The correlation of hepatocyte nuclear factor 4 alpha and 3 beta with hepatitis B virus replication in the liver of chronic hepatitis B patients

Hepatocyte nuclear factors 4 alpha (HNF4alpha) and 3 beta (HNF3beta) are members of a group of liver-enriched transcription factors (LETFs) that play important roles in regulating the replication of hepatitis B virus (HBV). Using cell culture and animal models, we showed that HNF4alpha supports HBV replication in nonhepatic cells and HNF3beta inhibits HBV replication. However, the expression of HNF4alpha and HNF3beta in the liver tissue of chronic HBV-infected patients and the relationship between the levels of HNF4alpha and HNF3beta and HBV replication are unclear. In this study, liver biopsy specimens from 86 chronic HBV-infected patients were collected. The expression levels of HNF4alpha, HNF3beta, hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) were detected by an immunohistochemical technique and the level of HBV DNA was checked by in situ hybridization with serial sections from liver biopsy tissue samples. We show here that samples with higher levels of HNF4alpha expression also have higher levels of HBsAg, HBcAg and HBV DNA. In contrast, in samples with higher levels of HNF3beta expression, levels of HBsAg, HBcAg and HBV DNA were lower. There was a positive correlation between HNF4alpha expression and HBV replication, and a negative correlation between HNF3beta expression and HBV replication, in the liver of chronic HBV-infected patients. This suggests that HNF4alpha and HNF3beta likely participate in HBV replication in patients with HBV infection, or that HBV replication may somehow influence the expression of HNF4alpha and HNF3beta in the liver.

Mesangial medium with IgA1 from IgA nephropathy inhibits nephrin expression in mouse podocytes

BACKGROUND

IgA nephropathy (IgAN) is characterized by mesangial deposition of polymeric IgA1, and podocyte injury plays an important role in glomerulosclerosis of the disease. Our previous study indicated that medium of mesangial cells co-incubated with aggregated IgA1 (aIgA1), isolated from IgAN patients, down-regulated nephrin expression. Yet the mechanism remains unclear.

MATERIALS AND METHODS

Podocytes were incubated with a medium of mesangial cells co-incubated with aIgA1, which was isolated from IgAN patients, and enalaprilat (10(-5) M), valsartan (10(-5) M) and anti-mouse tumour necrosis factor-alpha antibody (50 ng mL(-1)) separately. Nephrin expression in podocytes was measured by real-time polymerase chain reaction and Western blot analysis.

RESULTS

The level of angiotensinogen and angiotensin-converting enzyme mRNAs in podocytes, as well as angiotensin, was also increased by a medium of mesangial cells co-incubated with aIgA1 from IgAN patients (P<0.05). Enalaprilat or valsartan partly improved nephrin expression when compared with that by podocytes exposed to the mesangial medium (P<0.05), while the nephrin expression of podocytes with enalaprilat or valsartan was lower than that of podocytes exposed to medium of mesangial cells stimulated by aIgA1 from healthy control (P<0.05). However, anti-mouse tumour necrosis factor-alpha antibody did not show any improvement in nephrin expression.

CONCLUSION

Our findings implicate that local renin angiotensin system activation in podocytes is partly involved in down-regulation of nephrin by mesangial medium in IgA nephropathy.

Excessive false-positive errors in single-arm phase II trials: A simulation-based analysis

