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At least 37 records · Page 2Linked to original sources
PubMed1978

Recurrent hepatitis following halothane exposures.

The existence of hepatotoxicity due to halothane remains subject to debate. Three cases are presented in which multiple exposures to halothane were followed in several instances by evidence of postoperative fever and/or hepatitis. In one case, hepatitis with bridging necrosis developed; the patient responded to long-term steroid therapy. In another, fulminant hepatic necrosis proved fatal. A brief review of halothane hepatitis is given. Otherwise unexplained fever and hepatitis following the use of halothane, especially if recurrent or accompanied by evidence of hypersensitivity, should contraindicate subsequent use of that drug.

Biopsy↗
PubMed1978

Jaundice after repeated exposure to halothane: a further analysis of reports to the Committee on Safety of Medicines.

Aanalysis of data derived from 170 reports of jaundice developing after anaesthesia with halothane received after January 1974 confirmed the relations between multiple exposure to halothane and jaundice and between the number of exposures and the rapidity with which jaundice develops after exposure. When these reports were combined with 130 received earlier complete anaesthetic histories were available for 251 patients, 205 (82%) of whom had been exposed to halothane more than once; of these patients, 154 (75%) had been exposed more than once within 28 days. Altogether 139 (46%) of the 300 patients died.

Anesthesia, Inhalation↗
PubMed1977

Influence of aliphatic alcohols on the hepatic response to halogenated olefins.

The role of alcohols in potentiating the toxicity of halogenated hydrocarbon solvents has been reviewed. The toxicity of carbon tetrachloride and chloroform can be markedly potentiated by prior treatment with ethanol or phenobarbital. Trichloroethylene toxicity may also be potentiated by ethanol ingestion. Prior ethanol ingestion acts by altering biochemical parameters that result in an increased response to subsequent solvent exposure. Simultaneous exposure to both ethanol and trichloroethylene allows for competitive substrate inhibition of metabolism since these compounds share several common enzymatic pathways. Thus the toxic response to multiple exposures varies depending upon the time sequence and the comparative levels of the individual components. Phenobarbital apparently potentiates solvent toxocity by induction of the microsomal mixed function oxidase system. Ethanol, either on a chronic or single dose basis, also has the ability to stimulate this enzyme system. Although alteration of the microsomal mixed function oxidase system by chronic ethanol ingestion may play an important role in potentiation of solvent toxicity, the potentiation seen following a single dose of ethanol cannot be fully accounted for by the known effects of ethanol on the mixed function oxidase system. In addition to ethanol a large number of other alcohols will markedly potentiate the hepatotoxic response to solvents such as carbon tetrachloride and chloroform. The mechanisms involved in such potentiation are not known at the present time.

Alcohols↗
PubMed1978

Discoloration of permanent front teeth in 3,157 Norwegian children due to tetracyclines and other factors.

During routine orthodontic screening in Oslo, Norway, of 3,157 children, aged 1--11 years and born in 1963/64, 36 cases (1.14%) with cosmetically marring discoloration of permanent front teeth were registered. Thirty-four of them arrived for a more exhaustive examination, which in 24 of the children revealed positive tetracycline fluorescence on exposure to ultraviolet light. In 13 (0.4%) of the children, the discolorations were diagnosed to be tetracycline-induced. Enamel hypoplasia was frequently found in teeth with positive fluorescence. Multiple exposures to various tetracyclines were reported in all children who exhibited positive fluorescence.

Child↗
PubMed1979

Exposure to chemicals, physical agents, and biologic agents in mycosis fungoides and the Sézary syndrome.

The history of occupational, environmental, and/or iatrogenic exposure to potential carcinogenic agents was obtained at the time of onset of skin disease in 43 of 44 patients with cutaneous T-cell lymphoma (mycosis fungoides and the Sézary syndrome) entering a National Cancer Institute therapeutic trial. A history of multiple exposures to these agents was common, the two most frequent being chemicals (91% of patients) and drugs (86%). Mean duration of expsosure was 13 years for chemicals and 18 years for drugs. The most common chemicals were air pollutants (39%), pesticides (36%), solvents and vapors (30%), and detergents and disinfectants (14%). Increased severity of disease was seen with increaed duration of chemical exposure in stage V cutaneous T-cell lymphomas only. The most frequent drugs besides tobacco (86%) were analgesics (20%), tranquilizers (18%), and thiazides (14%). Second cancers occurred in four patients, including two renal cell carcinomas, and a family history of cancer was present in 11. Fourteen of 22 patients questioned had recurrent herpes simplex. Patients with chronic skin disease who have long-term exposure to combinations of chemicals, physical agents, and biologic agents, are heavy smokers, or have recurrent herpes simplex appear to be prime candidates for developing mycosis fungoides or the Sézary syndrome.

