in China with type 2 diabetes mellitus receiving oral drugs or injectables.

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) is increasing rapidly among Chinese adults, and limited data are available on T2DM management and the status of glycemic control in China. We assessed the efficacy of oral antidiabetes drugs (OADs), glucagon-like peptide-1 (GLP-1) receptor agonists, and insulin for treatment of T2DM across multiple regions in China. METHODS: This was a multicenter, cross-sectional survey of outpatients conducted in 606 hospitals across China. Data from all the patients were collected between April and June, 2011. RESULTS: A total of 238,639 patients were included in the survey. Eligible patients were treated with either OADs alone (n=157,212 [65.88%]), OADs plus insulin (n=80,973 [33.93%]), or OADs plus GLP-1 receptor agonists (n=454 [0.19%]). The OAD monotherapy, OAD + insulin, and OAD + GLP-1 receptor agonist groups had mean glycosylated hemoglobin (HbA1c) levels (±SD) of 7.67% (±1.58%), 8.21% (±1.91%), and 7.80% (±1.76%), respectively. Among those three groups, 34.63%, 26.21%, and 36.12% met the goal of HbA1c <7.0%, respectively. Mean HbA1c and achievement of A1c <7.0% was related to the duration of T2DM. CONCLUSIONS: Less than one third of the patients had achieved the goal of HbA1c <7.0%. Glycemic control decreased and insulin use increased with the duration of diabetes.

Vitamin D intake and type 2 diabetes risk: a meta-analysis of prospective cohort studies.

BACKGROUND: The findings form studies on the relationship between vitamin D and type 2 diabetes were inconsistent. OBJECTIVES: To elucidate the association between vitamin D consumption and type 2 diabetes risk by conducting a meta-analysis. METHODS: We conducted a systematic literature search to identify prospective cohort studies of vitamin D intake and type 2 diabetes risk prior to November 2012. Eligible studies were retrieved via both computer searches and manual review of references. The summary risk estimates were calculated based on the highest versus the lowest categories. RESULTS: Meta-analysis of 4 prospective cohort studies involving 187, 592 participants and 9, 456 incident cases showed an absence of significant association between total vitamin D intake and type 2 diabetes risk. The combined RR was 0.93 (95% CI: 0.85-1.01). The associations were similar for subgroup analyses, a combined RR respectively was 0.94 (95% CI: 0.77-1.08), 0.91 (95% CI: 0.77-1.08), 0.93 (95% CI: 0.84-1.02), and 0.92 (95% CI: 0.84-1.01) for the intake of dietary vitamin D, supplemental vitamin D, total vitamin D in USA and total vitamin D for women only. CONCLUSIONS: Our results support that there was no association between vitamin D intake and type 2 diabetes.

[A cross-sectional study on serum uric acid level and the distribution of metabolic syndrome among Uigur, Han and Kazak prediabetic groups in Xinjiang].

OBJECTIVE: To explore the levels of uric acid, blood pressure, serum lipid metabolic disorders and the distribution of obesity and metabolic syndrome (MS) among Uygur, Han and Kazak pre-diabetic groups in Xinjiang. METHODS: A cross-sectional study was conducted on 2053 Uygur residents, 2219 Kazak residents and 2656 Han residents aged 30-80, all with prediabetic syndromes. The pre-dialectic patients were divided into three groups for analysis on metabolic features and inter-group comparisons. RESULTS: (1)In total, 1934 pre-diabetic cases (28.3%)were diagnosed, with the highest prevalence (31.6%) seen in Uygurs and the lowest (25.5%) in Kazaks and medium (27.0%) in Hans. Data from the inter-group comparison showed statistically significant differences (P = 0.00). (2)Prevalence of high LDL-C was 80.5% , with hyperuricemia as 30.3% and MS as 58.3% , while the inter-group comparison did not show any statistically significant differences (P > 0.05). (3) Prevalence of pre-diabetic when combined with hypertension or earlier-stage hypertension, reached 88.0%, with the highest (96.8%) among Kazak group, 85.1% in Uygurs and 83.7% in Han population. Data from the inter-group comparison showed statistically significant difference(χ(2) = 59.959, P = 0.00). (4)The overall prevalence of prediabetic, when combined with obesity was 35.4%, with 29.6% in Han, 36.8% in Uygur and 41.0% in Kazak groups. Data from the inter-group comparison showed statistically significant difference(χ(2) = 19.097, P = 0.00). CONCLUSION: According to results from this cross-sectional study regarding the metabolic features of Uygur, Kazak and Han prediabetic groups, differences were seen in the prevalence rates of pre-diabetic among Uygur, Kazak and Han ethnic groups, with the highest seen in Uygurs and the lowest in Kazaks. Hyperlipidemia, hypertension, hyperuricemia,MS and obesity were commonly seen in all the prediabetic groups, with the highest prevalence of hypertension seen in the Kazak group and the highest rate of obesity in Uygur group.

