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Bulletin of Environmental Contamination... Jun 1989
Topics: Air Pollutants; Carbamates; Phenylcarbamates
PubMed: 2743023
DOI: 10.1007/BF01701632 -
Bulletin of Environmental Contamination... Jan 1989
Topics: Aircraft; Carbamates; Fenitrothion; Phenylcarbamates; Plants
PubMed: 2924004
DOI: 10.1007/BF01699201 -
Journal of Toxicology and Environmental... 1988Interaction of two potential immunosuppressive factors, sublethal pesticide exposure and viral inhibition of lymphocyte mitogenesis, was examined in mixed lymphocyte...
Interaction of two potential immunosuppressive factors, sublethal pesticide exposure and viral inhibition of lymphocyte mitogenesis, was examined in mixed lymphocyte reaction (MLR). Inbred (C57Bl/6 x A/J)F mice, semisusceptible to mouse hepatitis virus 3 (MHV3) infection were exposed to selected pesticides and subsequently infected with the MHV3 virus. The mortality of animals was examined as a function of pesticide exposure. Two pesticides were selected for further studies: the organochlorine pesticide dieldrin, which increased the cumulative mortality of animals, and the carbamate pesticide aminocarb, which did not affect the virus-induced cumulative mortality of animals. Spleen lymphocytes from dieldrin- and aminocarb-exposed C57Bl/6 mice (susceptible to MHV3 infection) were used as responder cells in one-way MLR. A marked immunosuppression of the MLR proliferative response was observed in the dieldrin group, whereas sublethal exposure to aminocarb did not affect the in vitro MLR response. The MLR cultures were subsequently infected in vitro with the MHV3 virus, which resulted in a time-dependent and virus dose-dependent inhibition of lymphocyte proliferation. However, no synergism was observed with the addition of either the MHV3 virus-induced inhibition of in vitro MLR lymphoproliferative response or dieldrin-related immunosuppression, since in vitro MHV3 infection of cells from dieldrin-exposed mice did not aggravate the dieldrin-related immunosuppression. In addition, no "hidden" aminocarb-related damage of the lymphoproliferative response was noted, as the kinetics of the virus-induced inhibition in the aminocarb group were analogous to the control. In conclusion, dieldrin-induced immunosuppression of the cellular immune response, rather than MHV3 virus-induced inhibition of lymphoproliferative activity itself, was the primary factor potentially responsible for the impaired cellular response. Furthermore, the data support the observation that cell-mediated immunity can be a potential target for the adverse effects of pesticide exposure.
Topics: Animals; Carbamates; Cells, Cultured; Dieldrin; Female; Immunity, Cellular; Liver; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Phenylcarbamates; Spleen; Viral Proteins; Virus Diseases
PubMed: 3418741
DOI: 10.1080/15287398809531192 -
Mutation Research May 1987The effect of two different mutations, one involving an alpha-tubulin (tubA) and the other a beta-tubulin (benA33) gene, on somatic segregation has been investigated in...
The effect of two different mutations, one involving an alpha-tubulin (tubA) and the other a beta-tubulin (benA33) gene, on somatic segregation has been investigated in diploid strains of A. nidulans. Both mutations, particularly benA33, increase the level of spontaneous chromosomal mis-distribution (CMD) phenomena, without affecting the frequency of crossing-over. The employment of homozygous strains for each of the two mutations in sensitivity tests toward various chemicals, allowed the clear identification of those interfering with microtubule assembly-disassembly processes (i.e. chloral hydrate, diamide, aminocarb, N-ethyl-maleimide, p-chlormercuribenzoate). Such compounds turned out to be very efficient and specific inducers of CMD in a somatic segregation assay performed using the wild-type strain P1. The same assay, when carried out with some of these compounds but employing a tubA/tubA strain, revealed a marked proneness toward CMD to be associated with such mutation, which is known to confer microtubule hypostability.
