DDT (2,2,bis(p-chlorophenyl) 1,1,1-trichloroethane) induced structural changes in adrenal glands of rats

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, A.R.; Gautam, A.K.; Venkatakrishna-Bhatt, H. (National Institute of Occupational Health, Ahmedabad (India))

1990-08-01

Oldest chlorinated hydrocarbon insecticide, DDT was used widely to control pest and vector borne diseases in developing countries. Malaria and vector borne diseases can be econometrically controlled by DDT. Chronic and acute exposures to DDT result in systemic disorders in human as well as this confirmed in animals. Experimental study revealed that DDT caused the structural and functional changes in thyroid and reproductive system. The effects of DDT on adrenal glands are not well documented. Therefore this experimental investigation was undertaken to evaluate the histomorphological changes of adrenal gland after the treatment with DDT in rats.

Synthesis of the DDT metabolite 2,4-dichloro-1-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene (o-Cl-DDMU) and its detection in abiotic and biotic samples.

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Gallistl, Christoph; Proctor, Katie; Bader, Korinna; Vetter, Walter

2017-07-01

Technical dichlorodiphenyltrichloroethane (DDT) has been used worldwide as a pesticide since the beginning of the 1940s. Due to its persistence, DDT residues are still ubiquitously distributed in the environment. Photochemical UV degradation has been shown to be a potent degradation path for DDT and most of the resulting photoproducts have been identified up to now. Nevertheless, in 2012, a new DDT metabolite, most likely formed photochemically from DDE, was detected in ray liver samples from Brazil, an area which is highly contaminated with DDT. This study includes photochemical generation, chemical synthesis and isolation of this compound which was verified to consist of both cis- and trans-2,4-dichloro-1-[2-chloro-1-(4-chlorophenyl)ethenyl]benzene. Both stereoisomers were resolved by gas chromatography on a polar capillary column and detected in more than 60 biotic (e.g. marine mammals, birds, human milk) and abiotic samples (fat deposits in kitchen hoods) from different areas all over the world. The stereoisomer distribution and concentrations (0.3-3.9% relative to corresponding 1,1-dichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDE) levels) were determined by means of the synthesized analytical standard, indicating the widespread occurrence of this compound as an additional minor metabolite of DDT.

Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

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Norris, J S; Kohler, P O

1978-01-01

Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

Intercellular communication and cell proliferation in precision-cut rat liver slices : effect of medium composition and DDT

NARCIS (Netherlands)

Graaf, I.A.M.; Tajima, O.; Groten, J.P.; Wolterbeek, A.P.M.

2000-01-01

Gap junctional intercellular communication (GJIC) and cell proliferation were studied in control and 1,1'-bis(p-chlorophenyl)-2,2,2,-trichloroethane (DDT) treated precision-cut liver slices of rat by evaluating connexin 32 (Cx32) expression and 5-bromo-2'-deoxyuridine (BrdU) incorporation. In

The effect of DDT and its metabolite (DDE) on prostaglandin secretion from epithelial cells and on contractions of the smooth muscle of the bovine oviduct in vitro

International Nuclear Information System (INIS)

Wrobel, Michal H.; Mlynarczuk, Jaroslaw; Kotwica, Jan

2012-01-01

The insecticide DDT and its metabolite (DDE), due to their lipolytic nature and resistance to biodegradation, are accumulated in the living tissues. In cows, DDT and DDE were found to affect prostaglandin (PG) secretion from the endometrium and contractions of the myometrium. In this study, the impact of both xenobiotics (0.1, 1, 10 or 100 ng/ml) on the function of epithelial cells and muscle strips of bovine oviducts from 1 to 5 day of the oestrous cycle was examined. Therefore the concentration of PGE2 and PGFM (a metabolite of PGF2α) in culture media, mRNA expression of genes involved in PGs synthesis in epithelial cells and the force and amplitude of strips contractions were measured after 2 and 24 or 48 h of incubation. Neither DDT nor DDE affected the viability of cells after 48 h (P > 0.05). Both DDT and DDE increased the concentrations of PGFM in culture medium and secretion of PGE2 after only 2 h of cell culture (P < 0.05). Similar effects were seen for the influence of DDE on amount of PGFM after 48 h, while DDT decreased secretion of PGE2 (P < 0.05). DDT after 2 h increased (P < 0.05) mRNA expression of PGF2α synthase (PGFS), while both xenobiotics decreased (P < 0.05) mRNA expression of cyclooxygenase-2 (COX-2) after 24 h. DTT also increased the force of isthmus contractions after 2 h, as did both xenobiotics after 48 h (P < 0.05). Moreover, after 2 and 48 h, DDE stimulated the amplitude of contractions of the isthmus as well as the ampulla, (P < 0.05). The effect of both compounds on oviduct contractions was diminished by indomethacin, which blocks PG synthesis. We conclude that oviductal secretion of prostaglandins is affected, by DDT and DDE. The influence of these xenobiotics on PGF2α and PGE2 secretion and ratio may be part of the mechanism by which both DDT and its metabolite disturb the contractions of oviductal muscle. -- Highlights: ► DDT and its metabolite – DDE are accumulated in the living tissues. ► The insecticides affected PGF2�

Depressive-like effect of prenatal exposure to DDT involves global DNA hypomethylation and impairment of GPER1/ESR1 protein levels but not ESR2 and AHR/ARNT signaling.

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Kajta, Malgorzata; Wnuk, Agnieszka; Rzemieniec, Joanna; Litwa, Ewa; Lason, Wladyslaw; Zelek-Molik, Agnieszka; Nalepa, Irena; Rogóż, Zofia; Grochowalski, Adam; Wojtowicz, Anna K

2017-07-01

Several lines of evidence suggest that exposures to Endocrine Disrupting Chemicals (EDCs) such as pesticides increase the risks of neuropsychiatric disorders. Despite extended residual persistence of dichlorodiphenyltrichloroethane (DDT) in the environment, the mechanisms of perinatal actions of DDT that could account for adult-onset of depression are largely unknown. This study demonstrated the isomer-specific induction of depressive-like behavior and impairment of Htr1a/serotonin signaling in one-month-old mice that were prenatally exposed to DDT. The effects were reversed by the antidepressant citalopram as evidenced in the forced swimming (FST) and tail suspension (TST) tests in the male and female mice. Prenatally administered DDT accumulated in mouse brain as determined with gas chromatography and tandem mass spectrometry, led to global DNA hypomethylation, and altered the levels of methylated DNA in specific genes. The induction of depressive-like behavior and impairment of Htr1a/serotonin signaling were accompanied by p,p'-DDT-specific decrease in the levels of estrogen receptors i.e. ESR1 and/or GPER1 depending on sex. In contrast, o,p'-DDT did not induce depressive-like effects and exhibited quite distinct pattern of biochemical alterations that was related to aryl hydrocarbon receptor (AHR), its nuclear translocator ARNT, and ESR2. Exposure to o,p'-DDT increased AHR expression in male and female brains, and reduced expression levels of ARNT and ESR2 in the female brains. The evolution of p,p'-DDT-induced depressive-like behavior was preceded by attenuation of Htr1a and Gper1/GPER1 expression as observed in the 7-day-old mouse pups. Because p,p'-DDT caused sex- and age-independent attenuation of GPER1, we suggest that impairment of GPER1 signaling plays a key role in the propagation of DDT-induced depressive-like symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estrogenic Activity of Coumestrol, DDT, and TCDD in Human Cervical Cancer Cells

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Kenneth Ndebele

2010-05-01

Full Text Available Endogenous estrogens have dramatic and differential effects on classical endocrine organ and proliferation. Xenoestrogens are environmental estrogens that have endocrine impact, acting as both estrogen agonists and antagonists, but whose effects are not well characterized. In this investigation we sought to delineate effects of xenoestrogens. Using human cervical cancer cells (HeLa cells as a model, the effects of representative xenoestrogens (Coumestrol-a phytoestrogen, tetrachlorodioxin (TCDD-a herbicide and DDT-a pesticide on proliferation, cell cycle, and apoptosis were examined. These xenoestrogens and estrogen inhibited the proliferation of Hela cells in a dose dependent manner from 20 to 120 nM suggesting, that 17-β-estrtadiol and xenoestrogens induced cytotoxic effects. Coumestrol produced accumulation of HeLa cells in G2/M phase, and subsequently induced apoptosis. Similar effects were observed in estrogen treated cells. These changes were associated with suppressed bcl-2 protein and augmented Cyclins A and D proteins. DDT and TCDD exposure did not induce apoptosis. These preliminary data taken together, suggest that xenoestrogens have direct, compound-specific effects on HeLa cells. This study further enhances our understanding of environmental modulation of cervical cancer.

Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes

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Zhu, Zhi-qiang [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Zijingang Campus, Hangzhou 310058 (China); College of Agriculture, Hainan University, Renmin Road 58, Haikou 570228 (China); Yang, Xiao-e, E-mail: xyang@zju.edu.cn [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Zijingang Campus, Hangzhou 310058 (China); Wang, Kai; Huang, Hua-gang; Zhang, Xincheng [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Zijingang Campus, Hangzhou 310058 (China); Fang, Hua [Department of Plant Protection, College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058 (China); Li, Ting-qiang [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Zijingang Campus, Hangzhou 310058 (China); Alva, A.K. [U.S. Department of Agriculture-Agricultural Research Service, Prosser, WA (United States); He, Zhen-li [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Planting of S. alfredii is an effective technique for phytoextraction of Cd and DDs. Black-Right-Pointing-Pointer Soil inoculation with Pseudomonas sp. DDT-1 increases root biomass of S. alfredii. Black-Right-Pointing-Pointer Soil inoculation with Pseudomonas sp. DDT-1 improves the removal efficiency of DDs. Black-Right-Pointing-Pointer The plant-microbe strategy is promising for remediation of Cd-DDT co-contaminated soil. - Abstract: The development of an integrated strategy for the remediation of soil co-contaminated by heavy metals and persistent organic pollutants is a major research priority for the decontamination of soil slated for use in agricultural production. The objective of this study was to develop a bioremediation strategy for fields co-contaminated with cadmium (Cd), dichlorodiphenyltrichloroethane (DDT), and its metabolites 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethylene (DDE) and 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethane (DDD) (DDT, DDE, and DDD are collectively called DDs) using an identified Cd-hyperaccumulator plant Sedum alfredii (SA) and DDT-degrading microbes (DDT-1). Initially, inoculation with DDT-1 was shown to increase SA root biomass in a pot experiment. When SA was applied together with DDT-1, the levels of Cd and DDs in the co-contaminated soil decreased by 32.1-40.3% and 33.9-37.6%, respectively, in a pot experiment over 18 months compared to 3.25% and 3.76% decreases in soil Cd and DDs, respectively, in unplanted, untreated controls. A subsequent field study (18-month duration) in which the levels of Cd and DDs decreased by 31.1% and 53.6%, respectively, confirmed the beneficial results of this approach. This study demonstrates that the integrated bioremediation strategy is effective for the remediation of Cd-DDs co-contaminated soils.

Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes

International Nuclear Information System (INIS)

Zhu, Zhi-qiang; Yang, Xiao-e; Wang, Kai; Huang, Hua-gang; Zhang, Xincheng; Fang, Hua; Li, Ting-qiang; Alva, A.K.; He, Zhen-li

2012-01-01

Highlights: ► Planting of S. alfredii is an effective technique for phytoextraction of Cd and DDs. ► Soil inoculation with Pseudomonas sp. DDT-1 increases root biomass of S. alfredii. ► Soil inoculation with Pseudomonas sp. DDT-1 improves the removal efficiency of DDs. ► The plant-microbe strategy is promising for remediation of Cd-DDT co-contaminated soil. - Abstract: The development of an integrated strategy for the remediation of soil co-contaminated by heavy metals and persistent organic pollutants is a major research priority for the decontamination of soil slated for use in agricultural production. The objective of this study was to develop a bioremediation strategy for fields co-contaminated with cadmium (Cd), dichlorodiphenyltrichloroethane (DDT), and its metabolites 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethylene (DDE) and 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethane (DDD) (DDT, DDE, and DDD are collectively called DDs) using an identified Cd-hyperaccumulator plant Sedum alfredii (SA) and DDT-degrading microbes (DDT-1). Initially, inoculation with DDT-1 was shown to increase SA root biomass in a pot experiment. When SA was applied together with DDT-1, the levels of Cd and DDs in the co-contaminated soil decreased by 32.1–40.3% and 33.9–37.6%, respectively, in a pot experiment over 18 months compared to 3.25% and 3.76% decreases in soil Cd and DDs, respectively, in unplanted, untreated controls. A subsequent field study (18-month duration) in which the levels of Cd and DDs decreased by 31.1% and 53.6%, respectively, confirmed the beneficial results of this approach. This study demonstrates that the integrated bioremediation strategy is effective for the remediation of Cd-DDs co-contaminated soils.

Low Concentrations of o,p’-DDT Inhibit Gene Expression and Prostaglandin Synthesis by Estrogen Receptor-Independent Mechanism in Rat Ovarian Cells

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Liu, Jing; Zhao, Meirong; Zhuang, Shulin; Yang, Yan; Yang, Ye; Liu, Weiping

2012-01-01

o,p’-DDT is an infamous xenoestrogen as well as a ubiquitous and persistent pollutant. Biomonitoring studies show that women have been internally exposed to o,p’-DDT at range of 0.3–500 ng/g (8.46×10−10 M−1.41×10−6 M) in blood and other tissues. However, very limited studies have investigated the biological effects and mechanism(s) of o,p’-DDT at levels equal to or lower than current exposure levels in human. In this study, using primary cultures of rat ovarian granulosa cells, we determined that very low doses of o,p’-DDT (10−12−10−8 M) suppressed the expression of ovarian genes and production of prostaglandin E2 (PGE2). In vivo experiments consistently demonstrated that o,p’-DDT at 0.5–1 mg/kg inhibited the gene expression and PGE2 levels in rat ovary. The surprising results from the receptor inhibitors studies showed that these inhibitory effects were exerted independently of either classical estrogen receptors (ERs) or G protein-coupled receptor 30 (GPR30). Instead, o,p’-DDT altered gene expression or hormone action via inhibiting the activation of protein kinase A (PKA), rather than protein kinase C (PKC). We further revealed that o,p’-DDT directly interfered with the PKA catalytic subunit. Our novel findings support the hypothesis that exposure to low concentrations of o,p’-DDT alters gene expression and hormone synthesis through signaling mediators beyond receptor binding, and imply that the current exposure levels of o,p’-DDT observed in the population likely poses a health risk to female reproduction. PMID:23209616

In Vitro Effects of the Endocrine Disruptor p,p’-DDT on Human Follitropin Receptor

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Munier, Mathilde; Grouleff, Julie; Gourdin, Louis; Fauchard, Mathilde; Chantreau, Vanessa; Henrion, Daniel; Coutant, Régis; Schiøtt, Birgit; Chabbert, Marie; Rodien, Patrice

2016-01-01

Background: 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene (p,p′-DDT) is a persistent environmental endocrine disruptor (ED). Several studies have shown an association between p,p′-DDT exposure and reproductive abnormalities. Objectives: To investigate the putative effects of p,p′-DDT on the human follitropin receptor (FSHR) function. Methods and Results: We used Chinese hamster ovary (CHO) cells stably expressing human FSHR to investigate the impact of p,p′-DDT on FSHR activity and its interaction with the receptor. At a concentration of 5 μM p,p′-DDT increased the maximum response of the FSHR to follitropin by 32 ± 7.45%. However, 5 μM p,p′-DDT decreased the basal activity and did not influence the maximal response of the closely related LH/hCG receptor to human chorionic gonadotropin (hCG). The potentiating effect of p,p′-DDT was specific for the FSHR. Moreover, in cells that did not express FSHR, p,p′-DDT had no effect on cAMP response. Thus, the potentiating effect of p,p′-DDT was dependent on the FSHR. In addition, p,p′-DDT increased the sensitivity of FSHR to hCG and to a low molecular weight agonist of the FSHR, 3-((5methyl)-2-(4-benzyloxy-phenyl)-5-{[2-[3-ethoxy-4-methoxy-phenyl)-ethylcarbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-benzamide (16a). Basal activity in response to p,p′-DDT and potentiation of the FSHR response to FSH by p,p′-DDT varied among FSHR mutants with altered transmembrane domains (TMDs), consistent with an effect of p,p′-DDT via TMD binding. This finding was corroborated by the results of simultaneously docking p,p′-DDT and 16a into the FSHR transmembrane bundle. Conclusion: p,p′-DDT acted as a positive allosteric modulator of the FSHR in our experimental model. These findings suggest that G protein–coupled receptors are additional targets of endocrine disruptors. Citation: Munier M, Grouleff J, Gourdin L, Fauchard M, Chantreau V, Henrion D, Coutant R, Schiøtt B, Chabbert M, Rodien P. 2016

Sequelae in male rabbits following developmental exposure to p,p'-DDT or a mixture of p,p'-DDT and vinclozolin: cryptorchidism, germ cell atypia, and sexual dysfunction.

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Veeramachaneni, D N R; Palmer, J S; Amann, R P; Pau, K-Y F

2007-01-01

Rabbit does (7-9 per group) were treated daily per orum from gestation day 15 through post-natal week 4 to provide per kg body wt 25 micaromol (low) or 250 micromol (high) p,p'-DDT or a mixture of DDT and vinclozolin (12.5 and 125 micromol each). Developmental as well as post-pubertal reproductive sequelae of male progeny were studied. Testicular descent in some pups was impaired by DDT. Serum LH or testosterone was not affected. FSH was lower in mixture- but not in DDT-exposed rabbits. Lack of sexual interest, penile erection and ejaculation were observed in some mixture rabbits. Sperm counts were unaffected, but morphologically normal spermatozoa were fewer; nuclear and acrosomal morphogenesis was disrupted. Atypical germ cells resembling carcinoma in situ were found. Also considering data for vinclozolin [Veeramachaneni DNR, Palmer JS, Amann RP, Kane CM, Higuchi TT, Pau K-YF. Disruption of sexual function, FSH secretion, and spermiogenesis in rabbits following developmental exposure to vinclozolin, a fungicide. Reproduction 2006;131:805-16], we concluded that DDT causes cryptorchidism and germ cell atypia, vinclozolin permanently disrupts FSH secretion and sexual function, and the mixture causes the full spectrum of dysgenesis.

Influence of arsenic co-contamination on DDT breakdown and microbial activity

International Nuclear Information System (INIS)

Zwieten, Lukas van; Ayres, Matthew R.; Morris, Stephen G.

2003-01-01

Co-occurrence of arsenic and DDT in soil may result increased persistence of DDT. - The impacts of arsenic co-contamination on the natural breakdown of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) in soil are investigated in a study of 12 former cattle dip sites located in northeastern NSW, Australia. This study examines the relationship between the intrinsic breakdown of DDT to 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), and the impacts of arsenic co-contamination on this breakdown. Between-site analysis demonstrated that arsenic at 2000 mg/kg gave a 50% reduction in the concentration of DDD compared to background arsenic of 5 mg/kg. Within-site analysis also showed the ratio of DDT:DDD increased in soils as arsenic concentrations increased. This within-site trend was also apparent with the DDT:DDE ratio, suggesting inhibition of DDT breakdown by arsenic co-contamination. Microbial activity was inhibited as residues of total DDTs and arsenic increased. Hence arsenic co-contamination and high concentrations of DDT in soil may result in an increased persistence of DDT in the environment studied

Destructive examination of test plates 1 and 2 of the defects detection trials (DDT)

International Nuclear Information System (INIS)

Crutzen, S.; Buegers, W.; Violin, F.; Di Piazza, L.; Cowburn, K.; Sargent, T.

1984-01-01

The evaluation of NDT exercises results has been based on destructive examination of the plates or test blocks used during the exercise. The PISC Programme has shown that in all cases the indications given by the NDT instrumentation were corresponding to some particular defects or structure aspects in the steel or were explained by particular positions of reflectors. Generally the introduction of defects do not produce a final ''defective zone or area'' which is strictly corresponding to the intended defect. The DDT exercise management has thus decided to perform a complete destructive examination of the four plates involved in this exercise because of its experience (the PISC I exercise) and independance of commercial interest, the JRC of the CEC Ispra Establishment has been asked to do the work with the Risley Nuclear Power Development Laboratories (RNL). The present report describes the results of the destructive examination of the DDT plates 1 and 2

p,p'-DDT induces testicular oxidative stress-induced apoptosis in adult rats.

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Marouani, Neila; Hallegue, Dorsaf; Sakly, Mohsen; Benkhalifa, Moncef; Ben Rhouma, Khémais; Tebourbi, Olfa

2017-05-26

The 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT) is a known persistent organic pollutant and male reproductive toxicant. The present study is designed to test the hypothesis that oxidative stress mediates p,p'-DDT-induced apoptosis in testis. Male Wistar rats received an intraperitoneal (ip) injection of the pesticide at doses of 50 and 100mg/kg for 10 consecutive days. The oxidative stress was evaluated by biomarkers such lipid peroxidation (LPO) and metallothioneins (MTs) levels. Antioxidant enzymes activities was assessed by determination of superoxide dismutase (SOD), catalase (CAT) and hydrogen peroxide (H 2 O 2 ) production. In addition, glutathione-dependent enzymes and reducing power in testis was evaluated by glutathione peroxidase (Gpx), glutathione reductase (GR), glutathione S-transferase (GST) activities and reduced and oxidized glutathione (GSH - GSSG) levels. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis. Germinal cells apoptosis and the apoptotic index was assessed through the TUNEL assay. After 10 days of treatment, an increase in LPO level and H 2 O 2 production occurred, while MTs level, SOD and CAT activities were decreased. Also, the Gpx, GR, GST, and GSH activities were decreased, whereas GSSG activity was increased. Testicular tissues of treated rats showed pronounced degradation of the DNA into oligonucleotides as seen in the typical electrophoretic DNA ladder pattern. Intense apoptosis was observed in germinal cells of DDT-exposed rats. In addition, the apoptotic index was significantly increased in testis of DDT-treated rats. These results clearly suggest that DDT sub-acute treatment causes oxidative stress in rat testis leading to apoptosis.

Fasciola spp: Mapping of the MF6 epitope and antigenic analysis of the MF6p/HDM family of heme-binding proteins.

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Victoria Martínez-Sernández

Full Text Available MF6p/FhHDM-1 is a small cationic heme-binding protein which is recognized by the monoclonal antibody (mAb MF6, and abundantly present in parenchymal cells and secreted antigens of Fasciola hepatica. Orthologs of this protein (MF6p/HDMs also exist in other causal agents of important foodborne trematodiasis, such as Clonorchis sinensis, Opisthorchis viverrini and Paragonimus westermani. Considering that MF6p/FhHDM-1 is relevant for heme homeostasis in Fasciola and was reported to have immunomodulatory properties, this protein is expected to be a useful target for vaccination. Thus, in this study we mapped the epitope recognized by mAb MF6 and evaluated its antigenicity in sheep. The sequence of the MF6p/FhHDM-1 ortholog from F. gigantica (MF6p/FgHDM-1 was also reported. By means of ELISA inhibitions with overlapping synthetic peptides, we determined that the epitope recognized by mAb MF6 is located within the C-terminal moiety of MF6p/FhHDM-1, which is the most conserved region of MF6p/HDMs. By immunoblotting analysis of parasite extracts and ELISA inhibitions with synthetic peptides we also determined that mAb MF6 reacted with the same intensity with F. hepatica and F. gigantica, and in decreasing order of intensity with C. sinensis, O.viverrini and P. westermani orthologs. On the contrary, mAb MF6 showed no reactivity against Dicrocoelium dendriticum and Schistosoma mansoni. The study of the recognition of peptides covering different regions of MF6p/FhHDM-1 by sera from immunized sheep revealed that the C-terminal moiety is the most antigenic, thus being of potential interest for vaccination. We also demonstrated that the production of antibodies to MF6p/FhHDM-1 in sheep infected by F. hepatica occurs relatively early and follows the same pattern as those produced against L-cathepsins.

Vaccine adjuvant MF59 promotes the intranodal differentiation of antigen-loaded and activated monocyte-derived dendritic cells.

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Rossella Cioncada

Full Text Available MF59 is an oil-in-water emulsion adjuvant approved for human influenza vaccination in European Union. The mode of action of MF59 is not fully elucidated yet, but results from several years of investigation indicate that MF59 establishes an immunocompetent environment at injection site which promotes recruitment of immune cells, including antigen presenting cells (APCs, that are facilitated to engulf antigen and transport it to draining lymph node (dLN where the antigen is accumulated. In vitro studies showed that MF59 promotes the differentiation of monocytes to dendritic cells (Mo-DCs. Since after immunization with MF59, monocytes are rapidly recruited both at the injection site and in dLN and appear to have a morphological change toward a DC-like phenotype, we asked whether MF59 could play a role in inducing differentiation of Mo-DC in vivo. To address this question we immunized mice with the auto-fluorescent protein Phycoerythrin (PE as model antigen, in presence or absence of MF59. We measured the APC phenotype and their antigen uptake within dLNs, the antigen distribution within the dLN compartments and the humoral response to PE. In addition, using Ovalbumin as model antigen, we measured the capacity of dLN APCs to induce antigen-specific CD4 T cell proliferation. Here, we show, for the first time, that MF59 promotes differentiation of Mo-DCs within dLNs from intranodal recruited monocytes and we suggest that this differentiation could take place in the medullary compartment of the LN. In addition we show that the Mo-DC subset represents the major source of antigen-loaded and activated APCs within the dLN when immunizing with MF59. Interestingly, this finding correlates with the enhanced triggering of antigen-specific CD4 T cell response induced by LN APCs. This study therefore demonstrates that MF59 is able to promote an immunocompetent environment also directly within the dLN, offering a novel insight on the mechanism of action of

Accelerated anaerobic dechlorination of DDT in slurry with Hydragric Acrisols using citric acid and anthraquinone-2,6-disulfonate (AQDS).

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Liu, Cuiying; Xu, Xianghua; Fan, Jianling

2015-12-01

The application of electron donor and electron shuttle substances has a vital influence on electron transfer, thus may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in anaerobic reaction systems. To evaluate the roles of citric acid and anthraquinone-2,6-disulfonate (AQDS) in accelerating the reductive dechlorination of DDT in Hydragric Acrisols that contain abundant iron oxide, a batch anaerobic incubation experiment was conducted in a slurry system with four treatments of (1) control, (2) citric acid, (3) AQDS, and (4) citric acid+AQDS. Results showed that DDT residues decreased by 78.93%-92.11% of the initial quantities after 20days of incubation, and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane (DDD) was the dominant metabolite. The application of citric acid accelerated DDT dechlorination slightly in the first 8days, while the methanogenesis rate increased quickly, and then the acceleration effect improved after the 8th day while the methanogenesis rate decreased. The amendment by AQDS decreased the Eh value of the reaction system and accelerated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus enhancing the reductive dechlorination rate of DDT. The addition of citric acid+AQDS was most efficient in stimulating DDT dechlorination, but no significant interaction between citric acid and AQDS on DDT dechlorination was observed. The results will be of great significance for developing an efficient in situ remediation strategy for DDT-contaminated sites. Copyright © 2015. Published by Elsevier B.V.

4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) inhibit myogenesis in C2C12 myoblasts.

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Kim, Jonggun; Park, Min Young; Kim, Yoo; Yoon, Kyong Sup; Clark, John Marshall; Park, Yeonhwa; Whang, Kwang-Youn

2017-12-01

Most countries have banned the use of 4,4'-dichlorodiphenyltrichloroethane (DDT). However, owing to its extremely high lipophilic characteristics, DDT and its metabolite 4,4'-dichlorodiphenyldichloroethylene (DDE) are ubiquitous in the environment and in many types of food. The positive correlation between exposure to insecticides, including DDT and DDE, and weight gain, resulting in impaired energy metabolism in offspring following perinatal DDT and DDE exposure, was previously reported. Therefore the influence of DDT and DDE on myogenesis using C2C12 myoblasts was investigated in this study. DDT and DDE decreased myotube formation dose- and time-dependently. Among myogenic regulatory factors, DDT and DDE mainly decreased MyoD1 and Myf5 expression. DDT and DDE treatment also altered Myostatin expression, phosphorylation of protein kinase B, p70 ribosomal protein S6 kinase, forkhead box O protein 3 and mammalian target of rapamycin, resulting in attenuation of myotube formation. These results may have significant implications for understanding the effects of developmental exposure of DDT and DDE on myogenesis and development of obesity and type 2 diabetes later in life. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Nanoscale zerovalent iron-mediated degradation of DDT in soil.

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Han, Yuling; Shi, Nan; Wang, Huifang; Pan, Xiong; Fang, Hua; Yu, Yunlong

2016-04-01

Nanoscale zerovalent iron (nZVI)-mediated degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) was investigated in a spiked soil under different conditions (iron sources, iron dosage, soil moisture, temperature, and soil types) and DDT-contaminated field. The degradation efficiency of p,p'-DDT by nZVI and nZVI coated with sodium oleate (SO-nZVI) was much higher than that by nZVI coated with polyimide (PI-nZVI). The rapid degradation of p,p'-DDT by nZVI only occurred in flooded soil. The degradation half-life of p,p'-DDT decreased significantly from 58.3 to 27.6 h with nZVI dosage from 0.5 to 2.0% and from 46.5 to 32.0 h with temperature from 15 to 35 °C. The degradation efficiency of p,p'-DDT by nZVI differed in Jinhua (JH), Jiaxing (JX), Xiaoshan (XS), Huajiachi (HJC), and Heilongjiang (HLJ) soils. A good correlation was found between the degradation half-life of p,p'-DDT and multiple soil properties. The probable nZVI-mediated degradation pathway of p,p'-DDT in soil was proposed as DDT → DDD/DDE → DDNS → DDOH based on the metabolites identified by GC-MS. The in situ degradation efficiency of residual DDTs in a contaminated field was profoundly enhanced by the addition of nZVI as compared to the control. It is concluded that nZVI might be an efficient agent for the remediation of DDT-contaminated soil under anaerobic environment.

Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

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Guangli Wang

2010-06-01

Full Text Available Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenylethane (DDT is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95% of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60% of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenylethane (DDD, 2,2-bis(p-chlorophenyl-1,1-dichlorethylene (DDE, and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

ELF-MF exposure affects the robustness of epigenetic programming during granulopoiesis

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Manser, Melissa; Sater, Mohamad R. Abdul; Schmid, Christoph D.; Noreen, Faiza; Murbach, Manuel; Kuster, Niels; Schuermann, David; Schär, Primo

2017-03-01

Extremely-low-frequency magnetic fields (ELF-MF) have been classified as “possibly carcinogenic” to humans on the grounds of an epidemiological association of ELF-MF exposure with an increased risk of childhood leukaemia. Yet, underlying mechanisms have remained obscure. Genome instability seems an unlikely reason as the energy transmitted by ELF-MF is too low to damage DNA and induce cancer-promoting mutations. ELF-MF, however, may perturb the epigenetic code of genomes, which is well-known to be sensitive to environmental conditions and generally deranged in cancers, including leukaemia. We examined the potential of ELF-MF to influence key epigenetic modifications in leukaemic Jurkat cells and in human CD34+ haematopoietic stem cells undergoing in vitro differentiation into the neutrophilic lineage. During granulopoiesis, sensitive genome-wide profiling of multiple replicate experiments did not reveal any statistically significant, ELF-MF-dependent alterations in the patterns of active (H3K4me2) and repressive (H3K27me3) histone marks nor in DNA methylation. However, ELF-MF exposure showed consistent effects on the reproducibility of these histone and DNA modification profiles (replicate variability), which appear to be of a stochastic nature but show preferences for the genomic context. The data indicate that ELF-MF exposure stabilizes active chromatin, particularly during the transition from a repressive to an active state during cell differentiation.

Pregnane X receptor-dependent induction of the CYP3A4 gene by o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane.

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Medina-Díaz, Irma M; Arteaga-Illán, Georgina; de León, Mario Bermudez; Cisneros, Bulmaro; Sierra-Santoyo, Adolfo; Vega, Libia; Gonzalez, Frank J; Elizondo, Guillermo

2007-01-01

CYP3A4, the predominant cytochrome P450 (P450) expressed in human liver and intestine, contributes to the metabolism of approximately half the drugs in clinical use today. CYP3A4 catalyzes the 6beta-hydroxylation of a number of steroid hormones and is involved in the bioactivation of environmental procarcinogens. The expression of CYP3A4 is affected by several stimuli, including environmental factors such as insecticides and pesticides. The o,p'-1,1,1,-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) isomer of DDT comprises approximately 20% of technical grade DDT, which is an organochloride pesticide. We have recently shown that o,p'-DDT exposure increases CYP3A4 mRNA levels in HepG2 cells. To determine the mechanism by which o,p'-DDT induces CYP3A4 expression, transactivation and electrophoretic mobility shift assays were carried out, revealing that o,p'-DDT activates the CYP3A4 gene promoter through the pregnane X receptor (PXR). CYP3A4 gene promoter activation resulted in both an increase in CYP3A4 mRNA levels and an increase in the total CYP3A4 activity in HepG2 cells. We also observed induction of CYP3A4 and mouse Cyp3a11 mRNA in the intestine of CYP3A4-transgenic mice after exposure to 1 mg/kg o,p'-DDT. At higher doses, a decrease of CYP3A4 inducibility was observed together with an increase in levels of interleukin 6 mRNA, a proinflammatory cytokine that strongly represses CYP3A4 transcription. The present study indicates that regulation of other genes under PXR control may be altered by o,p'-DDT exposure.

Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

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Federica Raggi

2017-09-01

Full Text Available Macrophages (Mf are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1 and alternatively activated (anti-inflammatory M2 subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment.

Regulation of Human Macrophage M1–M2 Polarization Balance by Hypoxia and the Triggering Receptor Expressed on Myeloid Cells-1

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Raggi, Federica; Pelassa, Simone; Pierobon, Daniele; Penco, Federica; Gattorno, Marco; Novelli, Francesco; Eva, Alessandra; Varesio, Luigi; Giovarelli, Mirella; Bosco, Maria Carla

2017-01-01

Macrophages (Mf) are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia. The impact of hypoxia on human Mf polarization has not been fully established. The objective of this study was to elucidate the effects of a hypoxic environment reflecting that occurring in vivo in diseased tissues on the ability of human Mf to polarize into classically activated (proinflammatory M1) and alternatively activated (anti-inflammatory M2) subsets. We present data showing that hypoxia hinders Mf polarization toward the M1 phenotype by decreasing the expression of T cell costimulatory molecules and chemokine homing receptors and the production of proinflammatory, Th1-priming cytokines typical of classical activation, while promoting their acquisition of phenotypic and secretory features of alternative activation. Furthermore, we identify the triggering receptor expressed on myeloid cells (TREM)-1, a member of the Ig-like immunoregulatory receptor family, as a hypoxia-inducible gene in Mf and demonstrate that its engagement by an agonist Ab reverses the M2-polarizing effect of hypoxia imparting a M1-skewed phenotype to Mf. Finally, we provide evidence that Mf infiltrating the inflamed hypoxic joints of children affected by oligoarticular juvenile idiopatic arthritis express high surface levels of TREM-1 associated with predominant M1 polarization and suggest the potential of this molecule in driving M1 proinflammatory reprogramming in the hypoxic synovial environment. PMID:28936211

DDT, DDD, AND DDE DECHLORINATION BY ZERO-VALENT IRON

Science.gov (United States)

Traditionally, destruction of DDT [1,1,1-trichIoro-2,2-bis(p-chlorophenyl)ethane] for environmental remediation required high-energy processes such as incineration. Here, the capability of powdered zero-valent iron to dechlorinate DDT and related compounds at room tempera...

The study of DDT in contaminated soil of abandoned DDT factory area of Amangarh Khyber Pakhtunkhwa

International Nuclear Information System (INIS)

Sanaullah, M.A.; Sabir, M.A.; Arfan, M.

2011-01-01

Dichlorodiphenyl trichloroethane (DDT) is an organo chlorine insecticide mainly used to control mosquito borne diseases and agricultural pests worldwide, including Pakistan. For DDT production a factory was established in 1963 in Amangargh, Nowshehra, KP. Although DDT production and its applications in agriculture have been banned since long and as a result the mentioned factory has also abandoned yet there remains extensive amount of DDT and contaminated sites are still releasing DDT to the environment. As a matter of fact even small amounts of DDT can affect a variety of organisms like small microorganisms, algae and plankton. DDT also causes many problems in fish, birds, mammals and somehow Human Beings. This research examined the soil's DDT concentration and its transformation at various depths of study site. The DDT from each soil sample was extracted using simply solvent extraction method. The residual DDT level found in almost all the soil samples taken was greater than the standard limit (< 17 mgKg/sup -1/). (author)

Screening and identification of p,p¢-DDT degrading soil isolates

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Vorasan Sobhon

2008-04-01

Full Text Available DDT is an organochlorine pesticide that can persist in the environment resulting in environmental problem with chronic effects on human and animal health. The determination of p,p¢-DDT in soil samples from 23 agricultural areas in Songkhla Province found DDT residue in the ranges of 0.17-9.84 ng/g soil. After repeated culturing in mineral salts-yeast extract medium (MSYM with an addition of 25 ppm p,p¢-DDT (DDT25, 167 morphologically different bacterial strains were isolated. Out of 167 isolates, only 5 strains showed p,p¢-DDT degrading ability as indicated by clear zone around the colony when grown on nutrient agar supplemented up to 100 ppm p,p¢-DDT. These 5 isolates include SB1A01, SB2A02, SB1A10, SB1A12 and SB1B05. Growth of these isolates in MSYM+DDT25 after 10 days indicated reductions of p,p¢-DDT by 30.5, 20.3, 37.4, 30.4 and 32.2%, respectively. Based on the morphological characteristics and 16S rDNA analysis, isolate SB1A10 which showed the highest degradation ability was found to be 99% identical (1360/1362 to Staphylococcus haemolyticus.

Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1

Energy Technology Data Exchange (ETDEWEB)

Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling; Gorman, Michael A.; Morton, Craig J.; Pyke, James; McConville, Malcolm J.; Bieri, Michael; Mok, Yee-Foong; Robin, Charles; Gooley, Paul R.; Parker, Michael W.; Batterham, Philip (SVIMR-A); (Melbourne)

2010-06-14

GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model of the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. We also show that the ancestral GSTD1 is likely to have possessed DDT dehydrochlorinase activity because both GSTD1 from D. melanogaster and its sibling species, Drosophila simulans, have this activity.

Ergonomic assessment of brake and accelerator mechanisms of MF285 and MF399 tractors using electromyography method

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A Nikkhah

2016-04-01

Full Text Available Introduction: Too many people are working in the agricultural sector and therefore, pay more attention to the safety and health at work in the agricultural sector is important. This issue is more important in developing industrial countries where the level of the ergonomic working condition is less than that of developed countries. Attention to ergonomic condition of agricultural machinery drivers is one of the goals of agricultural mechanization. Therefore, in this study the ergonomic conditions of brake and accelerator mechanisms for MF285 and MF399 tractor's drivers were investigated using a new method. Materials and Methods: 25 people were selected for experiment. The electrical activity of Medialis gastrocnemius, Lateralis gastrocnemius, Vastus medialis, Vastus lateralis, Quadratus Lumborum and Trapezius muscles of drivers before and during pressing the pedal and after rest time were recorded using Biovision device. Measurements were performed for each person on each muscle 30 seconds before pressing the pedal, 60 seconds after pressing the pedal and after 60 seconds of rest. For all drivers, the muscles on the right side (brake and accelerator side have been selected and tested. The measurements were performed in compliance with appropriate time intervals between the measurements. Results and Discussion: Ergonomic assessment of brake pedal: The results showed that the RMS electrical activity of muscles of Vastus medialis and Medial gastrocnemius, during 60 seconds braking were 2.47 and 1.97. So, Vastus medialis and Medial gastrocnemius had the highest stress during pressing the MF399 tractor's brake pedal. Moreover, the Medial gastrocnemius and Lateral gastrocnemius with RMS electrical activity ratio of 2.47 and 1.74 had the highest RMS electrical activity ratio respectively, during 60 seconds braking compared to before braking of MF285 tractor. The comparison of results showed that the Vastus medialis and Trapezius had the higher stress

DIKLORO DIFENIL TRIKOLOETAN (DDT

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Siti Alfiah

2013-12-01

Full Text Available ABSTRACT Invention of Dikloro Difenil Trikoloetan (DDT by Zeidler in 1874 was first began of syntetic insectiside discovery. DDT was classified in chlorinated hydrocarbons. Persistance of DDTin organism and environment have been forbidden to use in  many countries in the world. The resistance of DDT to mosquitoes and flies was reported in 1948. It was caused of change of metabolism, target site insensitivity, phisiology and behaviour mechanism. The problems of DDT could be solved by insecticide substitution which had different method, such as organophosphate and carbamate. Keywords : DDT, insecticide, organochlorine, resistance ABSTRAK Penemuan Dikloro Difenil Trikoloetan (DDT oleh Zeidler pada tahun 1874 mengawali penemuan insektisida sintetik. DDT tergolong dalam hidrokarbon berklor (chlorinated hydrocarbonsatau organochlorines. DDT tidak mudah terurai dan persisten di organisme maupun lingkungan, akibatnya banyak negara di berbagai belahan dunia melarang penggunaan DDT. Pada tahun 1948 sudah mulai dilaporkan terjadinya resistensi DDT pada nyamuk dan lalat. Resistensi serangga terhadap DDT dikarenakan metabolisme yang berubah, target site insensitivity (resistensi karena gen knock-down resistance, mekanisme fisiologis dan perilaku. Masalah yang timbul akibat DDT dapatditangani dengan penggantian insektisida. DDT diganti dengan insektisida yang cara kerjanya berbeda dalam membunuh serangga (resistensi silang negatif, yaitu insektisida golonganorganofosfat atau karbamat. Kata kunci : DDT, insektisida, organokhlorin, resistensi

40 CFR 721.2287 - DDT (Dichlorodiphenyltrichloroethane).

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2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false DDT (Dichlorodiphenyltrichloroethane... Substances § 721.2287 DDT (Dichlorodiphenyltrichloroethane). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance DDT (dichlorodiphenyltrichloroethane) (CAS No. 50-29-3...

Evaluation of the Synergistic Effect of Mixed Cultures of White-Rot Fungus Pleurotus ostreatus and Biosurfactant-Producing Bacteria on DDT Biodegradation.

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Purnomo, Adi Setyo; Ashari, Khoirul; Hermansyah, Farizha Triyogi

2017-07-28

DDT (1,1,1-trichloro-2,2- bis (4-chlorophenyl) ethane) is one of the organic synthetic pesticides that has many negative effects for human health and the environment. The purpose of this study was to investigate the synergistic effect of mixed cutures of white-rot fungus, Pleurotus ostreatus , and biosurfactant-producing bacteria, Pseudomonas aeruginosa and Bacillus subtilis , on DDT biodegradation. Bacteria were added into the P. ostreatus culture (mycelial wet weight on average by 8.53 g) in concentrations of 1, 3, 5, and 10 ml (1 ml ≈ 1.25 × 10 9 bacteria cells/ml culture). DDT was degraded to approximately 19% by P. ostreatus during the 7-day incubation period. The principal result of this study was that the addition of 3 ml of P. aeruginosa into P. ostreatus culture gave the highest DDT degradation rate (approximately 86%) during the 7-day incubation period. This mixed culture combination of the fungus and bacteria also gave the best ratio of optimization of 1.91. DDD (1,1-dichloro-2,2- bis (4-chlorophenyl) ethane), DDE (1,1-dichloro-2,2- bis (4-chlorophenyl) ethylene), and DDMU (1-chloro-2,2- bis (4-chlorophenyl) ethylene) were detected as metabolic products from the DDT degradation by P. ostreatus and P. aeruginosa . The results of this study indicate that P. aeruginosa has a synergistic relationship with P. ostreatus and can be used to optimize the degradation of DDT by P. ostreatus .

The Environmental Issues of DDT Pollution and Bioremediation: a Multidisciplinary Review.

Science.gov (United States)

Mansouri, Ahlem; Cregut, Mickael; Abbes, Chiraz; Durand, Marie-Jose; Landoulsi, Ahmed; Thouand, Gerald

2017-01-01

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is probably the best known and most useful organochlorine insecticide in the world which was used since 1945 for agricultural purposes and also for vector-borne disease control such as malaria since 1955, until its banishment in most countries by the Stockholm convention for ecologic considerations. However, the World Health Organization allowed its reintroduction only for control of vector-borne diseases in some tropical countries in 2006. Due to its physicochemical properties and specially its persistence related with a half-life up to 30 years, DDT linked to several health and social problems which are due to its accumulation in the environment and its biomagnification properties in living organisms. This manuscript compiles a multidisciplinary review to evaluate primarily (i) the worldwide contamination of DDT and (ii) its (eco) toxicological impact onto living organisms. Secondly, several ways for DDT bioremediation from contaminated environment are discussed. For this, reports on DDT biodegradation capabilities by microorganisms and ways to enhance bioremediation strategies to remove DDT are presented. The different existing strategies for DDT bioremediation are evaluated with their efficiencies and limitations to struggle efficiently this contaminant. Finally, rising new approaches and technological bottlenecks to promote DDT bioremediation are discussed.

Model ecosystem determination of the metabolic and environmental fate of tetrachloro-DDT

International Nuclear Information System (INIS)

Cole, R.B.; Metcalf, R.L.

1987-01-01

A potential hazardous waste site investigation was conducted by the Environmental Protection Agency to determine whether ground water, surface water, or area soils and sediments were contaminated as a result of waster water discharges or improper solid waste disposal practices of a pesticide manufacturer. One of the compounds discharged into the environment was 1,1,1,2-tetrachloro-2,2-bis(p-chlorophenyl)ethane, commonly referred to as tetrachloro-DDT. Unlike a great many of the DDT analogs, tetrachloro-DDT has come under only limited scrutiny, mainly because it was dismissed as having poor insecticidal properties relative to DDT and other analogs. Its metabolism in ingesting organisms, and degradative pathways in the environment have consequently been left uncertain. This model ecosystem study was undertaken to examine the unanswered questions concerning the metabolic and environmental fate of tetrachloro-DDT. The relevance of this study pertains to disposal practices of pesticide manufacturers who use tetrachloro-DDT as a product precursor

Percutaneous absorption of [14C]DDT and [14C]benzo[a]pyrene from soil

International Nuclear Information System (INIS)

Wester, R.C.; Maibach, H.I.; Bucks, D.A.; Sedik, L.; Melendres, J.; Liao, C.; DiZio, S.

1990-01-01

The objective was to determine percutaneous absorption of DDT and benzo[a]pyrene in vitro and in vivo from soil into and through skin. Soil (Yolo County 65-California-57-8; 26% sand, 26% clay, 48% silt) was passed through 10-, 20-, and 48-mesh sieves. Soil then retained by 80-mesh was mixed with [14C]-labeled chemical at 10 ppm. Acetone solutions at 10 ppm were prepared for comparative analysis. Human cadaver skin was dermatomed to 500 microns and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 24-hr skin application time. With acetone vehicle, DDT (18.1 +/- 13.4%) readily penetrated into human skin. Significantly less DDT (1.0 +/- 0.7%) penetrated into human skin from soil. DDT would not partition from human skin into human plasma in the receptor phase (less than 0.1%). With acetone vehicle, benzo[a]pyrene (23.7 +/- 9.7%) readily penetrated into human skin. Significantly less benzo[a]pyrene (1.4 +/- 0.9%) penetrated into human skin from soil. Benzo[a]pyrene would not partition from human skin into human plasma in the receptor phase (less than 0.1%). Substantivity (skin retention) was investigated by applying 14C-labeled chemical to human skin in vitro for only 25 min. After soap and water wash, 16.7 +/- 13.2% of DDT applied in acetone remained absorbed to skin. With soil only 0.25 +/- 0.11% of DDT remained absorbed to skin. After soap and water wash 5.1 +/- 2.1% of benzo[a]pyrene applied in acetone remained absorbed to skin. With soil only 0.14 +/- 0.13% of benzo[a]pyrene remained absorbed to skin

Involvement of oxidative stress in the mechanism of p,p'-DDT-induced nephrotoxicity in adult rats.

Science.gov (United States)

Marouani, Neila; Hallegue, Dorsaf; Sakly, Mohsen; Benkhalifa, Moncef; Ben Rhouma, Khémais; Tebourbi, Olfa

2017-07-01

The 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (p,p'-DDT) is an organochlorine pesticide that persists in the environment and has a risk to human health. We investigated whether p,p'-DDT-induces nephrotoxicity in rats and whether oxidative stress and apoptosis are involved in the pathogenesis of this process. Male rats received the pesticide at doses of 50 and 100 mg/kg for 10 days. Renal damage was evaluated by histopathological examination and serum markers. The oxidative stress was evaluated by lipid peroxidation (LPO), metallothioneins (MTs) and protein carbonyl levels. Antioxidant enzymes were assessed by determination of superoxide dismutase (SOD) and catalase (CAT) activities. Glutathione-dependent enzymes and reducing power in kidney were evaluated by glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST) activities. Renal tubular cells apoptosis was assessed through the TUNEL assay. After 10 days of treatment, an increase of serum creatinine and urea levels occurred, LPO and protein carbonyl levels were increased, while MTs level, SOD and CAT activities were decreased. Besides, the GPx, GR, GST, and GSH activities were decreased. Histological alterations in kidney tissue and intense apoptosis in renal tubular cells were observed. These results suggest that DDT sub-acute treatment causes oxidative stress and apoptosis, which may be the chief mechanisms of DDT-induced nephrotoxicity.

DDT increases hepatic testosterone metabolism in rats

Energy Technology Data Exchange (ETDEWEB)

Sierra-Santoyo, Adolfo; Albores, Arnulfo; Cebrian, Mariano E. [Cinvestav-IPN, Seccion de Toxicologia, Mexico (Mexico); Hernandez, Manuel [Cinvestav-IPN, Departamento de Biologia Celular (Mexico)

2005-01-01

DDT and its metabolites are considered as endocrine disruptors able to promote hormone-dependent pathologies. We studied the effects of technical-grade DDT on hepatic testosterone metabolism and testosterone hydroxylase activity ratios in the rat. Male and female Wistar rats were treated by gavage with a single dose of technical-grade DDT (0, 0.1, 1, 10, and 100 mg/kg body weight) and killed 24 h later. Hepatic microsomes were incubated with [4-{sup 14}C]-testosterone and the metabolites were separated by thin-layer chromatography and quantified by radio scanning. DDT increased testosterone biotransformation and modified the profile of metabolites produced in a sex-dependent manner. Males treated with a representative dose (10 mg/kg) produced relatively less androstenedione (AD), 2{alpha}-hydroxytestosterone (OHT), and 16{alpha}-OHT but higher 6{beta}-OHT whereas treated females produced less 7{alpha}-OHT and AD but higher 6{beta}-OHT and 6{alpha}-OHT than their respective controls. In both sexes DDT decreased the relative proportion of AD and increased that of 6{beta}-OHT suggesting that the androgen-saving pathway was affected. The testosterone 6{alpha}-/15{alpha}-OHT ratio, a proposed indicator of demasculinization, was increased in treated males. This effect was in agreement with the demasculinizing ability proposed for DDT. The effects on 6{alpha}-/16{alpha}-OHT and 6-dehydrotestosterone/16{alpha}-OHT ratios followed a similar tendency, with the ratio 6{alpha}-/16{alpha}-OHT being the most sensitive marker. Interestingly, these ratios were reduced in treated females suggesting that technical-grade DDT shifted testosterone hydroxylations toward a more masculine pattern. Thus, technical-grade DDT altered the hepatic sexual dimorphism in testosterone metabolism and decreased the metabolic differences between male and female rats. (orig.)

textbf{Historical Usage Inventories of DDT in China}

Science.gov (United States)

Qiang, Wang; Lijuan, Zhao; Jianxin, Hu

2010-05-01

from dicofol use and 766 tons applied for malaria control, and the annual average usage of DDT was 766 tons. Spatial distribution of DDT usage has direct relationship with sown areas of cotton, apple, citrus, tea and vegetable, and the DDT usage is concentrated in middle and east China where there is large sown area of cotton and apple, the historical use trend is affected by the weather and acarid harm. On province scale in China, Shandong province was the largest consumer of DDT, whose usage added up to 2,094 tons. On prefecture scale, Xianyang city was the largest consumer of DDT, adding up to 304 tons. Shandong province used the most of DDT resulting from dicofol among the provinces/regions, adding up to 1,866 tons; and Yunnan Province used the most of DDT applied for malaria control among the prefectures, adding up to 481 tons.

