Oxytocin-induced membrane hyperpolarization in pain-sensitive dorsal root ganglia neurons mediated by Ca(2+)/nNOS/NO/KATP pathway

Oxytocin (OT) plays an important role in pain modulation and antinociception in the central nervous system. However, little is known about its peripheral effects. This study was conducted to investigate the effect of OT on the electrical properties of neurons in the dorsal root ganglia (DRG) and the underlying mechanisms. DRG neurons from adult rats were acutely dissociated and cultured. Intracellular Ca(2+) was determined by fluorescent microscopy using an indicator dye. The electrical properties of DRG neurons were tested by patch-clamp recording. The oxytocin receptor (OTR) and neuronal nitric oxide synthase (nNOS) on DRG neurons were assessed with immunofluorescence assays. OTR co-localized with nNOS in most of Isolectin B4 (IB4)-binding cultured DRG neurons in rats. OT decreased the excitability, increased the outward current, and evoked the membrane hyperpolarization in cultured DRG neurons. Sodium nitroprusside (SNP), the donor of nitric oxide (NO), exerted similar effects as OT on the membrane potential of cultured DRG neurons. OT increased the production of NO in DRGs and cultured DRG neurons. Pre-treatment of the OTR antagonist atosiban or the selective nNOS inhibitor N-Propyl-l-arginine (NPLA) significantly attenuated the hyperpolarization effect evoked by OT. OT produced a concentration-dependent increase in intracellular Ca(2+) in DRG neurons that responds to capsaicin, which can be attenuated by atosiban, but not by NPLA. OT-evoked membrane hyperpolarization and increase of outward current were distinctly attenuated by glibenclamide, a blocker of ATP-sensitive K(+) (KATP) channel. OT might be an endogenous antinociceptive agent and the peripheral antinociceptive effects of OT are mediated by activation of the Ca(2+)/nNOS/NO/KATP pathway in DRG neurons.

Oxytocin down-regulates mesenteric afferent sensitivity via the enteric OTR/nNOS/NO/KATP pathway in rat

BACKGROUND

Oxytocin plays an analgesic role in modulation of nociception and pain. Most work to date has focused on the central mechanisms of oxytocin analgesia, but little is known about whether peripheral mechanisms are also involved.

METHODS

The mesenteric afferent discharge was recorded in vitro. The expressions of oxytocin receptor (OTR) and neuronal nitric oxide synthase (nNOS) in longitudinal muscle myenteric plexus (LMMP) was identified by immunofluorescence.

KEY RESULTS

Oxytocin per se had no effect on the jejunal mesenteric afferent discharge, however, it markedly attenuated the bradykinin- or distention-evoked increase of mesenteric afferent discharge, which was mimiced by the nitric oxide (NO) donor sodium nitroprusside (SNP). Pretreatment of either NOS inhibitor L-NAME or NPLA largely reduced the inhibitory effect of oxytocin on bradykinin-evoked mesenteric afferent discharge. Such effect, to a large extent, was also alleviated by N-and P-type voltage-dependent calcium channel antagonists or KATP blocker glibenclamide. In addition, immunofluorescence studies show strong colocalization of OTR with nNOS in LMMP of the rat jejunum.

CONCLUSIONS & INFERENCES

Oxytocin down-regulates the mesenteric afferent sensitivity through nNOS-NO-KATP pathway. Our findings may reveal a new peripheral mechanism for oxytocin analgesia.

A new target for the old regulator: H-NS suppress T6SS secretory protein EvpP, the major virulence factor in the fish pathogen Edwardsiella tarda

The evpP gene in fish pathogen Edwardsiella tarda, coding the T6SS secretory protein EvpP and carrying an evpA-evpO independent promoter region, was crucial for host cell invasion. The transcription of evpP was positively regulated by either the two-component system EsrA-EsrB or iron concentration, and its overexpression was known to enhance the invasion ability in our previous study. This work demonstrated that the H-NS protein, a pleiotropic regulator of gene expression, was a new transcriptional modulator of evpP gene. The results showed that in vivo the transcriptional level of evpP was downregulated by H-NS and in vitro this global regulator interacted directly with evpP promoter region. Moreover, DNase I footprinting experiments mapping the interaction regions of H-NS and evpP revealed that this global regulator bound to evpP promoter and neighbouring areas at multiple sites. We provided a new insight into evpP regulation network and demonstrated the repression of H-NS to the transcription of evpP gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

Recently, the devastating fish disease edwardsiellosis caused by Edwardsiella tarda has been widely concerned. The xenogeneic silencing of the classic regulator H-NS to the T6SS secretory protein EvpP, which played an important role in the virulence of Edw. tarda, was firstly reported in this study. It raised a better understanding of the virulence regulation of EvpP and provided more information about the complex infection mechanism of this pathogen. Our findings would contribute to the development of live attenuated vaccines against edwardsiellosis thus reducing the economic losses caused by this bacterium.