Topics: Aspergillus; Chromosome Aberrations; Genes, Fungal; Microtubules; Mitosis; Mutagenicity Tests; Mutation; Temperature; Tubulin
PubMed: 3574324
DOI: 10.1016/0027-5107(87)90083-2 -
Journal of Toxicology and Environmental... 1987The dermal penetration of 14C-ring-labeled fenitrothion and aminocarb was determined in rats and rhesus monkeys. In monkeys, 49 +/- 4% (t1/2 = 14 h) of the fenitrothion...
The dermal penetration of 14C-ring-labeled fenitrothion and aminocarb was determined in rats and rhesus monkeys. In monkeys, 49 +/- 4% (t1/2 = 14 h) of the fenitrothion and 74 +/- 4% (t1/2 = 25 h) of aminocarb were absorbed from the forehead, while 21 +/- 10% (t1/2 = 17 h) fenitrothion and 37 +/- 14% (t1/2 = 31 h) aminocarb were absorbed from ventral forearm. Monkey forehead was 2.3 times and 2.0 times more permeable than the forearm for fenitrothion and aminocarb, respectively. In rats, 84 +/- 12% (t1/2 = 20 h) of the fenitrothion and 88 +/- 6% (t1/2 = 17 h) aminocarb was absorbed from the middorsal region. These results were corrected for incomplete excretion by intramuscular injections of fenitrothion in money, 95 +/- 7% (t1/2 = 12 h), and rat, 69 +/- 9% (t1/2 = 12 h), and aminocarb in monkey, 95 +/- 14% (t1/2 = 8 h), and rat, 63 +/- 6% (t1/2 = 15 h). These results suggest rapid dermal absorption of these pesticides in rats and monkeys and the use of these animal models for measuring dermal penetration is discussed.
Topics: Administration, Cutaneous; Animals; Carbamates; Fenitrothion; Insecticides; Macaca mulatta; Male; Phenylcarbamates; Rats; Skin Absorption; Time Factors
PubMed: 3806704
DOI: 10.1080/15287398709530973 -
Journal of Toxicology and Environmental... 1987The toxicity of three cephalosporin antibiotics to rabbit kidney cells in culture was compared to their known nephrotoxic potential in vivo (cephaloridine greater than...
The toxicity of three cephalosporin antibiotics to rabbit kidney cells in culture was compared to their known nephrotoxic potential in vivo (cephaloridine greater than cefazolin greater than cephalothin). While cephalothin is considered to be a relatively nonnephrotoxic cephalosporin when administered to many species including humans and rabbits, in several in vitro systems involving rabbit renal tissue, cephalothin was comparatively more toxic than anticipated based on in vivo data. Cephalothin is extensively desacetylated in rabbits to a less microbiologically active metabolite, desacetylcephalothin. When a microsomal S9 fraction from rabbit kidney was added to the in vitro assay in cultured rabbit renal cells, cephalothin was desacetylated and its toxicity to kidney cells was reduced. The addition of S9 in vitro provided a toxicity ranking of the cephalosporins that correlated with their known in vivo nephrotoxic potentials (cephaloridine greater than cefazolin greater than cephalothin). The in vitro detoxification of cephalothin by S9 was blocked by the coadministration of the esterase inhibitor, aminocarb. Desacetylcephalothin was relatively nontoxic to rabbit renal tissue in vitro. These results suggest that the desacetylation of cephalothin in vivo represents a previously unrecognized mechanism of detoxification of this cephalosporin antibiotic. Furthermore, this mechanism of detoxification may be applicable to other acetylated cephalosporins.
Topics: Acetylation; Animals; Carbamates; Cells, Cultured; Cephalothin; Inactivation, Metabolic; Kidney; Phenylcarbamates; Rabbits
PubMed: 3612832
DOI: 10.1080/15287398709531054 -
Ecotoxicology and Environmental Safety Oct 1986Young brown bullhead (Ictalurus nebulosus) were exposed to aminocarb (4-dimethylamino-3-methylphenyl N-methylcarbamate) at lethal and sublethal concentrations and the...
