Experimental and molecular dynamics investigation on tribological properties of nanocrystalline diamond films

Nanocrystalline diamond films were deposited on cemented tungsten carbide substrates using hot filament chemical vapor deposition (HFCVD) method, and their tribological properties were investigated by friction experiments and classical molecular dynamics simulations. The friction tests were performed on a ball-on-plate type reciprocating friction tester under various normal loads and sliding velocities conditions; the experimental results suggested that the friction coefficient of diamond films showed increasing tendency with the growing normal load and sliding velocity. Furthermore, classical molecular dynamics simulations were conducted to investigate the changes in atomic scale friction behaviors of diamond films under extremely high normal load and sliding velocity conditions, the atomistic sliding mechanism was also discussed in this study.

Intensive glycemic control lowers plasma visfatin levels in patients with type 2 diabetes

Visfatin is an independent association factor for type 2 diabetes mellitus (T2DM). In order to evaluate the plasma visfatin levels and investigate whether plasma visfatin concentrations are altered by intensive glycemic control in patients with diabetes, we determined plasma visfatin concentrations and metabolic parameters in 53 newly diagnosed type 2 diabetic patients and 35 healthy controls. Visfatin levels were also investigated before and after intensive glycemic control for three months in subgroup of patients with T2DM. Plasma visfatin levels were significantly elevated in diabetic patients compared with healthy controls (p<0.001). Circulating visfatin concentration was associated with fasting plasma glucose (FPG), 2-hour OGTT plasma glucose (2hPG), HOMA-beta indexes (r=0.338, p=0.001; r=0.340, p=0.002; r=-0.296, p=0.006, respectively), but not with insulin sensitivity (HOMA-IR) or other metabolic or anthropometric parameters in all subjects. In addition, visfatin levels were also correlated with HbA1c levels in diabetic patients. Furthermore, visfatin concentrations reduced from 25.0+/-6.5 ng/ml at baseline to 20.3+/-4.7 ng/ml (p<0.01) after 3 months of intensive glycemic control, while HbA1c levels decreased from 9.0+/-1.8% to 6.2+/-0.7% (p<0.01). We conclude that the change of visfatin concentration may be a compensatory mechanism to ameliorate insulin deficiency due to pancreatic beta-cell dysfunction.

The pathogenic role of interleukin-27 in autoimmune diabetes

Interleukin (IL)-27 is an IL-12-related cytokine that can promote both anti- and pro-inflammatory immune responses. This study investigated the potential role of IL-27 in autoimmune diabetes. We detected a high level of IL-27 in diabetic NOD mice. In addition, blockade of IL-27 significantly delayed the onset of diabetic splenocyte-transferred diabetes, while IL-27-treated diabetic splenocytes promoted the onset of the disease, compared with untreated controls. Furthermore, IL-27 up-regulated pro-inflammatory cytokines IFN-gamma and IL-17 and down-regulated anti-inflammatory cytokines IL-4, TGF-beta, and IL-10 secreted by diabetic splenocytes. These results demonstrate a pathogenic role of IL-27 in T cell-mediated autoimmune diabetes.

A new strategy to induce effective antitumour response in vitro and in vivo

To induce Her2-specific cell immune response, we used xenogeneic antigen rat neu L2-S2 domains as the vaccine antigen. The antigenic protein was engineered as a chimeric protein with human IgG1 Fc region (neu-Fc). Neu-Fc could stimulate the cell proliferation in mixed lymphocyte reaction effectively. Simultaneous neu-Fc and IFN-gamma stimulation dramatically elevated IL-12 secretion and reduced IL-10 production in PBMC. To further augment the activating effects on Th1-type response, Bacille Calmette-Guerin (BCG) was utilized as a non-specific stimulus. Neu-Fc, IFN-gamma and BCG costimulation exhibited the most conspicuous effects on the reversal of the Th1-type inhibitory effects by MCF-7 cell supernatant compared with neu-Fc alone or IFN-gamma and BCG costimulation. The lytic activity of effector cells to Her2 overexpressing cells was greatly promoted by neu-Fc, IFN-gamma and BCG stimulation simultaneously. Neu-Fc led to considerable retardation in EMT6/Her2 tumour growth in Balb/c mice. IFN-gamma and BCG efficiently enhanced the antitumour activity. A large amount of inflammatory cells were found to be accumulated in the tumour tissues or surrounded tumours in mice treated with neu-Fc, IFN-gamma and BCG but no inflammatory cell infiltration was observed in control tumours, indicating that the strategy is potent enough to support the initiation and propagation of tumour-specific immune response in an established tumour and generate a proinflammatory environment.

