UPLC-QTOF mass spectrometry detection of four endocrine disrupting chemicals (Methyl Paraben, 2,4-Dichlorophenoxyacetic acid, Monobutyl Phthalate, and Bisphenol A) in urine of Filipino women

Background and Objective@#Endocrine Disrupting Chemicals (EDCs) are ubiquitously found as low-level contaminants and pose serious threat to women’s health. EDCs may result in various reproductive disorders, fetal birth and developmental abnormalities, and endocrine and metabolic disorders. EDCs can be detected in body fluids of exposed individuals including blood and urine. This study aimed to detect four EDCs — Methyl Paraben (MP), 2,4-Dichlorophenoxyacetic acid (2,4-D), Monobutyl Phthalate (MBP), and Bisphenol A (BPA) in urine samples of women using Ultra-Performance Liquid Chromatography – Quadrupole Time-of-Flight (UPLC-QTOF) mass spectrometry.@*Methods@#Sequential steps of enzymatic deconjugation, liquid-liquid extraction, solid phase extraction, and liquid chromatography separation and mass spectrometry detection were optimized in urine samples. The method was used to analyze 70 urine samples from women of reproductive age.@*Results@#The sample preparation method showed a recovery ranging from 86.6% (MBP) to 100 % (2,4-D). The method demonstrated limits of quantitation ranging from 1.52 ng/m(MP) to 6.46 ng/mL(2,4D). Intra-day precisions expressed as relative standard deviation were all below 15% while accuracy was shown to range from 67.10% (2,4-D) to 102.39% (MBP). MP was detected in nine samples (12.86%) with a geometric mean value of 10.15 ng/ml (range: 3.62-52.39 ng/ml). MBP was detected in 68 samples (97.14%) with a geometric mean value of 97.62 ng/ml (range: 15.32-698.18 ng/ml). BPA was detected only once (9.58 ng/ml) while 2, 4-D was not detected in all samples.@*Conclusion@#A UPLC-QTOF mass spectrometry method to detect four EDCs at parts per billion level (ng/ml) was adapted and applied for analysis of urine samples. This method can find applicability in routine testing of clinical specimens as well as surveillance and other epidemiological studies.

Association between serum bisphenol A concentration and incident risk of hypertension / 环境与职业医学

Background Previous studies have shown that bisphenol A exposure is associated with the risk of hypertension; however, most of them are cross-sectional and the conclusions are not consistent. Objective To evaluate the association between bisphenol A exposure and the incident risk of hypertension. Methods Based on a nested case-control design involving 1990 subjects derived from the Dongfeng-Tongji cohort, a total of 1080 subjects were included in this study after excluding 887 hypertensive cases at baseline and 23 subjects with missing blood pressure data in follow-up visits. Epidemiological information was collected through questionnaire survey, and serum bisphenol A concentration was detected by high performance liquid chromatography tandem mass spectrometry. Logistic regression model was used to analyze the potential association between serum bisphenol A level and the risk of hypertension incidence, and linear regression model was used to analyze the association between serum bisphenol A level and blood pressure changes between baseline and follow-up. Results The average age of the 1 080 participants was (62.03±7.45) years, of which 41.1% were male. During the follow-up period, a total of 477 (44.2%) developed hypertension. The median serum concentration of bisphenol A in the total population was 3.15 μg·L−1, and the baseline bisphenol A concentration in the new case group (3.24 μg·L−1) was higher than that in the control group (2.98 μg·L−1) (P<0.05). After adjustment for selected covariates, the risk of hypertension increased by 12% (OR=1.12, 95%CI: 1.02, 1.22) for each unit increase in naturally log-transformed bisphenol A; the systolic blood pressure and diastolic blood pressure increased by 1.88 (95%CI: 1.08, 2.69) mmHg and 1.14 (95%CI: 0.68, 1.61) mmHg, respectively. Compared with the low bisphenol A tertile group, the risk of hypertension in the middle tertile and high tertile groups increased by 39% (OR=1.39, 95%CI: 1.01, 1.91) and 40% (OR=1.40, 95%CI: 1.02, 1.93) respectively; the systolic blood pressure increased by 5.91 (95%CI: 3.06, 8.76) mmHg and 5.71 (95%CI: 2.82, 8.59) mmHg, and the diastolic blood pressure increased by 3.09 (95%CI: 3.06, 8.59) mmHg and 2.89 (95%CI: 1.22, 4.57) mmHg, respectively (Ptrend<0.001). A positive association between serum bisphenol A level and hypertension was found among those who were female, never/former smokers, never/former drinkers, without family history of hypertension, with physical exercise, and with prehypertension at baseline (Ptrend<0.05). There was no interaction between selected stratified variables and bisphenol A levels on hypertension (Pinteraction>0.05). Conclusion Bisphenol A exposure is positively associated with the risk of hypertension.

