The role of spironolactone in the metabolism of serum type I collagen in elderly patients with atrial fibrillation

OBJECTIVE

This study aimed to explore the possible mechanism of spironolactone in reduction of atrial fibrosis in elderly patients with atrial fibrillation.

PATIENTS AND METHODS

67 patients with atrial fibrillation and 30 matching patients with sinus rhythm were included into this study, in which the former patients were randomly divided into the conventional treatment group (33 cases) and spironolactone (20 mg/d) treatment group (34 cases). They underwent follow-ups for 6 months. The levels of serum aldosterone, PICP (propeptide of type I procollagen) and CITP (carboxy-terminal cross-linking telopeptide of type I collagen) were determined before and after treatment.

RESULTS

The concentrations of serum PICP, CITP and aldosterone and left atrial size in the atrial fibrillation group were all higher than the control group (t values were 7.982, 5.950, 9.309, 9.050, respectively, p < 0.01), with a significant statistical difference. The concentrations of serum PICP and aldosterone were both positively corelated to the left atrial size in the atrial fibrillation group (r values were 0.302 and 0.369, respectively). The levels of serum aldosterone and PICP after treatment were both decreased compared to those before treatment in the spironolactone treatment group and conventional treatment group, especially in the spironolactone treatment group. There were statistical differences in the levels of serum aldosterone and PICP after treatment between the two groups (t values were 2.872 and 3.054, respectively, p < 0.01).

CONCLUSIONS

Spironolactone could reduce the levels of serum aldosterone and PICP in patients with atrial fibrillation, so as to reduce the atrial fibrosis and delay the occurrence and development of atrial fibrillation.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies

BACKGROUND

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients.

PATIENTS AND METHODS

Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS).

RESULTS

Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82).

CONCLUSION

Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches.

TRIAL REGISTRATION

NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Designing of the massive gas injection valve for the joint Texas experimental tokamak

In order to mitigate the negative effects of the plasma disruption a massive gas injection (MGI) valve is designed for the joint Texas experimental tokamak. The MGI valve is based on the eddy-current repulsion mechanism. It has a fueling volume of 30 ml. The piston of the MGI valve is made by non-ferromagnetic material, so it can be installed close to the vacuum vessel which has a strong toroidal magnetic field. A diode is use to prevent current oscillation in the discharge circuit. The drive coil of the valve is installed outside the gas chamber. The opening characteristics and the gas flow of the MGI valve have been tested by a 60 l vacuum chamber. Owing to the large electromagnetic force the reaction time of the valve is shorter than 0.3 ms. Duration for the opening of the MGI valve is in the order of 10 ms.

Matrine reduces yeast-to-hypha transition and resistance of a fluconazole-resistant strain of Candida albicans

AIMS

To evaluate the potential effect of matrine on reducing the growth of hypha and lowering the resistance of a fluconazole-resistant colony of Candida albicans.

METHODS AND RESULTS

Candida albicans SC5314 and a fluconazole-resistant C. albicans 215 were used. As for C. albicans SC5314, minimal inhibitory concentration (MIC(80)) and effective concentration (EC(50)) were determined, 1 mg ml(-1) matrine could inhibit nearly 80% of planktonic growth by inverted microscope, 2 mg ml(-1) matrine suppressed 50% of metabolic activity of biofilm by XTT assay, vanishing hypha could be observed on spider agar containing 2 mg ml(-1) matrine, the expressions of three hypha-related genes, namely ALS 3, SUN 41 and PBS 2, were suppressed by 29, 45 and 61% by 2 mg ml(-1) matrine. Also, matrine could lower the resistance of C. albicans 215, in either the free-floating form or the biofilm phenotype.

CONCLUSIONS

Matrine had favourable antifungal potential and might be able to reverse the fluconazole resistance of clinical isolates at relatively high concentration. The anti-candidal performance of matrine could be tightly associated with yeast-to-hypha transition proved by spider agar test and qRT-PCR.

SIGNIFICANCE AND IMPACT OF STUDY

More efforts are needed to find new antifungal agents. Matrine could be a potential candidate to fight against Candida-related infections by regulating yeast-to-hypha transition.

The DNA double-strand break response is abnormal in myeloblasts from patients with therapy-related acute myeloid leukemia

The complex chromosomal aberrations found in therapy-related acute myeloid leukemia (t-AML) suggest that the DNA double-strand break (DSB) response may be altered. In this study we examined the DNA DSB response of primary bone marrow cells from t-AML patients and performed next-generation sequencing of 37 canonical homologous recombination (HR) and non-homologous end-joining (NHEJ) DNA repair genes, and a subset of DNA damage response genes using tumor and paired normal DNA obtained from t-AML patients. Our results suggest that the majority of t-AML patients (11 of 15) have tumor-cell intrinsic, functional dysregulation of their DSB response. Distinct patterns of abnormal DNA damage response in myeloblasts correlated with acquired genetic alterations in TP53 and the presence of inferred chromothripsis. Furthermore, the presence of trisomy 8 in tumor cells was associated with persistently elevated levels of DSBs. Although tumor-acquired point mutations or small indels in canonical HR and NHEJ genes do not appear to be a dominant means by which t-AML leukemogenesis occurs, our functional studies suggest that an abnormal response to DNA damage is a common finding in t-AML.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

RANKL promotes the growth of decidual stromal cells in an autocrine manner via CCL2/CCR2 interaction in human early pregnancy

OBJECTIVE

Receptor-activator of NF-κB ligand (TNFSF11, also known as RANKL) and its receptor RANK are essential regulators on bone remodeling, mammary gland development and hormone-associated breast cancer development. However, the expression pattern and role of RANKL/RANK axis in decidual stromal cells (DSCs) are unclear in human early pregnancy.

