Hypertension and risk of depression in the elderly: a meta-analysis of prospective cohort studies

The objective of the study was to assess the relationship between hypertension and risk of depression. The relationship between hypertension and depression has been discussed for a long time, but the results are controversial. Studies were searched from PubMed and Cochrane up to 24 March 2014. Any prospective cohort study, which possibly reported the relationship between hypertension and depression, was included. The random effect model was used to calculate the pooled relative risk (RR). Finally, five prospective cohort studies were included for analysis, with a total of 9647 participants involved. Our meta-analysis does not support that hypertension is probably a risk factor of depression. The pooled RR was 1.16 (95% confidence interval: 0.91, 1.42) when those exposed to hypertension were compared with those who were not. Subgroup analysis, sensitivity analysis and publication bias test suggested that the overall result of this analysis was robust. Further studies are needed to exclude the effects of other confounding factors.

Electron transport enhanced by electrode surface reconstruction: a case study of C60-based molecular junctions

At the C₆₀–Cu(111) interface, electrode surface reconstruction (Rec) increases electrical current compared to that for the unreconstructed (Unrec) surface.

Tuning the electron transport properties of boron-nitride nanoribbons with electron and hole doping

C chain doped BN nanoribbons can be either metallic or semiconducting, depending on how the C chains are located.

The survival benefit of kidney transplantation in obese patients

Obese patients have a decreased risk of death on dialysis but an increased risk of death after transplantation, and may derive a lower survival benefit from transplantation. Using data from the United States between 1995 and 2007 and multivariate non-proportional hazards analyses we determined the relative risk of death in transplant recipients grouped by body mass index (BMI) compared to wait-listed candidates with the same BMI (n = 208 498). One year after transplantation the survival benefit of transplantation varied by BMI: Standard criteria donor transplantation was associated with a 48% reduction in the risk of death in patients with BMI ≥ 40 kg/m(2) but a ≥ 66% reduction in patients with BMI < 40 kg/m2. Living donor transplantation was associated with ≥ 66% reduction in the risk of death in all BMI groups. In sub-group analyses, transplantation from any donor source was associated with a survival benefit in obese patients ≥ 50 years, and diabetic patients, but a survival benefit was not demonstrated in Black patients with BMI ≥ 40 kg/m(2). Although most obese patients selected for transplantation derive a survival benefit, the benefit is lower when BMI is ≥ 40 kg/m(2), and uncertain in Black patients with BMI ≥ 40 kg/m(2).

Ipr1 gene mediates RAW 264.7 macrophage cell line resistance to Mycobacterium bovis

Tuberculosis caused by Mycobacterium bovis (M. bovis) seriously affects efficiency of animal production with impacts on public health as well. Effective programmes of prevention and eradication of M. bovis infection therefore are urgently needed. Intracellular pathogen resistance gene 1 (Ipr1) is well known to mediate innate immunity to Mycobacterium tuberculosis (MTB), but there are no reports as to whether Ipr1 can enhance the phagocytic ability of macrophage against M. bovis. In this investigation, RAW 264.7 macrophage was transduced with lentiviral vector carrying Ipr1 (named Lenti-Ipr1); transgenic cells were identified by RT-PCR and western blotting. Transgenic positive cells (R-Ipr1) were then infected with an M. bovis virulent strain, with non-transduced cells used as control. When cell proliferation, viability and apoptosis of the two groups were investigated, it was found that infected RAW 264.7 died by necrosis whereas R-Ipr1 underwent apoptosis. Furthermore, the numbers of intracellular bacteria in R-Ipr1 were lower than those in control cells (P < 0.05). To identify the role of Ipr1, we measured the genes of Casp3, Mcl-1 and NOS2A which associated with macrophage activation and apoptosis by real-time quantitative PCR. The results demonstrated that Ipr1 gene expression can enhance anti-M. bovis infection of macrophage. This establishes a basis for the future production of Ipr1-transgenic cattle to strengthen the tuberculosis resistance.

