Journal of Toxicology and Environmental Health, Part A最新文献

{"title":"Determination of blood‐lead elimination patterns of primary lead smelter workers","authors":"Han K. Kang, P. Infante, J. Carra","doi":"10.1080/15287398309530335","DOIUrl":"https://doi.org/10.1080/15287398309530335","url":null,"abstract":"Data for peripheral blood‐lead (PbB) levels for workers of four primary lead smelters in the United States were analyzed to characterize the patterns of PbB elimination. These workers had been removed from their job under the Medical Removal Protection (MRP) provision of the lead standard promulgated in 1978 by the Occupational Safety and Health Administration (OSHA). For each individual removed under the first or second year of the MRP provision, data for blood‐lead levels in relation to length of time removed were applied to four separate mathematical models, namely, linear regression, power curve fit, exponential curve fit, and logarithmic curve fit. The best model was determined by comparing overall correlation coefficients squared (r2) values derived from each model. Separate analyses were also made to test the relationship of PbB elimination rates to PbB levels at the time of the removal, length of occupational lead exposure, and job category. In addition, the duration of the medical removal time un...","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"40 1","pages":"199-210"},"PeriodicalIF":0.0,"publicationDate":"1983-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87352777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro evaluation of the tumor‐promoting potential of diesel‐exhaust‐particle extracts","authors":"P. Zamora, R. E. Gregory, A. Brooks","doi":"10.1080/15287398309530334","DOIUrl":"https://doi.org/10.1080/15287398309530334","url":null,"abstract":"Diesel‐exhaust‐particle extracts at nontoxic doses were evaluated in BALB/c mouse embryo 3T3 cells and Chinese hamster V‐79 lung cells for their ability to mimic the actions of the known tumor promoter tetradecanoyl phorbol acetate (TPA). The extracts were tested in a two‐stage model of carcinogenesis in 3T3 cells and found to marginally promote the occurrence of transformed foci over a concentration range of 2–10 μg/ml. The particle extracts also caused a loss of cell‐surface fibronectin and produced an increased saturation density of 3T3 cells. Using V‐79 cells, the extracts were found to inhibit metabolic cooperation between cells. Based on these results, it was concluded that diesel‐exhaust particles contain compounds that act as weak tumor promoters.","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"50 1","pages":"187-197"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90530488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modification of skin-graft rejection and acceptance by low concentrations of cadmium in drinking water of mice.","authors":"N. Balter, M. E. Kaweki, B. Gingold, I. Gray","doi":"10.1016/0192-0561(82)90282-X","DOIUrl":"https://doi.org/10.1016/0192-0561(82)90282-X","url":null,"abstract":"","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"35 1","pages":"433-9"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91150867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Panel discussion: Extrapolation from animal experiments to humans","authors":"P. Bogovski, L. Fishbein, B. Holmberg, P. Infante, R. Montesano, C. Ramel, U. Saffiotti, Marja Sorsa Moderator","doi":"10.1080/15287398009529951","DOIUrl":"https://doi.org/10.1080/15287398009529951","url":null,"abstract":"","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"24 1","pages":"1327-1335"},"PeriodicalIF":0.0,"publicationDate":"1980-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72765630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrastructure of hepatocellular tumors.","authors":"Z. Hruban","doi":"10.1080/15287397909529757","DOIUrl":"https://doi.org/10.1080/15287397909529757","url":null,"abstract":"The lesions that appear during hepatocarcinogenesis can be separated into morphologically distinct entities, which have been arranged into sequences believed to represent stages in carcinogenesis. Similarly, the primary and transplantable hepato-cellular carcinomas (HCC) can be arranged into a sequence of stages believed to represent the progression toward the ultimate cancer cell. Separation of morphological entities has been most successful in rat liver. Ultrastructural studies differentiate between lesions derived from hepatocytes and those originating in other cellular components of the liver. They show that there is variability and divergence in the structure of cellular organelles in the early stages of carcinogenesis, that there is simplification of cellular structure and of organelles during the progression of HCC, and that qualitative changes specific for cancer cells do not exist. Toxic changes associated with the process of carcinogenesis are loss of stacks; wrapping of cisternae around mitochondria; dilation, denudation, and vesiculation of cisternae; increase of autophagy; depletion of glycogen, and enlargement of nuclei and nucleoli. Early changes are storage of glycogen and hyperplasia of smooth endoplasmic reticulum. Subsequent alterations are increased variability in the size, shape, and structure of mitochondria and in the structure of endoplasmic reticulum, including the appearance of fingerprints. A transient stage recognizable by storage of lipid may represent a degenerative process. Ultrastructural characteristics of basophilic cells such as abundance of free ribosomes and absence of glycogen and of smooth endoplasmic reticulum suggest that they may be a stage in the formation of HCC. Progression of HCC is associated with a decrease in the number and size of