6512

Background: The use of randomized phase II designs with an experimental arm and a standard-treatment control arm (R2PII) instead of a conventional single-arm design is clearly increasing in oncology. In practice, sample size, related cost issues, the belief that historical controls are adequate, and the use of a standard-treatment control arm in a phase II setting are frequently raised objections to R2PII trials. As the expense and complexity of definitive phase III trials increase, the ability of phase II trials to provide reliable and accurate results is critical. Methods: We investigated the ability of single arm vs R2PII trials to provide accurate conclusions by modeling variability in historical controls, patient outcome drifts independent of the tested therapy, and patient selection effects. Simulations compared R2PII and single-arm designs with binary endpoints under realistic parameters (e.g. alpha = beta = 0.10, historical control success rate = 20%, target success rate = 40%). Results: In the absence of variability in historical controls, estimated false positive and negative rates in both designs mirror the designated specifications. However, even in the presence of a modest drift effect in the population (mean 5% absolute shift in true control success rate), the false positive rate in single-arm designs is inflated two to three fold (to 20%-30%), while the R2PII retains the desired error rates. Greater confidence in historical controls in the single-arm design corrects only a small portion of the deviations. Increasing the sample size in each trial inflates the false positive error rate further to as much as 50%. Varying several sets of parameters gave similar results. Conclusions: In the presence of variability in historical controls, patient drift and/or selection effects, the false positive error rate of a single arm design is unacceptably high. In contrast, the R2PII design is reliable and robust despite the complexities in patient outcome drift and selection effects, and variability in historical control success rates. Given the rapid improvements in outcomes of many tumor types, the R2PII design should be the preferred method to evaluate novel agents in oncology in spite of the associated costs and the use of a reference control arm.

No significant financial relationships to disclose.

A pig-human comparative RH map comprising 20 genes on pig chromosome 13q41 that harbours the ETEC F4ac receptor locus

The enterotoxigenic Escherichia coli (ETEC) F4ac is a major cause of diarrhoea in newborn and young pigs. The locus for the intestinal ETEC F4ac receptor (F4acR) has been mapped to pig chromosome (SSC) 13q41 with known homology to human chromosome (HSA) 3q21 and q29. However, the causative gene and mutation(s) remain unknown. The aim of this study was to characterize gene-derived markers on SSC13q41 for fine mapping of the F4acR locus, and construct a high-resolution pig-human comparative map to select positional candidate genes for F4acR. Pig-specific sequence-tagged site markers were developed for 20 genes that are located in a 6.8-Mb region on HSA3q21 and q29, and a total of 34 single-nucleotide polymorphisms (SNPs) were identified in 14 of 20 markers developed. Eighteen markers were mapped to SSC13q41, while the other two markers (PLXNA1 and KLF15) were assigned to SSC13q32 and SSC7q13, respectively, by radiation hybrid mapping. This result showed that there was a small conserved segment on SSC7 corresponding to HSA3q21. A framework map comprising 18 markers on SSC13q41 was established, refining the synteny breakpoint on SSC13q41 to a region of 12.3 centiRay. The comparative radiation hybrid (RH) map revealed three interesting candidate genes for F4acR from the human genome, viz. MUC4, MUC13 and MUC20. Linkage analysis with six marker polymorphisms revealed that MUC4 had the most significant linkage with the F4acR locus.

Predictors of the scleroderma phenotype in fibroblasts from systemic sclerosis patients

BACKGROUND

Fibroblasts from skin lesions generally exhibit the scleroderma phenotype in the early stage of in vitro culture, and act as one of the most important samples to investigate systemic sclerosis. However, not all cell lines from patients show the scleroderma phenotype, and little prospective evidence can be relied on to predict the phenotype of fibroblasts from systemic sclerosis patients.

OBJECTIVE

This study aims to find the predictive factors related to fibroblast phenotypes.

METHODS

Fibroblast lines from 15 patients with systemic sclerosis were established through explant culture, with their scleroderma phenotypes being determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) of procollagen transcription. Logistic regression analysis was used to analyse the clinical data of these patients. Haematoxylin-eosin staining was performed to observe histopathological differences. Expression of methylation-related factors was detected by real-time reverse transcription-polymerase chain reaction.

RESULTS

Eight of the 15 fibroblast cell lines from patients with systemic sclerosis exhibited the scleroderma phenotype. Logistic regression analysis yielded an equation (Y = -9.718 + 2.525X1) in which X1 significantly represents the Valentini Disease Activity Index. Histopathology results demonstrated that the scleroderma phenotype was positively correlated with leucocyte infiltration. Further laboratory observations showed increased expression of Dnmt1 in the positive phenotype fibroblasts and a positive correlation between elevations of Dnmt1 and the maintenance period of the scleroderma phenotype.

CONCLUSIONS

The results of this study suggest that the Valentini Disease Activity Index and expression of Dnmt1 may act as indicators of the scleroderma phenotype in fibroblasts. Additionally, these data also imply that epigenetic factors, such as Dnmt1, may be involved in the maintenance of the scleroderma phenotype. Our analyses may be beneficial to the research in systemic sclerosis.