Effects of Bisphenol A and Its Substitute, Bisphenol F, on the Gut Microbiota in Mice / 生物医学与环境科学（英文）

OBJECTIVE@#The aim of this study was to assess the impact of bisphenol A (BPA) and its substitute, bisphenol F (BPF), on the colonic fecal community structure and function of mice.@*METHODS@#We exposed 6-8-week-old male C57BL/6 mice to 5 mg/(kg∙day) and 50 μg/(kg∙day) of BPA or BPF for 14 days. Fecal samples from the colon were analyzed using 16S rRNA sequencing.@*RESULTS@#Gut microbiome community richness and diversity, species composition, and function were significantly altered in mice exposed to BPA or BPF. This change was characterized by elevated levels of Ruminococcaceae UCG-010 and Oscillibacter and decreased levels of Prevotella 9 and Streptococcus. Additionally, pathways related to carbohydrate and amino acid metabolism showed substantial enrichment.@*CONCLUSION@#Mice exposed to different BP analogs exhibited distinct gut bacterial community richness, composition, and related metabolic pathways. Considering the essential role of gut bacteria in maintaining intestinal homeostasis, our study highlights the intestinal toxicity of BPs in vertebrates.

Rutin forestalls dysregulated cardiac bioenergetics in bisphenol A and dibutyl phthalate-exposed rats through PPAR? and AMPK modulation

Objectives: Proper cardiac function is greatly dependent on adequate supply and metabolism of energy substrates. Environmental pollutants exposure including plasticizers can trigger adverse cardiac metabolic events. This study was designed to investigate the ameliorative effect of rutin (Rt) on dysregulated cardiac energy metabolism in plasticizer-exposed rats. Materials and Methods: Forty-two rats were randomised into seven groups (n = 6): Control (0.1% dimethyl sulfoxide), bisphenol A (BPA, 25 mg/kg, p.o), dibutyl phthalate (DBP, 25 mg/kg, p.o), BPA + Rt 25 mg/kg, Rt 50 mg/kg, DBP + Rt (25 mg/kg, Rt 50 mg/kg), BPA + DBP and BPA + DBP + Rt, daily for 21 days. Results: BPA and DBP exposure increased plasma glucose, reduced insulin, and increased plasma and cardiac free fatty-acid. Cardiac glucose-6-phosphate level, hexokinase and pyruvate dehydrogenase activities increased in DBP while BPA reduced these variables. Cardiac glucose transporter-4 expression was reduced in BPA group, while cardiac peroxisome proliferator-activated receptor-alpha (PPAR?) and AMP-activated protein kinase (AMPK) expression increased in BPA and DBP-treated rats. However, Rt administration prevents impaired cardiac bioenergetics and glucometabolic regulation. Conclusion: Summarily, Rt improves BPA and DBP-impaired cardiac bioenergetics through PPAR? and AMPK modulation.

Does bisphenol A (BPA) participates in the pathogenesis of Polycystic Ovary Syndrome (PCOS)?