STUDY DESIGN

We analyzed RANKL/RANK expression in DSCs by real-time PCR, immunhistochemistry, enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. Then BrdU cell proliferation assay, flow cytometry assay and ELISA were performed to investigate the effect of recombinant human RANKL and DSCs-derived RANKL on the proliferation, apoptosis, chemokine (C-C motif) ligand 2 (CCL2) secretion, C-C chemokine receptor type 2 (CCR2) and other target proteins expression in DSCs in vitro, respectively.

RESULTS

Here we show that DSCs co-express RANKL/RANK. Not only recombinant human (rh) RANKL but also the DSC-secreted RANKL stimulate proliferation and anti-apoptosis, and elevate CCL2 secretion and CCR2 expression of DSCs. Furthermore, the stimulatory effects on the proliferation, anti-apoptosis and the expression of Bcl-2 and Ki67 and inhibitory signaling on Fas ligand (FasL) in DSCs induced by RANKL can be partly reversed by the way of blocking CCL2 and or CCR2.

CONCLUSIONS

Our results have revealed that RANKL/RANK signal promotes Bcl-2 and Ki67 and decreases FasL expression, and further as a positive regulator for stimulating the proliferation and growth of DSCs through up-regulating CCL2/CCR2 signal, which finally contributes to the establishment and maintenance of physiological pregnancy.

Clonal diversity of recurrently mutated genes in myelodysplastic syndromes

Recent studies suggest that most cases of myelodysplastic syndrome (MDS) are clonally heterogeneous, with a founding clone and multiple subclones. It is not known whether specific gene mutations typically occur in founding clones or subclones. We screened a panel of 94 candidate genes in a cohort of 157 patients with MDS or secondary acute myeloid leukemia (sAML). This included 150 cases with samples obtained at MDS diagnosis and 15 cases with samples obtained at sAML transformation (8 were also analyzed at the MDS stage). We performed whole-genome sequencing (WGS) to define the clonal architecture in eight sAML genomes and identified the range of variant allele frequencies (VAFs) for founding clone mutations. At least one mutation or cytogenetic abnormality was detected in 83% of the 150 MDS patients and 17 genes were significantly mutated (false discovery rate ≤0.05). Individual genes and patient samples displayed a wide range of VAFs for recurrently mutated genes, indicating that no single gene is exclusively mutated in the founding clone. The VAFs of recurrently mutated genes did not fully recapitulate the clonal architecture defined by WGS, suggesting that comprehensive sequencing may be required to accurately assess the clonal status of recurrently mutated genes in MDS.

Systematic analysis of human lysine acetylation proteins and accurate prediction of human lysine acetylation through bi-relative adapted binomial score Bayes feature representation

Lysine acetylation is a reversible post-translational modification (PTM) which has been linked to many biological and pathological implications. Hence, localization of lysine acetylation is essential for deciphering the mechanism of such implications. Whereas many acetylated lysines in human proteins have been localized through experimental approaches in wet lab, it still fails to reach completion. In the present study, we proposed a novel feature extraction approach, bi-relative adapted binomial score Bayes (BRABSB), combined with support vector machines (SVMs) to construct a human-specific lysine acetylation predictor, which yields, on average, a sensitivity of 83.91%, a specificity of 87.25% and an accuracy of 85.58%, in the case of 5-fold cross validation experiments. Results obtained through the validation on independent data sets show that the proposed approach here outperforms other existing lysine acetylation predictors. Furthermore, due to the fact that global analysis of human lysine acetylproteins, which would ultimately facilitate the systematic investigation of the biological and pathological consequences associated with lysine acetylation events, remains to be resolved, we made an attempt to systematically analyze human lysine acetylproteins, demonstrating their diversity with respect to subcellular localization as well as biological process and predominance by "binding" in terms of molecular function. Our analysis also revealed that human lysine acetylproteins are significantly enriched in neurodegenerative disorders and cancer pathways. Remarkably, lysine acetylproteins in mitochondria are significantly related to neurodegenerative disorders and those in the nucleus are instead significantly involved in pathways in cancers, all of which might ultimately provide novel global insights into such pathological processes for the therapeutic purpose. The web server is deployed at http://www.bioinfo.bio.cuhk.edu.hk/bpbphka.

Gestational hypertension risk evaluation based on epidemiological, biochemical, and hemodynamic factors

PURPOSE

Gestational hypertension (GH) is a serious health hazard for pregnant women and fetuses. The incidence of GH involves many epidemiological, biochemical, and hemodynamic factors.

METHODS

The current study investigated the GH risk under the influence of epidemiological, biochemical, and hemodynamic factors, and designed corresponding GH risk evaluation methods and apparatus.

RESULTS

The evaluation method has 74.15% sensitivity and 81.84% specificity. The ROC area under the curve is 0.841. The apparatus automatically imports epidemiological, biochemical, and hemodynamic factors, and then expresses the GH risk as numbers, bar codes, and colors through logic array analysis.

CONCLUSION

The GH risk value can effectively give the risk level of GH. The GH risk barcode can improve the degree of automation of information storage, transmission, and identification in GH monitoring. The GH risk color can also improve the GH macro description.

Association of leptin receptor gene polymorphisms and essential hypertension in a Chinese population

BACKGROUND

The leptin receptor (LEPR) is an important regulator of leptin activity and resistance. Several single nucleotide polymorphisms (SNP) of LEPR have been linked to diseases accompanying obesity and/or obesity-related diseases in different populations. However, the results from published studies remain inconsistent rather than conclusive.

AIM

To investigate whether LEPR SNP are associated with essential hypertension and related metabolic traits in Chinese subjects.

MATERIALS AND METHODS

A total of 544 Chinese patients with hypertension and 357 non-hypertensive subjects were screened. The genotypes of LEPR polymorphisms were determined by PCR-restriction fragment length polymorphism methods. Demographic and biochemical characteristics including waist circumference, waist-to-hip ratio, body mass index (BMI), lipids profiles, glucose metabolism, and leptin levels were obtained for analysis.