Prevalence and characterization of Salmonella enterica in dried milk-related infant foods in Shaanxi, China

The aim of this study was to investigate the existence and characteristics of Salmonella enterica in dried milk-related infant foods. Twenty-four (3.4%) of 705 samples, including 5 (2.0%) of 246 powdered infant formula, 18 (4.0%) of 445 infant rice cereal, and 1 (7.1%) of 14 other infant foods, were positive for Salmonella. Fifteen serotypes were identified in 40 Salmonella isolates; Salmonella Duesseldorf (15.0%) and Salmonella Indiana (15.0%) were more frequently detected than other serotypes. Resistance to chloramphenicol (82.5%) was most common, followed by tetracycline (57.5%), ceftiofur (52.5%), kanamycin (52.5%), streptomycin (50.0%), gentamycin (45.0%), nalidixic acid (35.0%), ceftriaxone (32.5%), ciprofloxacin (25.0%), amikacin (20.0%), and cefoxitin (15.0%). Twenty-eight (70.0%) isolates were resistant to ≥ 8 antimicrobials, with 5 (12.5%) being resistant to 14 antimicrobials. Amino acid substitutions in gyrase A (GyrA) were most frequently detected as Ser83Arg/Asp87Glu and in p53-associated Parkin-like cytoplasmic protein (ParC), they were all Ser80Arg; the quinolone resistance gene qnrS (47.5%) was commonly detected as well as aminoglycoside acetyltransferase [aac(6')-Ib; 25.0%], qnrA (17.5%), and qnrB (15.0%) genes. Thirty distinct pulsed-field gel electrophoresis patterns were identified among 40 isolates; no identical pulsed-field gel electrophoresis pattern was detected among Salmonella isolates with the same serovar that was recovered in 2010 and 2012. Our results suggest that dried milk-related infant foods could be contaminated with Salmonella and highlight that the dangers to infant health should not be neglected.

Association between polymorphisms in ADAM33, CD14, and TLR4 with asthma in the Uygur population in China

We evaluated the associations between single nucleotide polymorphisms (SNPs) and haplotypes of the genes encoding a disintegrin and metalloproteinase 33 (ADAM33), cluster of differentiation 14 (CD14), and Toll-like receptor 4 (TLR4) and the susceptibility of developing specific adult phenotypes of bronchial asthma in a Chinese Uygur population. Five SNPs of ADAM33 (T1, T2, and V4), 3 SNPs of CD14 (-1359G/T, -1145G/A, and -159T/C), and 2 SNPs of TLR4 (-896A/G and -1196C/T) were genotyped in a Chinese Uygur sample of 126 adult asthmatic patients and 126 control subjects. Gene polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism analysis. The genotyping results were confirmed in a random subgroup of our samples using direct DNA sequencing. The allele frequencies of ADAM33 T1 (TC), T2 (AG), and V4 (GG) were significantly higher in patients than in controls (P<0.05). The genotypes T1 (TC+CC), T2 (AG+AA), and V4 (CG+GG) significantly increased the risk of asthma. After adjusting for confounding factors, these associations were stronger and remained significant. The T1 (TC) and V4 (GG) genotypes in the ADAM33 gene were associated with significantly decreased FEV1 levels in patients with asthma. The haplotype frequencies of Hap3 (CAC) and Hap4 (CAG) were significantly higher in patients than in controls (P<0.05). Our results suggest that polymorphisms T1, T2, and V4 in ADAM33 may contribute to the susceptibility to asthma. Specific haplotypes of ADAM33 may contribute to a higher susceptibility to asthma in the Chinese Uygur population.

Vibrational Excitations and Low Energy Electronic Structure of Epoxide-decorated Graphene

We report infrared studies of adsorbed atomic oxygen (epoxide functional groups) on graphene. Two different systems are used as a platform to explore these interactions, namely, epitaxial graphene/SiC(0001) functionalized with atomic oxygen (graphene epoxide, GE) and chemically reduced graphene oxide (RGO). In the case of the model GE system, IR reflectivity measurements show that epoxide groups distort the graphene π bands around the K-point, imparting a finite effective mass and contributing to a band gap. In the case of RGO, epoxide groups are found to be present following the reduction treatment by a combination of polarized IR reflectance and transmittance measurements. Similar to the GE system, a band gap in the RGO sample is observed as well.

Overexpression of RhoGDI, a novel predictor of distant metastasis, promotes cell proliferation and migration in hepatocellular carcinoma

RhoGDI (Rho GDP-dissociation inhibitor alpha, or RhoGDIα) was identified as a regulator of Rho GTPases, but its role in cancer remains controversial. In this study, increased expression of RhoGDI was detected in hepatocellular carcinoma (HCC) cell lines and tissues with highly metastatic potential. RhoGDI overexpression correlated with postoperative distant metastasis. Enforced expression of RhoGDI in HCC cells significantly enhanced cell proliferation and migration. Conversely, knockdown of RhoGDI caused an inhibition of the aggressive phenotypes of HCC cells. Furthermore, RhoGDI up-regulated Rho, but not Rac, and enhanced PI3K/AKT and MAPK pathway activity. Our findings suggest that RhoGDI overexpression is a predictor of distant metastasis and plays an important role in the progression of HCC.

