Differences in capabilities of different enzyme immunoassays to detect anti-hepatitis E virus immunoglobulin G in pigs infected experimentally with hepatitis E virus genotype 3 or 4 and in pigs with unknown exposure

Hepatitis E virus (HEV), a major cause of acute viral hepatitis in humans in many developing countries, is highly prevalent in the pig population worldwide. The objective of this study was to assess the capability of three porcine prototypes of a human enzyme-linked immunosorbent assay (ELISA), an in-house ELISA and a line-immunoassay (LIA) to detect anti-HEV antibodies in pigs infected experimentally with HEV (n = 57), known to be negative for HEV infection (n = 27), or with unknown exposure to HEV infection (field samples, n = 90). All 27 samples from non-infected pigs were negative with all five assays. The earliest detection of anti-HEV antibodies occurred at 14 days post-inoculation (dpi) with four of five assays. From 42 dpi, all samples from infected pigs were detected correctly as anti-HEV positive. Kappa analysis demonstrated substantial agreement among tests (0.62-1.00) at 14 dpi and complete agreement (1.00) at 56 dpi. The overall area under the curve for all quantitative tests as determined by receiver operator characteristic analysis ranged from 0.794 to 0.831 indicating moderate accuracy. The results showed that all five assays can detect anti-HEV IgG antibodies accurately in pigs infected experimentally with HEV. In field samples, a higher prevalence of anti-HEV IgG was found in breeding herds than in growing pigs (100% versus 66.7-93.9%). These serological assays should be very useful in veterinary diagnostic labs for HEV diagnosis in swine.

Lymphatic sparing versus lymphatic non-sparing laparoscopic varicocelectomy in children and adolescents: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to explore the true efficacy and potential advantages of lymphatic sparing laparoscopic varicocelectomy (LSV) over lymphatic non-sparing laparoscopic varicocelectomy (LNSV) in children and adolescents.

METHODS

A search was made for studies published up until 31 August 2010 using the terms "lymphatic sparing varicocelectomy", "laparoscopy", "adolescent" and "children" in the Medline, Embase, Ovid, Web of Science, and Cochrane databases. Randomized controlled trials (RCTs) and observational clinical studies (OCSs) comparing LSV and LNSV were included. A systematic review and meta-analysis was performed using odds ratios (ORs) for dichotomous variables.

RESULTS

Out of 127 studies, 2 RCTs and 4 OCSs were eligible for inclusion, comprising 489 cases of LSV and 307 cases of LNSV. The hydrocele rates after LSV were significantly lower than after LNSV (OR = 0.19; 95% confidence interval [CI] = 0.10 to 0.36; p < 0.00001). However, no significant difference was observed between LSV and LNSV with regard to recurrence (OR = 0.65; 95% CI = 0.32-1.33; p = 0.24) or catch-up growth (OR = 2.14; 95% CI =0.97-4.72; p = 0.06).

CONCLUSION

LSV is valuable in reducing the incidence of postoperative hydrocele, with similar recurrence and catch-up growth rates as LNSV. A series of RCTs are warranted to explore the efficacy of LSV in the management of varicocele in children and adolescents.

Methylprednisolone reduces the rates of postextubation stridor and reintubation associated with attenuated cytokine responses in critically ill patients

BACKGROUND

Treatment with corticosteroids can reduce the incidence of postextubation stridor (PES) and reintubation in critically ill adult patients, but the mechanisms remain unknown.

METHODS

A randomized, controlled clinical trial was conducted in an adult medical and surgical Intensive Care Unit (ICU) of a teaching hospital. Seventy-one patients who had a cuff leak percentage <24% of tidal volume received either a bolus injection of methylprednisolone at 40 mg (treated group, n=38) or normal saline (placebo group, n=33) 4 h prior to a planned extubation. The cuff leak percentage was re-assessed 1 h and 4 h post-injection. Eighty patients who had a cuff leak percentage ≥ 24% served as a control group. Plasma concentrations of multiple cytokines and C-reactive protein (CRP) were measured at baseline, 4 h and 24 h after the intervention.

RESULTS

The incidences of PES (15.8% vs. 39.4%, P<0.05) and reintubation rate (7.9% vs. 30.3%, P<0.05) were lower in the treated group compared to the placebo group. The plasma concentrations of IL-4 and IL-10 increased while the levels of IL-6 and IL-8 decreased at 24 h in the treated group compared to the placebo group. No difference in CRP levels was observed between the treated and placebo groups.

CONCLUSION

A single injection of methylprednisolone at the dose used 4 h prior to planned extubation effectively reduced the incidence of PES and the reintubation rate. These beneficial effects were associated with the up-regulation of IL-4 and IL-10 and the down-regulation of IL-6 and IL-8 in the critically ill adult patients.

Comparison of the diversity of the bacterial communities in the intestinal tract of adult Bactrocera dorsalis from three different populations

AIMS

To (i) identify the bacterial communities in the gut of oriental fruit fly (Bactrocera dorsalis) adult and (ii) determine whether the different surroundings and diets influence the bacteria composition.

