Seizure Induced by a Therapeutic Dose of Venlafaxine ER: A Case Report.

Venlafaxine is a selective serotonin and norepinephrine reuptake inhibitor commonly used for the treatment of depression. Although listed as an adverse reaction, seizure activity associated with a therapeutic dose of venlafaxine has rarely been documented. A review of the literature reveals only 2 cases of venlafaxine-induced seizures, both of which were generalized tonic-clonic seizures in patients on doses at the higher end of the therapeutic range. We report the case of a 44-year-old woman undergoing antituberculosis therapy who suffered complex partial seizures after ingestion of a low therapeutic dose of venlafaxine extended release (ER). Her first seizure was observed soon after venlafaxine ER was titrated from 37.5 to 75 mg daily, with a total of 9 witnessed complex partial seizures. After titrating the dose of the venlafaxine ER back down to 37.5 mg daily and beginning lamotrigine anticonvulsant therapy, the patient exhibited no further seizures. The development of seizure activity under therapeutic dosing of venlafaxine should be brought to the attention of the health care prescriber. The potential for drug-drug interactions involving venlafazine, particularly in combination with multiple drugs, such as isoniazid and levofloxacin, needs to be recognized.

Two SNAP-25 genetic variants in the binding site of multiple microRNAs and susceptibility of ADHD: A meta-analysis.

The aim of this meta-analysis is to assess the associations between two most widely investigated polymorphisms (rs3746544 and rs1051312) in the 3'UTR of the SNAP-25 gene and susceptibility of ADHD. Two investigators selected related studies and assessed methodological quality independently. Six studies were included in this meta-analysis for a total of 715 cases and 655 controls. There is no apparent association between rs3746544 polymorphisms and risk of ADHD. However, subgroup analysis based on ethnicity demonstrated a strong association between rs3746544 polymorphism and ADHD in the subset of Asian participants, but not among Caucasians. Compared to the T allele, the allele G was associated with a significantly decreased risk of developing ADHD in the Asian population (odds ratio (OR) = 0.70, 95% confidence interval (CI) = 0.52-0.95, p = 0.02). The association between the TT genotype and ADHD risk was also significantly increased as compared to G/T (OR = 1.56, 95% CI = 1.00-2.44, p = 0.05) and the dominant genetic model (GG + GT vs. TT: OR = 1.51, 95% CI = 1.07-2.13, p = 0.02). For the rs1051312 SNP, being homozygous for the minor allele (C/C) was associated with a 3.66 higher odds of ADHD as compared to cases homozygous for the major allele (T/T) (95% CI = 1.64-8.13, p = 0.001), and 3.57 higher odds as compared to heterozygous (C/T) carriers (95% CI = 2.01-12.90, p < 0.001). Our results suggest that the polymorphisms rs3746544 and rs1051312 may increase the odds of developing ADHD. Additional studies are needed to confirm these findings.

Evaluation of potential regulatory function of breast cancer risk locus at 6q25.1.

In a genome-wide association study conducted among Chinese women, we identified the single nucleotide polymorphism (SNP) rs2046210 at 6q25.1 for breast cancer risk. To explore a potential regulatory role for this risk locus, we measured expression levels of nine genes at the locus in breast cancer tissue and adjacent normal tissue samples obtained from 67 patients recruited in the Shanghai Breast Cancer Study. We found that rs2046210 had a statistically significant association with the expression levels of the AKAP12 and ESR1 genes in adjacent normal breast tissues. Women who carry the AA/AG risk genotypes had higher expressions of these two genes compared to those who carry G/G genotypes (P = 0.02 and 0.04 for the AKAP12 and ESR1, respectively). However, no significant differences of SNP rs2046210 with gene expression levels were found in tumor tissues. In The Cancer Genome Atlas samples, the AA/AG risk genotypes of SNP rs2046210 were associated with a significantly higher expression level of the AKAP12 gene and a lower level of the ESR1 gene in tumor tissue. Functional analysis using ENCODE data revealed that SNP rs7763637, which is in strong linkage disequilibrium with SNP rs2046210, is likely a potential functional variant, regulating the AKAP12 gene. Taken together, these results from our study suggest that the association between the 6q25.1 locus and breast cancer risk may be mediated through SNPs that regulate expressions of the AKAP12 gene.