A sensitive and specific nanoparticle-assisted PCR assay for rapid detection of porcine parvovirus

A novel nanoparticle-assisted polymerase chain reaction (nanoPCR) assay to detect porcine parvovirus (PPV) is described here. Primers for this assay were designed based on the conserved region of the nonstructural protein 1 (NS1) gene of PPV, which encodes one of the nonstructural proteins. The sensitivity of the PPV nanoPCR assay was measured by using diluted recombinant plasmids in which the PPV NS1 gene had been inserted. The detection limit was 5.6 × 10(1) copies μl(-1) for the PPV nanoPCR assay vs 5.6 × 10(3) copies μl(-1) for conventional PCR assay. The results showed that the sensitivity of PPV nanoPCR assay was 100 times higher than that of conventional PCR assay. The PPV nanoPCR assay produced 142-bp product as expected when amplifying PPV DNA, while produced nothing when amplifying the DNA or cDNA of the following viruses: swine encephalomyocarditis virus, classical swine fever virus, porcine pseudorabies virus, porcine reproductive and respiratory syndrome virus, porcine teschovirus and porcine circovirus type II. PPV was detected in 108 of 109 clinical swine samples from Heilongjiang, Jilin and Henan provinces using the nanoPCR assay, and the results were confirmed by sequencing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Nanoparticle-assisted polymerase chain reaction (nanoPCR) assay is an improved PCR. NanoPCR is highly sensitive and specific because the nanofluids formed in the nanobuffer have high thermal conductivity, which reduces the time required to reach the target temperature. It is more sensitive than conventional PCR, and it could detect the cases earlier than conventional PCR. This report describes the first application of the highly efficient nanoPCR technology for the detection of porcine parvovirus (PPV). The PPV nanoPCR assay will be useful for the detection and study of PPV and will also be applicable to improve the detection of other viruses.

DNA double-strand break repair is activated in carotid artery restenosis

Carotid stenosis is a narrowing or constriction of the inner surface of the carotid artery, usually caused by atherosclerosis. In the past decades, carotid angioplasty and stenting (CAS) has been developed into a credible option for the patients with carotid stenosis. However, restenosis remains a severe and unsolved issue after CAS treatment. Currently, the molecular mechanisms involved in the restenosis are still largely unclear. In this study, we found that the double-strand DNA breaks (DSBs) were induced by oxidative stress in the human carotid artery with restenosis by examining the level of γH2AX in the artery tissues. We further analyzed the activation of DNA damage repair pathways in the carotid restenosis. Our results suggest that non-homologues end joining (NHEJ), but not homologous recombination (HR), is mainly activated in the artery tissues with restenosis. Our results may provide clues to develop a new therapeutic strategy for carotid artery restenosis following CAS treatment.

Intrapleural hyperthermic perfusion using distilled water at 48 °C for malignant pleural effusion

BACKGROUND

To evaluate the feasibility, safety and preliminary efficacy of B-ultrasound-guided continuous circulatory intrapleural hyperthermic perfusion (IHP) with distilled water (DW) at 48 °C, for the treatment of malignant pleural effusion (MPE).

METHODS

Prospective, randomized interventional study in China (from December 2008 to December 2011) in adults with MPE originating from disseminated pleural tumor.

EXCLUSION CRITERIA

thoracotomy or surgical resection, limited encapsulated pleural effusion or extensive pleural adhesions. Patients were randomly divided into DW (12 patients; B-ultrasound-guided IHP with 48 °C DW) and PSS-C (11 patients; B-ultrasound-guided IHP with 45 °C physiological saline solution and cisplatin) groups. Patients were followed up for assessment of objective MPE remission rate, Karnofsky performance scale (KPS) scores and survival duration.

RESULTS

Pleural effusion was controlled in 100 % of patients, and mean KPS score was increased by 40 % after therapy. Patients' median survival times in the DW and PSS-C groups were 13.0 and 12.9 months, respectively. No serious clinical complications were observed. There were no significant differences between groups in the total objective MPE remission rate, mean KPS score change or median survival time, demonstrating the achievement of significant clinical efficacy with our modified IHP.

CONCLUSION

Intrapleural hyperthermic perfusion with 48 °C DW is feasible, easy to perform and relatively safe. This method may offer excellent local control for patients with MPE secondary to disseminated pleural lesions.

miR-133a represses tumour growth and metastasis in colorectal cancer by targeting LIM and SH3 protein 1 and inhibiting the MAPK pathway

In recent studies of microRNA expression, miR-133a deregulation was identified in colorectal carcinoma (CRC). However, the mechanisms underlying the pathogenesis and progression of CRC are poorly understood. We found that miR-133a expression was usually down-regulated in CRC cell lines and tissue specimens. Ectopic miR-133a expression inhibited cell proliferation and cell migration. Stable overexpression of miR-133a was sufficient to suppress tumour growth and intrahepatic and pulmonary metastasis in vivo. Additional studies showed that miR-133a can target the 3' untranslated region (3'UTR) of LIM and SH3 protein 1 (LASP1) mRNA and suppress the expression of LASP1, which we identified in previous studies as a CRC-associated protein. In contrast to the phenotypes induced by miR-133a restoration, LASP1-induced cell proliferation and migration rescued miR-133a-mediated biological behaviours, as did LASP1 overexpression. Investigations of possible mechanisms underlying these behaviours revealed that miR-133a modulates the expression of key cellular molecules and participates in the MAPK pathway by inhibiting phosphorylation of ERK and MEK. miR-133a may play a key role in CRC genesis and metastasis, which suggests its potential role in the molecular therapy of cancer.