Abstract PCOS is an endocrine disorder characterized by chronic anovulation, hyperandrogenism, and polycystic ovaries. Its etiology is uncertain. It is debated whether BPA would be a component of the environmental factor in the etiology of PCOS. Contamination by BPA can occur from food packaging (exposure during the diet) and through skin absorption and/or inhalation. It can be transferred to the fetus via the placenta or to the infant via breast milk, and it can be found in follicular fluid, fetal serum, and amniotic fluid. The phenolic structure of BPA allows it to interact with Estrogen Receptors (ERs) through genomic signaling, in which BPA binds to nuclear ERα or Erβ, or through nongenomic signaling by binding to membrane ERs, prompting a rapid and intense response. With daily and constant exposure, BPA's tendency to bioaccumulate and its ability to activate nongenomic signaling pathways can alter women's metabolic and reproductive function, leading to hyperandrogenism, insulin resistance, obesity, atherogenic dyslipidemia, chronic inflammatory state, and anovulation and favoring PCOS. The harmful changes caused by BPA can be passed on to future generations without the need for additional exposure because of epigenetic modifications. Not only high BPA levels can produce harmful effects, but at low levels, BPA may be harmful when exposure occurs during the most vulnerable periods, such as the fetal and neonatal periods, as well as during the prepubertal age causing an early accumulation of BPA in the body. Learning how BPA participates in the pathogenesis of PCOS poses a challenge and further studies should be conducted.

Effects of bisphenol A and its three analogs on triglyceride synthesis in hepatocytes / 中国医科大学学报

Objective To investigate whether BPA and its substitutes BPAF,BPB,and BPS can induce lipid accumulation in hepato-cytes.Methods HL-7702 cells were treated with BPA,BPAF,BPB,or BPS for 24 h.Lipid droplet accumulation in cells was observed via oil red O staining,and triglyceride content was determined through the GPO-PAP chemical-enzymatic method.In addition,qRT-PCR was used to detect the expression of triglyceride synthesis-related genes.Results Red lipid droplets of different sizes could be observed in the BPA,BPAF,BPB,and BPS groups.The intracellular triglyceride content increased significantly under 1 and 50 μmol/L BPA,10 and 50μmol/L BPAF,1,10,and 50μmol/L BPB,and 50μmol/L BPS.LIPIN2 mRNA expression level increased significantly under 10μmol/L BPAF,10μmol/L BPB,and 1 and 10μmol/L BPS.DGAT2 mRNA expression increased significantly under 50μmol/L BPA,10μmol/L BPAF,10 and 50μmol/L BPB,and 1μmol/L BPS.Conclusion BPAF,BPB,and BPS can increase intracellular triglyceride synthesis by upregulating LIPIN2 and DGAT2 mRNA expression,leading to intracellular fat accumulation and increased triglyceride con-tent in HL-7702 cells.

Research progress in detection method for bisphenol A in food packaging materials / 上海预防医学

As an industrial chemical， bisphenol A is widely used in various food packaging materials. However， it is an endocrine disrupting chemical， which has estrogen activity and can cause certain damage to humans. So far， there are few studies on the detection of bisphenol A in self-heating food packaging materials， and there remains a lack of relevant standard. Therefore， it is necessary to establish a simple， sensitive and efficient method for the detection of bisphenol A in self-heating food. This study briefly introduces the pretreatment methods of bisphenol A， such as ultrasonic extraction， solid phase extraction， accelerated solvent extraction， and detection methods， such as gas chromatography-mass spectrometry， high performance liquid chromatography， fluorescent detection， and electrochemical detection.

Advances in the effects of exposure to bisphenol A and its analogues during pregnancy on maternal and infant health / 国际儿科学杂志

Bisphenol A(BPA)as a typical environmental endocrine disruptor, has been widely used in daily consumer goods.It has reproductive, developmental, neurotoxicity and other biological toxicity, so it is gradually replaced by bisphenol F, bisphenol S, bisphenol AF and other analogues.Studies have shown that BPA and its analogues can enter the human body through many ways, have been detected in human blood, urine, placenta, breast milk, amniotic fluid and other tissue samples, and transmitted to the fetus, causing a variety of toxic effects, thus affecting the health of pregnant women and fetuses, and may lead to adverse pregnancy outcomes such as preterm delivery, abortion, low birth weight and so on.This article reviews the ways and current situation of exposure to BPA and its analogues during pregnancy in recent years, and its effects on maternal and fetal health, and puts forward reasonable suggestions for maternal and infant health from the point of view of exposure to adverse environmental factors, so as to provide inspiration for future research.