[Improvement in blood glucose fluctuations of insulin-treated type 1 diabetic patients with additional use of acarbose and assessed by continuous blood glucose monitoring program].

OBJECTIVE: To investigate the effect of combined use of insulin and acarbose on glucose excursion in type 1 diabetic patients. METHODS: 120 cases were randomly divided into control group and observation group. The control group received preprandial ultra-short effect insulin and long-acting insulin before bedtime while the observation group received acarbose 50 mg added to the medicine taken by the control group. Continuous Glucose Monitoring System (CGMS) was used to watch the blood glucose fluctuations. Data related to blood glucose level, glucose excursions after meals and hypoglycemia at night were compared between patients in the two groups. RESULTS: The average blood glucose (9.37 ± 1.70) mmol/L, the largest amplitude of glycemic excursions (LAGE) (11.42 ± 2.73) mmol/L, hyperglycemia-area under curve 0.89 ± 0.54, mean amplitude of glycemic excursions (MAGE) (5.13 ± 2.23) mmol/L, M-value (18.93 ± 11.43) mmol/L and insulin dosage (42.11 ± 14.42) U/day of observation group were significantly lower than in the control group (P < 0.05). Glucose excursions after meals and the times (0.33 ± 0.50)/day, the maintenance time (43.75 ± 43.50)/min and low glycemic index (LBGI) (0.005 ± 0.002) mmol/L of hypoglycemia at night were also significantly lower than in the control group, with statistically significant (P < 0.05) differences. CONCLUSION: The blood glucose fluctuation was significantly improved, with the decrease of insulin dosage while both glucose excursions and hypoglycemia at night reduced in patients with type1 diabetes mellitus after the acarbose treatment.We suggested that this program deserve further observation.

[Secretion and action of insulin among Han and Uygur subjects with impaired fasting glucose and impaired glucose tolerance from Xinjiang].

OBJECTIVE: To compare insulin secretion and action with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and combined glucose intolerance (CGI, IFG and IGT) between Han and Uygur populations living in Xinjiang. METHODS: A multicenter cross-section survey (The Third Diabetes Epidemiological Survey in China) was conducted in Xinjiang from 2007 to 2008 including 2203 subjects (Han 1118, Uygur 1085) underwent an oral glucose test (OGTT). Homeostasis model assessment on insulin resistance (HOMA-IR) and ß cell function (HOMA-ß) were calculated. The ratio of incremental insulin (ΔI30) and glucose (ΔG30) response was used to evaluate the early insulin secretion. ΔI30/ΔG30/HOMA-IR was used to evaluate the glucose disposition index (DI). RESULTS: There were differences noticed regarding the waist circumstances (WC), body mass index (BMI), lipids, 0 and 120 min insulin levels in different glucose tolerance status between the Hans and Uygurs. Data related to NGT, IFG, CGI, WC from the Uygurs was significantly different from that of the Hans (P < 0.01), while the NGT, IFG, IGT and 120-minute plasma insulin levels of the Hans were significantly different from that of the Uygurs (P < 0.01). HOMA-IR and HOMA-ß in Hans were significantly different from those of the Uygurs (P < 0.01). There were significant differences noticed on data related to ΔI30/ΔG30, and DI among the two populations with different ethnicities. CONCLUSION: Regarding the regulation of impaired glucose, the insulin resistance among the Hans was significantly different from that of the Uygurs, while there seemed to be a compensatory secretion of pancreatic ß cells which played the role of maintaining blood glucose homeostasis.

A new tumor necrosis factor (TNF)-α regulator, lipopolysaccharides-induced TNF-α factor, is associated with obesity and insulin resistance.