Evaluation of functional genetic variants for breast cancer risk: results from the Shanghai breast cancer study.

In previous studies among 1,144 cases and 1,256 controls recruited in stage 1 of the Shanghai Breast Cancer Study (SBCS I; 1996-1998), 18 known or potentially functional single nucleotide polymorphisms (SNPs) in 16 genes were found to be associated with breast cancer risk. The authors evaluated these associations among 1,918 cases and 1,819 controls recruited in stage 2 of the SBCS (SBCS II; 2002-2005) using genetic effect models and subgroup analyses predetermined from SBCS I results. Five SNPs (AHR rs2066853, ATM rs1003623, ESR1 rs2234693, GSTP1 rs1695, and SHBG rs6259) showed generally consistent results in SBCS I and SBCS II and statistically significant associations with breast cancer risk in combined analyses, mostly in subgroups defined by age or menopausal status. Further, the relation between breast cancer risk and SHBG rs6259 was found to vary by body mass index (weight (kg)/height (m)(2)) (P for interaction = 0.003). The strongest reduction in risk associated with SHBG rs6259 was found for lean (body mass index <23) postmenopausal minor allele carriers (odds ratio = 0.6, 95% confidence interval: 0.5, 0.8; P = 4.6 × 10(-4)). This biologically plausible and highly significant finding provides strong evidence for a true association among Asian women. This study also highlights the value of gene-environment interaction analyses in evaluating genetic factors for complex diseases.

No evidence for association of the MDM2-309 T/G promoter polymorphism with prostate cancer outcomes.

OBJECTIVES: Mouse double-minute 2 (MDM2) SNP309 polymorphism (T>G) has been correlated with an increased risk of cancer in multiple tumor types. MDM2 overexpression has shown to be weakly associated with distant tumor metastases, and down-regulation of MDM2 via antisense oligonucleotides in vitro has resulted in the radiosensitization of prostate cancer cell lines. Based on these results, we decided to evaluate the role of MDM2 SNP309 in the context of histopathologic parameters and clinical outcomes in prostate cancer tumors. MATERIALS AND METHODS: The population consisted of 212 consecutive prostate cancer patients who underwent radical prostatectomy between 1997 and 1999 at Vanderbilt University Medical Center. Two hundred eight of the samples were successfully genotyped for the MDM2 SNP309 polymorphism. Correlations between the polymorphism, recurrence, and survival data were analyzed using univariate and multivariate genetic models. RESULTS: The only prognostic factor predictive of overall survival in our study was Gleason score (P<0.005). Using χ(2) analysis, we determined that the MDM2 SNP309 polymorphism had no significant association with race (P=0.7512), patient's age at diagnosis (P=0.6820), pre-prostatectomy PSA level (P=0.8606), Gleason's score (P=0.4839), surgical margin status (P=1.0000), extracapsular extension (P=0 .6175), and disease stage (P=0.4945). In addition, there was no significant difference in 3-year recurrence-free survival (P=0.218), or 8-year overall survival (P=0.376). CONCLUSIONS: Our study finds no evidence for association of the MDM2 SNP309 polymorphism with clinicopathologic variables, recurrence risk, and overall survival outcome in prostate cancer.

Quantitative assessment of AKAP12 promoter methylation in colorectal cancer using methylation-sensitive high resolution melting: Correlation with Duke's stage.

