Meta-analysis: polymorphisms in TNF-alpha gene promoter and Crohn's disease

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) is involved in the pathogenesis of Crohn's disease (CD). However, results on the association between the polymorphisms in TNF-alpha promoter and the risk of CD are inconsistent.

AIM

To perform a quantitative synthesis for the genetic polymorphisms in TNF-alpha promoter and CD risk.

METHODS

Databases were searched (up to 2009) and 31 studies were included. Risks of CD associated with the polymorphisms in TNF-alpha promoter were assessed.

RESULTS

Overall, individuals with -1031 TC+CC genotype had a slightly increased risk to develop CD compared with individuals with -1031 TT genotype (OR, 1.32; 95% CI, 1.03-1.70). In the further stratified analysis, we found Asians with the -1031T>C, -863 C>A and -857 C>T variant polymorphisms have almost one and a half CD risk compared with other genotypes (OR, 1.58; 95% CI, 1.16-2.15; OR, 1.55; 95% CI, 1.18-2.02; OR, 1.54; 95% CI, 1.19-1.99 respectively). We did not find -308 G>A variant associated with CD location and disease behaviours in stratified analysis.

CONCLUSIONS

TNF-alpha polymorphisms in the promoter region might be used as a biomarker for CD risk prediction. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Manufacturing of 50 kA superconducting transformer for ITER correction coil conductor test

To meet the specifications of International Thermonuclear Experimental Reactor correction coil (CC) conductor, a 50 kA superconducting transformer has been designed and manufactured to provide the short sample of the CC conductor the current. The transformer consists of two concentric layer-wound superconducting solenoids with the primary inside the secondary coil. In order to test the transformer, the two legs of the secondary coil were directly connected by superconducting cables. A 500 W/4.5 K refrigerator was used to provide the supercritical helium. The maximum current of 56.3 kA in the secondary coil loop was obtained.

The rag locus of Porphyromonas gingivalis might arise from Bacteroides via horizontal gene transfer

Porphyromonas gingivalis is regarded as one of the risk factors of periodontitis. P. gingivalis exhibits a wide variety of genotypes. Many insertion sequences (ISs), located in their chromosomes, made P. gingivalis differentiate into virulent and avirulent strains. In this research, we investigated the prevalence of P. gingivalis in the gingival crevicular fluid (GCF) among periodontitis patients from Zhenjiang, China, detected the P. gingivalis rag locus distributions by multiplex polymerase chain reaction (PCR), and analyzed the origin of the P. gingivalis rag locus based on evolution. There were three rag locus variants co-existing in Zhenjiang. The results showed that the rag locus may be associated with severe periodontitis. This work also firstly ascertained that the rag locus might arise, in theory, from Bacteroides sp. via horizontal gene transfer.

Single-center experience of 253 portal vein thrombosis patients undergoing liver transplantation in China

OBJECTIVE

We sought to review the etiopathogenesis, diagnosis, and surgical options for 253 patients with portal vein thrombosis (PVT) undergoing orthotopic liver transplantation (OLT) to assess the the impact of PVT on outcomes.

METHODS

We retrospectively analyzed the data from 2508 adult patients undergoing 2614 OLTs in our center from September 1998 to July 2007. PVT was scored according to the operative findings and Yerdel grading of PVT. No prisoners were used as donors for this study.

RESULTS

Two hundred fifty-three patients were diagnosed with PVT (10.09%): there were 104 grade I; 114, grade II; 29, grade III; and 6, grade IV PVT. Sex and previous splenectomy increased the risk for PVT. In grade I and II cases, we performed simple thrombectomy, eversion thrombectomy, or improved eversion thrombectomy (IET, innovated by our center), producing smooth postoperative recoveries with a 0% in-hospitality mortality. In grade III cases, 18 underwent successful IET. Of 11 subjects who had eversion thrombectomy, six failed, and the distal superior mesentery vein or dilated splanchnic collateral tributary had to be used as the inflow vessel in four patients, and portal vein arterialization were performed in the other two patients, all of whom experienced a smooth postoperative recovery except one who died of hepatic failure and pulmonary infection 2 weeks after the operation. The in-hospitality mortality was 3.45%. In grade IV cases, three underwent successful IET, but another three cases failed, with two of them requiring a renal vein as the inflow vessel, and other one undergoing portocaval hemitransposition, with one postoperative death due to hepatic failure and another of cancer recurrence, an in-hospitality mortality rate of 33.33%. The transfusion requirement among PVT patients was significantly higher than that in non-PVT patients (9.32 +/- 3.12 U vs 6.02 +/- 2.40 U; P < .01). Blood loss in PVT patients who underwent the IET technique was significantly lower than that for an eversion thrombectomy (2800.36 +/- 930.52 mL vs 5700.21 +/- 162.50 mL P < .05). The overall actuarial 1-year survival rate in PVT patients was similar to the controls (86.56% vs 89.40%; P > .05).