Mechanism of nephrotoxicity induced by chronic exposure of bisphenol A in mice based on oxidative stress and cell apoptosis / 生物工程学报

Bisphenol A (BPA) is widely used to produce epoxy resin and polycarbonate plastic products. In severe cases, these plastics may release BPA, which then infiltrates into the environment. Various concentrations of BPA have been found in most biological fluid. Its presence has been well shown to be closely related to many chronic diseases, including chronic kidney disease (CKD). However, little is known regarding the adverse effects of BPA exposure and its succedent cellular events on CKD. Hence, in the current in vivo study, we aimed to assess the effects of chronic exposure to BPA on animal nephrotoxicity through investigating oxidative stress and apoptosis. Upon exposure to BPA at 0.01, 0.1, and 1 mg/L via drinking water for four weeks, the mated and pregnant females were continuously exposed to BPA until weaning. Subsequently, three weeks old F1-male neonates were also orally challenged with the same three doses of BPA for ten weeks. The results showed that the kidneys of 0.1 and 1 mg/L BPA-treated mice were seriously damaged; the contents of serum renal function indexes and lipid peroxidation products were significantly increased, including urea nitrogen, creatinine, uric acid, and thiobarbituric acid reactive substances; the morphological structure of mouse kidneys was impaired; the expressions of antioxidant-related genes at mRNA and protein levels from mouse kidneys were markedly diminished, including glutathione-S-transferase, superoxide dismutase, and catalase; the expressions of genes and proteins related to apoptosis index (ratio of Bax/Bcl-1 and Caspase-3) were significantly enhanced. The data manifested that cumulative oxidative stress and apoptosis might play an essential role in the animal nephrotoxicity induced by chronic exposure to BPA.

Bisphenol A induces testicular oxidative stress in mice leading to ferroptosis / 亚洲男科学杂志(英文版)

Bisphenol A is a common environmental factor and endocrine disruptor that exerts a negative impact on male reproductive ability. By exploring bisphenol A-induced testicular cell death using the Institute of Cancer Research (ICR) mouse model, we found that a ferroptosis phenomenon may exist. Mice were divided into six groups and administered different doses of bisphenol A via intragastric gavage once daily for 45 consecutive days. Serum was then collected to determine the levels of superoxide dismutase and malondialdehyde. Epididymal sperm was also collected for semen analysis, and testicular tissue was collected for ferritin content determination, electron microscope observation of mitochondrial morphology, immunohistochemistry, real-time quantitative polymerase chain reaction, and western blot analysis. Exposure to bisphenol A was found to decrease sperm quality and cause oxidative damage, iron accumulation, and mitochondrial damage in the testes of mice. In addition, bisphenol A was confirmed to affect the expression of the ferroptosis-related genes, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), cyclooxygenase 2 (COX2), and acyl-CoA synthetase 4 (ACSL4) in mouse testicular tissues. Accordingly, we speculate that bisphenol A induces oxidative stress, which leads to the ferroptosis of testicular cells. Overall, the inhibition of ferroptosis may be a potential strategy to reduce male reproductive toxicity caused by bisphenol A.