BACKGROUND: The expression of AKAP12 (A Kinase anchoring protein 12) is markedly reduced in a variety of cancers. The purpose of this study was to establish a methylation-sensitive high resolution melting (MS-HRM) assay for the quantitative detection of AKAP12 promoter methylation and expression and the association with clinicopathological variables in human colorectal cancer. We also assessed the effect of AKAP12 re-expression on cell growth and colony formation. RESULTS: Downregulation or loss of AKAP12 mRNA expression was detected in 31 of 45 tissue samples (68.9%). No significant correlation was observed between the reduced expression levels and patient age, gender, Duke's stage or tumor differentiation. Methylation (>1%) of the AKAP12 promoter region was present in 35 of 45 (77.8%) carcinoma tissue samples and 6 of 45 (13.3%) adjacent tissue samples. AKAP12 methylation was significantly higher in the colorectal cancer tissues exhibiting advanced Duke's stages. Treatment of the three colorectal carcinoma cell lines (LoVo, COLO320 and SW480) with completely methylated AKAP12 with inhibitors of DNA methyltransferase (5-Aza-2'-deoxycytidine) markedly increased expression of AKAP12 and decreased methylation levels. Ectopic expression of AKAP12 in the LoVo cell line suppressed cell growth and inhibited colony formation. METHODS: The AKAP12 gene was examined by quantitative RT-PCR, MS-HRM analysis and bisulfite sequencing in 45 paired tissue samples obtained from primary colorectal carcinomas and the corresponding adjacent tissues. In addition, five colorectal carcinoma cell lines (LoVo, COLO205, SW480, LS174T and COLO320) were investigated and western blot analysis was used to investigate changes in protein expression. A proliferation assay and soft agar assay were performed after overexpression of AKAP12. CONCLUSION: Our study demonstrated that MS-HRM is a robust, fast and sensitive method for AKAP12 methylation analysis. AKAP12 methylation represents a potential molecular biomarker for predicting the malignancy of this cancer.

Two-stage case-control study of DNMT-1 and DNMT-3B gene variants and breast cancer risk.

Aberrant DNA methylation of CpG islands is a common epigenetic alteration found in cancers. DNA methylation is typically mediated by DNA methyltransferases (DNMTs). Only two studies have evaluated DNMT-1 and/or DNMT-3B gene polymorphisms in relation to breast cancer risk, and results have been inconsistent. We comprehensively evaluated genetic variations in the DNMT-1 and DNMT-3B genes with breast cancer risk among the participants of the Shanghai Breast Cancer Study, a large-scale, two-stage, case-control study. Of the 25 SNPs in the DNMT-1 and DNMT-3B genes analyzed, only one (rs8101866) reached a normal significance level (P = 0.042). This association, however, was no longer statistically significant after adjustment for multiple comparisons. Our data suggest that there is no apparent association of common DNMT-1 and DNMT-3B polymorphisms with the risk of breast cancer among Chinese women.

Mutations in the mitochondrial DNA D-loop region and breast cancer risk.

Mitochondrial genome alterations have been suggested to play an important role in carcinogenesis. The D-loop region of mitochondrial DNA (mtDNA) contains essential transcription and replication elements, and mutations in this region may serve as a potential sensor for cellular DNA damage and a marker for cancer development. Using data and samples from the Shanghai Breast Cancer Study, we investigated MnlI restriction sites located between nucleotides 16,106 and 16,437 of the mtDNA D-loop region to evaluate restriction fragment length polymorphism (RFLP) patterns in tumor tissue from 501 primary breast cancer patients when compared with tumor tissue from 203 women with benign breast disease (BBD). RFLP patterns in correspondingly paired, adjacent, non-tumor tissues taken from 120 primary breast cancer patients and 59 BBD controls were also evaluated. Five common RFLP patterns were observed, and no significant differences were observed in the distribution of these patterns between tumor and adjacent non-tumor tissue samples from breast cancer patients and tissue samples from BBD controls. On the other hand, somatic MnlI site mutations, defined as a difference in MnlI RFLP pattern between tumor tissue and the corresponding, adjacent, non-tumor tissue, occurred more frequently in breast cancer patients (28.3%) than in BBD patients (15.3%) (P = 0.05) and more frequently in proliferative BBD (13.0%) than in non-proliferative BBD (7.1%). Our data suggest that somatic MnlI site mutations may play a role in the pathogenesis of breast cancer.

Aberrant methylation of EphA7 in human prostate cancer and its relation to clinicopathologic features.

