Molecular mechanism of hepatitis B virus X protein function in hepatocarcinogenesis

Many factors are considered to contribute to hepatitis B virus(HBV)-associated hepatocellular carcinoma(HCC),including products of HBV,HBV integration and mutation,and host susceptibility. HBV X protein(HBx) can interfere with several signaling pathways associated with cell proliferation and invasion,and HBx C-terminal truncation has been suggested to impact the development of HCC. This review focuses on the pathological functions of HBx in HBV-induced hepatocarcinogenesis. As a transactivator,HBx can affect regulatory non-coding RNAs(nc RNAs),including micro RNAs and long nc RNAs. HBx is also involved in epigenetic modification and DNA repair. HBx interacts with various signal-transduction pathways,such as the p53,Wnt,and nuclear factor-κB pathways. We conclude that HBx hastens the development of hepatoma.

Is frailty associated with short-term outcomes for elderly patients with acute coronary syndrome？

BackgroundFrailty 由于老化并且逐渐地是在心血管的药的一个新预示的因素老病人的复杂自然。有希望地分析在哪个脆弱与 .MethodsPatients 变老的急性冠的症候群(交流) 为老病人预言短期的结果的方式有用、有意义 &#x02265；65 年，与从心病学的交流的诊断，部门和医学部门被包括从单个中心。包括医学症候群的临床的数据用全面医学评价被收集。脆弱根据临床的脆弱规模被定义，风险上的合作病态的影响被冠的动脉疾病(CAD ) 确定 &#x02014；特定的索引。病人们被跟随在上面由临床的访问或电话，咨询和中部的后续时间是 120 天。后面起来项目包括了所有原因死亡， unscheduled 回来访问，在里面医院和周期性的主要不利心血管的事件。Multivariable 回归幸存分析用考克斯 regression.ResultsOf 被执行 352 个病人，(43.18%) 152 根据学习仪器被认为脆弱(5 &#x02212； 7 在规模上) ，并且(26.42%) 93 中等或严重地被考虑脆弱(6 &#x02212； 7 在规模上) 。包括不能自制，秋天历史，视觉缺陷，听觉缺陷，便秘，长期的疼痛，睡觉混乱，牙齿的问题，焦虑或消沉的医学症候群，和谵妄比在非脆弱的病人更经常在脆弱的病人( P = 0.000 ， 0.031 ， 0.009 ， 0.014 ， 0.000 ， 0.003 ， 0.022 ， 0.000 ， 0.074 ，和 0.432 ，分别地)。为性别调整了，年龄，冠的动脉疾病的严厉(离开了主要冠的动脉损害) 并且由考克斯幸存分析的合作病态(CAD 特定的索引) ，脆弱被发现到强烈并且独立地为主要合成结果与风险被联系：所有原因死亡[危险比率(HR )= 5.393；95% CI：1.477 &#x02212； 19.692， P = 0.011 ] 并且 unscheduled 回来访问(HR = 2.832；95% CI：1.140 &#x02212； 7.037， P = 0.025 ).ConclusionsComprehensive 医学评价和临床的脆弱的规模在有交流的老病人的评估是有用的。脆弱强烈并且独立地与交流为老病人与短期的结果被联系。

Loss of Wnt5a and Ror2 protein in hepatocellular carcinoma associated with poor prognosis

