Dioxins are endocrine-disrupting chemicals, and their effects on reproductive functions are well-documented. The aim of the present study was to measure the levels of reproductive hormones in 42 men ...residing near a dioxin-contaminated area in Vietnam. We measured levels of 17 2,3,7,8-substituted congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and four non-ortho polychlorinated biphenyls (PCBs) in blood. Levels of follicle-stimulating hormone, luteinizing hormone, progesterone, prolactin, estradiol, and total testosterone were measured in serum. Blood dioxin levels were elevated; the levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin was 7.3pg/g fat. Seven of the men had testosterone levels below 250ng/dL, and nine men had prolactin levels above 9.7ng/mL. Four PCDD congeners, two PCDF congeners, one PCB congener, and the sum TEQ of PCDDs, PCDDs/Fs, and PCDDs/Fs/PCBs were positively and significantly correlated with prolactin levels. Two PCDD congeners, six PCDF congeners, two PCB congeners, and the TEQs of PCDFs and PCBs were negatively and significantly correlated with testosterone levels. There were no significant correlations between dioxin congeners and follicle-stimulating hormone, luteinizing hormone, or progesterone levels.
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•We studied the effects of dioxin on reproductive hormone levels in Vietnamese men.•Dioxin and total testosterone levels were negatively correlated.•Dioxin and prolactin levels were positively correlated.•Future studies should assess dioxins' effects on the endocrine system as a whole.
•Scrub typhus, caused by O. tsutsugamushi, is a common fever in Southeast Asia.•Delayed diagnosis of scrub typhus leads to high mortality rates, of up to 70%.•Primers and probe are designed to be ...specific to Southeast Asia's O. tsutsugamushi.•Developed RPA assay showed high sensitivity and high specificity.•Developed RPA assay is promising for field testing.
Scrub typhus, caused by Orientia tsutsugamushi, is a common fever in parts of Southern and Southeast Asia. As delayed diagnosis of scrub typhus leads to inappropriate treatment and high mortality rates, of up to 70%, sensitive and rapid detection of O. tsutsugamushi is required for timely and appropriate treatment. Molecular assays, such as PCR and real-time PCR, have been shown to be more sensitive than conventional immunoassay, however, they are only available in centralized laboratories. In contrast to PCR assays, Recombinase Polymerase Amplification (RPA) is conducted under a constant temperature ranging from 24°C to 45°C. Therefore, this technology is very promising for nucleic acid testing in the field, and in resource-limited areas. An RPA assay for the detection of O. tsutsugamushi based on the target gene encoding for the 47 kDa outer membrane protein has been reported, but the primer and probe sequences of this assay are suboptimal for detection of the majority of recently published sequences of O. tsutsugamushi isolates from Southeast Asia. We have established a real-time RPA assay with primer and probe sequences that are optimized for most Southeast Asia's isolates of O. tsutsugamushi. As a result, the new RPA assay showed better performance than the previous assay in detecting O. tsutsugamushi in clinical samples of scrub typhus cases found in Vietnam. The specificity of RPA assay was also evaluated using genomic DNA from microorganisms commonly encountered in the differential diagnosis of scrub typhus, and blood samples from healthy controls and O. tsutsugamushi negative confirmed cases.
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We have followed a birth cohort from 2008 to 2009 near a dioxin-contaminated area of Da Nang, Vietnam, and investigated the effects of perinatal dioxin exposure on neurodevelopment from infancy to ...pre-school age. The present study aimed to investigate the effects of perinatal dioxin exposure on the learning abilities of the elementary-school children from the Da Nang birth cohort.
From 241 mother–infant pairs recruited at baseline (134 boys and 107 girls), 185 (76.8%) participated in a follow-up when the children were 8 years of age (108 boys and 77 girls). The children's perinatal dioxin exposure was estimated using the dioxin levels in their mothers' breast milk. The Colorado Learning Difficulties Questionnaire (CLDQ) was used to evaluate the children's learning difficulties. Math- and language-achievement scores were obtained using paper-based tests. Reading fluency was examined by having the children read passages in Vietnamese.