Adult↗
PubMed1977

Proliferative response of human diploid fibroblasts to intermittent light exposure.

Three- to four-hour exposure to fluorescent light, one to three times weekly, reproducibly enhanced the proliferation rate of human diploid fibroblasts. This enhancement was observed in WI-38 and a line from whole embryo mince at late population doubling level (PDL) as well as in a line from adult skin at early PDL. Single or multiple exposures of short duration stimulated proliferation, whereas exposures of long duration were cytotoxic. This proliferative response is reversible, and is mediated through the culture medium, Dulbecco Vogt's supplemented with 10% fetal bovine serum. Apparently light produces some mitogenic substance(s) in the culture medium that accumulates in the cells and is toxic or growth-stimulatory depending on its concentration per cell. Another possibility is that light produces in the medium both cytotoxic and growth-stimulatory substances.

Cell Division↗
PubMedDate not supplied

Synergism of methylmercury and selenium producing enhanced antibody formation in mice.

Mice fed 1, 5, and 10 ppm methylmercury plus 6 ppm selenium for 10 wk had a significant increase in antibody synthesis. Since methylmercury singly depresses antibody synthesis and the response was greater than that produced by selenium alone, synergism between methylmercury and selenium occurred. In this case, the synergism is considered to be advantageous to a host, while exposure by other combinations of environmental contaminants may be detrimental. Mercury concentrations in the kidney were markedly elevated when methylmercury and selenium were administered simultaneously compared to when methylmercury was given without selenium supplement. These results indicate that data collected from individual pollutants may not be of value in predicting responses to multiple exposure.

Animals↗
PubMed1976

An assessment of investigations conducted in the USA on Brucella abortus strain 45/20 bacterins.

The results of five investigations in cattle using 45/20 Bacterins are presented and evaluated. Seemingly contradictory results may be the result of one or more modifications in project design or in procedures. In these trials, there appeared to be no significant difference in the level of protection for cattle when using either intramuscular or subcutaneous routes of injection or when 10 or 12 week intervals between doses were used in cattle 6 months of age or older. Also, the relative resistance to subsequent exposure was not significantly different in which only 45/20 Bacterins were administered. There were apparent differences in protection between cattle receiving one versus two doses of 45/20 Bacterin or initially vaccinated with 45/20 Bacterin at 3 months of age and again 15 weeks later compared to older age groups vaccinated at 10 or 12 week intervals between doses. The disproportionate infection rate among 45/20 vaccinated animals in the last completed investigation suggests that cattle in infected herds subjected to multiple exposures to virulent organisms do not develop adequate resistance. Local and systemic reactions following the administration of 45/20 Bacterin were also noted in some groups.

Animals↗
PubMed1978

Ultraviolet light in the oncogenic transformation of cultured C3H/10T1/2 mouse embryo cells.

Skin tumors are produced in rats, mice, and humans by exposure to UV light. We developed a mouse embryo fibroblast line C3H/10T1/2, which can be transformed by chemical carcinogens, X-irradiation, UV radiation, and oncornavirus. When we irradiated these cells with 10, 25, 50, 100, 150, or 200 ergs/mm2 of UV light, neither transformation nor cytotoxicity was observed at the two lower doses. When the irradiated cells were cultured in medium containing 0.1 micrograms TPA/1 ml (a potent tumor promoter) starting from 0-120 hours after irradiation, a high frequency of transformation was always produced. When the cells were initiated with subeffective concentrations of 0.1 micrograms MCA/ml followed by UV radiation at different intervals, no transformation occurred; however, these initiated cells were transformed after TPA treatment. When we treated the cells with multiple exposures to UV light, no transformation occurred then nor when the cells were treated with TPA followed by UV irradiation at different intervals. Thus UV in our system acts as a pure initiator in the two-stage process of oncogenic transformation.

