Outer membrane vesicles generated by an exogenous bacteriophage lysin and protection against Acinetobacter baumannii infection.

BACKGROUND: The outer membrane vesicles (OMVs) produced by Gram-negative bacteria can modulate the immune system and have great potentials for bacterial vaccine development. RESULTS: A highly active Acinetobacter baumannii phage lysin, LysP53, can stimulate the production of OMVs after interacting with A. baumannii, Escherichia coli, and Salmonella. The OMVs prepared by the lysin (LOMVs) from A. baumannii showed better homogeneity, higher protein yield, lower endotoxin content, and lower cytotoxicity compared to the naturally produced OMVs (nOMVs). The LOMVs contain a significantly higher number of cytoplasmic and cytoplasmic membrane proteins but a smaller number of periplasmic and extracellular proteins compared to nOMVs. Intramuscular immunization with either LOMVs or nOMVs three times provided robust protection against A. baumannii infections in both pneumonia and bacteremia mouse models. Intranasal immunization offered good protection in the pneumonia model but weaker protection (20-40%) in the bacteremia model. However, with a single immunization, LOMVs demonstrated better protection than the nOMVs in the pneumonia mouse model. CONCLUSIONS: The novel lysin approach provides a superior choice compared to current methods for OMV production, especially for vaccine development.

Butorphanol inhibits androgen biosynthesis and metabolism in rat immature Leydig cells in vitro.

Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. The objective of this study was to investigate the influence of butorphanol on androgen secretion by rat Leydig cells isolated from the 35-day-old male rats. Rat Leydig cells were cultured with 0.5-50 µM butorphanol for 3 h in vitro. Butorphanol at 5 and 50 µM significantly inhibited androgen secretion in immature Leydig cells. At 50 µM, butorphanol also blocked the effects of luteinizing hormone (LH) and 8bromo-cAMP-stimulated androgen secretion and 22R-hydroxycholesterol- and pregnenolone-mediated androgen production. Further analysis of the results showed that butorphanol downregulated the expression of genes involved in androgen production, including Lhcgr (LH receptor), Cyp11a1 (cholesterol side-chain cleavage enzyme), Srd5a1 (5α-reductase 1), and Akr1c14 (3α-hydroxysteroid dehydrogenase). Additionally, butorphanol directly inhibited HSD3B1 (3ß-hydroxysteroid dehydrogenase 1) and SRD5A1 activity. In conclusion, butorphanol may have side effects of inhibiting androgen biosynthesis and metabolism in Leydig cells.

Rh(III)-catalyzed [4 + 1] cyclization of aryl substituted pyrazoles with cyclopropanols via C-H activation.

A rhodium-catalyzed formal [4 + 1]-cyclization reaction of aryl substituted pyrazoles with cyclopropanols via C-H bond activation/cyclization processes to selectively construct a series of carbonyl functionalized pyrazolo[5,1-a]isoindoles is described. The reaction features good functional group compatibility and a broad substrate scope with respect to both cyclization components with up to 84% yields. Mechanistic studies indicated that the C-H cleavage might be the rate-determining step in this transformation.

LysP53 activity against Salmonella and its application in decontamination of Salmonella on fresh romaine lettuce.

Salmonella is a zoonotic pathogen that is commonly associated with foodborne disease outbreaks. This study found that a newly identified Gram-negative lysin LysP53 had good activity against a wide range of Salmonella, including Salmonella Newington, Salmonella Typhimurium, and Salmonella Dublin. Without the help of an outer membrane permeabilizer, 4 µM LysP53 could reduce 97.6% of planktonic Salmonella Enteritidis and 90% of the bacteria in biofilms. Moreover, LysP53 was highly thermostable because it maintained >90% activity even after exposure to temperatures up to 95 °C. Although high concentrations of salts could reduce the activity, LysP53 was found safe for oral gavage of mice without affecting body weights and cytokines in sera and able to reduce 90% of Salmonella Enteritidis loads on fresh romaine lettuce after 30 min of treatment. Because of its good activity against a wide range of bacteria, thermal stability, safe for oral administration, LysP53 could be used as a biocontrol agent for reducing bacterial loads in fresh vegetable food. KEY POINTS: • Lysin LysP53 has high bactericidal activity against Salmonella. • LysP53 is thermostable even at high temperature of up to 95 °C. • LysP53 can be used for topical decontamination of Salmonella on vegetables.

