Annexin-1 is an oncogene in glioblastoma and causes tumour immune escape through the indirect upregulation of interleukin-8.

Annexin-1 (ANXA1) is widely reported to be deregulated in various cancers and is involved in tumorigenesis. However, its effects on glioblastoma (GBM) remain unclear. Using immunohistochemistry with tissue microarrays, we showed that ANXA1 was overexpressed in GBM, positively correlated with higher World Health Organization (WHO) grades of glioma, and negatively associated with poor survival. To further explore its role and the underlying molecular mechanism in GBM, we constructed ANXA1shRNA U87 and U251 cell lines for further experiments. ANXA1 downregulation suppressed GBM cell proliferation, migration, and invasion and enhanced their radiosensitivity. Furthermore, we determined that ANXA1 was involved in dendritic cell (DC) maturation in patients with GBM and that DC infiltration was inversely proportional to GBM prognosis. Considering that previous reports have shown that Interleukin-8 (IL-8) is associated with DC migration and maturation and is correlated with NF-κB transcriptional regulation, we examined IL-8 and p65 subunit expressions and p65 phosphorylation levels in GBM cells under an ANXA1 knockdown. These results suggest that ANXA1 significantly promotes IL-8 production and p65 phosphorylation levels. We inferred that ANXA1 is a potential biomarker and a candidate therapeutic target for GBM treatment and may mediate tumour immune escape through NF-kB (p65) activation and IL-8 upregulation.

The efficacy and safety of immune checkpoint inhibitor in patients with relapsed small-cell lung cancer: A systematic review and meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: Immune checkpoint inhibitors (ICIs) have been approved for treating small-cell lung cancer (SCLC). However, the efficacy and safety profile of ICIs for relapsed SCLC remains under investigation. In this study, we assessed the efficacy and safety of ICIs in the treatment of relapsed SCLC patients. METHODS: The databases, including Pubmed, Embase, and the Cochrane library, were systematically searched to retrieve potential eligible studies from the establishment of the database to May 2021. The primary outcomes were survival, treatment responses, and safety. Randomized controlled trials and real-world studies that met the inclusion criteria were included. The RevMan 5.4 and R software were used for meta-analysis. RESULTS AND DISCUSSION: A total of eight articles involving 653 patients was included. Meta-analyses results showed that the overall response rate (objective response rate [ORR]) of the ICIs group was 0.12 (95% confidence interval [CI]: 0.07-0.18). The median overall survival was 7.97 (95% CI: 5.94-9.47) months, while the progression-free survival was 1.70 (95% CI: 1.40-2.28) months. Although chemotherapy showed a favourable ORR (odds ratio [OR] = 0.74; 95% CI: 0.39-1.41; p = 0.36) and a significantly better disease control rate (OR = 0.28; 95% CI: 0.11-0.70; p = 0.007), patients treated with ICIs had a reduced risk of mortality (hazard ratio = 0.87; 95% CI: 0.73-1.03; p = 0.10). With regards to adverse events (AEs), the rates of any AEs and ≥grade 3 AEs were 0.56 (95% CI: 0.52-0.60) and 0.13 (95%CI: 0.06-0.20), respectively. WHAT IS NEW AND CONCLUSION: For relapsed SCLC patients, the administration of ICIs resulted in a similar survival outcome and acceptable safety compared with chemotherapy. Further studies are needed to explore potential biomarkers for relapsed SCLC patients who may benefit from immunotherapy.

Overexpressed pseudogene MT1L associated with tumor immune infiltrates and indicates a worse prognosis in BLCA.

BACKGROUND: BLCA is a common cancer worldwide, and it is both aggressive and fatal. Immunotherapy (ICT) has achieved an excellent curative effect in BLCA; however, only some BLCA patients can benefit from ICT. MT1L is a pseudogene, and a previous study suggested that MT1L can be used as an indicator of prognosis in colorectal cancer. However, the role of MT1L in BLCA has not yet been determined. METHODS: Data were collected from TCGA, and logistic regression, Kaplan-Meier plotter, and multivariate Cox analysis were performed to demonstrate the correlation between the pseudogene MT1L and the prognosis of BLCA. To identify the association of MT1L with tumor-infiltrating immune cells, TIMER and TISIDB were utilized. Additionally, GSEA was performed to elucidate the potential biological function. RESULTS: The expression of MT1L was decreased in BLCA. Additionally, MT1L was positively correlated with immune cells, such as Tregs (ρ = 0.708) and MDSCs (ρ = 0.664). We also confirmed that MT1L is related to typical markers of immune cells, such as PD-1 and CTLA-4. In addition, a high MT1L expression level was associated with the advanced T and N and high grade in BLCA. Increased expression of MT1L was significantly associated with shorter OS times of BLCA patients (p < 0.05). Multivariate Cox analysis revealed that MT1L expression could be an independent prognostic factor in BLCA. CONCLUSION: Collectively, our findings demonstrated that the pseudogene MT1L regulates the immune microenvironment, correlates with poor survival, and is an independent prognostic biomarker in BLCA.