Anomalous photogalvanic effect of circularly polarized light incident on the two-dimensional electron gas in Al{x}Ga{1-x}N/GaN heterostructures at room temperature

Under normal incidence of circularly polarized light at room temperature, a charge current with swirly distribution has been observed in the two-dimensional electron gas in Al{0.25}Ga{0.75}N/GaN heterostructures. We believe that this anomalous charge current is produced by a radial spin current via the reciprocal spin Hall effect. It suggests a new way to research the reciprocal spin Hall effect and spin current on the macroscopic scale and at room temperature.

Overexpression, refolding, purification of Erbin PDZ domain from Escherichia coli and preparation of its polyclonal antibody

The Erbin was recently identified. The antibody against Erbin has not been commercially available. As a new member of peripheral protein LAP family and novel type of adaptor protein, its functions and binding partners are not completely known. In the present study, cDNA encoding PDZ domain of Erbin was inserted in a prokaryotic expression vector. His-tagged recombinant protein was overproduced in E. coli and purified by Ni-NTA column chromatography. About 14.4 mg of the purified protein was obtained from 500 mL of cell culture. The purity of the recombinant protein was higher than 90%. The polyclonal antibody against this protein was raised. The antibody can recognize both denatured and natural Erbin protein. It will be used to further identify the new binding partners of Erbin and study its unknown functions.

Endoscopy in the management of patients after ileal pouch surgery for ulcerative colitis

Pouchitis is the most common complication following ileal pouch-anal anastomosis in patients with ulcerative colitis. However, there are several other inflammatory and noninflammatory conditions that can mimic pouchitis, and endoscopy with biopsies is essential for distinguishing these various conditions. This paper will review the differential diagnosis of pouchitis and the role of endoscopy in the diagnosis and management of disorders of the ileal pouch.

Mechanisms underlying B-cell tolerance induction by antigen-immunoglobulin G gene transfer

Previous studies on the mechanisms underlying tolerance induction in diabetes have mainly focused on T cells, however B cells also have an important role in diabetes. Based on our previous studies that splenocytes, transduced with glutamic acid decarboxylase (GAD) 65 fused to immunoglobulin (Ig) G carrier, reduced antibody-mediated response in non-obese diabetic (NOD) mice, here we examined the mechanisms underlying B-cell tolerance in this system. We found that GAD-IgG-transduced splenocytes did not reduce CD40 expression on B-cells in NOD mice, but they did downregulate CD40 ligand (CD40L) expression. Furthermore, anti-CD40L injection reduced autoantibody levels in NOD mice and in vitro experiments demonstrated that CD40L blockade reduced the antigenpresenting capability of B-cells. In conclusion, the results of this study suggest that downregulation of CD40L may be one mechanism underlying the induction of B-cell tolerance in GAD-IgG-treated NOD mice.

Mechanisms of regulatory T-cell induction by antigen-IgG-transduced splenocytes

Our previous studies have demonstrated that splenocytes, transduced with glutamate decarboxylate 65 (GAD) and IgG fusion construct, protect non-obese diabetes (NOD) mice from diabetes. However, the mechanism by which this strategy prevents diabetes is not well understood. Here, we found that CD4(+)Foxp3(+)Treg cells, in vitro induced by GAD-IgG-transduced splenocytes, after transfer, were responsible for prevention of diabetes in NOD mice. Further studies suggested that GAD-IgG-transduced B cells could secrete high level of TGF-beta and stimulated CD4(+)T cells to secrete high level of IFN-gamma. Finally, we found that when TGF-beta and/or IFN-gamma were blocked, CD4(+)Foxp3(-)T cells were not converted into CD4(+)Foxp3(+)Treg cells. The results suggest that GAD-IgG-transduced B cells via TGF-beta and IFN-gamma in vitro induce the CD4(+)Foxp3(+)Treg cells which are responsible for prevention of diabetes in NOD mice by GAD-IgG-gene transfer.

Poloidal beta and internal inductance measurement on HT-7 superconducting tokamak

Poloidal beta beta(theta) and internal inductance l(i) measurements are very important for tokamak operation. Much more plasma parameters can be inferred from the two parameters, such as the plasma energy confinement time, the plasma toroidal current profile, and magnetohydrodynamics instability. Using diamagnetic and compensation loop, combining with poloidal magnetic probe array signals, poloidal beta beta(theta) and internal inductance l(i) are measured. In this article, the measurement system and arithmetic are introduced. Different experimental results are given in different plasma discharges on HT-7 superconducting tokamak.