Efficacy and safety of enteric-coated mycophenolate sodium in combination with two glucocorticoid regimens for the treatment of active lupus nephritis

Mycophenolic acid, in combination with glucocorticoids, has been shown in a series of trials to be safe and effective for treatment of lupus nephritis. Regimens that permit glucocorticoid dose reduction without loss of efficacy would be advantageous. MyLupus was a 24-week, multicentre, open-label, study in patients with active proliferative lupus nephritis treated with enteric-coated mycophenolate sodium (EC-MPS), randomized to standard-dose ( n = 42) or reduced-dose ( n = 39) glucocorticoids. Complete response at week 24, the primary endpoint, was achieved in 19.8% (16/81) of patients (19.0% standard-dose, 20.5% reduced-dose; lower limit of 97.5% CI for the difference −15.9%, p = 0.098, i.e. non-inferiority was not shown). Partial response occurred in 42.0% of patients (34/81). From baseline to week 24, the mean global British Isles Lupus Assessment Group (BILAG) score decreased from 14.0 ± 5.4 to 5.0 ± 3.8 ( p < 0.001). The incidence of adverse events was 80.2% (65/81), most frequently gastrointestinal complications (31/81, 38.3%). Infections were reported in 57.1% and 35.9% of standard- and reduced-dose glucocorticoid patients, respectively ( p = 0.056), with herpes zoster in 16.7% and 0% ( p = 0.012). Three patients discontinued study medication due to adverse events. This exploratory study suggests that EC-MPS may facilitate glucocorticoid reduction without loss of efficacy in patients with active lupus nephritis, but results require confirmation in a controlled, longer-term study versus the current standard of care.

Rice dehydrin K-segments have in vitro antibacterial activity

Dehydrins are groups of plant proteins that have been shown to response to various environmental stimuli such as dehydration, elevated salinity, and low temperature. However, their roles in plant defense against microbes have not been demonstrated. In an attempt to discover plant antimicrobial proteins, we have screened a rice cDNA library and isolated several cDNAs coding for dehydrins. Protein extracts from Escherichia coli expressing these cDNAs were tested for their activity against Gram-positive bacteria (Bacillus pumilus, B. subtilis, Staphylococcus aureus, and Sarcina lutea) and Gram-negative bacteria (Escherichia coli and Xanthomonas oryzae pv. oryzae). The results indicate that the crude protein extracts exhibited antibacterial activities against the Gram-positive bacteria. However, dehydrins purified by immunoaffinity chromatography were not active against the bacteria. To pinpoint the dehydrin peptides that were responsible for the bactericidal activity, we expressed DNA sequences coding for truncated dehydrins containing either K- or S-segment and found that K-segment peptides, and not S-segment, were responsible for the antibacterial activities against Gram-positive bacteria. Antibacterial assay with synthetic K-segments indicated that the peptides inhibited growth of B. pumilus with minimum inhibition concentration and minimum bactericidal concentration of 130 and 400 μg/ml, respectively.

A clinical case-control study on the association between mannose-binding lectin and susceptibility to HIV-1 infection among northern Han Chinese population

Mannose-binding lectin (MBL) is a key molecule of the innate immune system and a competent to bind carbohydrates of a variety of microorganisms, resulting in complement activation and opsonophagocytosis against various pathogens. However, there is no systemic investigation on the MBL's role in innate immune responses against HIV-1 infection among northern Han Chinese. This study investigated the association between MBL and HIV-1 infection susceptibility among northern Han Chinese. A total of 91 HIV-1 infected patients and 91 HIV-1 seronegative healthy individuals were recruited. Six polymorphisms of MBL2 gene were genotyped by pyrosequencing. The quantitative measurement of serum MBL concentration and MBL complex activity were performed by ELISA. The CD4+ T-cell counts were determined by flow cytometry. The plasma viral loads of 91 HIV-1 infected patients were determined by bDNA method. The results show that there is an association between MBL and HIV-1 infection susceptibility among northern Han Chinese. The individuals with B variant, low serum MBL concentration and low MBL complex activity are more susceptible to HIV-1 infection.