Ecological risks induced by consumption and emission of Pharmaceutical and personal care products in Qinghai-Tibet Plateau: Insights from the polar regions.

As the third pole of the world and Asia's water tower, the Tibetan Plateau experiences daily release of pharmaceutical and personal care products (PPCPs) due to increasing human activity. This study aimed to explore the potential relationship between the concentration and composition of PPCPs and human activity, by assessing the occurrence of PPCPs in areas of typical human activity on the Qinghai-Tibet Plateau and evaluating their ecological risk. The results indicate that 28 out of 30 substances were detected in concentrations ranging from less than 1 ng/L to hundreds of ng/L, with the average concentration of most PPCPs in the Tibet Autonomous Region being higher than that in Qinghai Province. Among the detected substances, CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounted for over 90% of the total concentration. The emission sources of PPCPs were identified by analyzing the correlation coefficients of soil and water samples, with excess PPCPs used by livestock breeding discharged directly into soil and then into surface water through leaching or runoff. By comparing the concentration and composition of PPCPs with those in other regions, this study found that CIP, ENR, LOM, NOR, CTC, DOX, OTC, and TCN were the most commonly used PPCPs in the Qinghai-Tibet Plateau. To assess the ecological risk of PPCPs, organisms at different trophic levels, including algae, crustaceans, fish, and insects, were selected. The prediction of the no effect concentration of each PPCP showed that NOR, CTC, TCN, CAF, and CBZ may have deleterious effects on water biota. This study can assist in identifying the emission characteristics of PPCPs from different types and intensities of human activities, as well as their occurrence and fate during the natural decay of aquatic systems.

TaACTIN7-D regulates plant height and grain shape in bread wheat.

Exploitation of new gene resources and genetic networks contributing to the control of crop yield-related traits, such as plant height, grain size, and shape, may enable us to breed modern high-yielding wheat varieties through molecular methods. In this study, via ethylmethanesulfonate mutagenesis, we identify a wheat mutant plant, mu-597, that shows semi-dwarf plant architecture and round grain shape. Through bulked segregant RNA-seq and map-based cloning, the causal gene for the semi-dwarf phenotype of mu-597 is located. We find that a single-base mutation in the coding region of TaACTIN7-D (TaACT7-D), leading to a Gly-to-Ser (G65S) amino acid mutation at the 65th residue of the deduced TaACT7-D protein, can explain the semi-dwarfism and round grain shape of mu-597. Further evidence shows that the G65S mutation in TaACT7-D hinders the polymerization of actin from monomeric (G-actin) to filamentous (F-actin) status while attenuates wheat responses to multiple phytohormones, including brassinosteroids, auxin, and gibberellin. Together, these findings not only define a new semi-dwarfing gene resource that can be potentially used to design plant height and grain shape of bread wheat but also establish a direct link between actin structure modulation and phytohormone signal transduction.

Staphylococcus aureus NorD, a putative efflux pump coregulated with the Opp1 oligopeptide permease, contributes selectively to fitness in vivo.

Staphylococcus aureus readily infects humans, causing infections from mild superficial skin infections to lethal bacteremia and endocarditis. Transporters produced by S. aureus allow the pathogen to adapt to a variety of settings, including survival at sites of infection and in the presence of antibiotics. The native functions of many transporters are unknown, but their potential dual contribution to fitness and antimicrobial resistance highlights their importance in staphylococcal infections. Here, we show that S. aureus NorD, a newly recognized efflux pump of the major facilitator superfamily, contributes to fitness in a murine subcutaneous abscess model. In community-associated methicillin-resistant S. aureus (CA-MRSA) strain MW2, norD was selectively upregulated 36-fold at the infection site relative to growth in vitro, and the norD mutant demonstrated significant fitness impairment in abscesses, with fitness 20- to 40-fold lower than that of the parent MW2 strain. Plasmid-encoded NorD could complement the fitness defect of the MW2 norD mutant. Chromosomal norD expression is polycistronic with the upstream oligopeptide permease genes (opp1ABCDF), which encode an ABC oligopeptide transporter. Both norD and opp1 were upregulated in abscesses and iron-restricted culture medium and negatively regulated by Fur, but only NorD contributed to fitness in the murine abscess model.