Blockage of intermediate-conductance-Ca(2+) -activated K(+) channels inhibits progression of human endometrial cancer

Potassium (K(+)) channels have been implicated in proliferation of some tumor cells. However, whether K(+) channels are important to the pathogenesis of endometrial cancer (EC) remains unknown. In the present study, we report that intermediate-conductance Ca(2+)-activated K(+) (IKCa1) channels play a critical role in the development of EC. The expression of IKCa1 at both mRNA and protein levels in EC tissues was greatly increased than that in atypical hyperplasia and normal tissues. Treatment of EC cells with clotrimazole and TRAM-34, two agents known to inhibit IKCa1 channels, suppressed the proliferation of EC cells and blocked EC cell cycle at G(0)/G(1) phase. Similarly, downregulation of IKCa1 by siRNA against IKCa1 inhibited EC cell proliferation and arrested its cell cycle at G(0)/G(1) phase. A clotrimazole-sensitive K(+) current was induced in EC cells in response to the increased Ca(2+). The current density induced by Ca(2+) was greatly reduced by clotrimazole, TRAM-34, charybdotoxin or downregulation of IKCa1 by the siRNA against IKCa1. Furthermore, TRAM-34 and clotrimazole slowed the formation in nude mice of tumor generated by injection of EC cells. Our results suggest that increased activity of IKCa1 channel is necessary for the development of EC.

Catalyst-free synthesis of well-aligned ZnO nanowires on In0.2Ga0.8N, GaN, and Al0.25Ga0.75N substrates

Well-aligned ZnO nanowires have been synthesized vertically on In0.2Ga0.8N, GaN, and Al0.25Ga0.75N substrates, using a catalyst-free carbon thermal-reduction vapor phase deposition method for the first time. The as-synthesized nanowires are single crystalline wurtzite structure, and have a growth direction of [0001]. Each nanowire has a smooth surface, and uniform diameter along the growth direction. The average diameter and length of these nanowires are 120-150 nm, and 3-10 )m, respectively. We suggest that the growth mechanism follow a self-catalyzing growth model. Excitonic emission peaked around 385 nm dominates the room-temperature photoluminescence spectra of these nanowires. The room-temperature photoluminescence and Raman scattering spectra show that these nanowires have good optical quality with very less structural defects.

Collagenous pouchitis

Collagenous colitis is characterised by watery diarrhoea, normal colonic mucosa on endoscopy, diffuse colitis with surface epithelial injury, and a distinctive thickening of the subepithelial collagen table on histology. Some patients can develop medically refractory collagenous colitis, in which case they may require surgical intervention. This is the first report of collagenous pouchitis in a collagenous colitis patient with proctocolectomy and ileal pouch-anal anastomosis. A patient with medically refractory collagenous colitis who underwent a total proctocolectomy and ileal pouch-anal anastomosis was sequentially evaluated with an endoscopy and histology of the colon, distal small intestine, and ileal pouch. A 58-year-old female had a 10-year history of collagenous colitis before having a total proctocolectomy and ileal pouch-anal anastomosis for medically refractory disease. The histologic features of collagenous colitis were present in all colon and rectum biopsy or resection specimens, but were absent in the distal ileum specimen. The post-operative course was complicated by persistent increase of stool frequency, abdominal cramps, and incontinence. A pouch endoscopy was performed 3 years after ileal pouch-anal anastomosis which showed the histologic features of collagenous colitis in the ileal pouch, collagenous pouchitis, while the pre-pouch neo-terminal ileum had no pathologic changes. After antibiotic therapy, the histologic changes of collagenous pouchitis resolved. This is the first reported case of collagenous pouchitis. Since the abnormal collagen table and its associated features were only present in the pouch and absent in the neo-terminal ileum, and the patient had histologic improvement after antibiotic therapy, it would suggest that faecal stasis and bacterial load may play a role in the pathogenesis.

