Optimal gestational weight gain in women with twin pregnancies and gestational diabetes mellitus: a population-based study in the United States.

BACKGROUND: There is limited evidence regarding optimal gestational weight gain in women with twin pregnancies and gestational diabetes mellitus. OBJECTIVE: This study aimed to examine the association between gestational weight gain and perinatal outcomes among women with gestational diabetes mellitus and twin pregnancies and to explore the gestational weight gain targets by prepregnancy body mass index category. STUDY DESIGN: A national population-based cohort study of twin pregnancies with gestational diabetes mellitus was conducted between 2014 and 2020. Women with gestational diabetes mellitus aged between 18 and 45 years with live-born twins without congenital malformations between 24 and 42 weeks of gestation were included in the analysis. Two approaches were used to determine the optimal gestational weight gain targets by body mass index category: an interquartile range method to calculate targets in low-risk gestational diabetes mellitus pregnancies and a logistic model method to identify the odds ratio targets at which a composite adverse outcome decreased. RESULTS: Of 29,308 women with gestational diabetes mellitus and twin pregnancies, 8239 (28.1%) were normal-weight, 7626 (26.0%) were overweight, and 13,443 (45.9%) were obese. The continuous standardized gestational weight gain by 36 weeks was associated with preterm birth <36 weeks, large-for-gestational-age infants, small-for-gestational-age infants, and gestational hypertensive disorders. The interquartile range targets were 13.6 to 20.9 kg, 10.9 to 20.4 kg, and 7.7 to 17.7 kg for normal-weight, overweight, and obese women, respectively. The odds ratio targets were 14.1 to 20.0 kg, 12.1 to 16.0 kg, and 6.1 to 12.0 kg for normal-weight, overweight, and obese women, respectively. Gestational weight gain outside these targets was associated with preterm birth <36 weeks, large-for-gestational-age and small-for-gestational-age infants, and gestational hypertensive disorders, and exhibited significant population attributable fractions for preterm birth <36 weeks, large-for-gestational-age infants, and gestational hypertensive disorders across body mass index categories. CONCLUSION: Compared with the Institute of Medicine guidelines, more stringent gestational weight gain targets would be beneficial for improved perinatal outcomes in women with gestational diabetes mellitus and twin pregnancies.

Perinatal outcomes among twin pregnancies with gestational diabetes mellitus: A nine-year retrospective cohort study.

Objective: To compare the outcomes between gestational diabetes mellitus (GDM) vs. non-GDM twin gestations. Methods: A retrospective cohort study of 2,151 twin pregnancies was performed in a tertiary hospital in Foshan, China, 2012-2020. Pregnancy and neonatal outcomes were compared between women with vs. without GDM using 1:1 propensity score matching (PSM) and multivariable logistic models. For neonatal outcomes, generalized estimating equation (GEE) approach was used to address the intertwin correlation. Results: Of the 2,151 participants, 472 women (21.9%) were diagnosed with GDM. Women with GDM were older and more likely to be overweight or obese, and more likely have chronic hypertension, assisted pregnancies and dichorionic twins. In the PSM cohort of 942 pregnancies, there was no statistical difference when comparing GDM twin pregnancies and non-GDM in any of the perinatal outcomes, especially in terms of preterm birth (PTB) <37 weeks (P = 0.715), large for gestational age (LGA) (P = 0.521) and neonatal respiratory distress (NRDS) (P = 0.206). In the entire cohort, no significant adjusted ORs for these outcomes were obtained from logistic regression models adjusted for confounders (aOR for PTB < 37 weeks: 1.25, 95% CI: 0.98-1.58; aOR for LGA: 1.26, 95% CI: 0.88-1.82; and aOR for NRDS, 1.05, 95% CI: 0.68-1.64). Conclusion: Twin pregnancies with GDM and adequate prenatal care have comparable perinatal outcomes to those without.

Association of Optimal Gestational Weight Gain Ranges With Perinatal Outcomes Across Body Mass Index Categories in Twin Pregnancies.