RESULTS

This case-control study showed associations between the frequencies of AA genotype and A allele of Gln223Arg and hypertension (p=0.029, p=0.002, respectively). Furthermore, the Gln223Arg polymorphism was significantly associated with plasma leptin levels (p<0.001), while no correlations between Lys109Arg SNP and hypertension were found. Multivariate logistic regression analysis evidenced that A allele carriers of Gln223Arg (AA+AG) showed higher risks of hypertension than GG carriers after adjustment of age and sex (adjusted odds ratio: 1.549, 95% confidence interval: 1.031- 2.036, p=0.035). BMI, fasting serum insulin, oral glucose tolernace test (OGTT)-2h glucose, serum leptin, as well as LDL-cholesterol (LDL-C) levels were also independent risk factors of hypertension in this population. In addition, significant associations were observed between the Gln223Arg and Lys109Arg SNP and serum total cholesterol, LDL-C, and fasting plasma glucose levels in hypertensive patients. Besides, A allele of Gln223Arg had raised diastolic blood pressure, compared with GG carriers (p=0.001). While variance of Lys109Arg was associated with waist-to-hip ratio, OGTT-2h glucose, and homeostasis model assessment of insulin resistance (p<0.05).

CONCLUSIONS

LEPR polymorphisms may be a marker for susceptibility to essential hypertension in Chinese subjects, and be involved in the development of several features including dyslipidemia and impaired glucose regulation in hypertension subjects.

Improvement of glucose tolerance by rhein with restored early-phase insulin secretion in db/db mice

AIMS

In the present study, we investigated whether rhein exerted hypoglycemic action and rhein's effect on the pancreatic β cell in db/db mice.

MATERIALS AND METHODS

Thirty 4-week-old db/db mice were randomized to treatment with rhein (120 mg/kg) (no.=15) and placebo (1% natrium cellulose solution) (no.=15) for 8 weeks, respectively. Fifteen age-matched non-diabetic littermates db/m mice treated with placebo were studied as non-diabetic control. After an 8-week treatment, ip glucose tolerance test (IPGTT) and arginine tolerance test were performed. Area under curve (AUC) of insulin levels in IPGTT was calculated to evaluate insulin secretory function. Immunohistochemical staining of insulin was performed to estimate β cell mass. TUNEL assay was performed to determine β cell apoptosis. Islet isolation and perifusion were performed to evaluate kinetics of insulin release in vitro, especially first-phase insulin.

RESULTS

Compared with control group, AUC of glucose concentrations significantly decreased in the rhein-treated group (p<0.05). Simultaneously, AUC of insulin levels increased in the rhein-treated group (p<0.05), especially in the first 30 min after glucose load. Perifusion showed that the rhein-treated group manifested a significantly increase of first-phase insulin secretion. Immunohistochemical study and TUNEL assay showed that rhein treatment greatly preserved β cell mass and inhibited β cell apoptosis.

CONCLUSIONS

Rhein treatment significantly improved glucose- dependent and independent insulin secretion by preservation of β cell mass and inhibition of β cell apoptosis in db/db mice. The characteristics of rhein may make it a novel therapeutic means for preventing from or curing diabetes in the near future.

Improved glucose-stimulated insulin secretion by intra-islet inhibition of protein-tyrosine phosphatase 1B expression in rats fed a high-fat diet

BACKGROUND

Insulin resistance of pancreatic β-cell itself may be a potential link between systemic insulin resistance and impaired insulin secretion in Type 2 diabetes. Protein tyrosine phosphatase 1B (PTP1B) dephosphorylates tyrosine residues in insulin receptors (IR) and IR substrate (IRS) proteins, and thereby inhibits insulin signaling. Thus the impact of PTP1B expression on β-cell insulin pathway may affect insulin secretory function.

AIM

The aim of the present study was to investigate the effects of intra-islet inhibition of PTP1B expression on glucose-stimulated insulin secretion and potential mechanisms in rats fed a high-fat diet (HFD).

MATERIALS AND METHODS

Twenty 10-week-old Sprague Dawley rats were randomly assigned to a regular diet (RD) or a HFD for 8 weeks. At the end of the 8th week, fasting glucose, fasting insulin concentration and lipid profile were measured and an oral glucose tolerance test was done after 12-h fast. Then islet isolation was performed for static incubation and perifusion. Recombinant adenoviruses containing siPTP1B (Ad-siPTP1B), or siControl (Ad-siControl) sequences were constructed using AdEasy™ system. Islets were transfected and then assigned to the Ad-siPTP1B group, the Ad-siControl group, and mock control group. Real-time RT-PCR and Western blot were used to evaluate the expression level of PTP1B. Western blot of glucose transporter 2 (GLUT-2) and glucokinsase were also done to investigate the β-cell glucose-sensing apparatus. Islets were incubated with Krebs-Ringer bicarbonate containing 2.8 mmol/l glucose then 16.7 mmol/l glucose to evaluate glucose-stimulated insulin secretion (GSIS). Islet perifusion was also performed to evaluate kinetics of insulin release in vitro.

RESULTS

HFD rats manifested modest glucose intolerance compared with RD group. And PTP1B expression in isolated islets of rats in the HFD group was higher than that of the RD group. GSIS was impaired in islets of HFD rats (2.3±0.5-fold as basal for HFD vs 8.1±1.3-fold for RD; p<0.05). Ad-siPTP1B treatment resulted in 73% decrease in PTP1B mRNA levels and 61% decrease in PTP1B protein compared with islets treated with Ad-siControl (p<0.05). Simultaneously, PTP1B inhibition resulted in 4.7±0.8-fold increase of GSIS from basal (vs 1.9±0.1-fold for Ad-siControl, p<0.05). Perifusion showed notable improvement of first-phase insulin secretion by AdsiPTP1B treatment. Significant decrease of both GLUT-2 (by 49.8%) and glucokinase (GCK, by 43.7%) were found in the HFD group when compared with the RD group, while up-regulation of both GLUT-2 (by 98%) and GCK (by 62%) was achieved after PTP1B inhibiton by Ad-siPTP1B.