Evolutionary fate of rhizome-specific genes in a non-rhizomatous Sorghum genotype

What is the fate of organ-specific genes after the organ is lost? For Sorghum propinquum and Sorghum halepense genes that were previously shown to have rhizome-enriched expression, we have conducted comparative analysis of both coding regions and regulatory sequences in Sorghum bicolor (non-rhizomatousness) and S. propinquum (rhizomatousness). Most genes with rhizome-enriched expression appear to have similar numbers of paralogous copies in both genotypes, with only three of 24 genes studied showing significant differences in copy numbers. We detected no greater propensity for mutation in S. bicolor than in S. propinquum of genes with rhizome-enriched expression in the latter. Several cis-acting regulatory elements, particularly an Myb-binding core (AACGG) that is involved in the regulation of the mitotic cyclin, were more abundant in promoters of S. propinquum than in non-rhizomatous S. bicolor or Oryza sativa (rice). We suggest that many genes with rhizome-enriched expression in S. propinquum may serve multiple functions, with partial loss of some of these functions in S. bicolor but ongoing purifying selection acting to preserve the remaining functions. Expressed genes in polyploid S. halepense rhizomes appeared to be more frequently derived from the S. propinquum than the S. bicolor progenitor, but there was some evidence of formation of novel alleles and 'recruitment' of S. bicolor genes to rhizome-enriched expression in S. halepense, suggesting that polyploidy may have offered new evolutionary potential to S. halepense.

Brain magnetic resonance imaging abnormalities in neuromyelitis optica

OBJECTIVE

Brain abnormalities in neuromyelitis optica (NMO) attracted much attention. Our study was to identify the brain magnetic resonance imaging (MRI) abnormalities in Chinese NMO patients.

METHODS

Patients who fulfilled the latest diagnostic criteria of NMO proposed by Wingerchuk et al. [Neurology 66 (2006) 1485] and whose brain MRI did not meet the multiple sclerosis (MS) criteria of McDonald et al. [Ann Neurol 50 (2001) 121] were selected to perform MRI scanning of the brain, spinal cord and optic nerves.

RESULTS

Twenty-eight of 33 patients (84.8%) had abnormal MRI findings. Twenty-two patients (66.7%) presented with well-defined brain parenchymal lesions and the other six patients (18.2%) with macroscopic symmetrical diffuse hyperintensities in deep white matter. Fifteen of 22 patients had more than one lesion (> or =2 lesions) and the other seven patients had single lesion. In the supratentorium, most lesions were punctate or small round dot and non-specific in juxtacortical, subcortical and deep white matter regions, a few were patchy atypical confluent lesions. Brainstem was easily involved (14/33, 42.4%) especially in medulla (7/33, 21.2%).

CONCLUSIONS

This study demonstrates the characteristics of brain MRI abnormalities in Chinese NMO patients, which are helpful to the revision of diagnostic criteria for NMO.

Mode of action of abatacept in rheumatoid arthritis patients having failed tumour necrosis factor blockade: a histological, gene expression and dynamic magnetic resonance imaging pilot study

Objectives:

Abatacept is the only agent currently approved to treat rheumatoid arthritis (RA) that targets the co-stimulatory signal required for full T-cell activation. No studies have been conducted on its effect on the synovium, the primary site of pathology. The aim of this study was to determine the synovial effect of abatacept in patients with RA and an inadequate response to tumour necrosis factor alpha (TNFα) blocking therapy.

Methods:

This first mechanistic study incorporated both dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and arthroscopy-acquired synovial biopsies before and 16 weeks after therapy, providing tissue for immunohistochemistry and quantitative real-time PCR analyses.

Results:

Sixteen patients (13 women) were studied; all had previously failed TNFα-blocking therapy. Fifteen patients completed the study. Synovial biopsies showed a small reduction in cellular content, which was significant only for B cells. The quantitative PCR showed a reduction in expression for most inflammatory genes (Wald statistic of p<0.01 indicating a significant treatment effect), with particular reduction in IFNγ of −52% (95% CI −73 to −15, p<0.05); this correlated well with MRI improvements. In addition, favourable changes in the osteoprotegerin and receptor activator of nuclear factor kappa B levels were noted. DCE–MRI showed a reduction of 15–40% in MRI parameters.