Importance: The existing gestational weight gain (GWG) recommendations for twin pregnancies are lacking for underweight individuals and are not stratified by obesity class. Objective: To identify optimal GWG ranges associated with reduced adverse perinatal outcomes stratified by prepregnancy body mass index (BMI) categories in twin pregnancies. Design, Setting and Participants: This population-based cohort study of twin pregnancies using data from the National Center for Health Statistics was conducted between January 1, 2014, and December 31, 2018. Statistical analysis was performed from October 24, 2021, to May 7, 2022. The study population comprised 262 604 individuals between 18 and 45 years of age with live-born twins without congenital malformation between 24 and 42 weeks of gestation. Two approaches were used to determine the optimal GWG ranges: a statistics-based approach calculating IQRs of GWG in a low-risk population, and an outcome-based approach identifying GWG thresholds below or above which an adverse perinatal outcome increased. Exposure: Gestational weight gain. Main Outcomes and Measures: Preterm birth less than 36 weeks, gestational hypertensive disorders, small for gestational age status, large for gestational age status, and a composite outcome defined as any occurrence of the individual outcomes. Results: The main sample comprised 200 810 individuals with twin pregnancies (mean [SD] maternal age, 30.4 [5.5] years; 1624 [0.8%] American Indian or Alaska Native, 13 031 [6.5%] Asian or Pacific Islander, 36 423 [18.1%] Black, and 149 732 [74.6%] White; and 137 409 [68.4%] multiparous). In the low-risk subgroup (n = 61 794), the IQRs of the total GWG after 36 weeks of gestation as assessed using a statistics-based approach and based on BMI group were 15.9 to 22.7 kg for underweight, 15.4 to 22.7 kg for normal weight, 12.7 to 22.2 kg for overweight, 10.0 to 20.0 kg for class 1 obesity, 7.7 to 18.1 kg for class 2 obesity, and 5.9 to 16.3 kg for class 3 obesity. The absolute risk of the composite outcome showed U-shaped associations with GWG across BMI categories. The optimal GWG ranges by 36 weeks identified using an outcome-based approach and BMI group were 17.5 to 24.9 kg for underweight, 15.0 to 24.9 kg for normal weight, 15.0 to 24.9 kg for overweight, 10.0 to 19.9 kg for class 1 obesity, 7.5 to 17.4 kg for class 2 obesity, and 5.0 to 9.9 kg for class 3 obesity. The multivariable logistic models assessed using the validation sample (n = 49 275) showed that GWG defined outside those optimal ranges was associated with preterm birth at less than 36 weeks, gestational hypertensive disorders, and small or large for gestational age. Conclusions and Relevance: This population-based cohort study found that optimal GWG ranges were similar for individuals with underweight and normal weight but decreased with increasing severity of obesity. The current US Institute of Medicine GWG recommendations may be too high for individuals with moderate or severe obesity.

Reineckia carnea Alleviates the Production of Inflammatory Cytokines and MUC5AC in Rats with Chronic Obstructive Pulmonary Disease.

Background: Reineckia carnea (RC), a perennial evergreen herb which belongs to Reineckia Kunth (Liliaceae), can be used for clearing the lungs and relieving cough, reducing phlegm and anti-inflammatory effects. Moreover, chronic obstructive pulmonary disease (COPD) is characterized by airway and lung inflammation and increased secretion of airway mucus. Therefore, RC has the potential to treat COPD. Methods: NR8383 cells were cultured and treated with various concentrations of RC (100 mg/mL, 10 mg/mL, 1 mg/mL, 100 µg/mL, 10 µg/mL, 1 µg/mL, 100 ng/mL, and 10 ng/mL). Cell viability and levels of interleukin (IL)-1ß, cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) in the cell culture supernatant or rat serum were analyzed using CCK-8 and enzyme-linked immunosorbent assay (ELISA), respectively. Sprague Dawley rats were assigned to mock, COPD model, RC (0.67 g/kg, 1.35 g/kg, and 2.7 g/kg), and ambroxol (5.4 mg/kg) groups. Western blot and quantitative polymerase chain reaction (qPCR) analyses were used to evaluate the protein and mRNA expression levels of mucin 5AC (MUC5AC) and Toll-like receptor 4 (TLR4). Results: The results showed that Reineckia carnea (RC) extract (RCE) inhibited the proliferation of NR8383 cells and suppressed the production of IL-1ß, PGE2, and COX-2 in NR8383 cells. Moreover, RCE decreased the levels of IL-1ß, PGE2, and COX-2 in the serum of rats with COPD and alleviated the expression of TLR4 and MUC5AC induced by COPD in rat lung tissue. Conclusion: RCE alleviated COPD by inhibiting the expression of COPD-induced inflammatory cytokines and MUC5AC in rats.