Carbon Dots Mediated In Situ Confined Growth of Bi Clusters on g-C3 N4 Nanomeshes for Boosting Plasma-Assisted Photoreduction of CO2.

Synthesis of high-efficiency, cost-effective, and stable photocatalysts has long been a priority for sustainable photocatalytic CO2 reduction reactions (CRR), given its importance in achieving carbon neutrality goals under the new development philosophy. Fundamentally, the sluggish interface charge transportation and poor selectivity of products remain a challenge in the CRR progress. Herein, this work unveils a synergistic effect between high-density monodispersed Bi/carbon dots (CDs) and ultrathin graphite phase carbon nitride (g-C3 N4 ) nanomeshes for plasma-assisted photocatalytic CRR. The optimal g-C3 N4 /Bi/CDs heterojunction displays a high selectivity of 98% for CO production with a yield up to 22.7 µmol g-1 without any sacrificial agent. The in situ confined growth of plasmonic Bi clusters favors the production of more hot carriers and improves the conductivity of g-C3 N4 . Meanwhile, a built-in electric field driving force modulates the directional injection photogenerated holes from plasmonic Bi clusters and g-C3 N4 photosensitive units to adjacent CDs reservoirs, thus promoting the rapid separation and oriented transfer in the CRR process. This work sheds light on the mechanism of plasma-assisted photocatalytic CRR and provides a pathway for designing highly efficient plasma-involved photocatalysts.

Rhodium(III)-Catalyzed Sequential Cyclization of N-Boc Hydrazones with Propargylic Monofluoroalkynes via C-H Activation/C-F Cleavage for the Synthesis of Spiro[cyclobutane-1,9'-indeno[1,2-a]indenes].

An effective rhodium(III) catalysis for the construction of valuable tetracyclic compounds is described herein. This domino process involving the C-H activation/[3 + 2] annulation/intramolecular Friedel-Crafts reaction sequences of simple and readily available N-Boc hydrazones and propargylic monofluoroalkynes afforded fused tetracyclic spiro[cyclobutane-1,9'-indeno[1,2-a]indenes] in moderate to good yields, featuring three C-C bond formation. Moreover, control experiments indicated that the C-H activation might be involved in the rate-determining step.

Chlamydia infection, PID, and infertility: further evidence from a case-control study in China.

BACKGROUND: Chlamydia trachomatis infection and pelvic inflammatory disease (PID) are well-known risk factors for female infertility. But there is limited evidence from China. This study aimed to further explore the associations between previous/current chlamydial infection, PID, and infertility in China. METHODS: We performed a 1:2 matched case-control study with two control groups: pregnant controls and non-pregnant controls in China in 2019. Women diagnosed with infertility were selected as cases (n = 255). Controls were selected based on the following criteria: Pregnant women who were documented in the selected hospitals were chosen as Pregnant controls (n = 510), and people who sought health care in Obstetric/Gynecologic clinics, Family Planning clinics, Dermatology and STD Department or Urological department were selected as Non-pregnant controls (n = 510). Infertility induced by male factors and people who used antibiotics in the vagina within two weeks were excluded. The first-stream specimen of urine samples was tested for chlamydia by nucleic acid amplification testing (NAAT). Conditional logistic regression was used to estimate the association. RESULTS: The prevalence of previous chlamydial infection and PID were significantly higher in cases (2.4%, 17.3%) than in controls (Non-pregnancy: 0.4%, 3.0%; Pregnancy: 0.4%, 9.0%). The current chlamydial infection rates were 5.9%, 7.3%, and 7.1% in infertile, pregnant, and non-pregnant women, respectively. After adjusting for confounders, PID largely elevated the risk of infertility (using non-pregnant controls: adjusted OR = 2.57, 95% CI 1.51, 4.39; using pregnant controls: adjusted OR = 6.83, 95% CI 3.47, 13.43). And the positive association between PID and tubal infertility was more obvious for both groups. For current chlamydial infection, none of the odds ratios were significant at the 0.05 level, while small sample size limited the evaluation of an association between prior chlamydial infection with infertility. CONCLUSIONS: Previous PID was indicated to largely increase the risk of infertility, especially tubal infertility. And there should be continuing emphasis on highly sensitive and specific biomarker for prior chlamydial infection.