CONCLUSIONS

Intra-islet PTP1B is an important physiological regulator of glucose-induced insulin release and the characteristics of PTP1B inhibitors in insulin secretion could make it a potential novel therapeutics for protection of β-cell secretory function in Type 2 diabetes.

Waist-to-height ratio, an optimal predictor for obesity and metabolic syndrome in Chinese adults

OBJECTIVE

Anthropometric indices to obesity were evaluated as predictors of metabolic syndrome risk factors. Our purpose was to explore an optimal or more reliable anthropometric indicator and optimal cut-off points for obesity on metabolic syndrome in Chinese adults.

PARTICIPANTS AND METHODS

The survey was conducted involving 2947 participants, aged 20 or above with cross-sectional study of population. The predictive validity and optimal cut-off values were analyzed by receiver operating characteristic (ROC) curves, area under curve (AUC) and the largest Youden's index (sensitivity + specificity - 1) by gender group, respectively. Kappa value showed diagnostic consistency.

RESULTS

According to the criteria of CDS 2004, IDF 2005 and AHA/NHLBI 2005, the prevalence of metabolic syndrome was 10.32%, 9.64% and 16.12% respectively, which indicated that the prevalence was higher in men than in women and increased with age (P < 0.05). The BMI, WC, WHR and WHtR in metabolic syndrome patients were greater than those in healthy volunteers and the indices in men were higher than those in women. With adjusted age and gender, the partial correlation coefficient for BMI-WC, BMI-WHR and BMI-WHtR was 0.7991, 0.5278 and 0.8196, respectively (P < 0.05). The area under curves (AUCs) of receiver operating characteristic (ROC) curves for WHtR was larger (P < 0.05) than that for WC and WHR. The cut-point of WHtR was approximately 0.5 in both genders with a satisfactory balance between sensitivity and specificity, where the Kappa (k) value for WHtR-BMI was higher than that for WHtR-WHR, and WHtR-WC.

CONCLUSIONS

The results indicated that WHtR might be an optimal anthropometric predictor of metabolic syndrome risk factors and the cut-point of WHtR was approximately 0.50 in both genders of Chinese adults.

Protein tyrosine phosphatase 1B gene polymorphisms and essential hypertension: a case-control study in Chinese population

BACKGROUND

Protein tyrosine phosphatase (PTP)- 1B, encoded by the PTPN1 gene, negatively regulates insulin signaling by dephosphorylating the phosphotyrosine residues of the insulin receptor kinase activation segment. Several rare single nucleotide polymorphisms (SNP) have been linked to diseases accompanying insulin resistance such as Type 2 diabetes, obesity, and dyslipidemia in different populations.

AIM

To investigate whether PTP-1B SNP are associated with hypertension and hypertension-related metabolic traits in Chinese subjects.

MATERIALS AND METHODS

A total of 239 Chinese patients with hypertension and 141 non-hypertensive subjects were screened. The genotypes of PTP-1B gene polymorphisms were determined by PCR-restriction fragment length polymorphism methods.

RESULTS

The case-control study showed associations between the frequencies of T allelic g54281 T>A and A allele of I5/37C>A and hypertension (p<0.0001, p=0.0371, respectively). In addition, significant associations were observed between the IVS6+G82A polymorphism and waist circumference, total cholesterol, and LDL-cholesterol levels in hypertensive patients (p=0.0005 approximately 0.0260). And g54281 T allele was associated with higher plasma triglyceride (p=0.0390) and LDL-cholesterol concentration (p=0.0141), while g58585 T>C was associated with body mass index (BMI) (p=0.0308), waist circumference (p=0.0216), and homeostasis model assessment of insulin resistance (p=0.047). Multivariate logistic regression analysis showed that T allele carriers of g54281T>A and A allele carriers of I5/37C>A had higher risks of hypertension independent of age, gender, BMI, glucose levels, and lipids profiles [odds ratio (OR): 1.79, 95% confidence interval (CI): 1.09- 2.96, p=0.02; OR: 1.66, 95% CI: 1.13-2.44, p=0.01, respectively].

CONCLUSIONS

PTP-1B polymorphisms contribute to pathogenesis of hypertension in Chinese subjects and PTP-1B SNP may be involved in the development of several features including dyslipidemia and obesity in hypertensive subjects.

Femtosecond laser-drilling-induced HgCdTe photodiodes

Femtosecond-laser drilling may induce holes in HgCdTe with morphology similar to that induced by ion-milling in loophole technique. So-formed hole structures are proven to be pn junction diodes by the laser beam induced current characterization as well as the conductivity measurement. Transmission and photoluminescence spectral measurements on a n-type dominated hole-array structure give rise to different results from those of an ion-milled sample.

Vaginal delivery of protein drugs in rats by gene-transformed Lactococcus lactis

A probiotic bacterium, Lactococcus lactis subsp. lactis (L. lactis) transformed with plasmid ss80, which made it capable of synthesizing and secreting β-lactamase, a 29 kDa protein, was used to deliver β-lactamase via vaginal route. The vaginal absorption of β-lactamase in rats was studied when delivered by this L. lactis system and compared to the β-lactamase solution with or without the untransformed L. lactis. The vaginal administration of 1.2 × 10(7), 3 × 10(7), and 8 × 10(7) colony forming units (cfu) of L. lactis resulted in the amount absorbed of 77, 194, and 216 mU, with the respective doses. C(max), mean retention time and mean absorption time of β-lactamase were also increased with the increase in the cfu of L. lactis administered. These results have demonstrated that L. lactis can significantly increase (p < 0.01) the β-lactamase vaginal absorption as compared to the β-lactamase solution, which is probably due to the adhesion of L. lactis to and continuous synthesis and delivery of β-lactamase directly to the vaginal mucosa. In conclusion, transformed normal flora may be an efficient method to deliver protein drugs through the vaginal route.