The heritability of the expression of two stress-regulated gene fragments in pigs

Pigs reared in commercial production units sometimes encounter stressors that significantly decrease growth performance. It is hypothesized that response to stress challenges could potentially be used as selection criteria. This study aimed to investigate, in a commercial setting, the heritability of two target genes previously shown to be induced in response to stress, and related to growth performance, in an experimental situation. Blood samples (n = 2,392) were collected from three separate breeding lines of pedigreed and performance-tested boars between 24 to 25 wk of age. The expression levels of a novel fragment, '29a,' and the calcitonin receptor gene (CTR) were quantified using quantitative real-time PCR (qRT-PCR) on a subset (n = 709) of the blood samples. Gene expression levels were corrected for the efficiency of PCR reactions and also computed directly from threshold cycle (Ct) values. Resulting data showed a skewed nonnormal distribution of expression levels for the target genes relative to the endogenous control, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and were highly variable. Analyses were subsequently performed using untransformed and log-transformed data, with outliers identified and deleted in edited data sets. Regardless of the transformation or editing procedures for outliers applied, there was negligible genetic variation for the expression of target genes relative to GAPDH. In contrast, repeatabilities of replicate samples were generally high (between 0.54 and 0.67). Absolute expression levels for GAPDH and 29a were lowly heritable (h2 of about 0.04), although estimates did not exceed their SE. Subsetting the data according to whether the target gene had a higher or lower level of expression than GAPDH was then performed using the relevant Ct values. In the subset where the target gene was more highly expressed than GAPDH, a moderate estimate of heritability (0.18 +/- 0.10) for the log-transformed absolute expression level of 29a was obtained, whereas the estimate for its expression relative to GAPDH was lower (0.09 +/- 0.07). Estimates of heritability did not increase in the subset of low expression data. The limitations of using gene expression measures as potential selection criteria in commercial situations are discussed.

Analysis of the human protein interactome and comparison with yeast, worm and fly interaction datasets

We present the first analysis of the human proteome with regard to interactions between proteins. We also compare the human interactome with the available interaction datasets from yeast (Saccharomyces cerevisiae), worm (Caenorhabditis elegans) and fly (Drosophila melanogaster). Of >70,000 binary interactions, only 42 were common to human, worm and fly, and only 16 were common to all four datasets. An additional 36 interactions were common to fly and worm but were not observed in humans, although a coimmunoprecipitation assay showed that 9 of the interactions do occur in humans. A re-examination of the connectivity of essential genes in yeast and humans indicated that the available data do not support the presumption that the number of interaction partners can accurately predict whether a gene is essential. Finally, we found that proteins encoded by genes mutated in inherited genetic disorders are likely to interact with proteins known to cause similar disorders, suggesting the existence of disease subnetworks. The human interaction map constructed from our analysis should facilitate an integrative systems biology approach to elucidating the cellular networks that contribute to health and disease states.

A 'Chinese Spring' wheat (Triticum aestivum L.) bacterial artificial chromosome library and its use in the isolation of SSR markers for targeted genome regions

A bacterial artificial chromosome (BAC) library was constructed from the bread wheat (Triticum aestivum L.) genotype 'Chinese Spring' ('CS'). The library consists of 395,136 clones with an estimated average insert size of 157 kb. This library provides an estimated 3.4-fold genome coverage for this hexaploid species. The genome coverage was confirmed by RFLP analysis of single-copy RFLP clones. The CS BAC library was used to develop simple sequence repeat (SSR) markers for targeted genome regions using five sequence-tagged-site (STS) markers designed from the chromosome arm of 3BS. The SSR markers for the targeted genome region were successfully obtained. However, similar numbers of new SSR markers were also generated for the other two homologous group 3 chromosomes. This data suggests that BAC clones belonging to all three chromosomes of homologous group 3 were isolated using the five STS primers. The potential impacts of these results on marker isolation in wheat and on library screening in general are discussed.

Maintenance therapy with a probiotic in antibiotic-dependent pouchitis: experience in clinical practice

BACKGROUND

Management of antibiotic-dependent pouchitis is often challenging. Oral bacteriotherapy with probiotics (such as VSL #3) as maintenance treatment has been shown to be effective in relapsing pouchitis in European trials. However, this agent has not been studied in the US, and its applicability in routine clinical practice has not been evaluated.

AIM

To determine compliance and efficacy of probiotic treatment in patients with antibiotic-dependent pouchitis.

METHODS

Thirty-one patients with antibiotic-dependent pouchitis were studied. VSL #3 is a patented probiotic preparation of live freeze-dried bacteria. All patients received 2 weeks of ciprofloxacin 500 mg b.d. followed by VSL #3 6 g/day for 8 months. Baseline Pouchitis Disease Activity Index scores were calculated. Patients' symptoms were reassessed at week 3 when VSL #3 therapy was initiated and at the end of the 8-month trial. Some patients underwent repeat pouch endoscopy at the end of the trial.