CONCLUSION

OLT was successfully performed for PVT patients. The grade of PVT decided the surgical strategy. Similar 1-year survival rates were attained between PVT patients and controls undergoing OLT.

Four types of potassium currents in motor nerve terminals of snake

The experiments were performed on transversus abdominis muscle of Elaphe dione by subendothelial recording. The results indicate that in snake motor nerve endings there exist four types of K(+) channels, i.e. voltage-dependent fast and slow K(+) channels, Ca(2+)-activated K(+) channel and ATP-sensitive K(+) channel. (i) The typical wave form of snake terminal current was the double-peaked negativity in standard solution. The first peak was attributed to Na(+) influx (I(Na)) in nodes of Ranvier. The second one was blocked by 3,4-aminopyridine (3,4-DAP) or tetraethylammonium (TEA), which corresponded to fast K(+) outward current (I(k.f)) through the fast K(+) channels in terminal part. (ii) After I(K.F) as well as the slow K(+) current (I(K.S)) were blocked by 3, 4-DAP, the TEA-sensitive Ca(2 +)-dependent K(+) current (I(K(Ca))) passing through Ca(2 +)-activated K(+) channel was revealed, whose amplitude depended on [K(+)](o) and [ca(2+) ](o). It was blocked by Ba(2+), Cd(2+) or Co(2+). (iii) I(K.F) and I(K(Ca)) were blocked by TEA, while I(K. S) was retained. It was sensitive to 3,4-DAP, partially blocked by ethanol (200 mmol/L) or beta-bungarotoxin (2 micromol/L), and enhanced by low pH (6.4-6.7). This is the first report that certain current component of motor nerve terminal is sensitive to pH in the range of 6. 4-7. 5. (iv) That diazoxide (200 micromol/L) increased the second negative peak and the effect was eliminated after further addition of glibenclamide (50 micromol/L) was taken as evidence for the presence of ATP-sensitive K(+) current (I(K.ATP)) at snake nerve terminal.

Peroxynitrite mediates glomerular lesion of diabetic rat via JAK/STAT signaling pathway

BACKGROUND

Peroxynitrite, a highly reactive oxidant produced by the reaction of nitric oxide with free radicals superoxide, has been indicated to be involved in many diseases. However, the contributions of peroxynitrite to diabetic nephropathy and the underlying mechanism have not been fully explored.

AIM

The present study was designed to evaluate the role and the underlying mechanism of peroxynitrite in glomerular lesion of diabetic rat.

METHODS

Diabetes was induced in male Wistar rats by i.p. injection of streptozotocin, and urate was used as a specific scavenger of peroxynitrite; the pathological changes of rat glomerulus were evaluated by hematoxylin and eosin, periodic acid-Schiff staining and transmission electron microscopy observation; immunohistochemistry and Western blot were used to detect the content of nitrotyrosine (the marker of peroxynitrite) in renal cortex; the expression levels of tyrosine phosphorylation of JAK2, STAT1, and STAT3 were assessed by Western blot assay; RT-PCR and Western blot were used to assay expression levels of transforming growth factor (TGF)-beta1 and fibronectin; biochemical indicators of renal function were also detected.

RESULTS

The content of nitrotyrosine was increased, consistent with the pathological changes of glomerulus and renal dysfunction in the diabetes group. Urate prevented the formation of nitrotyrosine in rat glomerulus and attenuated the pathological alterations. Furthermore, urate inhibited the activation of JAK2, STAT1, and STAT3. Finally, homogenates from renal cortices demonstrated reduced expression of TGF- beta1 and fibronectin under urate treatment.

CONCLUSIONS

Our findings thus provides in vivo evidence that exaggerated peroxynitrite formation mediates the glomerular lesion in, at least, Type 1 diabetes, which may function through JAK/STAT signaling pathway.

Critical role of TRPC6 channels in G2 phase transition and the development of human oesophageal cancer

BACKGROUND

Oesophageal squamous cell carcinoma (OSCC) is one of the leading causes of cancer-related death worldwide. However, the mechanism by which the OSCC develops remains largely unknown. Ion channels are important for cancer development. Whether the transient receptor potential canonical (TRPC), known as the non-selective cation channels, plays a role in OSCC development is unknown.

