Disease relevance of DDT

• CONCLUSIONS: Our data do not support the hypothesis that exposure to DDT and PCBs increases the risk of breast cancer [1].
• DDT-induced feminization of gull embryos [2].
• IMPLICATIONS: These results may indicate that DDT can cause pancreatic cancer in humans under circumstances of heavy and prolonged exposure [3].
• INTERPRETATION: The findings strongly suggest that DDT use increases preterm births, which is a major contributor to infant mortality [4].
• Several studies suggest that there may be an association between the agricultural use of the organochlorine 1,1,1-trichloro-2,2'bis(p-chlorophenyl)ethane (DDT) and increased risk of non-Hodgkin lymphoma [5].

Psychiatry related information on DDT

• DDT-treated rats had a significantly lower mammary tumor incidence, prolonged tumor latency period, and fewer tumors per rat than did the control group [6].
• EDA-imprinted sol-gels, deposited as films on glass microscope slides, were shown to quantitatively detect DDT in water to a limit-of-detection of 50 ppt with a response time of <60 s [7].
• Avian species thus reflect biological magnification of BHC and DDT residues, presumably due to their food habits [8].
• These findings are discussed in relation to previous reports of the behavior of An. minimus s.l., particularly in light of suggestions that An. minimus s.l. has changed its feeding behavior in response to DDT spraying [9].
• Increased spontaneous locomotor activity in the fiddler crab, Uca pugilator, after exposure to a sublethal concentration of DDT [10].

High impact information on DDT

• Massachusetts Department of Public Health. Bats, rabies and DDT [11].
• Genetic recombination and directional selection for DDT resistance in Drosophila melanogaster [12].
• Asymmetrical currents and sodium currents in Ranvier nodes exposed to DDT [13].
• The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene to carbon dioxide [14].
• 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 [2].

Chemical compound and disease context of DDT

• PURPOSE: This blinded study was designed to determine whether exposure to PCBs and to DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene], the major metabolite of DDT, is associated with breast cancer risk in women [15].
• Two DDT derivatives, Ethylan and DDD, were additionally associated with pancreatic cancer (RR = 5.0 and 4.3, respectively); exposures to these two chemicals were correlated, and it was not possible to determine whether each acted independently of the other [3].
• To explore cycling through these alternate rate-limiting steps, we determined kinetic parameters for single-nucleotide incorporation by HXB2R HIV-1 RT with chain-terminating nucleotide substrates 3'-azido-3'-deoxythymidine triphosphate (AZTTP) and dideoxythymidine triphosphate on a homopolymeric T.P system, poly(rA)-oligo(dT)16 [16].
• Zidovudine (azido dideoxythymidine) inhibits characteristic early alterations of lymphoid cell populations in retrovirus-induced murine AIDS [17].
• HU at lower concentrations (< 0.1 mM) was found to potentiate the antiviral activity of 2',3'-dideoxyinosine (ddl), 3'-azido-2',3'- dideoxythymidine, and 2',3'-dideoxycytidine against HIV-1, with the potentiation being ddl greater than 3'-azido-2',3'- dideoxythymidine = 2',3'-dideoxycytidine [18].

Biological context of DDT

• The chlorinated hydrocarbons DDT and PCB's (polychlorinated biphenyls), ubiquitous pollutants of the marine environment, have been observed to reduce the cell division rate of marine phytoplankton, thereby indirectly reducing the total photosynthetic carbon fixation in treated cultures [19].
• Increased risks of NHL were also observed among those with occupational exposure to organochlorine insecticides, such as DDT [1.82 (1.04-3.2)] and organic solvents [1.35 (1.06-1.7)], and to other chemicals typically encountered in the agricultural, forestry, or wood products industries [20].
• DDT -- a novel domain in different transcription and chromosome remodeling factors [21].
• Homology-based sequence analyses have revealed the presence of a novel domain (DDT) in bromodomain PHD finger transcription factors (BPTFs), chromatin remodeling factors of the BAZ-family and other putative nuclear proteins [21].
• Thus we must reject the hypothesis that the insertion of a long terminal repeat leads to DDT susceptibility in Drosophila [22].

Anatomical context of DDT

• We compared the effects of organochlorines belonging to the DDT and PCB families, alone and in combination, for their ability to influence the estrogen receptor-mediated activities in preneoplastic breast epithelial cells and breast cancer cells [23].
• Occupational exposure to DDT may increase the risk of pancreas cancer [24].
• In contrast, in the TG-resistant Syrian hamster smooth muscle cell line DDT/TG 4 microM, a T --> C change at nucleotide 767 introduces a Phe256 --> Ser mutation at that position [25].
• Effects of aphidicolin and/or 2',3'-dideoxythymidine on DNA repair induced in HeLa cells by four types of DNA-damaging agents [26].
• They share many characteristics with DDT, including a negative temperature coefficient, and knockdown and killing activity resulting from action against the sodium channels of the peripheral and central nervous systems [27].

Associations of DDT with other chemical compounds

• Female Sprague-Dawley rats, 36 days old, were pretreated for 2 weeks either with 100 ppm 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) or 250 ppm S-(1,2-dicarbeth-oxyethyl)OO-dimethyldithiophosphate (Malathion) in the diet [6].
• The reaction is not blocked by dideoxythymidine triphosphate, suggesting that DNA polymerase alpha is involved [28].
• The principal metabolite of both DDT and DDD is 2,2-bis(p-chlorophenyl) acetic acid [29].
• With this technique, the involvements of DNA polymerases in DNA repair of damage by dimethyl sulfate, UV irradiation, neocarzinostatin, and bleomycin were studied in HeLa cells with the aid of the DNA polymerase inhibitors aphidicolin and 2',3'-dideoxythymidine [26].
• Contrary to what is generally assumed, diphospho- and triphospho- derivatives of azidothymidine as well as of dideoxyadenosine and dideoxythymidine are very poor substrates for NDP kinase [30].

Gene context of DDT

• The interaction of Acf1 with ISWI requires a DDT domain, which has been found in a variety of transcription and chromatin-remodeling factors [31].
• High expression of Cyp6g1, a cytochrome P450 gene, does not necessarily confer DDT resistance in Drosophila melanogaster [32].
• The level of expression of the Cyp6a2 gene is much higher in the DDT-resistant 91-R strain than in the susceptible 91-C strain of Drosophila melanogaster (Waters et al. (1992b) Proc. Natl. Acad. Sci. USA, 89, 4855-4859) [33].
• PR mRNA expression in MCF-7 cells was up regulated after administration of COU and DDT, whereas treatment with BPA and OCT did not effect PR mRNA expression [34].
• Point mutations in the Drosophila sodium channel gene para associated with resistance to DDT and pyrethroid insecticides [35].

Analytical, diagnostic and therapeutic context of DDT

• Cross-sectional study of a community with exceptional exposure to DDT [36].
• Using flow cytometry technology and multiparameter analyses, we report early and characteristic alterations in lymphoid cell profile in spleen and lymph nodes due to LP-BM5 retrovirus disease (murine AIDS (MAIDS)) and the effect of azido dideoxythymidine, a nucleoside inhibitor, on these changes [17].
• A case-control study of pancreas cancer in residents, aged 30-79 years, of 18 counties in southeastern Michigan was conducted to investigate the risks of exposure to DDT and related materials in the general population [37].
• Western blots using antibodies raised against these GSTs indicated that the expression of GSTE2-2 is elevated in a DDT-resistant strain of A. gambiae [38].
• The highest tumour incidence was recorded in the group of mice receiving DDT by subcutaneous injections [39].

References