BACKGROUND: Tumor necrosis factor (TNF)-α plays an important role in mediating inflammatory state in obesity and related disorders. Lipopolysaccharides (LPS)-induced TNF-α factor (LITAF) is recently verified as a regulator of TNF-α and other inflammatory cytokines, and maybe act as a transcriptional factor. The aim of this study was to confirm the association between LITAF and obesity and insulin resistance. METHODS: Forty-seven subjects with a wide range of body mass index (BMI) were included. Subjects were divided into three groups according to the criteria of normal weight, overweight and obese. Anthropometrics and metabolic profile were tested for all the subjects. Peripheral monocytes were isolated and purified. LITAF transcription was detected by real time PCR, and the protein expression in whole cell and nucleus extracts was detected by Western blotting analysis; transcriptional activity of LITAF was detected by ELISA like assay using a probe containing the DNA binding sequence of LITAF. Plasma TNF-α and interleukin (IL)-6 concentrations were determined with ELISA kit. RESULTS: The LITAF mRNA and protein expression in whole cell were higher in overweight (P < 0.05) and obese group (P < 0.05) compared with that in normal weight group. The LITAF protein expression in the nucleus and transcriptional activity could not be detected. LITAF protein expression was positively correlated with BMI (r = 0.541, P < 0.001), waist circumference (r = 0.391, P = 0.007), the homeostasis model assessment for insulin resistance (r = 0.372, P = 0.011) and fasting insulin levels (r = 0.359, P = 0.013). As a regulator of inflammatory cytokines, LITAF protein expression was positively correlated with plasma TNF-α (r = 0.621, P = 0.002) and IL-6 (r = 0.407, P = 0.039) concentration. Multiple variant regression analysis indicated that BMI (P = 0.002) and waist circumference (P = 0.017) were independent predictors of LITAF protein expression. CONCLUSIONS: LITAF is associated with obesity and insulin resistance, as well as inflammatory cytokine secretion. The results indicate LITAF to be a new mediator between inflammation and the obesity related disorders.

Anti-diabetic effects of cinnamaldehyde and berberine and their impacts on retinol-binding protein 4 expression in rats with type 2 diabetes mellitus.

BACKGROUND: Retinol binding protein 4 (RBP4), as an adipocyte secreted cytokine, was recently found to be inversely correlated with expression of glucose transporter 4 (GLUT4) in insulin resistance (IR) state and to have an intimate relationship with IR and type 2 diabetes mellitus (T2DM). The present study aimed to evaluate the anti-diabetic efficacy of cinnamaldehyde (Cin), berberine (Ber), and metformin (Met) as well as their impacts on the RBP4-GLUT4 system. METHODS: Rat models of T2DM were established by combination of intraperitoneal injection of low-dose streptozotocin and high fat diet induction. Rats were divided into five groups: the control group, the diabetes group, the diabetes + Ber group, the diabetes + Cin group, and the diabetes + Met group. Western blotting was used to detect the serum or tissue RBP4 and GLUT4 protein levels. RESULTS: After treatment for four weeks, both Cin and Ber displayed significant hypolipidemic, hypoglycemic, and insulin sensitizing functions (P < 0.01) compared with the control group. Their effects on lowering fasting plasma glucose (FPG), low density lipoprotein-cholesterol (LDL-C) and homeostasis model assessment of insulin resistance (HOMA-IR) seem even better than that of Met. Cin and Ber markedly lowered serum RBP4 levels and up-regulated the expression of tissue GLUT4 protein, and Cin seemed more notable in affecting these two proteins. CONCLUSIONS: Both Cin and Ber display an exciting anti-diabetic efficacy in this study and may be of great value for the treatment of type 2 diabetes. Their mechanisms involve the RBP4-GLUT4 system, during which the serum RBP4 levels are lowered and the expression of tissue GLUT4 protein is up-regulated.

Expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats.

AIM: To study the expression of human insulin gene wrapped with chitosan nanoparticles in NIH3T3 cells and diabetic rats. METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, was constructed. In total, 100 microg pCMV.Ins wrapped with chitosan nanoparticles (chitosan-pCMV.Ins) was transfected to NIH3T3 cells and diabetes rats through lavage and coloclysis, respectively. The transfected cells were grown in Dulbecco's modified Eagle's medium, containing G418, for 72 h after transfection. The clones were selected and continued to grow in G418 medium for 24 d. The expression of human insulin was detected by immunohistochemistry. Human insulin in the culture medium of transfected cells was measured. Fasting blood glucose and plasma human insulin of diabetic rats were measured for 5 d after transfection. RT-PCR and Western blotting were performed to confirm the expression of the human insulin gene in diabetic rats. RESULTS: Approximately 10% of NIH3T3 cells transfected by chitosan-pCMV.Ins expressed human insulin. Human insulin in the culture medium of NIH3T3 cells transfected by chitosan-pCMV.Ins significantly increased compared with that of the control group (P<0.01). Fasting blood glucose levels of the lavage group and the coloclysis group decreased significantly in 5 d (P<0.01) in comparison, while plasma insulin levels were much higher (P<0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and the coloclysis groups. CONCLUSION: The human insulin gene can be transfected and expressed successfully by chitosan- pCMV.Ins in NIH3T3 cells and diabetes rats, which indicates that chitosan is a promising, non-viral vector for gene expression.