Conclusion:

These results indicate that abatacept reduces the inflammatory status of the synovium without disrupting cellular homeostasis. The reductions in gene expression influence bone positively and suggest a basis for the recently demonstrated radiological improvements that have been seen with abatacept treatment in patients with RA.

Immune responses and enhanced disease resistance in Chinese drum, Miichthys miiuy (Basilewsky), after oral administration of live or dead cells of Clostridium butyrium CB2

Clostridium butyrium CB2 isolated from chickens was tested as a potential fish probiotic in the Chinese drum, Miichthys miiuy. Fish were fed live (CB), dead CB2 (D-CB) cells (10(8) cells g(-1)) or spent culture supernatant (SCS), for 30 days and challenged with Vibrio anguillarum or Aeromonas hydrophila. Survival was higher in both the CB and the CB-D fed groups, but the SCS group was not significantly different from the control. After feeding live or dead CB2 cells, there was increase in phagocytic activity of the head kidney macrophages, the lysozyme activity of serum and gut mucosa and immunoglobulin (Ig) level. The SCS group showed no obvious change in immune parameters. The results suggest that live or dead Clostridium butyrium CB2 has an immunomodulatory effect on fish.

Combination pharmacological cardioversion of permanent atrial fibrillation in post-prosthetic mitral valve replacement outpatients: a novel approach for the treatment of atrial fibrillation

This study explored the efficacy and safety of combination pharmacological cardioversion of permanent atrial fibrillation in outpatients following prosthetic mitral valve replacement. The study group comprised 99 outpatients who were randomly divided into two groups. In group 1 (n = 50), only ventricular heart rate was controlled. In group 2 (n = 49), combination pharmacological cardioversion therapy with low-dose oral amiodarone (2 mg/kg), captopril (0.25 mg/kg) and simvastatin (0.3 mg/kg) was administered daily. During 12 months of serial pharmacological treatment, the cardioversion rate was 6% for group 1 and 39% for group 2; the likelihood of cardioversion differed significantly between the two groups. In group 2, one patient developed severe pruritus that necessitated withdrawal from the study and six patients ceased captopril treatment after contracting a persistent cough. In summary, combination pharmacological cardioversion was found to be effective and safe in outpatients who had undergone prosthetic mitral valve replacement.

Dislocation-source shutdown and the plastic behavior of single-crystal micropillars

Dislocation dynamics simulations have been used to study the stress-strain response of single-crystal micropillars containing initial dislocation networks generated via a relaxation procedure intended to approximate real thermal annealing processes. We find that, when such networks are loaded, they exhibit periods of plastic deformation, caused by the operation of single junction-stabilized spiral sources, followed by intervals of purely elastic straining when the sources shut down. The results provide insight into the mechanisms responsible for the experimentally observed staircase stress-strain behavior.

A Study of the Regulating Gene of femA from Methicillin-resistant Staphylococcus aureus Clinical Isolates

The regulating gene of femA was studied in methicillin-resistant Staphylococcus aureus (MRSA). High-level MRSA, low-level MRSA and methicillin-sensitive S. aureus (MSSA) were identified by agar diffusion. β-Lactamases were detected by nitrocephin and the presence of the mecA gene was determined by polymerase chain reaction (PCR). Only isolates that were both β-lactamase-negative and mecA-positive were used. The femA gene and its 250 base pair (bp) upstream sequence were amplified by PCR and expression was determined by real-time fluorescent quantitative PCR. The 250 bp upstream sequence was labelled by BrightStar€ Psoralen–Biotin and detected by electrophoretic mobility shift assay (EMSA). Expression levels of femA in MSSA, low-level MRSA and high-level MRSA were 3.53 × 10−3%–29.91%, 5.54 × 10−3%–3.1 × 102% and 13.88–5.50 × 104%, respectively. EMSA detected a signal shift in 57 high-level MRSA isolates but not in four low-level MRSA and four MSSA strains. Expression of femA in high-level MRSA (non-β-lactamase-producing) was higher than in low-level MRSA and MSSA. The femA regulating gene probably lies in the 250 bp upstream sequence in MRSA and high-level expression is essential for high-level methicillin resistance.