Association of serum vitamin D status with gestational diabetes mellitus and other laboratory parameters in early pregnant women.

BACKGROUND: The association between serum 25-hydroxy vitamin D (25(OH)D) status and gestational diabetes mellitus (GDM) gained attention in recent years, however the conclusion is still controversial due to many interfering factors, such as region of living, environment, lifestyle, and food supplements. Other metabolites (laboratory parameters) are also important in reflecting gestational states. This study aimed to investigate the association of serum 25(OH)D status in early pregnancy with GDM and other laboratory parameters in pregnant women. METHODS: A total of 1516 pregnant women whose blood glucose were normal before pregnancy in the city of Foshan in Guangdong, China were enrolled in this study. GDM was diagnosed between 24 to 28 weeks of pregnancy following the guidelines from the American Diabetes Association. Maternal serum 25(OH)D and other laboratory parameters-including hematology, coagulation, chemistry, and bone density-were measured utilizing various analytical methods in clinical laboratory at gestational weeks 11 to 14. RESULTS: The average 25(OH)D concentration was 59.1 ± 12.6 nmol/L. None of the study subjects had 25(OH)D < 25 nmol/L; 434 (28.6%) women had 25(OH)D deficiency (< 50 nmol/L), 882 women (58.2%) had 25(OH)D insufficiency (50-74 mmol/L) and 200 women (13.2%) had 25(OH)D sufficiency (≥ 75 nmol/L). There were 264 (17.4%) women diagnosed with GDM. There was not, however, an association between serum 25(OH)D in early pregnancy and GDM. Interestingly, women with more parity and high serum alkaline phosphatase levels had higher serum 25(OH)D levels. There was a possible positive association between serum 25(OH)D and pre-albumin, and a possible negative association between serum 25(OH)D, creatinine, and thrombin time. This study did not find an association between serum 25(OH)D and bone density. CONCLUSIONS: There were no associations between maternal serum 25(OH)D concentration in early pregnancy and the risk of GDM or bone density. There were, however, correlations between serum 25(OH)D and parity, seasoning at sampling, serum alkaline phosphatase, creatinine, pre-albumin, and coagulation factor thrombin time, which need further study to explain their pathophysiology and clinical significance.

Assessment of different thresholds of birthweight discordance for early neonatal outcomes: retrospective analysis of 2348 twin pregnancies.

BACKGROUND: The optimal threshold of birthweight discordance (BWD) remains controversial. This study aimed to evaluate the associations between BWD at different thresholds and early neonatal outcomes and to assess their predictive accuracy. METHODS: This was a retrospective cohort study using a birthweight data with the chorionicity information of 2348 liveborn twin pairs at a gestational age of ≥26 weeks, from 2012 to 2018. The percentage of BWD was calculated by dividing the actual birthweight difference by the weight of the larger twin and multiplying by 100. Outcomes of interest included neonatal intensive care unit (NICU) admission, neonatal respiratory distress syndrome (NRDS), ventilator support and a composite outcome combining major morbidities and neonatal death. Logistic regression models were performed to estimate the association between neonatal outcomes and BWD with different thresholds (≥15.0%, ≥20.0%, ≥25% and ≥ 30%). Generalized estimated equation (GEE) models were used to address intertwin correlation. Restrictive cubic spline (RCS) models were established to draw the dose-response relationship between BWD and the odds ratios of outcomes. Clustered receiver operating characteristic (ROC) curve analyses were performed to assess the predictive accuracy. RESULTS: Of 2348 twin pairs, including 1946 dichorionic twin pairs and 402 monochorionic twin pairs, BWD was significantly associated with NICU admission, regardless of the thresholds used. The incidence of NRDS, ventilator support and the composite outcome were significantly higher when a threshold of ≥20% or greater was chosen. The dose-response relationship showed nonlinear growth in the risk of adverse neonatal outcomes with increasing BWD. ROC analyses showed a low significant AUROC of 0.569 (95% CI: 0.526-0.612) for predicting NICU admission but no significant AUROCs for predicting other outcomes. A BWD of ≥30% provided a moderate increase in the likelihood of NICU admission [positive likelihood ratio (LR+) = 5.77]. CONCLUSION: Although BWD is independently associated with adverse neonatal outcomes, it is not a single predictor for neonatal outcomes given the weak discriminative ability to predict neonatal outcomes. A cutoff of 30% is more practical for risk stratification among twin gestations.