AIM:To investigate the expression and clinical significance of Wnt member 5a (Wnt5a) and receptor tyrosine kinase-like orphan receptor 2 (Ror2) in hepatocellular carcinoma (HCC).METHODS:In HCC tissues obtained from 85 patients,the protein expressions of Wnt5a,Ror2,β-catenin,and Ki-67 via immunohistochemical staining using the Envision Plus System.The antibody binding was visualized with 3,3'-diaminobenzidine tetrahydrochloride (DAB) before brief counterstaining with Mayer's hematoxylin.The degree of immunohistochemical staining was recorded using a semiquantitative and subjective grading system.The mRNA expression of Ror2 was examined by real-time reverse transcription polymerase chain reaction,including nineteen of the 85 HCC and three normal liver tissues.The ratios of Ror2 to the housekeeping gene GAPDH represented the normalized relative levels of Ror2 expression.To determine the prognostic factor,the outcome of the 82 patients was determined by reviewing their medical charts.The overall and disease-free survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test.The prognostic analysis was carried out with univariate and multivariate Cox regressions models.RESULTS:Compared to nontumorous (hepatitis or cirrhotic) tissues,Ror2 mRNA expression was clearly decreased in HCC.Ror2 and Wnt5a protein expressions in the majority of HCC patients (63% and 77%,respectively) was significantly less in tumor tissues,as compared to adjacent nontumorous tissues,and this reduction was correlated with increasing serum α-fetoprotein and tumor stage.In 68% (58/85) of the HCC cases,the expression of β-catenin in tumor tissues was either downregulated in the cellular membrane,upregulated in the cytoplasm,or both.Survival analysis indicated that Wnt5a and Ror2 protein expressions could be regarded as independent prognostic factors for HCC;HCC patients with decreased Wnt5a or Ror2 protein expression had a poorer prognosis than those with elevated Wnt5a and Ror2 expression (P=0.016,P=0.007,respectively).CONCLUSION:Wnt5a and Ror2 may serve as tumor suppressor genes in the development of HCC,and may serve as clinicopathologic biomarkers for prognosis in HCC patients.

COOH-terminal deletion of HBx gene is a frequent event in HBV-associated hepatocellular carcinoma

AIM:To investigate the hepatitis B virus (HBV) x gene (HBx) state in the tissues of HBV-related hepatocellular carcinoma (HCC) in Chinese patients and whether there were particular HBx mutations. METHODS: HBx gene was amplified and direct sequencing was used in genomic DNA samples from 20 HCC and corresponding non-cancerous liver tissues from HBsAg-positive patients. HBV DNA integration and HBx deleted mutation were validated in 45 HCC patients at different stages by Southern blot analysis and polymerase chain reaction methods. RESULTS: The frequencies of HBx point mutations were significantly lower in HCC than their corresponding non- cancerous liver tissues (11/19 vs 18/19, P = 0.019). In contrast, deletions in HBx gene were significantly higher in HCC than their non-cancerous liver tissues (16/19 vs 4/19, P < 0.001). The deletion of HBx COOH-terminal was detected in 14 HCC tissues. A specific integration of HBx at 17p13 locus was also found in 8 of 16 HCC, and all of them also exhibited full-length HBx deletions. Integrated or integrated coexistence with replicated pattern was obtained in 45.5% (20/45) - 56.8% (25/45) tumors and 40.9% (18/45) - 52.3% (23/45) non-tumor tissues. CONCLUSION: HBx deletion, especially the COOH- terminal deletion of HBx is a frequent event in HBV-associated HCC tissues in China. HBV integration had also taken place in partial HCC tissues. This supporting the hypothesis that deletion and probably integrated forms of the HBx gene may be implicated in liver carcinogenesis.

Prevalence and prognostic implications of sarcopenia in older patients with coronary heart disease

Background Sarcopenia is a progressive and generalized skeletal muscle disorder that is associated with an increased likelihood of adverse outcomes, including falls, fractures, physical disability, and mortality. However, there have been few systematic studies of the prevalence and prognostic values of sarcopenia in older patients with coronary heart disease(CHD). This study aimed to investigate the prevalence of sarcopenia in hospitalized older patients with CHD, and to prospectively evaluate the effect of sarcopenia on the short-term prognosis of these patients. Methods Patients aged ≥ 65 years, with the diagnosis of CHD from Peking Union Medical College Hospital between December 2017 and November 2018, were included. Sarcopenia was diagnosed according to consensus of the Asian Working Group for Sarcopenia in 2014. Follow-up items included unscheduled return visits, occurrence of major adverse cardiac and cerebral events (MACCE), and all-cause mortality. The MACCE-free survival curve of sarcopenic and non-sarcopenic older patients with CHD was estimated by the Kaplan-Meier method. Cox regression analysis was used to analyze the association between sarcopenia and an unscheduled return visits, MACCE, and all-cause mortality. Results A total of 345 older patients with CHD were enrolled in the study, with a median age of 74 years. Among the patients, 78 (22.6%) were diagnosed with sarcopenia. During the follow-up time, there were significantly more unscheduled return visits in sarcopenic patients than in non-sarcopenic patients (34.2% vs. 21.8%,χ^2 = 4.418, P = 0.036), while there was no significant difference in the occurrence of MACCE (χ^2 = 2.869, P = 0.09) or all-cause mortality (χ^2 = 1.673, P = 0.196) between these patient groups. The Kaplan-Meier curve showed that the MACCE-free survival time of sarcopenic patients was significantly shorter than that in non-sarcopenic patients (χ^2 = 4.102, P = 0.043). After adjusting for sex, age, and the Charlson comorbidity index, sarcopenia was not an independent risk factor of unscheduled return visits (HR = 1.002, 95% CI: 0.556–1.807). However, the complication of anxiety and depression was an independent risk factor (HR = 1.876, 95% CI: 1.012–3.477, P = 0.046) for unscheduled return visits in older patients with CHD. Conclusions There is a high prevalence of sarcopenia among hospitalized older adults with CHD. A shorter MACCE-free survival time and more unscheduled return visits are found in sarcopenic older patients with CHD. Clinicians should pay more attention to the functional status of older patients with CHD, as well as identification and management of geriatric syndromes.