Multi-therapeutic effects of human adipose-derived mesenchymal stem cells on radiation-induced intestinal injury

Radiation-induced intestinal injuries (RIII) commonly occur in patients who suffer from pelvic or abdominal cancer. However, current management of these injuries is ineffective. Recently, mesenchymal stem cells (MSCs) have been extensively used in regenerative medicine and have achieved a high level of efficacy. In the present study, we hypothesised that human adipose-derived mesenchymal stem cells (hAd-MSCs) could be used as potential tools to heal RIII. We observed that adult Sprague-Dawley rats that received whole-abdominal irradiation benefitted from hAd-MSC injection. hAd-MSCs had RIII-healing effects, including anti-inflammation, neovascularisation and maintenance of epithelium homeostasis, as indicated by elevated serum IL-10, upregulation of vascular endothelial growth factor, basic fibroblast growth factor and epidermal growth factor in irradiated intestine, mobilisation of CD31-positive haematopoietic stem cells or haematopoietic progenitor cells, and the prolonged presence of Bmi1-positive cells within crypts. Consequently, after hAd-MSC treatment, irradiated rats survived longer than non-treated animals. These results suggest that hAd-MSCs have therapeutic potential for RIII management.

A novel allele, HLA-A*03:01:09, identified by sequence-based typing in a Chinese individual

We describe the identification of a novel allele HLA-A*03:01:09 in a Chinese individual.

High expression of heat shock protein 90 is associated with tumor aggressiveness and poor prognosis in patients with advanced gastric cancer

The heat shock protein 90 (HSP90) is overexpressed and highly associated with poor prognosis in many malignancies. However, the role of HSP90 in gastric cancer has not been thoroughly elucidated. The aim of this study is to investigate the relationship of HSP90 expression with clinicopathological parameters and prognosis in advanced gastric cancer, and estimate the alteration of HSP90 expression after neoadjuvant chemotherapy. HSP90 and matrix metallopeptidase 9 (MMP-9) antigen expression was evaluated by immunohistochemistry in 322 advanced gastric carcinoma samples. The relationships between HSP90 and clinicopathological parameters and prognosis were analyzed. The response of HSP90 level was assessed in chemotherapeutic effect in 54 patients received 1-2 cycles of neoadjuvant chemotherapy. The positive expression of HSP90 was found to be 69.6% in 322 advanced gastric carcinoma samples. HSP90 protein expression was significantly associated with depth invasion (P<0.001), lymph node metastasis (P<0.001) and stage of disease (P<0.001). The positive rates of HSP90 expression were higher in both prominent serosal invasion group (P<0.001) and lymph node metastasis group (P<0.001). Moreover, HSP90 was significantly correlated with MMP-9 among 322 gastric cancer tissues (P<0.001). In univariate and multivariate analyses, HSP90 was an independent prognostic factor for both recurrence-free survival (RFS) and overall survival (OS). These results suggested that HSP90 may play an important role on tumor invasion, metastasis and prognosis, and might act as a promising target for prognostic prediction.

A novel HLA-B allele, B*07:55, identified by sequence-based typing

The novel allele differs from HLA-B*07:02:01 by a single nucleotide substitution at position 538 in exon 3.

Identification of a novel HLA-A allele, A*24:128 in a Chinese individual

The novel HLA-A*24:128 shows one nucleotide change from HLA-A*24:02:01:01 in exon 2 at position 155 from A to G.

A novel HLA-B allele, B*13:18, identified by sequence-based typing

The B*13:18 allele differs from the most closely matching allele B*13:02:01 by one nucleotide substitution in exon 3, at position 539.

LIM and SH3 protein 1, a promoter of cell proliferation and migration, is a novel independent prognostic indicator in hepatocellular carcinoma

LIM and SH3 protein 1 (LASP-1) plays a significant role in the formation of several malignant tumours. However, the biological and clinical significances of LASP-1 in hepatocellular carcinoma (HCC) remain largely unknown. Using immunohistochemistry, we analysed LASP-1 expression in 144 clinicopathologically characterised HCC cases. Using gene and transfection and RNA interference, we investigated the effects of LASP-1 overexpression and depletion on tumour cellular behaviour in vitro. LASP-1 expression was detected in not only cytoplasm and but also nucleus of HCC and liver cells. The positive rates of both cytosolic and nuclear LASP-1 expression in HCC were higher than adjacent non-tumourous tissues. Statistical analysis showed that heterogeneous LASP-1 expression is associated with hepatitis B surface antigen (HBsAg) and serum alpha-fetoprotein (AFP) level of HCC patients. A significant trend was identified between cytosolic LASP-1 overexpression in HCC and worsening clinical prognosis. Multivariate survival analysis showed that cytosolic LASP-1 expression was recognised as an independent prognostic factor of patient's survival. In vitro study showed LASP-1 promoted cell proliferation and migration, and resulted in aggressive phenotypes of cancer cells. LASP-1 is a valuable marker of HCC progression. High cytosolic LASP-1 expression is associated with poor overall survival in HCC patients.