Association between gestational weight gain and perinatal outcomes among twin gestations based on the 2009 Institute of Medicine (IOM) guidelines: a systematic review.

BACKGROUND: Gestational weight gain (GWG) has been understudied among twin pregnancies. This systematic review aimed to review the data on the associations between GWG, based on the 2009 Institute of Medicine (IOM) guidelines and pregnancy outcomes among twin gestations. METHODS: A systematic review was performed according to the PRISMA guidelines. A search for eligible studies published from January 2010 to August 2020 was conducted in the EMBASE, PubMed, Web of Science, ScienceDirect, and Cochrane databases. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Data on study characteristics and main findings were extracted independently by two reviewers using a standard form. Outcomes of interest included (spontaneous) preterm birth (PTB), gestational hypertensive disorder (gestational hypertension and eclampsia), and small for gestational age (SGA). RESULTS: Eighteen observational studies of twin gestations met the inclusion criteria. GWG below the IOM recommendations was reported to be associated with increased PTB and SGA while GWG above the recommendation was associated with increased gestational hypertensive disorder. However, the results were inconsistent. Methodological limitations, such as a retrospective design, the use of weekly GWG, a small sample size and insufficient adjustment, impeded the clarification of the association between GWG and perinatal outcomes. In addition, the optimal GWG for underweight women was not fully studied. CONCLUSIONS: The maintenance of weight gain within the 2009 IOM guidelines would decrease the risks of adverse outcomes among twin pregnancies. However, rigorous studies are warranted to provide robust evidence to refine the optimal GWG among twin gestations.

Association of antenatal corticosteroids with morbidity and mortality among preterm multiple gestations: meta-analysis of observational studies.

OBJECTIVE: This meta-analysis aimed to assess the efficacy of antenatal corticosteroids (ACS) on morbidity and mortality among preterm multiple pregnancies. METHODS: The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies investigating the outcomes among preterm multiple gestations following to ACS, from their inception to 1 November 2020. Two authors independently performed the study selection, risk of bias assessment and data extraction. The primary outcomes were respiratory distress syndrome (RDS) and mortality and secondary outcomes included intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), necrotising enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Pooled ORs were obtained using random effects models. Subgroup analyses were performed to explain heterogeneity by ACS completeness, administration-to-delivery intervals (≤7 days) and single or multicentre. RESULTS: A total of 16 observational studies with 36 973 newborns were included in the meta-analysis. ACS treatment was associated with a reduction in RDS (OR 0.66; 95% CI 0.54 to 0.82; I2=91.4%; p<0.001), mortality (OR 0.64; 95% CI 0.50 to 0.81; I2=85.9%; p<0.001), IVH (OR 0.67; 95% CI 0.54 to 0.83; I2=77.4%; p<0.001) and PVL (OR 0.65; 95% CI 0.47 to 0.92; I2=75.5%; p<0.001). Subgroup analyses showed ACS completeness, administration-to-delivery interval and multicentre study affected these associations. DISCUSSION: ACS may be beneficial for reducing the risks of RDS, mortality, IVH and PVL among preterm multiple gestations. The efficacy of ACS could be affected by ACS completeness and administration-to-delivery. More robust evidence on the efficacy of ACS treatment among multiple gestations is warranted.

Should singleton birth weight standards be applied to identify small-for-gestational age twins?: analysis of a retrospective cohort study.