In boys exposed to high levels of 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TetraCDD), CLDQ reading scores were significantly higher (worse), and language achievement scores were significantly lower. Boys exposed to high levels of 2,3,7,8-TetraCDD as well as high levels of the toxic equivalent (TEQ) of polychlorodibenzodioxins and polychlorodibenzofurans (PCDDs/Fs) had higher numbers of reading errors. Reading errors were higher and math achievement scores were lower with increasing concentrations of 1,2,3,4,7,8-HexaCDD and 1,2,3,4,6,7,8-HeptaCDD. In girls, no significant differences of any learning ability markers were found between high and low exposure groups to TEQ-PCDDs/Fs and these 3 congeners.
Perinatal dioxin exposure may have adverse effects on the learning abilities of school children, especially boys.
Dioxin concentrations remain elevated in the environment and humans residing near the former US Air Force base in Bien Hoa city, South Vietnam. We recruited 210 mother-infant pairs for whom breast ...milk dioxin levels were reported in our previous study. Cord blood samples were collected from 162 mother-infant pairs. We selected 16 cord blood samples with a volume over 20mL and fat content of ≥0.03g. Toxic equivalent levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (TEQ-PCDD/Fs) and concentrations of 17 congeners, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), in cord blood were measured and compared with levels in breast milk (Study 1). Levels of 2,3,7,8-TCDD and TEQ-PCDD/Fs in cord blood samples were highly and significantly correlated with those in breast milk samples in the same pairs. This suggests dioxins in breast milk reflect prenatal dioxin exposure. Estradiol (E2) and testosterone (TS) were measured in cord blood serum from 162 samples. Associations between dioxins in breast milk and cord blood sex hormones were analyzed by infant sex, after adjusting for confounding factors (Study 2). Increased levels of TEQ-PCDD/Fs in breast milk were associated with decreased cord blood TS in girls. In boys, a significant reduction of cord blood TS was observed in those exposed to 2,3,7,8-TCDD at high levels (≥5.5pg/g lipid). There was no significant association between E2 and dioxins in breast milk in either sex. These results suggest increased prenatal dioxin exposure is associated with decreased cord TS, but in boys, only high level of 2,3,7,8-TCDD influence cord blood TS.
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•Dioxins in breast milk are good indicators of prenatal dioxin exposure to fetus.•Increased prenatal dioxin exposure may decrease cord blood testosterone level.•High level of 2,3,7,8-TCDD may influence cord blood TS in boys.
This study looked to identify determinants of exposure to dioxin in breast milk from breast-feeding women in a hot spot of dioxin exposure in Vietnam. Breast milk was collected from 140 mothers 1 ...month after delivery. The risk factors investigated included length of residency, drinking of well water and the frequency of animal food consumption. Cluster analysis was performed to identify dietary patterns of fish and meat portions, fish variety and egg variety. Residency, age and parity were clearly associated with increased dioxin levels. Drinking well water and the consumption of marine crab and shrimps were related to higher levels of furans in breast milk. The consumption of quail eggs also appeared to be associated with increased levels of some dioxin isomers in this area. Some mothers who ate no or less meat than fish and mothers who consumed more freshwater fish than marine fish had lower levels of dioxins in their breast milk. However, the type of water and the eating habits of mothers contributed only partly to the increased dioxin levels in their breast milk; the length of residency was the most important risk factor associated with increased dioxin body burdens of mothers.