The Validation Of Influence Factors To DDT Concentration In Soil; Validasi Faktor-Faktor Yang Berpengaruh Terhadap Kadar DDT Di Dalam Tanah

Energy Technology Data Exchange (ETDEWEB)

Kamal, Zainul; Poernomo, Herry [Center for Research and Development of Advanced Technology, National Nuclear Energy Agency, Serpong (Indonesia)

2000-09-01

Determination concentration of DDT in humidified land's and rising intensity has been done. The amount of natural soil was filled in poliethylene tube, and the amount of humadified soil was filled in order poliethylene tube. The solution of DDT-C sub.14 with volume of 10 ml and activity of 10 muCi was increased in those tube respectively, the latter it was resident for many time under shine. Sample of soil was took first week to sixthweek, it was crushed to reach homogenous, then it was counted by liquid scintillation counter. The experiment result indicated that the DDT content in the unilluminated soil for 1 week is < 0.1 ppb, for 2 week is 0.19 n 0.01 ppb, for 3 week is 1.95 n 0.32 ppb, for 4 week is 14.07 n 0.14 ppb, for 5 week is 3.67 n 0.21 ppb and for 6 week is 2.28 n 0.09 ppb. The DDT content in the humidified soil without sun illumination for 1 week is 0.25 n 0.07 ppb, for 2 week is 6.34 n 0.19 ppb, for 3 week is 9.33 n 0.80 ppb, for 4 week is 12.36 n 0.17 ppb, for 5 week is 4.58 n 0.15 ppb and for 6 week is 2.01 n 0.55 ppb. The DDT content in the natural soil illuminated by VIS for 1 week is 0.74 n 0.08 ppb, for 2 week is 7.48 n 0.14 ppb, for 3 week is 4.06 n 0.28 ppb, for 4 week is 13.16 n 0.20 ppb, for 5 week is 5.00 n 0.70 ppb and for 6 week is 2.03 n 0.03 ppb.

Anaerobic transformation of DDT related to iron(III) reduction and microbial community structure in paddy soils.

Science.gov (United States)

Chen, Manjia; Cao, Fang; Li, Fangbai; Liu, Chengshuai; Tong, Hui; Wu, Weijian; Hu, Min

2013-03-06

We studied the mechanisms of microbial transformation in functional bacteria on 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in two different field soils, Haiyan (HY) and Chenghai (CH). The results showed that microbial activities had a steady dechlorination effect on DDT and its metabolites (DDx). Adding lactate or glucose as carbon sources increased the amount of Desulfuromonas, Sedimentibacter, and Clostridium bacteria, which led to an increase in adsorbed Fe(II) and resulted in increased DDT transformation rates. The electron shuttle of anthraquinone-2,6-disulfonic disodium salt resulted in an increase in the negative potential of soil by mediating the electron transfer from the bacteria to the DDT. Moreover, the DDT-degrading bacteria in the CH soil were more abundant than those in the HY soil, which led to higher DDT transformation rates in the CH soil. The most stable compound of DDx was 1,1-dichloro-2,2-bis(p-chloro-phenyl)ethane, which also was the major dechlorination metabolite of DDT, and 1-chloro-2,2-bis-(p-chlorophenyl)ethane and 4,4'-dichlorobenzo-phenone were found to be the terminal metabolites in the anaerobic soils.

Elucidating Turnover Pathways of Bioactive Small Molecules by Isotopomer Analysis: The Persistent Organic Pollutant DDT

Science.gov (United States)

Ehlers, Ina; Betson, Tatiana R.; Vetter, Walter; Schleucher, Jürgen

2014-01-01

The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment. To differentiate between DDD formation pathways, we applied deuterium NMR spectroscopy to measure intramolecular deuterium distributions (2H isotopomer abundances) of DDT and DDD. DDD formed in the technical DDT synthesis was strongly deuterium-enriched at one intramolecular position, which we traced back to 2H/1H fractionation of a chlorination step in the technical synthesis. In contrast, DDD formed by reductive degradation was strongly depleted at the same position, which was due to the incorporation of 2H-depleted hydride equivalents during reductive degradation. Thus, intramolecular isotope distributions give mechanistic information on reaction pathways, and explain a puzzling difference in the whole-molecule 2H/1H ratio between DDT and DDD. In general, our results highlight that intramolecular isotope distributions are essential to interpret whole-molecule isotope ratios. Intramolecular isotope information allows distinguishing pathways of DDD formation, which is important to identify polluters or to assess DDT turnover in the environment. Because intramolecular isotope data directly reflect isotope fractionation of individual chemical reactions, they are broadly applicable to elucidate transformation pathways of small bioactive molecules in chemistry, physiology and environmental science. PMID:25350380

Male fertility following occupational exposure to dichlorodiphenyltrichloroethane (DDT).

Science.gov (United States)

Campagna, Marcello; Satta, Giannina; Fadda, Domenica; Pili, Sergio; Cocco, Pierluigi

2015-04-01

The inconsistent epidemiological results of the endocrine disrupting effects of DDT fuel a harsh debate on its global ban. We tested the hypothesis that occupational exposure to dichloro-diphenyl-trichloroethane (DDT) causes impairment in male fertility in a cohort of DDT exposed workers, in Sardinia, Italy. We accessed official records on date of marriage and date of birth of the first child to estimate time to pregnancy (TTP) in the spouses of 1223 workers employed in a 1946-1950 anti-malarial campaign. The TTP calculation was censored at the 13th month after date of marriage. We used a modified Cox's proportional hazard model to calculate the fecundability ratio (FR) by job, by cumulative exposure to DDT, and by time window in relation to the anti-malarial operations, adjusting by paternal age at marriage. Among the spouses of DDT applicators, fecundability did not vary during DDT use (FR=1.22, 95% CI 0.84-1.77) nor in the following decade (FR=1.01, 95% CI 0.67-1.50) with reference to the prior years. A significant increase occurred among the unexposed and the less exposed sub-cohorts, which generated a non-significantly reduced FR among the DDT applicator sub-cohort with reference to the unexposed following exposure. We did not find evidence of an impairment in male fertility following heavy occupational exposure to DDT. However, although fecundability was highest among the spouses of the DDT applicators in the years prior to the anti-malarial campaign, we cannot exclude that DDT exposure prevented an increase parallel to that observed among the unexposed and the less exposed sub-cohorts. Copyright © 2015. Published by Elsevier Ltd.

Effects of microbial inhibitors on anaerobic degradation of DDT

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.S.; Chiu, T.C.; Yen, J.H. [National Taiwan Univ., Taipei (Taiwan)

2004-09-15

Chlorinated insecticide DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] was extensively used for controlling pests in the agricultural field and human-being living environments in the past several decades. Due to the chemical stability, DDT was extremely persistent and recalcitrant in soils and sediments and it was banned by nations. Microorganisms usually play important roles in reducing organochlorine compounds in the environments. Under low-oxygen conditions, microbial dechlorination is thought as the onset of highly chlorinated compounds. Methanogenic and sulfate-reducing bacteria participate in microbial dechlorination under anaerobic condition has been reported. In this study, a mixed anaerobic culture enabling to dechlorinate DDT was obtained from river sediment in Taiwan. In order to understand the effect of these microorganisms on DDT dechlorination, microbial inhibitors BESA (2-bromoethanesulfonate) and molybdate, for inhibiting methanogenic and sulfate-reducing bacteria, respectively, were chosen to investigate the interaction between specific microbial communities and their degradation activities. Besides, a molecular technique, denaturing gradient gel electrophoresis (DGGE), based on analyzing the 16S rDNA of bacteria, was used for monitoring the bacterial community structure in this study.

ANAEROBIC DDT BIOTRANSFORMATION: ENHANCEMENT BY APPLICATION OF SURFACTANTS AND LOW OXIDATION REDUCTION POTENTIAL

Science.gov (United States)

Enhancement of anaerobic DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane) biotransformation by mixed cultures was studied with application of surfactants and oxidation reduction potential reducing agents. Without amendments, DDT transformation resulted mainly in the pr...

Low dose DDT inhibition of hepatocarcinogenesis initiated by diethylnitrosamine in male rats: Possible mechanisms

International Nuclear Information System (INIS)

Kushida, Masahiko; Sukata, Tokuo; Uwagawa, Satoshi; Ozaki, Keisuke; Kinoshita, Anna; Wanibuchi, Hideki; Morimura, Keiichirou; Okuno, Yasuyoshi; Fukushima, Shoji

2005-01-01

Previously we reported a tendency for reduction of the development of glutathione-S-transferase placental form (GST-P) positive foci, recognized as preneoplastic changes in rat liver, by a low dose of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), which belongs to the same group of hepatic cytochrome P-450 inducers as phenobarbital and is itself a non-genotoxic hepatocarcinogen. In order to clarify the biological significance of this phenomenon, we investigated the reproducibility and changes in other parameters using an initiation-promotion model in which male F344 rats were treated with DDT at doses of 0, 0.005, 0.5, 500 ppm in the diet for 11 or 43 weeks after initiation of hepatocarcinogenesis with N-diethylnitrosamine (DEN). When 500 ppm DDT was applied, the formation of GST-P positive foci and tumor were markedly elevated. In contrast, induction of GST-P positive foci and liver tumors tended to be inhibited at a dose of 0.005 ppm, correlating with protein levels of cytochrome P450 2B1 and 3A2 (CYP2B1 and 3A2) and generation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. mRNA levels for 8-oxoguanine glycosylase 1 (OGG1), an 8-OHdG repair enzyme, connexin 32 (Cx32), a major component of Gap junctions, and hepatic nuclear factor 1α (HNF-1α), a Cx32 regulator, were inversely correlated with GST-P positive foci and tumor formation. These results indicate that low dose DDT may indeed exhibit inhibitory effects on chemically initiated-rat hepatocarcinogenicity, in contrast to the promotion observed with high doses, and that this is related to changes in metabolizing enzymes, cell communication, and DNA damage and its repair

The interactive biotic and abiotic processes of DDT transformation under dissimilatory iron-reducing conditions.

Science.gov (United States)

Jin, Xin; Wang, Fang; Gu, Chenggang; Yang, Xinglun; Kengara, Fredrick O; Bian, Yongrong; Song, Yang; Jiang, Xin

2015-11-01

The objective of the study was to elucidate the biotic and abiotic processes under dissimilatory iron reducing conditions involved in reductive dechlorination and iron reduction. DDT transformation was investigated in cultures of Shewanella putrefaciens 200 with/without α-FeOOH. A modified first-order kinetics model was developed and described DDT transformation well. Both the α-FeOOH reduction rate and the dechlorination rate of DDT were positively correlated to the biomass. Addition of α-FeOOH enhanced reductive dechlorination of DDT by favoring the cell survival and generating Fe(II) which was absorbed on the surface of bacteria and iron oxide. 92% of the absorbed Fe(II) was Na-acetate (1M) extractable. However, α-FeOOH also played a negative role of competing for electrons as reflected by the dechlorination rate of DDT was inhibited when increasing the α-FeOOH from 1 g L(-1) to 5 g L(-1). DDT was measured to be toxic to S. putrefaciens 200. The metabolites DDD, DDE and DDMU were recalcitrant to S. putrefaciens 200. The results suggested that iron oxide was not the key factor to promote the dissipation of DDX (DDT and the metabolites), whereas the one-electron reduction potential (E1) of certain organochlorines is the main factor and that the E1 higher than the threshold of the reductive driving forces of DIRB probably ensures the occur of reductive dechlorination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Overexpression of MfPIP2-7 from Medicago falcata promotes cold tolerance and growth under NO3 (-) deficiency in transgenic tobacco plants.

Science.gov (United States)

Zhuo, Chunliu; Wang, Ting; Guo, Zhenfei; Lu, Shaoyun

2016-06-14

Plasma membrane intrinsic proteins (PIPs), which belong to aquaporins (AQPs) superfamily, are subdivided into two groups, PIP1 and PIP2, based on sequence similarity. Several PIP2s function as water channels, while PIP1s have low or no water channel activity, but have a role in water permeability through interacting with PIP2. A cold responsive PIP2 named as MfPIP2-7 was isolated from Medicago falcata (hereafter falcata), a forage legume with great cold tolerance, and transgenic tobacco plants overexpressing MfPIP2-7 were analyzed in tolerance to multiple stresses including freezing, chilling, and nitrate reduction in this study. MfPIP2-7 transcript was induced by 4 to 12 h of cold treatment and 2 h of abscisic acid (ABA) treatment. Pretreatment with inhibitor of ABA synthesis blocked the cold induced MfPIP2-7 transcript, indicating that ABA was involved in cold induced transcription of MfPIP2-7 in falcata. Overexpression of MfPIP2-7 resulted in enhanced tolerance to freezing, chilling and NO3 (-) deficiency in transgenic tobacco (Nicotiana tabacum L.) plants as compared with the wild type. Moreover, MfPIP2-7 was demonstrated to facilitate H2O2 diffusion in yeast. Higher transcript levels of several stress responsive genes, such as NtERD10B, NtERD10C, NtDREB1, and 2, and nitrate reductase (NR) encoding genes (NtNIA1, and NtNIA2) were observed in transgenic plants as compared with the wild type with dependence upon H2O2. In addition, NR activity was increased in transgenic plants, which led to alterations in free amino acid components and concentrations. The results suggest that MfPIP2-7 plays an important role in plant tolerance to freezing, chilling, and NO3 (-) deficiency by promoted H2O2 diffusion that in turn up-regulates expression of NIAs and multiple stress responsive genes.

Dichlorodiphenyltrichloroethane (DDT) and risk of hepatocellular carcinoma

Science.gov (United States)

Persson, E. Christina; Graubard, Barry I.; Evans, Alison A.; London, W. Thomas; Weber, Jean-Philippe; LeBlanc, Alain; Chen, Gang; Lin, Wenyao; McGlynn, Katherine A.

2014-01-01

Dichlorodiphenyltrichloroethane (p,p’-DDT), an organochlorine pesticide known to have deleterious health effects in humans, has been linked to hepatocellular carcinoma (HCC) in rodents. A recent study has reported that p,p’-DDT and its most persistent metabolite, dichlorodiphenyldichloroethylene (p,p’-DDE), may also be associated with HCC in humans. To examine whether there is an association between p,p’-DDT and/or p,p’-DDE in a population at high-risk of developing HCC. A nested case-control study was conducted within the 83,794 person Haimen City Cohort in China. Sera and questionnaire data were collected from all participants between 1992 and 1993. The current study included 473 persons who developed HCC and 492 who did not, frequency matched on sex, age and area of residence. p,p’-DDT and p,p’-DDE levels were determined by mass spectrometry. Hepatitis B viral infection status (based on hepatitis B virus surface antigen; HBsAg) was also determined. Adjusting for age, sex, area of residence, HBsAg, family history of HCC, history of acute hepatitis, smoking, alcohol, occupation (farmers) and levels of p,p’-DDT or p,p’-DDE, odds ratios (OR) and 95% confidence intervals (CI) were calculated via unconditional logistic regression, p,p’-DDT and/or p,p’-DDE serum levels were significantly associated with sex, area of residence, occupation, alcohol consumption and cigarette smoking. Overall, the highest quintile of p,p’-DDT was associated with an increased risk of HCC, OR= 2.96 95% CI; 1.19–7.40. There were no statistically significant associations with p,p’-DDE. Overall, these results suggest that recent exposure to p,p’-DDT may increase risk of HCC. PMID:22290210

Studies on solubility, glass-adsorption, extraction and evaporation of DDT using 36Cl-DDT

International Nuclear Information System (INIS)

Duursma, E.K.; Vas, D.; Marchand, M.

1974-01-01

A series of experiments are reported to investigate the behaviour of DDT in seawater using 36 Cl-DDT to determine DDT solubility in seawater, its adsorption to walls of glass vessels, the reproductibility of DDT extraction from seawater by organic solvents and its volatility when brought to dryness from solution

DDT-based indoor residual spraying suboptimal for visceral leishmaniasis elimination in India.

Science.gov (United States)

Coleman, Michael; Foster, Geraldine M; Deb, Rinki; Pratap Singh, Rudra; Ismail, Hanafy M; Shivam, Pushkar; Ghosh, Ayan Kumar; Dunkley, Sophie; Kumar, Vijay; Coleman, Marlize; Hemingway, Janet; Paine, Mark J I; Das, Pradeep

2015-07-14

Indoor residual spraying (IRS) is used to control visceral leishmaniasis (VL) in India, but it is poorly quality assured. Quality assurance was performed in eight VL endemic districts in Bihar State, India, in 2014. Residual dichlorodiphenyltrichloroethane (DDT) was sampled from walls using Bostik tape discs, and DDT concentrations [grams of active ingredient per square meter (g ai/m(2))] were determined using HPLC. Pre-IRS surveys were performed in three districts, and post-IRS surveys were performed in eight districts. A 20% threshold above and below the target spray of 1.0 g ai/m(2) was defined as "in range." The entomological assessments were made in four districts in IRS and non-IRS villages. Vector densities were measured: pre-IRS and 1 and 3 mo post-IRS. Insecticide susceptibility to 4% DDT and 0.05% deltamethrin WHO-impregnated papers was determined with wild-caught sand flies. The majority (329 of 360, 91.3%) of pre-IRS samples had residual DDT concentrations of DDT post-IRS was 0.37 g ai/m(2); 84.9% of walls were undersprayed, 7.4% were sprayed in range, and 7.6% were oversprayed. The abundance of sand flies in IRS and non-IRS villages was significantly different at 1 mo post-IRS only. Sand flies were highly resistant to DDT but susceptible to deltamethrin. The Stockholm Convention, ratified by India in 2006, calls for the complete phasing out of DDT as soon as practical, with limited use in the interim where no viable IRS alternatives exist. Given the poor quality of the DDT-based IRS, ready availability of pyrethroids, and susceptibility profile of Indian sand flies, the continued use of DDT in this IRS program is questionable.

Bioremediation of a pesticide polluted soil: Case DDT

International Nuclear Information System (INIS)

Betancur Corredor, Bibiana; Pino, Nancy; Penuela, Gustavo A; Cardona Gallo, Santiago

2013-01-01

1,1,1-trichloro-2,2 bis (p-chlorophenyl) ethane (DDT) has been used since the Second World War to control insect-borne diseases in humans and domestic animals. The use of these organochlorine insecticides has been banned in most countries because of its persistence in the environment, biomagnification and potential susceptibility to toxicity to higher animals. Bioremediation involves the use of microorganisms to degrade organic contaminants in the environment, transforming them into simpler and less dangerous, even harmless compounds. This decontamination strategy has low costs, and wide public acceptance, also it can take place on the site. Compared to other methods, bioremediation is a more promising and less expensive to eliminate contaminants in soil and water. In soil, compounds such as DDT, chlorinated biphenyls can be partially biodegraded by a group of aerobic bacteria that cometabolize the contaminant. The bioavailability of pollutants may be enhanced by treating the soil in the presence of contaminant mobilizing agents such as surfactants. In this review we discuss the different strategies for bioremediation of soil contaminated with DDT, including mechanisms and degradation pathways. The application of these techniques in contaminated soil is also described. This review also discusses which is the best strategy for bioremediation of DDT.

Serotonergic changes following proestrous treatment with p,p'-DDT

International Nuclear Information System (INIS)

Uphouse, L.; Eckols, K.; Croissant, D.; Stewart, G.

1990-01-01

The effects of 25 and 75 mg/kg p,p'-DDT on the CNS serotonergic system were examined in proestrous female rats. Females were treated with p,p'-DDT on the morning of proestrus and were sacrificed that evening. Levels of serotonin (5-HT) and its major metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were examined in cortex, hippocampus, hypothalamus and preoptic areas. The binding of 3'-8-OH-DPAT [2-hydroxy-2-N, N-(di-propylamino)-tetralin], an agonist for 5-HT1A receptors, was examined in hippocampus and frontal cortex. P,p'-DDT decreased the level of 5-HT in frontal cortex and hippocampus. Elevations in 5-HIAA were present in the hypothalamus but only at the higher dose of p,p'-DDT. The dose of 25 mg/kg p,p'-DDT produced an increase in the Bmax for 3H-8-OH-DPAT binding to frontal cortical and hippocampal membranes. Membrane preparations from females given 75 mg/kg p,p'-DDT fell into two categories. Some were similar to the control but with a slightly higher Kd; others could not be analyzed by traditional linear or nonlinear regression procedures because they showed a constant proportion of bound label, independent of the concentration of 3H-ligand in the reaction. In vitro, p,p'-DDT did not compete with 3H-8-OH-DPAT for binding to cortical membranes so it is unlikely that residual pesticide in the membrane preparation accounted for the binding results. These binding results are particularly interesting because, in previous studies, the dose of 25 mg/kg p,p'-DDT was shown to be more potent than 75 mg/kg p,p'-DDT in reducing female rodent lordosis behavior

Photocatalytic degradation of p,p'-DDT under UV and visible light using interstitial N-doped TiO₂.

Science.gov (United States)

Ananpattarachai, Jirapat; Kajitvichyanukul, Puangrat

2015-01-01

1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (or p,p'-DDT) is one of the most persistent pesticides. It is resistant to breakdown in nature and cause the water contamination problem. In this work, a major objective was to demonstrate the application of N-doped TiO2 in degradation and mineralization of the p,p'-DDT under UV and visible light in aqueous solution. The N-doped TiO2 nanopowders were prepared by a simple modified sol-gel procedure using diethanolamine (DEA) as a nitrogen source. The catalyst characteristics were investigated using XRD, SEM, TEM, and XPS. The adsorption and photocatalytic oxidation of p,p'-DDT using the synthesized N-doped TiO2 under UV and visible light were conducted in a batch photocatalytic experiment. The kinetics and p,p'-DDT degradation performance of the N-doped TiO2 were evaluated. Results show that the N-doped TiO2 can degrade p,p'-DDT effectively under both UV and visible lights. The rate constant of the p,p'-DDT degradation under UV light was only 0.0121 min(-1), whereas the rate constant of the p,p'-DDT degradation under visible light was 0.1282 min(-1). Under visible light, the 100% degradation of p,p'-DDT were obtained from N-doped TiO2 catalyst. The reaction rate of p,p'-DDT degradation using N-doped TiO2 under visible light was sixfold higher than that under UV light. According to Langmuir-Hinshelwood model, the adsorption equilibrium constant (K) for the N-doped TiO2 under visible light was 0.03078 L mg(-1), and the apparent reaction rate constant (k) was 1.3941 mg L(-1)-min. Major intermediates detected during the p,p'-DDT degradation were p,p'-DDE, o,p'-DDE, p,p'-DDD and p,p'-DDD. Results from this work can be applied further for the breakdown of p,p'-DDT molecule in the real contaminated water using this technology.

Determination of DDT and metabolites in surface water and sediment using LLE, SPE, ACE and SE.

Science.gov (United States)

Sibali, Linda L; Okonkwo, Jonathan O; Zvinowanda, Caliphs

2009-12-01

Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,4'DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 μg/L, nd-0.80 μg/L, nd-1.21 μg/L and 1.92 μg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,4' and 4,4'-DDT) in water and sediment samples ranged from 1.20-3.25 μg/L and 1.82-5.24 μg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

Science.gov (United States)

2013-01-01

Background Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease. Methods Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm. Results The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity. Conclusions Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance. PMID:24228800

Enzyme immunoassay for DDT analysis in Lebanese soils

International Nuclear Information System (INIS)

Bashour, I.; Dagher, S.; Shammas, G.; Sukkariyah, B.; Kawar, N.

2000-01-01

Full text: The use of enzyme-linked immunosorbent assay (ELISA) technique in estimating pesticide residue in soils is a faster, less expensive and easier method to use than the gas chromatography (GC) analysis technique..In the test, DDT pesticide residues in the simple compete with enzyme (horseradish peroxidase)-labeled DDT for a limited number of antibody binding sites on the inside surfaces of the test wells; the envirologix plate kit was tested for the measurement of total DDT in virgin and fortified (0-1000 ng g exp-1) soil samples of different properties from Lebanon. Extraction of DDT from soil was done by shaking the samples for 16 hours on a mechanical shaker with 90% methanol without any clean-up steps. Then the samples were allowed to stand for 30 minutes and an aliquot was taken from the clear supernatant. The DDT in the extract was measured in triplicate by GC and ELISA. The results indicated that the two techniques were highly correlated (r2 =0.9671-0.9973). Differences in soils physical and chemical properties did not accuracy of the detection limits of ELISA when compared to GC-ECD results. Immunoassay technique is a suitable method for rapid and accurate measurement of DDT residue in mineral Lebanese soils

Dikloro Difenil Trikoloetan (Ddt)

OpenAIRE

Alfiah, Siti

2011-01-01

ABSTRACT Invention of Dikloro Difenil Trikoloetan (DDT) by Zeidler in 1874 was first began of syntetic insectiside discovery. DDT was classified in chlorinated hydrocarbons. Persistance of DDTin organism and environment have been forbidden to use in  many countries in the world. The resistance of DDT to mosquitoes and flies was reported in 1948. It was caused of change of metabolism, target site insensitivity, phisiology and behaviour mechanism. The problems of DDT could be solved by insectic...

Prenatal and postnatal exposure to DDT by breast milk analysis in Canary Islands.

Science.gov (United States)

Vall, Oriol; Gomez-Culebras, Mario; Puig, Carme; Rodriguez-Carrasco, Ernesto; Gomez Baltazar, Arelis; Canchucaja, Lizzeth; Joya, Xavier; Garcia-Algar, Oscar

2014-01-01

The use of p,p'-dichlorodiphenyltrichloroethane (DDT) has been banned since the late 1970s due to its toxicity. However, its long half-life makes it persistent in the environment and, consequently, almost everyone has DDT residues in the body. Human milk constitutes an ideal non-conventional matrix to investigate environmental chronic exposure to organochlorine compounds (OCs) residues. The study aimed to identify potential population risk factors of exposure to DDT due to the proximity to countries where it is still used. Seventy-two consecutive lactating women were prospectively included in Tenerife, Canary Islands (Spain). A validated questionnaire was used to obtain socioeconomic, demographics data, and daily habits during pregnancy. DDT levels in breast milk were measured by gas chromatography with-electron capture detector (GC-ECD). Anthropometrics measurements in newborns were obtained. Thirty-four out of 72 (47.2%) of the analysed milk samples presented detectable levels of DDT (mean: 0.92 ng/g), ranging between 0.08 to 16.96 ng/g. The socio-demographic variables did not significantly differ between detectable DDT and non-detectable DDT groups. We found positive association between DDT levels and vegetables (OR (95%CI): 1.23 (1.01-1.50)) and poultry meat (OR (95%CI): 2.05 (1.16-3.60)) consumption, and also between the presence of DDT in breast milk and gestational age (OR (95%CI): 0.59 (0.40-0.90)). DDT is present in breast milk of women at the time of delivery. Residual levels and the spread from countries still using DDT explain DDT detection from vegetables and from animal origin food. The presence of this compound in breast milk represents a pre- and postnatal exposure hazard for foetuses and infants due to chronic bioaccumulation and poor elimination, with possible deleterious effects on health. This data should be used to raise awareness of the risks of OCs exposure and to help establish health policies in order to avoid its use worldwide and thus, to

Prenatal and Postnatal Exposure to DDT by Breast Milk Analysis in Canary Islands

Science.gov (United States)

Vall, Oriol; Gomez-Culebras, Mario; Puig, Carme; Rodriguez-Carrasco, Ernesto; Gomez Baltazar, Arelis; Canchucaja, Lizzeth; Joya, Xavier; Garcia-Algar, Oscar

2014-01-01

Introduction The use of p,p′-dichlorodiphenyltrichloroethane (DDT) has been banned since the late 1970s due to its toxicity. However, its long half-life makes it persistent in the environment and, consequently, almost everyone has DDT residues in the body. Human milk constitutes an ideal non-conventional matrix to investigate environmental chronic exposure to organochlorine compounds (OCs) residues. The study aimed to identify potential population risk factors of exposure to DDT due to the proximity to countries where it is still used. Methods Seventy-two consecutive lactating women were prospectively included in Tenerife, Canary Islands (Spain). A validated questionnaire was used to obtain socioeconomic, demographics data, and daily habits during pregnancy. DDT levels in breast milk were measured by gas chromatography with-electron capture detector (GC-ECD). Anthropometrics measurements in newborns were obtained. Results Thirty-four out of 72 (47.2%) of the analysed milk samples presented detectable levels of DDT (mean: 0.92 ng/g), ranging between 0.08 to 16.96 ng/g. The socio-demographic variables did not significantly differ between detectable DDT and non-detectable DDT groups. We found positive association between DDT levels and vegetables (OR (95%CI): 1.23 (1.01–1.50)) and poultry meat (OR (95%CI): 2.05 (1.16–3.60)) consumption, and also between the presence of DDT in breast milk and gestational age (OR (95%CI): 0.59 (0.40–0.90)). Conclusions DDT is present in breast milk of women at the time of delivery. Residual levels and the spread from countries still using DDT explain DDT detection from vegetables and from animal origin food. The presence of this compound in breast milk represents a pre- and postnatal exposure hazard for foetuses and infants due to chronic bioaccumulation and poor elimination, with possible deleterious effects on health. This data should be used to raise awareness of the risks of OCs exposure and to help establish health policies

Biorremediación de suelo contaminado con el pesticida 1,1,1-tricloro-2,2’bis(p-clorofenil)etano (DDT) mediante protocolos de bioestimulación y adición de surfactante

OpenAIRE

Betancur Corredor, Bibiana

2013-01-01

Resumen: El 1,1,1-tricloro-2,2’bis(p-clorofenil)etano (DDT) ha sido usado desde la segunda guerra mundial para controlar enfermedades transmitidas por insectos en humanos y animales domésticos. El uso de estos insecticidas organoclorados se ha prohibido en la mayoría de los países debido a su persistencia en el ambiente, susceptibilidad de biomagnificación y potencial toxicidad a animales superiores. La biorremediación involucra el uso de microorganismos para degradar contaminantes orgánic...

Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation.

Science.gov (United States)

Lange, S; Viergutz, T; Simkó, M

2004-10-01

Low-frequency electromagnetic fields are suspected of being involved in carcinogenesis, particularly in processes that could be related to cancer promotion. Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial gamma-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1- and p16INK4a-expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1- and p16INK4a- levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR.

Distinct roles of the DmNav and DSC1 channels in the action of DDT and pyrethroids.

Science.gov (United States)

Rinkevich, Frank D; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S; Dong, Ke

2015-03-01

Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (para(ts)) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a para(ts1) allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in para(ts1) mutant flies was almost completely abolished in para(ts1);DSC1(-/-) double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w(1118A)), and the para(ts1);DSC1(-/-) double mutant flies were even more resistant to DDT compared to the DSC1 knockout or para(ts1) mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Abilities of Co-cultures of Brown-Rot Fungus Fomitopsis pinicola and Bacillus subtilis on Biodegradation of DDT.

Science.gov (United States)

Sariwati, Atmira; Purnomo, Adi Setyo; Kamei, Ichiro

2017-09-01

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is one of the pesticides that are hazardous for the environment and human health. Effective environmental-friendly treatment using co-cultures of fungi and bacteria is needed. In this study, the bacteria Bacillus subtilis at various volumes of 1, 3, 5, 7, and 10 mL (1 mL ≈ 6.7 × 10 8  CFU) were mixed into 10 mL of the brown-rot fungus Fomitopsis pinicola culture for degrading DDT during a 7-days incubation period. DDT was degraded by approximately 42% by F. pinicola during the 7-days incubation period. The addition of 10 mL of B. subtilis into F. pinicola culture showed the highest DDT degradation of approximately 86% during the 7-days incubation period. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl)ethylene) were detected as metabolic products from DDT degradation by co-cultures of F. pinicola and B. subtilis. Transformation pathway was proposed in which DDT was transformed into three pathways as follows: (1) dechlorination to DDD, (2) dehydrochlorination to DDE, and (3) formation of DDMU.

The transport of DDT from chylomicrons to adipocytes does not mimic triacylglycerol transport

Science.gov (United States)

Kohan, Alison B.; Vandersall, Abbey E.; Yang, Qing; Xu, Min; Jandacek, Ronald J.; Tso, Patrick

2012-01-01

Despite being banned in the U.S., organochlorine toxins such as DDT are frequently detected in human adipose tissue. The main route of exposure is through the consumption of contaminated foods and subsequent intestinal packaging of DDT into chylomicrons. These chylomicrons, which also contain dietary triacylglycerol (TG), are delivered directly to peripheral tissues without first being metabolized by the liver. The physiological process by which these compounds are delivered from chylomicrons to adipose is not well understood, but is clinically relevant since it bypasses first-pass metabolism. Based on its highly lipophilic nature, it has been assumed that DDT is transferred to peripheral tissues similar to TG; however, this has not been measured. Here, we use the lymph fistula rat to isolate chylomicrons containing both DDT and TG. These chylomicrons are the in vivo DDT delivery vehicle. Using 3T3-L1 adipocytes, we investigated the rate at which DDT transfers from chylomicrons to adipocytes, and mediators of this process. This novel approach closely approximates the in vivo DDT exposure route. We show that: 1) DDT repartitions from chylomicrons to adipocytes, 2) this transport does not require hydrolysis of TG within the chylomicron, and is stimulated by the inhibition of LPL, 3) albumin does not inhibit DDT uptake, 4) DDT dissolved in DMSO does not appropriately mimic in vivo DDT transport; and most importantly, 5) DDT uptake from chylomicrons does not mimic the uptake of TG from the same particles. Understanding these factors is important for designing interventions for human populations exposed to DDT. PMID:22885168

The Validation Of Influence Factors To DDT Concentration In Soil

International Nuclear Information System (INIS)

Kamal, Zainul; Poernomo, Herry

2000-01-01

Determination concentration of DDT in humidified land's and rising intensity has been done. The amount of natural soil was filled in poliethylene tube, and the amount of humadified soil was filled in order poliethylene tube. The solution of DDT-C sub.14 with volume of 10 ml and activity of 10 muCi was increased in those tube respectively, the latter it was resident for many time under shine. Sample of soil was took first week to sixthweek, it was crushed to reach homogenous, then it was counted by liquid scintillation counter. The experiment result indicated that the DDT content in the unilluminated soil for 1 week is < 0.1 ppb, for 2 week is 0.19 n 0.01 ppb, for 3 week is 1.95 n 0.32 ppb, for 4 week is 14.07 n 0.14 ppb, for 5 week is 3.67 n 0.21 ppb and for 6 week is 2.28 n 0.09 ppb. The DDT content in the humidified soil without sun illumination for 1 week is 0.25 n 0.07 ppb, for 2 week is 6.34 n 0.19 ppb, for 3 week is 9.33 n 0.80 ppb, for 4 week is 12.36 n 0.17 ppb, for 5 week is 4.58 n 0.15 ppb and for 6 week is 2.01 n 0.55 ppb. The DDT content in the natural soil illuminated by VIS for 1 week is 0.74 n 0.08 ppb, for 2 week is 7.48 n 0.14 ppb, for 3 week is 4.06 n 0.28 ppb, for 4 week is 13.16 n 0.20 ppb, for 5 week is 5.00 n 0.70 ppb and for 6 week is 2.03 n 0.03 ppb

40 CFR 129.101 - DDT, DDD and DDE.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false DDT, DDD and DDE. 129.101 Section 129... POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE. (a) Specialized definitions. (1) DDT Manufacturer means a manufacturer, excluding any source which is...

DDT and Malaria Prevention: Addressing the Paradox

Science.gov (United States)

Bouwman, Hindrik; van den Berg, Henk; Kylin, Henrik

2011-01-01

Background The debate regarding dichlorodiphenyltrichloroethane (DDT) in malaria prevention and human health is polarized and can be classified into three positions: anti-DDT, centrist-DDT, pro-DDT. Objective We attempted to arrive at a synthesis by matching a series of questions on the use of DDT for indoor residual spraying (IRS) with literature and insights, and to identify options and opportunities. Discussion Overall, community health is significantly improved through all available malaria control measures, which include IRS with DDT. Is DDT “good”? Yes, because it has saved many lives. Is DDT safe as used in IRS? Recent publications have increasingly raised concerns about the health implications of DDT. Therefore, an unqualified statement that DDT used in IRS is safe is untenable. Are inhabitants and applicators exposed? Yes, and to high levels. Should DDT be used? The fact that DDT is “good” because it saves lives, and “not safe” because it has health and environmental consequences, raises ethical issues. The evidence of adverse human health effects due to DDT is mounting. However, under certain circumstances, malaria control using DDT cannot yet be halted. Therefore, the continued use of DDT poses a paradox recognized by a centrist-DDT position. At the very least, it is now time to invoke precaution. Precautionary actions could include use and exposure reduction. Conclusions There are situations where DDT will provide the best achievable health benefit, but maintaining that DDT is safe ignores the cumulative indications of many studies. In such situations, addressing the paradox from a centrist-DDT position and invoking precaution will help design choices for healthier lives. PMID:21245017

HCH and DDT residues in human placentas in Murcia (Spain)

International Nuclear Information System (INIS)

Falcon, M.; Oliva, J.; Osuna, E.; Barba, A.; Luna, A.

2004-01-01

Organochlorinated insecticides are ubiquitous toxicants that are transplacentally transferred from mother to fetus and are reported to produce adverse health effects in pregnant woman and neonates. To investigate hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) exposure in pregnant woman, a total of 102 placentas were analyzed by a gas chromatograph equipped with electron capture detector. Organochlorine residues were found in 69.6% of the samples. Lindane was detected in 24.5%, α-HCH in 2.9%, β-HCH in 6.9%, p,p'-DDE in 44.1%, p,p'-DDT in 14.7% and p,p'-DDD in 10.8% of the samples. The pattern of dispersal by these substances in Murcia is similar to that described by different authors in other countries. Therefore, the past use of DDT and the present employment of lindane seem to be reflected in body tissues of the residents of this area

[Assessment of the MF59-adjuvanted pandemic influenza A/H1N1 vaccine. Systematic review of literature].

Science.gov (United States)

Ruiz-Aragón, J; Grande Tejada, A M; Márquez-Peláez, S; Molina Linde, J M; Yang, R

2013-10-01

To assess the efficacy and safety of MF59-adjuvanted pandemic influenza A/H1N1 vaccine in children. A systematic review of the literature was performed after searching the MedLine and Embase electronic databases, and manual search in specialties journals, with MeSH terms and and free terms. Inclusion criteria were clinical trials with children vaccinated with MF59-adjuvanted influenza A/H1N1 vaccine, compared with other vaccines doses with/without MF59-adjuvanted. The immunogenicity and safety of the vaccine was recorded. The quality of the studies included was assessed by CASPe checklist. Four clinical trials with moderate quality were selected. The local and systemic adverse effects were rare and mild, with no differences between groups. Seroconversion and seroprotection levels were higher with MF59-adjuvanted vaccines. Antibody titres were also higher with the adjuvant vaccines. The adjuvant vaccine has a good efficacy and safety profile. The adverse effects that may occur are common and appear similarly in both vaccination groups. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Synthesis of [methine-3H]DDT and its nitro-analog, and isotope effects in their enzyme-catalyzed dehydrochlorination

International Nuclear Information System (INIS)

Kurihara, N.; Ikemoto, Y.; Okutani, S.; Clark, A.G.

1989-01-01

[methine- 3 H]1,1-Di-(4-chlorophenyl)-2,2,2-trichloroethane ([methine- 3 H]DDT) and its di-(4-nitrophenyl) analog, both of high purity with a moderately high specific activity were prepared. Chloro-benzene was condensed with [1- 3 H]1-(4-chlorophenyl)-2,2,2-trichloro-ethanol, which has been synthesized by sodium boro[ 3 H]hydride reduction of 4-chlorophenyl trichloromethyl ketone. The purified [ 3 H]DDT had a specific activity of 0.77 Ci/mmol (28.49 GBq/mmol). [methine- 3 H]1,1-Diphenyl-2,2,2-trichloroethane was similarly synthesized and was nitrated to give [methine- 3 H]1,1-di-(4-nitrophenyl)-2,2,2-trichloro-ethane of 1.63 Ci/mmol (60.31 GBq/mmol). Dehydrochlorination with housefly enzyme (glutathione-dependent DDT dehydrochlorinase) showed a remarkable isotope effect. For DDT, the observed tritium isotope effect on V max /K m was 11.51±0.52. For the nitro-analog, the value was 11.3±1.2. We measured deuterium isotope effect on V max /K m for DDT in a competitive mode and obtained the value 4.19±0.34. Based on these values, the magnitude of intrinsic isotope effect values on DDT-dehydrochlorination reaction was discussed. (author)

Novel Chryseobacterium sp. PYR2 degrades various organochlorine pesticides (OCPs) and achieves enhancing removal and complete degradation of DDT in highly contaminated soil.

Science.gov (United States)

Qu, Jie; Xu, Yang; Ai, Guo-Min; Liu, Ying; Liu, Zhi-Pei

2015-09-15

Long term residues of organochlorine pesticides (OCPs) in soils are of great concerning because they seriously threaten food security and human health. This article focuses on isolation of OCP-degrading strains and their performance in bioremediation of contaminated soil under ex situ conditions. A bacterium, Chryseobacterium sp. PYR2, capable of degrading various OCPs and utilizing them as a sole carbon and energy source for growth, was isolated from OCP-contaminated soil. In culture experiments, PYR2 degraded 80-98% of hexachlorocyclohexane (HCH) or 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) isomers (50 mg L(-1)) in 30 days. A pilot-scale ex situ bioremediation study of highly OCP-contaminated soil augmented with PYR2 was performed. During the 45-day experimental period, DDT concentration was reduced by 80.3% in PYR2-augmented soils (35.37 mg kg(-1) to 6.97 mg kg(-1)) but by only 57.6% in control soils. Seven DDT degradation intermediates (metabolites) were detected and identified in PYR2-augmented soils: five by GC/MS: 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD), 1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene (DDE), 1-chloro-2,2-bis (4-chlorophenyl) ethylene (DDMU), 1-chloro-2,2-bis (4-chlorophenyl) ethane (DDMS), and dichlorobenzophenone (DBP); and two by LC/MS: 4-chlorobenzoic acid (PCBA) and 4-chlorophenylacetic acid (PCPA). Levels of metabolites were fairly stable in control soils but varied greatly with time in PYR2-augmented soils. Levels of DDD, DDMU, and DDE in PYR2-augmented soils increased from day 0 to day 30 and then decreased by day 45. A DDT biodegradation pathway is proposed based on our identification of DDT metabolites in PYR2-augmented systems. PYR2 will be useful in future studies of OCP biodegradation and in bioremediation of OCP-contaminated soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of a Simple Dipstick Assay for Operational Monitoring of DDT.

Science.gov (United States)

Ismail, Hanafy M; Kumar, Vijay; Singh, Rudra P; Williams, Christopher; Shivam, Pushkar; Ghosh, Ayan; Deb, Rinki; Foster, Geraldine M; Hemingway, Janet; Coleman, Michael; Coleman, Marlize; Das, Pradeep; Paine, Mark J I

2016-01-01

Indoor residual spraying (IRS) of DDT is used to control visceral leishmaniasis (VL) in India. However, the quality of spraying is severely compromised by a lack of affordable field assays to monitor target doses of insecticide. Our aim was to develop a simple DDT insecticide quantification kit (IQK) for monitoring DDT levels in an operational setting. DDT quantification was based on the stoichiometric release of chloride from DDT by alkaline hydrolysis and detection of the released ion using Quantab chloride detection strips. The assay was specific for insecticidal p,p`-DDT (LoQ = 0.082 g/m2). Bostik discs were effective in post spray wall sampling, extracting 25-70% of active ingredient depending on surface. Residual DDT was sampled from walls in Bihar state in India using Bostik adhesive discs and DDT concentrations (g p,p`-DDT/m2) were determined using IQK and HPLC (n = 1964 field samples). Analysis of 161 Bostik samples (pooled sample pairs) by IQK and HPLC produced excellent correlation (R2 = 0.96; Bland-Altman bias = -0.0038). IQK analysis of the remaining field samples matched HPLC data in identifying households that had been under sprayed, in range or over sprayed. A simple dipstick assay has been developed for monitoring DDT spraying that gives comparable results to HPLC. By making laboratory-based analysis of DDT dosing accessible to field operatives, routine monitoring of DDT levels can be promoted in low- and middle- income countries to maximise the effectiveness of IRS.

DDT concentration in fish from the Tapajós River in the Amazon region, Brazil.

Science.gov (United States)

Mendes, Rosivaldo de Alcântara; Lopes, Anna Sylmara da Costa; de Souza, Larissa Costa; Lima, Marcelo de Oliveira; Santos, Lourivaldo da Silva

2016-06-01

DDT and metabolites were measured in six species of fish collected from the Tapajós River in the village of Barreiras, near the town of Itaituba in the Brazilian Amazon region. The selected fish were the most consumed and economically important to the local people. DDT was used frequently in this region for malaria control. Fish samples were analyzed after extraction by microwave-assisted extraction in hexane/acetone (8:2, v/v) by gas chromatography with electron capture detector. Residues of op'-DDT and pp'-DDT and metabolites were detected, including pp'-DDE, pp'-DDD, op'-DDT, and op'-DDE, in 98% of the samples, with a greater abundance of pp'-DDT. Total DDT levels were 7.1-249.5 ng g(-1) wet weight (w.w). The DDE/DDT ratio was low, indicating recent exposure to DDT. The study area that may be related to generated waste used in public health campaigns to combat mosquitos (Anopheles spp.), still present in the Amazon environment, that transmit malaria. DDT levels and metabolites found in fish species do not present risks to human health because they are below acceptable limits for consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of aerobic exercise intervention on DDT degradation and oxidative stress in rats.

Science.gov (United States)

Li, Kefeng; Zhu, Xiaohua; Wang, Yuzhan; Zheng, Shuqian; Dong, Guijun

2017-03-01

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress. Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise treatment only to the DE group from the 1st day until the rats are killed. DDT levels in excrements, muscle, liver, serum, and hearts were analyzed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels were determined. Aerobic exercise accelerated the degradation of DDT primarily to DDE due to better oxygen availability and aerobic condition and promoted the degradation of DDT. Cumulative oxidative damage of DDT and exercise led to significant decrease of SOD level. Exercise resulted in consistent increase in SOD activity. Aerobic exercise enhanced activities of CAT and GSH-Px and promoted MDA scavenging. Results suggested that exercise can accelerate adaptive responses to oxidative stress and activate antioxidant enzymes activities. Exercise can also facilitate the reduction of DDT-induced oxidative damage and promoted DDT degradation. This study strongly implicated the positive effect of exercise training on DDT-induced liver oxidative stress.

The influence of small-scale interlayer heterogeneity on DDT removal efficiency for flushing technology

Science.gov (United States)

Wang, Xingwei; Chen, Jiajun

2017-06-01

With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9.47% and 11.28% under heterogeneous patterns 1 and 2, respectively. The DDT removal contributions of improving sweep efficiency for heterogeneous patterns 1 and 2 by foam flushing were 40.82% and 45.98%, and the contribution of dissolving capacity were 59.18% and 54.02%, respectively. The dissolving capacity of DDT played a major role in DDT removal efficiency by foam flushing under laboratory conditions. And the DDT removal contribution of significant improving sweep efficiency was higher than that of removal decline caused by weak solubilizing ability of foam film compared with solution flushing. The obtained results indicated that the difference of DDT removal efficiency by foam flushing was decreased under two different heterogeneous patterns with the increase of the contribution of improving foam flushing sweep efficiency. It suggested that foam flushing can reduce the disturbance from interlayer heterogeneity in remediating DDT contaminated heterogeneous medium.

Efficient transformation of DDT by peroxymonosulfate activated with cobalt in aqueous systems: Kinetics, products, and reactive species identification.

Science.gov (United States)

Qin, Wenxiu; Fang, Guodong; Wang, Yujun; Wu, Tongliang; Zhu, Changyin; Zhou, Dongmei

2016-04-01

Recently, sulfate radical ( [Formula: see text] ) based-advanced oxidation technologies (AOTs) have been attracted great attention in the remediation of contaminated soil and groundwater. In the present study, Co(2+) ions activated peroxymonosulfate (PMS) system was used to degrade 1, 1, 1-trichloro-2, 2'bis(p-chlorophenyl) ethane (DDT) in aqueous solutions. It was found that DDT was efficiently degraded in the PMS/Co(II) solutions within several hours, and the degradation efficiency of DDT was dependent on the concentrations of PMS and Co(II), and the optimum molar ratio of PMS and Co(II) was 50:1. The degradation kinetics of DDT were well described with pseudo-first-order equations over a range of temperature (10-40 °C), and the activation energy that was calculated with Arrhenius equation was 72.3 ± 2.6 kJ/mol. Electron paramagnetic resonance (EPR) and GC-MS techniques were applied to identify the intermediates and reactive species for DDT degradation. The results indicated that [Formula: see text] and OH were the main reactive species accounting for DDT degradation. Dichlorobenzophenone, 4-chlorobenzoic acid and benzylalcohol were the dominant intermediates for DDT degradation, and the likely degradation pathway of DDT was proposed on the basis of these identified products. Increasing pH inhibited the formation of [Formula: see text] and OH, and thus decreased the catalytic degradation of DDT. Cl(-) ion was found to significantly inhibit, while [Formula: see text] and dissolved oxygen had limited effects on DDT degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

DDT and Malaria Prevention: Addressing the Paradox

NARCIS (Netherlands)

Bouwman, H.; Berg, van den H.; Kylin, H.

2011-01-01

Background: The debate regarding dichlorodiphenyltrichloroethane (DDT) in malaria prevention and human health is polarized and can be classified into three positions: anti-DDT, centrist-DDT, pro-DDT. Objective: We attempted to arrive at a synthesis by matching a series of questions on the use of DDT

Remediation of DDT-contaminated water and soil by using pretreated iron byproducts from the automotive industry.