Internet use and risk behaviours: an online survey of visitors to three gay websites in China

OBJECTIVES

To describe the risk behaviours of visitors to gay websites and to explore the role of the internet in the HIV transmission among the Chinese men who have sex with men (MSM).

METHODS

Between May and August 2006, visitors of three Chinese gay websites were invited to complete an online questionnaire about the use of the internet and risk sexual behaviours.

RESULTS

The median age of the online sample was 25 years old (range 18 to 64). Over three-quarters (77.6%) had an education of college or higher. Less than 44% of the online sample reported little or no risk for HIV transmission. These men had either had no anal intercourse (28.0%) or had always used a condom for anal intercourse (15.8%). Although only about half of the participants reported that their main purpose of visiting the gay websites was to look for sexual partners, most participants (86.1%) had used the internet to seek partners. Compared with men seeking sexual partners only on the internet, men seeking partners both in traditional gay venues and on the internet were older, less likely to be students and more likely to have unprotected anal intercourse, more than six sexual partners in the past 6 months and commercial sex behaviours.

CONCLUSION

The users of the gay websites are relatively young and well educated, and highly vulnerable to HIV/AIDS, given their low prevalence of consistent condom use and multiple-risk sexual behaviours. Effective intervention programmes should be implemented and strengthened in China, especially for those who seek sexual partners both on the internet and in traditional gay venues.

Vena caval filters for the prevention of pulmonary embolism

BACKGROUND

Pulmonary emboli can have potentially fatal consequences. Inferior vena caval filters are metal alloy devices that mechanically trap fragmented thromboemboli from the deep leg veins en route to the pulmonary circulation. Filters in current clinical use are designed to be introduced (and in the case of retrievable filters, removed) percutaneously. Although their deployment seems of theoretical benefit, their clinical efficacy and adverse event profile is unclear.

OBJECTIVES

To examine evidence for the effectiveness of vena caval filters in preventing pulmonary embolism (PE). Secondary outcomes were mortality, distal (to filter) thrombosis, and filter-related complications.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (last searched August 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2007, Issue 3, MEDLINE (1966 to August 2007), and EMBASE (1966 to August 2007). Filter manufacturers and clinicians interested in filters were contacted for information.

SELECTION CRITERIA

Controlled clinical trials (CCTs) and randomised controlled trials (RCTs) that examined the efficacy of filters in preventing PE were selected.

DATA COLLECTION AND ANALYSIS

Three authors extracted information independently. Incidence figures were extracted from survival tables. Dichotomous outcomes were analysed as hazard ratio estimates.

MAIN RESULTS

One RCT was included. The PREPIC (Prévention du Risque d'Embolie Pulmonaire par Interruption Cave) trial was an open RCT of 400 participants with documented proximal deep vein thrombosis (DVT) or PE and who received concurrent anticoagulation. Permanent caval filters prevented PE at eight years (HR 0.37, 95% CI 0.17 to 0.79, in favour of the filter). No reduction in mortality was seen, but this reflected an older study population (mean age 73 years); the majority of deaths were due to cancer or cardiovascular causes. There was an increased incidence of DVT in the filter group (HR 1.52, 95% CI 1.02 to 2.27). No details were recorded of adverse events of filters.

AUTHORS' CONCLUSIONS

Limited generalisability prevents any conclusions to be drawn from the PREPIC trial in that permanent filters were used and the study lacked statistical power to detect a reduction in PE over shorter and more clinically significant time periods. However, the PREPIC trial demonstrated that permanent caval filters were associated with an increased risk of long term lower limb DVT. There is a marked paucity of caval filter outcomes evidence when used within their currently approved indications. There is also a lack of retrievable filter trials. Further trials are needed to assess vena caval filter safety and effectiveness.