Principales disruptores endocrinos vinculados con salud reproductiva femenina: bases biológicas de su asociación / Main endocrine disruptors related to female reproductive health: biological basis of their association

Resumen Se denominan disruptores endocrinos (DEs) a aquellas sustancias químicas capaces de interferir con la homeostasis hormonal, alterando la síntesis, función, almacenamiento y/o metabolismo de las hormonas. Estas sustancias se encuentran en el ambiente y en una amplia variedad de productos de uso diario, por lo que la exposición humana es permanente. Experimentos con animales han confirmado la capacidad de los DEs para inducir desórdenes reproductivos, por lo que se ha sugerido que podrían ser un factor importante como causa de subfertilidad humana. El bisfenol A, los ftalatos y los compuestos orgánicos persistentes son tres tipos de DEs presentes en el medio ambiente y asociados con alteraciones reproductivas. Consultando las bases de datos MEDLINE y PubMed, en la presente revisión, se reúne bibliografía de los últimos 20 años donde se evalúan los efectos provocados por la exposición a los DEs mencionados en mujeres durante la vida adulta. Se resumen los efectos sobre marcadores de reserva ovárica y los resultados de tratamientos de fertilización in vitro. Por otro lado, se evalúa la evidencia a nivel molecular de los efectos provocados por los DEs sobre la fisiología reproductiva en estudios in vitro e in vivo.

Abstract Endocrine disruptors (EDs) are those chemical substances capable of interfering with hormonal homeostasis, altering the synthesis, function, storage and / or metabolism of hormones. These substances are found in the environment and in a wide variety of products for daily use, so human exposure is permanent. Animal experiments have confirmed the capacity of EDs to induce reproductive disorders, which is why it has been suggested that they could be an important factor in causing human subfertility. Bisphenol A, phthalates and persistent organic compounds are three types of EDs present in the environment and associated with reproductive disorders. Consulting the MEDLINE and PubMed databases, in this review, a bibliography of the last 20 years is gathered where the effects caused by exposure to the mentioned EDs in women during adult life are evaluated. The effects on ovarian reserve markers and the results of in vitro fertilization treatments are summarized. On the other hand, the evidence at the molecular level of the effects caused by EDs on reproductive physiology is evaluated in in vitro and in vivo studies.

A Study on the Parenting Styles and Parental Stress of Parents of (Attention Deficit Hyperactivity Disorder) ADHD Children

Background: There are several steps involved in deciding if a child has ADHD. No single test is available to diagnose ADHD and many other problems such as depression, anxiety, sleep problems and certain types of learning disabilities can also have similar symptoms. One of the process involves doing a medical examination, including hearing and vision tests, to rule out other problems with symptoms like ADHD. Diagnosis of ADHD includes a checklist for rating ADHD symptoms and taking a history of the child from parents, teachers, and sometimes, the child itself. Aim & Objectives: To know the prevalence of psychiatric co-morbidities in ADHD and to assess parental stress and parenting style among parents of children having ADHD.Material & Methods:A total of 78 children (6 to 18 years of age) and their parents were selected for the completion this study. The study was carried out in the Department of Psychiatry, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi. Bivariate table and chi-square/Fisher Exact test were used. Correlation test has also been applied to know the association between demographic variables and their responses. Conclusions:We conclude that specific scales of the CBCL may help to identify specific comorbidities within ADHD cases in the primary care setting.

Research progress on reproductive toxicity and reproductive system tumors induced by environmental endocrine disrupting chemicals / 环境与职业医学

Environmental endocrine disrupting chemicals are a kind of exogenous chemicals that generally exist in the environment, and can disturb the endocrine homeostasis and adversely affect reproductive, immune, neurological, and other functions after entering the body, among which the damage to the reproductive system is the most significant one. Studies have confirmed that the long-term exposure to environmental endocrine disrupting chemicals have irreversible and harmful effects on primordial germ cell growth, reproductive organ development, and reproductive endocrine regulation, and also have obvious correlations with the occurrence and development of various reproductive system tumors. This paper reviewed various reproductive toxicities induced by common environmental endocrine disrupting chemicals in the developmental and reproductive stages, and associated mechanisms involved in the occurrence and development of reproductive system tumors.