MT1X is an oncogene and indicates prognosis in ccRCC.

The metallothionein 1 (MT1) family was previously shown to be involved in metal ion homeostasis, DNA damage, oxidative stress, and carcinogenesis. Our team's previous study showed that MT1X is most closely associated with ccRCC. However, its role in clear cell RCC (ccRCC) remains unclear. The present study aimed to demonstrate MT1X's prognostic value, potential biologic function, impact on the immune system, and influence on cell growth, the cell cycle, apoptosis, and migration in the setting of ccRCC. The relationship between clinical pathologic features and MT1X was analyzed using bioinformatics. We knocked down MT1X in the ccRCC cell line 786O with si-MT1X to verify the results of the bioinformatic analysis at the cytological level. Apoptosis assay, cell cycle assay, wound-healing assay, colony formation assay, and RT-qPCR were performed. MT1X is correlated with the stage (T and M) and grade and is able to be an independent prognostic factor for ccRCC. The TISIDB database analysis showed a significant correlation between MT1X and tumor-infiltrating lymphocytes such as central memory CD8+ T cells and γΔT cells. MT1X was also positively related to immunomodulators such as TGFB1 and CXCR4. We also found that MT1X knockdown inhibits cell growth, induces apoptosis, arrests cells in the S cell cycle, and inhibits the wound healing proportion in ccRCC. Gene set enrichment analysis and quantitative PCR (q-PCR) analysis found that down-regulation of MT1X reduced the accumulation of hypoxia-associated factors. Bioinformatic analysis associated increased MT1X expression with a worse prognosis. Laboratory experiments confirmed bioinformatic findings. MT1X was also found to be an independent prognostic biomarker for ccRCC and is involved in immune system regulation.

Early Low-Fluence Red Light or Darkness Modulates the Shoot Regeneration Capacity of Excised Arabidopsis Roots.

In plants, light is an important environmental signal that induces meristem development and interacts with endogenous signals, including hormones. We found that treatment with 24 h of low-fluence red light (24 h R) or 24 h of darkness (24 h D) following root excision greatly increased the frequency of shoot generation, while continuous low-fluence red light in callus and shoot induction stages blocked the explants' ability to generate shoots. Shoot generation ability was closely associated with WUS expression and distribution pattern. 1-N-naphthylphtalamic acid (NPA) disrupted the dynamic distribution of the WUS signal induced by early 24 h R treatment, and NPA plus 24 R treatment increased the average shoot number compared with early 24 h R alone. Transcriptome analysis revealed that differentially expressed genes involved in meristem development and hormone signal pathways were significantly enriched during 24 R or 24 D induced shoot regeneration, where early 24 h R or 24 h D treatment upregulated expression of WOX5, LBD16, LBD18 and PLT3 to promote callus initiation and formation of root primordia, and also activated WUS, STM, CUC1 and CUC2 expression, leading to initiation of the shoot apical meristem (SAM). This finding demonstrates that early exposure of explants to transient low-fluence red light or darkness modulates the expression of marker genes related with callus development and shoot regeneration, and dynamic distribution of WUS, leading to an increased ability to generate shoots.

The application of histone deacetylases inhibitors in glioblastoma.

The epigenetic abnormality is generally accepted as the key to cancer initiation. Epigenetics that ensure the somatic inheritance of differentiated state is defined as a crucial factor influencing malignant phenotype without altering genotype. Histone modification is one such alteration playing an essential role in tumor formation, progression, and resistance to treatment. Notably, changes in histone acetylation have been strongly linked to gene expression, cell cycle, and carcinogenesis. The balance of two types of enzyme, histone acetyltransferases (HATs) and histone deacetylases (HDACs), determines the stage of histone acetylation and then the architecture of chromatin. Changes in chromatin structure result in transcriptional dysregulation of genes that are involved in cell-cycle progression, differentiation, apoptosis, and so on. Recently, HDAC inhibitors (HDACis) are identified as novel agents to keep this balance, leading to numerous researches on it for more effective strategies against cancers, including glioblastoma (GBM). This review elaborated influences on gene expression and tumorigenesis by acetylation and the antitumor mechanism of HDACis. Besdes, we outlined the preclinical and clinical advancement of HDACis in GBM as monotherapies and combination therapies.