Characterising alternate splicing and tissue specific expression in the chicken from ESTs

Alternate splicing is believed to produce the greatest diversity in transcriptional complexity and function in eukaryotic species. In this study, we present an analysis of alternative splicing events that occur in the chicken, using the recently sequenced genomic sequence and over 580,000 EST sequences mapped back to the genome. A carefully controlled EST-to-genome mapping pipeline is presented, based around the EXONERATE program using the est2genome model, which also considers several quality control steps to filter out erroneous matches. The data is then used to estimate the level of alternate splicing events with respect to Ensembl predicted transcripts. The EST-genome mappings are characterised at the exon level, in order to classify individual splicing events and provide estimates of novel transcripts not currently annotated by the Ensembl genome database. This is the first large scale analysis of this kind in an avian species, and suggests that chicken displays a similar level of alternate splicing as that found in other higher vertebrates such as human and mouse, both in terms of the number of genes that undergo alternate splicing events, and the average number of transcripts produced per gene. The EST data suggests alternate splicing may occur in some 50-60% of the chicken gene set and with an average of around 2.3 transcripts per gene which undergo this process. The EST data is also used to look at gene and transcript usage in the tissues sequenced in embryonic and adult libraries. Genes which display notable biases were analysed in more detail, including twinfilin-2 and embryonic heavy chain myosin. This also highlights several as yet functionally un-annotated genes which appear to be important in embryonic tissues and also undergo alternate splicing events. The analysis also demonstrates some of the difficulties involved in using EST-based data to annotate transcriptional activity in eukaryotic genes, where a broad spectrum of tissues and a large number of sequenced transcripts are required in order to fully characterise alternate splicing and differential expression.

The g.243A>G mutation in intron 17 of MUC4 is significantly associated with susceptibility/resistance to ETEC F4ab/ac infection in pigs

Using a porcine radiation hybrid panel, we assigned the mucin 4 (MUC4) gene to SSC13q41, which harbours the enterotoxigenic Escherichia coli (ETEC) F4ab/ac receptor locus. In addition, we identified two SNPs in intron 17 of MUC4 (DQ124298:g.243A>G and DQ124298:g.334A>G) in the parental population of a White Duroc x Erhualian cross. Association analysis showed that the MUC4 g.243A>G mutation was strongly associated with ETEC F4ab/ac, and especially with F4ac adhesion phenotypes in the White Duroc x Erhualian resource population, indicating that this polymorphism was in a significant linkage disequlibrium with the ETEC F4ab/ac receptor locus. Because of different linkage disequlibrium values between the ETEC F4ab and F4ac adhesion phenotypes and the MUC4 g.243A>G mutation, we argue that the inheritance of F4ab and F4ac receptors might be under the control of two closely linked loci.

Characterization of polymorphisms of transferrin receptor and their association with susceptibility to ETEC F4ab/ac in pigs

Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 (F4ab, F4ac and F4ad) fimbriae is a significant cause of mortality and morbidity in newborn and weaned pigs. The locus controlling susceptibility towards ETEC F4ab/ac has been mapped to SSC13q41, in which TFRC (transferrin receptor) was localized and considered as a positional candidate gene for ETEC F4ab/ac receptor. In this study, we determined susceptibility/resistance to ETEC F4ab/ac in a total of 755 F2 animals from a White Duroc x Erhualian intercross using a microscopic enterocyte adhesion assay. We identified two TFRC polymorphisms (SNPs 591 A>G and 632 A>G) in a single exon after comparative sequencing analysis of 2371-bp amplicons containing the complete coding region of TFRC using RNA of eight full-sib F2 animals with susceptible and resistant phenotypes. The intron sequences flanking the two exon polymorphisms were obtained, revealing an intron polymorphism (SNP 291 C>T). We genotyped the 19 founder animals of the White Duroc x Erhualian intercross for the identified polymorphisms, showing that only the 291 C>T polymorphism is a highly informative marker. We further genotyped all 59 F1 and 755 F2 animals for the 291 C>T polymorphism, and the association of this polymorphism with susceptibility/resistance to ETEC F4ab/ac in these F2 animals was evaluated by the transmission disequilibrium test. The result showed that the 291 C>T polymorphism is not a causal mutation, however, has a significant linkage disequilibrium with the ETEC F4ab/ac, especially F4ac receptor locus.