BACKGROUND: Twin birth weight percentiles are less popular in clinical management among twin pregnancies compared with singleton ones in China. This study aimed to compare the incidence and neonatal outcomes of small for gestational age (SGA) twins between the use of singleton and twin birth weight percentiles. METHODS: This was a retrospective cohort study of 3,027 pregnancies with liveborn twin pairs at gestational age of > 28 weeks. The newborns were categorized as SGA when a birthweight was less than the 10th percentile based on the singleton and twin references derived from Chinese population. Logistic regression models with generalized estimated equation (GEE) were utilized to evaluate the association between SGA twins and neonatal outcomes including neonatal unit admission, neonatal jaundice, neonatal respiratory distress (NRDS), neonatal asphyxia, ventilator support, hypoxic ischemic encephalopathy (HIE), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intracranial hemorrhage (ICH), culture-proven sepsis, neonatal death within 28 days after birth as well as the composite outcome. RESULTS: The incidence of SGA was 33.1 % based on the singleton reference and 7.3 % based on the twin reference. Both of SGA newborns defined by the singleton and twin references were associated with increases in neonatal unit admission, neonatal jaundice and ventilator support. In addition, SGA newborns defined by the twin reference were associated with increased rates of BPD (aOR, 2.61; 95 % CI: 1.18-5.78) as well as the severe composite outcome (aOR, 1.93; 95 % CI: 1.07-3.47). CONCLUSIONS: The use of singleton birth weight percentiles may result in misdiagnosed SGA newborns in twin gestations and the twin birth weight percentiles would be more useful to identify those who are at risk of adverse outcomes.

Ambient air pollution exposure associated with glucose homeostasis during pregnancy and gestational diabetes mellitus.

BACKGROUND: To investigate the effects of air pollution exposure during pregnancy on the indicators of glucose homeostasis and gestational diabetes mellitus (GDM). METHODS: We conducted a birth cohort study in Foshan, China during 2015-2019. Oral glucose tolerance test (OGTT) was administered to each participant during pregnancy. GDM was defined according to the International Association of Diabetes and Pregnancy Study Groups criteria (IADPSG). Air pollutant (fine particulate matter (PM2.5), particulate matter with an aerodynamic diameter of 10 µm or less (PM10), sulfate dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3)) concentrations from the air monitoring stations in Foshan were used to estimate individual air pollutant exposure during the first two trimesters. Linear and logistic regression models were employed to estimate the associations between air pollution exposure during the first two trimesters and OGTT glucose levels and GDM. RESULTS: Of 12,842 pregnant women, 3055 (23.8%) had GDM. A 10 µg/m3 increase in PM2.5, PM10 and SO2 during trimester 1, trimester 2 and two trimesters were associated with 0.07 mmol/L to 0.29 mmol/L increment in OGTT-fasting glucose levels in single-pollutant model. A 10 µg/m3 increase in NO2 and O3 during two trimesters were associated with 0.15 mmol/L and 0.12 mmol/L decrease in OGTT-fasting glucose in single-pollutant model. However, no significant or weaker effects of O3 during two trimesters on OGTT-fasting glucose were observed in two-pollutant models. Moreover, exposure to PM2.5, PM10 and SO2 were associated with increased risk of GDM in both single- and two-pollutant models. CONCLUSIONS: Our study suggests PM2.5, PM10 and SO2 exposure during the first two trimesters might increase the risk of GDM.

[Concentrations of PCDD/Fs in the atmosphere of Chongqing City and its seasonal variation].

As a comprehensive monitoring survey on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in Chongqing, 20 ambient air samples taken from 5 locations in four seasons were studied. The PCDD/F TEQ concentrations varied from 0.017 pg x m(-3) to 0.21 pg x m(-3). The average value was (0.094 +/- 0.054) pg x m(-3). The PCDD/F concentrations varied by locations and seasons, and the orders were: urban area > suburban area > background area, and Winter > Spring > Autumn > Summer. The concentrations of PCDD/Fs were 2.2-4.6 times higher in the winter than during the summer. The PCA results indicated that PCDD/F homologue pattern varied by seasons. The PCDD/F homologue pattern in particle dominated in winter and spring, and the pattern in gas dominated in summer and autumn. The mass concentration of PCDD/F congener was significantly positively correlated with that of SO2, NO2, PM10 and TSP, and insignificantly negatively correlated with that of O3, respectively. The results showed that spatial distribution and seasonal variation of atmospheric PCDD/Fs in Chongqing was consistent with that of these conventional indicators, and the PCDD/Fs pollution was closely related with the emission sources of SO2, NO2, PM10 and TSP.

Chemical constituents from the roots of Periploca sepium with insecticidal activity.