RESULTS

All 31 patients responded to the 2-week ciprofloxacin trial with resolution of symptoms and they were subsequently treated with VSL #3. The mean duration of follow-up was 14.5+/-5.3 months (range: 8-26 months). At the 8-month follow-up, six patients were still on VSL #3 therapy, and the remaining 25 patients had discontinued the therapy due to either recurrence of symptoms while on treatment or development of adverse effects. All six patients who completed the 8-month course with a mean treatment period of 14.3+/-7.2 months (range: 8-26 months) had repeat clinical and endoscopic evaluation as out-patients. At the end of 8 months, these six patients had a mean Pouchitis Disease Activity Index symptom score of 0.33+/-0.52 and a mean Pouchitis Disease Activity Index endoscopy score of 1.83+/-1.72, which was not statistically different from the baseline Pouchitis Disease Activity Index endoscopy score of 2.83+/-1.17 (P=0.27).

CONCLUSION

This study was conducted to evaluate bacteriotherapy in routine care. The use of probiotics has been adopted as part of our routine clinical practice with only anecdotal evidence of efficacy. Our review of patient outcome from the treatment placebo showed that only a minority of patients with antibiotic-dependent pouchitis remained on the probiotic therapy and in symptomatic remission after 8 months.

Human defensin 5 expression in intestinal metaplasia of the upper gastrointestinal tract

BACKGROUND

Upper gastrointestinal tract intestinal metaplasia (IM) is termed Barrett's oesophagus (BO) or gastric intestinal metaplasia (GIM), depending on its location. BO and GIM are associated with chemical exposure resulting from gastro-oesophageal reflux and chronic Helicobacter pylori infection, respectively. Paneth cells (PCs), characterised by cytoplasmic eosinophilic granules, are found in a subset of IM at these sites, but histology may not accurately detect them.

AIM

To determine human defensin 5 (HD5; an antimicrobial peptide produced by PCs) expression in BO and GIM, and to investigate its association with H pylori infection.

METHODS

Endoscopic biopsies from 33 patients with BO and 51 with GIM, and control tissues, were examined by routine histology and for H pylori infection and HD5 mRNA and protein expression.

RESULTS

In normal tissues, HD5 expression was specific for PCs in the small intestine. Five patients with BE and 42 with GIM expressed HD5, but few HD5 expressing cells in IM had the characteristic histological features of PCs. Most HD5 positive specimens were H pylori infected and most HD5 negative specimens were not infected.

CONCLUSIONS

HD5 immunohistochemistry was often positive in IM when PCs were absent by conventional histology. Thus, HD5 immunohistochemistry may be superior to histology for identifying metaplastic PCs and distinguishing GIM from BO. The higher frequency of HD5 expression in GIM than in BO is associated with a higher frequency of H pylori infection, suggesting that in IM PCs may form part of the mucosal antibacterial response.

Enhanced Maturation and Functional Capacity of Dendritic Cells Induced by Mannosylated L2 Domain of ErbB2 Receptor

The nature of antigens and functional state of dendritic cells (DC) are important in antigen presentation. The ability of DC for the induction of T-cell responses is promoted by maturation. It has been confirmed that mannose receptors mediate highly efficient endocytosis and presentation of mannosylated proteins. In the present study, L2 domain of ErbB2 ectodomain was expressed in Escherichia coli, purified and mannosylated. The maturation and functional capacity of DC induced by mannosylated L2 (mL2) protein were investigated. The results showed that L2 protein could induce DC maturation, which was accompanied by elevated expression of MHC and co-stimulatory molecules. The effect of mL2 protein on DC maturation was more remarkable than that of non-mL2 proteins. Uptake of mL2 antigens by DC was more efficient. Furthermore, the T cells can be stimulated to proliferate in vitro and secrete Th1 and Th2 cytokines. Higher levels of both IFN-gamma and IL-10 were detected from the T cells stimulated by mL2-pulsed DC, suggesting a concurrent activation of CD4+ and CD8+ T cells. The results demonstrated that L2 domain of ErbB2 receptor is an immunodominant molecule. The mL2 domain of ErbB2 can induce an enhanced maturation and functional capacity of DC. It may become an effective strategy to induce anti-ErbB2 response.