Aromatic residues in the oligonucleotide binding domain are essential to the function of the single-stranded DNA binding protein of Helicobacter pylori.

Single-stranded DNA-binding protein (SSB) is essential to DNA replication, DNA repair, and homologous genetic recombination. Our previous study on the crystal structure of a C-terminally truncated SSB from Helicobacter pylori, HpSSBc, in complex with single-stranded DNA (ssDNA) suggests that several aromatic residues, including Phe37, Phe50, Phe56, and Trp84, were involved in ssDNA binding. To investigate the importance of these aromatic residues, the binding activity of four site-directed HpSSB mutants, including F37A HpSSB, F50A HpSSB, F56A HpSSB, and W84A HpSSB, was compared to that of wild-type HpSSB and HpSSBc by means of electrophoresis mobility shift assay (EMSA), tryptophan quenching fluorescence titration, and surface plasmon resonance (SPR).

Species profile and reactivity of volatile organic compounds emission in solvent uses, industry activities and from vehicular tunnels.

A survey was conducted of the volatile organic compounds (VOCs) released from sources of solvent use, industry activities and vehicle emissions in Guiyang, a capital city of China. Samples were collected by canisters and analyzed by GC-MS-FID. The species profiles of VOCs emitted from sources were obtained.

Family outcome disparities between sexual minority and heterosexual families: a systematic review and meta-analysis.

Background: The number of children in sexual minority parent families has increased. This systematic review aims to synthesise the evidence of disparities in family outcomes between sexual minority and heterosexual families and to identify specific social risk factors of poor family outcomes.

Methods: We systematically searched PubMed, the Web of Science, Embase, the Cochrane Library and APA PsycNet for original studies that compared family outcomes between sexual minority and heterosexual families.

High baseline body mass index predicts recovery of CD4+ T lymphocytes for HIV/AIDS patients receiving long-term antiviral therapy.

The relationship between baseline BMI and CD4+ T cells during follow-up in HIV patients in China requires further evaluation. We conducted a retrospective cohort study based on adult AIDS patients who underwent or received antiretroviral therapy from 2003 to 2019 in Guangxi, China. BMI was divided into categories and compared, and after adjusting for BMI being related to the change in CD4 lymphocyte count, with normal weight as the reference group, the BMI before treatment was positively correlated with the changes in CD4+ T cells at different time periods.

Usability of dual HIV/syphilis self-testing among men who have sex with men in China: study protocol for a three-arm randomised controlled trial.

Introduction: HIV self-testing (HIVST) provides a key measure for the early detection of HIV infection in men who have sex with men (MSM). However, dual HIV/syphilis self-testing in the MSM population has not been studied. We describe a randomised controlled trial to evaluate the effect of dual HIV/syphilis self-testing on the testing frequency among MSM in China.

Volatile organic compounds emission in the rubber products manufacturing processes.

Volatile organic compounds (VOCs) emission from rubber products manufacture processes, mixing, shaping and vulcanization were investigated in four rubber products factories in China. The source emission air was passively sampled by pre-vacuumized stainless steel canister and analyzed by gas chromatography-mass spectrometry-flame ionization detection (GC/MS-FID). The species profile of 107 VOCs in the emission processes were obtained.

Individual and network factors associated with HIV self-testing among men who have sex with men in resource-limited settings in China.

Background: HIV self-testing (HIVST) is a potential strategy to overcome challenges of HIV testing among men who have sex with men (MSM). However, for resource-limited settings, technology and diagnostic devices are lagging. Hence, we estimated the status and correlates of HIVST among MSM in resource-limited settings in China to inform the development of HIVST to reach United Nations Programme on HIV and AIDS (UNAIDS) targets to end HIV by 2030.

Chained multimediator model of sexual orientation disclosure, sexual minority stigma, sexual minority identity, social support, and resilience among ymsms.

Introduction: This study aimed to investigate sexual orientation disclosure and mental health among young men who have sex with men (YMSMs). To this end, we constructed a chained multimediator model of sexual minority stigma, sexual minority identity, social support, and resilience, with the moderator of sexual orientation disclosure.