EphA7 is a member of Eph/ephrins family and play diverse roles in carcinogenesis. The aim of our study was to investigate functional and structural alterations of EphA7 in prostate cancer and determine if those findings correlate with the clinicopathologic features of prostate cancer. Forty-eight prostate carcinomas, 31 benign prostate hyperplasias, 5 normal prostate tissues and 3 prostate cell lines (LNCaP, DU145 and PC-3) were examined with quantitative RT-PCR, methylation-specific PCR and immunohistochemistry. Downregulation or loss of EphA7 mRNA expression was detected in 23 of 48 (47.9%) prostate carcinomas, and 2 of 31 (6.5%) hyperplasias. Methylation of the EphA7 promoter region was present in 20 of 48 (41.7%) of carcinomas and 6 of 31 (19.3%) hyperplasias, respectively. Immunostaining analysis showed EphA7 protein was absent in 10 of 30 (33.3%) carcinoma samples available and 8 of them (80.0%) exhibited hypermethylation. The frequency of EphA7 methylation was higher in cancer patients with higher Gleason score. Treatment of DU145 cells harboring methylation with 5-aza-2'-deoxycytidine reactivated expression of EphA7. Ectopic expression of EphA7 in DU145 cells did not suppress cell growth but inhibited colony formation. Our study provides evidence that epigenetic inactivation of EphA7 may be involved in prostate carcinogenesis.

Minimally invasive thoracoscope-assisted Heller myotomy for achalasia.

Forty-five patients (20 men and 25 women) with a median age of 46.5 years, who were diagnosed with esophageal achalasia by clinical history, esophagoscopy, and barium esophagogram, underwent thoracoscope-assisted Heller myotomy with a minimal incision. Esophageal pressure and pH were monitored. Two patients were excluded because of mucosal perforation during the operation, requiring conversion to an open procedure. There was no postoperative esophageal leakage or hospital death. All patients resumed a normal diet as soon as gastrointestinal function recovered, and their symptoms disappeared completely. The mean operative time was 1.2 hours (range, 0.5-3.8 hours). After 2.1 years of follow-up, the outcome was rated excellent in 33 (77%) patients, good in 7 (16%), and fair in 3 (7%). Esophageal dilation was required in 3 patients because of relapsing dysphagia within 3 months after the operation. Four (9%) patients had some regurgitation but no further surgical or medical treatment was needed. Esophageal pressure and pH correlated with the clinical manifestations. Our modified Heller myotomy with the assistance of thoracoscopy is effective for achalasia.

Association of mitochondrial DNA displacement loop (CA)n dinucleotide repeat polymorphism with breast cancer risk and survival among Chinese women.

Mitochondrial genome alternations may be involved in carcinogenesis. The noncoding region of the mitochondrial DNA (mtDNA) displacement loop (D-loop) has emerged as a mutational hotspot. Using data from a population-based case-control study conducted among Chinese women in Shanghai, we evaluated associations of breast cancer risk and survival with the mtDNA D-loop (CA)(n) dinucleotide repeat polymorphism. Included in the study were 1,058 cases and 1,129 age frequency-matched community controls that participated in the Shanghai Breast Cancer Study between 1996 and 1998. Breast cancer patients were followed to determine intervals of overall survival and disease-free survival. Overall, there was no association between the mtDNA D-loop (CA)(n) repeat polymorphism and breast cancer risk. Patients with multiple alleles of the mtDNA D-loop (CA)(n) polymorphism (heteroplasmy) had significantly poorer disease-free survival than those with one allele of the mtDNA D-loop (CA)(n) polymorphism (hazard ratio 1.62; 95% confidence interval, 1.16-2.26). These results suggest that the mtDNA D-loop (CA)(n) repeat polymorphism may be associated with breast cancer survival. Additional studies with a larger sample size are warranted.

Quantitative analysis of mitochondrial DNA 4977-bp deletion in sporadic breast cancer and benign breast diseases.