Science.gov (United States)

Satapanajaru, Tunlawit; Anurakpongsatorn, Patana; Pengthamkeerati, Patthra

2006-01-01

The objective of this study was to quantify the effectiveness of different pretreated iron byproducts from the automotive industry to degrade DDT [(1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane] in aqueous solutions and soil slurry. Iron byproducts from automotive manufacturing were pretreated by three different methods (heating, solvent and 0.5N HCl acid washing) prior to experimentation. All pretreated irons were used at 5% (wt v-1) to treat 0.014 mM (5 mgL-1) of DDT in aqueous solution. Among the pretreated irons, acid pretreated iron results in the fastest destruction rates, with a pseudo first-order degradation rate of 0.364 d-1. By lowering the pH of the DDT aqueous solution from 9 to 3, destruction kinetic rates increase more than 20%. In addition, when DDT-contaminated soil slurry (3.54 mg kg-1) was incubated with 5% (wt v-1) acid-pretreated iron, more than 90% destruction of DDT was observed within 8 weeks. Moreover, DDT destruction kinetics were enhanced when Fe(II), Fe(III) or Al(III) sulfate salts were added to the soil slurry, with the following order of destruction kinetics: Al(III) sulfate > Fe(III) sulfate > Fe(II) sulfate. These results provide proof-of concept that inexpensive iron byproducts of the automotive industry can be used to remediate DDT-contaminated water and soil.

DDT and metabolites

NARCIS (Netherlands)

Mirmigkou, S.; de Boer, J.; Alaee, M.

2016-01-01

Dichlorodiphenyltrichloroethane (DDT) is a well-known insecticide that was introduced and widely used during World War II. In total more than 4.5 million tonnes DDT have been produced. Although its use and production stopped worldwide during the 1970s, it was reintroduced in the 2000s as a malaria

Cycling and effects of ³⁶Cl labeled DDT on soil invertebrates

Energy Technology Data Exchange (ETDEWEB)

Dindal, Daniel L.

1978-08-01

DDT, radiolabeled with /sup 36/Cl (total activity of 10.2 mc) and applied in the field at the rate of 1.12 kg/ha, cannot be detected within decomposer microarthropods using liquid scintillation spectrometry. Soil microarthropods exhibit both positive and negative responses to direct and indirect effects of DDT. Faunal simplification (decreased diversity) resulting from pesticide application as reported by many others does not apply to the oribatid and prostigmatid mites of the old field. New colonization is possible by some species of Acari as a result of DDT application. Soil microbial respiration is enhanced by a single DDT application of 1 kg/ha. No apparent relationships exist between the increased microbial respiration and soil microarthropod population dynamics in this DDT treated old field. No apparent relationships exist between soil pH, moisture levels, texture and soil microarthropod population dynamics. Microarthropod community structure (species diversity and richness, interspecific relationships and similarity) are definitely affected by a single application of DDT. The Prostigmata are the most numerous mites in the soil of an old field in central Ohio. Vertebrate predators feeding on terrestrial snails may be subjected to magnified concentrations of DDT residues. Coprophagic decomposer organisms feeding on snail feces will be subject to much larger DDT concentrations. Terrestrial snails represented by Cepaea and Otala are not killed by acute oral doses of DDT. Within a three year period after a single application of DDT no effects on the soil faunal populations were seen below 3 cm of soil.

A Caprine Herpesvirus 1 Vaccine Adjuvanted with MF59™ Protects against Vaginal Infection and Interferes with the Establishment of Latency in Goats

Science.gov (United States)

Marinaro, Mariarosaria; Rezza, Giovanni; Del Giudice, Giuseppe; Colao, Valeriana; Tarsitano, Elvira; Camero, Michele; Losurdo, Michele; Buonavoglia, Canio; Tempesta, Maria

2012-01-01

The immunogenicity and the efficacy of a beta-propiolactone-inactivated caprine herpesvirus 1 (CpHV-1) vaccine adjuvanted with MF59™ were tested in goats. Following two subcutaneous immunizations, goats developed high titers of CpHV-1-specific serum and vaginal IgG and high serum virus neutralization (VN) titers. Peripheral blood mononuclear cells (PBMC) stimulated in vitro with inactivated CpHV-1 produced high levels of soluble IFN-gamma and exhibited high frequencies of IFN-gamma producing cells while soluble IL-4 was undetectable. On the other hand, control goats receiving the inactivated CpHV-1 vaccine without adjuvant produced only low serum antibody responses. A vaginal challenge with virulent CpHV-1 was performed in all vaccinated goats and in naïve goats to assess the efficacy of the two vaccines. Vaginal disease was not detected in goats vaccinated with inactivated CpHV-1 plus MF59™ and these animals had undetectable levels of infectious challenge virus in their vaginal washes. Goats vaccinated with inactivated CpHV-1 in the absence of adjuvant exhibited a less severe disease when compared to naïve goats but shed titers of challenge virus that were similar to those of naïve goats. Detection and quantitation of latent CpHV-1 DNA in sacral ganglia in challenged goats revealed that the inactivated CpHV-1 plus MF59™ vaccine was able to significantly reduce the latent viral load when compared either to the naïve goats or to the goats vaccinated with inactivated CpHV-1 in the absence of adjuvant. Thus, a vaccine composed of inactivated CpHV-1 plus MF59™ as adjuvant was strongly immunogenic and induced effective immunity against vaginal CpHV-1 infection in goats. PMID:22511971

A caprine herpesvirus 1 vaccine adjuvanted with MF59™ protects against vaginal infection and interferes with the establishment of latency in goats.

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Mariarosaria Marinaro

Full Text Available The immunogenicity and the efficacy of a beta-propiolactone-inactivated caprine herpesvirus 1 (CpHV-1 vaccine adjuvanted with MF59™ were tested in goats. Following two subcutaneous immunizations, goats developed high titers of CpHV-1-specific serum and vaginal IgG and high serum virus neutralization (VN titers. Peripheral blood mononuclear cells (PBMC stimulated in vitro with inactivated CpHV-1 produced high levels of soluble IFN-gamma and exhibited high frequencies of IFN-gamma producing cells while soluble IL-4 was undetectable. On the other hand, control goats receiving the inactivated CpHV-1 vaccine without adjuvant produced only low serum antibody responses. A vaginal challenge with virulent CpHV-1 was performed in all vaccinated goats and in naïve goats to assess the efficacy of the two vaccines. Vaginal disease was not detected in goats vaccinated with inactivated CpHV-1 plus MF59™ and these animals had undetectable levels of infectious challenge virus in their vaginal washes. Goats vaccinated with inactivated CpHV-1 in the absence of adjuvant exhibited a less severe disease when compared to naïve goats but shed titers of challenge virus that were similar to those of naïve goats. Detection and quantitation of latent CpHV-1 DNA in sacral ganglia in challenged goats revealed that the inactivated CpHV-1 plus MF59™ vaccine was able to significantly reduce the latent viral load when compared either to the naïve goats or to the goats vaccinated with inactivated CpHV-1 in the absence of adjuvant. Thus, a vaccine composed of inactivated CpHV-1 plus MF59™ as adjuvant was strongly immunogenic and induced effective immunity against vaginal CpHV-1 infection in goats.

Preconception serum 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane and B-vitamin status: independent and joint effects on women's reproductive outcomes.

Science.gov (United States)

Ouyang, Fengxiu; Longnecker, Matthew P; Venners, Scott A; Johnson, Sara; Korrick, Susan; Zhang, Jun; Xu, Xiping; Christian, Parul; Wang, Mei-Cheng; Wang, Xiaobin

2014-12-01

Although preconception 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane (DDT) exposure and B-vitamin deficiencies have each been shown to negatively affect human reproductive outcomes, little is known about their joint effect. We sought to examine whether B-vitamin sufficiency protects against adverse effects of DDT on clinical pregnancy (CP) and subclinical early pregnancy loss (EPL). We measured preconception concentrations of plasma B vitamins (vitamin B-6, vitamin B-12, and folate) and serum total DDT [sum of p,p' and o,p' isomers of DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] in 291 nulligravid women from Anhui, China, who were studied in 1996-1998. The women were followed prospectively from the time they stopped contraception until CP (gestational age ≥42 d) or 12 mo (whichever occurred first). EPL was identified by using daily urinary human chorionic gonadotropin. The women were categorized according to B-vitamin status (deficiency compared with sufficiency) and DDT concentration (high compared with low). Of 291 study women, a total of 385 conceptions (31% of which ended in EPL) and 265 CPs occurred. Compared with women with adequate B-vitamins and low DDT, incidence rates of CP were reduced in women with B-vitamin deficiency and a high DDT concentration (P vitamin B-12, DDT was not associated with the incidence of CP; in contrast, in women with vitamin B-12 deficiency, high DDT was associated with a lower incidence of CP (HR: 0.44; 95% CI: 0.23, 0.84); and the test for interaction was significant (P vitamin B-12 and folate sufficiency may help protect against adverse reproductive effects of DDT exposure. Additional studies are needed to confirm our findings. © 2014 American Society for Nutrition.

Protective Efficacy of Vitamins C and E on p,p′-DDT-Induced Cytotoxicity via the ROS-Mediated Mitochondrial Pathway and NF-κB/FasL Pathway

Science.gov (United States)

Jin, Xiaoting; Song, Li; Liu, Xiangyuan; Chen, Meilan; Li, Zhuoyu; Cheng, Long; Ren, Hua

2014-01-01

Dichlorodiphenoxytrichloroethane (DDT) is a known persistent organic pollutant and liver damage toxicant. However, there has been little emphasis on the mechanism underlying liver damage toxicity of DDT and the relevant effective inhibitors. Hence, the present study was conducted to explore the protective effects of vitamin C (VC) and vitamin E (VE) on the cytotoxicity of DDT in HL-7702 cells and elaborate the specific molecular mechanisms. The results demonstrated that p,p′-DDT exposure at over 10 µM depleted cell viability of HL-7702 cells and led to cell apoptotic. p,p′-DDT treatment elevated the level of reactive oxygen species (ROS) generation, induced mitochondrial membrane potential, and released cytochrome c into the cytosol, with subsequent elevations of Bax and p53, along with suppression of Bcl-2. In addition, the activations of caspase-3 and -8 were triggered. Furthermore, p,p′-DDT promoted the expressions of NF-κB and FasL. When the cells were exposed to the NF-κB inhibitor (PDTC), the up-regulated expression of FasL was attenuated. Strikingly, these alterations caused by DDT treatment were prevented or reversed by the addition of VC or VE, and the protective effects of co-treatment with VC and VE were higher than the single supplement with p,p′-DDT. Taken together, these findings provide novel experimental evidences supporting that VC or/and VE could reduce p,p′-DDT-induced cytotoxicity of HL-7702 cells via the ROS-mediated mitochondrial pathway and NF-κB/FasL pathway. PMID:25464339

UPTAKE AND PHYTOTRANSFORMATION OF O,P'-DDT AND P,P'-DDT BY AXENICALLY CULTIVATED AQUATIC PLANTS

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The uptake and phytotransformation of o,p'-DDT and p,p'-DDT were investigated in vitro using three axenically cultivated aquatic plants: parrot feather (Mariophyllum aquaticum), duckweed (Spirodela oligorrhiza), and elodea (Elodea canadensis). The decay profile of DDT from the aq...

DDT Exposure in Utero and Breast Cancer.

Science.gov (United States)

Cohn, Barbara A; La Merrill, Michele; Krigbaum, Nickilou Y; Yeh, Gregory; Park, June-Soo; Zimmermann, Lauren; Cirillo, Piera M

2015-08-01

Currently no direct evidence links in utero dichlorodiphenyltrichloroethane (DDT) exposure to human breast cancer. However, in utero exposure to another xenoestrogen, diethylstilbestrol, predicts an increased breast cancer risk. If this finding extends to DDT, it could have far-reaching consequences. Many women were heavily exposed in utero during widespread DDT use in the 1960s. They are now reaching the age of heightened breast cancer risk. DDT exposure persists and use continues in Africa and Asia without clear knowledge of the consequences for the next generation. In utero exposure to DDT is associated with an increased risk of breast cancer. This was a case-control study nested in a prospective 54-year follow-up of 9300 daughters in the Child Health and Development Studies pregnancy cohort (n = 118 breast cancer cases, diagnosed by age 52 y and 354 controls matched on birth year). Kaiser Foundation Health Plan members who received obstetric care in Alameda County, California, from 1959 to 1967, and their adult daughters participated in the study. Daughters' breast cancer diagnosed by age 52 years as of 2012 was measured. Maternal o,p'-DDT predicted daughters' breast cancer (odds ratio fourth quartile vs first = 3.7, 95% confidence interval 1.5-9.0). Mothers' lipids, weight, race, age, and breast cancer history did not explain the findings. This prospective human study links measured DDT exposure in utero to risk of breast cancer. Experimental studies are essential to confirm results and discover causal mechanisms. Findings support classification of DDT as an endocrine disruptor, a predictor of breast cancer, and a marker of high risk.

Assessment of DDT and Metabolites in Soil and Sediment of Potentially Contaminated Areas of Belém, Amazon Region, Brazil.

Science.gov (United States)

Rodrigues, Andreia Oliveira; de Souza, Larissa Costa; da Silva Rocha, Cássia Christina; da Costa, Amilton Cesar Gomes; de Alcântara Mendes, Rosivaldo

2017-07-01

The aim of this study was to evaluate the distribution of DDT and metabolites in surface soils and soil profiles from two areas containing deposits of obsolete pesticides in Belém, Amazon Region, Brazil. DDT and metabolites were extracted by microwave assisted extraction and analyzed by gas chromatography with electron capture detection. Concentrations of total DDT in surface soil samples ranged from 64.22 mg kg -1 in area 1 (A1) to 447.84 mg kg -1 in area 2 (A2). Lower levels were found in soil profiles than at the surface (6.21-21.17 mg kg -1 in A1 and 36.13-113.66 mg kg -1 in A2). pp'-DDT, pp'-DDE and pp'-DDD were detected in sediments at levels of 2.01, 0.96 and 0.35 mg kg -1 , respectively. The ratio (DDE + DDD)/ΣDDT was low indicating the recent introduction of DDT to the environment in the two study areas, through the volatilization and atmospheric deposition of the obsolete pesticides.

Effects on forest birds of DDT used for gypsy moth control in Pennsylvania

Science.gov (United States)

Hotchkiss, N.; Pough, R.H.

1946-01-01

1. Systematic censuses of the birds on three 40-acre tracts of forest near Scranton, Lackawanna County, Pennsylvania, were made between May 1 and June 27, 1945, to determine the breeding populations....2. Between May 24 and June 1 a 600-acre area enclosing the first (Mile Square) was sprayed by airplane with DDT in oil solution at 5 pounds per acre. On June 9 a 350-acre area enclosing the second tract (Maple Lake) was sprayed with 1pound of DDT per acre. The third tract (Check) was not treated....3. Within 48 hours after treatment of the Mile Square tract, five sick birds were found with symptoms of DDT poisoning, and all died. Two other dead birds were found, and two nests apparently were abandoned. Species involved were red-eyed vireo (3), black-and-white warbler, black-throated blue warbler (nest abandoned), ovenbird (bird died, nest abandoned), redstart, and scarlet tanager....Within 48 hours after application of DDT to the final portion of the tract (on June 1) the population of living birds appeared to have been much reduced, and this condition continued. Before spraying the population total for all species was 1.6 pairs (3.2 birds) per acre. Three days after spraying had been completed there were only two singing males in the entire area; but on June 13 the estimated population was 0.5 bird per acre.....4. After DDT was applied to the Maple Lake tract, careful watch was kept for changes in the bird population and as to nest conditions there and on the Check tract. The apparent total reduction for all species in the Maple Lake tract was from 2.7 pairs to 2.6 pairs per acre; and in the Check tract from 2.7 pairs to 2.4 pairs per acre. Neither these changes nor the observed abandonment of nests and nestling mortality could be attributed to use of DDT.

p,p'-Dichlorodiphenyltrichloroethane (p,p'-DDT) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) repress prostate specific antigen levels in human prostate cancer cell lines.

Science.gov (United States)

Wong, Lilian I L; Labrecque, Mark P; Ibuki, Naokazu; Cox, Michael E; Elliott, John E; Beischlag, Timothy V

2015-03-25

Despite stringent restrictions on their use by many countries since the 1970s, the endocrine disrupting chemicals, DDT and DDE are still ubiquitous in the environment. However, little attention has been directed to p,p'-DDT and the anti-androgen, p,p'-DDE on androgen receptor (AR) target gene transcription in human cells. Inhibitors of androgenic activity may have a deleterious clinical outcome in prostate cancer screens and progression, therefore we determined whether environmentally relevant concentrations of p,p'-DDT and p,p'-DDE negatively impact AR-regulated expression of prostate-specific antigen (PSA), and other AR target genes in human LNCaP and VCaP prostate cancer cells. Quantitative real-time PCR and immuno-blotting techniques were used to measure intracellular PSA, PSMA and AR mRNA and protein levels. We have shown for the first time that p,p'-DDT and p,p'-DDE repressed R1881-inducible PSA mRNA and protein levels in a dose-dependent manner. Additionally, we used the fully automated COBAS PSA detection system to determine that extracellular PSA levels were also significantly repressed. These chemicals achieve this by blocking the recruitment of AR to the PSA promoter region at 10 μM, as demonstrated by the chromatin immunoprecipitation (ChIP) in LNCaP cells. Both p,p'-DDT and p,p'-DDE repressed R1881-inducible AR protein accumulation at 10 μM. Thus, we conclude that men who have been exposed to either DDT or DDE may produce a false-negative PSA test when screening for prostate cancer, resulting in an inaccurate clinical diagnosis. More importantly, prolonged exposure to these anti-androgens may mimic androgen ablation therapy in individuals with prostate cancer, thus exacerbating the condition by inadvertently forcing adaptation to this stress early in the disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Functional recovery after experimental RPE debridement, mfERG studies in a porcine model

DEFF Research Database (Denmark)

Sørensen, Nina Buus; Lassota, Nathan; Kyhn, Maria Voss

2013-01-01

BACKGROUND: The correlation between histologically identified regeneration of retinal pigment epithelium (RPE) and functional outcome measured by multifocal electroretinography (mfERG) following surgical debridement is examined in a porcine model. In humans, visual acuity is reduced in diseases......, and by brushing the Bruch's membrane with a silicone catheter. Immediately following surgery (baseline) and after 2 and 6 weeks respectively, the animals were examined by mfERG, fundus photographs (FPs), fluorescein angiograms (FAs), and histopathology. RESULTS: The mfERG P1 amplitude was decreased 2 weeks (T2....... CONCLUSION: This is the first study to show that the histological regeneration of hypopigmented RPE correlates to a return of the retinal function, measured by mfERG....

DDT-induced feminization of gull embryos

International Nuclear Information System (INIS)

Fry, D.M.; Toone, C.K.

1981-01-01

Injection of DDT [1, 1, 1-trichloro-2,2-bis(p-chlorophenyl)ethane] into gull eggs at concentrations comparable to those found in contaminated seabird eggs in 1970 induces abnormal development of ovarian tissue and oviducts in male embryos. Developmental feminization of males is associated with inability to breed as adults and may explain the highly skewed sex ratio and reduced number of male gulls breeding on Santa Barbara Island in southern California

Screening of organochlorine insecticides (DDT and heptachlor in dry fish available in Bangladesh

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Md. Nurul Huda Bhuiyan

2008-06-01

Full Text Available The concentrations of organochlorine insecticides DDT and heptachlor were investigated to estimate the current status of insecticides used in dry fish. The most popular dry fish– ribbon fish (Chhuri, shrimp (Chingri and bombay duck (Loittya were selected for this study and these dry fishes were collected from different markets of Dhaka and Chittagong. The range of DDT used in all the samples was 3.038 ppb to 874.966 ppb. The range of DDT in ribbon fish 131.611 ppb to 149.430 ppb, in shrimp 3.038 ppb to 318.206 ppb and in bombay duck 61.918 ppb to 874.966 ppb was found. The range of heptachlor used in all the samples was 0.682 ppb to 5.464 ppb. The range of heptachlor in ribbon fish 1.710 ppb to 2.306 ppb, in shrimp 0.682 ppb to 3.806 ppb and in bombay duck 1.762 ppb to 5.464 ppb was found. The heptachlor was not found in ribbon fish (CTG-2, shrimp (DHK-2 and CTG-1 and bombay duck (DHK-1. The concentration of heptachlor in dry fish compare to DDT was found too much less.

Measurement of DDT fluxes from a historically treated agricultural soil in Canada.

Science.gov (United States)

Kurt-Karakus, Perihan Binnur; Bidleman, Terry F; Staebler, Ralf M; Jones, Kevin C

2006-08-01

Organocohlorine pesticide (OCP) residues in agricultural soils are of concern due to the uptake of these compounds by crops, accumulation in the foodchain, and reemission from soils to the atmosphere. Although it has been about three decades since DDT was banned for agricultural uses in Canada, residues persist in soils of some agricultural areas. Emission of DDT compounds to the atmosphere from a historically treated field in southern Ontario was determined in fall 2004 and spring 2005. The sigmaDDTs concentration in the high organic matter (71%) soil was 19 +/- 4 microg g(-1) dry weight. Concentration gradients in the air were measured at 5, 20, 72, and 200 cm above soil using glass fiber filter-polyurethane foam cartridges. Air concentrations of sigmaDDTs averaged 5.7 +/- 5.1 ng m(-3) at 5 cm and decreased to 1.3 +/- 0.8 ng m(-3) at 200 cm and were 60-300 times higher than levels measured at a background site 30 km away. Soil-air fugacity fractions, fs/(fs + fa), of p,p'-DDE, p,p'-DDD, and p,p'-DDT ranged from 0.42 to 0.91 using air concentrations measured above the soil and > or = 0.99 using background air concentrations, indicating that the soil was a net source to the background air. Fractionation of DDT compounds during volatilization was predicted using either liquid-phase vapor pressures (PL) or octanol-air partition coefficients (KOA). Relative emissions of p,p'-DDE and p,p'-DDT were better described by PL than KOA, whereas either PL or KOA successfully accounted for the fractionation of p,p'-DDT and o,p'-DDT. Soil-to-air fluxes were calculated from air concentration gradients and turbulent exchange coefficients determined from micrometeorological measurements. Average fluxes of sigmaDDTs were 90 +/- 24 ng m(-2) h(-1) in fall and 660 +/- 370 ng m(-2) h(-1) in spring. Higher soil temperatures in spring accounted for the higher fluxes. A volatilization half-life of approximately 200 y was estimated for sigmaDDT in the upper 5 cm of the soil column, assuming

Effects on g2/m phase cell cycle distribution and aneuploidy formation of exposure to a 60 Hz electromagnetic field in combination with ionizing radiation or hydrogen peroxide in l132 nontumorigenic human lung epithelial cells.

Science.gov (United States)

Jin, Hee; Yoon, Hye Eun; Lee, Jae-Seon; Kim, Jae-Kyung; Myung, Sung Ho; Lee, Yun-Sil

2015-03-01

The aim of the present study was to assess whether exposure to the combination of an extremely low frequency magnetic field (ELF-MF; 60 Hz, 1 mT or 2 mT) with a stress factor, such as ionizing radiation (IR) or H2O2, results in genomic instability in non-tumorigenic human lung epithelial L132 cells. To this end, the percentages of G2/M-arrested cells and aneuploid cells were examined. Exposure to 0.5 Gy IR or 0.05 mM H2O2 for 9 h resulted in the highest levels of aneuploidy; however, no cells were observed in the subG1 phase, which indicated the absence of apoptotic cell death. Exposure to an ELF-MF alone (1 mT or 2 mT) did not affect the percentages of G2/M-arrested cells, aneuploid cells, or the populations of cells in the subG1 phase. Moreover, when cells were exposed to a 1 mT or 2 mT ELF-MF in combination with IR (0.5 Gy) or H2O2 (0.05 mM), the ELF-MF did not further increase the percentages of G2/M-arrested cells or aneuploid cells. These results suggest that ELF-MFs alone do not induce either G2/M arrest or aneuploidy, even when administered in combination with different stressors.

DNA micro array analysis of yeast global genome expression in response to ELF-MF exposure

International Nuclear Information System (INIS)

Shimizu, K.; Yamamoto, T.; Ishibashi, T.; Kyoh, B.

2002-01-01

There is wide spread public concern over the possible health risk of ELF-MF. Electromagnetic fields may produce a variety of effects in several biological systems, including the elevation of cancer risk and reduction of cell growth. Epidemiological studies have shown weak correlations between the exposure to ELF and the incidence of several cancers, but negative studies have also been reported. Moreover, there are some reports that basic biological events such as the cell cycle and DNA replication were affected by exposure to MF. However, to date the molecular mechanism of the MF effect on living organism is not clear. In this study, we used yeast DNA micro array to examine the transcriptional profile of all genes in response to ELF-MF. A few years ago it was difficult to carry out a global gene expression study to identify important genes regarding ELF-MF, however, today DNA micro arrays allow gene regulation in response to high density ELF-MF exposure. Thus we used micro array to analyze changes in mRNA abundance during ELF-MF exposure

The hormonal effects of long-term DDT exposure on malaria vector-control workers in Limpopo Province, South Africa

International Nuclear Information System (INIS)

Dalvie, M.A.; Myers, J.E.; Lou Thompson, Mary; Dyer, Silke; Robins, T.G.; Omar, Shaheed; Riebow, John; Molekwa, Josef; Kruger, Phillip; Millar, R.

2004-01-01

DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] compounds, used in many developing countries, including South Africa, for the control of malaria vectors, have been shown to be endocrine disruptors in vitro and in vivo. The study hypothesis was that male malaria vector-control workers highly exposed to DDT in the past should demonstrate clinically significant exposure-related anti-androgenic and/or estrogenic effects that should be reflected in abnormalities in reproductive hormone levels. A cross-sectional study of 50 workers from three camps situated near the Malaria Control Center (MCC) in Tzaneen was performed. Tests included blood sampling before and after a gonadotropin-releasing hormone (GnRH) challenge (100 μg). Serum o'p' and p'p' isomers of DDE, DDT, and DDD and basal and post-GnRH challenge hormone levels, including luteinizing hormone, follicle-stimulating hormone, testosterone, sex hormone-binding globulin, estradiol (E2), and inhibin, were measured. The mean number of years worked at the MCC was 15.8±7.8 years and the mean serum DDT was 94.3±57.1 μg/g of lipid. Mean baseline E2 levels (62.4±29.9 pg/mL) exceeded the laboratory reference range. Associations between DDT exposure measures (years worked at the MCC and DDT compounds) and hormonal outcomes were weak and inconsistent. The most important finding was a positive relationship of baseline E2 and baseline testosterone with DDT compounds, especially with p'p'-DDT and -DDD. The strongest association found, adjusted for age and SHBG, was between baseline estradiol and p'p'-DDT (β-circumflex=1.14±0.33 pg/mL/μg/g lipid, P=0.001, R 2 =0.31, n=46). An overall anti-androgenic mechanism best explains the results, but with a number of inconsistencies. Associations might be due to chance, as multiple comparisons were made. The results therefore do not suggest an overt anti-androgenic or estrogenic effect of long-term DDT exposure on hormone levels, but correlations do exist in a manner that is not

Association between lung function in adults and plasma DDT and DDE levels: results from the Canadian Health Measures Survey.

Science.gov (United States)

Ye, Ming; Beach, Jeremy; Martin, Jonathan W; Senthilselvan, Ambikaipakan

2015-05-01

Although DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane] has been banned in many countries since the 1970s, it may still pose a risk to human respiratory health. In agriculture, DDT exposures have been associated with asthma and chronic bronchitis. However, little is known about the effect of DDT on lung function. We used data on 1,696 participants 20-79 years of age from the Canadian Health Measures Survey (CHMS) and conducted multiple regression analysis to estimate associations between plasma p,p´-DDT/DDE and lung function. Almost all participants (> 99.0%) had detectable concentrations of plasma p,p´-DDE, but only 10.0% had detectable p,p´-DDT. Participants with detectable p,p´-DDT had significantly lower mean FVC (difference = 311 mL; 95% CI: -492, -130; p = 0.003) and FEV1 (difference = 232 mL; 95% CI: -408, -55; p = 0.015) than those without. A 100-ng/g lipid increase in plasma p,p´-DDE was associated with an 18.8-mL decrease in mean FVC (95% CI: -29, -9) and an 11.8-mL decrease in mean FEV1 (95% CI: -21, -3). Neither exposure was associated with FEV1/FVC ratio or FEF25%-75%. DDT exposures, which may have occurred decades ago, were still detectable among Canadians. Plasma DDT and DDE were negatively associated with lung function parameters. Additional research on the potential effects of DDT use on lung function is warranted.

Development of a Simple Scheme for Prediction of Flame Acceleration and DDT

International Nuclear Information System (INIS)

Kim, Han Chul; Park, Jae Hong; Lee, Jung Jae; Kang, Han Byeol; Sung, Key Yong; Seul, Kwang Won; Cho, Song Won; Ryu, In Chul

2010-01-01

Hydrogen combustion phenomenology during severe accidents in nuclear power plants has been a safety issue. Especially, flame acceleration (FA) and Deflagration-to-Detonation Transition (DDT) are important because of their possible destructive impact on the containment or plant systems in it. Accordingly, it is the design goal to avoid FA and DDT for the hydrogen mitigation system. As a result from extensive effort dedicated to resolve the hydrogen issue, compiled information on the FA and DDT has been provided by the NEA. The FA criterion was suggested in terms of the mixture expansion ratio σ , and the criterion for onset of DDT was based on the greatness of the geometrical size of the reactive system compared with the detonation cell width λ of the average mixture composition. The DDT onset criterion reflects the current state of knowledge based on the experimental database; however, the criterion is not sufficient but a necessary condition. Therefore, it should be noted that satisfying this condition means that the possibility of DDT cannot be removed. Based on this information, a simple in-house computer program for evaluation of the FA and DDT possibility, named DEFEND (Determination of Flame Evolution and DDT), is being developed. The database for the density of combustion products analyzed by KEPCO-E and C with the CHEMKIN code was used for FA estimation. The correlation developed by Chan and Wojciechoski is incorporated for determination of the critical expansion ratio σ critical

Adsorption of DDT and PCB by Nanomaterials from Residual Soil

Science.gov (United States)

Taha, Mohd Raihan; Mobasser, Shariat

2015-01-01

This paper presents the findings of a study on adsorption of dichlorodiphenythreechloroethen (DDT) and polychlorinated biphenyls (PCBs) on three nanomaterials including Multi walled Carbon Nanotube (MWNT), nano-clay and nano-alumina. DDT and PCBs are of significant concern due their high toxicity and long environmental half-lives. Experiments were conducted using batch adsorption procedures at different DDT and PCBs concentrations, from 10 to 60 mg/L. The amounts of MWNT, nano-clay and Nano-alumina used were 0.25%, 0.50%, 0.75%, 1%, 2% and 10%. The adsorption of PCBs solution onto the MWNT, nano-clay and nano-alumina was characterized by an initial rapid adsorption which eventually became constant within 22, 20, and 17 hours, respectively. The adsorption of DDT solution onto the MWNT, nano-clay and nano-alumina was also characterized by an initial rapid adsorption which gradually became constant within 22, 22 and 16 hours, respectively. Results of this study indicated that MWNT was a better adsorbent material compared to nano-clay and nano-alumina for both contaminants in this study. While at 10% of MWNT 88.9% and 77% of DDT and PCB were removed by MWNT, respectively. The effect of pH and temperature were also investigated. PMID:26659225

Turbulent combustion and DDT events as an upper bound for hydrogen mitigation techniques

International Nuclear Information System (INIS)

Dorofeev, S.B.

1997-01-01

A brief review is presented on the limiting conditions for fast combustion regimes (accelerated flames, fast turbulent deflagrations, and DDT events), and on their effect on confining structures. Main attention is given to hydrogen-air-steam mixtures typical for severe accidents in nuclear power plants. Comparison is made of the pressure loads resulting from different combustion regimes. Transient wave processes are shown to be very important for description of the pressure loads. Different limiting conditions are discussed for DDT being the most dangerous combustion event. Possibility of DDT is shown to be limited by the geometrical scale. Detailed description is presented for DDT criterion based on the minimum scale requirement for detonation formation. This criterion gives a conservative estimate that DDT is impossible, if characteristic size of combustible mixture is less than 7 detonation cell widths of the mixture. Conditions limiting possibility of flame acceleration are also discussed. (author)

Defect accumulation in welded joints of 12Kh1MF steel steam pipelines during creep

International Nuclear Information System (INIS)

Anokhov, A.E.; Alekhova, I.A.

1982-01-01

Technique for investigation of micropore accumulation in 12Kh1MF steel welded joints is proposed. The micropore density in different zones of welded joints in non-uniform. It is shown that failure localization in welded joint in the softening zone during the creep takes place due to the micropore priority accumulation in this zone. It is found out that accumulation of residual deformations in different zones of 12Kh1MF welded joints under creep runs more uniformly as the level of working stresses decreases and test duration increases

Fate of DDT in grape juice when fermented and distilled into arak

International Nuclear Information System (INIS)

Kawar, N.S.

1975-01-01

Since DDT is still used on grapevines to control insect pests, the fate of this insecticide in grape juice fermented and distilled into arak was investigated. Fermentation of the juice resulted in extensive conversion of DDT to DDD. Distillation of the fermented juice resulted in further conversion of DDT to DDD. Moreover, the major portion of both DDT and DDD remained in the undistilled fraction. The second distillation resulted in further distribution of DDT and DDD among the four fractions, thus leaving very low levels of both compounds in the finished product. DDT residue in arak constituted only 2% of the amount added to the fresh juice. (author)

Phenobarbital treatments lower DDT body burden in rhesus monkeys

Energy Technology Data Exchange (ETDEWEB)

Ferguson, P.W.; Clark, C.R.; Gee, S.J.; Krieger, R.I.

1981-01-01

Decreased DDT, DDD, DDE in blood and DDA in urine followed phenobarbital treatments (10 mg/kg/day, 11 days, intramuscular (im)) in three male rhesus monkeys (Macaca mulatta). Animals were fed DDT diets containing up to 500 ppm DDT during a 3-year period. Induction of liver monooxygenases was confirmed by reduced in vivo antipyrine plasma half-life and increased in vitro oxidation rates of dihydroisodrin, p-nitroanisole and benz(alpha)pyrene by homogenates of liver obtained from closed needle biopsy. Chlorohydrocarbon blood levels significantly decreased during the induction period (days 1-11). Concentrations on day 28 were at or below pre-DDT exposure levels. Urine DDA gradually decreased in all monkeys from days 16 to 28.

Safety and immunogenicity of an MF59-adjuvanted A/H1N1 pandemic influenza vaccine in children from three to seventeen years of age.

Science.gov (United States)

Knuf, Markus; Leroux-Roels, Geert; Rümke, Hans C; Abarca, Katia; Rivera, Luis; Lattanzi, Maria; Pedotti, Paola; Arora, Ashwani; Kieninger-Baum, Dorothee; Della Cioppa, Giovanni

2015-01-01

This study was designed to identify the optimal dose of an MF59-adjuvanted, monovalent, A/H1N1 influenza vaccine in healthy paediatric subjects. Subjects aged 3-8 years (n=194) and 9-17 years (n=160) were randomized to receive two primary doses of A/H1N1 vaccine containing either 3.75 μg antigen with half a standard dose of MF59 adjuvant, 7.5 μg antigen with a full dose of MF59, or (children 3-8 years only), a non-adjuvanted 15 μg formulation. A booster dose of MF59-adjuvanted seasonal influenza vaccine including homologous A/H1N1 strain was given one year after priming. Immunogenicity was assessed by haemagglutination inhibition (HI) and microneutralization assays. Vaccine safety was assessed throughout the study (up to 18 months). A single priming dose of either MF59-adjuvanted formulation was sufficient to meet the European licensure criteria for pandemic influenza vaccines (HI titres ≥1:40>70%; seroconversion>40%; and GMR>2.5). Two non-adjuvanted vaccine doses were required to meet the same licensure criteria. After first and second doses, percentage of subjects with HI titres ≥1:40 were between 97% and 100% in the adjuvanted vaccine groups compared with 68% and 91% in the non-adjuvanted group, respectively. Postvaccination seroconversion rates ranged from 91% to 98% in adjuvanted groups and were 68% (first dose) and 98% (second dose) in the non-adjuvanted group. HI titres ≥1:330 after primary doses were achieved in 69% to 90% in adjuvanted groups compared with 41% in the non-adjuvanted group. Long-term antibody persistence after priming and a robust antibody response to booster immunization were observed in all vaccination groups. All A/H1N1 vaccine formulations were generally well tolerated. No vaccine-related serious adverse events occurred, and no subjects were withdrawn from the study due to an adverse event. An MF59-adjuvanted influenza vaccine containing 3.75 μg of A/H1N1 antigen was well tolerated and sufficiently immunogenic to meet all the

Levels of DDT and its metabolites in placenta, maternal and cord blood and their potential influence on neonatal anthropometric measures

Energy Technology Data Exchange (ETDEWEB)

Al-Saleh, Iman, E-mail: iman@kfshrc.edu.sa [Environmental Health Section, Biological and Medical Research Department, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh (Saudi Arabia); Al-Doush, Inaam; Alsabbaheen, Ammar [Environmental Health Section, Biological and Medical Research Department, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh (Saudi Arabia); Mohamed, Gamal El Din [Biostatistics, Epidemiology and Scientific Computing Department, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh (Saudi Arabia); Rabbah, Abdullah [Department of Pediatrics, King Khalid Hospital, Al-Kharj (Saudi Arabia)

2012-02-01

Previous studies of in utero exposure to dichlorodiphenyltrichloroethane (DDT) have shown mixed results for the harmful effects on fetal growth and development. This cross-sectional study was designed to: (1) examine the extent of DDT exposure in 1578 women, aged 28.5 {+-} 6.0 who delivered between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; and (2) assess its influence on neonatal anthropometric measurement of newly born babies. DDT and its metabolites, namely 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p Prime -DDE), 1,1-dichloro-2,2-bis (p-chlorophenyl) ethane (p,p Prime -DDD) and 1,1,1-trichloro-2,2 Prime bis (p-chlorophenyl) ethane (p,p Prime -DDT) were measured in cord and maternal serum as well as placenta by Gas Chromatography coupled with an Electron Capture Detector (GC/ECD). p,p Prime -DDE was detected in 28.3% of cord and 54.4% of maternal serum, reflecting past exposure, whereas the p,p Prime -DDT was only found in 0.46% cord and 1.2% maternal samples. As expected the p,p Prime -DDE cord levels (0.197 {+-} 0.961 {mu}g/L) were 2.8 times lower than the maternal levels (0.551 {+-} 1.778 {mu}g/L), and both were significantly correlated (r = 0.517) suggesting its transplacental transfer. The picture was different in placental tissues. p,p Prime -DDE and p,p Prime -DDT were detected in 84% and 99% of placental tissues, with the highest p,p Prime -DDT in placental tissues (29.62 {+-} 158.282 Micro-Sign g/kg dry wt.) compare to p,p Prime -DDE (10.167 {+-} 18.851 {mu}g/kg dry wt.). In general, the presence of DDT metabolites in our participants indicates that these chemicals are still relevant despite the fact that they have been banned or restricted in the study area for many years. Our results support the view for an association between low in utero exposure to DDT and the anthropometric development of the fetus leading to a reduction in its head circumference, crown-heel length, birth weight and birth height. Since the reduction in these

Progress in Global Multicompartmental Modelling of DDT

Science.gov (United States)

Stemmler, I.; Lammel, G.

2009-04-01

Dichlorophenyltrichloroethane, DDT, and its major metabolite dichlorophenyldichloroethylene, DDE, are long-lived in the environment (persistent) and circulate since the 1950s. They accumulate along food chains, cause detrimental effects in marine and terrestrial wild life, and pose a hazard for human health. DDT was widely used as an insecticide in the past and is still in use in a number of tropical countries to combat vector borne diseases like malaria and typhus. It is a multicompartmental substance with only a small mass fraction residing in air. A global multicompartment chemistry transport model (MPI-MCTM; Semeena et al., 2006) is used to study the environmental distribution and fate of dichlorodiphenyltrichloroethane (DDT). For the first time a horizontally and vertically resolved global model was used to perform a long-term simulation of DDT and DDE. The model is based on general circulation models for the ocean (MPIOM; Marsland et al., 2003) and atmosphere (ECHAM5). In addition, an oceanic biogeochemistry model (HAMOCC5.1; Maier-Reimer et al., 2005 ) and a microphysical aerosol model (HAM; Stier et al., 2005 ) are included. Multicompartmental substances are cycling in atmosphere (3 phases), ocean (3 phases), top soil (3 phases), and vegetation surfaces. The model was run for 40 years forced with historical agricultural application data of 1950-1990. The model results show that the global environmental contamination started to decrease in air, soil and vegetation after the applications peaked in 1965-70. In some regions, however, the DDT mass had not yet reached a maximum in 1990 and was still accumulating mass until the end of the simulation. Modelled DDT and DDE concentrations in atmosphere, ocean and soil are evaluated by comparison with observational data. The evaluation of the model results indicate that degradation of DDE in air was underestimated. Also for DDT, the discrepancies between model results and observations are related to uncertainties of

MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

KAUST Repository

Villacorte, Loreen O.

2015-07-01

Pretreatment with microfiltration (MF) or ultrafiltration (UF) membranes has been proposed for seawater reverse osmosis (SWRO) plants to address operational issues associated with algal blooms. Here, we investigated the MF/UF rejection and fouling potential of algal organic matter (AOM) released by common species of bloom-forming marine (Alexandrium tamarense and Chaetoceros affinis) and freshwater (Microcystis sp.) algae. Batch culture monitoring of the three algal species illustrated varying growth pattern, cell concentration, AOM released and membrane fouling potential. The high membrane fouling potential of the cultures can be directly associated (R2>0.85) with AOM such as transparent exopolymer particle (TEP) while no apparent relationship with algal cell concentration was observed. The AOM comprised mainly biopolymers (e.g., polysaccharides and proteins) and low molecular weight organic compounds (e.g., humic-like substances). The former were largely rejected by MF/UF membranes while the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans-membrane pressure (δP) over time, characterised by pore blocking followed by cake filtration with enhanced compression as illustrated by an exponential progression of δP. © 2015 Elsevier B.V.

Hydrogen degradation of the 26H2MF alloy steel in H2SO4 and hydrocarbon environments

International Nuclear Information System (INIS)

Zielinski, A.; Swieczko-Zurek, B.; Michaliak, P.

2004-01-01

The Polish 26H2M alloy steel has been subjected to different heat treatment resulting in different microstructure and fracture appearance. The slow strain rate tests have been made on smooth round specimens in diluted sulphuric acid, boiler fuel and used mineral machine oil. The 26H2MF steel has become relatively immune in neutral boiler fuel and mineral oil and been heavily suffered from hydrogen degradation in acidic environment. The results demonstrate that the 26H2MF steel is highly susceptible to hydrogen degradation but in absence of stress raisers the increased hydrogen absorption in hydrocarbons can cause only small loss of its plasticity. (author) >>>

Effect of aerobic exercise intervention on DDT degradation and oxidative stress in rats

OpenAIRE

Li, Kefeng; Zhu, Xiaohua; Wang, Yuzhan; Zheng, Shuqian; Dong, Guijun

2017-01-01

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress. Main methods: Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise trea...

Ergonomic assessment of drivers in MF285 and MF399 tractors during clutching using algometer

Directory of Open Access Journals (Sweden)

Hossein Fallahi

2016-03-01

The results showed that the clutching forces for MF285 and MF399 tractors were 340 N and 290 N, respectively. The knee angle of the drivers of the two tractors was statistically different at the one percent level of significance. The reduction of pain threshold after 30 and 60 s clutching and also 60 s rest after clutching in MF285 tractor, for all three muscles, were more than those of MF399 tractor. The impact of clutching on the average decreases of pain threshold, for all drivers and all clutching periods, during and after clutching, in the Quadratus lumborum muscle was more than the other two muscles, in both tractors. In order to reduce the clutching force for MF285 tractor some modifications is suggested. In this regard the force transfer joint between the pedal and the clutch release linkage may be replaced with one made of cast iron.

The amphiphilic peptide adenoregulin enhances agonist binding to A1-adenosine receptors and [35S]GTP gamma S to brain membranes.

Science.gov (United States)

Moni, R W; Romero, F S; Daly, J W

1995-08-01

1. Adenoregulin is an amphilic peptide isolated from skin mucus of the tree frog, Phyllomedusa bicolor. Synthetic adenoregulin enhanced the binding of agonists to several G-protein-coupled receptors in rat brain membranes. 2. The maximal enhancement of agonist binding, and in parentheses, the concentration of adenoregulin affording maximal enhancement were as follows: 60% (20 microM) for A1-adenosine receptors, 30% (100 microM) for A2a-adenosine receptors, 20% (2 microM) for alpha 2-adrenergic receptors, and 30% (10 microM) for 5HT1A receptors. High affinity agonist binding for A1-, alpha 2-, and 5HT1A-receptors was virtually abolished by GTP gamma S in the presence of adenoregulin, but was only partially abolished in its absence. Magnesium ions increased the binding of agonists to receptors and reduced the enhancement elicited by adenoregulin. 3. The effect of adenoregulin on binding of N6-cyclohexyladenosine ([3H]CHA) to A1-receptors was relatively slow and was irreversible. Adenoregulin increased the Bmax value for [3H]CHA binding sites, and the proportion of high affinity states, and slowed the rate of [3H]CHA dissociation. Binding of the A1-selective antagonist, [3H]DPCPX, was maximally enhanced by only 13% at 2 microM adenoregulin. Basal and A1-adenosine receptor-stimulated binding of [35S]GTP gamma S were maximally enhanced 45% and 23%, respectively, by 50 microM adenoregulin. In CHAPS-solubilized membranes from rat cortex, the binding of both [3H]CHA and [3H]DPCPX were enhanced by adenoregulin. Binding of [3H]CHA to membranes from DDT1 MF-2 cells was maximally enhanced 17% at 20 microM adenoregulin. In intact DDT1 MF-2 cells, 20 microM adenoregulin did not potentiate the inhibition of cyclic AMP accumulation mediated via the adenosine A1 receptor. 4. It is proposed that adenoregulin enhances agonist binding through a mechanism involving enhancement of guanyl nucleotide exchange at G-proteins, resulting in a conversion of receptors into a high affinity state

Biorremediación de suelo contaminado con pesticidas: caso DDT

Directory of Open Access Journals (Sweden)

Bibiana Betancur Corredor

2013-12-01

Full Text Available El 1,1,1-tricloro-2,2'bis(p-clorofeniletano (DDT ha sido usado desde la segunda guerra mundial para controlar enfermedades transmitidas por insectos en humanos y animales domésticos. El uso de estos insecticidas organoclorados se ha prohibido en la mayoría de los países, debido a su persistencia en el ambiente, susceptibilidad de biomagnificación y potencial toxicidad a animales superiores. La biorremediación involucra el uso de microorganismos para degradar contaminantes orgánicos presentes en el ambiente, transformándolos en compuestos más simples y de menor peligrosidad, inclusive inocuos. Esta estrategia de descontaminación tiene bajos costos, una amplia aceptación pública y puede llevarse a cabo en el sitio. Comparado con otros métodos, la biorremediación es una forma más promisoria y menos costosa de eliminar los contaminantes presentes en suelos y agua. En suelo los compuestos bifenilos clorados como el DDT, pueden ser parcialmente biodegradados por un grupo de bacterias aerobias que cometabolizan el contaminante. La biodisponibilidad de los contaminantes puede ser mejorada, tratando los suelos en presencia de agentes movilizadores del contaminante como los surfactantes. En esta revisión se discuten las diferentes estrategias de biorremediación de suelo contaminado con DDT, incluyendo mecanismos y rutas de degradación. Se describe la aplicación de estas técnicas en suelo contaminado y se discute cuál es la mejor estrategia para remediación de DDT. 

The sphingosine 1-phosphate receptor S1P(2) triggers hepatic wound healing

NARCIS (Netherlands)

Serriere-Lanneau, Valerie; Teixeira-Clerc, Fatima; Li, Liying; Schippers, Marlies; de Wries, Willie; Julien, Boris; Tran-Van-Nhieu, Jeanne; Manin, Sylvie; Poelstra, Klaas; Chun, Jerold; Carpentier, Stephane; Levade, Thierry; Mallat, Ariane; Lotersztajn, Sophie

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid produced by sphingosine kinase (SphK1 and 2). We previously showed that S1P receptors (S1P(1), S1P(2), and S1P(3)) are expressed in hepatic myofibroblasts (hMF), a population of cells that triggers matrix remodeling during liver injury. Here

Analysis of CTCL cell lines reveals important differences between mycosis fungoides/Sézary syndrome vs. HTLV-1+ leukemic cell lines

DEFF Research Database (Denmark)

Netchiporouk, Elena; Gantchev, Jennifer; Tsang, Matthew

2017-01-01

HTLV-1 is estimated to affect ~20 million people worldwide and in ~5% of carriers it produces Adult T-Cell Leukemia/Lymphoma (ATLL), which can often masquerade and present with classic erythematous pruritic patches and plaques that are typically seen in Mycosis Fungoides (MF) and Sézary Syndrome...... (SS), the most recognized variants of Cutaneous T-Cell Lymphomas (CTCL). For many years the role of HTLV- 1 in the pathogenesis of MF/SS has been hotly debated. In this study we analyzed CTCL vs. HTLV-1+ leukemic cells. We performed G-banding/spectral karyotyping, extensive gene expression analysis......, TP53 sequencing in the 11 patient-derived HTLV- 1+ (MJ and Hut102) vs. HTLV-1- (Myla, Mac2a, PB2B, HH, H9, Hut78, SZ4, Sez4 and SeAx) CTCL cell lines. We further tested drug sensitivities to commonly used CTCL therapies and studied the ability of these cells to produce subcutaneous xenograft tumors...

Effects of dressing and cooking on DDT concentrations in certain fish from Lake Michigan

Science.gov (United States)

Reinert, Robert E.; Stewart, Donald; Seagran, Harry L.

1972-01-01

Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.

Expression of Hormonal Carcinogenesis Genes and Related Regulatory microRNAs in Uterus and Ovaries of DDT-Treated Female Rats.