Five compounds were isolated from the root powder of Periploca sepium. By mainly HR-ESI-MS, (1)H, (13)C, and 2D NMR spectral data, they were characterized as periplocoside X (1), oligasaccharide A (2), periplocoside A (3), periplocoside E (4), and periplocoside N (5), respectively. Compounds 1-5 were found to possess insecticidal activities against the red imported fire ant. Among the compounds, periplocoside X showed significant activity with LD(50) values of 748.99, 116.62, 2169.58, and 3079.33mg/l against soldiers, workers, males, and alate females of red imported fire ant, respectively.

Molecular structure, expression analysis and functional characterization of APRIL (TNFSF 13) in goat (Capra hircus).

A proliferation-inducing ligand (APRIL) is an important member of the tumor necrosis factor (TNF) superfamily. In the present study, a novel cDNA was isolated from the spleen of goat by RT-PCR and designated as goat APRIL (gAPRIL). The open reading frame (ORF) of this cDNA covered 753bp, encoding a protein of 250 amino acids. Sequence comparison showed that gAPRIL contains a predicted transmembrane domain, a putative furin protease cleavage site, and two cysteine residues, which are the typical characteristics of TNF gene in mammals. The predicted three dimensional (3D) structure of soluble part of the gAPRIL (gsAPRIL) monomer analyzed by comparative protein modeling revealed that it is very similar to its counterparts. Real-time PCR analysis revealed that gAPRIL was constitutively expressed in various tissues. Recombinant gsAPRIL fused with NusA tag was efficiently produced in Escherichia coli BL21 (DE3) and then analyzed by the SDS-PAGE as well as western blot. Laser scanning confocal microscopy analysis showed gsAPRIL could bind to its receptors. In vitro, the MTT and flow cytometric methods revealed that purified gsAPRIL protein was not only able to promote survival/proliferation of goat splenocytes, but also able to stimulate survival/proliferation of mouse B cells. These results indicated that gAPRIL plays an important role in survival/proliferation of goat splenocytes and provided a basis for investigating its potential to be used as an immunoadjuvant for enhancing vaccine efficacy and as an immunotherapeutic in goats.

[Determination of phthalate esters in sediment by accelerated solvent extraction and gas chromatography-triple quadrupole mass spectrometry].

A method for the determination of seventeen phthalate esters in sediment by accelerated solvent extraction (ASE), gel-permeation chromatography (GPC) and gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) has been developed. The target compounds were extracted at 100 degrees C and 103.4 MPa (1500 psi) by ASE using the mixtures of dichloromethane and acetone (1:1, v/v) as solvent. In order to eliminate the interferences from larger molecular sizes, the extract was purified at a flow rate of 5.0 mL/min by GPC. Following that, the extract was concentrated to a final volume of 1 mL exactly. The GC-MS/MS was applied to quantitative and qualitative analysis. Internal standard calibration approach was adopted, and the detection limits of seventeen phthalate esters ranging from 0.05 to 0.40 microg/kg were obtained. The correlation coefficients were beyond 0.996, the recoveries were from 50.5% to 107.9%, and the relative standard deviations were from 3.5% to 13.9%. Besides, the surrogate compounds spiked were used to monitor the performance of the method, and the recoveries were from 65.3% to 95.8% for the three surrogate compounds. The method is fast, sensitive and exact for analyzing seventeen phthalate esters simultaneously.

Investigation on metal pollution in the sediment of Chongqing segment of Yangtse River.

Basing on experiment dada collected from 1995 to 2007 at Chongqing segment of Yangtse River, the pollution and the potential toxic effect of sediment were depicted and characterized by using the Index of Geoaccumulation (I(geo)) method and the Logistic Regression model respectively. Results showed that the sediment had been slightly polluted by metals and had possible adverse effect on aquatic life. According to the I(geo), the order of the analyzed metals, arranging from highest to lowest pollution degree, was Cd > Hg > Pb > Cu > Zn > As. Meanwhile, sediment contamination level had been obviously decreasing before the storing water of Three Gorge Reservoir.

Molecular cloning, functional characterization and phylogenetic analysis of B-cell activating factor in zebrafish (Danio rerio).