The mitochondrial DNA (mtDNA) 4977-bp deletion (DeltamtDNA(4977) mutation) is one of the most frequently observed mtDNA mutations in human tissues and may play a role in carcinogenesis. Only a few studies have evaluated DeltamtDNA(4977) mutation in breast cancer tissue, and the findings have been inconsistent, which may be due to methodological differences. In this study, we developed a quantitative real-time PCR assay to assess the level of the DeltamtDNA(4977) mutation in tumor tissue samples from 55 primary breast cancer patients and 21 patients with benign breast disease (BBD). The DeltamtDNA(4977) mutation was detected in all of the samples with levels varying from 0.000149% to 7.0%. The DeltamtDNA(4977) mutation levels were lower in tumor tissues than in adjacent normal tissues in both breast cancer and BBD subjects. The differences, however, were not statistically significant. No significant difference between breast cancer and BBD patients was found in the DeltamtDNA(4977) mutation levels of tumor tissues and adjacent normal tissues. The DeltamtDNA(4977) mutation levels were not significantly associated with clinicopathological characteristics (age, histology, tumor stage, and ER/PR status) in breast cancer or BBD patients. These results do not support the notion that the mitochondrial DNA 4977-bp deletion plays a major role in breast carcinogenesis.

Expression of cytochrome P450 1B1 and catechol-O-methyltransferase in breast tissue and their associations with breast cancer risk.

Cytochrome P450 1B1 (CYP1B1) and catechol-O-methyltransferase (COMT) are important estrogen-metabolizing enzymes that may affect breast cancer risk. Few studies have directly measured the expression of CYP1B1 and COMT genes in breast tissue samples. The subjects in this study were a subgroup of participants of the Shanghai Breast Cancer Study including 64 patients diagnosed with breast cancer and 68 patients diagnosed with benign breast diseases (BBD) who provided samples of tumor tissue and adjacent nontumor tissue to the study. We compared CYP1B1 and COMT mRNA expression in tumor tissue and adjacent nontumor tissue in both breast cancer patients and BBD patients. High levels of CYP1B1 expression and low levels of COMT expression in adjacent nontumor tissue were associated with a significantly increased breast cancer risk in a nonlinear manner. Odds ratios and 95% confidence intervals (in parentheses) for the midpoints of the first, second, fourth, and fifth quintiles of gene expression levels compared with the overall median levels in BBD subjects were 0.21 (0.07-0.67), 0.81 (0.69-0.95), 1.20 (1.05-1.38), and 1.55 (1.12-2.15) for CYP1B1 and 1.72 (1.17-2.55), 1.19 (1.05-1.35), 0.83 (0.73-0.95), and 0.78 (0.65-0.93) for COMT, respectively. These results support the hypothesis that the formation and accumulation of catechol estrogens in breast tissue through increased CYP1B1 expression and reduced COMT expression may play a significant role in breast cancer risk.

Two-stage case-control study of common ATM gene variants in relation to breast cancer risk.

The ataxia telangiectasia mutated (ATM) gene is a tumor suppressor gene that plays a critical role in cell cycle arrest, apoptosis, and DNA repair. We evaluated two reported nonsynonymous SNPs (rs1800054 and rs1800058) and three additional common gene variants (rs664143, rs228589, rs1003623) in the ATM gene in relation to breast cancer risk. A two-stage case-control study, using data from the Shanghai Breast Cancer Study, was conducted in which all SNPs were screened in the stage I study, including 1,123 cases and 1,232 controls. Any promising associations were re-evaluated in the stage II study, including 2,003 cases and 1,918 controls. In the stage I study, with the exception of rs1003623, no apparent association was found for any other SNPs with breast cancer risk. For the rs1003623, the T allele was associated with an increased breast cancer risk among postmenopausal women with odds ratios (ORs) of 1.4 (95% Confidence Intervals (CIs) = 1.0-1.9) for the CT and 1.6 (95% CIs = 1.0-2.4) for the TT, (P for trend = 0.03). This association, however, was not replicated in the stage II study, suggesting that the positive association identified in stage I for rs1003623 may be due to chance. Our study reveals no apparent association of common ATM variants with breast cancer risk and underscores the importance of replication using independent samples to reduce type I errors in association studies of low-penetrance genetic factors.

Expression patterns of the ATM gene in mammary tissues and their associations with breast cancer survival.