The phospholipase A(2) inhibitor methyl indoxam suppresses diet-induced obesity and glucose intolerance in mice

BACKGROUND AND PURPOSE

Previous results have shown that mice lacking in the group 1B phospholipase A(2) (Pla2g1b) are resistant to obesity and diabetes induced by feeding a diabetogenic high-fat/high-carbohydrate diet. This study examined the potential of using the Pla2g1b inhibitor methyl indoxam as therapy to suppress diet-induced obesity and diabetes.

EXPERIMENTAL APPROACH

Male C57BL/6 mice were fed the diabetogenic diet with or without methyl indoxam supplementation. Body weight gain, fasting plasma glucose levels, glucose tolerance and postprandial lysophospholipid absorption were compared.

KEY RESULTS

Wild-type C57BL/6 mice fed the diabetogenic diet without Pla2g1b inhibitor showed 31 and 69% body weight gain after 4 and 10 weeks respectively. These animals also showed elevated plasma glucose levels and were glucose intolerant. In contrast, C57BL/6 mice fed the diabetogenic diet with 90 mg.kg(-1) of methyl indoxam gained only 5% body weight after 10 weeks. These animals were also euglycaemic and displayed normal glucose excursion rates in glucose tolerance test. Methyl indoxam suppression of diet-induced body weight gain and glucose intolerance was correlated with the inhibition of Pla2g1b-mediated postprandial lysophospholipid absorption.

CONCLUSIONS AND IMPLICATIONS

These results show that oral supplementation of a diabetogenic diet with the Pla2g1b inhibitor methyl indoxam effectively suppresses diet-induced obesity and diabetes in mice. This suggests that Pla2g1b inhibition may be a potentially effective oral therapeutic option for treatment of obesity and diabetes.

Computational identification of protein methylation sites through bi-profile Bayes feature extraction

Protein methylation is one type of reversible post-translational modifications (PTMs), which plays vital roles in many cellular processes such as transcription activity, DNA repair. Experimental identification of methylation sites on proteins without prior knowledge is costly and time-consuming. In silico prediction of methylation sites might not only provide researches with information on the candidate sites for further determination, but also facilitate to perform downstream characterizations and site-specific investigations. In the present study, a novel approach based on Bi-profile Bayes feature extraction combined with support vector machines (SVMs) was employed to develop the model for Prediction of Protein Methylation Sites (BPB-PPMS) from primary sequence. Methylation can occur at many residues including arginine, lysine, histidine, glutamine, and proline. For the present, BPB-PPMS is only designed to predict the methylation status for lysine and arginine residues on polypeptides due to the absence of enough experimentally verified data to build and train prediction models for other residues. The performance of BPB-PPMS is measured with a sensitivity of 74.71%, a specificity of 94.32% and an accuracy of 87.98% for arginine as well as a sensitivity of 70.05%, a specificity of 77.08% and an accuracy of 75.51% for lysine in 5-fold cross validation experiments. Results obtained from cross-validation experiments and test on independent data sets suggest that BPB-PPMS presented here might facilitate the identification and annotation of protein methylation. Besides, BPB-PPMS can be extended to build predictors for other types of PTM sites with ease. For public access, BPB-PPMS is available at http://www.bioinfo.bio.cuhk.edu.hk/bpbppms.

Sociodemographic characteristics and perinatal mortality among singletons in North East Tanzania: a registry-based study

OBJECTIVES

Sub-Saharan Africa has the highest known perinatal mortality rates in the World, but few studies have assessed the importance of parental sociodemographic characteristics on perinatal mortality in this region. The aim of this study was to estimate how sociodemographic patterns affect perinatal mortality in Northern Tanzania.

DESIGN AND SETTINGS

A registry-based study using births from 1999 to 2006 at a hospital in North Eastern Tanzania.

PARTICIPANTS AND METHODS

14 394 singleton births with birthweight 500 g or higher and a known perinatal survival status. Births of women with residence outside the local district who were referred to the hospital for delivery for medical reasons were excluded.

RESULTS

Perinatal mortality was 41.1 per 1000 births. Factors independently associated with higher perinatal mortality were: higher paternal age (> 45) compared to age 26-35 (adjusted relative risk (ARR) 2.0; 95% CI 1.4 to 2.8), low paternal education (only primary) compared to secondary or higher (ARR 1.3; 95% CI 1.1 to 1.7), paternal ethnicity other than Chagga or Pare (ARR 1.4; 95% CI 1.1 to 1.7), paternal farming occupation (ARR 1.5; 95% CI 1.1 to 2.2), maternal service occupation (ARR 1.7; 95% CI 1.2 to 2.6), maternal height 150 cm or lower (ARR 1.4; 95% CI 1.0 to 1.8) and residence in the rural or semi-urban area (ARR 1.4; 95% CI 1.1 to 1.7).

CONCLUSIONS

There are strong sociodemographic gradients in perinatal mortality in Africa. Paternal social characteristics appear to have stronger influence on perinatal mortality than maternal characteristics. This may reflect social and cultural conditions that need to be considered by policymakers in developing countries.