Characterization of 12 polymorphic microsatellite markers in the Chinese tree shrew (Tupaia belangeri chinensis)

The Chinese tree shrew (Tupaia belangeri chinensis) is a small experimental animal with a close affinity to primates. This species has long been proposed to be an alternative experimental animal to primates in biomedical research. Despite decades of study, there is no pure breed for this animal, and the overall genetic diversity of wild tree shrews remains largely unknown. In order to obtain a set of genetic markers for evaluating the genetic diversity of tree shrew wild populations and tracing the lineages in inbreeding populations, we developed 12 polymorphic microsatellite markers from the genomic DNA of the tree shrew. An analysis of a wild population of 117 individuals collected from the suburb of Kunming, China, showed that these loci exhibited a highly expected heterozygosity (0.616). These 12 microsatellites were sufficient for individual identification and parentage analysis. The microsatellite markers developed in this study will be of use in evaluating genetic diversity and lineage tracing for the tree shrew.

Fluorescent co-localization of PTS1 and PTS2 and its application in analysis of the gene function and the peroxisomal dynamic in Magnaporthe oryzae

The peroxisomal matrix proteins involved in many important biological metabolism pathways in eukaryotic cells are encoded by nucleal genes, synthesized in the cytoplasm and then transported into the organelles. Targeting and import of these proteins depend on their two peroxisomal targeting signals (PTS1 and PTS2) in sequence as we have known so far. The vectors of the fluorescent fusions with PTS, i.e., green fluorescence protein (GFP)-PTS1, GFP-PTS2 and red fluorescence protein (RFP)-PTS1, were constructed and introduced into Magnaporthe oryzae Guy11 cells. Transformants containing these fusions emitted fluorescence in a punctate pattern, and the locations of the red and green fluorescence overlapped exactly in RFP-PTS1 and GFP-PTS2 co-transformed strains. These data indicated that both PTS1 and PTS2 fusions were imported into peroxisomes. A probable higher efficiency of PTS1 machinery was revealed by comparing the fluorescence backgrounds in GFP-PTS1 and GFP-PTS2 transformants. By introducing both RFP-PTS1 and GFP-PTS2 into Δmgpex6 mutants, the involvement of MGPEX6 gene in both PTS1 and PTS2 pathways was proved. In addition, using these transformants, the inducement of peroxisomes and the dynamic of peroxisomal number during the pre-penetration processes were investigated as well. In summary, by the localization and co-localization of PTS1 and PTS2, we provided a useful tool to evaluate the biological roles of the peroxisomes and the related genes.

A novel gain of function mutant in C-kit gene and its tumorigenesis in nude mice

AIM: To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor (GIST).METHODS: Eukaryotic expression vectors of pcDNA3-Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasmids were transfected into human embryonic kidney cell line by Lipofectamine. The resistant done was screened by G418filtration and identified by sequencing, Western blotting,and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared.RESULTS: The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3. pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line.Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-KitNW and pcDNA3-Kit-W (P＜0.05), respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW.CONCLUSION: Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.