B-cell activating factor (BAFF), belonging to the TNF family, is a critical cytokine for B-cell survival, proliferation, maturation and differentiation. In the present study we cloned the cDNA of zebrafish (Danio rerio) BAFF (designated zBAFF) by reverse transcription-PCR (RT-PCR). The open reading frame (ORF) of zBAFF consists of 807 bases encoding a protein of 268 amino acids. The deduced amino acid sequence of its cDNA possessed the TNF family signature, a transmembrane domain, and three cysteine residues, which are the typical characteristics of TNF gene in mammals and birds. Phylogenetic analysis exhibits the highest identity score 67.6, 61.4 and 66.9% with the rainbow trout, tetraodon and salmon counterparts, respectively. The identity to avian and mammalian BAFFs ranges from 49.7 to 53.8%. Recombinant soluble zBAFF (zsBAFF) was fused with a small ubiquitin-related modifier gene (SUMO) to enhance the soluble expression level in Escherichia coli BL21 (DE3). The resulting fused protein SUMO-zsBAFF was highly expressed in BL21 (DE3) with a molecular weight of 38 kDa. The fusing protein was purified using metal chellate affinity chromatography (Ni-NTA) and cleaved by a SUMO-specific protease, then confirmed by SDS-PAGE and Western blotting analysis. In vitro, the MTT assay indicated that the purified zsBAFF as well as SUMO-zsBAFF proteins were able to promote spleen lymphocyte survival in a dose-dependent manner also to co-stimulate the proliferation of mammalian B-cells with anti-IgM. Thus, the fusion protein represents a readily obtainable source of biologically active zsBAFF that may prove useful in further studies on zebrafish BAFF and its receptors.

Bioaccumulative characteristics of hexabromocyclododecanes in freshwater species from an electronic waste recycling area in China.

Hexabromocyclododecanes (HBCDs) are now emerging ubiquitous contaminants due to their wide usage, persistence and toxicities. To investigate the bioaccumulative characteristics of HBCDs, sediments, Winkle (Littorina littorea), crucian carp (Carassius carassius) and loach (Misgurnus anguillicaudatus) were collected from two streams near an E-waste dismantling site in China, and HBCD exposure test was then conducted on Chinese rare minnow. The concentration of HBCDs was 14 ng g(-1) dry weight in sediments, 186, 377 and 1791 ng g(-1) lipid weight in winkle, crucian carp and loach, respectively. gamma-HBCD was found to be the dominant diastereoisomer in the sediments (63% of total HBCDs). However, alpha-HBCD was selectively accumulated in the biotic samples and contributed to 77%, 63% and 63% of total HBCDs in winkle, crucian carp and loach, respectively. Moreover, an enrichment of (-)-enantiomers of alpha- and gamma-HBCD were found in the winkle. The reverse results were observed in the crucian carp and loach. Similar observations of diastereoisomeric and enantiomeric composition were obtained in Chinese rare minnow with those found in the crucian carp and loach. These results indicate that the freshwater species from the streams are contaminated by HBCDs. alpha-HBCD can be selectively accumulated in organisms and the accumulative characteristics are enantioselective among species.

Biomonitoring of detoxifying activity as measured by CYP1A1 induction in Yangtze and Jialing Rivers in Chongqing City in China.

In order to determine the potential toxicities of organic pollutants in the river water of Chongqing City (China), chemicals were extracted from surface water of the Yangtze River and Jialing River between August 2004 and January 2005. Gas chromatography/mass spectrometry (GC/MS) analysis showed that the main compounds detected were polycyclic aromatic hydrocarbons (PAH) and phthalate acid esters (PAE). The ethoxyresorufin O-deethylase (EROD) test showed that the toxic equivalency (TEQ) values of the samples ranged from 0.9 to 13.3 x 10(-4) pg 2,3,7,8-TCDD/L river water. Incubation of H4IIE cells with organic extracts produced a time-dependent induction of cytochrome P-450 1A1 (CYP1A1) mRNA expression as determined by (1) reverse-transcription polymerase chain reaction (RT-PCR), (2) positive binding to aryl hydrocarbon receptor (AhR), and (3) activation of xenobiotic response element (XRE) by electrophoretic mobility shift assay (EMSA). Data indicated that organic extracts from the river water of Chongqing City induced CYP1A1 activity in hepatocytes in vitro. A possible mechanism underlying toxicity might involve the AhR signal pathway, but further studies are necessary.