BACKGROUND: The ataxia-telangiectasia mutated (ATM) gene plays a critical role in cell-cycle arrest, apoptosis, and DNA repair. However, to date, no study has directly investigated the association between ATM gene expression and breast cancer survival. METHODS: ATM gene expression levels were evaluated in tumor and adjacent normal tissue from patients diagnosed with primary breast cancer or BBD using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) assays. Cox regression models were used to evaluate the association of ATM gene expression and survival in a cohort of 471 breast cancer patients. RESULTS: In breast cancer cases, ATM expression in cancer tissues was decreased by approximately 50% compared with adjacent normal tissues from the same patients. In BBD cases, the expression level of the ATM gene was similar in benign tumor tissue and adjacent normal tissues. No apparent difference was found in ATM gene expression levels in adjacent normal tissues obtained from cancer patients or BBD controls. Compared with patients with the lowest tertile of the ATM mRNA, patients in the upper 2 tertiles had more favorable disease-free survival (hazard ratio [HR]=0.46, 95% confidence interval [CI]: 0.30-0.73 and HR=0.52, 95% CI: 0.33-0.81, respectively) and overall survival (HR=0.56, 95% CI: 0.35-0.92 and HR=0.70, 95% CI: 0.43-1.13, respectively). CONCLUSIONS: The ATM gene expression was down-regulated in breast cancer tissues and a high ATM gene expression level in breast cancer tissue was associated with a favorable prognosis.

Promoter methylation status of the MGMT, hMLH1, and CDKN2A/p16 genes in non-neoplastic mucosa of patients with and without colorectal adenomas.

The aberrant methylation of CpG islands is a common epigenetic alteration found in cancers. The process contributes to cancer formation through the transcriptional silencing of tumor suppressor genes. CpG island methylation has been observed in aberrant crypt foci (ACF) and adenomas in the colon, implicating it in the earliest aspects of colon cancer formation. In addition, some investigators have identified an age-related increase in DNA methylation of the ESR1 locus in the colon mucosa, suggesting that DNA methylation may be a pre-neoplastic change that increases the risk of colon adenomas and colon cancer. We investigated the methylation status in the promoter regions of the CDKN2A/p16, hMLH1, and MGMT genes in human non-neoplastic rectal mucosa and evaluated whether these methylation markers may predict the presence of adenomatous polyps in the colon. The promoter methylation patterns of these genes were examined in rectal biopsies (mucosa samples) of 97 colorectal adenoma cases and 94 healthy controls using methylation-specific PCR (MSP) assays. Methylation of the MGMT and hMLH1 genes was present in both cases and controls, with a frequency of 12.4% and 18.1% for the MGMT gene and 12.4% and 11.7% for the hMLH1 gene. The frequency of CDKN2A/p16 promoter methylation was very rare in normal colorectal tissue with a frequency of approximately 2%. Overall, no apparent case-control difference was identified in the methylation status of these genes, either alone or in combination. hMLH1 methylation was more frequently observed among overweight or obese subjects (BMI>/=25) with an adjusted OR of 3.7 (95% CI=1.0-13.7). Methylated alleles of the hMLH1 and MGMT genes were frequently detected in normal rectal mucosa, while the frequency of CDKN2A/p16 methylation detected was very low. The methylation status of these genes in rectal mucosa biopsies detected by MSP assays may not distinguish between patients with and without adenomas in the colon.

The rat model of type 2 diabetic mellitus and its glycometabolism characters.