Methods: We conducted a cross-sectional survey of 345 YMSMs in Nanning, China.

Transformational Leadership and Employees' Thriving at Work: The Mediating Roles of Challenge-Hindrance Stressors.

Based on previous research, the conceptual model presenting the interaction between transformational leadership, challenge-hindrance stressors and thriving at work was constructed and used to generate the hypotheses for the study. Data were obtained from 542 questionnaires distributed across different organizations. The participants included ordinary employees, grassroots middle and senior managers from China.

Toll-like receptor 9 agonist enhances anti-tumor immunity and inhibits tumor-associated immunosuppressive cells numbers in a mouse cervical cancer model following recombinant lipoprotein therapy.

Background: Although cytotoxic T lymphocytes (CTLs) play a major role in eradicating cancer cells during immunotherapy, the cancer-associated immunosuppressive microenvironment often limits the success of such therapies. Therefore, the simultaneous induction of cancer-specific CTLs and reversal of the immunosuppressive tumor microenvironment may be more effectively achieved through a single therapeutic vaccine. A recombinant lipoprotein with intrinsic Toll-like receptor 2 (TLR2) agonist activity containing a mutant form of E7 (E7m) and a bacterial lipid moiety (rlipo-E7m) has been demonstrated to induce robust CTL responses against small tumors.

The effect of catalase on migration and invasion of lung cancer cells by regulating the activities of cathepsin S, L, and K.

Abundant clinical evidences indicate that up-regulation of several cathepsins in many human cancers is correlated with malignant progression and poor patient prognosis. In addition, a decrease in catalase activity or accumulation of hydrogen peroxide correlates with cancer metastasis. Recent studies indicate that cathepsin activation and expression can be modulated via H2O2 treatment.

Proteomic and redox-proteomic study on the role of glutathione reductase in human lung cancer cells.

Glutathione reductase (GR), a cytosolic protein, plays a vital role in maintaining a correct redox status in cells. However, comprehensive investigations of GR-modulated cellular responses, including protein level alteration and redox regulation, have yet to be performed. In this study, we cultured a human lung adenocarcinoma line transfected with empty pLKO.

Effects of novel human cathepsin S inhibitors on cell migration in human cancer cells.

Elevated cathepsin S (Cat S) level is correlated with higher migration ability in tumor cells. This study investigates the inhibitory effect of novel synthetic α-ketoamide compounds on cathepsin activity and cancer cell migration. The effect of several α-ketoamide compounds on the activity of recombinant cathepsins (Cat S, Cat L and Cat K) was examined.

Site-directed mutations of the gatekeeping loop region affect the activity of Escherichia coli spermidine synthase.

Spermidine synthase catalyzes the production of spermidine from putrescine and decarboxylated S-adenosylmethionine (dcSAM), and plays a crucial role in cell proliferation and differentiation. The gatekeeping loop identified in the structure of spermidine synthase was predicted to contain residues important for substrate binding, but its correlation with enzyme catalysis has not been fully understood. In this study, recombinant Escherichia coli spermidine synthase (EcSPDS) was produced and its enzyme kinetics was characterized.

Induction of oxidative DNA damage by flavonoids of propolis: its mechanism and implication about antioxidant capacity.

Propolis from beehives is commonly used as a home remedy for various purposes including as a topical antiseptic. Despite its antioxidant capacity, propolis induces oxidative DNA damage. In exploring the underlying mechanism, we found that the induction of oxidative DNA damage is attributed to the hydrogen peroxide (H(2)O(2)) produced by propolis.

Paclitaxel induces thrombomodulin downregulation in human aortic endothelial cells.

Patients with paclitaxel-eluting stents are at risk of developing stent thrombosis upon premature discontinuation of dual antiplatelet therapy. In this study, we set out to clarify whether paclitaxel can modulate thrombomodulin expression in human aortic endothelial cells. Human aortic endothelial cells were stimulated with paclitaxel.

Identification and biochemical characterization of a unique Mn2+-dependent UMP kinase from Helicobacter pylori.