Bien Hoa Air Base is the largest dioxin contamination hot spot in Vietnam. In 2012, we recruited 216 mothers who were living in 10 communities around Bien Hoa Air Base and had delivered newborns at a ...prefecture hospital, and we investigated recent exposure levels of dioxins and nonortho PCBs in their breast milk. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD) was present at 2.6 pg/g lipid in primiparae and 2.2 pg/g lipid in multiparae. Among multiparae and total subjects, significant high prevalence of 2,3,7,8-tetraCDD ≥ 5 pg/g lipid and 2,3,7,8-tetraCDD contribution ≥ 40% were observed in mothers living in the five communities closest to Bien Hoa Air Base. The TEQ for nonortho PCBs was 1.6 pg-TEQ/g lipid for primiparae, and this was even lower than that in the unsprayed area. The length of residency was a strong factor to increase dioxins, including 2,3,7,8-tetraCDD. Residency in the five communities with the highest exposure was a specific risk factor for increased 2,3,7,8-tetraCDD in breast milk. Food intake might contribute partly to the increased levels of dioxin congeners other than 2,3,7,8-tetraCDD in breast milk. These results suggest that Bien Hoa Air Base has led to elevated 2,3,7,8-tetraCDD levels in breast milk of mothers in nearby areas even in the recent years.
We evaluated an absorbance effectiveness on the solar spectrum using an absorption figure of merit (a-FOM) for the conducting thin films. In particular, Ni-doped and un-doped CuO thin films were ...deposited by a facile and sustainable solution-processed synthesis, whose Ni doping concentration was varied to be 0.2, 0.6, 1, 2, 3, 4 wt%. We observed a change of smooth surface to an appearance of nanoparticles by Ni doping, which supported to form of a plasmonic mechanism for improving the light capture and retention. The absorption of long wavelengths was improved and extended to the near-infrared range. That is, the bandgap energy decreased from 2.10 to 1.88 eV with Ni doping. Also, we found that the absorption length decreased from 99.93 nm to 63.80 nm as the Ni doping increased. In addition, the CuO-based film with 4 wt% Ni doping showed a maximal value of a-FOM as high as 30.88 Ω−1cm−1, corresponding to a resistance of 2.07 MΩ/sq and an absorption length of 63.80 nm. Our finding suggested that Ni-doped CuO thin films can be considered as an excellent selection of absorbent conductive oxide layers for application in optoelectronic devices and solar cell systems.
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•Ni doped CuO thin films exhibited a co-existence of two separated phases.•Density of nanoparticles on the films surface increased with Ni doping concentration, preferable to the absorption improvement.•Bandgap energy and electrical resistivity of the Ni doped CuO thin films reduced with increasing of the Ni concentration.•The absorption figure of merit enhanced with Ni doping, and reached to the highest value for the case of 4 wt% doped.
Clinical progression of HBV-related liver diseases is largely associated with the activity of HBV-specific T cells. Soluble fibrinogen-like protein 2 (sFGL2), mainly secreted by T cells, is an ...important effector molecule of the immune system.
sFGL2 levels were determined by ELISA assays in sera of 296 HBV patients clinically classified into the subgroups of acute hepatitis B (AHB), chronic hepatitis B (CHB), liver cirrhosis (LC), hepatocellular carcinoma (HCC) and patients with LC plus HCC. As control group, 158 healthy individuals were included. FGL2 mRNA was quantified by qRT-PCR in 32 pairs of tumor and adjacent non-tumor liver tissues.
sFGL2 levels were elevated in HBV patients compared to healthy controls (P < 0.0001). In the patient group, sFGL2 levels were increased in AHB compared to CHB patients (P = 0.017). sFGL2 levels were higher in LC patients compared to those without LC (P = 0.006) and were increased according to the development of cirrhosis as staged by Child-Pugh scores (P = 0.024). Similarly, HCC patients had increased sFGL2 levels compared to CHB patients (P = 0.033) and FGL2 mRNA was up-regulated in tumor tissues compared to adjacent non-tumor tissues (P = 0.043). In addition, sFGL2 levels were positively correlated with HBV-DNA loads and AST (Spearman's rho = 0.21, 0.25 and P = 0.006, 0.023, respectively), but reversely correlated with platelet counts and albumin levels (Spearman's rho = - 0.27, - 0.24 and P = 0.014, 0.033, respectively).
sFGL2 levels are induced by HBV infection and correlated with the progression and clinical outcome of HBV-related liver diseases. Thus, sFGL2 may serve as a potential indicator for HBV-related liver diseases.
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