Comparative oxygen radical formation and toxicity of BDE 47 in rainbow trout cell lines

The polybrominated diphenyl ethers (PBDEs) constitute a class of flame retardants whose residues have markedly increased in fish and human tissues during the last decade. In particular, the levels of certain PBDE congeners in salmon have raised concern regarding potential risks associated with dietary PBDE exposures. However, little is known regarding PBDE-mediated cell injury in relevant in vitro cell models. We conducted a comparative study of oxyradical production and cell injury in rainbow trout gill (RTgill-W1) and trout liver cells (RTL-W1) exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE 47), a predominant BDE residue found in fish tissues such as salmonids. Exposure to low micromolar concentrations of BDE 47 elicited a significant loss in RTgill-W1 and RTL-W1 cell viability as measured by alamarBlue assay. The dose-response of BDE toxicity differed among the two cell lines, with the RTL-W1 liver cells showing greater resistance to toxicity at lower BDE 47 doses, but a more dramatic loss of viability relative to gill cells when challenged with higher (50 microM) doses. The sensitivity of the trout liver cells at higher BDE 47 exposures was reflected by a higher basal production of oxygen radical production by 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence that was markedly enhanced in the presence of BDE 47, suggesting an overwhelming of trout liver cell antioxidant defense pathways. Collectively, our data indicate that RTgill-W1 and RTL-W1 liver cells are sensitive to BDE 47-mediated cell injury through a mechanism that may involve oxidative stress. Our data also provide an in vitro basis for potential tissue differences in BDE 47-mediated cell injury.

Role of tropomyosin as a cross-reacting allergen in sensitization to cockroach in patients from Martinique (French Caribbean island) with a respiratory allergy to mite and a food allergy to crab and shrimp

BACKGROUND

Tropomyosin has been described as cross-reacting allergen between mite, cockroach and shrimp.

METHODS

In 13 patients with asthma and/or rhinitis sensitized to mite and/or German cockroach and presenting urticaria, oral allergy syndrome or angio-edema upon eating shrimp and/or crab, we measured specific IgE to mite, cockroach, crab and shrimp tropomyosin.

RESULTS

Ten patients had specific IgE to tropomyosin from mite, 8 from shrimp, 6 from crab and 5 from cockroach. AST inhibition tests indicated that mite allergen is a primary sensitizer and is cross-reacting with shrimp, crab and cockroach allergens.

CONCLUSION

Tropomyosin could be the cross-reacting allergen relevant for clinical symptoms to mite, cockroach, shrimp and crab.

Ribonucleotide reductase inhibitors and future drug design

Ribonucleotide reductase (RR) is a multisubunit enzyme responsible for the reduction of ribonucleotides to their corresponding deoxyribonucleotides, which are building blocks for DNA replication and repair. The key role of RR in DNA synthesis and cell growth control has made it an important target for anticancer therapy. Increased RR activity has been associated with malignant transformation and tumor cell growth. Efforts for new RR inhibitors have been made in basic and translational research. In recent years, several RR inhibitors, including Triapine, Gemcitabine, and GTI-2040, have entered clinical trial or application. Furthermore, the discovery of p53R2, a p53-inducible form of the small subunit of RR, raises the interest to develop subunit-specific RR inhibitors for cancer treatment. This review compiles recent studies on (1) the structure, function, and regulation of two forms of RR; (2) the role in tumorigenesis of RR and the effect of RR inhibition in cancer treatment; (3) the classification, mechanisms of action, antitumor activity, and clinical trial and application of new RR inhibitors that have been used in clinical cancer chemotherapy or are being evaluated in clinical trials; (4) novel approaches for future RR inhibitor discovery.

Crystal structure of bis(1,3-diaminepropane)carbonatomanganese(III) chloride monohydrate, [Mn(C3H10N2)2(CO3)]Cl · H2O

C7H22ClMnN4O4, monoclinic, P121/n1 (no. 14), a = 8.997(2) Å, b = 6.781(2) Å, c = 21.398(6) Å, β = 91.81(1)°, V = 1304.8 Å3, Z = 4, Rgt(F) = 0.047, wRref(F2) = 0.132, T = 293 K.

Antisense Smo under the control of the PTCH1 promoter delivered by an adenoviral vector inhibits the growth of human pancreatic cancer

Hedgehog (Hh) signaling pathway is crucial in growth and patterning during embryonic development. Recent data have shown an association of its activation with cancer formation and maintenance. A ligand-dependent activation, where Hh components (SHH, PTCH1, Smo and GLi1) are aberrantly expressed with PTCH1 being a negative feedback regulator, is a newly identified mechanism for pancreatic carcinogenesis. In this study, we developed a cell-specific cytotoxic model for the treatment of human pancreatic cancer (HPC) in which expression of antisense Smo (SAS) was under the control of the PTCH1 promoter (ptch/p) delivered by an adenoviral vector (Ad-ptch/p-SAS). We observed that the cell-specific cytotoxicity in HPC cells depended on the expressions of inherent PTCH1, Smo and GLi1 in the target cells in which the Hh pathway was presumed to be activated. Fluorescence-activated cell sorting analysis indicated that the cell death was apoptosis. Western blot showed that Smo protein in the infected cells significantly decreased. Furthermore, an in vivo experiment demonstrated that such Hh activity-cell-specific cytotoxicity was achieved by daily intratumoral injection of Ad-ptch/p-SAS (10(9) plaque-forming unit) for 5 days. Our study suggests that targeting at the Hh signaling pathway may be an effective novel gene therapeutic strategy alone or in combination with other agents for the treatment of pancreatic cancer.

An RNA folding algorithm including pseudoknots based on dynamic weighted matching

On the basis of maximum weighted matching (MWM) algorithm, we introduced a dynamic weight related with stem length and used a recursive algorithm to predict RNA secondary structures by searching the stem structure with maximum weight summation step-by-step. This algorithm not only avoids the complicated free energy calculation, but also it could attain higher prediction accuracy. Moreover, our algorithm can predict most types of potential pseudoknots in the RNA structure.