Young brown bullhead (Ictalurus nebulosus) were exposed to aminocarb (4-dimethylamino-3-methylphenyl N-methylcarbamate) at lethal and sublethal concentrations and the tissue distribution of total unspecified residues was examined. The concentration of residues in each tissue increased with the concentration of exposure. The liver and stomach/intestine accumulated the largest concentrations of residues of all the tissues studied except for the abdominal fat deposit, which could not be evaluated at all exposure concentrations. These two tissues also displayed a steady increase in the proportion of the total body burden of aminocarb residues during 4 days of exposure to 0.092 mg aminocarb/liter. The proportion of residues in the carcass at this level of exposure decreased steadily over this same period, but was more similar to that found during exposure at the two lethal concentrations (92.7 and 159.3 mg/liter) as opposed to that found at the intermediate, nonlethal exposure level of 41.1 mg/liter. For all tissues examined, the concentration of residues at the end of 4 days of exposure to 0.092 mg/liter was significantly lower than the peak concentration reached during the exposure period, and clearance of residues was found to be relatively rapid.
Topics: Animals; Carbamates; Catfishes; Ictaluridae; Insecticides; Pesticide Residues; Phenylcarbamates; Tissue Distribution
PubMed: 3792270
DOI: 10.1016/0147-6513(86)90055-2 -
Archives of Environmental Contamination... Jul 1986
Topics: Animals; Biotransformation; Carbamates; Cattle; Cholinesterase Inhibitors; In Vitro Techniques; Insecta; Insecticides; Phenylcarbamates
PubMed: 3740948
DOI: 10.1007/BF01066405 -
Bulletin of Environmental Contamination... Apr 1986
Topics: Carbamates; Fenitrothion; Insecticides; Pesticide Residues; Phenylcarbamates; Plants; Quebec; Water Pollutants; Water Pollutants, Chemical
PubMed: 3697537
DOI: 10.1007/BF01623560 -
Toxicology and Applied Pharmacology Feb 1986The subchronic toxicity of a new formulation of Matacil (aminocarb) was assessed by exposing male and female Sprague-Dawley rats via a nose-only technique to a...
The subchronic toxicity of a new formulation of Matacil (aminocarb) was assessed by exposing male and female Sprague-Dawley rats via a nose-only technique to a respirable (2.0- to 4.1-microns diameter) aerosol at chamber concentrations of 22.5, 45, and 90 micrograms of insecticide/liter of air for 2 hr/day for 30 consecutive days. Control groups were exposed to a vehicle aerosol or to room air. Randomly selected rats of each group were bled after 8, 15, and 30 days of treatment, and after a 30-day recovery period. Routine clinical laboratory investigations (hematology, blood chemistry, and urinalysis) were conducted during treatment. Other parameters measured included body weight, feed intake, plasma, red blood cell count, brain cholinesterase activity, and hepatic and renal carboxylesterase activities. Organ weights were recorded at necropsy and routine histopathological evaluation was performed. Mild muscle tremors were observed occasionally in the intermediate- and high-dose groups. Treated females, but not males, demonstrated a dose-dependent inhibition of cholinesterase activity, though within treatment groups, there were no differences associated with the number of days of treatment. Enzyme values had returned to baseline levels by 30 days post-treatment. Hepatic carboxylesterase activity was significantly reduced only in male rats at the highest dose. Lung weights were increased in vehicle and Matacil-treated groups. Histological studies indicated that these changes were a nonspecific tissue response to a heavy burden of an oil-based irritant, which was partially resolved by 30 days post-treatment. The results showed that, at the concentrations tested, the formulation produced little or no acute symptoms and minimal long-term sequellae.
Topics: Acetylcholinesterase; Aerosols; Animals; Body Weight; Brain; Butyrylcholinesterase; Carbamates; Carboxylesterase; Carboxylic Ester Hydrolases; Erythrocytes; Female; Kidney; Liver; Lung; Male; Organ Size; Phenylcarbamates; Rats; Rats, Inbred Strains; Sex Factors; Time Factors; Triglycerides
PubMed: 3945947
DOI: 10.1016/0041-008x(86)90193-6