Measurement of professional identity in Chinese nursing students

Objectives:Chinese nurses continue to display low professional identity.It is becoming an emergent issue in China how to help nurse students develop their positive professional identity.This paper is to develop the Professional Identity Scale for Nursing Students(PISNS).Methods:Literature review,and interviews with students and experts were adopted to develop initial item.Reliability and validity of the scale were respectively examined by computing internal consistency coefficient alpha and split-half Spearman Brown for equal length,and Exploratory Principle Component Factor Analysis.Results:Five factors with 17-item were obtained explaining 58.9%of the total variance.Cronbach’s alpha,and split-half reliability was 0.83 and 0.84 respectively.Conclusions:Given its high reliability and validity,PISNS could be used as a measurement tool for educators to evaluate the developing level of professional identity in nursing students and assess the effectiveness of corresponding interventions and strategies.

A simple and effective method for total RNA isolation of appressoria in Magnaporthe oryzae

Appressorium formation is an important event in establishing a successful interaction between the rice blast fungus, Magnaporthe oryzae, and its host plant, rice. An understanding of molecular events occurring in appressorium differentiation will give new strategies to control rice blast. A quick and reliable method to extract total RNA from appressorium is essential for studying gene expression during appressorium formation and its mechanism. We found that duplicate film is an efficient sub-stratum for appressorium formation, even when inoculated with high density conidia. When inoculated with conidia at 1×106 ml?1, the percentages of conidium germination and appressorium formation were (97.98±0.67)% and (97.88±0.45)%, respectively. We applied Trizol before appressorium collection for total RNA isolation, and as much as 113.6 μg total RNA was isolated from the mature appressoria at 24 h after inoculation. Functional analysis of two genes, MNH6 and MgATG1, isolated from the cDNA subtractive library, revealed that the quantity of RNA was good enough to construct a cDNA (complementary DNA) library or a cDNA subtractive library. This method may be also applicable for the appressorium RNA isolation of other pathogenic fungi in which conidia differentiate into appressoria in the early stages of host infection.

Ahmed valve implantation for neovascular glaucoma after 23-gauge vitrectomy in eyes with proliferative diabetic retinopathy

·AIM: To report on the outcome of Ahmed glaucoma valve (AGV) implantation for the management of neovascular glaucoma (NVG) after 23 -gauge vitrectomy for proliferative diabetic retinopathy (PDR). ·METHODS: Twelve medically uncontrolled NVG with earlier 23 -gauge vitrectomy for PDR underwent AGV implantation. The control of intraocular pressure (IOP), preoperative and postoperative best -corrected visual acuity, the development of intraoperative and postoperative complications were evaluated during the follow-up. ·RESULTS: The mean follow-up was 15.4±4.3 months (9-23 months). Mean preoperative IOP was 49.4±5.1mmHg and mean postoperative IOP at the last visit was 17.5 ± 1.6mmHg. The control of IOP was achieved at the final follow -up visits in all patients, however, 8 of 12 patients still needed anti-glaucoma medication (mean number of medications, 0.8±0.7). The visual acuity improved in nine eyes, and the visual acuity unchanged in three eyes at the final follow -up visits. The complications that occurred were minor hyphema in three eyes, choroid detachment in two eyes, and the minor hyphema and choroid detachments were reabsorbed without any surgical intervention. ·CONCLUSION: AGV implantation is a safe and effective procedure that enables successful IOP control and vision preservation in the NVG patients with the history of earlier 23-gauge vitrectomy for PDR.·

Angiopoietin-1 targeted RNA interference suppresses angiogenesis and tumor growth of esophageal cancer

AIM: To determine the inhibitory effect of the adenovirus- based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109. METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si (Eca109/Ang-1si), and Ad/si was used to infect Eca109 cells as control (Eca109/si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined. RESULTS: HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirus- transfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer.

Fruit and vegetable consumption and its relation to risk of asthenopia among Chinese college students