Gene therapy for type 1 diabetes mellitus in rats by gastrointestinal administration of chitosan nanoparticles containing human insulin gene.

AIM: To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats. METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected to the diabetic rats through lavage and coloclysis, respectively. Fasting blood glucose and plasma insulin levels were measured for 7 d. Reverse transcription polymerase chain reaction (RT-PCR) analysis and Western blot analysis were performed to confirm the expression of human insulin gene. RESULTS: Compared with the control group, the fasting blood glucose levels in the lavage and coloclysis groups were decreased significantly in 4 d (5.63 +/- 0.48 mmol/L and 5.07 +/- 0.37 mmol/L vs 22.12 +/- 1.31 mmol/L, respectively, P < 0.01), while the plasma insulin levels were much higher (32.26 +/- 1.81 microIU/mL and 32.79 +/- 1.84 microIU/mL vs 14.23 +/- 1.38 microIU/mL, respectively, P < 0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and coloclysis groups. CONCLUSION: Human insulin gene wrapped with chitosan nanoparticles can be successfully transfected to rats through gastrointestinal tract, indicating that chitosan is a promising non-viral vector.

Obesity and colorectal cancer risk: a meta-analysis of cohort studies.

AIM: To evaluate the association between obesity and colorectal cancer risk. METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to January 1, 2007. Cohort studies permitting the assessment of causal association between obesity and colorectal cancer, with clear definition of obesity and well-defined outcome of colorectal cancer were eligible. Study design, sample size at baseline, mean follow-up time, co-activators and study results were extracted. Pooled standardized effect sizes were calculated. RESULTS: The pooled relative risk (RR) of colorectal cancer was 1.37 (95% CI: 1.21-1.56) for overweight and obese men, 1.07 (95% CI: 0.97-1.18) for women measured by body mass index (BMI). The pooled RR for the highest vs the lowest quantiles of BMI was 1.59 (95% CI: 1.35-1.86) for men and 1.22 (95% CI: 1.08-1.39) for women at risk of colon cancer, 1.16 (95% CI: 0.93-1.46) for men and 1.23 (95% CI: 0.98-1.54) for women at risk of rectal cancer. The pooled RR for the highest vs the lowest quantiles of waist circumference was 1.68 (95% CI: 1.36-2.08) for men and 1.48 (95% CI: 1.19-1.84) for women at risk of colon cancer, 1.26 (95% CI: 0.90-1.77) for men and 1.23 (95% CI: 0.81-1.86) for women at risk of rectal cancer. The pooled RR for the highest quantiles vs the lowest quantiles of waist-to-hip ratio was 1.91 (95% CI: 1.46-2.49) for men and 1.49 (95% CI 1.23-1.81) for women at risk of colon cancer, 1.93 (95% CI: 1.19-3.13) for men and 1.20 (95% CI: 0.81-1.78) for women at risk of rectal cancer. Compared with 'normal range', the pooled RR for proximal colon cancer was 1.14 (95% CI: 0.88-1.47) for the overweight and 1.41 (95% CI: 0.66-3.01) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 2.05 (95% CI: 1.23-3.41) with waist circumference, 1.66 (95% CI: 0.69-3.99) with waist-to-hip ratio. Compared with 'normal range', the pooled RR for distal colon cancer was 1.38 (95% CI: 1.02-1.87) for the overweight and 1.23 (95% CI: 0.80-1.90) for the obese. The pooled RR for the highest quantiles vs the lowest quantiles was 1.86 (95% CI: 1.05-3.30) with waist circumference, and 1.79 (95% CI: 0.82-3.90) with waist-to-hip ratio. CONCLUSION: Obesity is a statistically significant risk factor for colorectal cancer and the relationship is more significant in men than in women among different cancer subsites. Indexes of abdominal obesity are more sensitive than those of overall obesity.