Effects of bisphenol A exposure at different circadian time on hepatic lipid metabolism in mice / 环境与职业医学

Background Lipid metabolism in liver shows circadian-dependent profiles. The hepatotoxicity of environmental chemicals is dependent on circadian time. Objective To observe the effects of bisphenol A (BPA) exposure at different zeitgeber time (ZT) on hepatic and blood lipid metabolism and decipher the underlying mechanisms related to circadian rhythm in mice. Methods Thirty-five female C57BL/6J mice were sacrificed every 4 h in a light-dark cycle (12 h/12 h). The liver tissues were collected to describe the circadian profiles of hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels within 24 h. Thirty female mice were divided into 6 groups by the timing (ZT3 represents the 3 h after light on, ZT15 represents the 3 h after light off) and dose (50 or 500 μg·kg−1·d−1) of BPA exposure to observe hepatotoxicity. Mice were gavaged with designed doses of BPA once per day for 4 weeks. Mice were maintained with ad libitum access to food and water and measured body weight weekly. After the experiment, mice were euthanatized and liver tissues were separated to determine the biochemical indicators of lipid metabolism and lipid metabolism- and circadian-related gene mRNA expressions. Results Hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels were rhythmic during a 24 h period in mice. At ZT3 and ZT15, BPA did not alter body weight, plasma glucose, plasma total cholesterol, plasma low density lipoprotein cholesterol, and plasma triglycerides (P>0.05). The plasma high density lipoprotein cholesterol decreased in the 50 μg·kg−1·d−1 BPA group at ZT3 by 14.56% compared with the control group (P<0.05). The liver triglycerides increased in the 50 μg·kg−1·d−1 BPA group at ZT15 by 115.20% compared with the control group (P<0.05). BPA decreased Srebp1c mRNA expression level when dosing at ZT3 and increased Chrebp, Srebp1c, and Acc1 mRNA expression levels when dosing at ZT15 compared with the control group (P<0.05). BPA increased Bmal1 mRNA expression level and decreased Rev-erbα mRNA expression level at ZT3 exposure and decreased Bmal1 and increased Rev-erbα mRNA expression level at ZT15 exposure (P<0.05). Conclusion BPA exposure at light or dark period has different effects on hepatic lipid metabolism in mice. Hepatic lipid deposit appears when BPA is dosed at dark period. Rev-erbα-Bmal1 regulation circuits and the subsequent upregulation of Srebp1c and Chrebp and the target gene Acc1 may be involved.

Release of leachable products from resinous compounds in the saliva of children with anterior open bite treated with spur

Abstract To evaluate the release of bisphenol-A glycidyl methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), bisphenol A (BPA), and phthalates of the composite resin used in the bonding of spurs applied in the treatment of children with anterior open bite and its effects on human keratinocytes. Methodology Saliva samples of 22 children were collected before spur attachment (baseline) and 30 minutes (min) and 24 hours (h) after spur bonding. Analysis was performed using high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (HPLC-MS/MS) and gas chromatography coupled to mass spectrometry (GC-MS). Standardized resin increments were added to three different dilutions of the cell culture medium. Keratinocytes (HaCaT) were cultivated in the conditioned media and evaluated for cell viability (MTT) and cell scratch assay. Results The levels of BisGMA (1.74±0.27 μg/mL), TEGDMA (2.29±0.36 μg/mL), and BPA (3.264±0.88 μg/L) in the saliva after 30 min, in comparison to baseline (0±0 μg/mL, 0±0 μg/mL, and 1.15±0.21 μg/L, respectively), presented higher numbers. After 24 h, the levels of the monomers were similar to the baseline. Phthalates showed no significant difference among groups. HaCat cells showed increased viability and reduced cell migration over time after exposure to methacrylate-based resin composites. Conclusion Resin composites, used to attach spurs in children with anterior open bite during orthodontic treatment, release monomers after polymerization and can influence the behavior of human keratinocytes, even at very low concentrations. Orthodontists should be aware of the risks of the resinous compounds release and preventive procedures should be held to reduce patient exposure.