AIM： To investigate the associations between fruit and vegetable consumption and risk of asthenopia among Chinese college students. METHODS： A total of 1022 students were selected from five universities by a multi-stage stratified cluster sampling method. They were surveyed via a self-administered questionnaire including socio-demographic features, dietary and lifestyle habits, eye-related symptoms, eye care habits and history of diseases. Ascertainment of asthenopia was based on participants＇ subjectively reported symptoms. The associations between fruit and vegetable intake with asthenopia risk were assessed using multivariate logistic regression analysis. RESULTS： There were no significant associations between total fruit and vegetable, total vegetable, or fruit and the risk of asthenopia. Higher intake of dark-green leafy vegetable was likely to be inversely associated with asthenopia risk [odd ratio （OR）： 0.60; 95%CI： 0.37-0.97; Ptrend=0.21] after controlling for nondietary and dietary risk factors. Stratified analysis showed that the inverse association between dark-green leafy vegetable intake and asthenopia risk was limited to participants with suboptimal eyesight （OR： 0.45; 95%CI： 0.25-0.82; Ptrend=0.05）, wearing glasses （OR： 0.35; 95%CI： 0.17-0.72; Ptrend=0.03） or using computer ≥3h/d （OR： 0.48; 95%CI： 0.25-0.93; Ptrend=0.08）. CONCLUSION： A higher consumption of dark-green leafy vegetable is associated with a lower asthenopia risk among college students with suboptimal eyesight and poor eye care habits.

Characterization of 12 polymorphic microsatellite markers in the Chinese tree shrew(Tupaia belangeri chinensis)

The Chinese tree shrew(Tupaia belangeri chinensis)is a small experimental animal with a close affinity to primates.This species has long been proposed to be an alternative experimental animal to primates in biomedical research.Despite decades of study,there is no pure breed for this animal,and the overall genetic diversity of wild tree shrews remains largely unknown.In order to obtain a set of genetic markers for evaluating the genetic diversity of tree shrew wild populations and tracing the lineages in inbreeding populations,we developed 12 polymorphic microsatellite markers from the genomic DNA of the tree shrew.An analysis of a wild population of 117 individuals collected from the suburb of Kunming,China,showed that these loci exhibited a highly expected heterozygosity(0.616).These 12 microsatellites were sufficient for individual identification and parentage analysis.The microsatellite markers developed in this study will be of use in evaluating genetic diversity and lineage tracing for the tree shrew.

Magnaporthe oryzae MTP1 gene encodes a type Ⅲ transmembrane protein involved in conidiation and conidial germination

In this study the MTP1 gene, encoding a type Ⅲ integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily ex-pressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for patho-genicity. The Δmtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.

Controllable fabrication of self-organized nano-multilayers in copper–carbon films

In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.

Identification of tRNA-derived Fragments and Their Potential Roles in Atherosclerosis

Objective Atherosclerosis(AS),a chronic inflammatory disease,is the basis of cardiovascular disease(CVD).Although the treatment has been greatly improved,AS still imposes a large burden on human health and the medical system,and we still need to further study its pathogenesis.As a novel biomolecule,transfer RNA-derived fragments(tRFs)play a key role in the progression of various disease.However,whether tRFs contribute to atherosclerosis pathogenesis remains unexplored.Methods With deep sequencing technology,the change of tRFs expression profiles in patients with AS compared to healthy control group was identified.The accuracy of the sequencing data was validated using RT qPCR.Subsequently,we predicted the potential target genes of tRFs by online miRNA target prediction algorithms.The potential functions of tRFs were evaluated with Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses.Results There were 13 tRFs differentially expressed between patients with AS and healthy controls,of which 2 were up-regulated and 11 were down-regulated.Validation by RT-qPCR analysis confirmed the sequencing results,and tRF-Gly-GCC-009 was highly up-regulated in the AS group based on the results of sequencing which was confirmed by RT-qPCR analysis.Furthermore,GO enrichment and KEGG pathway analyses indicated that 10 signaling pathways were related to tRF-Gly-GCC-009.These pathways might be physiopathological fundamentals of AS,mainly involving in Apelin signaling,Notch signaling and calcium signaling.Conclusion The results of our study provide important novel insight into the underlying pathogenesis and demonstrate that tRFs might be potential biomarkers and therapeutic targets for AS in the future.