Science.gov (United States)

Kalinina, T S; Kononchuk, V V; Gulyaeva, L F

2017-10-01

The insecticide dichlorodiphenyltrichloroethane (DDT) is a nonmutagenic xenobiotic compound able to exert estrogen-like effects resulting in activation of estrogen receptor-α (ERα) followed by changed expression of its downstream target genes. In addition, studies performed over recent years suggest that DDT may also influence expression of microRNAs. However, an impact of DDT on expression of ER, microRNAs, and related target genes has not been fully elucidated. Here, using real-time PCR, we assessed changes in expression of key genes involved in hormonal carcinogenesis as well as potentially related regulatory oncogenic/tumor suppressor microRNAs and their target genes in the uterus and ovaries of female Wistar rats during single and chronic multiple-dose DDT exposure. We found that applying DDT results in altered expression of microRNAs-221, -222, -205, -126a, and -429, their target genes (Pten, Dicer1), as well as genes involved in hormonal carcinogenesis (Esr1, Pgr, Ccnd1, Cyp19a1). Notably, Cyp19a1 expression seems to be also regulated by microRNAs-221, -222, and -205. The data suggest that epigenetic effects induced by DDT as a potential carcinogen may be based on at least two mechanisms: (i) activation of ERα followed by altered expression of the target genes encoding receptor Pgr and Ccnd1 as well as impaired expression of Cyp19a1, affecting, thereby, cell hormone balance; and (ii) changed expression of microRNAs resulting in impaired expression of related target genes including reduced level of Cyp19a1 mRNA.

Safety and immunogenicity of a recombinant parvovirus B19 vaccine formulated with MF59C.1.

Science.gov (United States)

Ballou, W Ripley; Reed, Jennifer L; Noble, William; Young, Neal S; Koenig, Scott

2003-02-15

A recombinant human parvovirus B19 vaccine (MEDI-491; MedImmune) composed of the VP1 and VP2 capsid proteins and formulated with MF59C.1 adjuvant was evaluated in a randomized, double-blind, phase 1 trial. Parvovirus B19-seronegative adults (n=24) received either 2.5 or 25 microg MEDI-491 at 0, 1, and 6 months. MEDI-491 was safe and immunogenic. All volunteers developed neutralizing antibody titers that peaked after the third immunization and were sustained through study day 364.

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

Energy Technology Data Exchange (ETDEWEB)

Kazantseva, Yuliya A.; Yarushkin, Andrei A. [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Pustylnyak, Vladimir O., E-mail: pustylnyak@ngs.ru [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Novosibirsk State University, Novosibirsk, Pirogova str., 2, 630090 (Russian Federation)

2013-09-01

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

International Nuclear Information System (INIS)

Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O.

2013-01-01

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

Exploration of different methods for measuring DDT exposure among malaria vector-control workers in Limpopo Province, South Africa

International Nuclear Information System (INIS)

Dalvie, M.A.; Myers, J.E.; Thompson, M.L.; Robins, T.G.; Omar, Shaheed; Riebow, John

2004-01-01

DDT compounds are used in many developing countries, including South Africa, for the control of malaria vectors. This study investigated biological exposures among workers in relation to job history. A cross-sectional study of 59 workers at the Malaria Control Centre (MCC) in Tzaneen, South Africa, was performed. Tests included a job history questionnaire and the measurement of serum o'p' and p'p' isomers of DDE, DDT, and DDD, corrected for serum total lipids. Forty-seven (80%) workers donated a blood sample for the determination of serum DDT. The mean number of years worked at the MCC (malaria years) was 15.8±7.8 years and the mean serum DDT was 94.3±57.1 μg/g of lipid. There were no significant associations between short-to-medium-term serum DDT exposure measures (o'p'-DDE and o'p' and p'p' isomers of DDD and DDT) and malaria years. The long-term exposure measure, p'p'-DDE, was significantly associated with malaria years (β-circumflex=3.0±1.2 μg/g lipid/year; P=0.001; n=47; adjusted for age), but only 27% variance of p'p'-DDE was explained. Blood total DDT uncorrected for lipid content was strongly related to corrected levels (β-circumflex=0.74±0.48, P=0.00, R 2 =0.77), but uncorrected p'p'-DDE had a weaker association (β-circumflex=0.0024±0.0013, P=0.074; R 2 =0.53) with malaria years than did corrected levels (β-circumflex=0.042±0.017; P=0.016; R 2 =0.56). The results show that serum DDT levels for malaria vector-control workers in South Africa with a long-term spraying history are high. Job history information on DDT exposures must be very detailed in order to provide valid estimates of exposure

The mechanism of action of MF59 - an innately attractive adjuvant formulation.

Science.gov (United States)

O'Hagan, D T; Ott, G S; De Gregorio, E; Seubert, A

2012-06-19

MF59 is a safe and effective vaccine adjuvant which was originally approved to be included in a licensed influenza vaccine to be used in the elderly in Europe in 1997. The MF59 adjuvanted influenza vaccine (Fluad™) is now licensed in more than 20 countries worldwide and more than 85 million doses have been administered. More recently the vaccine adjuvant has also been shown to be safe and effective in young children and resulted in a significant increase in influenza vaccine efficacy in a controlled clinical trial in Europe. Since the early days of its discovery we have explored the mechanism of action of MF59, using a variety of available techniques. In recent years we have explored more thoroughly the mechanism of action using new and more sophisticated techniques. It is remarkable how consistent the data has been, using a variety of different approaches both in several small animal models and also using human immune cells in vitro. Here we present a summary of all the work performed to date on the mechanism of action of MF59 and we present a unified theory based on the accumulated data of how it exerts its adjuvant effects. A key element of the mechanism of action appears to be the creation of a transient 'immunocompetent' local environment at the injection site, resulting in the recruitment of key immune cells, which are able to take up antigen and adjuvant and transport them to the local lymph nodes, where the immune response is induced. This recruitment appears to be triggered by the induction of a chemokine driven gradient by the impact of MF59 on local cells, which are activated to secrete further chemokines, which are recruitment factors for more immune cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

Czech Academy of Sciences Publication Activity Database

Pavlíková, N.; Smetana, P.; Halada, Petr; Kovář, J.

2015-01-01

Roč. 142, OCT 2015 (2015), s. 257-263 ISSN 0013-9351 Grant - others:OPPK(CZ) CZ.2.16/3.1.00/24023 Source of funding: O - operačné programy Keywords : Diabetes * DDT/E * Alpha-enolase Subject RIV: CE - Biochemistry Impact factor: 3.088, year: 2015

Methylferulate from Tamarix aucheriana inhibits growth and enhances chemosensitivity of human colorectal cancer cells: possible mechanism of action.

Science.gov (United States)

Abaza, Mohamed Salah I; Afzal, Mohammad; Al-Attiyah, Raja'a J; Guleri, Radhika

2016-10-01

Natural products are valuable sources for anticancer agents. In the present study, methylferulate (MF) was identified for the first time from Tamarix aucheriana. Spectral data were used for identification of MF. The potential of MF to control cell growth, cell cycle, apoptosis, generation of reactive oxygen species (ROS), cancer cell invasion, nuclear factor kappa B (NFkB) DNA-binding activity and proteasomal activities, as well as the enhancement of chemosensitivity in human colorectal cancer cells, were evaluated. The possible molecular mechanism of MF's therapeutic efficacy was also assessed. Column chromatography and spectral data were used for isolation and identification of MF. MTT, immunofluorescence, flow cytometry, in vitro invasion, fluoremetry, EIA and Real time qPCR were used to measure antiproliferative, chemo-sensitizing effects and other biochemical parameters. MF showed a dose-dependent anti-proliferative effect on colorectal cancer cells (IC 50  = 1.73 - 1.9 mM) with a nonsignificant cytotoxicity toward normal human fibroblast. Colony formation inhibition (P ≤ 0.001, 0.0001) confirmed the growth inhibition by MF. MF arrested cell cycle progression in the S and G2/M phases; induced apoptosis and ROS generation; and inhibited NF-kB DNA-binding activity, proteasomal activities and cell invasion in colorectal cancer cells. MF up-regulated cyclin-dependent kinase inhibitors (p19 INK4D , p21 WAF1/CIP1 , p27 KIP1 ), pro-apoptotic gene expression (Bax, Bad, Apaf1, Bid, Bim, Smac) and caspases (caspase 2, 3, 6, 7, 8, 9). Moreover, MF down-regulated cyclin-dependent kinases (Cdk1, Cdk2) and anti-apoptotic gene expression (c-IAP-1, c-IAP-2, Bcl2,FLIP). In addition, MF differentially potentiated the sensitivity of colorectal cancer cells to standard chemotherapeutic drugs. MF showed a multifaceted anti-proliferative and chemosensitizing effects. These results suggest the chemotherapeutic and co-adjuvant potential of MF.

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system.

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Ali, Imran; Alharbi, Omar M L; Alothman, Zeid A; Alwarthan, Abdulrahman

2018-01-01

Enantio-selective molecular dynamics of (±)-o,p-DDT uptake and degradation in water-sediment system is described. Both uptake and degradation processes of (-)-o,p-DDT were slightly higher than (+)-o,p-DDT enantiomer. The optimized parameters for uptake were 7.0μgL -1 concentration of o,p-DDT, 60min contact time, 5.0pH, 6.0gL -1 amount of reverine sediment and 25°C temperature. The maximum degradation of both (-)- and (+)-o,p-DDT was obtained with 16 days, 0.4μgL -1 concentration of o,p-DDT, pH 7 and 35°C temperature. Both uptake and degraded process followed first order rate reaction. Thermodynamic parameters indicated exothermic nature of uptake and degradation processes. Both uptake and degradation were slightly higher for (-)-enantiomer in comparison to (+)-enantiomer of o,p-DDT. It was concluded that both uptake and degradation processes are responsible for the removal of o,p-DDT from nature but uptake plays a crucial role. The percentage degradations of (-)- and (+)-o,p-DDT were 30.1 and 29.5, respectively. This study may be useful to manage o,p-DDT contamination of our earth's ecosystem. Copyright © 2017. Published by Elsevier Inc.

Prenatal DDT and DDE exposure and child IQ in the CHAMACOS cohort.

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Gaspar, Fraser W; Harley, Kim G; Kogut, Katherine; Chevrier, Jonathan; Mora, Ana Maria; Sjödin, Andreas; Eskenazi, Brenda

2015-12-01

Although banned in most countries, dichlorodiphenyl-trichloroethane (DDT) continues to be used for vector control in some malaria endemic areas. Previous findings from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort study found increased prenatal levels of DDT and its breakdown product dichlorodiphenyl-dichloroethylene (DDE) to be associated with altered neurodevelopment in children at 1 and 2years of age. In this study, we combined the measured maternal DDT/E concentrations during pregnancy obtained for the prospective birth cohort with predicted prenatal DDT and DDE levels estimated for a retrospective birth cohort. Using generalized estimating equation (GEE) and linear regression models, we evaluated the relationship of prenatal maternal DDT and DDE serum concentrations with children's cognition at ages 7 and 10.5years as assessed using the Full Scale Intelligence Quotient (IQ) and 4 subtest scores (Working Memory, Perceptual Reasoning, Verbal Comprehension, and Processing Speed) of the Wechsler Intelligence Scale for Children (WISC). In GEE analyses incorporating both age 7 and 10.5 scores (n=619), we found prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales (p-value>0.05). In linear regression analyses assessing each time point separately, prenatal DDT levels were inversely associated with Processing Speed at age 7years (n=316), but prenatal DDT and DDE levels were not associated with Full Scale IQ or any of the WISC subscales at age 10.5years (n=595). We found evidence for effect modification by sex. In girls, but not boys, prenatal DDE levels were inversely associated with Full Scale IQ and Processing Speed at age 7years. We conclude that prenatal DDT levels may be associated with delayed Processing Speed in children at age 7years and the relationship between prenatal DDE levels and children's cognitive development may be modified by sex, with girls being more adversely

Macrolactin F inhibits RANKL-mediated osteoclastogenesis by suppressing Akt, MAPK and NFATc1 pathways and promotes osteoblastogenesis through a BMP-2/smad/Akt/Runx2 signaling pathway.

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Li, Liang; Sapkota, Mahesh; Gao, Ming; Choi, Hyukjae; Soh, Yunjo

2017-11-15

The balance between bone formation and bone resorption is maintained by osteoblasts and osteoclasts. In the current study, macrolactin F (MF) was investigated for novel biological activity on the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis in primary bone marrow-derived macrophages (BMMs). We found that RANKL-induced osteoclast formation and differentiation from BMMs was significantly inhibited by MF in a dose-dependent manner without cytotoxicity. RANKL-induced F-actin ring formation and bone resorption activity in BMMs which was attenuated by MF. In addition, MF suppressed the expression of osteoclast-related genes, including c-myc, RANK, tartrate-resistant acid phosphatase (TRAP), nuclear factor of activated T cells c1 (NFATc1), cathepsin K and matrix metalloproteinase 9 (MMP9). Furthermore, the protein expression NFATc1, c-Fos, MMP9, cathepsin K and phosphorylation of Jun N-terminal kinase (JNK), p38 and Akt were also down-regulated by MF treatment. Interestingly, MF promoted pre-osteoblast cell differentiation on Alizarin Red-mineralization activity, alkaline phosphatase (ALP) activity, and the expression of osteoblastogenic markers including Runx2, Osterix, Smad4, ALP, type I collagen alpha 1 (Col1α), osteopontin (OPN), and osteocalcin (OCN) via activation of the BMP-2/smad/Akt/Runx2 pathway on MC3T3-E1. Taken together, these results indicate that MF may be useful as a therapeutic agent to enhance bone health and treat osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Bioavailability assessments following biochar and activated carbon amendment in DDT-contaminated soil.

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Denyes, Mackenzie J; Rutter, Allison; Zeeb, Barbara A

2016-02-01

The effects of 2.8% w/w granulated activated carbon (GAC) and two types of biochar (Burt's and BlueLeaf) on DDT bioavailability in soil (39 μg/g) were investigated using invertebrates (Eisenia fetida), plants (Cucurbita pepo spp. pepo) and a polyoxymethylene (POM) passive sampler method. Biochar significantly reduced DDT accumulation in E. fetida (49%) and showed no detrimental effects to invertebrate health. In contrast, addition of GAC caused significant toxic effects (invertebrate avoidance and decreased weight) and did not significantly reduce the accumulation of DDT into invertebrate tissue. None of the carbon amendments reduced plant uptake of DDT. Bioaccumulation of 4,4'DDT and 4,4'-DDE in plants (C. pepo spp. pepo) and invertebrates (E. fetida) was assessed using bioaccumulation factors (BAFs) and compared to predicted bioavailability using the freely-dissolved porewater obtained from a polyoxymethylene (POM) equilibrium biomimetic method. The bioavailable fraction predicted by the POM samplers correlated well with measured invertebrate uptake (DDT soil contamination levels and the inclusion of field data from a 2.5 μg/g DDT-contaminated site found that these plants exhibit a concentration threshold effect at [DDT](soil) > 10 μg/g. The results of these studies illustrate the importance of including plants in bioavailability studies as the use of carbon materials for in situ contaminant sorption moves from predominantly sediment to soil remediation technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bisphenol A, Dichlorodiphenyltrichloroethane (DDT) and Vinclozolin Affect ex-vivo Uterine Contraction in Rats via Uterotonin (Prostaglandin F2α, Acetylcholine and Oxytocin) Related Pathways.

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Salleh, Naguib; Giribabu, Nelli; Feng, Angeline Oh Mei; Myint, Kyaimon

2015-01-01

Bisphenol-A (BPA), dichrolodiphenyltrichloroethane (DDT) and vinclozolin were found able to induce abnormal uterine contraction. The mechanisms involved remains unclear. We hypothesized that the effect of these compounds were mediated via the uterotonin pathways. Therefore, in this study, effects of BPA, vinclozolin and DDT-only and in combination with uterotonins (PGF-2α, acetylcholine and oxytocin) on the force and pattern of uterine contraction were observed. Uteri were harvested from intact adult female rats 24 hours after a single injection (1 mg/kg/b.w) of estrogen to synchronize their oestrous cycle. The uterine horns were subjected for ex-vivo contraction studies in an organ bath connected to Powerlab data acquisition system. Different doses of BPA, vinclozolin and DDT were added into the bathing solution and changes in the pattern and strength of uterine contraction were recorded. Further, increasing doses of uterotonins were concomitantly administered with these compounds and changes in the force and pattern of contraction were observed. In the absence of uterotonins, uterine contractile force decreased with increasing doses of BPA and DDT. However, vinclozolin induced sharp increase in the contractile forces which then gradually decrease. Administration of BPA, DDT and vinclozolin alone reduced the force of uterine contraction following stimulation of contraction by uterotonins. However, BPA, vinclozolin or DDT effects were relieved upon co-administration with uterotonins at increasing doses. The antagonizing effect of uterotonins on BPA, vinclozolin and DDT actions could explain the mechanism underlying the adverse effect of these compounds on uterine contraction.

Electrical properties and structure of glasses in the Ba(PO3)2-MF2 systems, where M = Mg, Ca, Sr, Ba

International Nuclear Information System (INIS)

Sokolov, I.A.; Tarlakov, Yu.P.; Murin, I.V.; Pronkin, A.A.

2000-01-01

Using the methods of conductometry and IR spectroscopy the concentrational dependences of electric conductivity are studied, the nature of current carriers is determined, the concentrational dependence of transfer numbers is ascertained and structural changes in glasses of the system Ba(PO 3 ) 2 -MF 2 (M = Mg, Ca, Sr, Ba), depending on MF 2 content, are considered. It is shown that F - ions take part in electric current transfer. Influence of crystallochemical nature of alkaline-earth cations on physicochemical properties and structure of the glasses studied is analyzed [ru

Metabolic and Target-Site Mechanisms Combine to Confer Strong DDT Resistance in Anopheles gambiae

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Mitchell, Sara N.; Rigden, Daniel J.; Dowd, Andrew J.; Lu, Fang; Wilding, Craig S.; Weetman, David; Dadzie, Samuel; Jenkins, Adam M.; Regna, Kimberly; Boko, Pelagie; Djogbenou, Luc; Muskavitch, Marc A. T.; Ranson, Hilary; Paine, Mark J. I.; Mayans, Olga; Donnelly, Martin J.

2014-01-01

The development of resistance to insecticides has become a classic exemplar of evolution occurring within human time scales. In this study we demonstrate how resistance to DDT in the major African malaria vector Anopheles gambiae is a result of both target-site resistance mechanisms that have introgressed between incipient species (the M- and S-molecular forms) and allelic variants in a DDT-detoxifying enzyme. Sequencing of the detoxification enzyme, Gste2, from DDT resistant and susceptible strains of An. gambiae, revealed a non-synonymous polymorphism (I114T), proximal to the DDT binding domain, which segregated with strain phenotype. Recombinant protein expression and DDT metabolism analysis revealed that the proteins from the susceptible strain lost activity at higher DDT concentrations, characteristic of substrate inhibition. The effect of I114T on GSTE2 protein structure was explored through X-ray crystallography. The amino acid exchange in the DDT-resistant strain introduced a hydroxyl group nearby the hydrophobic DDT-binding region. The exchange does not result in structural alterations but is predicted to facilitate local dynamics and enzyme activity. Expression of both wild-type and 114T alleles the allele in Drosophila conferred an increase in DDT tolerance. The 114T mutation was significantly associated with DDT resistance in wild caught M-form populations and acts in concert with target-site mutations in the voltage gated sodium channel (Vgsc-1575Y and Vgsc-1014F) to confer extreme levels of DDT resistance in wild caught An. gambiae. PMID:24675797

Identification and expression analysis of BoMF25, a novel polygalacturonase gene involved in pollen development of Brassica oleracea.

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Lyu, Meiling; Liang, Ying; Yu, Youjian; Ma, Zhiming; Song, Limin; Yue, Xiaoyan; Cao, Jiashu

2015-06-01

BoMF25 acts on pollen wall. Polygalacturonase (PG) is a pectin-digesting enzyme involved in numerous plant developmental processes and is described to be of critical importance for pollen wall development. In the present study, a PG gene, BoMF25, was isolated from Brassica oleracea. BoMF25 is the homologous gene of At4g35670, a PG gene in Arabidopsis thaliana with a high expression level at the tricellular pollen stage. Collinear analysis revealed that the orthologous gene of BoMF25 in Brassica campestris (syn. B. rapa) genome was probably lost because of genome deletion and reshuffling. Sequence analysis indicated that BoMF25 contained four classical conserved domains (I, II, III, and IV) of PG protein. Homology and phylogenetic analyses showed that BoMF25 was clustered in Clade F. The putative promoter sequence, containing classical cis-acting elements and pollen-specific motifs, could drive green fluorescence protein expression in onion epidermal cells. Quantitative RT-PCR analysis suggested that BoMF25 was mainly expressed in the anther at the late stage of pollen development. In situ hybridization analysis also indicated that the strong and specific expression signal of BoMF25 existed in pollen grains at the mature pollen stage. Subcellular localization showed that the fluorescence signal was observed in the cell wall of onion epidermal cells, which suggested that BoMF25 may be a secreted protein localized in the pollen wall.

p,p'-DDE Induces Gonadal Intersex in Japanese Medaka (Oryzias latipes) at Environmentally Relevant Concentrations: Comparison with o,p'-DDT.

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Sun, Jianxian; Wang, Chen; Peng, Hui; Zheng, Guomao; Zhang, Shiyi; Hu, Jianying

2016-01-05

Previous studies have reported high body burdens of dichlorodiphenyltrichloroethane (DDT) and its metabolites in wild fishes worldwide. This study evaluated the adverse effects of 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) and o,p'-DDT on gonadal development and reproduction by exposing transgenic Japanese medaka (Oryzias latipes) from hatch for 100 days. While both p,p'-DDE and o,p'-DDT induced intersex in male medaka, the lowest observable effective concentration (LOEC) of o,p'-DDT was 57.7 ng/g ww, about 5-fold lower than that (272 ng/g ww) of p,p'-DDE. Since LOECs of both chemicals were comparable to the body concentrations in wild fish, DDT contamination would likely contribute to the occurrence of intersex observed in wild fish. Exposure to o,p'-DDT resulted in much higher expression of vitellogenin in liver of males than p,p'-DDE, accordant with the higher potency of o,p'-DDT than p,p'-DDE to induce intersex. This phenomenon could be partly explained by the significantly elevated levels of 17β-estradiol in plasma of males exposed to o,p'-DDT, in addition to its estrogenic activity via the estrogen receptor. Significantly lower fertilization (p = 0.006) and hatchability (p = 0.019) were observed in the 13 intersex males. This study for the first time demonstrated the induction of intersex and reproductive effects of p,p'-DDE and o,p'-DDT at environmentally relevant concentrations.

Synergistic effect of DDT and its metabolites in lipopolysaccharide-mediated TNF-α production is inhibited by progesterone in peripheral blood mononuclear cells.

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Dominguez-Lopez, Pablo; Diaz-Cueto, Laura; Aguilar-Rojas, Arturo; Arechavaleta-Velasco, Fabian

2017-07-01

Increased TNF-α levels have been associated with adverse pregnancy outcomes. Lipopolysaccharide (LPS), 1,1,1-trichloro-2,2-bis-(chlorophenyl)ethane (DDT), 1,1-bis-(chlorophenyl)-2,2-dichloroethene (DDE), and 1,1-dichloro-2,2-bis(chlorophenyl)ethane (DDD) induce TNF-α release in peripheral blood mononuclear cells (PBMC). Conversely, progesterone (P4) inhibits TNF-α secretion. Pregnant women in malaria endemic areas may be co-exposure to these compounds. Thus, this study was to investigate the synergistic effect of LPS and these pesticides in PBMC and to assess P4 influence on this synergy. Cultured PBMC were exposed to each pesticide in the presence of LPS, P4, or their combination. TNF-α was measured by ELISA. All pesticides enhanced TNF-α synthesis in PBMC. Co-exposure with LPS synergizes TNF-α production, which is blocked by progesterone. These results indicate that these organochlorines act synergistically with LPS to induce TNF-α secretion in PBMC. This effect is blocked by P4. © 2017 Wiley Periodicals, Inc.

Embryogenic potential and the expression of arabinogalactanproteins (AGPs in embryogenic cell aggregates of Coffea arabica cv. Caturra rojo under influence of CO2

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Raúl Barbón

2002-07-01

Full Text Available The establishment and optimization of regeneration systems via somatic embryogenesis has centered traditionally on the study of the culture medium components, with little attention to other factors of the in vitro environment like the composition of the gaseous atmosphere. This work was realized with the aim to determine the embryogenic potential and the expression of arabinogalactanproteins (AGPs in embryogenic cell aggregates of Coffea arabica cv. Caturra Rojo under influence of carbon dioxide (CO2. Concentrations of 2.5% and 5.0% of CO2 stimulated a greater formation of somatic embryos (307 ES/50mgMF and 277 ES/50mgMF respectively in semisolid culture medium with better results to the controls with passive interchange and forced ventilation (195 ES/50mgMF and 107 ES/50mgMF whereas a concentration of 10.0% of CO2 inhibited the process of somatic embryogenesis (95 ES/50mgMF. In cell suspensions the formation of somatic embryos was greater with a concentration of 2.5% of CO2 (130x103 ES.l-1 in comparison with 5.0% and 10.0% of CO2 (116x103 ESl-1 and 15x103 ES.l-1 and the controls with passive interchange and forced ventilation. With a concentration of 2.5% CO2 there was a greater synthesis of Arabinogalactanproteins (AGPs at the cellular level (0.068 mg.gMF-1 and the excretion in the culture medium (2.10 mg.l-1, which coincided with the highest values of production of somatic embryos. Key Words: embryogenic cell suspensions, in vitro environment, molecular markers, somatic embryo, somatic embryogenesis

In Utero DDT and DDE Exposure and Obesity Status of 7-Year-Old Mexican-American Children in the CHAMACOS Cohort

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Schall, Raul Aguilar; Harley, Kim G.; Bradman, Asa; Barr, Dana; Eskenazi, Brenda

2013-01-01

Background: In utero exposure to endocrine disrupting compounds including dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) has been hypothesized to increase risk of obesity later in life. Objectives: The Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study is a longitudinal birth cohort of low-income Latinas living in a California agricultural community. We examined the relation of in utero DDT and DDE exposure to child obesity at 7 years of age. We also examined the trend with age (2, 3.5, 5, and 7 years) in the exposure–obesity relation. Methods: We included 270 children with o,p´-DDT, p,p´-DDT, and p,p´-DDE concentrations measured in maternal serum during pregnancy (nanograms per gram lipid) and complete 7-year follow-up data including weight (kilograms) and height (centimeters). Body mass index (BMI; kilograms per meter squared) was calculated and obesity was defined as ≥ 95th percentile on the sex-specific BMI-for-age Centers for Disease Control and Prevention 2000 growth charts. Results: At 7 years, 96 (35.6%) children were obese. A 10-fold increase in o,p´-DDT, p,p´-DDT, or p,p´-DDE, was nonsignificantly associated with increased odds (OR) of obesity [o,p´-DDT adjusted (adj-) OR = 1.17, 95% CI: 0.75, 1.82; p,p´-DDT adj-OR = 1.19, 95% CI: 0.81, 1.74; p,p´-DDE adj-OR = 1.22, 95% CI: 0.72, 2.06]. With increasing age at follow-up, we observed a significant trend toward a positive association between DDT and DDE exposure and odds of obesity. Conclusion: We did not find a significant positive relation between in utero DDT and DDE exposure and obesity status of 7-year-old children. However, given the observed trend with age, continued follow-up will be informative. PMID:23512307

Novel method for determining DDT in vapour and particulate phases within contaminated indoor air in a malaria area of South Africa

International Nuclear Information System (INIS)

Naudé, Yvette; Rohwer, Egmont R.

2012-01-01

Highlights: ► We present a novel denuder for the determination of DDT in contaminated indoor air. ► Single step concentration of vapour phase on PDMS, particulate phase on filter. ► Solvent-free green technique, sample extraction not required. ► Ratios of airborne p,p′-DDD/p,p′-DDT and of o,p′-DDT/p,p′-DDT are unusual. ► Insecticidal efficacy of technical DDT may be compromised. - Abstract: The organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control in certain areas of South Africa. The strict Stockholm Convention on Persistent Organic Pollutants (POPs) allows spraying on the inside of traditional dwellings with DDT. In rural villages contaminated dust presents an additional pathway for exposure to DDT. We present a new method for the determination of DDT in indoor air where separate vapour and particulate samples are collected in a single step with a denuder configuration of a multi-channel open tubular silicone rubber (polydimethylsiloxane (PDMS)) trap combined with a micro quartz fibre filter. The multi-channel PDMS trap section of the denuder concentrates vapour phase insecticide whereas particle associated insecticide is transferred downstream where it is collected on a micro-fibre filter followed by a second multi-channel PDMS trap to capture the blow-off from the filter. The multi-channel PDMS trap and filter combination are designed to fit a commercial thermal desorber for direct introduction of samples into a GC–MS. The technique is solvent-free. Analyte extraction and sample clean-up is not required. Two fractions, vapour phase and particulate phase p,p′-DDT, o,p′-DDT; p,p′-DDD, o,p′-DDD; p,p′-DDE and o,p′-DDE in 4 L contaminated indoor air, were each quantitatively analysed by GC–MS using isotopically labelled ring substituted 13 C 12 –p,p′-DDT as an internal standard. Limits of detection were 0.07–0.35 ng m −3 for p,p′-DDT, o,p′-DDT, p

Organochlorine insecticides DDT and chlordane in relation to survival following breast cancer.

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Parada, Humberto; Wolff, Mary S; Engel, Lawrence S; White, Alexandra J; Eng, Sybil M; Cleveland, Rebecca J; Khankari, Nikhil K; Teitelbaum, Susan L; Neugut, Alfred I; Gammon, Marilie D

2016-02-01

Organochlorine insecticides have been studied extensively in relation to breast cancer incidence, and results from two meta-analyses have been null for late-life residues, possibly due to measurement error. Whether these compounds influence survival remains to be fully explored. We examined associations between organochlorine insecticides [p,p'-DDT (dichlorodiphenyltrichloroethane), its primary metabolite, p,p'-DDE, and chlordane] assessed shortly after diagnosis and survival among women with breast cancer. A population-based sample of women diagnosed with a first primary invasive or in situ breast cancer in 1996-1997 and with available organochlorine blood measures (n = 633) were followed for vital status through 2011. After follow-up of 5 and 15 years, we identified 55 and 189 deaths, of which 36 and 74, respectively, were breast cancer-related. Using Cox regression models, we estimated the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for lipid-adjusted organochlorine concentrations with all-cause and breast cancer-specific mortality. At 5 years after diagnosis, the highest tertile of DDT concentration was associated with all-cause (HR = 2.19; 95% CI: 1.02, 4.67) and breast cancer-specific (HR = 2.72; 95% CI: 1.04, 7.13) mortality. At 15 years, middle tertile concentrations of DDT (HR = 1.42; 95% CI 0.99, 2.06) and chlordane (HR = 1.42; 95% CI: 0.94, 2.12) were modestly associated with all-cause and breast cancer-specific mortality. Third tertile DDE concentrations were inversely associated with 15-year all-cause mortality (HR = 0.66; 95% CI: 0.44, 0.99). This is the first population-based study in the United States to show that DDT may adversely impact survival following breast cancer diagnosis. Further studies are warranted given the high breast cancer burden and the ubiquity of these chemicals. © 2015 UICC.

gamma-Glutamyl transpeptidase overexpression increases metastatic growth of B16 melanoma cells in the mouse liver.

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Obrador, Elena; Carretero, Julian; Ortega, Angel; Medina, Ignacio; Rodilla, Vicente; Pellicer, José A; Estrela, José M

2002-01-01

B16 melanoma (B16M) cells with high glutathione (GSH) content show rapid proliferation in vitro and high metastatic activity in the liver in vivo. gamma-Glutamyl transpeptidase (GGT)-mediated extracellular GSH cleavage and intracellular GSH synthesis were studied in vitro in B16M cells with high (F10) and low (F1) metastatic potential. GGT activity was modified by transfection with the human GGT gene (B16MF1/Tet-GGT cells) or by acivicin-induced inhibition. B16MF1/Tet-GGT and B16MF10 cells exhibited higher GSH content (35 +/- 6 and 40 +/- 5 nmol/10(6) cells, respectively) and GGT activity (89 +/- 9 and 37 +/- 7 mU/10(6) cells, respectively) as compared (P <.05) with B16MF1 cells (10 +/- 3 nmol GSH and 4 mU GGT/10(6) cells). Metastasis (number of foci/100 mm(3) of liver) increased in B16MF1 cells pretreated with GSH ester ( approximately 3-fold, P <.01), and decreased in B16MF1/Tet-GGT and B16MF10 cells pretreated with the GSH synthesis inhibitor L-buthionine (S,R)-sulphoximine ( approximately 5-fold and 2-fold, respectively, P <.01). Liver, kidney, brain, lung, and erythrocyte GSH content in B16MF1/Tet-GGT- or B16MF10-bearing mice decreased as compared with B16MF1- and non-tumor-bearing mice. Organic anion transporting polypeptide 1-independent sinusoidal GSH efflux from hepatocytes increased in B16MF1/Tet-GGT- or B16MF10-bearing mice ( approximately 2-fold, P <.01) as compared with non-tumor-bearing mice. Our results indicate that tumor GGT activity and an intertissue flow of GSH can regulate GSH content of melanoma cells and their metastatic growth in the liver.

DDE, DDT + dieldrin: Residues in American kestrels and relations to reproduction

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Wiemeyer, Stanley N.; Porter, Ron; Hensler, G.L.; Maestrelli, J.R.

1986-01-01

Captive American kestrels (Falco sparverius) given long-term dietary dosages of DDT and dieldrin in combination, at low and high rates, were compared with controls to determine the effects of the toxicants on reproductive success and eggshell thickness. Additional kestrels were dosed with DDE to determine its effect on shell thickness. Tissues of birds that died or were sacrificed, and eggs, were analyzed for DDE, DDD, DDT, and dieldrin. Eight paired birds, mostly males, given a high dosage of DDT + dieldrin died of dieldrin poisoning. Three periods of heavy mortality involving only dosed birds, which occurred in summer 1966, fall 1967, and spring 1968, followed temperature declines and other stress factors. Organochlorine concentrations in tissues of sacrificed birds and eggs in all units of the DDT + dieldrin study were significantly different among treatments. Residue concentrations in tissues of birds on high dosage of DDT + dieldrin were about 3 times higher than those on low dosage, a difference similar to the relative magnitude of the dose rates. Concentrations of some toxicants, especially DDE, were significantly higher in tissues of males than females, although these differences were difficult to interpret because males generally were sacrificed later than females. Concentrations in tissues and eggs of dosed yearlings, placed on clean food 7 to 9 weeks before pairing, were often significantly lower than in those yearlings that remained on dosage. Concentrations of each toxicant were usually highly correlated (r > 0.85) among tissues, especially for DDE and dieldrin. Organochlorine concentrations in brains and eggs could be predicted from concentrations in carcasses. DDE and dieldrin concentrations in eggs were about one-half those in carcasses, DDD about one-seventh, and DDT 1.5 to 2 times higher in eggs than carcasses. Eggshells of DDT + dieldrin-dosed kestrels were 6-23% thinner than eggshells of corresponding controls in different groups and years

Short-tailed shrews: Toxicity and residue relationships of DDT, dieldrin, and endrin

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Blus, L.J.

1978-01-01

Experiments involving dietary toxicity and residue relationships of DDT, dieldrin, and endrin were conducted with short-tailed shrews. Dietary concentrations of DDT dissolved in vegetable oils were usually more toxic than diets containing comparable amounts of powdered DDT. Younger shrews, particularly females, were more tolerant of powdered DDT than older animals; yet, there were no conspicuous age differences in toxicity of DDT dissolved in oils. In comparison to other mammals, short-tailed shrews are not unusually sensitive to DDT, dieldrin, or endrin on the basis of two-week feeding tests. The influence of age and sex on toxicity of DDT, endrin, and dieldrin was sometimes more important than body weight. Of those shrews of the same age and sex that were fed the same dietary dosage, heavier shrews were more tolerant than lighter individuals; and, heavier shrews tended to lose a greater percentage of body weight before death. There was a range of 15 to 105 DDT equivalents in brains of shrews dying on dietary dosages of DDT. Six shrews fed a high level of DDT seemed to have unusual metabolite capabilities and died with apparent lethal levels of DDD in their brains. Levels of dieldrin in brains of shrews that died on a dietary dosage of dieldrin ranged from 3.7 to 12.6 ppm. In the rates of gain and loss experiments where shrews were given diets containing 400 ppm DDT or 50 ppm dieldrin up to 17 days, high residues were noted in tissues of shrews after two weeks on a contaminated diet and a few died at that time. After shrews were placed on clean food, it was determined that >50% of the dieldrin residues in carcass and brain were lost in 50% of residues of DDT and metabolites in brains after 2 weeks on clean food; males lost nearly 50% of residues in carcasses after two weeks on clean food compared with a loss of only 11% in females.

Novel method for determining DDT in vapour and particulate phases within contaminated indoor air in a malaria area of South Africa

Energy Technology Data Exchange (ETDEWEB)

Naude, Yvette, E-mail: yvette.naude@up.ac.za [Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria (South Africa); Rohwer, Egmont R., E-mail: egmont.rohwer@up.ac.za [Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria (South Africa)

2012-06-12

Highlights: Black-Right-Pointing-Pointer We present a novel denuder for the determination of DDT in contaminated indoor air. Black-Right-Pointing-Pointer Single step concentration of vapour phase on PDMS, particulate phase on filter. Black-Right-Pointing-Pointer Solvent-free green technique, sample extraction not required. Black-Right-Pointing-Pointer Ratios of airborne p,p Prime -DDD/p,p Prime -DDT and of o,p Prime -DDT/p,p Prime -DDT are unusual. Black-Right-Pointing-Pointer Insecticidal efficacy of technical DDT may be compromised. - Abstract: The organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control in certain areas of South Africa. The strict Stockholm Convention on Persistent Organic Pollutants (POPs) allows spraying on the inside of traditional dwellings with DDT. In rural villages contaminated dust presents an additional pathway for exposure to DDT. We present a new method for the determination of DDT in indoor air where separate vapour and particulate samples are collected in a single step with a denuder configuration of a multi-channel open tubular silicone rubber (polydimethylsiloxane (PDMS)) trap combined with a micro quartz fibre filter. The multi-channel PDMS trap section of the denuder concentrates vapour phase insecticide whereas particle associated insecticide is transferred downstream where it is collected on a micro-fibre filter followed by a second multi-channel PDMS trap to capture the blow-off from the filter. The multi-channel PDMS trap and filter combination are designed to fit a commercial thermal desorber for direct introduction of samples into a GC-MS. The technique is solvent-free. Analyte extraction and sample clean-up is not required. Two fractions, vapour phase and particulate phase p,p Prime -DDT, o,p Prime -DDT; p,p Prime -DDD, o,p Prime -DDD; p,p Prime -DDE and o,p Prime -DDE in 4 L contaminated indoor air, were each quantitatively analysed by GC-MS using

DDT Vertical Migration and Formation of Accumulation Layer in Pesticide-Producing Sites.

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Liu, Li; Bai, Liping; Man, Changgeng; Liang, Wuhong; Li, Fasheng; Meng, Xiaoguang

2015-08-04

Soil samples were collected at various depths (0.5-21.5 m) from ten boreholes that were drilled with a SH-30 Model Rig, four of which were at a dicofol production site while six were at a dichlorodiphenyltrichloroethane (DDT) production site. In industrial sites, the shallow soils at depths of 0-2 m were mostly backfill soils, which cannot represent the contamination situation of the sites. The contaminated levels in the deep original soil can represent the situation in contaminated sites. All the soil samples investigated at the DDT and dicofol production sites were found to be seriously polluted. The contents of both DDT (0.6-6071 mg/kg) and dicofol (0.5-1440 mg/kg) were much higher at the dicofol production site than at the DDT production site (DDTs, 0.01-664.6 mg/kg; dicofol, DDT identify how long DDTs have remained in the soil. It is debatable that the half-life of DDT inputted to soils is about 20-30 years, maybe longer than the generally recognized time.

Insights into DDT Resistance from the Drosophila melanogaster Genetic Reference Panel.

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Schmidt, Joshua M; Battlay, Paul; Gledhill-Smith, Rebecca S; Good, Robert T; Lumb, Chris; Fournier-Level, Alexandre; Robin, Charles

2017-11-01

Insecticide resistance is considered a classic model of microevolution, where a strong selective agent is applied to a large natural population, resulting in a change in frequency of alleles that confer resistance. While many insecticide resistance variants have been characterized at the gene level, they are typically single genes of large effect identified in highly resistant pest species. In contrast, multiple variants have been implicated in DDT resistance in Drosophila melanogaster ; however, only the Cyp6g1 locus has previously been shown to be relevant to field populations. Here we use genome-wide association studies (GWAS) to identify DDT-associated polygenes and use selective sweep analyses to assess their adaptive significance. We identify and verify two candidate DDT resistance loci. A largely uncharacterized gene, CG10737 , has a function in muscles that ameliorates the effects of DDT, while a putative detoxifying P450, Cyp6w1 , shows compelling evidence of positive selection. Copyright © 2017 by the Genetics Society of America.

Levels and Determinants of DDT and DDE Exposure in the VHEMBE Cohort.

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Gaspar, Fraser W; Chevrier, Jonathan; Quirós-Alcalá, Lesliam; Lipsitt, Jonah M; Barr, Dana Boyd; Holland, Nina; Bornman, Riana; Eskenazi, Brenda

2017-07-07

Although indoor residual spraying (IRS) is an effective tool for malaria control, its use contributes to high insecticide exposure in sprayed communities and raises concerns about possible unintended health effects. The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort study initiated in 2012 to characterize prenatal exposure to IRS insecticides and exposures' impacts on child health and development in rural South Africa. In this report, we describe the VHEMBE cohort and dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) serum concentrations measured in VHEMBE mothers when they presented for delivery. In addition, we applied a causal inference framework to estimate the potential reduction in population-level p , p' -DDT and p , p' -DDE serum concentrations under five hypothetical interventions. A total of 751 mothers were enrolled. Serum concentrations of p , p' isomers of DDT and DDE were above the limit of detection (LOD) in ≥98% of the samples, whereas the o , p' isomers were above the LOD in at least 80% of the samples. Median (interquartile range) p , p' -DDT and p , p' -DDE serum concentrations for VHEMBE cohort participants were 55.3 (19.0-259.3) and 242.2 (91.8-878.7) ng/g-lipid, respectively. Mothers reporting to have lived in a home sprayed with DDT for malaria control had ~5-7 times higher p , p' -DDT and p , p' -DDE serum concentrations than those who never lived in a home sprayed with DDT. Of the five potential interventions tested, we found increasing access to water significantly reduced p , p' -DDT exposure and increasing the frequency of household wet mopping significantly reduced p , p' -DDT and p , p' -DDE exposure. Our findings suggest that several intervention approaches may reduce DDT/DDE exposure in pregnant women living in IRS communities. https://doi.org/10.1289/EHP353.

Application of the Malaria Management Model to the Analysis of Costs and Benefits of DDT versus Non-DDT Malaria Control

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Pedercini, Matteo; Movilla Blanco, Santiago; Kopainsky, Birgit

2011-01-01

Introduction DDT is considered to be the most cost-effective insecticide for combating malaria. However, it is also the most environmentally persistent and can pose risks to human health when sprayed indoors. Therefore, the use of DDT for vector control remains controversial. Methods In this paper we develop a computer-based simulation model to assess some of the costs and benefits of the continued use of DDT for Indoor Residual Spraying (IRS) versus its rapid phase out. We apply the prototype model to the aggregated sub Saharan African region. For putting the question about the continued use of DDT for IRS versus its rapid phase out into perspective we calculate the same costs and benefits for alternative combinations of integrated vector management interventions. Results Our simulation results confirm that the current mix of integrated vector management interventions with DDT as the main insecticide is cheaper than the same mix with alternative insecticides when only direct costs are considered. However, combinations with a stronger focus on insecticide-treated bed nets and environmental management show higher levels of cost-effectiveness than interventions with a focus on IRS. Thus, this focus would also allow phasing out DDT in a cost-effective manner. Although a rapid phase out of DDT for IRS is the most expensive of the tested intervention combinations it can have important economic benefits in addition to health and environmental impacts that are difficult to assess in monetary terms. Those economic benefits captured by the model include the avoided risk of losses in agricultural exports. Conclusions The prototype simulation model illustrates how a computer-based scenario analysis tool can inform debates on malaria control policies in general and on the continued use of DDT for IRS versus its rapid phase out in specific. Simulation models create systematic mechanisms for analyzing alternative interventions and making informed trade offs. PMID:22140467

Application of the malaria management model to the analysis of costs and benefits of DDT versus non-DDT malaria control.

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Matteo Pedercini

Full Text Available INTRODUCTION: DDT is considered to be the most cost-effective insecticide for combating malaria. However, it is also the most environmentally persistent and can pose risks to human health when sprayed indoors. Therefore, the use of DDT for vector control remains controversial. METHODS: In this paper we develop a computer-based simulation model to assess some of the costs and benefits of the continued use of DDT for Indoor Residual Spraying (IRS versus its rapid phase out. We apply the prototype model to the aggregated sub Saharan African region. For putting the question about the continued use of DDT for IRS versus its rapid phase out into perspective we calculate the same costs and benefits for alternative combinations of integrated vector management interventions. RESULTS: Our simulation results confirm that the current mix of integrated vector management interventions with DDT as the main insecticide is cheaper than the same mix with alternative insecticides when only direct costs are considered. However, combinations with a stronger focus on insecticide-treated bed nets and environmental management show higher levels of cost-effectiveness than interventions with a focus on IRS. Thus, this focus would also allow phasing out DDT in a cost-effective manner. Although a rapid phase out of DDT for IRS is the most expensive of the tested intervention combinations it can have important economic benefits in addition to health and environmental impacts that are difficult to assess in monetary terms. Those economic benefits captured by the model include the avoided risk of losses in agricultural exports. CONCLUSIONS: The prototype simulation model illustrates how a computer-based scenario analysis tool can inform debates on malaria control policies in general and on the continued use of DDT for IRS versus its rapid phase out in specific. Simulation models create systematic mechanisms for analyzing alternative interventions and making informed trade

Prenatal Exposure to the Pesticide DDT and Hypertension Diagnosed in Women before Age 50: A Longitudinal Birth Cohort Study

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Cirillo, Piera M.; Terry, Mary Beth; Krigbaum, Nickilou Y.; Flom, Julie D.; Cohn, Barbara A.

2013-01-01

Background: Elevated levels of the pesticide DDT (dichlorodiphenyltrichloroethane) have been positively associated with blood pressure and hypertension in studies among adults. Accumulating epidemiologic and toxicologic evidence suggests that hypertension during adulthood may also be affected by earlier life and possibly the prenatal environment. Objectives: We assessed whether prenatal exposure to the pesticide DDT increases risk of adult hypertension. Methods: We examined concentrations of DDT (p,p´- and o,p´-) and its metabolite p,p´-DDE (dichlorodiphenyldichloroethylene) in prenatal serum samples from a subset of women (n = 527) who had participated in the prospective Child Health and Development Studies birth cohort in the San Francisco Bay area while they were pregnant between 1959 and 1967. We surveyed daughters 39–47 years of age by telephone interview from 2005 to 2008 to obtain information on self-reported physician-diagnosed hypertension and use of hypertensive medication. We used multivariable regression analysis of time to hypertension based on the Cox proportional hazards model to estimate relative rates for the association between prenatal DDT exposures and hypertension treated with medication in adulthood, with adjustment for potential confounding by maternal, early-life, and adult exposures. Results: Prenatal p,p´-DDT exposure was associated with hypertension [adjusted hazard ratio (aHR) = 3.6; 95% CI: 1.8, 7.2 and aHR = 2.5; 95% CI: 1.2, 5.3 for middle and high tertiles of p,p´-DDT relative to the lowest tertile, respectively]. These associations between p,p´-DDT and hypertension were robust to adjustment for independent hypertension risk factors as well as sensitivity analyses. Conclusions: These findings suggest that the association between DDT exposure and hypertension may have its origins early in development. PMID:23591545

Toxicogenomic investigation of Tetrahymena thermophila exposed to dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

Science.gov (United States)

Chang, Yue; Feng, LiFang; Miao, Wei

2011-07-01

Dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are persistent in the environment and cause continuous toxic effects in humans and aquatic life. Tetrahymena thermophila has the potential for use as a model for research regarding toxicants. In this study, this organism was used to analyze a genome-wide microarray generated from cells exposed to DDT, TBT and TCDD. To accomplish this, genes differentially expressed when treated with each toxicant were identified, after which their functions were categorized using GO enrichment analysis. The results suggested that the responses of T. thermophila were similar to those of multicellular organisms. Additionally, the context likelihood of relatedness method (CLR) was applied to construct a TCDD-relevant network. The T-shaped network obtained could be functionally divided into two subnetworks. The general functions of both subnetworks were related to the epigenetic mechanism of TCDD. Based on analysis of the networks, a model of the TCDD effect on T. thermophila was inferred. Thus, Tetrahymena has the potential to be a good unicellular eukaryotic model for toxic mechanism research at the genome level.

Concentraciones de DDT/DDE y riesgo de hipospadias: un estudio piloto de casos y controles DDT/DDE concentrations and risk of hypospadias: a case-control pilot study

Directory of Open Access Journals (Sweden)

Silvia Flores-Luévano

2003-12-01

Full Text Available OBJETIVO: Evaluar la asociación entre los niveles séricos maternos de DDT/DDE y el riesgo de hipospadias. MATERIAL Y MÉTODOS: Estudio de casos y controles, efectuado en la Ciudad de México durante el periodo 1997-1999, con 41 casos de hipospadias y 28 controles. La informacion obtenida por cuestionario y las muestras sanguíneas fueron evaluadas mediante modelos multivariados de regresión logística. RESULTADOS: Las concentraciones materna de DDT y DDE no mostraron asociación con el riesgo de hipospadias (RM 1.13; IC 95% 0.24-5.29 y RM 0.48; IC 95% 0.15-1.60, respectivamente. Los predictores encontrados fueron hijos de madres con mayor edad (RM 8.69; IC 95% 1.69-44.9, y la actividad laboral durante el embarazo (RM, 4.68; IC 95% 1.15-18.9. CONCLUSIONES: Dado que se cuenta con escasa información sobre los efectos endocrinos a diferentes concentraciones de DDT/DDE en humanos, la dosis pudiera ser un factor determinante sobre el tipo de efecto.OBJECTIVE: To evaluate the association between maternal serum DDT/DDE levels and risk of hypospadias. MATERIAL AND METHODS: A case-control study in Mexico City was conducted during 1997-1999 among 41 subjects with hypospadias and 28 controls. Blood samples were obtained from study subjects. Information was obtained using a standardized questionnaire. Data were analyzed using multivariate logistic regression models. RESULTS: Maternal DDT and DDE levels showed no association with hypospadias (OR 1.13; 95% CI 0.24-5.29 and OR=0.48; 95% CI 0.15-1.60, respectively. Associated factors were older age of mothers (OR 8.69; 95% CI 1.69-44.9, and working during pregnancy (OR 4.68; 95% CI 1.15-18.9. CONCLUSIONS: Information about the endocrine effects of different levels of DDT/DDE in human subjects is scarce; dosage may be a determinant factor of the type of effect.

Induction of phosphatidylcholine biosynthesis via CDPcholine pathway in lung and liver of rats following intratracheal administration of DDT and endosulfan

International Nuclear Information System (INIS)

Narayan, S.; Dani, H.M.; Misra, U.K.