Associations between urinary bisphenol A concentrations during pregnancy and gestational age / 上海预防医学

Objective We aimed to assess the association between urinary bisphenol A(BPA)concentrations and gestational age in pregnant women. Methods A total of 248 pregnant women were recruited from a maternal and child care hospital in Shanghai. A questionnaire survey was completed to collect socio-demographic information and spot urine samples were collected during pregnancy. Gas chromatography-tandem mass spectrometry(GC-MS/MS)was used to measure BPA concentrations in urine samples. Linear relationship between urinary BPA level and gestational age was assessed by using generalized additive models. Multivariate regression model was used to evaluate associations of prenatal BPA exposure with gestational age. Results BPA was detected in all the urine samples. Median value and geometric mean of urinary BPA levels were 0.85 μg/L and 1.21 μg/L, respectively. Linear relationship between urinary BPA concentration and gestational weeks was confirmed(non-linear P > 0.05). Positive association between urinary BPA level and gestational age was indicated(regression coefficient, β = 0.19;95%CI:0.04-0.35;P = 0.016). However, it was only observed in girls, stratified by sex of newborns(β = 0.18;95%CI:0.03-0.34;P = 0.020). After stratification by trimester, no significant association was found in the second or the third trimesters. Conclusion Pregnant women are extensively exposed to BPA. Urinary BPA exposure during pregnancy may extend gestational age, especially in girls.

Determination of bisphenol A in water by truncated aptamer-fluorescence method / 预防医学

Objective@#To establish a fluorescence method based on turncated aptamer for the determination of bisphenol A in water.@*Methods@#The bisphenol A truncated aptamer containing 38 bases was selected as a recognition module, and was modified with the fluorophore 6-FAM at the 5'end. The 3'end of the complementary sequence cDNA was modified with the quencher DABCYL. The standard solutions of bisphenol A and interfering compounds were configured. The detection system was established after optimizing the number of bases in cDNA, the concentration ratio of truncated aptamer to cDNA, the incubation temperature and time, and the pH of the buffer. The specificity and recovery experiments were carried out. @*Results@#When the complementary sequence cDNA included 9 bases, the concentration ratio of the truncated aptamer to cDNA was 1:1.5, the pH value of the buffer solution was 7.5, the cDNA was incubated at 55 ℃ for 60 minutes, in the concentration range of 10-75 pmol/L, the linear regression equation was y=2 230.7x+110 825, the correlation coefficient was 0.926. The limits of detection was 3.3 pmol/L. The difference values of fluorescence intensity between tetrabromobisphenol A, estradiol, estriol, bisphenol S and bisphenol A were obviously different, so there was no significant interference to the test result. The recovery rates were 97.8%, 98.8% and 102.3% with the spiked concentrations of 20.0, 40.0 and 60.0 pmol/L. The relative standard deviations were 4.4%, 2.1% and 2.6% (n=5), respectively. @*Conclusion@#The fluorescence method based on turncated aptamer has the advantages of easy operation, high sensitivity and specificity, which can be used for the determination of bisphenol A in water.

Effects of bisphenol A on apoptosis of ovarian preantral follicular granulosa cells and ovarian development in mice / 南方医科大学学报

OBJECTIVE@#To investigate the effect of environmental estrogen bisphenol A (BPA) exposure on apoptosis of mouse ovarian preantral follicular granulosa cells and ovarian development and explore the underlying mechanism.@*METHODS@#Mouse ovarian preantral follicular granulosa cells were isolated from female ICR mice at postnatal day (PND) 10 and cultured @*RESULTS@#Compared with the control cells group, the isolated cells exposed to a low concentration of BPA (50 μmol/L) showed a significantly lowered apoptosis rate, increased mitochondrial membrane potential, and enhanced cellular proliferation (@*CONCLUSIONS@#BPA can concentration-dependently regulate the function of ovarian preantral follicular granulosa cells in mice and potentially affects both the pregnant mice and the offspring female mice in light of early ovarian development.