Molecular characterization, expression pattern and association analysis of the porcine BTG2 gene

B-cell translocation gene 2 (BTG2), a member of the B-cell translocation gene family with anti-proliferative properties, have been characterized to be involved in cell growth, differentiation and survival. In this study, we cloned the full length sequences of cDNA and genomic DNA of BTG2 gene from the porcine skeletal muscle. Spatial expression analysis showed that the porcine BTG2 gene is expressed predominantly in muscle. Temporal expression analysis in longissimus dorsi muscle demonstrated that the expression of BTG2 gene has the highest expression at 60 days old in Large White while with a peak expression at 120 days old in Meishan. Temporal analysis also revealed that the expression of BTG2 gene is generally higher in Large White than in Meishan at all the developmental stages tested (65 days of conception and 3, 35, 60, 120, and 180 days of postnatal). A single nucleotide polymorphism (G417C) in the intron of BTG2 gene was then detected by PCR-RFLP in Large White × Meishan F2 resource population and association analysis suggested that this polymorphic site had significant association (P < 0.05) with the buttock fat thickness, fat percentage, lean muscle percentage, ratio of lean to fat and carcass length.

Isolation of an unusual strain of Edwardsiella tarda from turbot and establish a PCR detection technique with the gyrB gene

AIMS

The aim of this study was to report an unusual Edwardsiella tarda and develop an effective method to identify this bacterium.

METHODS AND RESULTS

During the spring and summer of 2006, an epizootic occurred among cultured turbot (Scophthalmus maximus) in Qingdao, China. A gram-negative, rod-shaped bacterium (designated as LTB-4) was isolated from the infected fish, and was proved to be virulent to turbot. Based on the 16S rDNA sequencing and phenotypic tests, the bacterial pathogen was identified as E. tarda. Unlike those commonly described E. tarda strains, no flagellate was observed. Partial gyrB genes were amplified from E. tarda using the universal primers of gyrB genes and sequenced. The polymerase chain reaction (PCR) primers for the gyrB gene were designed specific to E. tarda. It revealed positive amplification of the gyrB fragment in E. tarda, whereas other bacterial species were negative. In addition, the technique enabled the recognition of E. tarda from diseased fish.

CONCLUSIONS

The isolate was identified as E. tarda without flagellate and an effective method was developed to identify E. tarda based on using the gyrB gene as a taxonomic marker.

SIGNIFICANCE AND IMPACT OF THE STUDY

The unusual E. tarda was first reported in China and the PCR allowed the rapid and sensitive detection of E. tarda.

The influence of recombinant human BMP-2 on bone-implant osseointegration: biomechanical testing and histomorphometric analysis

The healing period for bone-implant osseointegration lasts 3-6 months or even longer. The aim of this study was to investigate whether osseointegration can be enhanced by the use of bone morphogenetic protein-2 (BMP-2). In the femurs of 8 Japanese white rabbits, 16 implants were applied with 1.0 mg recombinant human BMP-2 (rhBMP-2) as group A, and the other 16 implants without rhBMP-2 as group B. Calcein green 20 mg/kg and alizarin red 20 mg/kg were injected 4 and 8 weeks after implantation, respectively. At 12 weeks, the animals were killed. In 16 implant-bone blocks, binding strength was measured by pull-out test, and the extracted implants were observed under a scanning electronic microscope. The other blocks were analysed for percentage of marked bone adjacent to the implant surface by confocal laser scanning microscope. The pull-out strengths of group A were greater than that of group B (P<0.05). Scanning electronic microscopy (SEM) showed more calcified substances on the surface of the implants of group A than B. There was more marked bone around group A than B implants at 4 weeks (P<0.05) and 8 weeks (P<0.05). rhBMP-2 improves the quantity and quality of implant-bone osseointegration. Biomechanical testing and histomorphometric analysis are reliable methods to use in researching the implant-bone interface.