METHODS

The expression of TRPC6, a member of TRPC subfamily, was examined in samples from patients with OSCC by immunostaining and in situ hybridisation. The effects of TRPC6 channels on OSCC cell cycle progression, cell growth and in vivo tumour formation were investigated. The functional TRPC6 channels were found in OSCC cells by electrophysiology and Ca(2+) imaging analysis.

RESULTS

The expression of TRPC6 at protein and mRNA levels was markedly increased in human OSCC specimens than that in normal human oesophageal tissues. Blockade of TRPC6 channels in human OSCC cells inhibited elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) and activation of Cdc2 kinase. Meanwhile, the OSCC cell cycle was arrested at G2 phase and the cell growth was suppressed. Furthermore, inhibition of TRPC6 channels suppressed in nude mice the tumour formation generated by injection of the OSCC cells.

CONCLUSION

TRPC6 channels play a critical role in the development of OSCC. The [Ca(2+)](i) elevation regulated by TRPC6 channels is essential for G2 phase progression and OSCC development. These channels might be a novel target for therapeutic intervention of OSCC.

High mobility group box 1 as a mediator of endotoxin administration after hemorrhagic shock-primed lung injury

High mobility group box 1 (HMGB1) was discovered as a novel late-acting cytokine that contributes to acute lung injury (ALI). However, the contribution of HMGB1 to two-hit-induced ALI has not been investigated. To examine the participation of HMGB1 in the pathogenesis of ALI caused by the two-hit hypothesis, endotoxin was injected intratracheally in a hemorrhagic shock-primed ALI mouse model. Concentrations of HMGB1 in the lung of the shock group were markedly increased at 16 h (1.63 +/- 0.05, compared to the control group: 1.02 +/- 0.03; P < 0.05), with the highest concentration being observed at 24 h. In the sham/lipopolysaccharide group, lung HMGB1 concentrations were found to be markedly increased at 24 h (1.98 +/- 0.08, compared to the control group: 1.07 +/- 0.03; P < 0.05). Administration of lipopolysaccharide to the hemorrhagic shock group resulted in a notable HMGB1 increase by 4 h, with a further increase by 16 h. Intratracheal lipopolysaccharide injection after hemorrhagic shock resulted in the highest lung leak at 16 h (2.68 +/- 0.08, compared to the control group: 1.05 +/- 0.04; P < 0.05). Compared to the hemorrhagic shock/lipopolysaccharide mice, blockade of HMGB1 at the same time as lipopolysaccharide injection prevented significantly pulmonary tumor necrosis factor-alpha, interleukin-1beta and myeloperoxidase. Lung leak was also markedly reduced at 16 h; blockade of HMGB1 24 h after lipopolysaccharide injection failed to alter lung leak or myeloperoxidase at 48 h. Our observations suggest that HMGB1 plays a key role as a late mediator when lipopolysaccharide is injected after hemorrhagic shock-primed ALI and the kinetics of its release differs from that of one-hit ALI. The therapeutic window to suppress HMGB1 activity should not be delayed to 24 h after the disease onset.

Prolonging microtubule dysruption enhances the immunogenicity of chronic lymphocytic leukaemia cells

Cytotoxic chemotherapies do not usually mediate the expression of an immunogenic gene programme in tumours, despite activating many of the signalling pathways employed by highly immunogenic cells. Concomitant use of agents that modulate and complement stress-signalling pathways activated by chemotherapeutic agents may then enhance the immunogenicity of cancer cells, increase their susceptibility to T cell-mediated controls and lead to higher clinical remission rates. Consistent with this hypothesis, the microtubule inhibitor, vincristine, caused chronic lymphocytic leukaemia (CLL) cells to die rapidly, without increasing their immunogenicity. Protein kinase C (PKC) agonists (such as bryostatin) delayed the death of vincristine-treated CLL cells and made them highly immunogenic, with increased stimulatory abilities in mixed lymphocyte responses, production of proinflammatory cytokines, expression of co-stimulatory molecules and activation of c-Jun N-terminal kinase (JNK), p38 and nuclear factor kappa B (NF-kappaB) signalling pathways. This phenotype was similar to the result of activating CLL cells through Toll-like receptors (TLRs), which communicate 'danger' signals from infectious pathogens. Use of PKC agonists and microtubule inhibitors to mimic TLR-signalling, and increase the immunogenicity of CLL cells, has implications for the design of chemo-immunotherapeutic strategies.