Impact of prosthesis-patient mismatch on early and late outcomes after mitral valve replacement:a meta-analysis

Background Prognostic significance of prosthesis-patient mismatch(PPM)after mitral valve replacement(MVR)remains uncertain because of the limited studies reporting inconsistent or even contrary results.This meta-analysis pooled results of all available studies comparing early and late prognoses between patients with significant mitral PPM and those without.Methods Studies were identified by searching Pubmed,Excerpta Medica Database,Cochrane Central Register of Controlled Trials,and Clinical Trials.gov.Impact of PPM on postoperative hemodynamic results,thirty-day mortality,overall mortality,mortality of thirty-day survivors,and primary morbidity after MVR was evaluated via meta-analysis.Robustness of pooled estimates,source of heterogeneity,and publication bias were assessed via sensitivity analyses,meta-regression as well as subgroup analysis stratified according to methodological or clinical heterogeneity,or sequential omission method,and funnel plot or Begg's and Egger's tests,respectively.Results Nineteen cohort studies involving 9302 individuals(PPM group:n=5109,Control group:n=4193)were included for meta-analysis.Total PPM and severe PPM prevalence were 3.8%–85.9%and 1%–27%,with a mean value of 54.9%and 14.1%,respectively.As compared with control group,mitral PPM group demonstrated a poorer postoperative hemodynamic status of higher mean and peak residual transprosthetic pressure gradients(TPG),higher postoperative systolic pulmonary artery pressure(SPAP)and less reduction,higher postoperative pulmonary hypertension(PH)prevalence and less PH regression,smaller net atrioventricular compliance,less NYHA class decrease,higher postoperative functional tricuspid regurgitation prevalence and less regression.The PPM group also revealed a higher thirty-day mortality,long-term overall mortality,mortality of thirty-day survivors,and postoperative congestive heart failure prevalence,which were positively correlated with the severity of PPM if it was classified into tri-level subgroups.Left ventricular end-diastolic diameter,postoperative atrial fibrillation(AF)prevalence,and the AF regression were analogous between groups.Most pooled estimates were robust according to sensitivity analyses.Male patients and bioprosthesis implantation proportion were prominent source of between-study heterogeneity on thirty-day mortality.Publication bias was not significant in tests for all the outcomes,except for SPAP and TPG.Conclusions Mitral PPM would result in poorer postoperative hemodynamics and worse early and late prognosis.Severe PPM must be avoided since deleterious impact of mitral PPM was severity dependent.

Vacuum current-carrying tribological behavior of MoS2-Ti films with different conductivities

Current-carrying sliding is widely applied in aerospace equipment,but it is limited by the poor lubricity of the present materials and the unclear tribological mechanism.This study demonstrated the potential of MoS_(2)-based materials with excellent lubricity as space sliding electrical contact materials by doping Ti to improve its conductivity.The tribological behavior of MoS_(2)-Ti films under current-carrying sliding in vacuum was studied by establishing a simulation evaluating device.Moreover,the noncurrent-carrying sliding and static current-carrying experiments in vacuum were carried out for comparison to understand the tribological mechanism.In addition to mechanical wear,the current-induced arc erosion and thermal effect take important roles in accelerating the wear.Arc erosion is caused by the accumulation of electric charge,which is related to the conductivity of the film.While the current-thermal effect softens the film,causing strong adhesive wear,and good conductivity and the large contact area are beneficial for minimizing the thermal effect.So the moderate hardness and good conductivity of MoS_(2)-Ti film contribute to its excellent current-carrying tribological behavior in vacuum,showing a significant advantage compared with the traditional ones.

Effect of Y-27632 on the cultured retinal neurocytes of rats

AIM:To investigate the effect of Y-27632 on the survival and neurite outgrowth of the cultured retinal neurocytes. METHODS:After the postnatal day 2-3, Sprague-Dawley retinal neurocytes were cultured for 48 hours, the culture media was replaced with serum-free media (control group) and serum-free media contained 30μmol/L Y-27632 (Y-27632 group), and the cells were continually cultured another 48 hours. The cultured retinal neurocytes were identified with anti-neuron specific enolase (NSE) immunocytochemistry. The survival state of those cells was estimated by MTT assay, and the neurite outgrowth of those cells was evaluated by the computerized image-analysis system. RESULTS:Compared with the control group, the absorbance values of cells survival in Y -27632 group increased 12.90% and 33.33% respectively after 72 and 96 hours culture. Y-27632 had no significant effect on the diameter of cultured retinal neurocytes. Compared with the control group, Y-27632 induced a stable improvement of neurite outgrowth of retinal neurocytes after 72 and 96 hours culture (P =0.001). CONCLUSION:Y-27632 could promote the survival and neurite outgrowth of the early postnatal cultured retinal neurocytes.