METHODS AND RESULTS

Polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) fingerprinting was used to investigate bacterial diversity in the oriental fruit fly adult gut. The 16S rDNA cloned libraries from the intestinal tract of laboratory-reared (LR), laboratory sterile sugar-reared (LSSR) and field-collected (FC) populations of oriental fruit fly were compared. Phylogenetic analysis of 16S rDNA revealed that Gammaproteobacteria were dominant in the all samples (73·0-98·3%). Actinobacteria and Firmicutes were judged to be major components of a given library as they constituted 10% or more of the total clones of such library. The Flavobacteria, Deltaproteobacteria, Bacteroidetes and Alphaproteobacteria were observed in small proportions in various libraries. Further phylogenetic analyses indicated common bacterial phylotypes for all three libraries, e.g. those related to Klebsiella, Citrobacter, Enterobacter, Pectobacterium and Serratia. LIBSHUFF analysis showed that the bacterial communities of B. dorsalis from the three populations were significantly different from each other (P < 0·0085).

CONCLUSIONS

(i) The intestinal tract of B. dorsalis adult contains a diverse bacterial community, some of which are stable. (ii) Different environmental conditions and food supply could influence the diversity of the harboured bacterial communities and increase community variations.

SIGNIFICANCE AND IMPACT OF THE STUDY

Comparison of the microbial compositions and common bacterial species found in this paper may be very important for the biocontrol of B. dorsalis.

Enhancement of the hydrolysis activity of β-galactosidase from Geobacillus stearothermophilus by saturation mutagenesis

Thermostable β-galactosidase (BgaB) from Geobacillus stearothermophilus is characterized by its thermoactivity in the hydrolysis of lactose to produce lactose-free milk products. However, BgaB has limited activity toward lactose. We established a method for screening evolved mutants with high hydrolysis activity based on prediction of substrate binding sites. Seven amino acid residues were identified as candidates for substrate binding to galactose. To study the hydrolysis activity of these residues, we constructed mutants by site-saturation mutagenesis of these residue sites, and each variant was screened for its hydrolysis activity. The first round of mutagenesis showed that changes in amino acid residues of Arg109, Tyr272, and Glu351 resulted in altered hydrolysis activity, including greater activity toward ortho-nitrophenyl-β-d-galactopyranoside (oNPG). The mutants R109V and R109L displayed changes in the optimum pH from 7.0 to 6.5, and the mutant R109V/L displayed different substrate affinity and catalytic efficiency (k(cat)/K(m)). Mutant R109G showed complete loss of BgaB enzymatic activity, suggesting that Arg109 plays a significant role in maintaining hydrolysis activity. The optimum pH of mutant E351R increased from 7.0 to 7.5 and this mutant showed a prominent increase in catalytic efficiency with oNPG and lactose as substrates.

Optimal systolic and diastolic reconstruction windows for coronary CT angiography using 320-detector rows dynamic volume CT

AIM

To investigate the optimal pattern of systolic and diastolic reconstruction windows for coronary computed tomography (CT) angiography using 320-detector rows dynamic volume CT (DVCT).

MATERIAL AND METHODS

A prospective analysis was performed on the data from 77 patients who were admitted between December 2008 and July 2009 for DVCT. The images were reconstructed in 10% steps throughout the 10-100% of R-R interval. Data sets for the three major coronary arteries [right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX)] were evaluated by two independent readers. The quality of the images from each examined artery was graded from 1 (no motion artefacts) to 4 (severe motion artefacts over the entire vessel). The optimal systolic and diastolic reconstruction windows and the relationship between image quality and heart rate (HR) were analysed. The HR at which the optimal reconstruction window shifted from diastole to systole was predicted.

RESULTS

The average HR during imaging was 69.5±12.8 beats/min (range 46-102beats/min). HR was positively correlated with the proportion of systole (r=0.78, p<0.001). As HR increased, the optimal reconstruction windows shifted to later phases in both systole and diastole. Image quality for optimal systolic and diastolic reconstructions both deteriorated significantly with higher HRs (r=0.38, p<0.001; r=0.82, p<0.001). However, image quality in systolic reconstructions did not deteriorate as much as in diastolic reconstructions. The cut-off HRs at which optimal reconstruction intervals turned from diastole to systole was 90.8beats/min.

CONCLUSIONS

In patients with a low HR, the optimal coronary reconstruction window is in mid-late diastole. As the HR increases, systolic reconstruction often yields superior image quality compared with diastolic reconstruction.