1989-01-01

The induction of phosphatidylcholine (PC) biosynthesis via the CDPcholine pathway in lung and liver of rats has been shown following the intratracheal administration of 1,1,1-trichloro-2m2-bis(p-chlorophenyl) ethane (DDT) (5 mg/100 g body weight) and endosulfan (1 mg/100 g body weight) for 3 days. Controls received only the vehicle solution (groundnut oil, 0.1 m1/100 g body weight). The treatment of DDT and endosulfan significantly increased the PC contents and the incorporation of radioactive [methyl-3H]choline into PC of lung and liver microsomes. The incorporation of radioactive [methyl-14C]methionine into microsomal PC of lung and liver was not affected significantly by treatment with either of the insecticides. 1,4,5,6,7-hexachloro-5-norbornene-2,3-dimethano cyclic sulfite (endosulfan) administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal) of lung, whereas DDT increased the activity of only latter. In liver, both DDT and endosulfan administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal). However, the activity of phosphocholinetransferase was not affected in both lung and liver microsomes of rats treated with these insecticides. The PC precursor pool sizes, choline and phosphorylcholine, of lung and liver tissues were not altered by DDT and endosulfan treatments. The present results suggest that the increased level of PC and incorporation of radioactive [methyl-3H]choline into microsomal PC could be the result of increased activity of choline kinase and phosphocholine cytidylyltransferase of lung and liver of rats following intratracheal administration of DDT and endosulfan

Reconstruction of historical atmospheric deposition of DDT in the Zempoala Lagoon, in the center of Mexico

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van, Afferden M.; Hansen, A.M.; Fuller, C.C.

2005-01-01

Historical trend in deposition of DDT and its metabolites has been reconstructed by analyzing sediment cores of the Zempoala Lagoon, in the center of Mexico. The small watershed of this mountain lagoon is closed, and it is located between 2.800 and 3.700 masl. It ls neither affected by agriculture nor by permanent populations. The Zempoala Lagoon has an average depth of 3.9 mand a maximum depth of 8.8 m. Sediments were extracted with a eore sampler and analyzed by isotope methods (137CS and 2'OPb) for dating. Average sedimentation rate was determined in 0.129 9 cm" yr', corresponding to a maximum age of the 44 cm eore of approximately 60 years. The first presence of total-DDT oecurs in a depth between 28 and 32 cm of the sediment profile, corresponding to the 1960's, with a concentration of 5.3 I1g kg-'. The maximum eoncentration of total-DDT (13.0I1g kg-') occurs in sediment layers representing the late 1970's and beginning 1980's. More recently the concentration decreases towards the present concentration of 1.6 I1g kg-'. This concentration is below most DDT levels reported in recent sediment studies in the USA. The results indicate that the Zempoala Lagoon represents a natural reeipient for studies of the reconstruction of historical trends of atmospheric contaminant deposition in this region. The limitations of the methodology applied, due to the influenee of biodegradation on the definition of correct historical coneentrations of DDT depositions, are demonstrated.

Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

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Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

2017-07-24

Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

Toxicological effects of benzo(a)pyrene, DDT and their mixture on the green mussel Perna viridis revealed by proteomic and metabolomic approaches.

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Song, Qinqin; Chen, Hao; Li, Yuhu; Zhou, Hailong; Han, Qian; Diao, Xiaoping

2016-02-01

Benzo(a)pyrene (BaP) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants and environmental estrogens (EEs) with known toxicity towards the green mussel, Perna viridis. In this study, the toxic effects of BaP (10 µg/L) and DDT (10 µg/L) and their mixture were assessed in green mussel gills with proteomic and metabolomic approaches. Metabolic responses indicated that BaP mainly caused disturbance in osmotic regulation by significantly decrease in branched chain amino acids, dimethylamine and dimethylglycine in gills of male green mussels after exposure for 7 days. DDT mainly caused disturbance in osmotic regulation and energy metabolism by differential alteration of betaine, dimethylamine, dimethylglycine, amino acids, and succinate in gills of male green mussels. However, the mixture of BaP and DDT didn't show obvious metabolite changes. Proteomic analysis showed different protein expression profiles between different treatment groups, which demonstrated that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced cell apoptosis, disturbance in protein digestion and energy metabolism in gills of green mussels, whereas DDT exposure altered proteins that were associated with oxidative stress, cytoskeleton and cell structure, protein digestion and energy metabolism. However, the mixture of BaP and DDT affected proteins related to the oxidative stress, cytoskeleton and cell structure, protein biosynthesis and modification, energy metabolism, growth and apoptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pleiotropic Effects of DDT Resistance on Male Size and Behaviour.

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Rostant, Wayne G; Bowyer, Jemima; Coupland, Jack; Facey, James; Hosken, David J; Wedell, Nina

2017-07-01

Understanding the evolution and spread of insecticide resistance requires knowing the relative fitness of resistant organisms. In the absence of insecticides, resistance is predicted to be costly. The Drosophila melanogaster DDT resistance allele (DDT-R) is associated with a male mating cost. This could be because resistant males are generally smaller, but DDT-R may also alter courtship behaviours. Here we tested for body size and courtship effects of DDT-R on mating success in competitive and non-competitive mating trials respectively. We also assessed relative aggression in resistant and susceptible males because aggression can also influence mating success. While the effect of DDT-R on male size partly contributed to reduced mating success, resistant males also had lower rates of courtship and were less aggressive than susceptible males. These differences contribute to the observed DDT-R mating costs. Additionally, these pleiotropic effects of DDT-R are consistent with the history and spread of resistance alleles in nature.

Perinatal DDT Exposure Induces Hypertension and Cardiac Hypertrophy in Adult Mice.

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La Merrill, Michele A; Sethi, Sunjay; Benard, Ludovic; Moshier, Erin; Haraldsson, Borje; Buettner, Christoph

2016-11-01

Dichlorodiphenyltrichloroethane (DDT) was used extensively to control malaria, typhus, body lice, and bubonic plague worldwide, until countries began restricting its use in the 1970s. However, the use of DDT to control vector-borne diseases continues in developing countries. Prenatal DDT exposure is associated with elevated blood pressure in humans. We hypothesized that perinatal DDT exposure causes hypertension in adult mice. DDT was administered to C57BL/6J dams from gestational day 11.5 to postnatal day 5. Blood pressure (BP) and myocardial wall thickness were measured in male and female adult offspring. Adult mice were treated with an angiotensin converting enzyme (ACE) inhibitor, captopril, to evaluate sensitivity to amelioration of DDT-associated hypertension by ACE inhibition. We further assessed the influence of DDT exposure on the expression of mRNAs that regulate BP through renal ion transport. Adult mice perinatally exposed to DDT exhibited chronically increased systolic BP, increased myocardial wall thickness, and elevated expression of mRNAs of several renal ion transporters. Captopril completely reversed hypertension in mice perinatally exposed to DDT. These data demonstrate that perinatal exposure to DDT causes hypertension and cardiac hypertrophy in adult offspring. A key mechanism underpinning this hypertension is an overactivated renin angiotensin system because ACE inhibition reverses the hypertension induced by perinatal DDT exposure. Citation: La Merrill M, Sethi S, Benard L, Moshier E, Haraldsson B, Buettner C. 2016. Perinatal DDT exposure induces hypertension and cardiac hypertrophy in adult mice. Environ Health Perspect 124:1722-1727; http://dx.doi.org/10.1289/EHP164.

Comparison of DDT and its metabolites concentrations in cow milk from agricultural and industrial areas.

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Kuba, Jarosław; Tomza-Marciniak, Agnieszka; Pilarczyk, Bogumiła; Tarasewicz, Natalia; Pilarczyk, Renata; Ligocki, Marek

2015-01-01

The risk of pesticidal intoxication in humans is severe, especially because of the strongly negative impact on human health. The consequences of the exposure to these substances may include cancerogenesis or endocrine abnormalities resulting for example in decreased fertility. Therefore, the aim of our study was to evaluate the content of dichlorodiphenyltrichloroethane (DDT) and its metabolites in cow milk from two regions of Poland, varying by level of industrialization. Samples were collected from agricultural (n = 25) and industrial (n = 25) areas, and the concentrations of DDT and its metabolites were evaluated by gas chromatography. Residues of DDT were detected in all the milk samples tested, mostly in the samples from the agricultural area, where a total DDT median concentration reached 0.336 μg L(-1). In the milk samples from the industrial area, the median concentration was lower, at 0.131 μg L(-1). 4,4'-DDT was the main metabolite, constituting 83% of total DDT metabolites. Although none of the samples exceeded the level above which they should be considered dangerous, the results showed that the problem of DDT had not diminished and so should be constantly monitored.

DDT vs. wildlife: Relationships between quantities ingested, toxic effects and tissue storage

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DeWitt, J.B.; Derby, J.V.; Mangan, G.F.

1955-01-01

Symptoms appeared when quail and pheasants were fed diets containing 0.025-0.050% DDT. Symptoms appeared sooner as percentages increased. Young birds seemed more resistant than adults. Median lethal quantity for adult quail was about 1,200 mg./Kg. Young quail showed no ill-effects after ingesting 3,000 mg./Kg. during 10-week period. Adult pheasants died after ingesting 200-300 mg./Kg. Approximately 600 mg./Kg. were required to kill young pheasants. Quantities of DDT stored in tissues were not proportional to amounts administered or to duration of exposure, but were related to severity of symptoms. Concentration of DDT in breast muscles of birds killed by DDT was about 34 micrograms/Gm. in adult quail and 22 micrograms/Gm. in adult pheasants.

Effect of the isothermal transformation temperature on the fine structure of steel-12Kh1MF

International Nuclear Information System (INIS)

Mints, I.I.; Berezina, T.G.; Lanskaya, K.A.

1976-01-01

For detailed analysis of bainite and pearlite in steel 12Kh1MF, homogeneous structures were obtained by isothermal annealing at 350, 450, 500, and 650 0 for 1 h. Isothermal transformation of austenite leads to the formation of bainite at 350-500 0 and pearlite at 650 0 . The austenitizing temperature was 980 0 for both types of samples, with holding for 20 min. For comparison, the plates were quenched from 980 0 and 1050 0 in ice-cold brine. The investigation was conducted with use of light and electron microscopes and x-ray analysis. The long-term strength was also determined. Isothermal treatment of steel 12Kh1MF at 350-500 0 C leads to the formation of a structure consisting of upper and lower bainite. At 500 0 the structure consists primarily of upper bainite, and at 350 0 of lower bainite. With tempering of the steel with a structure of upper and lower bainite at 730 0 for 3 h the dislocations undergo redistribution of the polygonization type within ferrite needles, with development of a cellular substructure. The acicular structure of the matrix is retained in this case. The density and evenness of the distribution of carbides is higher in upper bainite than in lower bainite. Steel 12Kh1MF with a structure of upper bainite is more susceptible to recrystallization as compared with a structure of lower bainite, which is responsible for the higher heat resistance of the latter

Antiprogestin mifepristone inhibits the growth of cancer cells of reproductive and non-reproductive origin regardless of progesterone receptor expression

International Nuclear Information System (INIS)

Tieszen, Chelsea R; Goyeneche, Alicia A; Brandhagen, BreeAnn N; Ortbahn, Casey T; Telleria, Carlos M

2011-01-01

Mifepristone (MF) has been largely used in reproductive medicine due to its capacity to modulate the progesterone receptor (PR). The study of MF has been expanded to the field of oncology; yet it remains unclear whether the expression of PR is required for MF to act as an anti-cancer agent. Our laboratory has shown that MF is a potent inhibitor of ovarian cancer cell growth. In this study we questioned whether the growth inhibitory properties of MF observed in ovarian cancer cells would translate to other cancers of reproductive and non-reproductive origin and, importantly, whether its efficacy is related to the expression of cognate PR. Dose-response experiments were conducted with cancer cell lines of the nervous system, breast, prostate, ovary, and bone. Cultures were exposed to vehicle or increasing concentrations of MF for 72 h and analysed for cell number and cell cycle traverse, and hypodiploid DNA content characteristic of apoptotic cell death. For all cell lines, expression of steroid hormone receptors upon treatment with vehicle or cytostatic doses of MF for 24 h was studied by Western blot, whereas the activity of the G1/S regulatory protein Cdk2 in both treatment groups was monitored in vitro by the capacity of Cdk2 to phosphorylate histone H1. MF growth inhibited all cancer cell lines regardless of tissue of origin and hormone responsiveness, and reduced the activity of Cdk2. Cancer cells in which MF induced G1 growth arrest were less susceptible to lethality in the presence of high concentrations of MF, when compared to cancer cells that did not accumulate in G1. While all cancer cell lines were growth inhibited by MF, only the breast cancer MCF-7 cells expressed cognate PR. Antiprogestin MF inhibits the growth of different cancer cell lines with a cytostatic effect at lower concentrations in association with a decline in the activity of the cell cycle regulatory protein Cdk2, and apoptotic lethality at higher doses in association with increased

Antiprogestin mifepristone inhibits the growth of cancer cells of reproductive and non-reproductive origin regardless of progesterone receptor expression

Directory of Open Access Journals (Sweden)

Ortbahn Casey T

2011-05-01

Full Text Available Abstract Background Mifepristone (MF has been largely used in reproductive medicine due to its capacity to modulate the progesterone receptor (PR. The study of MF has been expanded to the field of oncology; yet it remains unclear whether the expression of PR is required for MF to act as an anti-cancer agent. Our laboratory has shown that MF is a potent inhibitor of ovarian cancer cell growth. In this study we questioned whether the growth inhibitory properties of MF observed in ovarian cancer cells would translate to other cancers of reproductive and non-reproductive origin and, importantly, whether its efficacy is related to the expression of cognate PR. Methods Dose-response experiments were conducted with cancer cell lines of the nervous system, breast, prostate, ovary, and bone. Cultures were exposed to vehicle or increasing concentrations of MF for 72 h and analysed for cell number and cell cycle traverse, and hypodiploid DNA content characteristic of apoptotic cell death. For all cell lines, expression of steroid hormone receptors upon treatment with vehicle or cytostatic doses of MF for 24 h was studied by Western blot, whereas the activity of the G1/S regulatory protein Cdk2 in both treatment groups was monitored in vitro by the capacity of Cdk2 to phosphorylate histone H1. Results MF growth inhibited all cancer cell lines regardless of tissue of origin and hormone responsiveness, and reduced the activity of Cdk2. Cancer cells in which MF induced G1 growth arrest were less susceptible to lethality in the presence of high concentrations of MF, when compared to cancer cells that did not accumulate in G1. While all cancer cell lines were growth inhibited by MF, only the breast cancer MCF-7 cells expressed cognate PR. Conclusions Antiprogestin MF inhibits the growth of different cancer cell lines with a cytostatic effect at lower concentrations in association with a decline in the activity of the cell cycle regulatory protein Cdk2, and

Current implications of past DDT indoor spraying in Oman.

Science.gov (United States)

Booij, Petra; Holoubek, Ivan; Klánová, Jana; Kohoutek, Jiří; Dvorská, Alice; Magulová, Katarína; Al-Zadjali, Said; Čupr, Pavel

2016-04-15

In Oman, DDT was sprayed indoors during an intensive malaria eradication program between 1976 and 1992. DDT can remain for years after spraying and is associated with potential health risk. This raises the concern for human exposure in areas where DDT was used for indoor spraying. Twelve houses in three regions with a different history of DDT indoor spraying were chosen for a sampling campaign in 2005 to determine p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) levels in indoor air, dust, and outdoor soil. Although DDT was only sprayed indoor, p,p'-DDT, p,p'-DDE and p,p'-DDD were also found in outdoor soil. The results indicate that release and exposure continue for years after cessation of spraying. The predicted cancer risk based on concentrations determined in 2005, indicate that there was still a significant cancer risk up to 13 to 16years after indoor DDT spraying. A novel approach, based on region-specific half-lives, was used to predict concentrations in 2015 and showed that more than 21years after spraying, cancer risk for exposure to indoor air, dust, and outdoor soil are acceptable in Oman for adults and young children. The model can be used for other locations and countries to predict prospective exposure of contaminants based on indoor experimental measurements and knowledge about the spraying time-schedule to extrapolate region-specific half-lives and predict effects on the human population years after spraying. Copyright © 2015 Elsevier B.V. All rights reserved.

DDT exposure of frogs: A case study from Limpopo Province, South Africa.

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Viljoen, Ignatius M; Bornman, Riana; Bouwman, Hindrik

2016-09-01

Amphibians are globally under pressure with environmental contaminants contributing to this. Despite caution aired more than 80 years ago of threats posed to amphibians by DDT spraying for disease vector control, no data have been published on concentrations or effects of DDT contamination in frogs from areas where DDT is actively sprayed to control the insect vectors of malaria. In this study, we sampled fat bodies of Xenopus laevis and Xenopus muelleri naturally occurring in an area where indoor residual spraying of DDT is employed and from adjacent, non-sprayed, areas. ΣDDT concentrations ranged between DDT in the eggs of the Grey Heron Ardea cinerea. This suggests that the DDT we found in frogs may have contributed to DDT loadings higher in the food web. These findings, combined with other studies from this area, support the need to reduce and eventually move away from DDT in malaria control safely and sustainably. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nuclear insulin-like growth factor 1 receptor phosphorylates proliferating cell nuclear antigen and rescues stalled replication forks after DNA damage.

Science.gov (United States)

Waraky, Ahmed; Lin, Yingbo; Warsito, Dudi; Haglund, Felix; Aleem, Eiman; Larsson, Olle

2017-11-03

We have previously shown that the insulin-like growth factor 1 receptor (IGF-1R) translocates to the cell nucleus, where it binds to enhancer-like regions and increases gene transcription. Further studies have demonstrated that nuclear IGF-1R (nIGF-1R) physically and functionally interacts with some nuclear proteins, i.e. the lymphoid enhancer-binding factor 1 (Lef1), histone H3, and Brahma-related gene-1 proteins. In this study, we identified the proliferating cell nuclear antigen (PCNA) as a nIGF-1R-binding partner. PCNA is a pivotal component of the replication fork machinery and a main regulator of the DNA damage tolerance (DDT) pathway. We found that IGF-1R interacts with and phosphorylates PCNA in human embryonic stem cells and other cell lines. In vitro MS analysis of PCNA co-incubated with the IGF-1R kinase indicated tyrosine residues 60, 133, and 250 in PCNA as IGF-1R targets, and PCNA phosphorylation was followed by mono- and polyubiquitination. Co-immunoprecipitation experiments suggested that these ubiquitination events may be mediated by DDT-dependent E2/E3 ligases ( e.g. RAD18 and SHPRH/HLTF). Absence of IGF-1R or mutation of Tyr-60, Tyr-133, or Tyr-250 in PCNA abrogated its ubiquitination. Unlike in cells expressing IGF-1R, externally induced DNA damage in IGF-1R-negative cells caused G 1 cell cycle arrest and S phase fork stalling. Taken together, our results suggest a role of IGF-1R in DDT. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Validation of groundwater modelling for DDT and petroleum hydrocarbons at Border Pump Station and Rainy Hollow, northern British Columbia

International Nuclear Information System (INIS)

Dodd, M.; Bright, D.; Hartshorne, B.

2001-01-01

Border Station and Rainy Hollow are inactive booster pumping stations along the Haines-Fairbanks Pipeline in northern British Columbia. An emergency site cleanup was conducted in 1994 after canisters containing DDT [1,1,1-trichloro-2,2-bis(p-chloro phenyl)ethane] were discovered buried in a dump. A detailed site investigation showed that hydrocarbons and DDT were present in soil and groundwater. The major contaminants of concern were DDTs in surface soil, DDTs in subsurface soils and groundwater, and light hydrocarbons in subsurface soils and groundwater. Remedial action took place in the summer of 1997. The canisters, along with soils and other contaminated materials, were excavated and shipped off-site for disposal. A conceptual groundwater model was developed to predict future contaminant releases to the nearby Klehini River. A monitoring program was initiated to validate the groundwater model. From 1997 to 2000, the groundwater was sampled analyzed annually for DDT, metals and hydrocarbons. Results indicated a striking overall consistency in the concentrations of DDT and hydrocarbons in both groundwater and surface water samples, confirming the validity of the 1996 model predictions. 12 refs., 1 tab., 4 figs

Exposure to DDT and diabetic nephropathy among Mexican Americans in the 1999-2004 National Health and Nutrition Examination Survey.

Science.gov (United States)

Everett, Charles J; Thompson, Olivia M; Dismuke, Clara E

2017-03-01

Concentrations of the pesticide DDT (dichlorodiphenyltrichloroethane) and its metabolite DDE (dichlorodiphenyldichloroethylene), in the blood of Mexican Americans, were evaluated to determine their relationships with diabetes and diabetic nephropathy. The data were derived from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 (unweighted N = 1,411, population estimate = 13,760,609). The sample included teens, 12-19 years old, which accounted for 19.8% of the data. The time of the study overlapped the banning of DDT in Mexico in the year 2000, and those participants born in Mexico were exposed to DDT before they immigrated to the US. We sought to better understand the relationship of DDT with diabetes in a race/ethnicity group prone to develop diabetes and exposed to DDT. In this study, nephropathy was defined as urinary albumin to creatinine ratio >30 mg/g, representing microalbuminuria and macroalbuminuria, and total diabetes was defined as diagnosed and undiagnosed diabetes (glycohemoglobin, A1c ≥ 6.5%). The proportion with the isomer p,p'-DDT >0.086 ng/g (above the maximum limit of detection) was 13.3% for Mexican Americans born in the US, and 36.9% for those born in Mexico. Levels of p,p'-DDT >0.086 ng/g were associated with total diabetes with nephropathy (odds ratio = 4.42, 95% CI 2.23-8.76), and with total diabetes without nephropathy (odds ratio = 2.02, 95% CI 1.19-3.44). The third quartile of p,p'-DDE (2.99-7.67 ng/g) and the fourth quartile of p,p'-DDE (≥7.68 ng/g) were associated with diabetic nephropathy and had odds ratios of 5.32 (95% CI 1.05-26.87) and 14.95 (95% CI 2.96-75.48) compared to less than the median, respectively, whereas p,p'-DDE was not associated with total diabetes without nephropathy. The findings of this study differ from those of a prior investigation of the general adult US population in that there were more associations found with the Mexican Americans sample. Published by Elsevier Ltd.

The multifocal electroretinogram (mfERG) in the pig

DEFF Research Database (Denmark)

Voss Kyhn, Maria; Kiilgaard, Jens Folke; Lopez, Ana Garcia

2007-01-01

To establish a method allowing multifocal electroretinography (mfERG) recording with simultaneous fundus monitoring on anaesthetized pigs. In addition we characterize the peaks of the porcine mfERG trace, and compare the visual streak area with the optic nerve head, a known non-response area....... Finally we illustrate the feasibility of the method by performing mfERG after an induced laser burn in the visual streak....

Estimation of human body concentrations of DDT from indoor residual spraying for malaria control

International Nuclear Information System (INIS)

Gyalpo, Tenzing; Fritsche, Lukas; Bouwman, Henk; Bornman, Riana; Scheringer, Martin; Hungerbühler, Konrad

2012-01-01

Inhabitants of dwellings treated with DDT for indoor residual spraying show high DDT levels in blood and breast milk. This is of concern since mothers transfer lipid-soluble contaminants such as DDT via breastfeeding to their children. Focusing on DDT use in South Africa, we employ a pharmacokinetic model to estimate DDT levels in human lipid tissue over the lifetime of an individual to determine the amount of DDT transferred to children during breastfeeding, and to identify the dominant DDT uptake routes. In particular, the effects of breastfeeding duration, parity, and mother's age on DDT concentrations of mother and infant are investigated. Model results show that primiparous mothers have greater DDT concentrations than multiparous mothers, which causes higher DDT exposure of first-born children. DDT in the body mainly originates from diet. Generally, our modeled DDT levels reproduce levels found in South African biomonitoring data within a factor of 3. - Highlights: ► Comparison of one-compartment pharmacokinetic model with biomonitoring data. ► Pre- and postnatal exposure of infants depends on breastfeeding duration and parity. ► Dietary exposure of DDT is the dominant uptake route in South Africa. ► Elimination half-lives of DDT and DDE are shorter in children than in adults. - Model predictions of a one-compartment pharmacokinetic model confirm the trends of DDT found in human samples of inhabitants living in DDT-treated dwellings.

Effect of polychlorinated biphenyls (PCBs) and 1,1,1-trichloro-2,2,-bis (4-chlorophenyl)-ethane (DDT) in follicular fluid on the results of in vitro fertilization-embryo transfer (IVF-ET) programs

Czech Academy of Sciences Publication Activity Database

Jirsová, S.; Mašata, J.; Jech, L.; Zvárová, Jana

2010-01-01

Roč. 93, č. 6 (2010), s. 1831-1836 ISSN 0015-0282 Institutional research plan: CEZ:AV0Z10300504 Keywords : DDD * DDE * DDT * embryos * oocytes * PCB * pregnancy rate Subject RIV: FK - Gynaecology, Childbirth Impact factor: 3.122, year: 2010

Risk assessment for children exposed to DDT residues in various milk types from the Greek market.

Science.gov (United States)

Tsakiris, Ioannis N; Goumenou, Marina; Tzatzarakis, Manolis N; Alegakis, Athanasios K; Tsitsimpikou, Christina; Ozcagli, Eren; Vynias, Dionysios; Tsatsakis, Aristidis M

2015-01-01

The occurrence of residues of DDT and its metabolites was monitored in 196 cow milk samples of various pasteurized commercial types collected from the Greek market. Residue levels were determined by GC-MS analysis. In 97.4% of the samples at least one DDT isomer or one of the DDT metabolites was detected, in levels not exceeding the maximum permitted residue level by the EU. Hazard Index for both carcinogenic and non-carcinogenic effects was estimated under two assumptions: a) using DDT concentrations from positive samples and b) imputing LOD/2 as an arbitrary concentration for negative samples. No statistically significant differences in detected or summed residue (p > 0.05) concentrations between different milk types were observed, with the exception of specific metabolites of DDT in some milk types. Exposure assessment scenarios were developed for children aged 1, 3, 5, 7 and 12 years old based on estimated body weights and daily milk consumption. Hazard Indices for non-carcinogenic effects were below 0.109 covering also carcinogenic effects according to WHO approach. The cancer risk values for carcinogenic effects according to the US EPA Cancer Benchmark Concentration approach, ranged from 0.4 to 18. For both effects the highest values were calculated for the 1- to 3-year-old age groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

Wood mouse and box turtle populations in an area treated annually with DDT for five years

Science.gov (United States)

Stickel, L.F.

1951-01-01

A 117-acre area of dense woodland on the Patuxent Research Refuge received an aerial application of DDT in oil at the rate of 2 pounds per acre gnnually for five years. DDT reached ground level in a much smaller amount (thousandths to hundredths of a pound per acre). Treatment was made during the first week of June of each year from 1945 through 1949. Field studies of the wood mouse population in DDT and check areas showed no significant differences in the two areas before and after the 1949 DDT treatment. There was no significant difference between trapping samples taken in DDT and check areas in 1945 and those taken in 1949. Field studies of the box turtles in DDT and check areas in 1945 and 1949 showed no significant difference in population size. Growth of the four young turtles taken in the DDT area in both 1945 and 1949 appeared to be normal in comparison with growth of check area turtles.

DDT Analysis of Wetland Sediments in Upper Escambia Bay, Florida

Science.gov (United States)

Hopko, M. N.; Wright, J.; Liebens, J.; Vaughan, P.

2017-12-01

Dichlorodiphenyltrichloroethane (DDT) was a commonly used pesticide from World War II through the 1960's. DDT is generally used to control mosquito populations and as an agricultural insecticide. The pesticide and its degradation products (DDD and DDE) can bioaccumulate within ecosystems having negative implications for animal and human health. Consequently, DDT usage was banned in the United States in 1973. In a contaminant study performed in Escambia Bay, Florida, in 2009, DDT was present in 25% of study sites, most of which were located in the upper bay wetlands. Concentrations were well above the Florida Department of Environmental Protection's (FDEP) Probable Effect Level (PEL) and ratios of DDT and its metabolites indicated a recent introduction to the system. A follow-up study performed in 2016 found no DDT, but did show DDE at several sites. The current study repeated sampling in May 2017 at sites from the 2009 and 2016 studies. Sediment samples were collected in triplicate using a ponar sampler and DDT, DDD and DDE were extracted using EPA methods 3540c and 3620c. Extracts were analyzed using a gas chromatograph with electron capture detection (GC-ECD) as per EPA method 8081c. Sediment was also analyzed for organic carbon and particle size using an elemental NC analyzer and a laser diffraction particle sizer. Results show the presence of breakdown products DDE and DDD at multiple sites, but no detectable levels of DDT at any site. Sampling sites with high levels of DDT contamination in 2009 show only breakdown products in both 2016 and 2017. Particle size has little influence on DDD or DDE concentrations but OC is a controlling factor as indicated for contaminated sites by Pearson correlations between OC and DDE and DDD of 0.82 and 0.92, respectively. The presence of only DDD and/or DDE in the 2016 and 2017 studies indicates that the parent, DDT, has not been re-introduced into the watershed since 2009 but is degrading in the environment.

Enantiomeric fraction and isomeric composition to assess sources of DDT residues in soils.

Science.gov (United States)

Bosch, Carme; Grimalt, Joan O; Fernández, Pilar

2015-11-01

Chiral pesticides such as o,p'-DDT can undergo enantioselective microbial degradation in soil. Hence, the enantiomeric fraction (EF) of o,p'-DDT was used as an approach to assess potential recent inputs of DDT in the lower part of the Ebro River basin (NE Spain), a region heavily impacted by agricultural and industrial activities, including a dicofol production and a chloro-alkali plants. The EFs of five out of nineteen soils were not different from the racemic value (0.505±0.010), confirming that the Ebro River and some of its tributaries, Segre and Cinca rivers, transported fresh DDT residues despite its ban in Spain during the 90 s. o,p'-DDT/p,p'-DDT ratios in soils suggest that recent use of technical DDT and/or DDT-contaminated dicofol may be responsible for the fresh DDT inputs in the Segre River, while in the Ebro River, they indicate a dominant contribution of technical DDT, likely related to the residues accumulated by the chloro-alkali plant discharges. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preliminary evidence that copper inhibits the degradation of DDT to DDE in pip and stonefruit orchard soils in the Auckland region, New Zealand

International Nuclear Information System (INIS)

Gaw, S.K.; Palmer, G.; Kim, N.D.; Wilkins, A.L.

2003-01-01

Studies in New Zealand orchard soils indicate that elevated Cu concentrations have reduced the ability of the indigenous soil microbial community to degrade DDT to DDE. - Orchards (n=13) were sampled as part of a larger survey investigating agrichemical residues (pesticides and trace elements) in cropping soils in the Auckland region, New Zealand. ΣDDT concentrations in orchard soils ranged from -1 . DDT (o,p'- and p,p'-) comprised at least 40% of the ΣDDT residues in 67% of orchards in which DDT residues were detected. There was a highly significant negative correlation (-0.924, P -1 ) and the ratio of DDE:DDT (0.4-5.2) in pip and stonefruit orchard soils. In further investigations involving five pip and stone fruit orchard sites and one grazing paddock it was found that soil respiration and the ratio of soil microbial carbon to soil carbon (%C mic /Org-C) in orchard soils decreased with increasing copper concentration. These findings are consistent with the conclusion that elevated soil copper concentrations in pip and stone fruit orchard soils in the Auckland region may have reduced the ability of the indigenous soil microbial community to degrade DDT to DDE

Analysis and Evaluation of Manoeuvrability Characteristics of Polish Ferries m/f „Polonia” and m/f „Gryf”

Directory of Open Access Journals (Sweden)

Marek Szymonski

2013-12-01

Full Text Available The paper describes some specific manner of M/F “Polonia” manoeuvring at the Ystad harbour where she is regarded to be “over maximal ship” and also M/F “Gryf” manoeuvring at Trelleborg, taking part into consideration the effect of wind pressure into the ship’s superstructures and houses.

Translesion Synthesis of the N2-2′-Deoxyguanosine Adduct of the Dietary Mutagen IQ in Human Cells: Error-Free Replication by DNA Polymerase κ and Mutagenic Bypass by DNA Polymerases η, ζ, and Rev1

Science.gov (United States)

2016-01-01

Translesion synthesis (TLS) of the N2-2′-deoxyguanosine (dG-N2-IQ) adduct of the carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) was investigated in human embryonic kidney 293T cells by replicating plasmid constructs in which the adduct was individually placed at each guanine (G1, G2, or G3) of the NarI sequence (5′-CG1G2CG3CC-3′). TLS efficiency was 38%, 29%, and 25% for the dG-N2-IQ located at G1, G2, and G3, respectively, which suggests that dG-N2-IQ is bypassed more efficiently by one or more DNA polymerases at G1 than at either G2 or G3. TLS efficiency was decreased 8–35% in cells with knockdown of pol η, pol κ, pol ι, pol ζ, or Rev1. Up to 75% reduction in TLS occurred when pol η, pol ζ, and Rev1 were simultaneously knocked down, suggesting that these three polymerases play important roles in dG-N2-IQ bypass. Mutation frequencies (MFs) of dG-N2-IQ at G1, G2, and G3 were 23%, 17%, and 11%, respectively, exhibiting a completely reverse trend of the previously reported MF of the C8-dG adduct of IQ (dG-C8-IQ), which is most mutagenic at G3 ((2015) Nucleic Acids Res.43, 8340−835126220181). The major type of mutation induced by dG-N2-IQ was targeted G → T, as was reported for dG-C8-IQ. In each site, knockdown of pol κ resulted in an increase in MF, whereas MF was reduced when pol η, pol ι, pol ζ, or Rev1 was knocked down. The reduction in MF was most pronounced when pol η, pol ζ, and Rev1 were simultaneously knocked down and especially when the adduct was located at G3, where MF was reduced by 90%. We conclude that pol κ predominantly performs error-free TLS of the dG-N2-IQ adduct, whereas pols η, pol ζ, and Rev1 cooperatively carry out the error-prone TLS. However, in vitro experiments using yeast pol ζ and κ showed that the former was inefficient in full-length primer extension on dG-N2-IQ templates, whereas the latter was efficient in both error-free and error-prone extensions. We believe that the observed differences between

Survival, growth, detoxifying and antioxidative responses of earthworms (Eisenia fetida) exposed to soils with industrial DDT contamination.

Science.gov (United States)

Shi, Yajuan; Zhang, Qiangbin; Huang, Dunqi; Zheng, Xiaoqi; Shi, Yajing

2016-03-01

The survival, growth, activity of the biotransformation system phase II enzyme glutathione-S-transferase (GST) and the oxidative defense enzyme catalase (CAT) of earthworms exposed to the contaminated soils from a former DDT plant and reference soils were investigated, and compared with the corresponding indicators in simulated soil-earthworm system, unpolluted natural soils with spiked-in DDT series, to identify the toxic effects of DDT on earthworms and their cellular defense system in complex soil system. The results indicated that DDT level in the contaminated soils was significantly higher than that in the reference soils with similar level of other pollutants and soil characters. The mortality, growth inhibition rates, GST and CST activities of earthworms exposed to the contaminated soils were significantly higher than that in reference soils. The contribution of historical DDT in contaminated soils to earthworms was confirmed by the DDT spiked tests. DDT spiked in soils at rates of higher than 200 mg·kg(-1) was significantly toxic to both the survival and the growth of earthworms. DDT significantly stimulated GST and CAT activity in earthworms after 14 days. The CAT and GST activities were also stimulated by DDT exposure at rates of 100 mg·kg(-1) after chronic exposure (42 days). The results provide implications for validating the extrapolation from laboratory simulated soils criteria to contaminated soils and for making site risk assessments. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrences and fate of DDT principal isomers/metabolites, DDA, and o,p'-DDD enantiomers in fish, sediment and water at a DDT-impacted Superfund site.

Science.gov (United States)

Garrison, A W; Cyterski, M; Roberts, K D; Burdette, D; Williamson, J; Avants, J K

2014-11-01

In the 1950s and 60s, discharges from a DDT manufacturing plant contaminated a tributary system of the Tennessee River near Huntsville, Alabama, USA. Regulatory action resulted in declaring the area a Superfund site which required remediation and extensive monitoring. Monitoring data collected from 1988, after remediation, through 2011 showed annual decreases approximating first-order decay in concentrations of total DDT and its six principal congeners (p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD, p,p'-DDE and o,p'-DDE) in filets from three species of fish. As of 2013, these concentrations met the regulatory requirements of 5 mg/kg or less total DDT for each fish tested. The enantiomer fractions (EF) of chiral o,p'-DDD in smallmouth buffalo and channel catfish were always below 0.5, indicating preferential decay of the (+)-enantiomer of this congener; this EF did not change significantly over 15 years. The often-neglected DDT metabolite p,p'-DDA was found at a concentration of about 20 μg/l in the ecosystem water. Published by Elsevier Ltd.

Detection of DDT and its metabolites in two estuaries of South China using a SPME-based device: First report of p,p'-DDMU in water column

International Nuclear Information System (INIS)

Xing Yuanna; Guo Ying; Xie Mei; Shen Rulang; Zeng, Eddy Y.

2009-01-01

A solid-phase microextration-based sampling method was employed to determine the concentrations of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethene (DDE) and 1-chloro-2,2-bis(p-chlorophenyl)ethene (DDMU), in two estuarine bays, Daya Bay and Hailing Bay, of South China. Six DDT components including p,p'-DDT, o,p'-DDD, p,p'-DDD, o,p'-DDE, p,p'-DDE, and p,p'-DDMU were detected in Hailing Bay, while only p,p'-DDD was found in Daya Bay. p,p'-DDD was the most abundant DDT component in both bays, sharply different from the previous finding in the water column of the Palos Verdes Shelf, California, USA that p,p'-DDE was prevalent. In addition, the occurrence of p,p'-DDMU (with a range of 0.047-0.21 ng/L in Hailing Bay) has not been reported around the globe, and its presence in our study region appeared to stem from dehydrochlorination of p,p'-DDD, favored under aerobic conditions, but further investigations are clearly needed to confirm the mechanism for generation of DDMU in estuarine environments. - DDT and its metabolites, particularly p,p'-DDMU, are detected in the water column of two estuarine bays in South China using a SPME-based sampler

RNAi validation of resistance genes and their interactions in the highly DDT-resistant 91-R strain of Drosophila melanogaster.

Science.gov (United States)

Gellatly, Kyle J; Yoon, Kyong Sup; Doherty, Jeffery J; Sun, Weilin; Pittendrigh, Barry R; Clark, J Marshall

2015-06-01

4,4'-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control. Previous DDT use has resulted in resistance, and with continued use resistance will increase in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, numerous studies done on insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold), however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has validated the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (Mdr50, Mdr65, and Mrp1) involved in DDT resistance. Further, increased sensitivity to DDT in the 91-R strain after intra-abdominal dsRNA injection for Mdr50, Mdr65, and Mrp1 was determined by a DDT contact bioassay, directly implicating these genes in DDT efflux and resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

Endocrine disruption mechanism of o,p'-DDT in mature male tilapia (Oreochromis niloticus)

International Nuclear Information System (INIS)

Leanos-Castaneda, Olga; Kraak, Glen van der; Rodriguez-Canul, Rossanna; Gold, G.

2007-01-01

The aim of the present study was to evaluate, in vivo, the potential of o,p'-DDT to disrupt the endocrine system of mature male tilapia. In particular, the possibility that o,p'-DDT effects were mediated directly via the estrogen receptor (ER). Compounds with known ability to bind to the ER were employed: estradiol to induce and tamoxifen to inhibit the estrogenic effects result of the activation of the ER. In addition, an aromatase inhibitor, 4-hydrxyandrostenedione (4-OHA), was used to assess the ability of o,p'-DDT to induce estrogenic effects in a surrounding of low estradiol concentration. The effects of estradiol and o,p'-DDT were studied alone or in the presence of tamoxifen or 4-OHA at the end of a 12-day period of exposure. The main endpoints measured were plasma alkaline-labile phosphorous (ALP; an indirect indicator of vitellogenin), estradiol, testosterone and o,p'-DDT. It was found that o,p'-DDT was able to induce the vitellogenesis (measured as plasma ALP increase) and decrease the circulating levels of estradiol and testosterone. Interestingly, o,p'-DDT kept this ability in whole fish with low concentrations of estradiol which would exclude endogenous estradiol as indirect mediator of the estrogenic effects induced by o,p'-DDT. In addition, the plasma concentration of o,p'-DDT, instead of that of estradiol, was closely related to the plasma ALP increase induced by o,p'-DDT. This indicates that o,p'-DDT could have directly activated the vitellogenesis. The antiestrogenic action of tamoxifen to inhibit the vitellogenesis and the decrease on plasma estradiol induced by o,p'-DDT indicates that o,p'-DDT can bind directly to the ER. In conclusion, this in vivo study shows that o,p'-DDT has the potential to disrupt the endocrine system and strongly supports that the estrogenic actions of o,p'-DDT involve binding to the ER

Biorremediación de suelo contaminado con pesticidas: caso DDT

OpenAIRE

Bibiana Betancur Corredor; Gustavo Peñuela Mesa; Santiago Alonso Cardona Gallo; Nancy Pino

2013-01-01

El 1,1,1-tricloro-2,2'bis(p-clorofenil)etano (DDT) ha sido usado desde la segunda guerra mundial para controlar enfermedades transmitidas por insectos en humanos y animales domésticos. El uso de estos insecticidas organoclorados se ha prohibido en la mayoría de los países, debido a su persistencia en el ambiente, susceptibilidad de biomagnificación y potencial toxicidad a animales superiores. La biorremediación involucra el uso de microorganismos para degradar contaminantes orgánicos presente...

Mansonella perstans microfilaremic individuals are characterized by enhanced type 2 helper T and regulatory T and B cell subsets and dampened systemic innate and adaptive immune responses.

Directory of Open Access Journals (Sweden)

Manuel Ritter

2018-01-01

Full Text Available The filarial nematode Mansonella perstans is endemic throughout Africa, northern South America and the Caribbean. Interestingly, M. perstans-infected individuals present no distinct clinical picture associated with certain pathology. Due to its relatively silent nature, research on this tropical disease has been neglected, especially M. perstans-driven immune responses. A hindrance in obtaining data on M. perstans-specific responses has been the inability to obtain adult worms since their habitats in serous cavities are difficult to access. Thus, in this study, for the first time, we used Mansonella perstans worm antigen extract as stimulant to obtain filarial-specific recall and immunoglobulin responses from M. perstans microfilaremic individuals (Mp MF+ from Cameroon. Moreover, systemic immune profiles in sera and immune cell composition in peripheral blood from Mp MF+ and amicrofilaremic individuals (Mp MF- were obtained. Our data reveal that Mp MF+ individuals showed significantly reduced cytokine (IL-4, IL-6 and IL-12p70 and chemokine levels (IL-8 and RANTES, but significantly higher MIP-1β as well as increased M. perstans-specific IgG4 levels compared to Mp MF- individuals. In contrast, upon re-stimulation with worm antigen extract, IFN-γ, IL-13, IL-10 and IL-17A secretion was enhanced in cell cultures from Mp MF+ individuals when compared to those from cultures of healthy European individuals. Moreover, analysis of immune cell composition in peripheral blood from Mp MF+ individuals revealed increased type 2 helper T (Th2, natural killer (NK, regulatory B and T cell (Breg and Treg subsets but decreased type 1 regulatory T (Tr1 cells. In summary, this study deciphers for the first time, M. perstans-specific immune responses using worm antigen extract and shows that patent M. perstans infections have distinct Th2, Breg and Treg subsets accompanied with reduced systemic innate and adaptive immune responses and dominant filarial-specific Ig

The Influence of Brightness on Functional Assessment by mfERG: A Study on Scaffolds Used in Retinal Cell Transplantation in Pigs

Directory of Open Access Journals (Sweden)

A. T. Christiansen

2012-01-01

Full Text Available To determine the effect of membrane brightness on multifocal electroretinograms (mfERGs, we implanted poly lactic-co-glycolic acid (PLGA membranes in the subretinal space of 11 porcine eyes. We compared membranes with their native shiny white color with membranes that were stained with a blue dye (Brilliant Blue. Histological and electrophysiological evaluation of the overlying retina was carried out 6 weeks after implantation. Histologically, both white and blue membranes degraded in a spongiform manner leaving a disrupted outer retina with no preserved photoreceptor segments. Multifocal ERG revealed the white membranes to have a significantly higher P1-amplitude ratio than the blue (P=0.027, and a correlation between brightness ratio and P1-amplitude ratio was found (r=0.762. Based on our findings, we conclude that bright subretinal objects can produce normal mfERG amplitude ratios even when the adjacent photoreceptors are missing. Functional assessment with mfERG in scaffold implant studies should therefore be evaluated with care.

Assessment of DDT levels in selected environmental media and biological samples from Mexico and Central America.

Science.gov (United States)

Pérez-Maldonado, Iván N; Trejo, Antonio; Ruepert, Clemens; Jovel, Reyna del Carmen; Méndez, Mónica Patricia; Ferrari, Mirtha; Saballos-Sobalvarro, Emilio; Alexander, Carlos; Yáñez-Estrada, Leticia; Lopez, Dania; Henao, Samuel; Pinto, Emilio R; Díaz-Barriga, Fernando

2010-03-01

Taking into account the environmental persistence and the toxicity of DDT, the Pan American Health Organization (PAHO) organized a surveillance program in Mesoamerica which included the detection of residual DDT in environmental (soil) and biological samples (fish tissue and children's blood). This program was carried out in communities from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. This paper presents the first report of that program. As expected, the results show that the levels for [summation operator] DDT in soil (outdoor or indoor) and fish samples in the majority of the locations studied are below guidelines. However, in some locations, we found children with high concentrations of DDT as in Mexico (mean level 50.2 ng/mL). Furthermore, in some communities and for some matrices, the DDT/DDE quotient is higher than one and this may reflect a recent DDT exposure. Therefore, more efforts are needed to avoid exposure and to prevent the reintroduction of DDT into the region. In this regard it is important to know that under the surveillance of PAHO and with the support of UNEP, a regional program in Mesoamerica for the collection and disposal of DDT and other POPs stockpiles is in progress. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Examining the efficiency and interdependence of US credit and stock markets through MF-DFA and MF-DXA approaches

Science.gov (United States)

Shahzad, Syed Jawad Hussain; Nor, Safwan Mohd; Mensi, Walid; Kumar, Ronald Ravinesh

2017-04-01

This study examines the power law properties of 11 US credit and stock markets at the industry level. We use multifractal detrended fluctuation analysis (MF-DFA) and multifractal detrended cross-correlation analysis (MF-DXA) to first investigate the relative efficiency of credit and stock markets and then evaluate the mutual interdependence between CDS-equity market pairs. The scaling exponents of the MF-DFA approach suggest that CDS markets are relatively more inefficient than their equity counterparts. However, Banks and Financial credit markets are relatively more efficient. Basic Materials (both CDS and equity indices) is the most inefficient sector of the US economy. The cross-correlation exponents obtained through MF-DXA also suggest that the relationship of the CDS and equity sectors within and across markets is multifractal for all pairs. Within the CDS market, Basic Materials is the most dependent sector, whereas equity market sectors can be divided into two distinct groups based on interdependence. The pair-wise dependence between Basic Materials sector CDSs and the equity index is also the highest. The degree of cross-correlation shows that the sectoral pairs of CDS and equity markets belong to a persistent cross-correlated series within selected time intervals.

Fish contamination with DDT due to malaria control in the Brazilian Amazon

Energy Technology Data Exchange (ETDEWEB)

Torres, J P.M.; Meire, R; Azeredo, A; Malm, O [Lab. de Radiosotopos Eduardo Penna Franca, IBCCF - UFRJ, RJ (Brazil); D' Amato, C [Programa de Pos Graduacao em Ciencias dos Alimentos, IQ-UFRJ, RJ (Brazil); Saldanha, G; Bastos, W [Lab. de Biogeoquimica, UNIR, Porto Velho (Brazil); Claudio, L [International Training Environmental Medicine, The Mount Sinai School of Medicine, Community and Preventive Medicine Dept., NY (United States); Markowitz, S [Center for Biology of the Natural Systems, Queens Coll. New York (United States)

2004-09-15

The DDT, a term used to refer to Dichlorodiphenyltrichloroethane, is an organochlorine pesticide first synthesized in 1874, but its properties as insecticide were discovered only in the late 1930's by the chemist Paul Muller, who won the Nobel Prize in 1948. Since its discovery, DDT use revolutionized the control concepts against malaria and other tropical insect-borne diseases. A large-scale industrial production started in 1943 and it was used in great quantities mainly for the agricultural and forest pest control. A smaller quantity of the world production (20-30%) was used in tropical disease control. In 1946 it was established a regular system of DDT applications in Amazon houses. Its use became common in malaria vector control and other tropical diseases, like leishmaniasis. DDT began to be restricted after the discovery of its toxicity against wild animals, especially top predators and due to potential toxic effects against humans. The DDT restrictive measures in Brazil started in 19714. In 1985 DDT was prohibited for agricultural purposes, but continued to be use for Public Health Campaigns, under the responsibility of FUNASA, the Brazilian National Health Foundation. An investigation conducted by Vieira et al. detected {sigma}ODDT in soil, sediments and chicken eggs from an area seven and nine years after its last application for leishmaniasis vector control near the sprayed sites. Today DDT is recognized as one of the twelve Persistent Organic Pollutants - POPs. Concerning DDT in food, based on clinical observations as well as experimental animals, the annual Joint FAO/WHO Meetings on Pesticide Residues held in 20008 estimated a Provisional Tolerable Daily Intake (PTDI) for DDT in 0.01 mg/kg/day. Marien and Laflamme9 have proposed a Tolerable Daily Intake (TDI) for breast feedings infants of 5 x 10{sup -3}mg/kg/day, and conducted an assessment to evaluate the public health significance of eating {sigma}DDT contaminated fish, accomplished by establishing a

Fish contamination with DDT due to malaria control in the Brazilian Amazon

Energy Technology Data Exchange (ETDEWEB)

Torres, J.P.M.; Meire, R.; Azeredo, A.; Malm, O. [Lab. de Radiosotopos Eduardo Penna Franca, IBCCF - UFRJ, RJ (Brazil); D' Amato, C. [Programa de Pos Graduacao em Ciencias dos Alimentos, IQ-UFRJ, RJ (Brazil); Saldanha, G.; Bastos, W. [Lab. de Biogeoquimica, UNIR, Porto Velho (Brazil); Claudio, L. [International Training Environmental Medicine, The Mount Sinai School of Medicine, Community and Preventive Medicine Dept., NY (United States); Markowitz, S. [Center for Biology of the Natural Systems, Queens Coll. New York (United States)

2004-09-15

The DDT, a term used to refer to Dichlorodiphenyltrichloroethane, is an organochlorine pesticide first synthesized in 1874, but its properties as insecticide were discovered only in the late 1930's by the chemist Paul Muller, who won the Nobel Prize in 1948. Since its discovery, DDT use revolutionized the control concepts against malaria and other tropical insect-borne diseases. A large-scale industrial production started in 1943 and it was used in great quantities mainly for the agricultural and forest pest control. A smaller quantity of the world production (20-30%) was used in tropical disease control. In 1946 it was established a regular system of DDT applications in Amazon houses. Its use became common in malaria vector control and other tropical diseases, like leishmaniasis. DDT began to be restricted after the discovery of its toxicity against wild animals, especially top predators and due to potential toxic effects against humans. The DDT restrictive measures in Brazil started in 19714. In 1985 DDT was prohibited for agricultural purposes, but continued to be use for Public Health Campaigns, under the responsibility of FUNASA, the Brazilian National Health Foundation. An investigation conducted by Vieira et al. detected {sigma}ODDT in soil, sediments and chicken eggs from an area seven and nine years after its last application for leishmaniasis vector control near the sprayed sites. Today DDT is recognized as one of the twelve Persistent Organic Pollutants - POPs. Concerning DDT in food, based on clinical observations as well as experimental animals, the annual Joint FAO/WHO Meetings on Pesticide Residues held in 20008 estimated a Provisional Tolerable Daily Intake (PTDI) for DDT in 0.01 mg/kg/day. Marien and Laflamme9 have proposed a Tolerable Daily Intake (TDI) for breast feedings infants of 5 x 10{sup -3}mg/kg/day, and conducted an assessment to evaluate the public health significance of eating {sigma}DDT contaminated fish, accomplished by

Enhanced reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide

International Nuclear Information System (INIS)

Li, F.B.; Li, X.M.; Zhou, S.G.; Zhuang, L.; Cao, F.; Huang, D.Y.; Xu, W.; Liu, T.X.; Feng, C.H.