Identification of a differential gene HUMMLC2B between F1 hybrids Landrace x Yorkshire and their female parents Yorkshire

In order to investigate heterosis on a molecular basis, suppression subtractive hybridization was used to analyze the differences in gene expression between porcine F1 hybrids Landrace x Yorkshire and their female parents Yorkshire. From two specific subtractive cDNA libraries, the clones screened out by reverse Northern high-density blots screening were chosen to clone full-length cDNA by RACE. An expression-upregulated gene for Yorkshire skeletal muscle, designated as HUMMLC2B, was identified. Porcine HUMMLC2B contains an open reading frame (ORF) encoding 169 amino acids residues with 59 and 115 nucleotides in the 5' and 3' untranslated regions (UTRs), respectively. In the porcine genome, it contains seven exons separated by six introns. High allelic variations and four SINEs were detected in it. Comparison of derived amino acid sequence of HUMMLC2B with database sequences revealed highly conserved 12 amino acid residues in a putative calcium-binding region. RT-PCR analysis showed a tissue-specific pattern of expression in skeletal muscle and a similar level of expression during skeletal muscle development. The possible role of HUMMLC2B and its relation to porcine heterosis are discussed.

Engineering of the gut commensal bacterium Bacteroides ovatus to produce and secrete biologically active murine interleukin-2 in response to xylan

AIMS

The aim of this work was to engineer a gut commensal bacterium, Bacteroidesovatus, to produce and secrete a biologically active cytokine in a regulated manner as a basis for novel immunotherapies for chronic gut disorders.

METHODS AND RESULTS

Bacteroides ovatus was engineered to produce murine interleukin-2 (MuIL2) intracellularly in response to xylan in culture media by inserting the MuIL2 gene into the xylanase operon of the organism. A second strain was engineered to secrete MuIL2 by adding Bacteroides fragilis enterotoxin secretion signal sequence to the protein. The recombinant strains produced MuIL2 only in the presence of xylan as determined by ELISA of cell lysates and culture supernatants. The IL2-dependent cell line CTLL-2 was used to demonstrate that MuIL2 produced by both B. ovatus strains was biologically active. This activity could be blocked by an anti-IL2 neutralizing antibody. The xylan-inducible nature of this system was demonstrated by RT-PCR.

CONCLUSIONS

Bacteroides ovatus was successfully engineered to produce and secrete biologically active MuIL2 in a xylan-inducible manner.

SIGNIFICANCE AND IMPACT OF THE STUDY

The production and secretion of a biologically active mammalian protein by a member of the gut microflora could lead to the development of new long-term immunotherapies for inflammatory gut diseases.

Expression and distribution of matrix metalloproteinases and their inhibitors in the human iris and ciliary body

AIM

To determine the expression and distribution of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the normal human iris and ciliary body.

METHODS

Seven postmortem human eyes were fixed with formalin. The iris and ciliary body were dissected out and embedded in paraffin. The expression of MMPs -1, 2, 3, and 9, and TIMPs 1-4 in the iris and ciliary body was determined by a novel immunofluorescence technique and the results graded by masked observers.

RESULTS

Positive staining for MMPs and TIMPs was observed in all regions of the anterior uvea, and was more intense in the ciliary body than in the iris. Most MMPs and TIMPs showed similar patterns in their distribution. In the ciliary body, staining was strongest in the epithelium, and was localised to the epithelial cell cytoplasm, except for TIMP-3 which was strongly expressed in the basement membranes. In the iris, staining was most noticeable in the anterior border and anterior epithelial layer. Blood vessels in the stroma of the iris and ciliary body also stained moderately for MMPs and TIMPs.

CONCLUSION

Both MMPs and TIMPs are widely expressed in the anterior uvea, with a positive correlation between their expressions. Their differential localisation in the ciliary body suggests they may have a role in maintaining homeostasis in the uveal tract.