RNase II binds to RNase E and modulates its endoribonucleolytic activity in the cyanobacterium Anabaena PCC 7120.

In Escherichia coli, the endoribonuclease E (RNase E) can recruit several other ribonucleases and regulatory proteins via its noncatalytic domain to form an RNA degradosome that controls cellular RNA turnover. Similar RNA degradation complexes have been found in other bacteria; however, their compositions are varied among different bacterial species. In cyanobacteria, only the exoribonuclease PNPase was shown to bind to the noncatalytic domain of RNase E. Here, we showed that Alr1240, a member of the RNB family of exoribonucleases, could be co-isolated with RNase E from the lysate of the cyanobacterium Anabaena PCC 7120. Enzymatic analysis revealed that Alr1240 is an exoribonuclease II (RNase II), as it only degrades non-structured single-stranded RNA substrates. In contrast to known RNase E-interacting ribonucleases, which bind to the noncatalytic domain of RNase E, the Anabaena RNase II was shown to associate with the catalytic domain of RNase E. Using a strain in which RNase E and RNase II were tagged in situ with GFP and BFP, respectively, we showed that RNase E and RNase II form a compact complex in vivo by a fluorescence resonance energy transfer (FRET) assay. RNase E activity on several synthetic substrates was boosted in the presence of RNase II, suggesting that the activity of RNase E could be regulated by RNase II-RNase E interaction. To our knowledge, Anabaena RNase II is an unusual ribonuclease that interacts with the catalytic domain of RNase E, and it may represent a new type of RNA degradosome and a novel mechanism for regulating the activity of the RNA degradosome. As Anabaena RNase E interacts with RNase II and PNPase via different regions, it is very likely that the three ribonucleases form a large complex and cooperatively regulate RNA metabolism in the cell.

Potential occupational exposure of parents to endocrine disrupting chemicals, adverse birth outcomes, and the modification effects of multi-vitamins supplement and infant sex.

BACKGROUND: Maternal occupational exposure to endocrine disrupting chemicals (EDCs) may have adverse effect on birth outcomes. However, little is known about paternal EDCs exposure and the combined effect of parental exposure on birth outcomes. OBJECTIVES: To assess the effects of both maternal and paternal occupational EDCs exposure on adverse birth outcomes, and further explore if multi-vitamins supplement and infant sex modify the association. METHODS: We conducted a prospective cohort study of 5421 mother-father-newborn groups in Guangzhou, China. A questionnaire informed by a job exposure matrix (JEM) was applied to collect parental occupational EDCs exposure based on the type of work performed. We used logistic regression to estimate association between parental EDCs exposure and birth outcomes (including preterm birth (PTB), low birth weight (LBW), birth defects and congenital heart defects (CHD)). Stratified analyses and Cochran Q tests were performed to assess the modifying effect of maternal multi-vitamins supplement use and infant sex. RESULTS: Compared with mothers unexposed, we found that mothers those exposed to EDCs were associated with increased odds of birth defects (aOR=1.70, 95% confidence interval (CI): 1.10-2.62), especially for those exposed for > 1.5 years (aOR= 3.00, 95% CIs: 1.78-5.03), or those with directly occupational exposed to EDCs (aOR= 2.94, 95% CIs: 1.72-5.04). Maternal exposure for > 1.5 years and direct exposure increased the risk of CHD, with aORs of 2.47 (1.21-5.02) and 2.79 (1.37-5.69), respectively. Stronger adverse effects were also observed when mothers and fathers were both exposed to EDCs. Paternal occupational EDCs exposure and exposure ≤ 1.5 years was associated with increased odds of LBW, with aORs of 2.14 (1.63-2.79) and 1.54 (1.10-2.15), respectively. When stratified by multi-vitamins supplement and infant sex, we observed slightly stronger effects for maternal exposure on birth defects/CHD as well as paternal EDCs exposure on PTB and LBW, among those without multi-vitamins supplement and among male babies, although the modification effects were not significant. CONCLUSION: Maternal exposure to EDCs was associated with greater odds of birth defects and CHD, while paternal exposure was mainly associated with greater odds of LBW. These effects tend to be stronger among mothers without multi-vitamins supplement and among male babies.