mitochondria, reduction of mitochondrial cristae, decrease in the number and complexity of microbodies, reduction of the tubulovesicular form of smooth reticulum, accumulation of free ribosomes, and increase of the granular component and condensation of the fibrillar component of nucleoli. Various types of nuclear inclusions reflect the increased mitotic rate of the neoplastic tissue. Changes of the cellular surface are believed to be associated with the ability of the cells to invade and metastasize. Future investigations will require the use of single doses of potent carcinogens, application of morphometric methods at the ultrastructural level, and acceptance of primates as models for human hepatocarcinogenesis.","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"9 1","pages":"403-33"},"PeriodicalIF":0.0,"publicationDate":"1979-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78468375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental chemical carcinogens and liver cancer.","authors":"C. Linsell","doi":"10.1080/15287397909529742","DOIUrl":"https://doi.org/10.1080/15287397909529742","url":null,"abstract":"An appraisal is made of these chemical carcinogens available in the human environment that have been implicated in the etiology of liver cancer. The possible role of mycotoxins is discussed in detail, in particular the association between the aflatoxins and liver cancer in Africa and the Far East.","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"5 1","pages":"173-81"},"PeriodicalIF":0.0,"publicationDate":"1979-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81316742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Report of the workshop on mutagenicity.","authors":"T. Roderick","doi":"10.1080/15287397909529736","DOIUrl":"https://doi.org/10.1080/15287397909529736","url":null,"abstract":"","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"126 1","pages":"163-165"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77640369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Report of the workshop on carcinogenicity","authors":"W. H. Butler","doi":"10.1080/15287397909529735","DOIUrl":"https://doi.org/10.1080/15287397909529735","url":null,"abstract":"","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"37 1","pages":"161-162"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84832292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Halothane in tissue of rats following repeated subanesthetic exposures.","authors":"M. Wolff","doi":"10.1097/00132586-197806000-00016","DOIUrl":"https://doi.org/10.1097/00132586-197806000-00016","url":null,"abstract":"Halothane in tissues of the rat has been measured as a function of time after five successive 3 hr exposures to 670 ppm halothane. In epididymal and perirenal fat, halothane concentrations diminished rapidly from 310 ppm to 1-2 ppm in 24 hr, with trace amounts detectable 5 days later. Brain and liver levels were reduced from 16 and 9 ppm to less than 1 ppm within 3 hr. Blood halothane was reduced from 3 ppm to less than 0.5 ppm in the same time.","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"71 1","pages":"1079-83"},"PeriodicalIF":0.0,"publicationDate":"1978-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76076624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Covalent binding and endogenous incorporation as illustrated by nitroso carcinogens.","authors":"Magee Pn","doi":"10.1080/15287397709529486","DOIUrl":"https://doi.org/10.1080/15287397709529486","url":null,"abstract":"Serious problems of interpretation may arise when metabolic studies are carried out with radioactively labeled drugs and other foreign chemicals. Detection of free or bound radioactivity in tissues or body fluids may indicate the presence of the unchanged chemical or of various products of its decomposition. Some radioactivity may, however, represent incorporation of certain metabolites of foreign chemicals into body constituents by normal biosynthetic pathways. The interpretation of the results of such metabolic experiments from the standpoint of safety evaluation will be profoundly different if the radioactivity represents covalent binding to a cellular macromolecule than if it results from normal endogenous incorporation. These two distinct types of binding of radioactivity to body constituents are well illustrated by experimental studies with some carcinogenic nitroso compounds, such as dimethylnitrosamine and N-methylnitrosourea. Dimethylnitrosamine requires metabolic activation by microsomal enzymes and yields formaldehyde and a chemically reactive methylating intermediate, probably a methyl carbonium ion. The latter reacts with nucleophilic sites in nucleic acids and proteins, and also with water to yield methanol. N-Methylnitrosourea does not require metabolic activation but yields the same methylating intermediate spontaneously under physiologic conditions. Both formaldehyde and methanol are metabolized largely to CO2, but they also enter the one-carbon metabolic pool and became biosynthetically incorporated into nucleic acids, proteins, and other cell components. Alkylation of cellular constituents is associated with various biological effects, including cytotoxicity, carcinogensis, and mutagenesis, and the same effects are produced by the activated forms of a variety of other chemical carcinogens. It is clearly of paramount importance to distinguish between these two types of incorporation of radioactivity.","PeriodicalId":17418,"journal":{"name":"Journal of Toxicology and Environmental Health, Part A","volume":"95 1","pages":"882-93"},"PeriodicalIF":0.0,"publicationDate":"1977-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73432012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}