Anti-tumour activity of zinc ionophore pyrithione in human ovarian cancer cells through inhibition of proliferation and migration and promotion of lysosome-mitochondrial apoptosis.

Zinc pyrithione (ZPT) is widely used as an antimicrobial. Zinc is a necessary trace element of the human whose homeostasis associated with several cancers. However, the anticancer effect of increased Zinc in ovarian cancer is still unclear. This study focussed on the anti-tumour effects of ZPT combined with Zinc in SKOV3 and SKOV3/DDP cells. The cell viability, apoptosis, migration, and invasion assays were detected by CCK-8, flow cytometry, wound healing and transwell assay, respectively. The distribution of Zinc in cells was monitored by staining of Zinc fluorescent dye and lysosome tracker. The changes in lysosomal membrane stability were reflected by acridine orange fluorescence and cathepsin D reposition. Expression of the proteins about invasion and apoptosis was evaluated by western blot. The results indicated that ZPT combined with Zinc could notably reduce cell viability, inhibit migration and invasion in SKOV3 and SKOV3/DDP cells. Besides, ZPT performed as a Zinc carrier targeted lysosomes, caused the increase of its membrane permeability and the release of cathepsin D accompanied by mitochondrial apoptosis in SKOV3/DDP cells. In conclusion, our work suggests that ZPT combined with Zinc could inhibit proliferation, migration, invasion, and promote apoptosis by trigger the lysosome-mitochondrial apoptosis pathway in ovarian carcinoma.

GhTIE1 Regulates Branching Through Modulating the Transcriptional Activity of TCPs in Cotton and Arabidopsis.

Transcription factors (TFs) and transcriptional regulators are important switches in transcriptional networks. In recent years, the transcriptional regulator TIE1 (TCP interactor containing EAR motif protein 1) was identified as a nuclear transcriptional repressor which regulates leaf development and controls branch development. However, the function and regulatory network of GhTIE1 has not been studied in cotton. Here, we demonstrated that GhTIE1 is functionally conserved in controlling shoot branching in cotton and Arabidopsis. Overexpression of GhTIE1 in Arabidopsis leads to higher bud vigor and more branches, while silencing GhTIE1 in cotton reduced bud activity and increased branching inhibition. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that GhTIE1 directly interacted with subclass II TCPs (GhBRC1, GhBRC2, and GhTCP13) in vivo and in vitro. Overexpression of GhBRC1, GhBRC2, and GhTCP13 in mutant brc1-2 partially rescued the mutant phenotype and decreased the number of branches, showing that these TCPs are functionally redundant in controlling branching. A transient dual-luciferase reporter assay indicated that GhTIE1 repressed the protein activity of GhBRC1 and GhTCP13, and thereby decreased the expression of their target gene GhHB21. Gene expression level analysis in GhTIE1-overexpressed and silenced plants also proved that GhTIE1 regulated shoot branching via repressing the activity of BRC1, HB21, HB40, and HB53. Our data reveals that shoot branching can be controlled via modulation of the activity of the TIE1 and TCP proteins and provides a theoretical basis for cultivating cotton varieties with ideal plant types.

Over-expression of an R2R3 MYB Gene, GhMYB73, increases tolerance to salt stress in transgenic Arabidopsis.

MYB family genes act as important regulators modulating the response to abiotic stress in plants. However, much less is known about MYB proteins in cotton. Here, we found that a cotton MYB gene, GhMYB73, was induced by NaCl and abscisic acid (ABA). Silencing GhMYB73 expression in cotton increased sensitivity to salt stress. The cotyledon greening rate of Arabidopsis thaliana over-expressing GhMYB73 under NaCl or mannitol treatment was significantly enhanced during the seedling germination stage. What's more, several osmotic stress-induced genes, such as AtNHX1, AtSOS3 and AtP5CS1, were more highly induced in the over-expression lines than in wild type under salt treatment, supporting the hypothesis that GhMYB73 contributes to salinity tolerance by improving osmotic stress resistance. Arabidopsis lines over-expressing GhMYB73 had superior germination and cotyledon greening under ABA treatment, and some abiotic stress-induced genes involved in ABA pathways (AtPYL8, AtABF3, AtRD29B and AtABI5), had increased transcription levels under salt-stress conditions in these lines. Furthermore, we found that GhMYB73 physically interacts with GhPYL8 and AtPYL8, suggesting that GhMYB73 regulates ABA signaling during salinity stress response. Taken together, over-expression of GhMYB73 significantly increases tolerance to salt and ABA stress, indicating that it can potentially be used in transgenic technology approaches to improve cotton salt tolerance.