Perfluoroundecanoic acid inhibits Leydig cell development in pubertal male rats via inducing oxidative stress and autophagy.

Perfluoroundecanoic acid (PFUnA) is one of long-chain perfluoroalkyl carboxylic acids. However, the effect of PFUnA on pubertal development of Leydig cells remains unclear. The goal of this study was to investigate the effect of PFUnA on Leydig cell development in pubertal male rats. We orally dosed male Sprague-Dawley rats (age 35 days) with PFUnA at doses of 0, 1, 5, and 10 mg/kg/day from postnatal day (PND) 35 to PND 56. Serum testosterone and luteinizing hormone levels were remarkably reduced by PFUnA at ≥1 mg/kg while serum follicle-stimulating hormone levels were lowered at 5 and 10 mg/kg. PFUnA down-regulated the expression of Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, Hsd11b1, Insl3, Nr5a1, Fshr, Dhh, Sod1, and Sod2 and their proteins in the testis and the expression of Lhb and Fshb in the pituitary. PFUnA reduced Leydig cell number at 5 and 10 mg/kg. PFUnA induced oxidative stress and increased autophagy. These may result from the inhibition of phosphorylation of mTOR, AKT1, AKT2, and ERK1/2 in the testis. In conclusion, PFUnA exhibits inhibitory effects on pubertal Leydig cell development possibly via inducing oxidative stress and increasing autophagy.

Perfluorotridecanoic Acid Inhibits Leydig Cell Maturation in Male Rats in Late Puberty via Changing Testicular Lipid Component.

Perfluorotridecanoic acid (PFTrDA) is a long-chain (C13) perfluoroalkyl carboxylic acid. Here, we report the influence of PFTrDA exposure on the maturation of rat Leydig cells in late puberty in vivo. Male Sprague-Dawley rats were administered PFTrDA by gavage of 0, 1, 5, and 10 mg/kg/day from 35 days to 56 days postpartum. PFTrDA had no effect on body weight, testis weight, and epididymis weight. It significantly decreased the serum testosterone level after 5 and 10 mg/kg exposure, while it did not alter the serum estradiol level. The serum luteinizing hormone level was markedly reduced after 10 mg/kg PFTrDA exposure, while the follicle-stimulating hormone level was unchanged. Star, Cyp11a1, Cyp17a1, Hsd3b1, and Insl3 transcript levels in the testis were markedly lowered in the 1-5 mg/kg PFTrDA group and the Lhb transcript level in the pituitary in the 10 mg/kg group. CYP11A1 and HSD11B1-positive Leydig cell numbers were markedly reduced after 10 mg/kg PFTrDA exposure. Testicular triglyceride and free fatty acid (palmitic acid, oleic acid, and linoleic acid) levels were significantly reduced by PFTrDA, while Mgll (up-regulation) and Scarb1 and Elovl5 (down-regulation) expression were altered. AKT1 and AMPK phosphorylation was stimulated after 10 PFTrDA mg/kg exposure. In conclusion, PFTrDA delays the maturation of Leydig cells in late puberty mainly by altering the free fatty acid profile.

Temperature variation and preterm birth among live singleton deliveries in Shenzhen, China: A time-to-event analysis.