Bioinformatics analysis of two microarray gene-expression data sets to select lung adenocarcinoma marker genes

BACKGROUND

Lung adenocarcinoma (LAC) is the most frequent histologic type of lung cancer and rates of adenocarcinoma are increasing in most countries. Recently, several molecular markers have been identified to predict LAC. However, more prognostic makers and the underlying role of those makers are still imperative.

AIM

In this study, our objective was to identify a set of discriminating genes that can be used for characterization and prediction of response to LAC.

MATERIALS AND METHODS

Using the bioinformatics analysis method, we merged two LAC datasets-GSE2514 and GSE7670 to find novel target genes and pathways to explain the pathogenicity.

RESULTS

The results showed that EDNRB (endothelin receptor type B), ADRB2 (beta-adrenergic receptor), S1PR1 (sphingosine-1-phosphate receptor 1), P2RY14 (PsY purinoceptor 14), LEPR (leptin-receptor), GHR (growth hormone receptor), PPM1D (protein phosphatase-1D), and GADD45B (growth arrest and DNA-damage-inducible, beta) have high degrees in response to LAC. Additionally, EDNRB, ADRB2, S1PR1, P2RY14, LEPR, and GHR may be involved in LAC through Neuroactive ligand-receptor interaction, but PPM1D and GADD45B may be through p53 signaling pathway. Some of our prediction had been demonstrated by previous reports, such as ADRB2, S1PR1, GHR, PPM1D, and GADD45B. Therefore, we hope our study could lay a basis for further study of other target genes, such as EDNRB, P2RY14, and LEPR.

CONCLUSIONS

It is effective to identify potential molecular marker for LAC and predict their underlying functions by bioinformatics analysis and graph clustering method. However, further experiments are still indispensable to confirm our conclusion.

Cigarette smoking extract causes hypermethylation and inactivation of WWOX gene in T-24 human bladder cancer cells

Genomic, epigenetic and expression alterations of WW domain containing oxidoreductase (WWOX) have been implicated in multiple tumor types. The current study was designed to examine the expression of WWOX in tumor tissues of human bladder transitional cell carcinoma (BTCC) and the influence of cigarette smoke extract (CSE) on WWOX expression and methylation status in T-24 bladder cancer cells. WWOX protein expression was evaluated by immunohistochemistry staining in a series of tumor samples from 78 patients with BTCC and 26 normal bladder tissues. The expression level and methylation status of WWOX in CSE-treated cells were examined by using quantitative Real-Time RT-PCR and methylation specific PCR, respectively. The expression levels of DNA methyltransferases (DNMTs) 1, 3A and 3B were also detected. We found that WWOX expression was absent or reduced in 79.5% (62/78) of BTCC tissues, but only in 19.2% (5/26) of normal bladder tissues. Loss of WWOX expression was correlated with tumor grade (P=0.019) and cigarette smoking (P=0.031), but was not associated with age, gender, tumor size and tumor number. Hypermethylation of WWOX promoter and exon 1 was specifically induced by CSE with a kinetics concurrent to the suppression of WWOX mRNA in T-24 cells. Furthermore, CSE treatment induced a significant time-dependent increase in the level of DNMT1, but has no effects on DNMT3A and DNMT3B. Taken together, these novel findings suggest that hypermethylation of WWOX induced by cigarette smoking may represent one underlying mechanism for the loss expression of WWOX in bladder cancer.

B ultrasound-guided hyperthermic intraperitoneal perfusion chemotherapy for the treatment of malignant ascites

To minimize invasive surgery, we employed B ultrasound to guide the placement of the catheters used in continuous circulatory hyperthermic intraperitoneal perfusion chemotherapy (CHIPC) in malignant ascites treatment. Thirty-two patients with malignant ascites were treated with CHIPC guided by B-mode ultrasound. Ascites were originally from ovarian cancer (11 cases), gastric cancer (10 cases), colorectal cancer (9 cases) and pancreatic cancer (2 cases). The CHIPC was carried out at 43˚C for 90 min with 0.9% saline solution as a carrier containing cisplatin and doxorubicin or mitomycin-C as therapeutic reagents depending on the type of the primary tumor. The therapeutic efficacy, postoperative complications and survival period of these patients were assessed with follow-up examinations. Among all participates to be assessed with ascites, 26 and 4 patients showed complete remission (CR) and partial remission (PR) respectively, with an objective remission rate (ORR) of 93.75%. The KPS scores were elevated by 23.1±9.0 after 3 sessions of ultrasound guided CHIPC and the quality of life (QOF) of patients was significantly improved (p<0.01). The median survival time was 9 months and 18 patients survived between 3 and 30 months after CHIPC treatment. Additionally, patients with different types of cancers significantly differed in the survival time (p<0.01). A novel approach of using B ultrasound guided CHIPC for the treatment of malignant ascites demonstrated satisfactory outcomes. The approach shows benefit in minimizing invasive surgery, improving the patient QOF and prolonging survival time.

Peer relationships and suicide ideation and attempts among Chinese adolescents

BACKGROUND

Suicide is a global health concern. Therefore, studying suicide behaviour and identifying the early roots of suicide are critical. To address these issues, the present study examined (i) the association between peer relationships and suicide ideation and attempts among Chinese adolescents; and (ii) whether such associations were moderated or mediated by feeling of loneliness. We hypothesized that problems in peer relationships were positively associated with suicide ideation and attempts, and that feeling of loneliness would moderate and mediate such associations.