Alterations in intracerebral hemorrhage-induced brain injury in the iron deficient rat

BACKGROUND

Iron contributes to brain edema and cellular toxicity after intracerebral hemorrhage (ICH). Knowledge regarding ICH in the context of iron deficiency anemia (IDA), a common nutritional disorder, is limited.

OBJECTIVE

To determine the effect of IDA on brain and behavioral outcome after ICH in rats.

METHODS

Six-week-old male rats (n = 75) were randomized to non-IDA or IDA groups. After 1 month of iron sufficient or deficient diets, 100 microl autologous blood was infused into the right basal ganglia (BG). Brains were assessed for iron concentration, regional water content, BG transferrin, and transferrin receptor concentrations after ICH. Recovery of upper extremity sensorimotor function was assessed. Brain and behavioral variables were compared by diet group. Significance was set at p < 0.05.

RESULTS

Whole brain iron was decreased and water content was increased for IDA rats in injured cortex and BG at day 3 (p < 0.05) compared with non-IDA rats. Transferrin and transferrin receptor content were increased in injured BG for IDA compared to non-IDA in the first week after ICH (p < 0.05). IDA rats had greater left vibrissae-stimulated forelimb-placing deficits and forelimb-use asymmetry than non-IDA after ICH (p < 0.05).

CONCLUSIONS

Brain iron status may be an important determinant of injury severity and recovery after ICH.

Therapeutic Actions of an Insulin Receptor Activator and a Novel Peroxisome Proliferator-Activated Receptor γ Agonist in the Spontaneously Hypertensive Obese Rat Model of Metabolic Syndrome X

Insulin resistance clusters with hyperlipidemia, impaired glucose tolerance, and hypertension as metabolic syndrome X. We tested a low molecular weight insulin receptor activator, demethylasterriquinone B-1 (DMAQ-B1), and a novel indole peroxisome proliferator-activated receptor gamma agonist, 2-(2-(4-phenoxy-2-propylphenoxy)ethyl)indole-5-acetic acid (PPEIA), in spontaneously hypertensive obese rats (SHROB), a genetic model of syndrome X. Agents were given orally for 19 days. SHROB showed fasting normoglycemia but impaired glucose tolerance after an oral load, as shown by increased glucose area under the curve (AUC) [20,700 mg x min/ml versus 8100 in lean spontaneously hypertensive rats (SHR)]. Insulin resistance was indicated by 20-fold excess fasting insulin and increased insulin AUC (6300 ng x min/ml versus 990 in SHR). DMAQ-B1 did not affect glucose tolerance (glucose AUC = 21,300) but reduced fasting insulin 2-fold and insulin AUC (insulin AUC = 4300). PPEIA normalized glucose tolerance (glucose AUC = 9100) and reduced insulin AUC (to 3180) without affecting fasting insulin. PPEIA also increased food intake, fat mass, and body weight gain (81 +/- 12 versus 45 +/- 8 g in untreated controls), whereas DMAQ-B1 had no effect on body weight but reduced subscapular fat mass. PPEIA but not DMAQ-B1 reduced blood pressure. In skeletal muscle, insulin-stimulated phosphorylation of the insulin receptor and insulin receptor substrate protein 1-associated phosphatidylinositol 3-kinase activity were decreased by 40 to 55% in SHROB relative to lean SHR. PPEIA, but not DMAQ-B1, enhanced both insulin actions. SHROB also showed severe hypertriglyceridemia (355 +/- 42 mg/dl versus 65 +/- 3 in SHR) attenuated by both agents (DMAQ-B1, 228 +/- 18; PPEIA, 79 +/- 3). Both these novel antidiabetic agents attenuate insulin resistance and hypertriglyceridemia associated with metabolic syndrome but via distinct mechanisms.

Biofilm Formation by Neisseria gonorrhoeae

Studies were performed in continuous-flow chambers to determine whether Neisseria gonorrhoeae could form a biofilm. Under these growth conditions, N. gonorrhoeae formed a biofilm with or without the addition of 10 microM sodium nitrite to the perfusion medium. Microscopic analysis of a 4-day growth of N. gonorrhoeae strain 1291 revealed evidence of a biofilm with organisms embedded in matrix, which was interlaced with water channels. N. gonorrhoeae strains MS11 and FA1090 were found to also form biofilms under the same growth conditions. Cryofield emission scanning electron microscopy and transmission electron microscopy confirmed that organisms were embedded in a continuous matrix with membranous structures spanning the biofilm. These studies also demonstrated that N. gonorrhoeae has the capability to form a matrix in the presence and absence of CMP-N-acetylneuraminic acid (CMP-Neu5Ac). Studies with monoclonal antibody 6B4 and the lectins soy bean agglutinin and Maackia amurensis indicated that the predominate terminal sugars in the biofilm matrix formed a lactosamine when the biofilm was grown in the absence of CMP-Neu5Ac and sialyllactosamine in the presence of CMP-Neu5Ac. N. gonorrhoeae strain 1291 formed a biofilm on primary urethral epithelial cells and cervical cells in culture without loss of viability of the epithelial cell layer. Our studies demonstrated that N. gonorrhoeae can form biofilms in continuous-flow chambers and on living cells. Studies of these biofilms may have implications for understanding asymptomatic gonococcal infection.

