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Magnesium alloys are used as bone implants because of their good biocompatibility and degradability. However, due to the rapid and uneven degradation, its clinical application is limited. To improve the corrosion resistance of medical magnesium alloys, a novel technique of semisolid powder molding was used to prepare Mg-6Zn alloy, and then microarc oxidation (MAO) was firstly applied to modify the surface. In this study, the effects of different current densities (4, 6, 8 A/dm2) and microarc oxidation time (8, 14, 20 min) on the phase composition, thickness, density, microstructure, roughness, and corrosion resistance of MAO film were systematically studied, and then the optimized parameters were obtained. Finally, the optimized coating's biocompatibility (cytotoxicity, cell adhesion, hemolysis, osteogenic differentiation) was evaluated. The results show that the MAO film mainly comprises α-Mg, MgO, and Mg2SiO4. The film's roughness, microhardness, and thickness increase with the current density and oxidation time. The lowest electrochemical corrosion rate of the coating is (2.3 ± 0.5 × 10–4 mm/year under the parameter of 6 A/dm2-20 min, which decreases by about 3 orders of magnitude compared with naked Mg-6Zn (0.32 ± 0.06 mm/year). The optimized microarc oxidation parameter is 6 A/dm2-20 min, with a thickness of 18 ± 1.45 μm, and microhardness of 339.6 ± 9.09 HV (increases by 165.3%). Additionally, the cytotoxicity and hemolysis rate of naked and coated Mg-6Zn were reduced, but the cell viability and adhesion as well as the differentiation of osteoblast cells of coated Mg-6Zn were improved, exhibiting better biocompatibility. Therefore, semisolid powder molding can be used to prepare medical Mg alloys with high performance, and MAO improves corrosion resistance greatly. [ABSTRACT FROM AUTHOR]

Tumor growth is an angiogenesis-dependent process and accompanied by the formation of hypoxic areas. Tumstatin is a tumor-specific angiogenesis inhibitor that suppresses the proliferation and induces the apoptosis of tumorous vascular endothelial cells. VNP20009, an attenuated Salmonella typhimurium strain, preferentially accumulates in the hypoxic areas of solid tumors. In this study, a novel Salmonella-mediated targeted expression system of tumstatin (VNP-Tum5) was developed under the control of the hypoxia-induced J23100 promoter to obtain anti-tumor efficacy in mice. Treatment with VNP-Tum5 effectively suppressed tumor growth and prolonged survival in the mouse model of B16F10 melanoma. VNP-Tum5 exhibited a higher efficacy in inhibiting the proliferation and inducing the necrosis and apoptosis of B16F10 cells in vitro and in vivo compared with VNP (control). VNP-Tum5 significantly inhibited the proliferation and migration of mouse umbilical vascular endothelial cells to impede angiogenesis. VNP-Tum5 downregulated the expression of anti-vascular endothelial growth factor A, platelet endothelial cell adhesion molecule-1, phosphorylated phosphoinositide 3 kinase, and phosphorylated protein kinase B and upregulated the expression of cleaved-caspase 3 in tumor tissues. This study is the first to use tumstatin-transformed VNP20009 as a tumor-targeted system for treatment of melanoma by combining anti-tumor and anti-angiogenic effects. [ABSTRACT FROM AUTHOR]

The tumor suppressor protein p53 interacts with DNA in a sequence-dependent manner. Thousands of p53 binding sites have been mapped genome-wide in normal and cancer cells. However, the way p53 selectively binds its cognate sites in different types of cells is not fully understood. Here, we performed a comprehensive analysis of 25 published p53 cistromes and identified 3,551 and 6,039 ‘high-confidence’ binding sites in normal and cancer cells, respectively. Our analysis revealed 2 distinct epigenetic features underlying p53-DNA interactionsin vivo. First, p53 binding sites are associated with transcriptionally active histone marks (H3K4me3 and H3K36me3) in normal-cell chromatin, but with repressive histone marks (H3K27me3) in cancer-cell chromatin. Second, p53 binding sites in cancer cells are characterized by a lower level of DNA methylation than their counterparts in normal cells, probably related to global hypomethylation in cancers. Intriguingly, regardless of the cell type, p53 sites are highly enriched in the endogenous retroviral elements of the ERV1 family, highlighting the importance of this repeat family in shaping the transcriptional network of p53. Moreover, the p53 sites exhibit an unusual combination of chromatin patterns: high nucleosome occupancy and, at the same time, high sensitivity to DNase I. Our results suggest that p53 can access its target sites in a chromatin environment that is non-permissive to most DNA-binding transcription factors, which may allow p53 to act as a pioneer transcription factor in the context of chromatin. [ABSTRACT FROM PUBLISHER]