OBJECTIVE: Ambient temperature extremes due to heat exposure was an established risk factor for preterm birth (<37 gestational weeks). However, there is insufficient epidemiological evidence on the effects of temperature variation(TV), although TV is also associated with heat exposure and can influence human health risk. This study aimed to investigate the relationship between inter- and intraday TV and preterm birth (PTB). METHOD: A total of 1,388,994 live singleton births were collected from January 2003 to December 2012, from the Shenzhen Birth registry system. Daily temperature range (DTR) was defined as the difference between the highest and lowest recorded daily temperature. Intraday TV was defined as the maximum daily diurnal temperature range in a given week (Max-DTR). Inter-day TV was defined as the maximum increase or decrease in daily mean temperature between days t and t-1in a given week; either an increase (Temp-inc) or a decrease (Temp-dec). We used Cox proportional hazards models to estimate TV-related PTB risks during the first trimester, the second trimester, and in late pregnancy. RESULTS: The maximum values for DTR, Temp-inc, and Temp-dec were 17 °C, 8 °C and 11 °C, respectively. The greatest TV-related PTB risk occurred in the second trimester, with 5.8% (95%CI: 3.3%, 8.3%), 23.7% (95%CI: 19.6%, 27.9%), and 4.4% (95%CI: 1.8%, 7.1%) differences per 1 °C increase in Max-DTR, Temp-inc, and Temp-dec, respectively. Greater TV was associated with elevated PTB risk during the warm season. The association between TV and PTB was modified by seasons, maternal education and chronic conditions. CONCLUSIONS: Sharp TV is a likely risk factor for PTB. Policy makers and clinicians should recognize the potential role of TV in the etiology of PTB so that interventions can be designed to protect pregnant women and their fetuses against extreme temperatures.

Perfluorotridecanoic acid inhibits fetal Leydig cell differentiation after in utero exposure in rats via increasing oxidative stress and autophagy.

Perfluorotridecanoic acid (PFTrDA) is a long-chain perfluoroalkyl substance, and its effect on the differentiation of fetal Leydig cells remains unclear. The objective of this study is to explore the effect of in utero PFTrDA exposure on the differentiation of fetal Leydig cells and investigate its underlying mechanisms. Pregnant Sprague-Dawley female rats were daily administered by gavage of PFTrDA at doses of 0, 1, 5, and 10 mg/kg from gestational day 14 to 21. PFTrDA had no effect on the body weight of dams, but significantly reduced the body weight and anogenital distance of male pups at birth at a dose of 10 mg/kg. PFTrDA significantly decreased serum testosterone levels as low as 1 mg/kg. PFTrDA did not affect fetal Leydig cell number, but promoted abnormal aggregation of fetal Leydig cells at doses of 5 and 10 mg/kg. PFTrDA down-regulated the expression of Insl3, Lhcgr, Scarb1, Star, Hsd3b1, Cyp17a1, Nr5a1, and Dhh as well as their proteins. PFTrDA lowered the levels of antioxidants (SOD1, CAT, and GPX1), induced autophagy as shown by increased levels of LC3II and beclin1, and reduced the phosphorylation of mTOR. In conclusion, PFTrDA inhibits the differentiation of fetal Leydig cells in male pups after in utero exposure mainly through increasing oxidative stress and inducing autophagy.

Characterization of Pathogenicity-Associated V2 Protein of Tobacco Curly Shoot Virus.

V2 proteins encoded by some whitefly-transmitted geminiviruses were reported to be functionally important proteins. However, the functions of the V2 protein of tobacco curly shoot virus (TbCSV), a monopartite begomovirus that causes leaf curl disease on tomato and tobacco in China, remains to be characterized. In our report, an Agrobacterium infiltration-mediated transient expression assay indicated that TbCSV V2 can suppress local and systemic RNA silencing and the deletion analyses demonstrated that the amino acid region 1-92 of V2, including the five predicted α-helices, are required for local RNA silencing suppression. Site-directed substitutions showed that the conserved basic and ring-structured amino acids in TbCSV V2 are critical for its suppressor activity. Potato virus X-mediated heteroexpression of TbCSV V2 in Nicotiana benthamiana induced hypersensitive response-like (HR-like) cell death and systemic necrosis in a manner independent of V2's suppressor activity. Furthermore, TbCSV infectious clone mutant with untranslated V2 protein (TbCSV∆V2) could not induce visual symptoms, and coinfection with betasatellite (TbCSB) could obviously elevate the viral accumulation and symptom development. Interestingly, symptom recovery occurred at 15 days postinoculation (dpi) and onward in TbCSV∆V2/TbCSB-inoculated plants. The presented work contributes to understanding the RNA silencing suppression activity of TbCSV V2 and extends our knowledge of the multifunctional role of begomovirus-encoded V2 proteins during viral infections.

Syphilis Self-testing: A Nationwide Pragmatic Study Among Men Who Have Sex With Men in China.