The association between urinary bisphenol A levels and nonalcoholic fatty liver disease in Korean adults: Korean National Environmental Health Survey (KoNEHS) 2015-2017

BACKGROUND@#Nonalcoholic fatty liver disease (NAFLD) is becoming a global health problem. Bisphenol A (BPA), one of most widely used environmental chemicals, is suspected to be a contributor to the development NAFLD. This study was performed to examine the relationship between human BPA levels and risk of NAFLD.@*METHODS@#The data (n = 3476 adults: 1474 men and 2002 women) used in this study were obtained from the Korean National Environmental Health Survey III (2015-2017). BPA levels were measured in urine samples. NAFLD was defined using hepatic steatosis index after exclusion of other causes of hepatic diseases.@*RESULTS@#There was a significant linear relationship between the elevated urinary BPA concentrations and risk of NAFLD. In a univariate analysis, odds ratio (OR) of the highest quartile of urinary BPA level was 1.47 [95% confidence interval (CI) 1.11-1.94] compared to the lowest quartile. After adjusted with covariates, the ORs for NAFLD in the third and fourth quartiles were 1.31 [95% CI 1.03-1.67] and 1.32 [95% CI 1.03-1.70], respectively.@*CONCLUSIONS@#Urinary BPA levels are positively associated with the risk of NAFLD in adults. Further experimental studies are needed to understand the molecular mechanisms of BPA on NAFLD prevalence.

The effects of photoperiodism and exposure to bisphenol A on hepatic lipid metabolism in female mice / 中国职业医学

OBJECTIVE: To analyze the effects and the underlying mechanisms of photoperiodism and exposure to bisphenol A(BPA) on hepatic lipid metabolism in female mice. METHODS: A 2×2 factorial design was used. The photoperiod factor was set to fixed and shifted photoperiod, and the BPA factor was set to BPA exposure(BPA group) and non-exposure(control group). Specific pathogen free female C57 BL/6 J mice were randomly divided into four groups: fixed photoperiod control group, shifted photoperiod control group, fixed photoperiod BPA group, and shifted photoperiod BPA group, with eight rats in each group. The fixed photoperiod mice received a 12 ∶12 hours light-dark cycle, and the shifted photoperiod mice experienced reversed light-dark cycle once a week. Mice in BPA group were administered a dose of BPA 50 μg/kg body weigh by gavage, while mice in control group were given a equal volume of corn oil, once per day, five days per week for 12 weeks. The body weight of mice was measured during the experiment. After 12 weeks, all mice in each group were sacrificed. Plasma was collected and the levels of biochemical parameters were measured. Liver tissues were separated for examination of lipid deposition using oil red O and hematoxylin-eosin staining, and plasma triglyceride levels were measured. Real-time fluorescence quantitative polymerase chain reaction was used to detect the mRNA relative expression of genes of fat metabolism in liver tissues. RESULTS: At the end of the experiment, the body weights of mice were higher than that before the experiment(all P<0.05), but there was no statistically significant difference in body weights among the four groups(all P>0.05). The levels of plasma glucose, triglyceride and activity of alanine aminotransferase were higher in shifted photoperiod mice than that in the fixed photoperiod mice(all P<0.05). The plasma aspartate transaminase level was higher in BAP group than that in control group(P<0.01). The area of lipid staining in hepatic tissue was larger in the shifted photoperiod control group, fixed photoperiod BPA group and shifted photoperiod BPA group(all P<0.05), and hepatic lipid droplets aggregation was increased in these three groups compared with the fixed photoperiod control group. The mRNA relative expression of acetyl-coenzyme A carboxylase alpha(Acaca) was higher in the fixed photoperiod BPA and shifted photoperiod control groups(all P<0.05), compared with the fixed photoperiod control group. The relative expression of Acaca mRNA was lower in the shifted photoperiod BPA group than that in the fixed photoperiod BPA group(P<0.05). The mRNA relative expression of sterol regulatory element binding protein(Srebp) 1 and Srebp2 were significantly higher in the BPA group than that in the control group(all P<0.05). CONCLUSION: Both the single shifted photoperiod or BPA exposure can increase hepatic lipid deposition in female mice. The mechanism may be related to up-regulation of the mRNA expression of Acaca, Srebp1 and Srebp2. The shifted photoperiod in combination of BPA exposure has an antagonistic effect on the expression of Acaca mRNA in liver tissues of female mice.