METHODS

The sample included 8778 Chinese adolescents from a large survey. Measures of peer relationships, suicide ideation and attempts, and feeling of loneliness were obtained through adolescents' self-reports.

RESULTS

Results from multivariate logistic regressions suggested that specific problems in peer relationships, such as lack of peer association and being victimized by bullying, were significantly related to suicide ideation and attempts. In addition, the moderating effects of feeling of loneliness on the association between peer relationships and suicide ideation and attempts were found. Finally, some gender effects were also found.

CONCLUSIONS

The present study provided strong evidence that suicide ideation and attempts were serious problems among adolescents in China, to which peer relationships played an important role. Further, feeling of loneliness acted as a moderator affecting the association between peer relationships and suicide ideation and attempts. Finally, there were some gender differences that have important implications.

A 5-week study of the pharmacokinetics and pharmacodynamics of LY2189265, a novel, long-acting glucagon-like peptide-1 analogue, in patients with type 2 diabetes

AIM

To investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of LY2189265 (LY), a novel, long-acting glucagen-like peptide-1 analogue, administered once weekly to subjects with type 2 diabetes.

METHODS

This was a placebo-controlled, parallel-group, subject- and investigator-blind study of LY in subjects (N = 43) with type 2 diabetes mellitus controlled with diet and exercise alone or with a single oral antidiabetic medication. Subjects taking metformin or thiazolidinediones continued on their therapy. Subjects receiving sulfonylurea, acarbose, repaglinide or nateglinide were switched to metformin prior to enrollment. Subjects received five once-weekly doses of 0.05, 0.3, 1, 3, 5 or 8 mg. Effects on glucose, insulin and C-peptide concentrations were determined during fasting and following standard test meals. The pharmacokinetics of LY and its effects on HBA1c, glucagon, body weight, gastric emptying and safety parameters were assessed.

RESULTS

Once-weekly administration of LY significantly reduced (p < 0.01) fasting plasma glucose, 2-h post-test meal postprandial glucose and area under the curve (AUC) of glucose after test meals at doses ≥1 mg. These effects were seen after the first dose and were sustained through the weekly dosing cycle. Most doses produced statistically significant increases in insulin and C-peptide AUC when normalized for glucose AUC. Statistically significant reductions in HBA1c were observed for all dose groups except 0.3 mg. The most commonly reported adverse effects (AEs) were nausea (35 events), headache (20 events), vomiting (18 events) and diarrhoea (8 events).

CONCLUSIONS

LY showed improvement in fasting and postprandial glycaemic parameters when administered once weekly in subjects with type 2 diabetes. The pharmacokinetics and safety profiles also support further investigation of this novel agent.

MTBP plays a crucial role in mitotic progression and chromosome segregation

Murine double minute 2 (MDM2) binding protein (MTBP) has been implicated in tumor cell proliferation, but the underlying mechanisms remain unclear. The results of MTBP expression analysis during cell cycle progression demonstrated that MTBP protein was rapidly degraded during mitosis. Immunofluorescence studies revealed that a portion of MTBP was localized at the kinetochores during prometaphase. MTBP overexpression delayed mitotic progression from nuclear envelope breakdown (NEB) to anaphase onset and induced abnormal chromosome segregation such as lagging chromosomes, chromosome bridges, and multipolar chromosome segregation. Conversely, MTBP downmodulation caused an abbreviated metaphase and insufficient mitotic arrest, resulting in abnormal chromosome segregation, aneuploidy, decreased cell proliferation, senescence, and cell death, similar to that of Mad2 (mitotic arrest-deficient 2) downmodulation. Furthermore, MTBP downmodulation inhibited the accumulation of Mad1 and Mad2, but not BubR1 (budding uninhibited by benzimidazoles related 1), on the kinetochores, whereas MTBP overexpression inhibited the release of Mad2 from the metaphase kinetochores. These results may imply that MTBP has an important role in recruiting and/or retaining the Mad1/Mad2 complex at the kinetochores during prometaphase, but its degradation is required for silencing the mitotic checkpoint. Together, this study indicates that MTBP has a crucial role in proper mitotic progression and faithful chromosome segregation, providing new insights into regulation of the mitotic checkpoint.

Basic public health services delivered in an urban community: a qualitative study

OBJECTIVES

To understand the advancements in and barriers to the implementation of measures to improve basic public health services in an urban Chinese community.

STUDY DESIGN

A qualitative study based on semi-structured interviews. Interviews were audio-taped, transcribed and analysed using thematic content analysis.

METHODS

In-depth interviews were undertaken with the directors of the management centres for community health services in 15 of the 18 districts in Beijing from December 2008 to February 2009. Content analysis of the data was completed in May 2009.

RESULTS

Fifteen types of free basic public health services had been delivered in Beijing. Some were supplied at a low level. An average of £2.38 per person per year was provided for inhabitants since 2008, but demand for funding far exceeded monies available. Teams consisting of general practitioners, community nurses and public health specialists delivered these services. The number of practitioners and their low levels of skill were insufficient to provide adequate services for community residents. Respondents gave recommendations of how to resolve the above problems.