NorB, an efflux pump in Staphylococcus aureus strain MW2, contributes to bacterial fitness in abscesses.

While remaining a major problem in hospitals, Staphylococcus aureus is now spreading in communities. Strain MW2 (USA400 lineage) and other community methicillin-resistant S. aureus strains most commonly cause skin infections with abscess formation. Multidrug resistance (MDR) efflux pumps contribute to antimicrobial resistance but may also contribute to bacterial survival by removal of environmental toxins. In S. aureus, NorA, NorB, NorC, and Tet38 are chromosomally encoded efflux pumps whose overexpression can confer MDR to quinolones and other compounds (Nor pumps) or tetracyclines alone (Tet38), but the natural substrates of these pumps are not known. To determine the role of these efflux pumps in a natural environment in the absence of antibiotics, we used strain MW2 in a mouse subcutaneous abscess model and compared pump gene expression as determined by reverse transcription-PCR in the abscesses and in vitro. norB and tet38 were selectively upregulated in vivo more than 171- and 24-fold, respectively, whereas norA and norC were downregulated. These changes were associated with an increase in expression of mgrA, which encodes a transcriptional regulator known to affect pump gene expression. In competition experiments using equal inocula of a norB or tet38 mutant and parent strain MW2, each mutant exhibited growth defects of about two- to threefold in vivo. In complementation experiments, a single-copy insertion of norB (but not a single-copy insertion of tet38) in the attB site within geh restored the growth fitness of the norB mutant in vivo. Our findings indicate that some MDR pumps, like NorB, can facilitate bacterial survival when they are overexpressed in a staphylococcal abscess and may contribute to the relative resistance of abscesses to antimicrobial therapy, thus linking bacterial fitness and resistance in vivo.

Posttranslational modification influences the effects of MgrA on norA expression in Staphylococcus aureus.

MgrA is a global regulator in Staphylococcus aureus. Differences in the effects of MgrA on norA expression have been reported for different strains, which varied in rsbU, a gene that affects the expression of sigB, which encodes an alternative sigma factor involved in stress responses. We hypothesized that MgrA was modified by sigB-dependent factors that affected its ability to control the expression of the norA efflux pump. Heterologously expressed MgrA purified from Escherichia coli was incubated with crude extracts (CE) from strains RN6390 (rsbU) and SH1000 (rsbU(+)) and tested for binding to the norA promoter. Purified MgrA exhibited greater binding to norA promoter DNA after being incubated with SH1000 CE than MgrA incubated with the RN6390 CE. Phosphorylation of MgrA occurring in cell extracts caused it to lose the ability to bind norA promoter DNA. Overexpression of pknB, encoding a candidate serine/threonine kinase, produced increased phospho-MgrA and led to a fivefold increase in the transcript level of norA for both RN6390 and SH1000, as well as a fourfold increase in the MICs of norfloxacin and ciprofloxacin for these two strains. The levels of expression of pknB in RN6390 and SH1000, however, indicated that additional factors related to rsbU or sigB contribute to the differential regulatory effects of MgrA on norA expression.

Effects of GhWUS from upland cotton (Gossypium hirsutum L.) on somatic embryogenesis and shoot regeneration.

The WUSCHEL (WUS) gene encodes a plant-specific homeodomain-containing transcriptional regulator, which plays important roles during embryogenesis, as well as in the formation of shoot and flower meristems. Here, we isolated two homologues of Arabidopsis thaliana WUS (AtWUS), GhWUS1a_At and GhWUS1b_At, from upland cotton (Gossypium hirsutum). Domain analysis suggested that the two putative GhWUS proteins contained a highly conserved DNA-binding HOX domain and a WUS-box. Expression profile analysis showed that GhWUSs were predominantly expressed during the embryoid stage. Ectopic expression of GhWUSs in Arabidopsis could induce somatic embryo and shoot formation from seedling root tips. Furthermore, in the absence of exogenous hormone, overexpression of GhWUSs in Arabidopsis could promote shoot regeneration from excised roots, and in the presence of exogenous auxin, excised roots expressing GhWUS could be induced to produce somatic embryo. In addition, expression of the chimeric GhWUS repressor in cotton callus inhibited embryogenic callus formation. Our results show that GhWUS is an important regulator of somatic embryogenesis and shoot regeneration.

