Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs

The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.

Design methodology and performance analysis of application-oriented flexure hinges

Flexure hinges are widely employed in miniature and ultra-precision equipments with the development of precision engineering. In this paper, Castigliano's theorem and Labotto quadrature formula are utilized to derive the compliance matrix. An exclusive longitudinal section of corner-filleted flexure hinges is proposed and the curve of the cross-section is expressed by basic design parameters (r0, d, and l) and machining error parameter (η). The influences of parameters are analyzed by the defined evaluation indexes, i.e., rotation capacity, relative flexibility, and relative rotation error, which are used to assess the quality of flexure hinges. The analysis results indicate small d and optimized values of r0, l, and η will improve flexure hinges' performances. The proposed method is verified by finite element method and experiments within a 5% margin of error.

Obesity, diabetes, and survival outcomes in a large cohort of early-stage breast cancer patients

BACKGROUND

To determine the relationship between obesity, diabetes, and survival in a large cohort of breast cancer patients receiving modern chemotherapy and endocrine therapy.

PATIENTS AND METHODS

We identified 6342 patients with stage I-III breast cancer treated between 1996 and 2005. Patients were evaluated according to body mass index (BMI) category and diabetes status.

RESULTS

In a multivariate model adjusted for body mass index, diabetes, medical comorbidities, patient- and tumor-related variables, and adjuvant therapies, relative to the normal weight, hazard ratios (HRs) for recurrence-free survival (RFS), overall survival (OS), and breast cancer-specific survival (BCSS) for the overweight were 1.18 [95% confidence interval (CI) 1.02-1.36], 1.20 (95% CI 1.00-1.42), and 1.21 (95% CI 0.98-1.48), respectively. HRs for RFS, OS, and BCSS for the obese were 1.13 (95% CI 0.98-1.31), 1.24 (95% CI 1.04-1.48), and 1.23 (95% CI 1.00-1.52), respectively. Subset analyses showed these differences were significant for the ER-positive, but not ER-negative or HER2-positive, groups. Relative to nondiabetics, HRs for diabetics for RFS, OS, and BCSS were 1.21 (95% CI 0.98-1.49), 1.39 (95% CI 1.10-1.77), and 1.04 (95% CI 0.75-1.45), respectively.

CONCLUSIONS

In patients receiving modern adjuvant therapies, obesity has a negative impact on RFS, OS, and BCSS; and diabetes has a negative impact on RFS and OS. Control of both may be important to improving survival in obese and diabetic breast cancer patients.

[Gly14]-Humanin reduces histopathology and improves functional outcome after traumatic brain injury in mice

Humanin (HN) has been identified as an endogenous peptide that inhibited AD-relevant neuronal cell death. HNG, a variant of HN in which the 14th amino acid serine was replaced with glycine, can reduce infarct volume and improve neurological deficits after ischemia/reperfusion injury. In this study, we aimed to examine the neuroprotective effect of HNG on traumatic brain injury (TBI) in mice and explored whether the protective effect was associated with regulating apoptosis and autophagy. Compared to vehicle-treated groups, mice administered HNG intracerebroventricularly (i.c.v.) prior to TBI had decreased cells with plasmalemma permeability in the injured cortex and hippocampus (48 h, P<0.01), reduced brain lesion volume (days 14 and 28, P<0.05), improved motor performance (days 1-4, P<0.05) and ameliorated performance in the Morris water maze test (days 11-13, P<0.05) post TBI. Reduced lesion volume (day 14, P<0.05) was also observed even when HNG was administered intraperitoneally (i.p.) at 1h and 2h post TBI, and minor amelioration in motor and Morris water maze test deficits was also observed. Immunoblotting results showed that HNG pretreatment (i.c.v.) reversed TBI-induced cleavage of cysteinyl aspartate-specific protease-3 and poly ADPribose-polymerase and decline of Bcl-2, suppressed LC3II, Beclin-1 and vacuolar sorting protein 34 activation and maintained p62 levels in the injured cortex and hippocampus post TBI (compared with vehicle). In conclusion, HNG treatment improved morphological and functional outcomes after TBI in mice and the protective effect of HNG against TBI may be associated with down-regulating apoptosis and autophagy.

Novel surface display system for heterogonous proteins on Lactobacillus plantarum

AIMS

To establish a novel cell surface display system that would enable the display of target proteins on Lactobacillus plantarum.

METHODS AND RESULTS

BlastP analysis of the amino acids sequence data revealed that the N-terminus of the putative muropeptidase MurO from L. plantarum contained two putative lysin motif (LysM) repeat regions, implying that the MurO was involved in bacterial cell wall binding. To investigate the potential of MurO for surface display, green fluorescent protein (GFP) was fused to MurO at its C-terminus and the resulting fusion protein was expressed in Escherichia coli. After being mixed with L. plantarum cells in vitro, GFP was successfully displayed on the surfaces of L. plantarum cells. Increases in the fluorescence intensities of chemically pretreated L. plantarum cells compared to those of nonpretreated cells suggested that the peptidoglycan was the binding ligand for MurO. SDS sensitivity assay showed that the GFP fluorescence intensity was reduced after being treated with SDS. To demonstrate the applicability of the MurO-mediated surface display system, β-galactosidase from Bifidobacterium bifidium, in place of GFP, was functionally displayed on the surface of L. plantarum cells via MurO.

CONCLUSIONS

The MurO was a novel anchor protein for constructing a surface display system for L. plantarum.

SIGNIFICANCE AND IMPACT OF STUDY

The success in surface display of GFP and β-galactosidase opened up the feasibility of employing the cell wall anchor of MurO for surface display in L. plantarum.

PLTP regulates STAT3 and NFκB in differentiated THP1 cells and human monocyte-derived macrophages

Phospholipid transfer protein (PLTP) plays an important role in regulation of inflammation. Previously published studies have shown that PLTP binds, transfers and neutralizes bacterial lipopolysaccharides. In the current study we tested the hypothesis that PLTP can also regulate anti-inflammatory pathways in macrophages. Incubation of macrophage-like differentiated THP1 cells and human monocyte-derived macrophages with wild-type PLTP in the presence or absence of tumor necrosis factor alpha (TNFα) or interferon gamma (IFNγ) significantly increased nuclear levels of active signal transducer and activator of transcription 3, pSTAT3(Tyr705) (p<0.01). Similar results were obtained in the presence of a PLTP mutant without lipid transfer activity (PLTP(M159E)), suggesting that PLTP-mediated lipid transfer is not required for activation of the STAT3 pathway. Inhibition of ABCA1 by chemical inhibitor, glyburide, as well as ABCA1 RNA inhibition, reversed the observed PLTP-mediated activation of STAT3. In addition, PLTP reduced nuclear levels of active nuclear factor kappa-B (NFκB) p65 and secretion of pro-inflammatory cytokines in conditioned media of differentiated THP1 cells and human monocyte-derived macrophages. Our data suggest that PLTP has anti-inflammatory capabilities in macrophages.