2010-01-01

The transformation of DDT was studied in an anaerobic system of dissimilatory iron-reducing bacteria (Shewanella decolorationis S12) and iron oxide (α-FeOOH). The results showed that S. decolorationis could reduce DDT into DDD, and DDT transformation rate was accelerated by the presence of α-FeOOH. DDD was observed as the primary transformation product, which was demonstrated to be transformed in the abiotic system of Fe 2+ + α-FeOOH and the system of DIRB + α-FeOOH. The intermediates of DDMS and DBP were detected after 9 months, likely suggesting that reductive dechlorination was the main dechlorination pathway of DDT in the iron-reducing system. The enhanced reductive dechlorination of DDT was mainly due to biogenic Fe(II) sorbed on the surface of α-FeOOH, which can serve as a mediator for the transformation of DDT. This study demonstrated the important role of DIRB and iron oxide on DDT and DDD transformation under anaerobic iron-reducing environments. - This is the first case reporting the reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide.

Enhanced reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide

Energy Technology Data Exchange (ETDEWEB)

Li, F.B., E-mail: cefbli@soil.gd.c [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Li, X.M. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Zhou, S.G.; Zhuang, L. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Cao, F. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Huang, D.Y.; Xu, W.; Liu, T.X. [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Feng, C.H. [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China)

2010-05-15

The transformation of DDT was studied in an anaerobic system of dissimilatory iron-reducing bacteria (Shewanella decolorationis S12) and iron oxide (alpha-FeOOH). The results showed that S. decolorationis could reduce DDT into DDD, and DDT transformation rate was accelerated by the presence of alpha-FeOOH. DDD was observed as the primary transformation product, which was demonstrated to be transformed in the abiotic system of Fe{sup 2+} + alpha-FeOOH and the system of DIRB + alpha-FeOOH. The intermediates of DDMS and DBP were detected after 9 months, likely suggesting that reductive dechlorination was the main dechlorination pathway of DDT in the iron-reducing system. The enhanced reductive dechlorination of DDT was mainly due to biogenic Fe(II) sorbed on the surface of alpha-FeOOH, which can serve as a mediator for the transformation of DDT. This study demonstrated the important role of DIRB and iron oxide on DDT and DDD transformation under anaerobic iron-reducing environments. - This is the first case reporting the reductive dechlorination of DDT in an anaerobic system of dissimilatory iron-reducing bacteria and iron oxide.

Bisphenol A, Dichlorodiphenyltrichloroethane (DDT) and Vinclozolin Affect ex-vivo Uterine Contraction in Rats via Uterotonin (Prostaglandin F2?, Acetylcholine and Oxytocin) Related Pathways

OpenAIRE

Salleh, Naguib; Giribabu, Nelli; Feng, Angeline Oh Mei; Myint, Kyaimon

2015-01-01

Bisphenol-A (BPA), dichrolodiphenyltrichloroethane (DDT) and vinclozolin were found able to induce abnormal uterine contraction. The mechanisms involved remains unclear. We hypothesized that the effect of these compounds were mediated via the uterotonin pathways. Therefore, in this study, effects of BPA, vinclozolin and DDT-only and in combination with uterotonins (PGF-2?, acetylcholine and oxytocin) on the force and pattern of uterine contraction were observed. Methods: Uteri were harvested ...

Tissue localization of DDT and PCB isomers (octa- and tetrachlorobiphenyl) in laying quails

International Nuclear Information System (INIS)

Brandt, I.; Hoegman, P.-G.; Larsson, Y.; Olsson, S.

1978-01-01

Whole-body autoradiography of DDT- 14 C, 2,2',4,5'-tetrachlorobiphenyl- 14 C and 2,2',3,3',4,4',5,6'=octachlorobiphenyl- 14 C in laying quails indicated a strong deposition of radioactivity in the yolk of the growing follicles and the egg, confirming this to be a significant excretion route of lipophilic environmental pollutants in laying birds. A specific uptake of DDT and octachlorobiphenyl, but not of tetrachlorobiphenyl, was observed in the cortical cords of the adrenals. The octachlorobiphenyl was concentrated also in the ovarian stroma. Both DDT and the tetrachlorobiphenyl were excreted in the bile juice to the small intestine. No such excretion of octachlorobiphenyl was observed, indicating its rate of metabolization to be low. All compounds were accumulated and stored in the body fat. A previously described specific accumulation of 2,2',4,5'-tetrachlorobiphenyl in the respiratory tract of mice was not observed in the quail. (author)

Synergistic and Antagonistic Mutation Responses of Human MCL-5 Cells to Mixtures of Benzo[a]pyrene and 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]pyridine: Dose-Related Variation in the Joint Effects of Common Dietary Carcinogens.

Science.gov (United States)

David, Rhiannon; Ebbels, Timothy; Gooderham, Nigel

2016-01-01

Chemical carcinogens such as benzo[a]pyrene (BaP) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) may contribute to the etiology of human diet-associated cancer. Individually, these compounds are genotoxic, but the consequences of exposure to mixtures of these chemicals have not been systematically examined. We determined the mutagenic response to mixtures of BaP and PhIP at concentrations relevant to human exposure (micromolar to subnanomolar). Human MCL-5 cells (metabolically competent) were exposed to BaP or PhIP individually or in mixtures. Mutagenicity was assessed at the thymidine kinase (TK) locus, CYP1A activity was determined by ethoxyresorufin-O-deethylase (EROD) activity and qRT-PCR, and cell cycle was measured by flow cytometry. Mixtures of BaP and PhIP produced dose responses different from those of the individual chemicals; we observed remarkably increased mutant frequency (MF) at lower concentrations of the mixtures (not mutagenic individually), and decreased MF at higher concentrations of the mixtures, than the calculated predicted additive MF of the individual chemicals. EROD activity and CYP1A1 mRNA levels were correlated with TK MF, supporting involvement of the CYP1A family in mutation. Moreover, a cell cycle G2/M phase block was observed at high-dose combinations, consistent with DNA damage sensing and repair. Mixtures of these genotoxic chemicals produced mutation responses that differed from those expected for the additive effects of the individual chemicals. The increase in MF for certain combinations of chemicals at low concentrations that were not genotoxic for the individual chemicals, as well as the nonmonotonic dose response, may be important for understanding the mutagenic potential of food and the etiology of diet-associated cancers. David R, Ebbels T, Gooderham N. 2016. Synergistic and antagonistic mutation responses of human MCL-5 cells to mixtures of benzo[a]pyrene and 2-amino-1-methyl-6-phenylimidazo[4,5-b

Behaviour of 14C-DDT in Sudan Gezira soil

International Nuclear Information System (INIS)

Abdalla, A.M.; El-Zorgani, G.A.

1988-01-01

Field cylinders as described in the model experiment for determination of 14 C-DDT in Sudan Gezira soil were prepared and samples were collected for determination of 14 C-activity at various intervals. About 83-87% of the applied radioactivity was recovered in the extracts from the top 10 cm layer of soil. The loss rate of the chemical from soil increased with time apparently by volatilization and thermal degradation due to high soil temperature, intensive solar radiation and low soil organic matter. This resulted in a half-life of approx. 5 weeks. The major part of the chemical and possible metabolites were detected in the top 10 cm layer. Approximately 8-10% of the applied 14 C was detected in samples collected after 16-20 weeks. TLC and autoradiography indicated the presence of p,p'-DDT and p,p'-DDE as the major metabolite. Also traces of TDE were detected in some samples. These results showed that under Sudanese tropical conditions, DDT dissipates very rapidly in soils compared to dissipation in temperate regions. (author). 6 refs, 2 tabs

Uptake, absorption efficiency and elimination of DDT in marine phytoplankton, copepods and fish

International Nuclear Information System (INIS)

Wang Xinhong; Wang Wenxiong

2005-01-01

Uptake, absorption efficiency and elimination of DDT were measured in marine phytoplankton, copepods (Acartia erythraea) and fish (mangrove snappers Lutjanus argentimaculatus). The uptake rate constant of DDT from water decreased with increasing trophic level. The dietary absorption efficiency (AE) of DDT was 10-29% in copepods and 72-99% in fish. Food concentration did not significantly affect the AEs of DDT, but the AEs varied considerably among the different food diets. The elimination rate constants of DDT by the copepods were comparable following uptake from the diet and from the water. Elimination of DDT from the fish was exceedingly low. Both aqueous and dietary uptake are equally important for DDT accumulation in the copepods. In fish, dissolved exposure is a more significant route than intake from the diet. The predicted trophic transfer factors in the copepods and the fish are consistent with the field measurements in marine zooplankton and fish. -Biomagnification and exposure of DDT in a marine food chain is demonstrated by measurements of uptake and elimination rates and kinetic modeling

Crucial factors of the inflammatory microenvironment (IL-1β/TNF-α/TIMP-1) promote the maintenance of the malignant hemopoietic clone of myelofibrosis: an in vitro study.

Science.gov (United States)

Sollazzo, Daria; Forte, Dorian; Polverelli, Nicola; Romano, Marco; Perricone, Margherita; Rossi, Lara; Ottaviani, Emanuela; Luatti, Simona; Martinelli, Giovanni; Vianelli, Nicola; Cavo, Michele; Palandri, Francesca; Catani, Lucia

2016-07-12

Along with molecular abnormalities (mutations in JAK2, Calreticulin (CALR) and MPL genes), chronic inflammation is the major hallmark of Myelofibrosis (MF). Here, we investigated the in vitro effects of crucial factors of the inflammatory microenvironment (Interleukin (IL)-1β, Tumor Necrosis Factor (TNF)-α, Tissue Inhibitor of Metalloproteinases (TIMP)-1 and ATP) on the functional behaviour of MF-derived circulating CD34+ cells.We found that, regardless mutation status, IL-1β or TNF-α increases the survival of MF-derived CD34+ cells. In addition, along with stimulation of cell cycle progression to the S-phase, IL-1β or TNF-α ± TIMP-1 significantly stimulate(s) the in vitro clonogenic ability of CD34+ cells from JAK2V617 mutated patients. Whereas in the JAK2V617F mutated group, the addition of IL-1β or TNF-α + TIMP-1 decreased the erythroid compartment of the CALR mutated patients. Megakaryocyte progenitors were stimulated by IL-1β (JAK2V617F mutated patients only) and inhibited by TNF-α. IL-1β + TNF-α + C-X-C motif chemokine 12 (CXCL12) ± TIMP-1 highly stimulates the in vitro migration of MF-derived CD34+ cells. Interestingly, after migration toward IL-1β + TNF-α + CXCL12 ± TIMP-1, CD34+ cells from JAK2V617F mutated patients show increased clonogenic ability.Here we demonstrate that the interplay of these inflammatory factors promotes and selects the circulating MF-derived CD34+ cells with higher proliferative activity, clonogenic potential and migration ability. Targeting these micro-environmental interactions may be a clinically relevant approach.

Observations of the Mf ocean tide from Geosat altimetry

Science.gov (United States)

Cartwright, David E.; Ray, Richard D.

1990-01-01

Zonal averages of the 13.66-day Mf tide are derived from one year of Geosat altimetry records. The orbit errors are reduced by 1/revolution corrections taken over long (several day) arcs. The short-period tides are removed using a model previously derived from the same data. The Mf zonal averages indicate definite nonequilibrium character at nearly all latitudes. The imaginary admittances indicate a Q of at least 8; such a value is consistent with a simplified theory of coupled gravitational and vorticity modes and suggests a value for Proudman's 'friction period' about 123 days.

Impact of copper based fungicides on the degradation of 4,4 DDT to 4,4 DDE in PIP and stonefruit orchard soils in the Walkato Region, New Zealand

Energy Technology Data Exchange (ETDEWEB)

Gaw, S. [Univ. of Waikato, Hamilton (New Zealand)]|[Environment Waikato, Hamilton (New Zealand); Palmer, G.; Wilkins, A. [Univ. of Waikato, Hamilton (New Zealand); Kim, N. [Environment Waikato, Hamilton (New Zealand)

2003-07-01

There is growing awareness in New Zealand that a proportion of horticultural land has been contaminated with trace elements (As, Cd, Cu, Pb, Zn) and organochlorine pesticides (e.g. DDT, DDD, DDE and dieldrin) as a result of historic applications of agrichemicals (including pesticides, fertilisers and soil amendments). We have recently reported a significant negative correlation between Cu concentrations and the ratio of DDE to DDT in Auckland pip and stonefruit orchard soils and provided evidence that elevated levels of Cu in orchard soils were impacting on microbial activity. The specific objective of the study reported here was to determine whether the DDE:DDT ratio and Cu were similarly correlated in another fruit growing region of New Zealand, namely the Waikato region. DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) was widely used in the New Zealand to control chewing insects. DDT is degraded in soil by biotic and abiotic processes to form DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane) and DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)etylene). Cu is the active ingredient in a wide range of current and historic fungicides. Elevated levels of copper in horticultural soils have been demonstrated to negatively impact on the soil microbial community. Orchards (n=7) were sampled as part of a larger survey investigating agrichemical residues (organochlorine pesticides and trace elements) in cropping soils in the Waikato region, New Zealand. ?DDT concentrations in orchard soils ranged from 0.37 to 34.5 mg kg{sup -1}. There was a significant negative correlation (-0.84, p<0.02) between Cu concentration (242 to 523 mg kg{sup -1}) and the ratio of p,p'-DDE to p,p'-DDT (0.8 to 3.6) in pip and stonefruit orchard soils. The ratio of soil microbial carbon to soil carbon (% C{sub mic}/Org-C) in orchard soils decreased compared to reference soils. The microbial metabolic quotient aCO2 increased in orchard soils compared to reference soils. These results indicate

Negative temperature coefficient of the action of DDT in a sense organ

NARCIS (Netherlands)

Bercken, J. van den; Akkermans, L.M.A.

1972-01-01

DDT induced repetitive spontaneuos activity inthe afferent nerve fibers of the lateral-line organ of the clawed toad, Xenopus laevis. The action of DDT increased markedly with lowered temperature. This temperature-effect was easily reversible. The results demonstrate that DDT has a definite negative

DDT degradation efficiency and ecotoxicological effects of two types of nano-sized zero-valent iron (nZVI) in water and soil.

Science.gov (United States)

El-Temsah, Yehia S; Sevcu, Alena; Bobcikova, Katerina; Cernik, Miroslav; Joner, Erik J

2016-02-01

Nano-scale zero-valent iron (nZVI) has been conceived for cost-efficient degradation of chlorinated pollutants in soil as an alternative to e.g permeable reactive barriers or excavation. Little is however known about its efficiency in degradation of the ubiquitous environmental pollutant DDT and its secondary effects on organisms. Here, two types of nZVI (type B made using precipitation with borohydride, and type T produced by gas phase reduction of iron oxides under H2) were compared for efficiency in degradation of DDT in water and in a historically (>45 years) contaminated soil (24 mg kg(-1) DDT). Further, the ecotoxicity of soil and water was tested on plants (barley and flax), earthworms (Eisenia fetida), ostracods (Heterocypris incongruens), and bacteria (Escherichia coli). Both types of nZVI effectively degraded DDT in water, but showed lower degradation of aged DDT in soil. Both types of nZVI had negative impact on the tested organisms, with nZVI-T giving least adverse effects. Negative effects were mostly due to oxidation of nZVI, resulting in O2 consumption and excess Fe(II) in water and soil. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Situation report: Heavy DDT contamination at Wheeler National Wildlife Refuge

Science.gov (United States)

Fleming, W.J.; Atkeson, T.Z.

1980-01-01

A DDT manufacturing plant that operated on the Redstone Arsenal near Huntsville, Alabama discharged DDT-Iaden effluent from 1947 to 1970 into a creek on Wheeler National Wildlife Refuge. Seven to 9 years after the plant closed, high DDT, DDE, and DDD levels were reported in soils, river sediments, and fish in the area. Eleven of 27 mallards (Anas platyrhynchos) collected on the Refuge during February 1979 had carcass DDE residues that exceeded levels associated with eggshell thinning. DDE residues in a smaller number of mallards exceeded levels associated with egg breakage, poor hatchability, and abnormal hehavior and poor survival of offspring. Several avian species have disappeared from the Refuge since 1950, probably due to both industrial discharges of DDT from the plant and insecticidal use of DDT in the area. The contamination still presents a threat to herons, waterfowl, and raptors including occasional wintering or migrant eagles (Haliaeetus leucocephalus), and probably many other avian species. A maternity colony of endangered gray bats (Myotis grisescens) is also threatened by this contamination.

The long-term effects of DDT exposure on semen, fertility, and sexual function of malaria vector-control workers in Limpopo Province, South Africa

International Nuclear Information System (INIS)

Dalvie, M.A.; Myers, J.E.; Thompson, M.L.; Robins, T.G.; Dyer, Silke; Riebow, John; Molekwa, Josef; Jeebhay, Mohamed; Millar, Robert; Kruger, Phillip

2004-01-01

Hormonally active chemicals in the environment such as DDT have been associated with declining male reproductive health, especially semen quality. A cross-sectional study of 60 workers was performed near the Malaria Control Center (MCC) in Tzaneen, Limpopo Province, South Africa. Tests included a questionnaire (sexual function, fertility, and job history), a physical examination of the reproductive system, and semen analysis (produced via coitus interruptus or masturbation). Sperm count, density, and motility using the World Health Organization criteria and morphology using the strict Tygerberg criteria were determined. Serum o'p' and p'p' isomers of DDE, DDT, and DDD were measured. Forty-eight (81.0%) participants produced a semen sample, while all completed the questionnaires and physical examination. The mean sperm count was 93.8±130.3 million, and sperm density was 74.6±85.1 million/mL. The mean normal morphology score was 2.5±1.8% of subjects. Eighty-four percent of morphology scores were below either the WHO or the Tygerberg criteria, with the highest individual score being 6%. Self-perceived current problems with sexual function ranged between 10% and 20%. The most prevalent genital abnormality was abnormal testis disposition at 71%. There were few significant associations between DDT exposure measures (measured as years worked at MCC and serum DDT) and reproductive outcomes. p'p'-DDT was negatively associated with semen count (β-circumflex=-3.7±1.7; P=0.04; R 2 =0.05 adjusted for age, abstinence, physical abnormality, and fever in last 2 months). While the semen quality in the study was less than normal, no strong evidence for a DDT effect was found

New DDT inputs after 30 years of prohibition in Spain. A case study in agricultural soils from south-western Spain

International Nuclear Information System (INIS)

Munoz-Arnanz, Juan; Jimenez, Begona

2011-01-01

This study provides information on the current status of contamination by DDT in agricultural soils in south-western Spain. A recent use of technical DDT in at least 17% of the soils was found based on the values ( p,p ' /p,p ' =[p,p ' -DDE+p,p ' -DDD]/[p,p ' -DDT]. According to the ratio R o,p ' /p,p ' =[o,p ' -DDT]/[p,p ' -DDT], a dicofol type contamination was detected in about 27% of the soils. A wide range of concentrations was observed (0.08-11.1 ng/g d.w.) regardless of the type of crop soil. Enantiomeric fractions (EFs), based on the chiral analysis of o,p'-DDT residues differed from the racemic value (0.500) in most soils but they were not correlated with the study variables [DDTs], SOM, R p,p ' /p,p ' and R o,p ' /p,p ' . Given the health risks posed by DDT, our findings support how the environmental control of legacy pollutants such as DDT cannot be neglected. - Highlights: → Fresh technical DDT inputs detected in agricultural soils. → A Dicofol type contamination was found in agricultural soils from south-western Spain. → EFs of o,p'-DDT do not provide a good measure for overall DDT degradation. - Based on the isomeric ratio R p,p ' /p,p ' , a plausible recent input of technical DDT was found in agricultural soils from south-western Spain after more than 30 years of DDT ban.

Effects of nano-sized zero-valent iron (nZVI) on DDT degradation in soil and its toxicity to collembola and ostracods.

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El-Temsah, Yehia S; Joner, Erik J

2013-06-01

Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg(-1)) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg(-1)). These were incubated with 1 or 10 g nZVI kg(-1), and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg(-1) was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigation of 12Kh1MF steel resistance to brittle fractures

International Nuclear Information System (INIS)

Bologov, G.A.; Rushchits, T.Yu.

1977-01-01

The metal of hot-rolled steam pipe made of 12Kh1MF steel, which has been subjected to thermal treatment under laboratory conditions, and metal samples from acting steam pipes after different exploitation periods at 510-565 deg C have been investigated. The dependence of impact viscosity and its constituents on conditions of thermal treatment has been established. The energy consumed by the developing crack has been used as an impact viscosity criterion. Appropriate thermal treatment is capable of rehabilitating the impact viscosity of embrittled metal. Cold plastic deformation increases crack propagation rate in the initial metal and promotes embrittlement during exploitation. Ageing of the working metal reduces its capacity of stopping the developing crack and shifts the temperature threshold of brittleness towards positive temperature

Persistence and mobility of the 14C-DDT organic chlorine insecticide in soil

International Nuclear Information System (INIS)

Andrea, M.M. de; Ruegg, E.F.; Tomita, R.Y.

1988-01-01

Data from temperate regions considered DDT as highly persistent. This experiment was set to study what is occurring with DDT residues under the Brazilian tropical environment. Tests with 14 C-DDT are being conducted in soil columns in the field, and in the laboratory at ambient temperature and at 34 0 C. It will cover a two years period. Quantification of 14 C is done by liquid scintillation counting of the organic extracts and 14 CO 2 from wet-combustion. Results up to 9 months show that disappearance of the compound is enhanced in the field, and even after 6 months very little amounts of the insecticide leached to the deeper sections of the soils columns. (author) [pt

Special AT rich-binding1 protein (SATB1) in malignant T cells

DEFF Research Database (Denmark)

Fredholm, Simon; Willerslev-Olsen, Andreas; Met, Özcan

2018-01-01

Deficient expression of Suppressor Special AT-rich Binding-1 (SATB1) hampers thymocyte development and results in inept T cell lineages. Recent data implicate dysregulated SATB1 expression in the pathogenesis of mycosis fungoides (MF), the most frequent variant of cutaneous T cell lymphoma (CTCL......) whereas increased SATB1 expression had the opposite effect indicating that the mir-155 target SATB1 is a repressor of IL-5 and IL-9 in malignant T cells. In accordance, inhibition of STAT5, and its upstream activator Janus Kinase-3 (Jak3), triggered increased SATB1 expression and a concomitant suppression...

Effects of amendments on the uptake and distribution of DDT in Cucurbita pepo ssp pepo plants

International Nuclear Information System (INIS)

Whitfield Aslund, Melissa L.; Lunney, Alissa I.; Rutter, Allison; Zeeb, Barbara A.

2010-01-01

The effects of soil amendments on the phytoextraction of ΣDDT (DDT + DDD + DDE) from soil ([ΣDDT] ∼ 1500 ng/g) by a pumpkin variety of Cucurbita pepo ssp pepo were tested and the patterns of ΣDDT storage throughout the plant shoot were examined. The soil amendments did not increase the total amount of ΣDDT extracted into plant shoots, but new information about ΣDDT distribution in the plants was obtained. As observed previously, the ΣDDT concentration in plant leaves (mean 290 ng/g) was significantly lower than in plant stems (mean 2600 ng/g). Further analysis revealed that ΣDDT composition was consistent throughout the plant shoot and that ΣDDT concentration in leaves and stems decreased exponentially as distance from the root increased, which was previously unknown. This new information about the patterns of ΣDDT uptake and translocation within pumpkin plants highlights the need for appropriate plant sampling strategies in future POPs phytoextraction research. - Patterns of ΣDDT storage in a pumpkin plant are elucidated and specific surfactant and mycorrhizal soil amendments did not increase the total amount of ΣDDT phytoextracted into plant shoots.

Maintenance and neuronal cell differentiation of neural stem cells C17.2 correlated to medium availability sets design criteria in microfluidic systems.

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Bu Wang

Full Text Available BACKGROUND: Neural stem cells (NSCs play an important role in developing potential cell-based therapeutics for neurodegenerative disease. Microfluidics has proven a powerful tool in mechanistic studies of NSC differentiation. However, NSCs are prone to differentiate when the nutrients are limited, which occurs unfavorable by fast medium consumption in miniaturized culture environment. For mechanistic studies of NSCs in microfluidics, it is vital that neuronal cell differentiation is triggered by controlled factors only. Thus, we studied the correlation between available cell medium and spontaneous neuronal cell differentiation of C17.2 NSCs in standard culture medium, and proposed the necessary microfluidic design criteria to prevent undesirable cell phenotype changes. METHODOLOGY/PRINCIPAL FINDINGS: A series of microchannels with specific geometric parameters were designed to provide different amount of medium to the cells over time. A medium factor (MF, defined as the volume of stem cell culture medium divided by total number of cells at seeding and number of hours between medium replacement successfully correlated the amount of medium available to each cell averaged over time to neuronal cell differentiation. MF smaller than 8.3×10(4 µm3/cell⋅hour produced significant neuronal cell differentiation marked by cell morphological change and significantly more cells with positive β-tubulin-III and MAP2 staining than the control. When MF was equal or greater than 8.3×10(4 µm3/cell⋅hour, minimal spontaneous neuronal cell differentiation happened relative to the control. MF had minimal relation with the average neurite length. SIGNIFICANCE: MFs can be controlled easily to maintain the stem cell status of C17.2 NSCs or to induce spontaneous neuronal cell differentiation in standard stem cell culture medium. This finding is useful in designing microfluidic culture platforms for controllable NSC maintenance and differentiation. This study also

Ionosphere research with a HF/MF cubesat radio instrument

Science.gov (United States)

Kallio, Esa; Aikio, Anita; Alho, Markku; Fontell, Mathias; Harri, Ari-Matti; Kauristie, Kirsti; Kestilä, Antti; Koskimaa, Petri; Mäkelä, Jakke; Mäkelä, Miika; Turunen, Esa; Vanhamäki, Heikki; Verronen, Pekka

2017-04-01

New technology provides new possibilities to study geospace and 3D ionosphere by using spacecraft and computer simulations. A type of nanosatellites, CubeSats, provide a cost effective possibility to provide in-situ measurements in the ionosphere. Moreover, combined CubeSat observations with ground-based observations gives a new view on auroras and associated electromagnetic phenomena. Especially joint and active CubeSat - ground based observation campaigns enable the possibility of studying the 3D structure of the ionosphere. Furthermore using several CubeSats to form satellite constellations enables much higher temporal resolution. At the same time, increasing computation capacity has made it possible to perform simulations where properties of the ionosphere, such as propagation of the electromagnetic waves in the medium frequency, MF (0.3-3 MHz) and high frequency, HF (3-30 MHz), ranges is based on a 3D ionospheric model and on first-principles modelling. Electromagnetic waves at those frequencies are strongly affected by ionospheric electrons and, consequently, those frequencies can be used for studying the plasma. On the other hand, even if the ionosphere originally enables long-range telecommunication at MF and HF frequencies, the frequent occurrence of spatiotemporal variations in the ionosphere disturbs communication channels, especially at high latitudes. Therefore, study of the MF and HF waves in the ionosphere has both a strong science and technology interests. We introduce recently developed simulation models as well as measuring principles and techniques to investigate the arctic ionosphere by a polar orbiting CubeSat whose novel AM radio instrument measures HF and MF waves. The cubesat, which contains also a white light aurora camera, is planned to be launched in late 2017 (http://www.suomi100satelliitti.fi/eng). The new models are (1) a 3D ray tracing model and (2) a 3D full kinetic electromagnetic simulation. We also introduce how combining of the

Biological responses of human solid tumor cells to X-ray irradiation within a 1.5-Tesla magnetic field generated by a magnetic resonance imaging-linear accelerator.

Science.gov (United States)

Wang, Li; Hoogcarspel, Stan Jelle; Wen, Zhifei; van Vulpen, Marco; Molkentine, David P; Kok, Jan; Lin, Steven H; Broekhuizen, Roel; Ang, Kie-Kian; Bovenschen, Niels; Raaymakers, Bas W; Frank, Steven J

2016-10-01

Devices that combine magnetic resonance imaging with linear accelerators (MRL) represent a novel tool for MR-guided radiotherapy. However, whether magnetic fields (MFs) generated by these devices affect the radiosensitivity of tumors is unknown. We investigated the influence of a 1.5-T MF on cell viability and radioresponse of human solid tumors. Human head/neck cancer and lung cancer cells were exposed to single or fractionated 6-MV X-ray radiation; effects of the MF on cell viability were determined by cell plating efficiency and on radioresponsiveness by clonogenic cell survival. Doses needed to reduce the fraction of surviving cells to 37% of the initial value (D0s) were calculated for multiple exposures to MF and radiation. Results were analyzed using Student's t-tests. Cell viability was no different after single or multiple exposures to MRL than after exposure to a conventional linear accelerator (Linac, without MR-generated MF) in 12 of 15 experiments (all P > 0.05). Single or multiple exposures to MF had no influence on cell radioresponse (all P > 0.05). Cells treated up to four times with an MRL or a Linac further showed no changes in D0s with MF versus without MF (all P > 0.05). In conclusion, MF within the MRL does not seem to affect in vitro tumor radioresponsiveness as compared with a conventional Linac. Bioelectromagnetics. 37:471-480, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Laboratory evaluation of the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae.

Science.gov (United States)

Evans, R G

1993-09-01

In a laboratory study, the irritancy of bendiocarb, lambda-cyhalothrin and DDT to Anopheles gambiae was evaluated at field, 1/3 field and 1/10 field rates using WHO conical exposure chambers and excito-repellency test boxes. Bendiocarb was the least irritant insecticide at all rates, inducing levels of takeoff, flight and exiting behavior similar to those of a distilled water control treatment. Of those mosquitoes introduced to the bendiocarb-treated boxes, not more than 1% exited and survived at any dose rate. Lambda-cyhalothrin and DDT were highly irritant to An. gambiae, inducing a strong stimulation to take off and fly and also a high level of exiting. Exiting-survival rates associated with lambda-cyhalothrin and DDT were between 15 and 51%. The relevance of these findings to the control of mosquito populations and the prevention of malaria transmission is discussed.

Toxic effects of male Perna viridis gonad exposed to BaP, DDT and their mixture: A metabolomic and proteomic study of the underlying mechanism.

Science.gov (United States)

Song, Qinqin; Zheng, Pengfei; Qiu, Liguo; Jiang, Xiu; Zhao, Hongwei; Zhou, Hailong; Han, Qian; Diao, Xiaoping

2016-01-05

Benzo(a)pyrene and dichlorodiphenyltrichloroethane are typical persistent organic pollutants, and also the widespread environmental estrogens with known toxicity towards green mussels Perna viridis. In this study, the toxicological effects of BaP and DDT and their mixture were assessed in green mussel gonads using proteomic and metabolomic approaches. Metabolomics by NMR spectroscopy revealed that BaP did not show obvious metabolite changes in the gonad of male green mussel. DDT mainly caused some disturbance of osmotic regulation and energy metabolism by changing BCAAs, alanine, threonine, arginine, etc., unknown metabolite (3.53 ppm), glycine, homarine and ATP at different levels. However, the mixture of BaP and DDT mainly caused some disturbance in osmotic regulation and energy metabolism by differentially altering branched chain amino acids, glutamate, alanine, arginine, unknown metabolite (3.53 ppm), glycine, 4-aminobutyrate, dimethylglycine, homarine and ATP. The results suggest that DDT alone may cause most of metabolites changes in the mixture exposed male mussel gonad, and the results also show that the male P. viridis gonad was more sensitive to DDT than BaP exposures. Proteomic study showed that BaP, DDT and their mixture may have different modes of action. Proteomic responses revealed that BaP induced signal transduction, oxidative stress, spermatogenesis, etc. in the male green mussel gonad; whereas DDT exposure altered proteins that were associated with signal transduction, oxidative stress, cytoskeleton and cell structure, cellular organization, energy metabolism, etc. However, the mixture of BaP and DDT affected proteins related to cytoskeleton and cell structure, oxidative stress, cellular organization, etc. This research demonstrated that metabolomic and proteomic approaches could better elucidate the underlying mechanism of environmental pollutants gonad toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Predictors of Plasma DDT and DDE Concentrations among Women Exposed to Indoor Residual Spraying for Malaria Control in the South African Study of Women and Babies (SOWB)

Science.gov (United States)

Bornman, Riana M.S.; Archer, Janet I.; Kudumu, Mwenda O.; Travlos, Gregory S.; Wilson, Ralph E.; Longnecker, Matthew P.

2014-01-01

Background: Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. Methods: The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. Results: Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. Conclusion: The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education

Smooth muscle antibodies and type 1 autoimmune hepatitis.

Science.gov (United States)

Muratori, Paolo; Muratori, Luigi; Agostinelli, Daniela; Pappas, Georgios; Veronesi, Lorenza; Granito, Alessandro; Cassani, Fabio; Terlizzi, Paolo; Lenzi, Marco; Bianchi, Francesco B

2002-12-01

Smooth muscle antibodies (SMA) characterize type 1 autoimmune hepatitis. Our aim was to evaluate sensitivity and specificity of different immunofluorescence substrates for the detection of SMA. Sera from 55 patients with type 1 AIH 20 with primary biliary cirrhosis, 20 with HCV-related chronic hepatitis and 25 blood donors were studied for SMA and anti-microfilaments reactivity by immunofluorescence on rat tissue sections, cultured fibroblasts and commercially available HEp-2 cells (collectively revealing the so called anti-actin pattern), and for the XR1 system by counterimmunoelectrophoresis. SMA was classified on the basis of its immunofluorescence pattern (V--vessels, G--glomerular, T--tubular). As further control group, we studied 26 patients with a diagnosis other than AIH, selected on the basis of a SMA-non-T/XR1 positivity. In patients with AIH the SMA-T pattern on rodent tissue, and anti-MF on fibroblasts and on HEp-2 cells were present in 80, 82 and 80%, respectively. Five out of 11 SMA-non T positive AIH patients were anti-MF positive. None of the pathological and healthy controls was positive for SMA-T or anti-MF reactivity. XR1 system was present in 84% of AIH patients and in 5% of pathological controls (p = 0.01). Two out of 26 SMA-non-T/XR1 positive sera were positive for anti-MF by fibroblasts and HEp-2 cells. A significant correlation was found between SMA-T pattern and anti-MF reactivity; no correlation was found between XR1 system and SMA-T pattern or anti-MF reactivity. SMA-T pattern is highly sensitive and specific first diagnostic test for type 1 AIH; anti-MF can be used as additional tool for the diagnosis, particularly when, despite the absence of the SMA-T pattern, AIH is strongly suspected.

Application of sewage sludge and intermittent aeration strategy to the bioremediation of DDT- and HCH-contaminated soil.

Science.gov (United States)

Liang, Qi; Lei, Mei; Chen, Tongbin; Yang, Jun; Wan, Xiaoming; Yang, Sucai

2014-08-01

Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) contaminated soil was investigated in bench scale experiments, and intermittent aeration strategy was also used in this study to form an anaerobic-aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%-80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to 218 g/kg, and it could also introduce efficient degradation microbes to soil, including Pseudomonas sp., Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH, and anaerobic removal rates of β-HCH, o,p'-DDT and p,p'-DDT accounted for more than 50% of the total removal rates, but the content of α-HCH declined more in the aerobic phase. Copyright © 2014. Published by Elsevier B.V.

Determination of n-octanol/water partition coefficient for DDT-related compounds by RP-HPLC with a novel dual-point retention time correction.

Science.gov (United States)

Han, Shu-ying; Qiao, Jun-qin; Zhang, Yun-yang; Yang, Li-li; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

2011-03-01

n-Octanol/water partition coefficients (P) for DDTs and dicofol were determined by reversed-phase high performance liquid chromatography (RP-HPLC) on a C(18) column using methanol-water mixture as mobile phase. A dual-point retention time correction (DP-RTC) was proposed to rectify chromatographic retention time (t(R)) shift resulted from stationary phase aging. Based on this correction, the relationship between logP and logk(w), the logarithm of the retention factor extrapolated to pure water, was investigated for a set of 12 benzene homologues and DDT-related compounds with reliable experimental P as model compounds. A linear regression logP=(1.10±0.04) logk(w) - (0.60±0.17) was established with correlation coefficient R(2) of 0.988, cross-validated correlation coefficient R(cv)(2) of 0.983 and standard deviation (SD) of 0.156. This model was further validated using four verification compounds, naphthalene, biphenyl, 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (p,p'-DDD) and 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (p,p'-DDE) with similar structure to DDT. The RP-HPLC-determined P values showed good consistency with shake-flask (SFM) or slow-stirring (SSM) results, especially for highly hydrophobic compounds with logP in the range of 4-7. Then, the P values for five DDT-related compounds, 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1,1-trichloroethane (o,p'-DDT), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethane (o,p'-DDD), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethene (o,p'-DDE), and 2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol (dicofol) and its main degradation product 4,4'-dichlorobenzophenone (p,p'-DBP) were evaluated by the improved RP-HPLC method for the first time. The excellent precision with SD less than 0.03 proved that the novel DP-RTC protocol can significantly increases the determination accuracy and reliability of P by RP-HPLC. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of Soil Oxygen Conditions and Soil pH on Remediation of DDT-contaminated Soil by Laccase from White Rot Fungi

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Yuechun Zhao

2010-04-01

Full Text Available High residues of DDT in agricultural soils are of concern because they present serious threats to food security and human health. This article focuses on remediation of DDT-contaminated soil using laccase under different soil oxygen and soil pH conditions. The laboratory experiment results showed significant effects of soil oxygen conditions and soil pH on remediation of DDT-contaminated soil by laccase at the end of a 25-d incubation period. This study found the positive correlation between the concentration of oxygen in soil and the degradation of DDT by laccase. The residue of DDTs in soil under the atmosphere of oxygen decreased by 28.1% compared with the atmosphere of nitrogen at the end of the incubation with laccase. A similar pattern was observed in the remediation of DDT-contaminated soil by laccase under different flooding conditions, the higher the concentrations of oxygen in soil, the lower the residues of four DDT components and DDTs in soils. The residue of DDTs in the nonflooding soil declined by 16.7% compared to the flooded soil at the end of the incubation. The residues of DDTs in soils treated with laccase were lower in the pH range 2.5–4.5.

Human T-cell lymphotropic virus type 1 provirus and phylogenetic analysis in patients with mycosis fungoides and their family relatives.

Science.gov (United States)

Shohat, M; Shohat, B; Mimouni, D; Pauli, G; Ellerbrok, H; David, M; Hodak, E

2006-08-01

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma of unknown aetiology. A pathogenic role of human T-cell lymphotropic virus type 1 (HTLV-1) has been suggested but remains controversial. To determine whether MF is linked to HTLV-1. Blood samples were collected from 60 patients, 15 family relatives of patients with MF (MFRs), 20 healthy controls and 10 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The presence of HTLV-1 antibodies in serum was tested by the Western blot rp21e-enhanced test. DNA was extracted from the blood with the Qiagen blood kit. We used 500 ng of DNA either in conventional HTLV-1-specific polymerase chain reaction (PCR) or in real-time PCR using primers sk43 and sk44 together with a tax-specific fluorescent probe. In Western blot, antibodies against three to four HTLV-1 antigens were detected in 52% of patients with MF. All of the patients with HAM/TSP were positive, while only 7% of the MFRs and none of the 20 healthy controls reacted with HTLV-1 antigens in Western blot. One of 60 patients with MF and one of 15 MFRs were positive in HTLV-1 PCR. These two PCR-positive samples which were quantified in real-time PCR showed that fewer than five in 10(6) cells were HTLV-1 infected. We succeeded in amplifying and sequencing the 5' end of the provirus from the blood of the PCR-positive MFR by seminested PCR. A positive result was also obtained in this test. Phylogenetic tree analyses revealed a high homology of this sequence with other HTLV-1 sequences from the Middle East. The above PCR-positive MFR was the brother of a PCR-negative patient with MF. These findings demonstrate that HTLV-1 is probably not the aetiological agent of MF. However, it may play a role in immunosuppression and in the spreading of the disease.

Negative regulation of AMP-activated protein kinase (AMPK) activity by macrophage migration inhibitory factor (MIF) family members in non-small cell lung carcinomas.

Science.gov (United States)

Brock, Stephanie E; Rendon, Beatriz E; Yaddanapudi, Kavitha; Mitchell, Robert A

2012-11-02

AMP-activated protein kinase (AMPK) is a nutrient- and metabolic stress-sensing enzyme activated by the tumor suppressor kinase, LKB1. Because macrophage migration inhibitory factor (MIF) and its functional homolog, d-dopachrome tautomerase (d-DT), have protumorigenic functions in non-small cell lung carcinomas (NSCLCs) but have AMPK-activating properties in nonmalignant cell types, we set out to investigate this apparent paradox. Our data now suggest that, in contrast to MIF and d-DTs AMPK-activating properties in nontransformed cells, MIF and d-DT act cooperatively to inhibit steady-state phosphorylation and activation of AMPK in LKB1 wild type and LKB1 mutant human NSCLC cell lines. Our data further indicate that MIF and d-DT, acting through their shared cell surface receptor, CD74, antagonize NSCLC AMPK activation by maintaining glucose uptake, ATP production, and redox balance, resulting in reduced Ca(2+)/calmodulin-dependent kinase kinase β-dependent AMPK activation. Combined, these studies indicate that MIF and d-DT cooperate to inhibit AMPK activation in an LKB1-independent manner.

Potencial de biodegradación de DDT y sus metabolitos en suelos agrícolas de Chinandega

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Carlos E. Noguera Solís

2008-04-01

Full Text Available LA PRESENTE INVESTIGACIÓN EVALUÓ EL POTENCIAL DE BIODEGRADACIÓN DEL 1,1,1-Tricloro- 2,2-bis(4-clorofeniletano (DDT y sus metabolitos en suelos agrícolas pertenecientes a fincas del municipio de El Viejo, Chinandega, a través de dos ensayos: ensayo de biodegradación ex situ y ensayo de búsqueda e identificación de microorganismos capaces de biodegradar DDT. En el primer ensayo se determinó el porcentajede biodegradación, bajo condiciones idóneas, durante un período de 100 días en diferentes lotes de suelo con diferentes aditivos (cachaza y estiércol a través de la aplicación de cepas microbianas comerciales Environoc 201®. De ello se obtuvo como resultado un porcentaje de biodegradación mayor para el lote que no presentaba aditivos orgánicos, siendo éste de 23,92%. En el ensayo de búsqueda eidentificación de bacterias se lograron aislar e identificar cepas microbianas nativas de los suelos agrícolas objeto de estudio utilizando medios de cultivo con DDT como única fuente de carbono y energía. Como resultado se lograron identificar los siguientes microorganismos: Pseudomonas sp., Streptomyces sp., Phanerochaetechrysosporium y levaduras.

Variation effect on the insecticide activity of DDT analogues. A chemometric approach

Science.gov (United States)

Itoh, S.; Nagashima, U.

2002-08-01

We investigated a variation effect on the insecticide activity of DDT analogues by using the first principles electronic structure calculations and the neural network analysis. It has been found that the charge distribution at the specific atomic sites in the DDT molecule is related to their toxicity. This approach can contribute to designing a new insecticide and a new harmlessness process of the DDT analogues.

Study of Ionospheric Indexes T and MF2 related to R12 for Solar Cycles 19-21

Science.gov (United States)

Villanueva, Lucia

2013-04-01

Modern worldwide communications are mainly based on satellite systems, remote communication networks, and advanced technologies. The most important space weather "meteorological" events produce negative effects on signal transmissions. Magnetic storm conditions that follow coronal mass ejections are particularly of great importance for radio communication at HF frequencies (3-30 MHz range), because the Ionization increase (or decrease), significantly over (or below), the Average Values. Nowadays new technologies make possible to establish Geophysical Observatories and monitor the sun almost in real time giving information about geomagnetic indices. Space Weather programs have interesting software predictions of foF2 producing maps and plots, every some minutes. The Average Values of the ionospheric parameters mainly depend on the position, hour, season and the phase of the 11-year cycle of the solar activity. Around 1990´s several ionospheric indexes were suggested to better predict the state of the foF2 monthly media, as: IF2, G, T and MF2, based on foF2 data from different latitude ionospheric observatories. They really show better seasonal changes than monthly solar indexes of solar flux F10.7 or the international sunspot numbers Ri. The main purpose of this paper is to present an analogic model for the ionospheric index MF2, to establish the average long term predictions of this index. Changes of phase from one cycle to the other of one component of the model is found to fit the data. The usefulness of this model could be the prediction of the ionospheric normal conditions for one entire solar cycle having just the prediction of the maximum of the next smooth sunspot number R12. In this presentation, comparisons of the Australian T index and and the Mikhailov MF2 index show an hysteresis variation with the solar monthly index Ri, such dependence is quite well represented by a polynomial fit of degree 6 for rising and decaying fases for solar cycles 19, 20 and

Efecto tóxico de DDT y endosulfan en postlarvas de camarón blanco, Litopenaeus vannamei (Decapoda:Penaeidaede Chiapas,México

Directory of Open Access Journals (Sweden)

Vicente Castro-Castro

2005-06-01

sensitive to both compounds and DDT was thrice as toxic as endosulfan. Growth rate decreased 50 % and 80 % with endosulfan and DDT, respectively, at the experimental pestice concentration.The low resistance of postlarvae to DDT and endosulfan suggests that additional inflow of these pesticides into the aquatic system could affect the rate of shrimp production in the area. Rev. Biol. Trop. 53(1-2:141-151. Epub 2005 Jun 24

Study of DDT and its derivatives DDD, DDE adsorption and degradation over Fe-SBA-15 at low temperature

Institute of Scientific and Technical Information of China (English)

Hailin Wang; Hua Tian; Zhengping Hao

2012-01-01

Mesoporous SBA-15 with different Fe2O3 loading were synthesized by an in-situ coating progress for removals of dichlorodiphenyltrichloroethane(DDT)and its derivatives,i.e.,1,1-dichloro-2,2-bis-(p-chlorophenyl)ethane(DDD)and 1,l-dichloro-2,2-bis-(4-chloro -phenyl)ethane(DDE).The results from XRD(X-ray diffractometer),TEM(transmission electron microscopy)indicated that the iron could be well dispersed on SBA-15 within 6 wt.% Fe2O3 loading.Nitrogen adsorption-desorption tests indicated that the synthesized materials were characterized by ordered meso-structure,high surface area and large pore volume.DDTs were removed from aqueous media in 12-hr treatment and high removal efficiency of DDTs was achieved at over 94%.DDTs could be completely degraded at 350℃ under the existence of SBA-15 with 4 wt.% Fe2O3 loading.The final degradation products of DDT were dichlorobenzophenone (DCB)and bis-(4-chloro-phenyl)methane(DDM),suggesting a complete dechlorination from trichloromethyl.

糖尿病视网膜1期病变多焦视网膜图变化分析%A Study in the Changes of mfERG in Stage 1 Diabetic Retinopathyn

Institute of Scientific and Technical Information of China (English)

张聪; 刘哲丽; 徐丽; 郭敬斌

2009-01-01

目的 通过检测糖尿病视网膜1期病变患者多焦视网膜电图(multifocal electroretino-gram,mfERG),评价1期糖尿病视网膜病变患者早期视功能的变化.方法 检测正常对照组31只眼,1期糖尿病视网膜病变组46只眼的mtERG在视野30°的测试范围内6个不同离心度的环形区N1、P1波潜伏期、P1波反应密度改变.结果 在视野30°的测试范围内6个不同离心度的环形区,1期糖尿病视网膜病变组(DR组)与正常对照组之间比较N1、P1波潜伏期显著延长;环1、2区DR组与正常对照组之间比较P1波反应密度显著降低.结论 尚未出现肉眼可见眼底改变的1期糖尿病视网膜病变即可出现视功能的异常,mfERG能够定量的检测1期糖尿病视网膜病变的局部视功能变化,为糖尿病视网膜病变的早期诊断提供有效方法.%Objective To investigate the changes of retinal function in stage 1 of diabetic retinopathy detected by multifoeal electroretinogram (mfERG).Methods The responses of mfERG were recorded and analyzed from eyes of 31 normal control subjects and 46 diabetic patients with stage 1 of diabetic retinopathy. Results In eyes of diabetic patients with stage 1 of diabetic retinopathy (DR), the lateneies of N1, P1 were delayed obviously compared to normal control subjects, in the field of about 30 degrees of six rings with different eccentricities; the response densities of the P1 ring1, 2 was significantly decreased in diabetic patients with stagel of diabetic retinopathy compared to normal control subjects.Conclusions The abnormalities of retinal function may occur in stagel of diabetic retinopathy, when there is no abnormality of ocular fundus.As a new objective and quantitative examination for visual function, mfERG may be valuable in early diagnosis of diabetic retinopathy.

