Faqja 1 nga 142 rezultatet
Thymic atrophy and humoral immunosuppression by certain polychlorinated biphenyls is associated with the aromatic hydrocarbon (Ah) receptor in mice. We examined the relationship between these two toxic effects. 3,3',4,4'-Tetrachlorobiphenyl (TCB), which causes immunosuppression and thymic atrophy,
Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that have been linked to oxidative and other toxic effects in both humans and wildlife. Due to recent environmental health concerns at a PCB contaminated Superfund site near Raleigh, NC, we used a common clam species
Polychlorinated biphenyls (PCBs) are a class of organic pollutants that have been linked to pancreatic disease. However, their role in affecting the exocrine function of pancreas and the underlying mechanism remains elusive. In the present study, male C57 mice were treated with Aroclor 1254, a
From the 1940s through 1977, at least 590,000kg of polychlorinated biphenyls (PCBs) were released into the Hudson River from General Electric manufacturing plants located in Hudson Falls and Fort Edward, New York. In 1984, the U.S. Environmental Protection Agency designated a nearly 322km reach as
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and its congeners bind to the Ah receptor and are known to cause thymic atrophy in most experimental animal species and also to inhibit lymphoid development in the embryonic thymus (T-cells) and in the bursa of Fabricius of chick embryos (B-cells). The
Diseases due to the degeneration of the liver and various other internal organs were the major cause of the exceedingly high chick mortality in lesser black-backed gulls (Larus fuscus fuscus) in the central Gulf of Finland, Baltic Sea, during 1991-1993. The same symptoms were found in chicks of
Polychlorinated biphenyls (PCBs) were widely used in various industrial applications. Research confirmed that some PCB congeners degrade slowly in the environment and can build up in the food chain. Poisoning episodes in Asia were initially attributed to PCB-contaminated oil, although subsequent
Rats were fed with a diet containing Phenoclor DP6, a French commercial polychlorinated biphenyl (PCB) mixture, for 30 days. Diet PCB levels were 10, 100, 500 and 1000 ppm (wet weight). At 500 ppm, a 50 per cent mortality was found after 8 days, while a 100 per cent mortality was noted after 6 days
A commercial polychlorinated biphenyl (PCB) mixture containing 42% chlorine by weight was fed at the dose level of 20 ppm to 3rd-litter sows throughout gestation and nursing. Treated sows differed significantly (0.05% level) from control sows in the number of live pigs they farrowed. Treated sows
Several studies have reported a low inducibility of hepatic cytochrome P4501A (CYP1A) activity in European flounder (Platichthys flesus) following exposure to mixtures of polychlorinated biphenyls (PCBs). Here we report on mechanistic studies toward understanding this low CYP1A inducibility of
Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that can severely disrupt the synthesis and secretion of endocrine hormones. To investigate the effects of 2,3',4,4',5-pentachlorobiphenyl (PCB118) on thyroid structure and function, 40 male Wistar rats were divided into 4
The arylhydrocarbon receptor (AhR) is a ligand-activated transcription factor and mediates carcinogenic, teratogenic, and toxic effects of xenobiotics such as dioxin and coplanar polychlorinated biphenyls. The AhR nuclear translocator (ARNT) is involved in AhR signal transduction. We have analyzed
The in vivo quantitative structure-activity relationships (QSARs) for several polychlorinated biphenyls (PCBs) were determined in the immature male Wistar rat. The ED25 and ED50 values for hepatic microsomal aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) induction as well
Toxicosis was induced in pregnant Holstein-Friesian heifers by giving polybrominated biphenyls a in gelatin capsules at the rate of 25 g/day. Initially, this dosage was approximately 67 mg/kg of body weight. Clinical signs were anorexia, excessive lacrimation and salivation, diarrhea, emaciation,
Polychlorinated biphenyls (PCBs) are persistent toxic pollutants occurring as complex mixtures in the environment. Humans are known genetically to have > 60-fold differences in hepatic cytochrome P450 1A2 (CYP1A2) levels and > 12-fold differences in aryl hydrocarbon receptor (AHR) affinity, both of