BACKGROUND: Syphilis self-testing may help expand syphilis testing among men who have sex with men (MSM). China has rapidly scaled up human immunodeficiency virus (HIV) self-testing, creating an opportunity for integrated syphilis self-testing. However, there is a limited literature on implementing syphilis self-testing. METHODS: A cross-sectional online survey was conducted among Chinese MSM in 2018. Participants completed a survey instrument including sociodemographic characteristics, sexual behaviors, syphilis self-testing, and HIV self-testing history. Multivariable logistic regression was conducted to identify correlates of syphilis self-testing. We also recorded potential harms associated with syphilis self-testing. RESULTS: Six hundred ninety-nine MSM from 89 cities in 21 provinces in China completed the study. A total of 361/699 (51.7%) men tested for syphilis, of whom 174/699 (24.9%) men used syphilis self-testing. Among 174 who had self-tested, 90 (51.7%) reported that the self-test was their first syphilis test and 161 (92.5%) reported that they undertook syphilis self-testing together with HIV self-testing. After adjusting for covariates, syphilis self-testing was correlated with disclosure of sexual orientation to family or friends (adjusted odds ratio [aOR], 1.90; 95% confidence interval [CI], 1.32-2.73), reporting 2-5 male sexual partners (aOR, 1.81; 95% CI, 1.04-3.16), HIV self-testing (aOR, 39.90; 95% CI, 17.00-93.61), and never tested for syphilis in the hospital (aOR, 2.96; 95% CI, 1.86-4.72). Self-reported harms associated with syphilis self-testing were minimal. CONCLUSIONS: Scaling up syphilis self-testing could complement facility-based testing in China among MSM. Self-testing may increase first-time testing and has limited harms. Our findings suggest that syphilis self-testing could be integrated into HIV self-testing services.

Promoting routine syphilis screening among men who have sex with men in China: study protocol for a randomised controlled trial of syphilis self-testing and lottery incentive.

BACKGROUND: Men who have sex with men (MSM) bear a high burden of syphilis infection. Expanding syphilis testing to improve timely diagnosis and treatment is critical to improve syphilis control. However, syphilis testing rates remain low among MSM, particularly in low- and middle-income countries. We describe the protocol for a randomised controlled trial (RCT) to assess whether provision of syphilis self-testing services can increase the uptake of syphilis testing among MSM in China. METHODS: Four hundred forty-four high-risk MSM will be recruited online and randomized in a 1:1:1 ratio to (1) standard syphilis self-testing arm; (2) a self-testing arm program enhanced with crowdsourcing and a lottery-based incentive, and (3) a standard of care (control). Self-testing services include a free syphilis self-test kit through the mail at monthly intervals. Participants in the lottery incentive arm will additionally receive health promotion materials generated from an open crowdsourcing contest and be given a lottery draw with a 10% chance to win 100 RMB (approximately 15 US Dollars) upon confirmed completion of syphilis testing. Syphilis self-test kits have step-by-step instructions and an instructional video. This is a non-blinded, open-label, parallel RCT. Participants in each arm will be followed-up at three and 6 months through WeChat (a social media app like Facebook messenger). Confirmation of syphilis self-test use will be determined by requiring participants to submit a photo of the used test kit to study staff via secure data messaging. Both self-testing and facility-based testing will be ascertained by sending a secure photographic image of the completed kit through an existing digital platform. The primary outcome is the proportion of participants who tested for syphilis in the past 3 months. DISCUSSION: Findings from this study will provide much needed insight on the impact of syphilis self-testing on promoting routine syphilis screening among MSM. The findings will also contribute to our understanding of the safety, effectiveness and acceptability of syphilis self-testing. These findings will have important implications for self-testing policy, both in China and internationally. TRIAL REGISTRATION: ChiCTR1900022409 (10 April, 2019).

Interaction of Air Pollutants and Meteorological Factors on Birth Weight in Shenzhen, China.