CONCLUSIONS

In order to improve the delivery of basic public health services, it is necessary for Beijing Municipal Government to supply clear and detailed protocols, increase funding and increase the number of skilled practitioners in the community health services.

Identification of site(s) of insulin nitration by peroxynitrite and characterization of its structural change

Insulin nitration mediated by peroxynitrite (ONOO(-)) has been implicated in diabetes and diabetic cardiovascular complications. In this study, we identified the nitration sites of porcine insulin by infusion of ONOO(-) and quantified its secondary structural change. Insulin was cleaved with V8 protease to six peptides (four of them contained each tyrosine residue), then analyzed by HPLC-MS and further confirmed the nitration sites by HPLC-MS/MS. At low accumulated doses of peroxynitrite, the main products were two different mono-nitrated insulin species at Tyr-A19 and Tyr-B26 with Tyr-A19 being predominant as shown by peptide mapping. Also, the content of alpha-helix structure of insulin reduced to 22.9 % and random-coil structure increased to 30.2 % (compare with native insulin of 41.7 % and 13.7 %, respectively) as determined by FTIR spectra.

Novel immunocontraceptive targets in mammals: uterine secretions and the conceptus; a marsupial approach

We report the first immunocontraceptive trial in mammals using a uterine-secreted protein, the marsupial shell coat protein 4 (CP4). The marsupial shell coat, which surrounds the conceptus for 60–80% of gestation, is secreted by the uterine epithelium. Following immunization against glutathione S-transferase (GST)-CP4, the fertility of female common brushtail possums (n=6) was significantly reduced (P=0.000), and this reduction in fertility was positively correlated with the maximum GST-CP4 humoral immune response (P=0.025). Ultrastructural examination of the reproductive tract indicated that the cell-mediated immune response against GST-CP4 targeted the shell coat, the shell-free conceptus and the uterine glandular epithelium, thus preventing normal conceptus development and uterine secretion of shell coat proteins and nutrients. These results show that uterine-secreted proteins are promising immunocontraceptive targets, especially in pest mammal species, e.g. possum, rabbit and horse, that have uterine-secreted additions to embryonic coats, or that have late implantation requiring uterine nutrient provisioning from secretions.

Vesicle-associated protein 1: a novel ovarian immunocontraceptive target in the common brushtail possum, Trichosurus vulpecula

Ovarian-based immunological research is currently restricted to proteins of the zona pellucida. This study examined the immunocontraceptive potential of a novel vesicle-associated protein, VAP1, previously isolated from the vesicle-rich hemisphere of the brushtail possum oocyte. Seven female possums were immunized against recombinant glutathione S-transferase-VAP1 fusion protein. Control animals (n=3) received antigen-free vaccinations. Following immunization, regular blood sampling determined the level and duration of immune response. Animals were monitored daily, pre- and post-immunization, to determine estrous cycling activity and the percentage of reproductive cycles yielding viable young. The reproductive tracts and somatic organs of VAP1-immunized (n=7), control-immunized (n=3) and non-immunized (n=5) animals were collected and examined by histology and transmission electron microscopy. VAP1 immunization caused a strong and sustained immune response. Elevated levels of VAP1 antibody binding were detected in sera following initial injections, and immune titers rose as boosters were administered. Immunization had no adverse effect upon animal behavior or body condition. Immunized females demonstrated no major change in annual estrous cycling activity; however, the percentage of reproductive cycles resulting in pouch young decreased significantly (P<0.05) by 40%. Histological and ultrastructural analyses revealed an abundance of lipid-like degradation bodies within the ooplasm of developing oocytes and the cytoplasm of failing uterine zygotes. Active macrophage invasion of enlarged endometrial glands was observed in the uteri of two females. Reproductive tract changes are discussed in relation to observed fertility decline. The results of this study indicate that VAP1 has exciting potential as an immunocontraceptive target for possum control in New Zealand.

In vitro assessment of antimicrobial activity of carvacrol, thymol and cinnamaldehyde towards Salmonella serotype Typhimurium DT104: effects of pig diets and emulsification in hydrocolloids

AIMS

To determine the effect of pig diets in vitro on the antimicrobial activity of carvacrol, thymol and cinnamaldehyde, and to identify an emulsifier/stabilizer that can stabilize the essential oil (EO) components in aqueous solution and retain their antimicrobial activity in the presence of the diets.

METHODS AND RESULTS

Emulsification of essential oil components with hydrocolloid solution was achieved by blending with a Polytron. Antimicrobial activity was measured through in vitro assays to determine the inhibition of bacterial growth by measuring the optical density at 600 nm or plating on nutrition agar after incubation of the mixtures of an EO component with the culture of Salmonella serotype Typhimurium DT104 in the presence or absence of pig diets. The results generated through the in vitro assays indicated that pig diets were able to abolish the antimicrobial activity of EOs. Xanthan, fenugreek and yellow mustard gums were the best in forming stable emulsions of five different EO components among ten different plant polysaccharides and surfactants examined. Emulsification of all the EO components in the fenugreek gum solution did not alter their antimicrobial activity. However, the antimicrobial activity of geraniol was significantly reduced when emulsified with other polysaccharides and surfactants. Both fenugreek and xanthan gum solutions were unable to protect the antimicrobial activity of carvacrol and thymol when mixed with the diets. Although cinnamaldehyde required no emulsification, but a high concentration (equivalent to at least three times of minimum bactericidal concentration for cinnamon oil) to inhibit Salmonella growth significantly in the presence of the diets, emulsification in fenugreek gum appeared to be essential for cinnamaldehyde solution to retain its antimicrobial activity during storage.