Present DDT and lindane indoor concentrations after extensive use of wood preservatives in attics in the past; Aktuelle DDT- und Lindan-Konzentrationen in Wohnraeumen nach intensivem Holzschutzmitteleinsatz auf Dachboeden in der Vergangenheit

Energy Technology Data Exchange (ETDEWEB)

Rosskamp, E.; Horn, W.; Ullrich, D.; Seifert, B. [Umweltbundesamt, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene

1999-12-01

In the former German Democratic Republic (GDR) the wood preservative Hylotox 59, which contained DDT and lindane as biocides, was used indoors until 1988. It was the aim of this study to determine the concentration levels of DDT and lindane in the air of attics, newly converted attic apartments or apartments situated immediately under attics which had been treated with Hylotox 59. In some cases dust and wood samples were examined, too. This study shows that concentrations of DDT and lindane of up to 4600 and 930 ng/m{sup 3} can be found in air of treated attics even more than 20 years after the application of wood preservatives. However, the median concentrations in recently converted attic apartments and apartments below an attic were much lower, namely 20 and 40 ng/m{sup 3}, respectively, for DDT and 5 and 20 ng/m{sup 3}, respectively, for lindane. Only some apartments showed DDT and lindane concentrations above 100 ng/m{sup 3}. In these cases biocides had been used directly in the apartment or there was a possibility for an air exchange between the attic and the rooms. Exposure of dwellers to DDT and lindane occurs mainly by inhalation. In addition, infants and small children who usually play on the floor may be exposed by contact with and intake of house dust. The maximum DDT content of house dust observed in the apartments under study was 200 mg/kg, with a median of 20 mg/kg. The lindane content of house dust reached only 9 mg/kg. The calculated exposure of a small child to DDT and lindane in house dust is far below the allowable daily intake (ADI) recommended by FAO/WHO. (orig.) [German] Die Biozide DDT und Lindan wurden in der ehemaligen DDR bis 1988 als Wirkstoffe im Holzschutzmittel Hylotox 59 auf Dachboeden und z.T. auch in Innenraeumen eingesetzt. Ziel dieser Untersuchungen war es, die Biozidbelastung der Raumluft und die von einigen Staub- und Holzproben in vormals Hylotox-behandelten Dachboeden, in Wohnungen direkt unter solchen Dachboeden sowie in

The effect of DDT and dieldrin on myelinated nerve fibres

NARCIS (Netherlands)

Bercken, J. van den

1972-01-01

The effects of the chlorinated hydrocarbon insecticides, DDT and dieldrin, on myelinated nerve fibres of the clawed toad, Xenopus laevis, were studied by recording compound action nerve fibres, and membrane potentials of single nodes of Ranvier. The effect of DDT (5 × 10−4 M) was found to be

In situ bioavailability of DDT and Hg in sediments of the Toce River (Lake Maggiore basin, Northern Italy): accumulation in benthic invertebrates and passive samplers.

Science.gov (United States)

Pisanello, Francesca; Marziali, Laura; Rosignoli, Federica; Poma, Giulia; Roscioli, Claudio; Pozzoni, Fiorenzo; Guzzella, Licia

2016-06-01

DDT and mercury (Hg) contamination in the Toce River (Northern Italy) was caused by a factory producing technical DDT and using a mercury-cell chlor-alkali plant. In this study, DDT and Hg contamination and bioavailability were assessed by using different approaches: (1) direct evaluation of sediment contamination, (2) assessment of bioaccumulation in native benthic invertebrates belonging to different taxonomic/functional groups, and (3) evaluation of the in situ bioavailability of DDT and Hg using passive samplers. Sampling sites were selected upstream and downstream the industrial plant along the river axis. Benthic invertebrates (Gammaridae, Heptageniidae, and Diptera) and sediments were collected in three seasons and analyzed for DDT and Hg content and the results were used to calculate the biota sediment accumulation factor (BSAF). Polyethylene passive samplers (PEs) for DDT and diffusive gradients in thin films (DGTs) for Hg were deployed in sediments to estimate the concentration of the toxicants in pore water. Analysis for (DDx) were performed using GC-MS. Accuracy was within ±30 % of the certified values and precision was >20 % relative standard deviation (RSD). Total mercury concentrations were determined using an automated Hg mercury analyzer. Precision was >5 % and accuracy was within ±10 % of certified values. The results of all the approaches (analysis of sediment, biota, and passive samplers) showed an increasing contamination from upstream to downstream sites. BSAF values revealed the bioavailability of both contaminants in the study sites, with values up to 49 for DDx and up to 3.1 for Hg. No correlation was found between values in sediments and the organisms. Concentrations calculated using passive samplers were correlated with values in benthic invertebrates, while no correlation was found with concentrations in sediments. Thus, direct analysis of toxicant in sediments does not provide a measurement of bioavailability. On the contrary

Safety and effectiveness of MF-59 adjuvanted influenza vaccines in children and adults.

Science.gov (United States)

Black, Steven

2015-06-08

The squalene oil-in-water emulsion MF-59 adjuvant was developed initially to enhance the immunogenicity of influenza vaccines in populations such as children and adults with known suboptimal response. Developed in the 1990s, it was initially licensed in Europe for use in seasonal influenza vaccine in the elderly. Since that time, both Avian and p2009H1N1 vaccines have also been developed. Overall, more than 30,000 individuals have participated in clinical trials of MF-59 adjuvanted vaccine and more than 160 million doses of licensed vaccine have been administered. Safety and effectiveness data from clinical trials and observation studies attest to the safety of MF-59 and to its ability to enhance the effectiveness of influenza vaccines in children and the elderly. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trace element and ΣDDT concentrations in horticultural soils from the Tasman, Waikato and Auckland regions of New Zealand

International Nuclear Information System (INIS)

Gaw, S.K.; Wilkins, A.L.; Kim, N.D.; Palmer, G.T.; Robinson, P.

2006-01-01

The long-term routine use of agrichemicals can result in elevated levels of trace elements and persistent organic pollutants in soils. Trace element concentrations and ΣDDT levels were measured in soil (0-7.5 cm) samples collected from horticultural and grazing properties in 3 regions of New Zealand (Auckland, Tasman and Waikato). Elevated levels of arsenic ( -1 ), cadmium ( -1 ), copper (5 to 523 mg kg -1 ), lead (5 to 243 mg kg -1 ) and ΣDDT ( -1 ) were detected in soils from all 3 regions. With the exception of cadmium and zinc, significantly higher levels of contaminants were generally detected in horticultural soils than in grazing soils. Our results have implications for the on-going use of agrichemicals as concentrations of cadmium, copper, tin and zinc in some samples exceeded ecotoxicity based soil criteria. The p,p'-DDE : DDT ratios indicate that the degradation of DDT in NZ horticultural soils may be inhibited by the co-contamination with trace elements

Biological transfer and loss of 36Cl-labeled DDT in an old-field ecosystem

International Nuclear Information System (INIS)

Peterle, T.J.

1979-01-01

An enclosed 10-acre old-field plot treated in June 1969, with chlorine-36 labeled DDT was sampled each year from 1969 through 1974 to monitor the fate of the insecticide in the soil and biota. In order to provide data on compartmentalization of DDT in the vegetation, invertebrates and vertebrates inhabiting the plot, sampling was carried out to estimate both body burdens of DDT and biomass of populations. Another aspect of this study, the determination of rates of accumulation of residues by invertebrates and vertebrates, has been reported previously (Forsyth and Peterle 1973; Forsyth et al. 1975; Peterle 1975). This report describes (a) temporal patterns of DDT residues in soil and biota from 1969 through 1974 and (b) quantities of DDT held in the soil and biotic compartments of the ecosystem. Part II of the report is concerned with translocation and accumulation of 14 C-DDT

International Advocacy against DDT and Other Public Health Insecticides for Malaria Control

Science.gov (United States)

2011-01-19

2010 Nov 15. 17. Betlem J. Importancia mundial de los resultados del proyecto : Programa Mundial sobre demonstracion y aumento de alterna- tivas...Demonstration of Sustainable Alternatives for Malaria Vector Control without the Use of DDT in Mexico and Central America”], Proyecto DDT/PNUMA/GEF/OPS [DDT...epidemiológico de la malaria en las comunidades de los proyectos demostrativos en Meso América. Presented at V Reunion del Comite Directivo “Programa

Susceptibilidad de Aedes aegypti a DDT, deltametrina y lambdacialotrina en Colombia Susceptibility of Aedes aegypti to DDT, deltamethrin, and lambda-cyhalothrin in Colombia

Directory of Open Access Journals (Sweden)

Liliana Santacoloma Varón

2010-01-01

Full Text Available OBJETIVOS: Evaluar el estado de susceptibilidad a insecticidas piretroides deltametrina y lambdacialotrina y al organoclorado DDT, e identificar los mecanismos bioquímicos asociados con resistencia en 13 poblaciones naturales de Aedes aegypti recolectadas en localidades de Colombia donde el dengue es un grave problema de salud pública. MÉTODOS: Se recolectaron y criaron en condiciones controladas formas inmaduras de diferentes criaderos naturales del vector para cada localidad. Con la generación F2 se realizaron bioensayos utilizando las metodologías OMS 1981 (papeles impregnados y CDC 1998 (botellas impregnadas. En las poblaciones con mortalidades compatibles con disminución de la susceptibilidad, se midieron los niveles de esterasas no específicas (ENE, oxidasas de función mixta (OFM y acetilcolinesterasa modificada (ACEM mediante pruebas colorimétricas. RESULTADOS: Todas las poblaciones del mosquito evaluadas evidenciaron resistencia al organoclorado DDT. En cuanto a los piretroides, se encontró resistencia generalizada a lambdacialotrina pero no a deltametrina. Los mecanismos bioquímicos de resistencia evaluados permitieron encontrar 7 de 11 poblaciones con ENE elevadas y una población con OFM incrementadas. CONCLUSIONES: Se descarta la resistencia cruzada de tipo fisiológico entre el DDT y lambdacialotrina en las poblaciones de A. aegypti evaluadas. La resistencia fisiológica a lambdacialotrina parece asociarse con el incremento de las ENE. El comportamiento diferencial en los niveles de susceptibilidad y los valores enzimáticos entre poblaciones se asociaron con la variabilidad genética y presión de selección química a nivel local.OBJECTIVES: To assess the susceptibility status of 13 natural populations of Aedes aegypti (collected from sites in Colombia where dengue is a serious public health problem to the pyrethroids, deltamethrin and lambda-cyhalothrin, and to the organochlorine, DDT, and to identify any biochemical

Exposure to 60-Hz magnetic fields and proliferation of human astrocytoma cells in vitro.

Science.gov (United States)

Wei, M; Guizzetti, M; Yost, M; Costa, L G

2000-02-01

Epidemiological studies have suggested that exposure to electric and magnetic fields (EMF) may be associated with an increased incidence of brain tumors, most notably astrocytomas. However, potential cellular or molecular mechanisms involved in these effects of EMF are not known. In this study we investigated whether exposure to 60-Hz sinusoidal magnetic fields (0.3-1.2 G for 3-72 h) would cause proliferation of human astrocytoma cells. Sixty-Hertz magnetic fields (MF) caused a time- and dose-dependent increase in proliferation of astrocytoma cells, measured by (3)H-thymidine incorporation and by flow cytometry, and strongly potentiated the effect of two agonists (the muscarinic agonist carbachol and the phorbol ester PMA). However, MF had no effect on DNA synthesis of rat cortical astrocytes, i.e., of similar, nontransformed cells. To determine the amount of heating induced by MF, temperatures were also recorded in the medium. Both 1.2 G MF and a sham exposure caused a 0.7 degrees C temperature increase in the medium; however, (3)H-thymidine incorporation induced by sham exposure was significantly less than that caused by MF. GF 109203X, a rather specific protein kinase C (PKC) inhibitor, and down-regulation of PKC inhibited the effect of MF on basal and on agonist-stimulated (3)H-thymidine incorporation. These data indicate that MF can increase the proliferation of human astrocytoma cells and strongly potentiate the effects of two agonists. These findings may provide a biological basis for the observed epidemiological associations between MF exposure and brain tumors. Copyright 2000 Academic Press.

Risk of DDT residue in maize consumed by infants as complementary diet in southwest Ethiopia.

Science.gov (United States)

Mekonen, Seblework; Lachat, Carl; Ambelu, Argaw; Steurbaut, Walter; Kolsteren, Patrick; Jacxsens, Liesbeth; Wondafrash, Mekitie; Houbraken, Michael; Spanoghe, Pieter

2015-04-01

Infants in Ethiopia are consuming food items such as maize as a complementary diet. However, this may expose infants to toxic contaminants like DDT. Maize samples were collected from the households visited during a consumption survey and from markets in Jimma zone, southwestern Ethiopia. The residues of total DDT and its metabolites were analyzed using the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method combined with dispersive solid phase extraction cleanup (d-SPE). Deterministic and probabilistic methods of analysis were applied to determine the consumer exposure of infants to total DDT. The results from the exposure assessment were compared with the health based guidance value in this case the provisional tolerable daily intake (PTDI). All maize samples (n=127) were contaminated by DDT, with a mean concentration of 1.770 mg/kg, which was far above the maximum residue limit (MRL). The mean and 97.5 percentile (P 97.5) estimated daily intake of total DDT for consumers were respectively 0.011 and 0.309 mg/kg bw/day for deterministic and 0.011 and 0.083 mg/kg bw/day for probabilistic exposure assessment. For total infant population (consumers and non-consumers), the 97.5 percentile estimated daily intake were 0.265 and 0.032 mg/kg bw/day from the deterministic and probabilistic exposure assessments, respectively. Health risk estimation revealed that, the mean and 97.5 percentile for consumers, and 97.5 percentile estimated daily intake of total DDT for total population were above the PTDI. Therefore, in Ethiopia, the use of maize as complementary food for infants may pose a health risk due to DDT residue. Copyright © 2014 Elsevier B.V. All rights reserved.

The sorption behavior of DDT onto sediment in the presence of surfactant cetyltrimethylammonium bromide

International Nuclear Information System (INIS)

Cao Xiaoyan; Han Huayu; Yang Guipeng; Gong Xiaofei; Jing Jianning

2011-01-01

Highlights: → The sorption behavior of a complex system consists of DDT and CTAB onto marine sediment was studied. → Batch experiments were carried out to investigate the kinetics and thermodynamics. → The presence of CTAB could remarkably accelerate and enhance the sorption of DDT. → The sorption of DDT had relatively more negative ΔG 0 and ΔH 0 in the presence of CTAB. - Abstract: The sorption behavior of p,p'- and o,p'-dichlorodiphenyltrichloroethane (DDT) in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) on sediment was studied. Batch experiments were carried out to investigate the kinetics and thermodynamics of the process. The kinetic behavior of these three chemicals on sediment was described by pseudo-second-order kinetic equations, and the isotherms followed the Freundlich model well. The presence of CTAB was able to remarkably accelerate and enhance the sorption of DDT, whereas DDT showed no effect on the sorption of CTAB in our considered concentration ranges. The thermodynamic parameters, such as standard enthalpy change (ΔH 0 ), standard entropy change (ΔS 0 ) and standard Gibbs free energy change (ΔG 0 ) showed that the sorption process of p,p'- and o,p'-DDT was physical, spontaneous and exothermic, and the randomness at the solid-liquid interface increased during the process. In the presence of CTAB, the sorption of DDT showed significantly negative ΔG 0 and ΔH 0 values.

Experiment and Simulation Analysis on Noise Attenuation of Al/MF Cylindrical Shells

Directory of Open Access Journals (Sweden)

Bin Li

2017-01-01

Full Text Available For the issue concerning internal noise reduction of Al-made cylindrical shell structure, the noise control method of laying melamine foam (MF layer is adopted for in-shell noise attenuation experiments of Al and Al/MF cylindrical shells and corresponding internal noise response spectrograms are obtained. Based on the Virtual.Lab acoustics software, a finite element model is established for the analysis of noise in the Al/MF cylinder shell and numerical simulation computation is conducted for the acoustic mode and in-shell acoustic response; the correctness of the finite element model is verified via comparison with measured data. On this basis, influence rules of different MF laying rate and different laying thickness on acoustic cavity resonance response within the low and medium frequency range of 100–400 Hz are studied. It is indicated that noise reduction increases with MF laying rate, but the amplification decreases along with the rising of MF laying rate; noise reduction per unit thickness decreases with the increase of laying thickness, while noise reduction per unit area increases.

Corrosion failure of a bolt made of the 25Kh1MF material

International Nuclear Information System (INIS)

Liska, V.; Cechova, D.; Velkoborsky, J.

1989-01-01

M36x4 bolts, of which there are 222 at each nuclear power plant unit, are made of the 25Kh1MF or 38KhN3MFA steel. They are located in an environment with elevated temperature, with damp air and with boric acid. Corrosion of these bolts is due to the rather poor metallurgical quality of the steel. No inadmissible inhomogeneities of the type of lines of inclusions occur in the bolt material produced by cold rolling but defects of the type of laps were found on the threads. It is suggested that if the cold rolling technology were obviated, corrosion failure of the bolts might not occur. (M.D.). 7 figs., 3 refs

High performance a-IGZO thin-film transistors with mf-PVD SiO2 as an etch-stop-layer

NARCIS (Netherlands)

Nag, M.; Steudel, S.; Bhoolokam, A.; Chasin, A.; Rockele, M.; Myny, K.; Maas, J.; Fritz, T.; Trube, J.; Groeseneken, G.; Heremans, P.

2014-01-01

In this work, we report on high-performance bottom-gate top-contact (BGTC) amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistor (TFT) with SiO2 as an etch-stop-layer (ESL) deposited by medium frequency physical vapor deposition (mf-PVD). The TFTs show field-effect mobility (μFE) of

Effect of water content on the persistence of 14C-DDT in a soil under cerrado

International Nuclear Information System (INIS)

Andrea, M.M. de; Ruegg, E.F.

1985-01-01

The influence of moisture on persistence and degradation of 14 C-DDT in a soil under 'cerrado' is studied under laboratory conditions. The persistence of DDT in the Dark Red Latosol medium texture after one year, in spite of a tendency to be more persistente at 1/3 field capacity and less persistent at higher levels of moisture, is related. (Author) [pt

In-utero exposure to DDT and cognitive development among infants and school-aged children

Science.gov (United States)

Jusko, Todd A.; Klebanoff, Mark A.; Brock, John W.; Longnecker, Matthew P.

2012-01-01

Background Dichlorodiphenyltrichloroethane (DDT) continues to be used for control of infectious diseases in several countries. In-utero exposure to DDT and dichlorodiphenyldichloroethylene (DDE) has been associated with developmental and cognitive impairment among children. We examined this association in an historical cohort in which the level of exposure was greater than in previous studies. Methods The association of in-utero DDT and DDE exposure with infant and child neurodevelopment was examined in approximately 1100 subjects in the Collaborative Perinatal Project, a prospective birth cohort enrolling pregnant women from 12 study centers in the U.S. from 1959 to 1965. Maternal DDT and DDE concentrations were measured in archived serum specimens. Infant mental and motor development was assessed at age 8 months using the Bayley Scales of Infant Development, and child cognitive development was assessed at age 7 years using the Wechsler Intelligence Scale for Children. Results Although levels of both DDT and DDE were relatively high in this population (median DDT concentration, 8.9 µg/L; DDE, 24.5 µg/L), neither was related to Mental or Psychomotor Development scores on the Bayley Scales or to Full-Scale IQ at 7 years of age. Categorical analyses showed no evidence of dose-response for either maternal DDT or DDE, and estimates of the association between continuous measures of exposure and neurodevelopment were indistinguishable from 0. Conclusions Adverse associations were not observed between maternal serum DDT and DDE concentrations and offspring neurodevelopment at 8 months or 7 years of age in this cohort. PMID:22766752

Serum levels of DDT and liver function of malaria control personnel

African Journals Online (AJOL)

1991-03-16

Mar 16, 1991 ... a carcinogen in animal models,7 no such effects have been. Research ... found in people with excessive exposure to DDT, such as pesticide-factory workers.8 However, impaired liver function,9 ... of cement dwellings, which were treated with a different DDT ..... Men with intensive occupational exposure to.

Concentraciones de DDT/DDE y riesgo de hipospadias: un estudio piloto de casos y controles

Directory of Open Access Journals (Sweden)

Flores-Luévano Silvia

2003-01-01

Full Text Available OBJETIVO: Evaluar la asociación entre los niveles séricos maternos de DDT/DDE y el riesgo de hipospadias. MATERIAL Y MÉTODOS: Estudio de casos y controles, efectuado en la Ciudad de México durante el periodo 1997-1999, con 41 casos de hipospadias y 28 controles. La informacion obtenida por cuestionario y las muestras sanguíneas fueron evaluadas mediante modelos multivariados de regresión logística. RESULTADOS: Las concentraciones materna de DDT y DDE no mostraron asociación con el riesgo de hipospadias (RM 1.13; IC 95% 0.24-5.29 y RM 0.48; IC 95% 0.15-1.60, respectivamente. Los predictores encontrados fueron hijos de madres con mayor edad (RM 8.69; IC 95% 1.69-44.9, y la actividad laboral durante el embarazo (RM, 4.68; IC 95% 1.15-18.9. CONCLUSIONES: Dado que se cuenta con escasa información sobre los efectos endocrinos a diferentes concentraciones de DDT/DDE en humanos, la dosis pudiera ser un factor determinante sobre el tipo de efecto.

Ubiquitin-specific protease 2 decreases p53-dependent apoptosis in cutaneous T-cell lymphoma

DEFF Research Database (Denmark)

Wei, Tianling; Biskup, Edyta; Gjerdrum, Lise Mette Rahbek

2016-01-01

expression is 50% lower in CTCL cell lines (MyLa2000, SeAx and Hut-78) than in normal T-cells. USP2 is expressed in neoplastic cells in early, plaque-stage mycosis fungoides (MF) and is downregulated in advanced tumor stages. Upon treatment with psoralen with UVA (PUVA) or a p53 activator, nutlin3a, USP2...

Passive sampling of DDT, DDE and DDD in sediments: accounting for degradation processes with reaction-diffusion modeling.

Science.gov (United States)

Tcaciuc, A Patricia; Borrelli, Raffaella; Zaninetta, Luciano M; Gschwend, Philip M

2018-01-24

Passive sampling is becoming a widely used tool for assessing freely dissolved concentrations of hydrophobic organic contaminants in environmental media. For certain media and target analytes, the time to reach equilibrium exceeds the deployment time, and in such cases, the loss of performance reference compounds (PRCs), loaded in the sampler before deployment, is one of the common ways used to assess the fractional equilibration of target analytes. The key assumption behind the use of PRCs is that their release is solely diffusion driven. But in this work, we show that PRC transformations in the sediment can have a measurable impact on the PRC releases and even allow estimation of that compound's transformation rate in the environment of interest. We found that in both field and lab incubations, the loss of the 13 C 2,4'-DDT PRC from a polyethylene (PE) passive sampler deployed at the sediment-water interface was accelerated compared to the loss of other PRCs ( 13 C-labeled PCBs, 13 C-labeled DDE and DDD). The DDT PRC loss was also accompanied by accumulation in the PE of its degradation product, 13 C 2,4'-DDD. Using a 1D reaction-diffusion model, we deduced the in situ degradation rates of DDT from the measured PRC loss. The in situ degradation rates increased with depth into the sediment bed (0.14 d -1 at 0-10 cm and 1.4 d -1 at 30-40 cm) and although they could not be independently validated, these rates compared favorably with literature values. This work shows that passive sampling users should be cautious when choosing PRCs, as degradation processes can affect some PRC's releases from the passive sampler. More importantly, this work opens up the opportunity for novel applications of passive samplers, particularly with regard to investigating in situ degradation rates, pathways, and products for both legacy and emerging contaminants. However, further work is needed to confirm that the rates deduced from model fitting of PRC loss are a true reflection of DDT

MF-101, an estrogen receptor beta agonist for the treatment of vasomotor symptoms in peri- and postmenopausal women.

Science.gov (United States)

Stovall, Dale W; Pinkerton, Joann V

2009-04-01

During peri- and postmenopausal stages, the majority of women experience moderate-to-severe vasomotor symptoms, such as hot flashes and night sweats, that interfere with sleep and reduce quality of life. Estrogen alone or in combination with a progestagen has been the standard therapy for such vasomotor symptoms; however, this therapeutic regimen is associated with severe side effects, such as breast cancer or cardiovascular events. To provide a better treatment option for menopausal women, Bionovo Inc is developing the estrogen receptor (ER)beta-selective agonist MF-101. Selective ER agonists can stimulate either ERalpha or ERbeta and induce tissue-specific estrogen-like effects, thus providing a safer alternative to conventional hormone therapy. MF-101 is derived from 22 herbs that are traditionally used in Chinese medicine for the treatment of menopausal symptoms. MF-101 did not promote the growth of breast cancer cells or stimulate uterine growth in preclinical studies and, in a phase II trial, was demonstrated to be safe and more effective in reducing the frequency and severity of hot flashes in postmenopausal women compared with placebo. To confirm the safety and efficacy of MF-101, larger phase III trials were planned for 2009. Although MF-101 appears to be a promising therapeutic, the herbal composition of the drug may be a disadvantage, because of the increased risk of causing allergic reactions in the general population. Studies with the MF-101-isolated active compounds liquiritigen and chalcone demonstrated selectivity for ERbeta, with no induction of proliferative events. If these isolates were demonstrated to be as effective and safe in clinical trials as preliminary data suggest regarding MF-101, these compounds could change the way clinicians treat menopause-associated symptoms.

Location of a High-Lysine Gene and the DDT-Resistance Gene on Barley Chromosome 7

DEFF Research Database (Denmark)

Jensen, J.

1979-01-01

mutants, nos 1508.18, and 19. Linkage studies with translocations locate the Lys3 locus in the centromere region ofchromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker locifi (fragile stem), s(short rachilla hairs), and r (smooth awn) show...... that the order of the five loci on chromosome 7 from the long to the short chromosome arm is Y, s,fi, lys3, ddt. The distance from locus I to locus ddt is about 100 centimorgans....

The Farm Process Version 2 (FMP2) for MODFLOW-2005 - Modifications and Upgrades to FMP1

Science.gov (United States)

Schmid, Wolfgang; Hanson, R.T.

2009-01-01

aquifer, (f) automatic routing of returnflow from runoff either to reaches of tributary stream segments adjacent to a farm or to one reach nearest to the farm's lowest elevation, (g) farm-well pumping from cell locations regardless of whether an irrigation requirement from these cells exists or not, and (h) specified non-routed water transfers from an undefined source outside the model domain. All of these limitations are overcome in MF2005-FMP2. The new features include (a) simulation of transpiration uptake from variably saturated, fully saturated, or ponded root zones (for example, for crops like rice or riparian vegetation), (b) definition of on-farm efficiency not only by farm but also by crop, (c) simulation of water use and returnflow from non-irrigated vegetation (for example, rain-fed agriculture or native vegetation), (d) use of crop coefficients and reference evapotranspiration, (e) simulation of the delay between percolation from farms through the unsaturated zone and recharge into the uppermost active aquifer by linking FMP2 to the UZF Package, (f) an option to manually control the routing of returnflow from farm runoff to streams, (g) an option to limit pumping to wells located only in cells where an irrigation requirement exists, and (h) simulation of water transfers to farms from a series of well fields (for example, recovery well field of an aquifer-storage-and-recovery system, ASR). In addition to the output of an economic budget for each farm between irrigation demand and supply ('Farm Demand and Supply Budget' in FMP1), a new output option called 'Farm Budget' was created for FMP2, which allows the user to track all physical flows into and out of a water accounting unit at all times. Such a unit can represent individual farms, farming districts, natural areas, or urban areas. The example model demonstrates the application of MF2005-FMP2 with delayed recharge through an unsaturated zone, rejected infiltration in a riparian area, changes in de

DDT in fishes from four different Amazon sites: exposure assessment for breast feeding infants

Energy Technology Data Exchange (ETDEWEB)

D' Amato, C.; Torres, J.P.; Malm, O. [Lab. de Radioisotopos Eduardo Penna Franca, Inst. de Biofisica, UFRJ, RJ (Brazil); Bastos, W. [Lab. de Biogeoquimica, UNIR, Porto Velho (Brazil); Claudio, L.; Markowitz, S. [International Training Program on Environmental and Occupational Health, Mount Sinai School of Medicine, Queens Coll., NY (United States)

2004-09-15

Concerning DDT in food, based on clinical observations as well as experimental animals, the annual Joint FAO/WHO Meetings on Pesticide Residues held in 2000 estimated a Provisional Tolerable Daily Intake (PTDI) for DDT in 0.01 mg/kg/day. Marien and Laflamme have proposed a Tolerable Daily Intake (TDI) for breast feedings infants of 5 x 10{sup -3} mg/kg/day, and conducted an assessment to evaluate the public health significance of eating {sigma}ODDT contaminated fish, accomplished by establishing a daily intake level of DDT for the population of greatest concern, like breastfeeding infants. Their results indicated that mothers who frequently consume contaminated fish could have breast milk DDT concentrations highly enough to expose their infants to levels above the TDI. The aim of this study was to evaluate the ODDT (o,p'-DDT + p,p'-DDT + o,p'-DDE + p,p'-DDE + o,p'-DDD) levels in commercial fish samples from distinct Brazilian Amazon sites, which are consumed by the riverine populations, and to assess the potential health impacts from eating these fishes, especially for breastfeeding infants.

Weakly coupled S=1/2 quantum Heisenberg antiferromagnetic chains in an effective staggered field

International Nuclear Information System (INIS)

Sato, Masahiro; Oshikawa, Masaki

2002-01-01

We study weakly coupled S=1/2 quantum Heisenberg antiferromagnetic chains in an effective staggered field. Applying mean-field (MF) theory, spin-wave theory and chain MF (CMF) theory, we can see analytically some effects of the staggered field in this higher dimensional spin system. In particular, when the staggered field and the inter-chain inter-action compete with each other, we conjecture from the MF theory that a nontrivial phase is present. The spin wave theory predicts that the behavior of the gaps induced by a staggered field is different between the competitive case and the non-competitive case. When the inter-chain interactions are weak enough, we can improve the MF phase diagram by using CMF theory and the analytical results of field theories. The ordered phase region predicted by the CMF theory is fairly smaller than one of the MF theory. Cu-benzoate, CuCl 2 · 2DMSO (dimethylsulphoxide), BaCu 2 (Si 1-x Ge x ) 2 O 7 , etc., could be described by our model in enough low temperature. (author)

DDT in zebra mussels from Lake Maggiore (N. Italy): level of contamination and endocrine disruptions.

Science.gov (United States)

Binelli, Andrea; Bacchetta, Renato; Mantecca, Paride; Ricciardi, Francesco; Provini, Alfredo; Vailati, Giovanni

2004-08-10

The DDT contamination of Lake Maggiore (Northern Italy) has been monitored since a serious pollution event occurred in 1996. To assess the environmental risk associated with this contamination, bioaccumulation data coupled with histopathological markers were evaluated on zebra mussel populations from two different contaminated sites from April 2001 to April 2002. Biomonitoring results showed high DDT pollution in 2001 because of a flood which transported DDTs still contained in the sediments of a polluted river to the lake. DDT concentrations reached values of 4-5 microg/g lipids, higher than those recorded in other industrialized countries but comparable to levels measured in developing ones. In the ovaries of the most highly polluted mussels, histological analyses showed a delay in oocyte maturation and a high incidence of pathological pictures mainly referable to oocyte degeneration and haemocytic infiltration. Moreover, despite the presence of mature sperms, in 2001 first male gamete release occurred about 2 months later than in females. These results indicated a neuroendocrine interference of DDT on Dreissena polymorpha reproduction and also showed that these invertebrates can be successfully used to evaluate ecological implications due to exposure to endocrine disruptors in freshwater environments.

Tissue distribution of HCH and DDT congeners and human health risk associated with consumption of fish collected from Kabul River, Pakistan.

Science.gov (United States)

Aamir, Muhammad; Khan, Sardar; Nawab, Javed; Qamar, Zahir; Khan, Anwarzeb

2016-03-01

Distribution of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) congeners in tissues of four different fish species and their associated potential health risks to local consumers are presented in this paper. The average ∑(HCHs+DDTs) concentration in Glyptothorax punjabensis (214ngg(-1) wet weight (ww)) (carnivores) was found higher than Tor putitora (155ngg(-1) ww) (herbivores). The distribution of ∑(HCHs+DDTs) in all fish tissues was found in order of liver>muscle>stomach>gills. The profile of congeners (β-HCH/∑HCH from 0.29-0.47) indicated that all selected fish species were contaminated with HCH because of its recent usage in the study area. Furthermore, DDT profile ((DDE+DDD)/∑DDT from 0.61-0.78) showed that fish contamination with DDT originated from past usage and long-time degradation mechanism. The average estimated daily dietary intake of ∑HCHs (15.0ngkg(-1) day(-1)) was higher than ∑DDTs (12.5ngkg(-1) day(-1)) by the local consumers via fish consumption. On the basis of both 50th and 95th percentile exposure levels, the carcinogenic hazard ratios for DDT and its congeners were exceeded one (safe limit) for all fish species, indicating a great potential cancer risk for local consumers with life time consumption of contaminated fish collected from Kabul River. Copyright © 2015 Elsevier Inc. All rights reserved.

DDT - A Brief History and Status

Science.gov (United States)

DDT was the first of the modern synthetic insecticides, developed in the 1940s. It helped control diseases such as typhus and malaria. Enviromental concerns led to its cancellation in the 1970s. It still has limited indoor use in Africa to prevent malaria.

Inadvertent exposure to organochlorine pesticides DDT and derivatives in people from the Canary Islands (Spain)

International Nuclear Information System (INIS)

Zumbado, Manuel; Goethals, Muriel; Alvarez-Leon, Eva E.; Luzardo, Octavio P.; Cabrera, Felix; Serra-Majem, Lluis; Dominguez-Boada, Luis

2005-01-01

In 1998, one of the largest determinations of organochlorine pesticides in a representative sample of a Spanish population (682 serum samples from the Canary Islands) was made in the context of the 'Canary Islands Nutrition Survey' (ENCA). In the Canary Islands, extensive farming areas have been developed in these last decades, with greenhouses dedicated to intensive cultivation using DDT in huge amounts. In Spain, similarly to other European countries, DDT was banned in the late 1970s. The pesticide residues in human serum are indicative of past and present exposure to them. Our objective is to point out the differences of pesticide contamination between islands; and together with this, if a connection could be established with gender, age, or habitat of subjects. Concentration of selected persistent organochlorine pollutants (p,p'-DDT, o,p'-DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD, and o,p'-DDD) was measured with gas chromatography-electron capture detector. Almost all of the samples (99.3%) presented detectable levels of some DDT-derivatives, being p,p'-DDE the most frequently detected organochlorine. The median concentration of total DDT body burden, expressed in ng/g fat, present in the Canary Islands (370 ng/g fat) was similar to that found in other European countries, although it was noteworthy that a fourth of the population showed a total DDT body burden higher than 715 ng/g. Interestingly, statistical significant differences were found in serum levels of organochlorine pesticides between islands, being these levels higher in people from Tenerife and Gran Canaria (415 and 612 ng/g fat, respectively), the islands that present both highest population and highest surface devoted to intensive agriculture. As expected, serum levels of both total DDT body burden and p,p'-DDE increased with age. Statistically significant differences were also found in relation to gender, women showing higher levels of these organochlorine pesticides than men. One of the most relevant

Residues in cottonseed oil and cake resulting from the combined application of DDT and dimethoate

International Nuclear Information System (INIS)

El Zorgani, G.A.; Ahmed, M.M.

1981-01-01

Cotton plants were treated with a combination of DDT and dimethoate under conditions of local agricultural practice to study the fate and magnitude of both chemicals in the cottonseed and related products. GLC and nuclear (using 14 C-DDT) techniques were used. DDT residues in the crude oil averaged 0.115 mg/kg; mainly as p,p'-DDT while residues in the cake were not detected. Dimethoate and dimethoxon in the crude oil were 0.13 and 0.01 mg/kg respectively. The cake contained 0.14 mg/kg dimethoate and 0.01 mg/kg dimethoxon. By simulating commercial oil processing in the laboratory using 14 C-DDT fortified oil samples it was found that alkali treatment and bleaching removed only 7% of the total residue, while deodorization effected removal of 40-50% of the residue. (author)

Absence of 60-Hz, 0.1-mT magnetic field-induced changes in oncogene transcription rates or levels in CEM-CM3 cells.

Science.gov (United States)

Jahreis, G P; Johnson, P G; Zhao, Y L; Hui, S W

1998-12-22

Our objective was to assess the reproducibility of the 60-Hz magnetic field-induced, time-dependent transcription changes of c-fos, c-jun and c-myc oncogenes in CEM-CM3 cells reported by Phillips et al. (Biochim. Biophys. Acta, 1132 (1992) 140-144). Cells were exposed to a 60-Hz magnetic field (MF) at 0.1 mT (rms), generated by a pair of Helmholtz coils energized in a reinforcing (MF) mode, or to a null magnetic field when the coils were energized in a bucking (sham) mode. After MF or sham exposure for 15, 30, 60 or 120 min, nuclei and cytoplasmic RNA were extracted. Transcription rates were measured by a nuclear run-on assay, and values were normalized against either their zero-time exposure values, or against those of the c-G3PDH (housekeeping) gene at the same time points. There was no significant difference, at P=0.05, detected between MF and either sham-exposed or control cells at any time point. Transcript levels of the oncogenes were measured by Northern analysis and normalized as above. No significant difference (P=0.05) in transcript levels between MF and either sham-exposed or control cells was detected.

MF59- and Al(OH3-adjuvanted Staphylococcus aureus (4C-Staph vaccines induce sustained protective humoral and cellular immune responses, with a critical role for effector CD4 T cells at low antibody titers.

Directory of Open Access Journals (Sweden)

Elisabetta eMonaci

2015-09-01

Full Text Available Staphylococcus aureus (S. aureus is an important opportunistic pathogen that may cause invasive life-threatening infections like sepsis and pneumonia. Due to increasing antibiotic-resistance, the development of an effective vaccine against S. aureus is needed. Although a correlate of protection against staphylococcal diseases is not yet established, several findings suggest that both antibodies and CD4 T cells might contribute to optimal immunity. In this study, we show that adjuvanting a multivalent vaccine (4C-Staph with MF59, an oil-in-water emulsion licensed in human vaccines, further potentiated antigen-specific IgG titers and CD4 T cell responses compared to alum and conferred protection in the peritonitis model of S. aureus infection. Moreover, we showed that MF59- and alum-adjuvanted 4C-Staph vaccines induced persistent antigen-specific humoral and T cell responses, and protected mice from infection up to 4 months after immunization. Furthermore, 4C-Staph formulated with MF59 was used to investigate which immune compartment is involved in vaccine-induced protection. Using CD4 T cell-depleted mice or B cell deficient mice, we demonstrated that both T and B cell responses contributed to 4C-Staph vaccine-mediated protective immunity. However, the role of CD4 T cells seemed more evident in the presence of low antibody responses. This study provides preclinical data further supporting the use of the adjuvanted 4C-Staph vaccines against S. aureus diseases, and provides critical insights on the correlates of protective immunity necessary to combat this pathogen.

Dissipation and degradation of /sup 14/C-DDT in Potohar area Islamabad soil under field conditions

International Nuclear Information System (INIS)

Hussain, A.; Asi, M.R.; Iqbal, Z.; Muhammad, A.; Khan, T.A.

2002-01-01

An experiment was conducted in Potohar area, Islamabad for one and half year period to investigate the dissipation and degradation of /sup 14/C-DDT in soil The study revealed that binding of /sup 14/C-DDT to the soil increased gradually with the passage of time. The extractable residues decreased in the same period. Results also indicated that /sup 14/C-DDT dissipated more rapidly in this environment as compared to the temperate regions. The overall half-life of DDT was 260 days. (author)

An Investigation of Reverse Flotation Separation of Sericite from Graphite by Using a Surfactant: MF

Directory of Open Access Journals (Sweden)

Yangshuai Qiu

2016-06-01

Full Text Available In this paper, a surfactant, atlox4862 (formaldehyde condensate of methyl naphthalene sulfonic sodium salt (MF, was introduced as a depressant for reverse flotation separation of sericite from graphite. Natural flake graphite has a strong hydrophobic property. After interacting with MF, the graphite became moderately hydrophilic. The flotation results showed that MF had a depressing ability for both sericite and graphite and that the flotation separation of sericite from graphite was attributed to the different declining levels of recovery between graphite and sericite with increased MF concentration. For a pulp pH of 8 and a MF concentration of 250 mg/L, the recovery rates of sericite and graphite were 89.7% and 11.3%, respectively. The results of the FTIR spectra and zeta potential measurements demonstrated that the interaction of MF with graphite and sericite is mainly through electrostatic attraction. MF was preferred to adsorb on the surface of graphite, decreasing its zeta potential and improving its hydrophilicity more than that of sericite.

Pressure Amplification Off High Impedance Barriers in DDT

Energy Technology Data Exchange (ETDEWEB)

Heatwole, Eric Mann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Broilo, Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kistle, Trevin Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Gary Robert Jr. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-04-23

The Deflagration-to-Detonation Transition (DDT) in one-dimensional porous explosive, where combustion in an explosive transitions to detonation, can be described by the following model. This simplified model proceeds in five steps, as follows: 1) Ignition of the explosive, surface burning. 2) Convective burning, with the flame front penetrating through the porous network of the explosive. This proceeds until the pressure grows high enough to result in choked flow in the pores restricting the convective burn. 3) The choked flow results in the formation of a high-density compact of explosive. This compact is driven into undisturbed material by the pressure of the burning explosive. See Figure1. 4) The compression of the undisturbed porous explosive by the compact leads to the ignition of a compressive burn. This builds in pressure until a supported shock forms. 5) The shock builds in pressure until detonation occurs. See Figure 2 for an overview streak of the proceeding steps.

Engineering and Environmental Study of DDT Contamination of Huntsville Spring Branch, Indian Creek, and Adjacent Lands and Waters, Wheeler Reservoir, Alabama. Volume 2. Appendices I-III.

Science.gov (United States)

1980-11-01

with increased DOT concentration and tem- perature but decreases substantially when the soil water content de- creases below one molecular layer of...200 ppm DDT in four water-logged, urease amended soils varying in organic matter and free iron contents at 35°C for 3 to 28 days. The rates of DDT...degradation were related to the rates of form- ation of ferrous iron in urease amended soils and DDT degradation was more rapid in soils with lower redox

Study of compoisiton of saturated vapor of MF-CuF2 systems, where M=K, Rb, Cs

International Nuclear Information System (INIS)

Morozov, I.V.; Korenev, Yu.M.

1993-01-01

Investigation into composition of saturated vapor of MF-CuF 2 systems where M=K, Rb, Cs is conducted using high-temperature mass-spectrometry. Existence of MCuF 3 molecules in gas phase is determined. MCuF 3(r) dissociation enthalpies are calculated using the first law-of thermodynamics and are compared with theoretically determined values. Value Δ D G 0 944 (CsCuF 3(r) =105.6±6.3 kj/mol is determined

Sobre el Uso del DDT

Directory of Open Access Journals (Sweden)

Garcés Carlos

1949-06-01

Full Text Available Con el advenimiento del DDT como elemento de lucha contra las numerosas pestes que atacan a las plantas y a los animales y definitivamente probada su gran efectividad para ello, su uso se ha hecho extensivo en todas partes y en todas las ocasiones posibles, y así este insecticida ha venido desplazando a los que hasta la fecha se estaban empleando

First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area.

Science.gov (United States)

Bouwman, Hindrik; Bornman, Riana; van Dyk, Cobus; Barnhoorn, Irene

2015-10-01

In malaria-endemic areas, where DDT is still used for vector control by indoor residual spraying (IRS), the concentrations of DDT in human blood and breast milk are high, and there are indications of human health impacts. To identify the possible avenues of exposure reduction, we created the concept of a Total Homestead Environment Approach (THEA). THEA characterizes the interactions between DDT, humans, and the biota within and around homesteads. One dietary route of human exposure and uptake of DDT, namely, chicken egg consumption, has to our knowledge never been studied. The ΣDDT in eggs from a DDT-sprayed village ranged between 5200 and 48,000 ng/g wm (wet mass), with a median of 11,000 ng/g wm. On a lipid mass-basis (lm), the mean ΣDDT for eggs from the sprayed village was 100,000 ng/g lm. The maximum egg concentration observed was three orders of magnitude higher than the median. The acceptable daily intake (ADI) was not exceeded based on the consumption of three eggs per week for a 60 kg person. This equates to an intake of 0.089 g DDT per person per year. Chicken egg consumption is therefore a possible target for exposure reduction, probably best achieved by reducing the DDT concentrations in soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of melting technique on grain size and heat resistance of the 12Kh1MF steel

International Nuclear Information System (INIS)

Lanskaya, K.A.; Kulikova, L.V.; Butneva, N.I.

1978-01-01

Investigated are the 12Kh1MF steel melted in open-hearth and arc furnaces (deoxidation by aluminium in 1.0 kg/t quantity) and then subjected to electroslag melting. The size of an austenitic grain depends on the residual contents of nitrogen and aluminium in steel. The open-hearth metal subjected to electroslag melting and containing a small quantity of nitrogen (0.006%) and aluminium (0.013%) has coarse austenitic grains and higher heat resistance compared to the steel melted in an arc furnace and also sub ected to electroslag melting. The nitride analysis of steel is carried out

Prenatal Exposure to DDT and Pyrethroids for Malaria Control and Child Neurodevelopment: The VHEMBE Cohort, South Africa.

Science.gov (United States)

Eskenazi, Brenda; An, Sookee; Rauch, Stephen A; Coker, Eric S; Maphula, Angelina; Obida, Muvhulawa; Crause, Madelein; Kogut, Katherine R; Bornman, Riana; Chevrier, Jonathan

2018-04-06

Although indoor residual spraying (IRS) with dichlorodiphenyltrichloroethane (DDT) and pyrethroids effectively controls malaria, it potentially increases human exposure to these insecticides. Previous studies suggest that prenatal exposure to these insecticides may impact human neurodevelopment. We aimed to estimate the effects of maternal insecticide exposure and neurodevelopment of toddlers living in a malaria-endemic region currently using IRS. The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort of 752 mother-child pairs in Limpopo, South Africa. We measured maternal exposure to DDT and its breakdown product, dichlorodiphenyldichloroethylene (DDE), in maternal serum, and measured pyrethroid metabolites in maternal urine. We assessed children's neurodevelopment at 1 and 2 y of age using the Bayley Scales of Infant Development, third edition (BSID-III), and examined associations with maternal exposure. DDT and DDE were not associated with significantly lower scores for any BSID-III scale. In contrast, each 10-fold increase in cis -DCCA, trans -DCCA, and 3-phenoxybenzoic acid were associated, respectively, with a -0.63 (95% CI: -1.14, -0.12), -0.48 (95% CI: -0.92, -0.05), and -0.58 (-1.11, -0.06) decrement in Social-Emotional scores at 1 y of age. In addition, each 10-fold increase in maternal cis -DBCA levels was associated with significant decrements at 2 y of age in Language Composite scores and Expressive Communication scores [β=-1.74 (95% CI: -3.34, -0.13) and β=-0.40 (95% CI: -0.77, -0.04), respectively, for a 10-fold increase]. Significant differences by sex were estimated for pyrethroid metabolites and motor function scores at 2 y of age, with higher scores for boys and lower scores for girls. Prenatal exposure to pyrethroids may be associated at 1 y of age with poorer social-emotional development. At 2 y of age, poorer language development was observed with higher prenatal pyrethroid levels. Considering the

Similarities and differences between helminth parasites and cancer cell lines in shaping human monocytes: Insights into parallel mechanisms of immune evasion.

Directory of Open Access Journals (Sweden)

Prakash Babu Narasimhan

2018-04-01

Full Text Available A number of features at the host-parasite interface are reminiscent of those that are also observed at the host-tumor interface. Both cancer cells and parasites establish a tissue microenvironment that allows for immune evasion and may reflect functional alterations of various innate cells. Here, we investigated how the phenotype and function of human monocytes is altered by exposure to cancer cell lines and if these functional and phenotypic alterations parallel those induced by exposure to helminth parasites. Thus, human monocytes were exposed to three different cancer cell lines (breast, ovarian, or glioblastoma or to live microfilariae (mf of Brugia malayi-a causative agent of lymphatic filariasis. After 2 days of co-culture, monocytes exposed to cancer cell lines showed markedly upregulated expression of M1-associated (TNF-α, IL-1β, M2-associated (CCL13, CD206, Mreg-associated (IL-10, TGF-β, and angiogenesis associated (MMP9, VEGF genes. Similar to cancer cell lines, but less dramatically, mf altered the mRNA expression of IL-1β, CCL13, TGM2 and MMP9. When surface expression of the inhibitory ligands PDL1 and PDL2 was assessed, monocytes exposed to both cancer cell lines and to live mf significantly upregulated PDL1 and PDL2 expression. In contrast to exposure to mf, exposure to cancer cell lines increased the phagocytic ability of monocytes and reduced their ability to induce T cell proliferation and to expand Granzyme A+ CD8+ T cells. Our data suggest that despite the fact that helminth parasites and cancer cell lines are extraordinarily disparate, they share the ability to alter the phenotype of human monocytes.

Similarities and differences between helminth parasites and cancer cell lines in shaping human monocytes: Insights into parallel mechanisms of immune evasion.

Science.gov (United States)

Narasimhan, Prakash Babu; Akabas, Leor; Tariq, Sameha; Huda, Naureen; Bennuru, Sasisekhar; Sabzevari, Helen; Hofmeister, Robert; Nutman, Thomas B; Tolouei Semnani, Roshanak

2018-04-01

A number of features at the host-parasite interface are reminiscent of those that are also observed at the host-tumor interface. Both cancer cells and parasites establish a tissue microenvironment that allows for immune evasion and may reflect functional alterations of various innate cells. Here, we investigated how the phenotype and function of human monocytes is altered by exposure to cancer cell lines and if these functional and phenotypic alterations parallel those induced by exposure to helminth parasites. Thus, human monocytes were exposed to three different cancer cell lines (breast, ovarian, or glioblastoma) or to live microfilariae (mf) of Brugia malayi-a causative agent of lymphatic filariasis. After 2 days of co-culture, monocytes exposed to cancer cell lines showed markedly upregulated expression of M1-associated (TNF-α, IL-1β), M2-associated (CCL13, CD206), Mreg-associated (IL-10, TGF-β), and angiogenesis associated (MMP9, VEGF) genes. Similar to cancer cell lines, but less dramatically, mf altered the mRNA expression of IL-1β, CCL13, TGM2 and MMP9. When surface expression of the inhibitory ligands PDL1 and PDL2 was assessed, monocytes exposed to both cancer cell lines and to live mf significantly upregulated PDL1 and PDL2 expression. In contrast to exposure to mf, exposure to cancer cell lines increased the phagocytic ability of monocytes and reduced their ability to induce T cell proliferation and to expand Granzyme A+ CD8+ T cells. Our data suggest that despite the fact that helminth parasites and cancer cell lines are extraordinarily disparate, they share the ability to alter the phenotype of human monocytes.