Nontypeable Haemophilus influenzae strain 2019 produces a biofilm containing N-acetylneuraminic acid that may mimic sialylated O-linked glycans

Previous studies suggested that nontypeable Haemophilus influenzae (NTHI) can form biofilms during human and chinchilla middle ear infections. Microscopic analysis of a 5-day biofilm of NTHI strain 2019 grown in a continuous-flow chamber revealed that the biofilm had a diffuse matrix interlaced with multiple water channels. Our studies showed that biofilm production was significantly decreased when a chemically defined medium lacking N-acetylneuraminic acid (sialic acid) was used. Based on these observations, we examined mutations in seven NTHI strain 2019 genes involved in carbohydrate and lipooligosaccharide biosynthesis. NTHI strain 2019 with mutations in the genes encoding CMP-N-acetylneuraminic acid synthetase (siaB), one of the three NTHI sialyltransferases (siaA), and the undecaprenyl-phosphate alpha-N-acetylglucosaminyltransferase homolog (wecA) produced significantly smaller amounts of biofilm. NTHI strain 2019 with mutations in genes encoding phosphoglucomutase (pgm), UDP-galactose-4-epimerase, and two other NTHI sialyltransferases (lic3A and lsgB) produced biofilms that were equivalent to or larger than the biofilms produced by the parent strain. The biofilm formed by the NTHI strain 2019pgm mutant was studied with Maackia amurensis fluorescein isothiocyanate (FITC)-conjugated and Sambucus nigra tetramethyl rhodamine isocyanate (TRITC)-conjugated lectins. S. nigra TRITC-conjugated lectin bound to this biofilm, while M. amurensis FITC-conjugated lectin did not. S. nigra TRITC-conjugated lectin binding was inhibited by incubation with alpha2,6-neuraminyllactose and by pretreatment of the biofilm with Vibrio cholerae neuraminidase. Matrix-assisted laser desorption ionization-time of flight mass spectometry analysis of lipooligosaccharides isolated from a biofilm, the planktonic phase, and plate-grown organisms showed that the levels of most sialylated glycoforms were two- to fourfold greater when the lipooligosaccharide was derived from planktonic or biofilm organisms. Our data indicate that NTHI strain 2019 produces a biofilm containing alpha2,6-linked sialic acid and that the sialic acid content of the lipooligosaccharides increases concomitant with the transition of organisms to a biofilm form.

Phosphatidylinositol 3-kinase mediates proliferative signals in intestinal epithelial cells

BACKGROUND AND AIMS

Determination of intracellular signalling pathways that mediate intestinal epithelial proliferation is fundamental to the understanding of the integrity and function of the intestinal tract under normal and diseased conditions. The phosphoinositide 3-kinase (PI3K)/Akt pathway transduces signals initiated by growth factors and is involved in cell proliferation and differentiation. In this study, we assessed the role of PI3K/Akt in transduction of proliferative signals in intestinal epithelial cells.

METHODS

A rat intestinal epithelial (RIE) cell line and human colorectal cancer HCA-7 and LS-174 cell lines served as in vitro models. The Balb/cJ mouse was the in vivo model.

RESULTS

PI3K activation was critical for G1 cell cycle progression of intestinal epithelial cells. Ectopic expression of either active p110alpha or Akt-1 increased RIE cell proliferation. In vivo experiments demonstrated that PI3K activation was closely associated with the proliferative activity of intestinal mucosa. Treatment of mice with PI3K inhibitors blocked induction of PI3K activity and attenuated intestinal mucosal proliferation associated with oral intake. Epidermal growth factor and transforming growth factor alpha stimulated PI3K activation which was required for growth factor induced expression of cyclin D1.

CONCLUSIONS

The PI3K/Akt pathway transduces mitogenic signals from growth factor receptors to the cell cycle machinery and plays a critical role in regulation of intestinal epithelial proliferation.

[Establishment of Hymenolepis diminuta-animal model and morphology of cysticercoid]

AIM

To observe the morphological changes in the process of the development of Hymenolepis diminuta.

METHODS

The life cycle of Hymenolepis diminuta was established between Rattus domesticus albus and Triboliun castaneum. The morphology of cysticercoid were observed microscopically, and the ultrastructure of the body surface of cysticercoid were observed by scanning electron microscopy.

RESULTS

Three phases including the mature stage, the blister stage and the protective outer membrane-forming stage during the growing course of cysticercoid were observed microscopically. Under scanning electron microscope, lots of sieve-like micropores on the surface of mature cysticercoid were seen in the second week after infection. The blister phase was found in the third week and the outer membrane measuring about 45 microns in thickness were found surrounding the cysticercoid and vesicular surface, forming a smooth cyst wall in the fourth week.

CONCLUSION

The life cycle of Hymenolepis diminuta has been established in the animal-model. The finding of the three phases during the growing course of cysticercoid is reported for the first time.

Apical barriers to airway epithelial cell gene transfer with amphotropic retroviral vectors

Gene transfer to airway epithelia with amphotropic pseudotyped retroviral vectors is inefficient following apical vector application. To better understand this inefficiency, we localized the expression of Pit2, the amphotropic receptor, in polarized human airway epithelia. Pit2 was expressed on both the apical and basolateral surfaces of the cells, suggesting that factors other than receptor abundance may limit apical gene transfer efficiency. Binding studies performed with radiolabeled amphotropic MuLV suggested that the apically applied virus binds to Pit2. Hypothetical barriers to retroviral gene transfer include the apical glycocalyx and other secreted products of epithelia. In this study, we demonstrated that sialic acid, keratan sulfate and collagen type V are present on the apical surface of well-differentiated human airway epithelia. While enzyme treatment reduced the abundance of these components, the treatment also decreased the transepithelial resistance to approximately 35% of the controls, suggesting that the epithelial integrity was impaired. To attain an airway epithelial culture with a modified apical surface and intact epithelial integrity, we utilized 100 mM 2-deoxy-D-glucose, a glycosylation inhibitor, to prevent the glycocalyx from reforming following enzyme treatment. This approach allowed the resistance, but not the apical glycocalyx to recover. Despite this physical modification of the cell surface, the amphotropic retroviral vector failed to transduce airway epithelia following apical application. These results suggest that factors other than apical receptor abundance and the glycocalyx inhibit amphotropic retroviral gene transfer in human airway epithelia.