CONCLUSIONS

The diets for newly weaned pigs were a significant factor limiting the antimicrobial activity of EOs and their components. Cinnamaldehyde required a high concentration to retain its antimicrobial activity in the diets, in addition to its requirement for emulsification to stabilize its activity during the storage.

SIGNIFICANCE AND IMPACT OF THE STUDY

The assay with the diets used in this study for measuring the antimicrobial activity can be used in vitro for rapid and effective screening of potential antimicrobials for swine production. This study has identified polysaccharides that are able to stabilize EO component solutions. It has also identified cinnamaldehyde for further in vivo studies that may have potential in future application in controlling Salmonella and possibly other enteric pathogens in swine production.

MicroRNAs that underlie response to salvage chemotherapy in ovarian cancer

10542

Background: MicroRNAs (miRNAs) are non-protein coding, endogenous, small RNAs that can bind complementary mRNA to modulate gene expression and protein translation. Recent studies indicate that miRNAs may be mechanistically involved in ovarian cancer chemosensitivity and may play an important role in the development of chemoresistance. The objective of the current study was to explore the role of miRNAs in the response of platinum-resistant recurrent or persistent ovarian cancer to salvage chemotherapy. Methods: MicroRNA was extracted from 16 ovarian cancer cell lines. All samples were hybridized to a miRNA array that contained Ambion and Invitrogen probe sets. In parallel, the 16 ovarian cancer cell lines were treated with Doxorubicin, Topotecan, Paclitaxel, Docetaxel, and Gemcitabine, and their response to treatment evaluated using proliferation assays. Logistic regression analysis was used to identify miRNAs associated with responsiveness to individual chemotherapeutic agents. Results: Linear regression analysis identified a total of 39 miRNAs significantly associated with salvage chemotherapy responsiveness. Sixteen miRNAs were associated with response to Doxorubicin, 18 associated with response to Topotecan, 2 associated with response to Docetaxel, 9 associated with response to Paclitaxel, and 11 associated with response to Gemcitabine (p<0.05). Ten miRNAs were associated with more than one chemotherapy (miR-126, miR-199a, miR-202 [Doxorubicin, Topotecan, Gemcitabine], miR-26a, miR-320 [Doxorubicin, Topotecan], miR-181b [Doxorubicin, Topotecan, Paclitaxel], 181a [Topotecan, Gemcitabine, Adriamycin, Paclitaxel], miR-99b [Doxorubicin, Paclitaxel, Docetaxel], miR-31 [Docetaxel, Paclitaxel], miR-339 [Doxorubicin, Gemcitabine]). Conclusion: We have identified miRNAs that may influence ovarian cancer responsiveness to salvage chemotherapy. Ten of the miRNAs were associated with chemosensitivity to more than one drug. These miRNAs may regulate common determinants of chemoresistance and may also serve as novel therapeutic targets for patients with chemoresistant ovarian cancer. Further studies are warranted to validate these results.

No significant financial relationships to disclose.

Hepatic pre-sinusoidal vessels contract in anaphylactic hypotension in rabbits

AIM

The purpose of this study was to determine whether anaphylactic hypotension in rabbits is accompanied by hepatic venoconstriction, and the effects of anaphylaxis on hepatic segmental vascular resistances and liver weight in isolated perfused rabbit livers.

METHODS

The rabbits were sensitized by subcutaneous injection of antigen of 2.5 mg ovalbumin with complete Freund's adjuvant three times at 1 week interval. One week after sensitization, anaphylaxis was induced by an injection of 2.5 mg ovalbumin into the jugular vein of pentobarbital anaesthetized rabbits or the perfusate of rabbit livers perfused via the portal vein at a constant flow. Using the double occlusion technique to estimate the hepatic sinusoidal pressure, pre- (R(pre)) and post-sinusoidal (R(post)) resistances were calculated for the isolated perfused livers.

RESULTS

An antigen injection into the sensitized rabbits caused not only a decrease in systemic arterial pressure from 79 +/- 2 to 40 +/- 4 mmHg, but also an increase in portal venous pressure (P(pv)) from 9.5 +/- 2.2 to 24.1 +/- 3.9 cmH(2)O. Portal hypertension persisted for 8 min after the antigen injection. An injection of antigen into the perfusate caused a marked increase in P(pv) from 5.4 +/- 0.1 to 28.6 +/- 2.4 cmH(2)O at 6 min, but only a slight increase in double occlusion pressure from 2.2 +/- 0.2 to 3.8 +/- 0.2 cmH(2)O, resulting in a selective increase in R(pret) rather than R(post). Concomitant with the hepatic pre-sinusoidal constriction, liver weight loss occurred.

CONCLUSION

Anaphylactic hypotension in rabbits is accompanied by hepatic venoconstriction which is characterized by pre-sinusoidal contraction.