Fine-mapping of quantitative trait loci for body weight and bone traits and positional cloning of the RB1 gene in chicken

Previously, a quantitative trait locus (QTL) that affects body weight (BW) at 4-12 weeks of age and carcass weight at 12 weeks of age had been mapped on chicken chromosome 1. After including more markers and individuals, the confidence interval was narrowed down to approximately 5.5 Mbps and located this QTL near a microsatellite marker (ADL328). This QTL is the same as the QTL for 12 bone traits, including metatarsus length and metatarsus circumference at 4, 6, 8, 10 and 12 weeks of age and keel length and metatarsus claw weight at 12 weeks of age, that was identified using the same population. In the current study, 1010 individuals from the Northeast Agricultural University F(2) resource population were used and 14 single-nucleotide polymorphism (SNPs) around ADL328 were developed to construct haplotypes, and an association analysis was performed to fine-map the QTL. The haplotypes were constructed on the basis of a sliding 'window', with three SNP markers included in each 'window'. The association analysis results indicated that the haplotypes in 'windows' 6-12 were significantly associated with BW and bone traits and suggested that the QTL for BW and bone traits was located between SNP8 and SNP14 or was in linkage disequilibrium with this region. The interval from SNP8 to SNP14 was approximately 400 kbps. This region contained five RefSeq genes (RB1, P2RY5, FNDC3A, MLNR and CAB39L) on the University of California Santa Cruz website. The RB1 gene was selected as a candidate gene and five SNPs were identified in the gene. The association results indicated that the RB1 gene was a major gene for BW and bone traits. The SNPs g.39692 G>A and g.77260 A>G in RB1 gene might be two quantitative trait nucleotides for BW and bone traits.

MiR-148a promotes apoptosis by targeting Bcl-2 in colorectal cancer

Apoptosis has a vital role in maintaining tissue homeostasis, and dysregulation of the apoptotic pathway is now widely recognized as a key step in tumourigenesis. Increasingly, evidence has demonstrated that microRNA (miRNA) can exert various biological functions in tumours by targeting oncogenes or tumour suppressors. Nevertheless, the role of miRNA in apoptosis remains unclear. Here we show that ectopical expression of miR-148a can induce apoptosis in colorectal cancer cells. In addition, MYB can inhibit miR-148a by directly acting on the transcription factor binding site in miR-148a gene and miR-148a can posttranscriptionally silence Bcl-2. Subsequently, the intrinsic apoptosis pathway is activated by releasing cytochrome c, cleaving caspase 9, caspase 3 and PARP, which eventually induce cancer-cell apoptosis. These findings are part of a hitherto undocumented apoptotic regulatory pathway in which a pleiotropic transcription factor controls the expression of a miRNA and the miRNA inhibits the target, leading to activation of an intrinsic mitochondrial pathway and tumour apoptosis.

Regulation of Ca(2+)-entry in pancreatic α-cell line by transient receptor potential melastatin 4 plays a vital role in glucagon release

Elevation in the intracellular Ca(2+) concentration stimulates glucagon secretion from pancreatic α-cells. The Transient Receptor Potential Melastatin 4 channel (TRPM4) is critical for Ca(2+) signaling. However, its role in glucagon secreting α-cells has not been investigated. We identified TRPM4 gene expression and protein in the αTC1-6 cell line using RT-PCR and immunocytochemistry. Furthermore, we performed a detailed biophysical characterization of the channel using the patch-clamp technique to confirm that currents typical for TRPM4 were present in αTC1-6 cells. To investigate TRPM4 function, we generated a stable knockdown clone using shRNA and a lentiviral vector. Inhibition of TRPM4 significantly reduced the responses to different agonists during Ca(2+) imaging analysis with Fura-2AM. The reduction in the magnitude of Ca(2+) signals resulted in decreased glucagon secretion. These results suggested that depolarization by TRPM4 may play an important role in controlling glucagon secretion from α-cells and perhaps glucose homeostasis.

The 3Ns chromosome of Psathyrostachys huashanica carries the gene(s) underlying wheat stripe rust resistance

Stripe rust (Puccinia striiformis tritici (Pst)) is one of the most destructive diseases of wheat in the world. Exploiting and utilizing stripe rust resistance genes of wild species has become an essential strategy for resistance breeding. Psathyrostachyshuashanica Keng ex Kuo is a wild species in Triticeae that has been used for wheat improvement because of its high resistance or immunity to stripe rust. In this study, 9 wheat-P. huashanica addition lines were characterized by Giemsa C-banding, genomic in situ hybridization (GISH), and disease resistance evaluation. Giemsa C-banding and GISH demonstrated that lines 163-5, 165-1, 183-5, 240-3, and 240-4 are P. huashanica 3Ns chromosome monosomic addition lines; lines 183-1 and 183-20 are P. huashanica 3Ns chromosome disomic addition lines; line 165-20 is a P. huashanica 3Ns and 4Ns chromosomes double disomic addition line, and line 219-1 is a P. huashanica 1Ns and 3Ns/5A chromosomes double disomic addition-substitution line. All these addition lines with P. huashanica 3Ns chromosome(s) expressed high resistance or immunity to stripe rust. By comparing the series of wheat-P. huashanica chromosome addition lines, we concluded that the P. huashanica 3Ns chromosome carries the gene(s) for resistance or immunity to stripe rust. These addition lines can be used as a donor source of novel stripe rust resistance to wheat breeding programs.