To develop a rat model of type 2 diabetic mellitus that simulated the common manifestation of the metabolic abnormalities and resembled the natural history of a certain type 2 diabetes in human population, male Sprague-Dawley rats (4 months old) were injected with low-dose (15 mg/kg) STZ after high fat diet (30% of calories as fat) for two months (L-STZ/2HF). The functional and histochemical changes in the pancreatic islets were examined. Insulin-glucose tolerance test, islet immunohistochemistry and other corresponding tests were performed and the data in L-STZ/2HF group were compared with that of other groups, such as the model of type 1 diabetes (given 50 mg/kg STZ) and the model of obesity (high fat diet). The body weight of rats in the group of rats given 15 mg/kg STZ after high fat diet for two months increased significantly more than that of rats in the group of rats given 50 mg/kg STZ (the model of type 1 diabetes) (595 +/- 33 g vs. 352 +/- 32 g, p<0.05). Fast blood glucose levels for L-STZ/2HF group were 16.92 +/- 1.68 mmol/l, versus 5.17 +/- 0.55 mmol/l in normal control and 5.59 +/- 0.61 mmol/l in rats given high fat diet only. Corresponding values for fast serum insulin were 0.66 +/- 0.15 ng/ml, 0.52 +/- 0.13 ng/ml, 0.29 +/- 0.11 ng/ml, respectively. Rats of type 2 diabetes (L-STZ/2HF) had elevated levels of triglyceride (TG, 3.82 +/- 0.88 mmol/l), and cholesterol(Ch, 2.38 +/- 0.55 mmol/l) compared with control (0.95 +/- 0.15 mmol/l and 1.31 +/- 0.3 mmol/l, respectively) (p<0.05). The islet morphology as examined by immunocytochemistry using insulin antibodies in the L-STZ/2HF group was affected and quantitative analysis showed the islet insulin content was higher than that of rats with type 1 diabetes (P<0.05). We concluded that the new rat model of type 2 diabetes established with conjunctive treatment of low dose of STZ and high fat diet was characterized by hyperglycemia and light impaired insulin secretion function accompanied by insulin resistance, which resembles the clinical manifestation of type 2 diabetes. Such a model, easily attainable and inexpensive, would help further elucidation of the underlying mechanisms of diabetes and its complications.

Nitric oxide synthase expression in human bladder cancer and its relation to angiogenesis.

Nitric oxide (NO) is synthesized by the enzyme family of nitric oxide synthases (NOS) and plays an important role in tumor growth and angiogenesis. The expression of two of the NOS isoforms, the endothelial and inducible isoforms (eNOS and iNOS, respectively), were evaluated in bladder tissue from patients with transitional cell carcinoma (TCC). The specimens were procured from 58 patients with TCC and 14 cases of normal bladder mucosa were used as a control group. NOS immunohistochemistry was performed and microvessal density (MVD) was determined. iNOS specific proteins were found in 47 of 58 bladder cancer specimens but not in control bladder tissue. The endothelial cells in both normal urothelium and tumor tissue showed a highly positive eNOS immunostaining. The MVD was 39.3+/-19.5 and 29.3+/-10.5 in TCC positive and negative for iNOS, respectively ( P<0.01). A correlation between iNOS immunoreactivity and tumor grade in bladder carcinoma could not be verified. These results indicate that NO generation from iNOS in the malignant epithelium and from eNOS in tumor stroma play a important role in tumor angiogenesis.

Production of extracellular domain of human tissue factor using maltose-binding protein fusion system.

Making use of the physiological process of coagulation as an anti-tumor effector function may be beneficial in various coagulation-mediated diseases. Preclinical and clinical studies with novel tissue factor targeting constructs require that efficient procedures for preparing large quantities of pure truncated TF (tTF) become available. In this study, we described a simple and rapid on-column method for purifying large quantities of human tTF from Escherichia coli. The coding region of extracellular domain of tissue factor was linked to the 3(')-end of maltose-binding protein (MBP) gene. The fusion protein was expressed as soluble form after induction by isopropylthio-beta-D-galactoside (IPTG). MBP-tTF was purified by amylose affinity chromatography. MBP can be removed by digestion with factor Xa. Expression could represent 21.5% of the total soluble protein in E. coli, allowing approximately 15mg of highly purified protein to be obtained per liter of bacterial culture. The fusion protein was recognized in Western blot by anti-TF monoclonal antibody and the activity was confirmed by chromogenic assay. This MBP-fusion system permits large-scale functional expression and purification of recombinant soluble proteins, providing a basis for the future study of structure and function of tTF.

[Gene expression pattern of senescence associated genes in rat muscle].

This work is aimed at the investigation of the senescence associated genes differentially expressed in rat muscle by cDNA microarray. After total RNA isolation, mRNA purification and probe preparation, the gene expression patterns of rat muscle from the old group (30 months old) and the young group (3 months old) were compared by cDNA gene chips. In the muscle of old rats there were reproducibly 127 differentially expressed genes, among which some down-regulated genes were involved in energy metabolism and signal transduction, while some up-regulated genes were related to protein degradation and cell apoptosis. Meanwhile muscle fiber atrophy with mitochondria vacuolation was found in aging rat by electron microscope.