Animals↗
PubMed1976

Challenge of dogs with live enterotoxigenic Escherichia coli and effects of repeated challenges on fluid secretion in jejunal Thiry-Vella loops.

Dogs were evaluated as experimental models for the study of diarrheal disease produced by enterotoxigenic Escherichia coli. Although a suitable whole model for orogastric bacterial challenge could not be developed, chronic jejunal Thiry-Vella loops were used to study the secretory effects of multiple jejunal challenges with enterotoxin of either Vibrio cholerae or E. coli. The heat-stable and heat-labile E. coli enterotoxins could be differentiated clearly in this model. Sequential weekly challenges over a four-week period showed a significant decrease in loop secretory response to homologous enterotoxin, although levels of antitoxin in serum remained unchanged, a finding suggesting a local immune response. Dogs challenged with E. coli enterotoxin were markedly protected against subsequent challenge with V. cholerae enterotoxin; the converse was not true. Histologic studies of the loops showed only minimal atrophy, and results of absorption studies in the loops were normal. These studies suggest that mongrel dogs are resistant to colonization by enterotoxigenic E. coli and partially resistant to challenge with enterotoxin, perhaps on an immune basis due to prior antigenic exposure. Multiple challenges with enterotoxin effect a decreased secretory response; this finding also suggests a local immune mechanism.

Animals↗
PubMed1978

Halothane hepatitis.

Halothane (2-bromo-2-chloro-1:1:1-trifluoroethane) is a volatile, nonflammable anaesthetic agent which has been widely used for the last 20 years. Halothane hepatitis has been a matter of continuing controversy, but now it seems to be generally accepted as a clinical entity. Characteristically the halothane hepatitis occurs after multiple exposures to halothane within short time. The pathogenesis of the liver cell damage is obscure. It is estimated that the incidence of halothane hepatitis is about one per 8000 halothane anaesthesias and the lethality about one per 40000. Prophylaxis consists of avoiding repeated halothane anaesthesias within short time and to avoid re-exposure to halothane if otherwise unexplained liver damage has occurred after halothane.

Chemical and Drug Induced Liver Injury↗
PubMed1977

Frequency and pattern of radionuclide administration to medical patients in a general hospital.

As part of a drug surveillance programme details of nuclide administration were recorded for 5288 consecutive patients admitted to the medical wards of a large general hospital. Overall use of nuclides amongst this group was found to be low, and multiple exposure to radiation as a result of nuclide administration is not a major hazard when compared to the diagnostic information provided.

Hospitals, General↗
PubMed1979

Factors affecting sperm motility. I. In vitro change in motility with time after ejaculation.

Semen specimens from 33 donors were analyzed intermittently between 1 and 24 hours after ejaculation. Motility was determined objectively by analyzing still-camera photomicrographs taken with the aid of the new multiple exposure photography (MEP) technique, from which the following information was obtained: the percentage of motile spermatozoa, the average velocity and frequency distribution of spermatozoal velocities, and index of motility as well as sperm concentration. From curves drawn for each of the 33 analyzed specimens, these conclusions were drawn: 1. The percentage of motile spermatozoa decreases progressively, beginning 1 hour after ejaculation, at a rate of about 5% to 10%/hour. 2. In the majority of cases, sperm velocity increases for the first 4 hours and then decreases gradually. 3. There is no unique pattern of sperm motility and velocity with time for all specimens, especially during the first 4 hours. However, three typical curves of motility change were found during the first 4 hours: increase in motility, moderate decline in motility, and rapid loss of motility. 4. The frequency distribution of velocities of motile spermatozoa revealed typical normal curves at all times, but these curves became flatter as time elapsed. An explanation for these divergent patterns and the possible role of these findings in some physiologic and clinical problems are discussed.

Ejaculation↗
PubMed1979

Factors affecting sperm motility. II. Human sperm velocity and percentage of motility as influenced by semen dilution.