Engineering bone regeneration with novel cell-laden hydrogel microfiber-injectable calcium phosphate scaffold

Energy Technology Data Exchange (ETDEWEB)

Song, Yang [Department of Prosthodontics, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong (China); Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Zhang, Chi [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041 (China); Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Wang, Ping, E-mail: dentistping@gmail.com [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Wang, Lin [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); VIP Integrated Department, School and Hospital of Stomatology, Jilin University, Changchun, Jilin 130011 (China); Bao, Chunyun [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041 (China); Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Weir, Michael D.; Reynolds, Mark A. [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Ren, Ke [Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, University of Maryland, Baltimore, MD 21201 (United States); Zhao, Liang, E-mail: lzhaonf@126.com [Department of Endodontics, Periodontics and Prosthodontics, University of Maryland School of Dentistry, Baltimore, MD 21201 (United States); Department of Orthopaedic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515 (China); and others

2017-06-01

Cell-based tissue engineering is promising to create living functional tissues for bone regeneration. The implanted cells should be evenly distributed in the scaffold, be fast-released to the defect and maintain high viability in order to actively participate in the regenerative process. Herein, we report an injectable calcium phosphate cement (CPC) scaffold containing cell-encapsulating hydrogel microfibers with desirable degradability that could deliver cells in a timely manner and maintain cell viability. Microfibers were synthesized using partially-oxidized alginate with various concentrations (0–0.8%) of fibrinogen to optimize the degradation rate of the alginate-fibrin microfibers (Alg-Fb MF). A fibrin concentration of 0.4% in Alg-Fb MF resulted in the greatest enhancement of cell migration, release and proliferation. Interestingly, a significant amount of cell–cell contact along the long-axis of the microfibers was established in Alg-0.4%Fb MF as early as day 2. The injectable tissue engineered construct for bone reconstruct was fabricated by mixing the fast-degradable Alg-0.4%Fb MF with CPC paste at 1:1 volume ratio. In vitro study showed that cells re-collected from the construct maintained good viability and osteogenic potentials. In vivo study demonstrated that the hBMSC-encapsulated CPC-MF tissue engineered construct displayed a robust capacity for bone regeneration. At 12 weeks after implantation, osseous bridge in the rat mandibular defect was observed in CPC-MF-hBMSCs group with a new bone area fraction of (42.1 ± 7.8) % in the defects, which was > 3-fold that of the control group. The novel tissue-engineered construct presents an excellent prospect for a wide range of dental, craniofacial and orthopedic applications. - Highlights: • Microfibers protected cells during CPC mixing and injection, and supported the viability, migration and differentiation of encapsulated cells. • Cells re-collected from the construct maintained good viability

Engineering bone regeneration with novel cell-laden hydrogel microfiber-injectable calcium phosphate scaffold

International Nuclear Information System (INIS)

Song, Yang; Zhang, Chi; Wang, Ping; Wang, Lin; Bao, Chunyun; Weir, Michael D.; Reynolds, Mark A.; Ren, Ke; Zhao, Liang

2017-01-01

Cell-based tissue engineering is promising to create living functional tissues for bone regeneration. The implanted cells should be evenly distributed in the scaffold, be fast-released to the defect and maintain high viability in order to actively participate in the regenerative process. Herein, we report an injectable calcium phosphate cement (CPC) scaffold containing cell-encapsulating hydrogel microfibers with desirable degradability that could deliver cells in a timely manner and maintain cell viability. Microfibers were synthesized using partially-oxidized alginate with various concentrations (0–0.8%) of fibrinogen to optimize the degradation rate of the alginate-fibrin microfibers (Alg-Fb MF). A fibrin concentration of 0.4% in Alg-Fb MF resulted in the greatest enhancement of cell migration, release and proliferation. Interestingly, a significant amount of cell–cell contact along the long-axis of the microfibers was established in Alg-0.4%Fb MF as early as day 2. The injectable tissue engineered construct for bone reconstruct was fabricated by mixing the fast-degradable Alg-0.4%Fb MF with CPC paste at 1:1 volume ratio. In vitro study showed that cells re-collected from the construct maintained good viability and osteogenic potentials. In vivo study demonstrated that the hBMSC-encapsulated CPC-MF tissue engineered construct displayed a robust capacity for bone regeneration. At 12 weeks after implantation, osseous bridge in the rat mandibular defect was observed in CPC-MF-hBMSCs group with a new bone area fraction of (42.1 ± 7.8) % in the defects, which was > 3-fold that of the control group. The novel tissue-engineered construct presents an excellent prospect for a wide range of dental, craniofacial and orthopedic applications. - Highlights: • Microfibers protected cells during CPC mixing and injection, and supported the viability, migration and differentiation of encapsulated cells. • Cells re-collected from the construct maintained good viability

Splice form variant and amino acid changes in MDR49 confers DDT resistance in transgenic Drosophila.

Science.gov (United States)

Seong, Keon Mook; Sun, Weilin; Clark, John M; Pittendrigh, Barry R

2016-03-22

The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R.

Efectos a la salud y exposición a p,p'-DDT y p,p'-DDE: el caso de México Human health effects and p,p'-DDE and p,p'-DDT exposure: the case of Mexico

Directory of Open Access Journals (Sweden)

Luisa Torres-Sánchez

2007-03-01

Full Text Available Basado en la revisión sistemática de 32 artículos publicados en PubMed-Medline hasta enero del 2006 y utilizando como palabras clave DDT exposure, human, milk y Mexico; este estudio analiza la situación acerca de la exposición en México a difenildicloroetano (DDT y su principal metabolito p,p,'-DDE, así como, su posible repercusión sobre la salud humana. Aún cuando, el uso del DDT se suspendió en 1999, los estudios evaluados reportan niveles importantes de p,p'-DDE, en muestras biológicas de suero, tejido adiposo y leche materna de poblaciones no ocupacionalmente expuestas. Así mismo, existen evidencias sobre daños a la salud, especialmente relacionados con el área reproductiva masculina, la lactancia materna y más recientemente daños a nivel celular, así como, alteración en el desarrollo psicomotor de niños expuestos in utero. Aún cuando existen muchas lagunas, acerca de otros efectos adversos a la salud relacionados con la exposición a DDT o sus metabolitos, la experiencia lograda hasta ahora, debe ser tomada en cuenta en México y el resto de Latinoamérica, para que considerando el principio precautorio se legisle sobre el DDT y otros contaminantes orgánicos persistente que tienen actividad y características similares al DDT o sus metabolitos.Based on the systematic revision of 32 articles published in PubMed-Medline until January of 2006 and using like key words DDT exposure, human, milk and Mexico; this study analyzes the situation about the exposure of difenildicloroetano (DDT and its main metabolite p,p,'-DDE in Mexico, as well as, their possible repercussion on the human health. Even though, the use of the DDT in Mexico was banned in 1999, the evaluated studies report significant levels of p, p'-DDE, in biological samples of serum, adipose tissue and maternal milk of populations not occupationally exposed. Also, there are evidences on damages to the health, specially related to the reproductive area, and more

Assessing the underlying breast cancer risk of Chinese females contributed by dietary intake of residual DDT from agricultural soils.

Science.gov (United States)

Tang, Mengling; Zhao, Meirong; Zhou, Shanshan; Chen, Kun; Zhang, Chunlong; Liu, Weiping

2014-12-01

The greatest concern over DDT exposure in China arose since the early 1990s for the rising breast cancer incidence, and the cause still remains to be elucidated. An extensive survey of DDT background in agricultural soils, covered the entire region of China, was conducted. DDT at concentrations greater than 100 ng/g (the China's Farmland Environmental Quality Evaluation Standards for Edible Agricultural Products) was found to impact 42.3 million Chinese population. Considering the geographical differences with diverse DDT contributions and different diet products and habits, the average daily dietary intake was modeled and estimated to be 0.34 μg/kg p,p'-DDE (the main bioactive constituent in DDT). Population attributable fraction derived from a case-control study from 78 women with breast cancer and 72 controls was used to assess the DDT exposure risk to breast cancer. Based on the estimated population attributable fraction with a median value of 0.6% (IQR 0.23-2.11%), the excess annual breast cancer incidence rate attributable to p,p'-DDE exposure averaged 0.06×10(-5) with significant spatial variations varying from 0.00021×10(-5) to 11.05×10(-5) in Chinese females. Exposure to DDT is a contributor to breast cancer, but the overall limited relative risk and population attributable fraction imply confounding factors for breast cancer in Chinese females. Exposure risk in a regional scale helps understand the cause and prevention of breast cancer. Our mapping and modeling method could be used to assess other environmental carcinogens and related cancer diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Intranasal Immunization Using Mannatide as a Novel Adjuvant for an Inactivated Influenza Vaccine and Its Adjuvant Effect Compared with MF59.

Directory of Open Access Journals (Sweden)

Shu-Ting Ren

Full Text Available Intranasal vaccination is more potent than parenteral injection for the prevention of influenza. However, because the poor efficiency of antigen uptake across the nasal mucosa is a key issue, immunostimulatory adjuvants are essential for intranasal vaccines. The immunomodulator mannatide or polyactin (PA has been used for the clinical treatment of impaired immunity in China, but its adjuvant effect on an inactivated trivalent influenza vaccine (ITIV via intranasal vaccination is unclear. To explore the adjuvant effect of PA, an inactivated trivalent influenza virus with or without PA or MF59 was instilled intranasally once a week in BALB/c mice. Humoral immunity was assessed by both the ELISA and hemagglutination inhibition (HI methods using antigen-specific antibodies. Splenic lymphocyte proliferation and the IFN-γ level were measured to evaluate cell-mediated immunity. The post-vaccination serum HI antibody geometric mean titers (GMTs for the H1N1 and H3N2 strains, antigen-specific serum IgG and IgA GMTs, mucosal SIgA GMT, splenic lymphocyte proliferation, and IFN-γ were significantly increased in the high-dose PA-adjuvanted vaccine group. The seroconversion rate and the mucosal response for the H3N2 strain were significantly elevated after high-dose PA administration. These adjuvant effects of high-dose PA for the influenza vaccine were comparable with those of the MF59 adjuvant, and abnormal signs or pathological changes were not found in the evaluated organs. In conclusion, PA is a novel mucosal adjuvant for intranasal vaccination with the ITIV that has safe and effective mucosal adjuvanticity in mice and successfully induces both serum and mucosal antibody responses and a cell-mediated response.

Exposure to DDT and its metabolites from khat (Catha edulis) chewing: Consumers risk assessment from southwestern Ethiopia.

Science.gov (United States)

Mekonen, Seblework; Ambelu, Argaw; Negassa, Belay; Spanoghe, Pieter

2017-07-01

Khat (Catha edulis) is one of the most consumed plant in the horn of African countries. However, it is a stimulant plant that has several side effects on the health of consumers. On top of that, the khat leaves used for human consumption are often contain contaminants such as pesticide residues. The present study aims to investigate the level of DDT residue and its metabolites (p'p-DDE, p'p-DDD, o'p-DDT and p'p-DDT) in khat samples and to undertake exposure assessment to consumers. The khat samples were collected from local markets in southwestern Ethiopia. Consumption survey was undertaken using 24 h recall method for both male and female khat consumers. The finding showed that 80% of the khat samples contained DDT and its metabolites. Some of the residues were above the maximum residue limit (MRL) set by Food and Agricultural Organization (FAO). The concentration of p'p-DDE and p'p-DDT in khat were in the range of 0.033-0.113 and 0.010-0.026 mg/kg, respectively. High concentration of the metabolite (p'p-DDE) compared to the parent compound (p'p-DDT) revealed the historical use of DDT in the study area. Probabilistic exposure analysis indicated that the mean and 97.5 percentile (P97.5), of the estimated daily intake of total DDT were 0.002 and 0.006 mg/kg bw/day, respectively. The study concluded that khat consumers are exposed to the stimulant effect of the plant as well as DDT and its metabolites in Jimma zone. Copyright © 2017 Elsevier Inc. All rights reserved.

Perinatal exposure of mice to the pesticide DDT impairs energy expenditure and metabolism in adult female offspring.

Directory of Open Access Journals (Sweden)

Michele La Merrill

Full Text Available Dichlorodiphenyltrichloroethane (DDT has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring.

Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring

Science.gov (United States)

La Merrill, Michele; Karey, Emma; Moshier, Erin; Lindtner, Claudia; La Frano, Michael R.; Newman, John W.; Buettner, Christoph

2014-01-01

Dichlorodiphenyltrichloroethane (DDT) has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring. PMID:25076055

Developing trading strategies based on fractal finance: An application of MF-DFA in the context of Islamic equities

Science.gov (United States)

Dewandaru, Ginanjar; Masih, Rumi; Bacha, Obiyathulla Ismath; Masih, A. Mansur. M.

2015-11-01

We provide a new contribution to trading strategies by using multi-fractal de-trended fluctuation analysis (MF-DFA), imported from econophysics, to complement various momentum strategies. The method provides a single measure that can capture both persistency and anti-persistency in stock prices, accounting for multifractality. This study uses a sample of Islamic stocks listed in the U.S. Dow Jones Islamic market for a sample period covering 16 years starting in 1996. The findings show that the MF-DFA strategy produces monthly excess returns of 6.12%, outperforming other various momentum strategies. Even though the risk of the MF-DFA strategy may be relatively higher, it can still produce a Sharpe ratio of 0.164, which is substantially higher than that of the other strategies. When we control for the MF-DFA factor with the other factors, its pure factor return is still able to yield a monthly excess return of 1.35%. Finally, we combine the momentum and MF-DFA strategies, with the proportions of 90/10, 80/20, and 70/30 and by doing so we demonstrate that the MF-DFA measure can boost the total monthly excess returns as well as Sharpe ratio. The value added is non-linear which implies that the additional returns are associated with lower incremental risk.

Modeling the fate of p,p'-DDT in water and sediment of two typical estuarine bays in South China: Importance of fishing vessels' inputs.

Science.gov (United States)

Fang, Shu-Ming; Zhang, Xianming; Bao, Lian-Jun; Zeng, Eddy Y

2016-05-01

Antifouling paint applied to fishing vessels is the primary source of dichloro-diphenyl-trichloroethane (DDT) to the coastal marine environments of China. With the aim to provide science-based support of potential regulations on DDT use in antifouling paint, we utilized a fugacity-based model to evaluate the fate and impact of p,p'-DDT, the dominant component of DDT mixture, in Daya Bay and Hailing Bay, two typical estuarine bays in South China. The emissions of p,p'-DDT from fishing vessels to the aquatic environments of Hailing Bay and Daya Bay were estimated as 9.3 and 7.7 kg yr(-1), respectively. Uncertainty analysis indicated that the temporal variability of p,p'-DDT was well described by the model if fishing vessels were considered as the only direct source, i.e., fishing vessels should be the dominant source of p,p'-DDT in coastal bay areas of China. Estimated hazard quotients indicated that sediment in Hailing Bay posed high risk to the aquatic system, and it would take at least 21 years to reduce the hazards to a safe level. Moreover, p,p'-DDT tends to migrate from water to sediment in the entire Hailing Bay and Daya Bay. On the other hand, our previous research indicated that p,p'-DDT was more likely to migrate from sediment to water in the maricultured zones located in shallow waters of these two bays, where fishing vessels frequently remain. These findings suggest that relocating mariculture zones to deeper waters would reduce the likelihood of farmed fish contamination by p,p'-DDT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective enrichment and biochemical characterization of seven human skin fibroblasts cell types in vitro

International Nuclear Information System (INIS)

Rodemann, H.P.; Bayreuther, K.; Francz, P.I.; Dittmann, K.; Albiez, M.

1989-01-01

The mitotic and postmitotic populations of the human skin fibroblast cell line HH-8 are heterogeneous when studied in vitro. There are reproducible changes in the frequencies of the mitotic fibroblasts (MF), MF I, MF II, MF III, and the postmitotic fibroblasts (PMF), PMF IV, PMF V, PMF VI, and PMF VII. For biochemical characterization, methods for selective enrichment of homogeneous populations of these seven fibroblast cell types have been established. Clonal populations with 95% purity for the mitotic fibroblasts MF I, MF II, and MF III can be raised in uniform clone types of fibroblasts (CTF) CTF I, CTF II, and CTF III. Pure clonal subpopulations of MF I type cells are present in mass populations in the range of 1-20 cumulative population doublings (CPD). Populations of mitotic fibroblasts represent nearly homogeneous populations of MF II (75-85% purity) in the range of 28-34 CPD and MF III (73-86% purity) in the range of 48-53 CPD. These populations can be easily expanded to up to 10(7)-10(8) cells. The spontaneous transition of MF III to PMF VI takes 140-180 days. In order to shorten this period and increase the proportion of distinct postmitotic types, mitotic fibroblast mass populations (CPD 30-32, MF II: 75-85% purity) have been induced by uv-irradiation to differentiate to nearly homogeneous populations of PMF IV, PMF V, PMF VI, and PMF VII within 4 to 36 days of culture. Using this method, 10(7) cells of one differentiation stage can be obtained. Spontaneously arising and experimentally selected or induced homogeneous clonal and mass populations of MF I, MF II, MF III, PMF IV, PMF V, PMF VI, and PMF VII express an identical differentiation-dependent and cell-type-specific [35S]methionine-labeled polypeptide pattern

Behaviors of 14C-butachlor, 14C-chlorpyrifos and 14C-DDT in Rana japonica japonica Guenther

International Nuclear Information System (INIS)

Zhang Yiqiang; Zhong Chuangguang; Zhao Xiaokui; Chen Shunhua

2002-01-01

The research on the behaviors of 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT in the frog Rana japonica japonica Guenther was carried out. After administrated per os to the frogs in doses of 380, 347, 363 Bq/g, 14 C-butachlor, 14 C-chlorpyrifos and 14 C-DDT, were distributed respectively to various organs within 24 h with specific accumulating organs as gallbladder, intestine and intestine, relevantly to the pesticides described. Compared to that in gallbladder and intestine, the radioactivity of many organs was extremely low, and this might due to the characters of the pesticides. Analysis of the metabolites of 14 C-DDT in frog at 24 th hr demonstrated that DDT was difficult to be degraded. Most 14 C-butachlor, 14 C-chlorpyrifos 14 C-DDT in liver and fat or ovary of frog was extractable with acetone. However, there were some differences between the pesticides, and the organs as well. And 14 C-butachlor, 14 C-chlorpyrifos or 14 C-DDT were better bound in liver than in fat

Health and ecological risk-based characterization of soil and sediment contamination in shipyard with long-term use of DDT-containing antifouling paint

Energy Technology Data Exchange (ETDEWEB)

Guo, Guanlin; Zhang, Chao [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wu, Guanglong; Ding, Qiong [Foreign Economic Cooperation Office, Ministry of Environmental Protection of China, Beijing, 100035 (China); Wang, Shijie [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Fasheng, E-mail: Lifs@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

2013-04-15

Dichlorodiphenyltrichloroethane (DDT) was a frequently occurring type of persistent organic environmental pollutant in China and DDT-containing antifouling paint could be the main contributor of DDT to shipyards and fishing harbors. A field survey was conducted in a shipyard in southern China to investigate the content and distribution of DDT in soil and sediments. Human health and screening-level ecological risk assessments were conducted for DDT contamination in soil and sediments and the results indicated that total DDT in all samples tested exceeded present advisory safe limits. Analysis of the composition and distribution implicated DDT-containing antifouling paint used for ship maintenance as an important source of DDT. Individual and cumulative health risks for residents exceeded the extra lifetime cancer risks of 10{sup −6} and 10{sup −5}, mainly from exposure to soil, ingestion and dermal contact. DDT in sediments is associated with a high level of toxicity for the benthic community when > 99% of samples exceed the threshold concentration likely to be responsible for effects and severe effects. Further risk control for DDT is required to ensure safety for human health, the benthic community and the environment. - Highlights: ► DDT ranked high concentration both in sediments and soil in a shipyard. ► Composition analysis indicated DDT antifouling paint was the main source. ► High loading DDT in sediments resulted in high probability of ecological risks. ► Potential health risks for residents were mainly from the exposure of ingestion.

Health and ecological risk-based characterization of soil and sediment contamination in shipyard with long-term use of DDT-containing antifouling paint

International Nuclear Information System (INIS)

Guo, Guanlin; Zhang, Chao; Wu, Guanglong; Ding, Qiong; Wang, Shijie; Li, Fasheng

2013-01-01

Dichlorodiphenyltrichloroethane (DDT) was a frequently occurring type of persistent organic environmental pollutant in China and DDT-containing antifouling paint could be the main contributor of DDT to shipyards and fishing harbors. A field survey was conducted in a shipyard in southern China to investigate the content and distribution of DDT in soil and sediments. Human health and screening-level ecological risk assessments were conducted for DDT contamination in soil and sediments and the results indicated that total DDT in all samples tested exceeded present advisory safe limits. Analysis of the composition and distribution implicated DDT-containing antifouling paint used for ship maintenance as an important source of DDT. Individual and cumulative health risks for residents exceeded the extra lifetime cancer risks of 10 −6 and 10 −5 , mainly from exposure to soil, ingestion and dermal contact. DDT in sediments is associated with a high level of toxicity for the benthic community when > 99% of samples exceed the threshold concentration likely to be responsible for effects and severe effects. Further risk control for DDT is required to ensure safety for human health, the benthic community and the environment. - Highlights: ► DDT ranked high concentration both in sediments and soil in a shipyard. ► Composition analysis indicated DDT antifouling paint was the main source. ► High loading DDT in sediments resulted in high probability of ecological risks. ► Potential health risks for residents were mainly from the exposure of ingestion

(DDT) and hexachlorohexane (HCH) pesticide residues in foodstuffs ...

African Journals Online (AJOL)

Dichloro-diphenyl-trichloro-ethane (DDT) and hexachlorohexane (HCH) pesticide residues in foodstuffs from markets in Ile-Ife, Nigeria. ... International Journal of Biological and Chemical Sciences ... Keywords: Dichlorodiphenyltrichloroethane, hexachlorocyclohexane, pesticide, residue, cowpea grain, yam chip.

Spatial distributions and enantiomeric signatures of DDT and its metabolites in tree bark from agricultural regions across China.

Science.gov (United States)

Niu, Lili; Xu, Chao; Zhang, Chunlong; Zhou, Yuting; Zhu, Siyu; Liu, Weiping

2017-10-01

Tree bark is considered as an effective passive sampler for estimating the atmospheric status of pollutants. In this study, we conducted a national scale tree bark sampling campaign across China. Concentration profiles revealed that Eastern China, especially the Jing-Jin-Ji region (including Hebei Province, Beijing and Tianjin) was a hot spot of bark DDT pollution. The enantioselective accumulation of o,p'-DDT was observed in most of the samples and 68% of them showed a preferential depletion of (+)-o,p'-DDT. These results suggest that DDTs in rural bark are likely from combined sources including historical technical DDTs and fresh dicofol usage. The tree bulk DDT levels were found to correlate with soil DDT concentrations, socioeconomy and PM 2.5 of the sampling sites. It thus becomes evident that the reemission from soils and subsequent atmospheric deposition were the major pathways leading to the accumulation of DDTs in bark. Based on a previously established bark-air partitioning model, the concentrations of DDTs in the air were estimated from measured concentrations in tree bark, and the results were comparable to those obtained by the use of passive sampling with polyurethane foam (PUF) disks. Our results demonstrate the feasibility of delineating the spatial variations in atmospheric concentration and tracing sources of DDTs by integrating the use of tree bark with enantiomeric analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene (DDE) Transformation Rates on the Palos Verdes Shelf, CA

Science.gov (United States)

Eganhouse, Robert P.; Pontolillo, James

2008-01-01

In 1953, the world's largest producer of DDT, Montrose Chemical Corporation, began to discharge process wastes into sewers of the Los Angeles County Sanitation Districts (LACSD), California. By 1971, when the sewer connection was terminated, approximately 1,500-2,000 metric tons of DDT had been introduced to the LACSD treatment plant in Carson, CA. After treatment, effluent from this plant was released to the ocean through a submarine outfall system on the Palos Verdes Shelf (PVS) near Los Angeles, resulting in the accumulation of highly contaminated marine sediments. Numerous investigations of the PVS have been undertaken since the late 1960s, but few have focused on the biogeochemical fate of DDT and its transformation products. In the early 1990s, it was shown that DDE, the major DDT compound in the sediments, was being reductively dechlorinated by microorganisms resident in sediments on the PVS. The U.S. Geological Survey undertook a study in cooperation with the U.S. Environmental Protection Agency to provide a better understanding of the range of reductive dechlorination rates on the PVS and the environmental factors that control them. Existing data show that rates of reductive dechlorination are variable spatially. A comparison of data from two cores collected approximately 7 kilometers downcurrent from the outfall systems in 1992 and 2003 yielded an average first-order transformation rate of approximately 0.05 yr-1. A multistep reaction model suggests that inventories of DDE in PVS sediments at the study site will continue to decline, whereas the inventory of the metabolite DDNU will reach a maximum around 2014.

Validation of a multi-frequency electrical impedance tomography (mfEIT) system KHU Mark1: impedance spectroscopy and time-difference imaging

International Nuclear Information System (INIS)

Oh, Tong In; Koo, Hwan; Lee, Kyung Heon; Kim, Sang Min; Woo, Eung Je; Lee, Jeehyun; Kim, Sung Wan; Seo, Jin Keun

2008-01-01

Validation and interpretation of reconstructed images using a multi-frequency electrical impedance tomography (mfEIT) requires a conductivity phantom including imaging objects with known complex conductivity (σ + iωε) spectra. We describe imaging experiments using the recently developed mfEIT system called the KHU Mark1 with the frequency range of 10 Hz to 500 kHz. Using a bio-impedance spectroscopy (BIS) system, we first measured complex conductivity spectra of different imaging objects including saline, agar, polyacrylamide, TX151, animal hide gelatin, banana and cucumber. Based on an analysis of how conductivity and permittivity affect measured complex boundary voltages, we suggested a new complex version of a multi-frequency time-difference image reconstruction algorithm. Imaging experiments were conducted to produce time-difference images of the objects at multiple frequencies using the proposed algorithm. Images of a conductor (stainless steel) and an insulator (acrylic plastic) were used to set a common scale bar to display all images. Comparing reconstructed time-difference images at multiple frequencies with measured complex conductivity spectra, we found that they showed an overall similarity in terms of changes in complex conductivity values with respect to frequency. However, primarily due to the limitation of the difference imaging algorithm, we suggest that multi-frequency time-difference images must be interpreted in terms of relative contrast changes with respect to frequency. We propose further imaging studies using biological tissues of known complex conductivity spectra and using human subjects to find clinical applications of the mfEIT system

Geospace ionosphere research with a MF/HF radio instrument on a cubesat

Science.gov (United States)

Kallio, E. J.; Aikio, A. T.; Alho, M.; Fontell, M.; van Gijlswijk, R.; Kauristie, K.; Kestilä, A.; Koskimaa, P.; Makela, J. S.; Mäkelä, M.; Turunen, E.; Vanhamäki, H.

2016-12-01

arctic ionosphere with (1) a new 3D ray tracing model and (2) a new 3D full kinetic electromagnetic simulation. These simulations are used to analyse the origin of the radio waves observed by the MH/HF radio instrument and, consequently, to derive information about the 3D ionosphere and its spatial and temporal variations.

Analysis of compaction shock interactions during DDT of low density HMX

Science.gov (United States)

Rao, Pratap T.; Gonthier, Keith A.

2017-01-01

Deflagration-to-Detonation Transition (DDT) in confined, low density granular HMX occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong combustion-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting dissipative heating within the microstructure during pore collapse. Inert meso-scale simulations of successive shock loading of low density HMX are performed to examine how dissipation and hot-spot formation are affected by the initial density, and the primary and secondary shock strengths. This information is used to formulate an ignition and burn model for low density HMX that accounts for the effect of shock densensitization on burn. Preliminary DDT predictions are presented that illustrate how primary shock strength affects the transition mechanism.

Evaluation of biostimulation and Tween 80 addition for the bioremediation of long-term DDT-contaminated soil.

Science.gov (United States)

Betancur-Corredor, Bibiana; Pino, Nancy J; Cardona, Santiago; Peñuela, Gustavo A

2015-02-01

The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) and its metabolites 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE) were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and pH and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition (B+S) and 94.3% via biostimulation alone (B). Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp., Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy (SEM) allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B+S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5% by natural attenuation after 8 weeks of treatment. Copyright © 2014. Published by Elsevier B.V.

Green-Yellow Electroluminescence from a host-dopant blended system as the active layer in a bilayer polymer light emitting diode: Poly(n-vinyl carbazole) as the host and a new soluble thiophene based copolymer [poly(2,2‧-BT)-co-(3-DDT)] as the dopant

Science.gov (United States)

Shahalizad, Afshin; Ahmadi-Kandjani, Sohrab; Movla, Hossein; Omidi, Hafez; Massoumi, Bakhshali; Zakerhamidi, Mohammad Sadegh; Entezami, Ali Akbar

2014-11-01

A new type of bilayer Polymer Light Emitting Diode (PLED) which emits green-yellow light is reported. In this PLED, a novel thiophene-based copolymer [poly(2,2‧-BT)-co-(3-DDT)] with an excellent electron transporting property has been doped in hole transporting and electron blocking poly(n-vinylcarbazole) (PVK). Formation of type-II heterojunctions among nm-size features in PVK:poly(2,2‧-BT)-co-(3-DDT) blended system makes exciplex and electroplex emissions would be dominant in the Electroluminescence (EL) spectrum of the device. These cross recombinations between electrons in the LUMO of poly(2,2‧-BT)-co-(3-DDT) and holes in the HOMO of PVK is a reason for the low driving voltage of the PLED because there is no need for the charge carriers to hop or tunnel to the adjacent polymer. Morphological investigations demonstrate that the mixing degree between the components is high, favoring formation of exciplexes and electroplexes at the interface of the components.

Global Status of DDT and Its Alternatives for Use in Vector Control to Prevent Disease

NARCIS (Netherlands)

Berg, van den H.

2009-01-01

Objective - I review the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, along with current evidence on its benefits and risks in relation to the available alternatives. Data sources and extraction - Contemporary data on DDT use were largely obtained from

MF-Swift simulation study using benchmark data

NARCIS (Netherlands)

Jansen, S.T.H.; Verhoeff, L.; Cremers, R.; Schmeitz, A.J.C.; Besselink, I.J.M.

2005-01-01

The accuracy of tyre models depends to a large extent on the measurement data used to assess model parameters. The MF-Swift tyre model parameters can be identified or estimated from various combinations of experimental data. The amount and required accuracy of the measurement data can be selected

Simultaneous presence of DDT and pyrethroid residues in human breast milk from a malaria endemic area in South Africa

Energy Technology Data Exchange (ETDEWEB)

Bouwman, H. [School for Environmental Sciences and Development, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom 2520 (South Africa)]. E-mail: drkhb@puk.ac.za; Sereda, B. [Agricultural Research Council, Plant Protection Research Institute, Private Bag X134 Queenswood, Pretoria 0121 (South Africa); Meinhardt, H.M. [South African Bureau of Standards, Testing and Conformity Services (Pty) Ltd, Private Bag X191, Pretoria 0001 (South Africa)

2006-12-15

DDT and pyrethroids were determined in 152 breast-milk samples from three towns in KwaZulu-Natal, South Africa, one of which had no need for DDT for malaria control. All compounds were found present in breast milk. Primiparae from one town had the highest mean {sigma}DDT whole milk levels (238.23 {mu}g/l), and multiparae from the same town had the highest means for permethrin (14.51 {mu}g/l), cyfluthrin (41.74 {mu}g/l), cypermethrin (4.24 {mu}g/l), deltamethrin (8.39 {mu}g/l), and {sigma}pyrethroid (31.5 {mu}g/l), most likely derived from agriculture. The ADI for DDT was only exceeded by infants from one town, but the ADI for pyrethroids was not exceeded. Since the ADI for DDT was recently reduced from 20 to 10 {mu}g/kg/bw, we suggest that this aspect be treated with concern. We therefore raise a concern based on toxicant interactions, due to the presence of four different pyrethroids and DDT. Breastfeeding however, remains safe under prevailing conditions. - The simultaneous presence of DDT and pyrethroid residues in breast milk raises the question of infant exposure and safety.

Magnitude of [14C] DDT residues in stored dried fish and pre-cooking processing effect on their removal

International Nuclear Information System (INIS)

Rahman, M.; Khatoon, J.; Matin, M.A.; Main, A.J.

1998-01-01

Residues of 14 C-DDT in stored dried fish was determined under ambient conditions for a 6 month period. Immediately after treatment, about 40% of the applied DDT was eliminated from surface of the dried fish with water washing. However, such removal was reduced to about 26% on storage for 6 months. Boiling of dried fish in water resulted in further removal of about 16% residues. In boiled dried fish, about 14% residues might remain and this could be removed by Soxhlet extraction. Surface extraction with hexane yielded about 80% of the residues immediately after treatment and the extractable residues decreased to about half the initial value of 6 months' storage. Dried fish residues, on surface extraction with water or hexane, when subjected to exhaustive Soxhlet extraction with methanol was found to result in further recovery of about 39-49% and 17-32%, respectively. Bound DDT residues were found to be about 5% in water washed dried fish samples and about 1.5% in case of hexane-extracted samples. Degradation of parent DDT to DDE and DDD was found. Maximum values of 16.58% DDE and 21.6% DDD were found in dried fish stored for 6 months. (author)

MF Scales: Instruments of Male Chauvinism or Responsible Tools of the Psychologist?

Science.gov (United States)

Harmon, Lenore W.

A study is made of the validity of the use of MF scales. It is pointed out that femininity is often a liability in the psychologist's office. Clients who have MF scores considered to be more appropriate for the opposite sex are threatened by them. If the clinician assumes the client has an abnormal score, the ensuing therapy usually will be…

Molecular genetic tests for JAK2V617F, Exon12_JAK2 and MPLW515K/L are highly informative in the evaluation of patients suspected to have BCR-ABL1-negative myeloproliferative neoplasms.

Science.gov (United States)

dos Santos, Marcos Tadeu; Mitne-Neto, Miguel; Miyashiro, Kozue; Chauffaille, Maria de Lourdes L Ferrari; Rizzatti, Edgar Gil

2014-02-01

Polycythaemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (MF), are the most common myeloproliferative neoplasms (MPN) in patients without the BCR-ABL1 gene rearrangement. They are caused by clonal expansion of haematopoietic stem cells and share, as a diagnostic criterion, the identification of JAK2V617F mutation. Classically, when other clinical criteria are present, a JAK2V617F negative case requires the analysis of Exon12_JAK2 for the diagnosis of PV, and of MPL515K/L mutations for the diagnosis of ET and MF. Here, we evaluated 78 samples from Brazilian patients suspected to have MPN, without stratification for PV, ET or MF. We found that 28 (35.9%) are JAK2V617F carriers; from the 50 remaining samples, one (2%) showed an Exon12_JAK2 mutation, and another (2%) was positive for MPLW515L mutation. In summary, the investigation of JAK2V617F, Exon12_JAK2 and MPLW515K/L was relevant for the diagnosis of 38.4% of patients suspected to have BCR-ABL1-negative MPN, suggesting that molecular genetic tests are useful for a quick and unequivocal diagnosis of MPN.

Cloning and expression analysis of a new anther-specific gene CaMF4 in Capsicum annuum.

Science.gov (United States)

Hao, Xuefeng; Chen, Changming; Chen, Guoju; Cao, Bihao; Lei, Jianjun

2017-03-01

Our previous study on the genic male sterile-fertile line 114AB of Capsicum annuum indicated a diversity of differentially expressed cDNA fragments in fertile and sterile lines. In this study, a transcript-derived fragment (TDF), male fertile 4 (CaMF4) was chosen for further investigation to observe that this specific fragment accumulates in the flower buds of the fertile line. The full genomic DNA sequence of CaMF4 was 894 bp in length, containing two exons and one intron, and the complete coding sequence encoded a putative 11.53 kDa protein of 109 amino acids. The derived protein of CaMF4 shared similarity with the members of PGPS/D3 protein family. The expression of CaMF4 was detected in both the flower buds at stage 8 and open flowers of the male fertile line. In contrast to this observation, expression of CaMF4 was not detected in any organs of the male sterile line. Further analysis revealed that CaMF4 was expressed particularly in anthers of the fertile line. Our results suggest that CaMF4 is an anther-specific gene and might be indispensable for anther or pollen development in C. annuum.

Persistence of DDT and parathion residues on a plant surface as influenced by weather factors

NARCIS (Netherlands)

Fahmy, H.S.M.

1961-01-01

The decay of DDT and parathion deposits under the influence of temperature, rain and ultraviolet radiation was described. Temperature and solar radiation were the main factors limiting the residual effect. High mean temperatures were more important than high maxima.

DDT residues were more

Comparative effects of DDT, allethrin, dieldrin and aldrin-transdiol on sense organs of Xenopus laevis

NARCIS (Netherlands)

Akkermans, L.M.A.; Bercken, J. van den; Versluijs-Helder, M.

1975-01-01

The effects of DDT, allethrin, dieldrin and aldrin-transdiol were studied in two different sense organs of Xenopus laevis; the lateral-line organ and the cutaneous touch receptors. DDT and allethrin produced pronounced repetitive firing in both preparations. Dieldrin and aldrin-transdiol, on the

MicroRNA Expression in Early Mycosis Fungoides Is Distinctly Different from Atopic Dermatitis and Advanced Cutaneous T-Cell Lymphoma

DEFF Research Database (Denmark)

Ralfkiaer, Ulrik; Lindahl, Lise Maria; Litman, Thomas

2014-01-01

Mycosis fungoides (MF) is the most common variant of cutaneous T-cell lymphoma (CTCL). MF is characterized by chronic inflammation dominated by cluster of differentiation 4-positive (CD4(+)) T-cells and T helper 2 cytokines, and as the malignant T-cell clone is initially elusive, early diagnosis...... is often impossible. MF usually takes an indolent course, but for unknown reasons may turn into an aggressive disease with a poor prognosis. Herein, we used a global quantitative real-time polymerase chain reaction platform to study microRNA (miR) expression in patients with early MF (n=13), more advanced...... CTCL (n=42), and atopic dermatitis (AD, n=20). Thirty-eight miRs were differentially expressed (≥2-fold) in early MF vs. AD and 36 in early MF vs. more advanced disease. miRs that distinguish early MF from AD included both up-regulated (miR-155, miR-146a, 146b-5p, miR-342-3p, let-7i*) and down...

DDT poisoning of big brown bats, Eptesicus fuscus, in Hamilton, Montana.

Science.gov (United States)

Buchweitz, John P; Carson, Keri; Rebolloso, Sarah; Lehner, Andreas

2018-06-01

Dichlorodiphenyltrichloroethane (DDT) is an insecticidal organochlorine pesticide with; known potential for neurotoxic effects in wildlife. The United States Environmental Protection Agency (US EPA) registration for this pesticide has been cancelled and there are currently no federally active products that contain this ingredient in the U.S. We present a case of a colony of big brown bats (E. Fuscus) found dead in the attic roost of an administrative building; in the city of Hamilton, Montana from unknown cause. DDT and its metabolites; dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were detected in bat tissues by gas chromatography/mass spectrometry (GC-MS) and quantified by gas chromatography tandem quadrupole mass spectrometry (GC-MS/MS). Concentrations of 4081 ppm DDT and 890 ppm DDE wet weight were found in the brain of one bat and are the highest reported concentrations in such a mortality event to date. This case emphasizes the importance of testing wildlife mortalities against a comprehensive panel of toxicologic agents including persistent organic pollutants in the absence of other more common disease threats. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hybrid MF and membrane bioreactor process applied towards water and indigo reuse from denim textile wastewater.

Science.gov (United States)

Couto, Carolina Fonseca; Marques, Larissa Silva; Balmant, Janine; de Oliveira Maia, Andreza Penido; Moravia, Wagner Guadagnin; Santos Amaral, Miriam Cristina

2018-03-01

This work investigates the application of a microfiltration (MF)-membrane bioreactor (MBR) hybrid process for textile dyeing process wastewater reclamation. The indigo blue dye was efficiently retained by the MF membrane (100%), which allows its recovery from the concentrate stream. MF promotes 100% of colour removal, and reduces the chemical oxygen demand (COD) and conductivity by about 65% and 25%, respectively, and improves the wastewater biodegradability. MF flux decline was mostly attributed to concentration polarization and the chemical cleaning was efficient enough to recover initial hydraulic resistance. The MBR provides to be a stable process maintaining its COD and ammonia removal efficiency (73% and 100%, respectively) mostly constant throughout and producing a permeate that meets the reuse criteria for some industry activities, such as washing-off and equipment washdown. The use of an MF or ultrafiltration (UF) membrane in the MBR does not impact the MBR performance in terms of COD removal. Although the membrane of MBR-UF shows permeability lower than MBR-MF membrane, the UF membrane contributes to a more stable operation in terms of permeability.

The Amelioration of Myelofibrosis with Thrombocytopenia by a JAK1/2 Inhibitor, Ruxolitinib, in a Post-polycythemia Vera Myelofibrosis Patient with a JAK2 Exon 12 Mutation.

Science.gov (United States)

Ikeda, Kazuhiko; Ueda, Koki; Sano, Takahiro; Ogawa, Kazuei; Ikezoe, Takayuki; Hashimoto, Yuko; Morishita, Soji; Komatsu, Norio; Ohto, Hitoshi; Takeishi, Yasuchika

2017-01-01

Less than 5% of patients with polycythemia vera (PV) show JAK2 exon 12 mutations. Although PV patients with JAK2 exon 12 mutations are known to develop post-PV myelofibrosis (MF) as well as PV with JAK2V617F, the role of JAK inhibitors in post-PV MF patients with JAK2 exon 12 mutations remains unknown. We describe how treatment with a JAK1/2 inhibitor, ruxolitinib, led to the rapid amelioration of marrow fibrosis, erythrocytosis and thrombocytopenia in a 77-year-old man with post-PV MF who carried a JAK2 exon 12 mutation (JAK2H538QK539L). This case suggests that ruxolitinib is a treatment option for post-PV MF in patients with thrombocytopenia or JAK2 exon 12 mutations.

Widespread Pyrethroid and DDT Resistance in the Major Malaria Vector Anopheles funestus in East Africa Is Driven by Metabolic Resistance Mechanisms

Science.gov (United States)

Mulamba, Charles; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Barnes, Kayla G.; Mukwaya, Louis G.; Birungi, Josephine; Wondji, Charles S.

2014-01-01

Background Establishing the extent, geographical distribution and mechanisms of insecticide resistance in malaria vectors is a prerequisite for resistance management. Here, we report a widespread distribution of insecticide resistance in the major malaria vector An. funestus across Uganda and western Kenya under the control of metabolic resistance mechanisms. Methodology/Principal Findings Female An. funestus collected throughout Uganda and western Kenya exhibited a Plasmodium infection rate between 4.2 to 10.4%. Widespread resistance against both type I (permethrin) and II (deltamethrin) pyrethroids and DDT was observed across Uganda and western Kenya. All populations remain highly susceptible to carbamate, organophosphate and dieldrin insecticides. Knockdown resistance plays no role in the pyrethroid and DDT resistance as no kdr mutation associated with resistance was detected despite the presence of a F1021C replacement. Additionally, no signature of selection was observed on the sodium channel gene. Synergist assays and qRT-PCR indicated that metabolic resistance plays a major role notably through elevated expression of cytochrome P450s. DDT resistance mechanisms differ from West Africa as the L119F-GSTe2 mutation only explains a small proportion of the genetic variance to DDT resistance. Conclusion The extensive distribution of pyrethroid and DDT resistance in East African An. funestus populations represents a challenge to the control of this vector. However, the observed carbamate and organophosphate susceptibility offers alternative solutions for resistance management. PMID:25333491

Temperature-controlled down-conversion luminescence behavior of Eu3+ -doped transparent MF2 (M = Ba, Ca, Sr) glass ceramics.

Science.gov (United States)

Zhou, B; E, C Q; Bu, Y Y; Meng, L; Yan, X H; Wang, X F

2017-03-01

Eu 3 + -doped transparent glass ceramics containing MF 2 (M = Ba, Ca, Sr) nanocrystals were fabricated using a melt-quenching method, and the resulting structures were studied using X-ray diffraction. Levels 5 D 1 and 5 D 0 of Eu 3 + ions were verified as thermally coupled levels using the fluorescence intensity ratio method. The fluorescence intensity ratios, optical temperature sensitivity and thermal quenching ratios of the transparent glass ceramics were studied as a function of temperature. With an increase in temperature, the relative sensitivity (S R ) decreased sharply at first, then slowly increased, before finally decreasing. The minimum S R values of GCBaF 2 (GCB), GCCaF 2 (GCC) and GCSrF 2 (GCS) were 2.8 × 10 -4 , 0.8 × 10 -4 and 1.9 × 10 - 4  K -1 at 360, 269 and 319 K, respectively. Glass ceramics with an intense emission intensity can be used to convert the measured spectrum into temperature and may have an important role in temperature detectors. Copyright © 2016 John Wiley & Sons, Ltd.

Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

Science.gov (United States)

Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

2017-07-01

The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

On the deflagration-to-detonation transition (DDT) process with added energetic solid particles for pulse detonation engines (PDE)

Science.gov (United States)

Nguyen, V. B.; Li, J.; Chang, P.-H.; Phan, Q. T.; Teo, C. J.; Khoo, B. C.

2018-01-01

In this paper, numerical simulations are performed to study the dynamics of the deflagration-to-detonation transition (DDT) in pulse detonation engines (PDE) using energetic aluminum particles. The DDT process and detonation wave propagation toward the unburnt hydrogen/air mixture containing solid aluminum particles is numerically studied using the Eulerian-Lagrangian approach. A hybrid numerical methodology combined with appropriate sub-models is used to capture the gas dynamic characteristics, particle behavior, combustion characteristics, and two-way solid-particle-gas flow interactions. In our approach, the gas mixture is expressed in the Eulerian frame of reference, while the solid aluminum particles are tracked in the Lagrangian frame of reference. The implemented computer code is validated using published benchmark problems. The obtained results show that the aluminum particles not only shorten the DDT length but also reduce the DDT time. The improvement of DDT is primarily attributed to the heat released from surface chemical reactions on the aluminum particles. The temperatures associated with the DDT process are greater than the case of non-reacting particles added, with an accompanying rise in the pressure. For an appropriate range of particle volume fraction, particularly in this study, the higher volume fraction of the micro-aluminum particles added in the detonation chamber can lead to more heat energy released and more local instabilities in the combustion process (caused by the local high temperature), thereby resulting in a faster DDT process. In essence, the aluminum particles contribute to the DDT process of successfully transitioning to detonation waves for (failure) cases in which the fuel gas mixture can be either too lean or too rich. With a better understanding of the influence of added aluminum particles on the dynamics of the DDT and detonation process, we can apply it to modify the geometry of the detonation chamber (e.g., the length of

Concentrations and human health risk assessment of DDT and its metabolites in free-range and commercial chicken products from KwaZulu-Natal, South Africa.

Science.gov (United States)

Thompson, L A; Ikenaka, Y; Yohannes, Y B; van Vuren, J J; Wepener, V; Smit, N J; Darwish, W S; Nakayama, S M M; Mizukawa, H; Ishizuka, M

2017-11-01

Organochlorine pesticides such as dichlorodiphenyltrichloroethane (DDT) have been used in agriculture and for disease control purposes over many decades. Reports suggest that DDT exposure may result in a number of adverse effects in humans. In the KwaZulu-Natal Province of South Africa, DDT is sprayed annually in homes (indoor residual spraying) to control the mosquito vector of malaria. In the northern part of the Province, samples of free-range chicken meat (n = 48) and eggs (n = 13), and commercially produced chicken meat (n = 6) and eggs (n = 11), were collected and analysed. Of the free-range chicken meat samples, 94% (45/48) contained DDTs (ΣDDTs median 6.1 ng/g wet weight [ww], maximum 79.1 ng/g ww). Chicken egg contents were also contaminated (ΣDDTs in free-range eggs median 9544 ng/g ww, maximum 96.666 ng/g ww; and in commercial eggs median 1.3 ng/g ww, maximum 4.6 ng/g ww). The predominant DDT congener detected was p,p'-DDE in both free-range meat (>63%) and eggs (>66%), followed by p,p'-DDT and then p,p'-DDD. Based on estimated daily intake values, calculated human risk ratio (carcinogenic) values were >1 for DDTs detected in both free-range chicken products. Consumption of free-range eggs poses a particularly high health risk.

Miltefosine inhibits Chikungunya virus replication in human primary dermal fibroblasts [version 1; referees: 2 approved, 1 approved with reservations

Directory of Open Access Journals (Sweden)

Anuj Sharma

2018-01-01

Full Text Available Background: Chikungunya virus (CHIKV is a re-emerging pathogen that has caused widespread outbreaks affecting millions of people around the globe. Currently, there is no specific therapeutic drug against CHIKV, with symptomatic treatment only to manage the disease. Pi3-akt signaling has been implicated in infection of several viruses including that of CHIKV. Effect of Pi3-akt signaling inhibitors on CHIKV replication was evaluated in this study. Methods: Human primary dermal fibroblast cells were treated with inhibitors of the Pi3-akt signaling pathway. Suppression of CHIKV replication was evaluated as reduction in virus titer in cell supernatants. Effect of miltefosine (MF on CHIKV replication was evaluated in pre and post treatment regimen. Inhibition of virus replication was determined by cell growth, virus titer and western blot. Results: Inhibition of Akt-phosphorylation significantly inhibited CHIKV replication. No effect on CHIKV replication was observed after treatment with Pi3-kinase and mTOR activation inhibitors. Further, MF, an FDA-approved Akt-inhibitor, inhibited CHIKV replication in pre- and post-infection treatment regimens. Conclusion: Data suggests that Akt-phosphorylation can be an amenable target of therapy against CHIKV infection. This is the first study to show inhibition of CHIKV replication by MF, and presents a case for further development of MF as an anti-CHIKV drug.

Impact of climate fluctuations on deposition of DDT and hexachlorocyclohexane in mountain glaciers: Evidence from ice core records

International Nuclear Information System (INIS)

Wang Xiaoping; Gong Ping; Zhang, Qianggong; Yao Tandong

2010-01-01

How do climate fluctuations affect DDT and hexachlorocyclohexane (HCH) distribution in the global scale? In this study, the interactions between climate variations and depositions of DDT and HCH in ice cores from Mt. Everest (the Tibetan Plateau), Mt. Muztagata (the eastern Pamirs) and the Rocky Mountains were investigated. All data regarding DDT/HCH deposition were obtained from the published results. Concentrations of DDT and HCH in an ice core from Mt. Everest were associated with the El Nino-Southern Oscillation. Concentrations of DDT in an ice core from Mt. Muztagata were significantly correlated with the Siberia High pattern. Concentrations of HCH in an ice core from Snow Dome of the Rocky Mountains responded to the North Atlantic Oscillation. These associations suggested that there are some linkages between climate variations and the global distribution of persistent organic pollutants. - Our study approves the potential contribution of ice core records of POPs to transport mechanisms of POPs.

The Influence of Brightness on Functional Assessment by mfERG

DEFF Research Database (Denmark)

Christiansen, A T; Kiilgaard, J F; Smith, M

2012-01-01

To determine the effect of membrane brightness on multifocal electroretinograms (mfERGs), we implanted poly lactic-co-glycolic acid (PLGA) membranes in the subretinal space of 11 porcine eyes. We compared membranes with their native shiny white color with membranes that were stained with a blue dye...... (Brilliant Blue). Histological and electrophysiological evaluation of the overlying retina was carried out 6 weeks after implantation. Histologically, both white and blue membranes degraded in a spongiform manner leaving a disrupted outer retina with no preserved photoreceptor segments. Multifocal ERG...... when the adjacent photoreceptors are missing. Functional assessment with mfERG in scaffold implant studies should therefore be evaluated with care....

The effect of larval nutritional deprivation on the life history and DDT resistance phenotype in laboratory strains of the malaria vector Anopheles arabiensis

Science.gov (United States)