Regulators of expression of the oligopeptide permease A proteins of Borrelia burgdorferi.

Borrelia burgdorferi undergoes an infectious cycle that requires adaptation to different hosts and marked differences in environment. B. burgdorferi copes with its different environments by regulating the expression of proteins required for survival in specific settings. The B. burgdorferi oligopeptide permease (Opp) is one of only a few transporters encoded by the B. burgdorferi genome. Opp proteins in other bacteria serve multiple environmental adaptation functions. B. burgdorferi appears to broaden the usage of this transporter by utilizing five different substrate binding proteins (OppA proteins) that interact with the integral membrane components of the transporter. Expression of the OppA proteins is individually regulated and may play different roles in adaptation to host environments. Very little is known about the mechanisms used by B. burgdorferi to regulate the expression of different OppA proteins. Here we show that the alternative sigma factors, RpoS and RpoN, regulate the expression of oppA5 but not that of other oppA genes. Using a reporter assay with Escherichia coli and gel shift binding assays, we also show that the B. burgdorferi BosR/Fur homologue interacts with the oppA4 promoter and that another candidate transcription factor, EbfC, interacts with the oppA5 promoter. Binding to the promoters was confirmed by gel shift assays. Expression of BosR/Fur in its different hosts does appear to parallel the expression of oppA4. A better understanding of the factors involved in gene regulation in B. burgdorferi will help to identify coregulated proteins that may cooperate to allow the organism to survive in a specific environment.

Characterization of the small untranslated RNA RyhB and its regulon in Vibrio cholerae.

Numerous small untranslated RNAs (sRNAs) have been identified in Escherichia coli in recent years, and their roles are gradually being defined. However, few of these sRNAs appear to be conserved in Vibrio cholerae, and both identification and characterization of sRNAs in V. cholerae remain at a preliminary stage. We have characterized one of the few sRNAs conserved between E. coli and V. cholerae: RyhB. Sequence conservation is limited to the central region of the gene, and RyhB in V. cholerae is significantly larger than in E. coli. As in E. coli, V. cholerae RyhB is regulated by the iron-dependent repressor Fur, and it interacts with the RNA-binding protein Hfq. The regulons controlled by RyhB in V. cholerae and E. coli appear to differ, although some overlap is evident. Analysis of gene expression in V. cholerae in the absence of RyhB suggests that the role of this sRNA is not limited to control of iron utilization. Quantitation of RyhB expression in the suckling mouse intestine suggests that iron availability is not limiting in this environment, and RyhB is not required for colonization of this mammalian host by V. cholerae.

HIV infection and sexually transmitted diseases in female commercial sex workers in China.

A cross-sectional survey was conducted among female commercial sex workers (FSWs) in Zhengzhou, China, to estimate rates of HIV infection and sexually transmitted diseases (STDs) and to document their sexual behavior patterns from October 2000 to January 2001. FSWs were recruited by the snowball sampling technique and were interviewed at their working environments anonymously. This strategy resulted in high rates of response (92%) and concordance (98%) to sensitive questions. A total of 621 FSWs were enrolled. One direct FSW and 1 indirect FSW were positive for antibodies to HIV in oral fluids (prevalence of HIV infection, 1.4% and 0.2%, respectively). A history of STDs was reported by 49% of the FSWs. Most FSWs (87%) reported inconsistent condom use. Ten percent of FSWs recognized their clients as drug users. A few FSWs (2.2%) were injecting drug users, of whom 2 reported incidents of sharing needles/syringes with other injecting drug users. Direct FSWs had more risk characteristics and were more vulnerable to HIV infection and STDs than indirect FSWs. Inconsistent use of condoms and a high level of STDs underscore the urgent need to implement intervention strategies and condom promotion, particularly among direct sex workers in China.

Deletion of a Vibrio cholerae ClC channel results in acid sensitivity and enhanced intestinal colonization.

ClC chloride channels are found in all three kingdoms of life though little is known about their functions in prokaryotes. Here we investigated the role of a Vibrio cholerae ClC channel in acid resistance and intestinal colonization. The putative V. cholerae ClC channel was found to confer mild resistance to acid when pH was adjusted with HCl, but not with other acids. Surprisingly, a ClC channel deletion mutant exhibited enhanced intestinal colonization in infant mice.