BACKGROUND: This study aimed to assess if air pollutants and meteorological factors synergistically affect birth outcomes in Shenzhen, China. METHODS: A total of 1,206,158 singleton live births between 2005 and 2012 were identified from a birth registry database. Daily average measurements of particulate matter ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ambient air temperature (T), and dew point temperature (Td), a marker of humidity, were collected. Multivariable logistic regression models were used to evaluate associations between air pollution and small for gestational age (SGA), and full-term low birth weight (TLBW). We classified births into those conceived in the warm (May-October) and cold seasons (November-April) and then estimated interactions between air pollutants and meteorological factors. RESULTS: An interquartile range (IQR) increase in PM10 exposure during the first trimester (23.1 µg/m) and NO2 during both the first and second trimesters (15.1 and 13.4 µg/m) was associated with SGA and TLBW risk; odds ratios ranged from 1.01 (95% confidence interval [CI] = 1.00, 1.02) to 1.09 (1.07, 1.12). We observed interactive effects of both air temperature and humidity on PM10 and SGA for newborns conceived in the warm season. Each IQR increase in PM10 (11.1 µg/m) increased SGA risk by 90% (95% CI = 19%, 205%), 29% (23, 34%), 61% (10, 38%), and 26% (21, 32%) when T < 5th percentile, 5th < T < 95th percentile, Td < 5th percentile, and 5th < Td < 95th percentile, respectively. CONCLUSIONS: Our study found evidence of an interactive effect of air temperature and humidity on the relationship between PM10 exposure and SGA among newborns conceived in the warm season (May-October). Relatively low air temperature or humidity exacerbated the effects of PM10.

Temporal trends of preterm birth in Shenzhen, China: a retrospective study.

BACKGROUND: Preterm birth is the leading cause of child mortality under 5 years of age. Temporal trends in preterm birth rates are highly heterogeneous among countries and little information exists for China. To address this data gap, we investigated annual changes in preterm birth incidence rate and explored potential determinants of these changes in Shenzhen, China. METHODS: A total of 1.4 million live births, during 2003-2012, were included from the Shenzhen birth registry. Negative-binominal regression models were used to estimate the annual percent changes in incidence. To identify the potential determinants behind temporal trends, we estimated the contribution of each changing risk factor to changes in rate by calculating the difference in population-attributable risk fraction. RESULTS: Annual preterm birth incidence rates increased by 0.94% (95% CI 0.30%, 1.58%) overall, 3.60% (95% CI 2.73%, 4.48%) for medically induced, and 3.13% (95% CI 1.01%, 5.31%) for preterm premature rupture of membranes, but decreased by 2.34% (95% CI 1.62%, 3.06%) for spontaneous preterm labor. Higher maternal educational attainment (0.20 rate increase), lower proportion of inadequate prenatal care (0.15 rate reduction), more multipara (0.08 rate reduction), decreased proportion of preeclampsia or eclampsia (0.05 rate reduction), and larger proportion of young and older pregnant women (0.04 rate increase) were significant contributors to the overall change over time. Contributions of changing risk factors were different between preterm birth subtypes. CONCLUSIONS: Preterm birth rate in Shenzhen, China increased overall during 2003-2012, although trends varied across three preterm birth subtypes. The rising rates were associated with changes in maternal education and age.

Prevalence of depressive symptoms and its correlates among medical students in China: a national survey in 33 universities.

We conducted a national survey among medical students in China to estimate the prevalence of depressive symptoms and explore associated risk factors based on an established questionnaire composed of demographic information, life events in the past four weeks before survey, and the validated Chinese version of the 21-item Beck's Depression Inventory (BDI). The mean age of enrolled 9010 students was 20.7 (standard deviation: 1.6) years. BDI scores indicated that 19.9% had depressive symptoms based on the cut-off score of 14. Socioeconomic factors and student characteristics such as male sex, low monthly income per capita, father's poor education background, and higher year of study were associated with higher prevalence of depressive symptoms among medical students. Students who studied in comprehensive universities were more likely to have depressive symptoms compared with those from medical universities. Habitual smoking and alcohol drinking, sleep deprivation, and hospitalization or medication for one week or more in the last four weeks also predisposed students to higher risk of depressive symptoms. Our results indicate that depressive symptoms are becoming a highly prevalent health problem among Chinese medical students. Primary and secondary prevention should be prioritized to tackle this issue based on potential risk factors.

Corrigendum: Editorial: Chlamydia trachomatis infection: epidemiology, prevention, clinical, and basic science research.

[This corrects the article DOI: 10.3389/fpubh.2023.1167690.].