Spermatozoal velocity and percentage of motility were analyzed objectively with the multiple exposure photography method before and after specimens from fertile and infertile men were diluted in their own seminal plasma or normal saline. No significant change in percentage of motility was found in samples diluted up to 1:6 in both kinds of diluents. However, a significant relative increase (up to 25% of the original velocity) was found when a specimen was diluted with its own seminal plasma, and an even greater increase (up to 37% of the original velocity) was found when it was diluted with saline. Compared with undiluted specimens, there was no delayed effect on spermatozoal motility when semen was diluted with saline after up to 4 hours' incubation time. Contrary to the findings in animal and human semen described by others, there was no deleterious effect on sperm motility with this kind and rate of dilution and duration of time. The assumption that the increase in sperm velocity caused by dilution is not excitatory but is due only to a decrease of seminal fluid viscosity and a reduced number of spermatozoa which interfere with sperm free movement is discussed. We recommend evaluation of spermatozoal motility in diluted specimens in addition to evaluation of the original specimen in any routine semen analysis in order to determine true spermatozoal motility potential under optimal conditions.

Culture Media↗
PubMed1977

Heart rate and cardiac phase influences on visual perception.

Twenty-six subjects were tested with a tachistoscopic recognition task while heart rate and several other autonomic indexes were monitored. In Experiment 1, heart rate was employed as an independent variable, and stimulus presentation was contingent upon the presence of individually determined low, middle, and high heart rates. The results indicated that low heart rate facilitated performance especially for stimuli presented at the fastest exposure. In Experiment 2, stimulus presentation was dependent upon cardiac phase. The findings indicated that stimulus recognition was enhanced during the cardiac P wave, but the effect was apparent only during the fastest exposure. Multiple regression analyses of the individual subject's data during both experiments indicated that highly idiosyncratic patterns of physiological responses predicted perceptual performance. The results were interpreted as being consistent with the formulations of the Laceys and also suggested that cerebral perfusion be considered as a relevant determinant of behavior.

Adult↗
PubMed1975

Tumor induction by carcinogenic agents in aquarium fish.

The effects of nine carcinogens on 1,220 guppies [Poecilea reticulata (Lebistes reticulatus)] and 40 zebra fish (Danio rerio) were studied. Multiple exposure techniques included skin application, im and ip injections, feeding, implantation in pellets, and dissolving of the compound in the aquarium water. 7-12-Dimethylbenz[a]anthracene, 3-methylcholanthrene, and benzidine produced no tumors in the fish. N-2-Fluorenylacetamide, omicron-aminoazotoluene, 4-dimethylaminoazobenzene, diethylnitrosamine, and dimethylnitrosamine induced tumors in the livers of some of the fish. These neoplasms included cholangiomas, hepatoadenomas, cholangiocarcinomas, and hepatocellular cancers. Nitrosomorpholine caused not only hepatic tumors in guppies and zebra fish but also intestinal adenocarcinomas and poorly differentiated connective-tissue lesions in the abdominal cavities of zebra fish. Experimental induction of tumors in aquarium fish offers wide possibilities for comparative cancer research. Fish are a suitable model for the testing of compounds for carcinogenic activity and for the screening of environmental carcinogens.

2-Acetylaminofluorene↗
PubMed1978

Effect of reovirus infection on pulmonary tumor response to urethan in strain A mice.

The effect of reovirus type 3 infection on the pulmonary adenoma response to urethan in strain A mice was examined. Urethan carcinogenesis in this system was suppressed from 30 to 60% when mice were exposed to reovirus either 6 days before, on the same day as, or 14 days after urethan administration. These findings suggested that reovirus infection interfered with the progression of urethan-induced pulmonary adenoma rather than the induction of lung tumors by urethan. When mice received multiple exposures to reovirus, the lung tumor response was enhanced. These findings indicated that reovirus infection in particular and virus infection in general may play an important role in the carcinogenic response to environmental chemicals.

Adenoma↗
PubMed1977

Asymmetric waveforms in echinoderm sperm flagella.

1.Dark-field, multiple-exposure photographs of live spermatozoa of a number of echinoderms were analysed. 2. Bends develop at the base in pairs, as they do in flagella with symmetrical waveforms. However, the angles of these bends do not cancel, so that microtubular sliding-of up to over 50% of that associated with bend propagation-is transferred distally. This sliding implies that (a) microtubules are not rigidly cross-linked within straight regions, and (b) bends can propagate normally in spite of appreciable extrinsic microtubular sliding. 3. Both the sperm head and the asymmetry of the waveform appear to affect the swim path of a spermatozoon.

Animals↗