Meta-analysis of the effects of endoscopy with narrow band imaging in detecting dysplasia in Barrett's esophagus

Narrow band imaging (NBI) is a real-time imaging technique. The aim of this meta-analysis was to estimate the sensitivity, specificity, and diagnostic accuracy on the role of NBI in the detection and characterization of specialized intestinal metaplasia (SIM), high-grade dysplasia (HGD) in the Barrett's esophagus. We identified studies by performing a literature search of Medline, EMBASE, and the Cochrane Library databases up to May 2013. We performed data analysis using Meta-DiSc (version 1.4) software. To assess study quality and potential for bias, we used the Quality Assessment of Diagnostic Accuracy Studies-2 tool (QUADAS-2). Overall, seven eligible studies including over 3988 lesions of 502 patients were retrieved. The results showed that endoscopic diagnosis of dysplasia performed using NBI has a high diagnostic performance, with an area under the summary receiver operating characteristic (SROC) curve near 0.90 both in HGD lesions and SIM lesions. We also found that NBI has a sensitive and specificity of 0.91 (95% confidence interval [CI] = 0.86-0.94) and 0.85 (95% CI = 0.76-0.92) on a per-patient element, and 0.97 (95% CI = 0.95-0.98) and 0.64 (95% CI = 0.59-0.68) on a per-lesion element for SIM diagnosis, respectively. The pooled per-patient sensitivity and specificity for identifying HGD are 0.91 (95% CI = 0.75-0.98) and 0.95 (95% CI = 0.91-0.97). The pooled per-lesion sensitivity and specificity for identifying HGD are 0.69 (95% CI = 0.63-0.74) and 0.90 (95% CI = 0.88-0.91). In conclusion, we found that endoscopic diagnosis with NBI is an accurate test to diagnosis dysplasia of Barrett's esophagus.

The histone methyltransferase ESET is required for the survival of spermatogonial stem/progenitor cells in mice

Self-renewal and differentiation of spermatogonial stem cells (SSCs) are the foundation of spermatogenesis throughout a male's life. SSC transplantation will be a valuable solution for young male patients to preserve their fertility. As SSCs in the collected testis tissue from the patients are very limited, it is necessary to expansion the SSCs in vitro. Previous studies suggested that histone methyltransferase ERG-associated protein with SET domain (ESET) represses gene expression and is essential for the maintenance of the pool of embryonic stem cells and neurons. The objective of this study was to determine the role of ESET in SSCs using in vitrocell culture and germ cell transplantation. Cell transplantation assay showed that knockdown of ESET reduced the number of seminiferous tubules with spermatogenesis when compared with that of the control. Knockdown of ESET also upregulated the expression of apoptosis-associated genes (such as P53, Caspase9, Apaf1), whereas inhibited the expression of apoptosis-suppressing genes (such as Bcl2l1, X-linked inhibitor of apoptosis protein). In addition, suppression of ESET led to increase in expression of Caspase9 and activation of Caspase3 (P17) as well as cleavage of poly (ADP-ribose) polymerase. Among the five ESET-targeting genes (Cox4i2, spermatogenesis and oogenesis Specific Basic Helix-Loop-Helix 2, Nobox, Foxn1 and Dazl) examined by ChIP assay, Cox4i2 was found to regulate SSC apoptosis by the rescue experiment. BSP analyses further showed that DNA methylation in the promoter loci of Cox4i2was influenced by ESET, indicating that ESET also regulated gene expression through DNA methylation in addition to histone methylation. In conclusion, we found that ESET regulated SSC apoptosis by suppressing of Cox4i2 expression through histone H3 lysine 9 tri-methylation and DNA methylation. The results obtained will provide unique insights that would broaden the research on SSC biology and contribute to the treatment of male infertility.

Note: a Piezo Tip/Tilt Platform: structure, kinematics, and experiments

A Piezo Tip/Tilt Platform (PT(2)P) is presented with its structure, kinematics, and preliminary experiments. Two essential models of the presented PT(2)P, an equivalent hinge of the flexure hinge and a simplified model of the transmission mechanism, are discussed with the analysis on the structure of the PT(2)P. Based on these models, the inverse kinematics of the PT(2)P is derived. Two experiments are conducted on a prototype of the PT(2)P. The kinematic model is verified with experimental results, which also indicate that the resolution and the repeatability of the PT(2)P is, respectively, better than 0.50 μrad and 0.25 μrad.

Degradation of acetochlor by a bacterial consortium of Rhodococcus sp.T3-1, Delftia sp.T3-6 and Sphingobium sp.MEA3-1

Owing to acetochlor persistence in the environment and its perceptible threats to the ecosystem and human health, it is urgent to search for effective approaches to decontaminate acetochlor. In this study, an acetochlor-degrading enrichment culture was obtained by continuous enrichment from acetochlor-contaminated soil and named T3. T3 could completely degrade 100 mg l(-1) acetochlor and butachlor within 6 days. Two bacterial strains Rhodococcus sp.T3-1 and Delftia sp.T3-6 and one strain Sphingobium sp.MEA3-1 were isolated and identified from T3 by using acetochlor and MEA as sole carbon source, respectively. These three bacteria could completely mineralize acetochlor by the cooperative metabolism. The biochemical pathway of acetochlor degradation by these three bacteria in a consortium was proposed: acetochlor to 2'-methyl-6'-ethyl-2-chloroacetanilide (CMEPA) by Rhodococcus sp. T3-1, CMEPA to 2-methyl-6-ethyl aniline (MEA) by Delftia sp.T3-6 and MEA by Sphingobium sp.MEA3-1 based on the identified degradation intermediates. Under laboratory conditions, the consortium was effective in the acetochlor mineralization.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study presents a bacterial consortium consisting of Rhodococcus sp.T3-1, Delftia sp.T3-6 and Sphingobium sp.MEA3-1 could completely mineralize acetochlor by biochemical cooperation. The study reveals the metabolic mechanism of acetochlor biodegradation and highlights the potential of the bacterial consortium for cleaning up acetochlor and its metabolites subsisting in the environment.

Towards bond selective chemistry from first principles: methane on metal surfaces

Controlling bond-selective chemical reactivity is of great importance and has a broad range of applications. Here, we present a molecular dynamics study of bond selective reactivity of methane and its deuterated isotopologues (i.e., CH(4-x)D(x), x=0,1,2,3,4) on Ni(111) and Pt(111) from first principles calculations. Our simulations allow for reproducing the full C-H bond selectivity recently achieved experimentally via mode-specific vibrational excitation and explain its origin. Moreover, we also predict the hitherto unexplored influence of the molecular translational energy on such a selectivity as well as the conditions under which the full selectivity can be realized for the a priori less active C-D bond.

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.