Uridine monophosphate (UMP) kinase converts UMP to the corresponding UDP in the presence of metal ions and ATP and is allosterically regulated by nucleotides such as UTP and GTP. Although the UMP kinase reported to date is Mg(2+)-dependent, we found in this study that the UMP kinase of Helicobacter pylori had a preference for Mn(2+) over Mg(2+), which may be related to a conformational difference between the Mn(2+)-bound and Mg(2+)-bound UMP kinase. Similar to previous findings, the UMP kinase activity of H.

Modulation of tissue factor and thrombomodulin expression in human aortic endothelial cells incubated with high glucose.

Diabetes is often associated with atherothrombosis. It is unknown whether high glucose can modulate the expression of tissue factor (TF) and thrombomodulin (TM) in human aortic endothelial cells (HAECs). HAECs were treated with a lower-degree high glucose condition (LG, 11.

(-)-Epigallocatechin-3-gallate decreases thrombin/paclitaxel-induced endothelial tissue factor expression via the inhibition of c-Jun terminal NH2 kinase phosphorylation.

Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6h up to a concentration of 25 micromol/L.

Single-stranded DNA-binding protein complex from Helicobacter pylori suggests an ssDNA-binding surface.

Single-stranded DNA (ssDNA)-binding protein (SSB) plays an important role in DNA replication, recombination, and repair. SSB consists of an N-terminal ssDNA-binding domain with an oligonucleotide/oligosaccharide binding fold and a flexible C-terminal tail involved in protein-protein interactions. SSB from Helicobacter pylori (HpSSB) was isolated, and the ssDNA-binding characteristics of HpSSB were analyzed by fluorescence titration and electrophoretic mobility shift assay.

Paclitaxel induces up-regulation of tissue factor in human aortic endothelial cells.

Patients who underwent paclitaxel-eluting stent implantation are at a risk of developing late stent thrombosis. However, it is unclear whether paclitaxel alone can modulate tissue factor (TF) expression in human aortic endothelial cells (HAEC). HAEC were stimulated with paclitaxel.

Kinetic and structural properties of triosephosphate isomerase from Helicobacter pylori.

Triosephosphate isomerase (TIM) catalyzes the interconversion between dihydroxyacetone phosphate and D-glyceraldehyde-3-phosphate in the glycolysis-gluconeogenesis metabolism pathway. The Helicobacter pylori TIM gene (HpTIM) was cloned, and HpTIM was expressed and purified. The enzymatic activity of HpTIM for the substrate GAP was determined (K(m) = 3.

Activation of Helicobacter pylori inorganic pyrophosphatase and the importance of Cys16 in thermostability, enzyme activation and quaternary structure.

The inorganic pyrophosphatase from the human pathogen Helicobacter pylori (HpPPase) is a family I PPase. It is a homohexamer consisting of identical 20-kDa subunits. Hydrolysis of inorganic pyrophosphate (PP(i)) by HpPPase relied on the presence of magnesium and followed Michaelis-Menten kinetics, with k (cat) being 344 s(-1) and K (m) being 83 microM at pH 8.

Crystal structure of Helicobacter pylori spermidine synthase: a Rossmann-like fold with a distinct active site.

Spermidine synthase (putrescine aminopropyltransferase, PAPT) catalyzes the transfer of the aminopropyl group from decarboxylated S-adenosylmethionine to putrescine during spermidine biosynthesis. Helicobacter pylori PAPT (HpPAPT) has a low sequence identity with other PAPTs and lacks the signature sequence found in other PAPTs. The crystal structure of HpPAPT, determined by multiwavelength anomalous dispersion, revealed an N-terminal beta-stranded domain and a C-terminal Rossmann-like domain.

Kinetic and structural properties of inorganic pyrophosphatase from the pathogenic bacterium Helicobacter pylori.

Inorganic pyrophosphatase (PPase) catalyzes the hydrolysis of pyrophosphate (PPi) to orthophosphate (Pi) and controls the level of PPi in cells. PPase plays an essential role in energy conservation and provides the energy for many biosynthetic pathways. The Helicobacter pylori pyrophosphatase (HpPPase) gene was cloned, expressed, purified, and found to have a molecular weight of 20 kDa.