Introduction: Next-generation-sequencing (NGS) is increasingly used in clinical and research protocols for patients with cancer. NGS assays are routinely used in clinical laboratories to detect mutations bearing on cancer diagnosis, prognosis and personalized therapy. A typical assay may interrogate 50 or more gene targets that encompass many thousands of possible gene variants. Analysis of NGS data in cancer is a laborintensive process that can become overwhelming to the molecular pathologist or research scientist. Although commercial tools for NGS data analysis and interpretation are available, they are often costly, lack key functionality or cannot be customized by the end user. Methods: To facilitate NGS data analysis in our clinical molecular diagnostics laboratory, we created a custom bioinformatics tool termed Houston Methodist Variant Viewer (HMVV). HMVV is a Java-based solution that integrates sequencing instrument output, bioinformatics analysis, storage resources and end user interface. Results: Compared to the predicate method used in our clinical laboratory, HMVV markedly simplifies the bioinformatics workflow for the molecular technologist and facilitates the variant review by the molecular pathologist. Importantly, HMVV reduces time spent researching the biological significance of the variants detected, standardizes the online resources used to perform the variant investigation and assists generation of the annotated report for the electronic medical record. HMVV also maintains a searchable variant database, including the variant annotations generated by the pathologist, which is useful for downstream quality improvement and research projects. Conclusions: HMVV is a clinical grade, low-cost, feature-rich, highly customizable platform that we have made available for continued development by the pathology informatics community. [ABSTRACT FROM AUTHOR]

3′-Phosphoadenosine-5′-phosphosulfate (PAPS) is the obligate cosubstrate and source of the sulfonate group in the chemoenzymatic synthesis of heparin, a clinically used anticoagulant drug. Previously, we have developed a method to synthesize PAPS with Escherichia coli crude extracts, which include three overexpressed enzymes and a fourth unidentified protein. The unknown protein degrades adenosine diphosphate (ADP), the by-product of PAPS synthesis reaction. To further understand and control the process of in vitro enzymatic PAPS synthesis, we decide to identify the fourth protein and develop a defined method to synthesize PAPS using purified enzymes. Here, we show that the purified Nudix hydrolase NudJ degrades ADP at high efficiency and serves as the fourth enzyme in PAPS synthesis. Under the defined condition of PAPS synthesis, all of the 10-mM ADP is hydrolyzed to form adenosine monophosphate (AMP) in a 15-min reaction. ADP is a better substrate for NudJ than adenosine triphosphate (ATP). Most importantly, the purified NudJ does not cleave the product PAPS. The removal of ADP makes the PAPS peak more separable from other components in the chromatographic purification process. This developed enzymatic approach of PAPS production will contribute to the chemoenzymatic synthesis of heparin. [ABSTRACT FROM AUTHOR]

Background: Tongxinluo (TXL), consisting of 12 Chinese Materia Medica items catalogued in the Chinese Pharmacopoeia, is commercially available in China, South Korea, and Russia. Hundreds of randomized clinical trials (RCTs) on TXL in treating cardiovascular diseases were conducted and published in China. This study provides a comprehensive Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant systematic review with sensitivity and subgroup analyses to evaluate the evidence about whether TXL is more effective than isosorbide dinitrate (ISDN) in treating ischemic heart disease, particularly angina pectoris. Methods: RCTs published between 1996 and 2010 on TXL versus ISDN in treating angina pectoris for at least 4 weeks were retrieved from eight bibliographical databases (e.g., MEDLINE,® PubMed, Chinese National Knowledge Infrastructure, Cochrane Library, and WanFang Data). The quality of RCTs was assessed with the Jadad scale. Meta-analysis was performed to estimate the overall effects based on symptomatic and electrocardiographic (ECG) improvements. Subgroup analysis, sensitivity analysis, and meta-regression were conducted on the study characteristics of RCTs. Results: Twenty (20) RCTs with a total of 1936 participants were included after eligibility assessment. The Jadad score of all included studies was 2. The means of summary odds ratios (ORs) for comparing TXL and nitrates were 3.30 (95% confidence interval [CI] 2.37-4.58) by symptoms ( n=20) and 2.38 (95% CI 1.846-3.09) by ECG ( n=18). There was a significant correlation of ORs between symptoms and ECG (ρ=0.77 and p=0.00026). Subgroup analysis, sensitivity analysis, and meta-regression found no significant difference in overall effects among all study characteristics except the years of publication ( p=0.0409). Conclusions: The meta-analysis of 20 eligible RCTs demonstrates moderate evidence that TXL is more effective than ISDN for treating angina pectoris. This result warrants further RCTs of multicenters/countries, larger sample sizes, and higher quality. [ABSTRACT FROM AUTHOR]