ISSN:0098-4108    

DOI:10.1080/15287399409531861

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two isolated rural communities of Mexico were studied to assess the possible relationship between lead‐glazed ceramics use and lead exposure. Women from these communities (n = 98) were asked to participate by filling out a general‐purpose and exposure questionnaire in order to assess the individual contribution of ceramics to lead exposure. Blood samples were withdrawn to measure lead in blood and erythrocytic zinc protoporphyrin levels. Results were analyzed by multiple regression in order to find predictors of the dependent variables. Significant association between lead in blood and erythrocytic zinc protoporphyrin levels was identified with the following variables: storage in lead‐glazed ceramics, cooking in lead‐glazed ceramics, and meat and cheese consumption. The adjusted regression models explained 20–23% of the variance of the dependent variables (lead in blood and erythrocytic zinc protoporphyrin). A significant association (r2= .38) was observed between lead in blood and lead in food prepared in lead‐glazed ceramics in a sub‐sample of 28 women. Results indicate that lead‐glazed ceramics use may be the main predictor of lead in blood and erythrocytic zinc protoporphyrin levels in the rural communities studied.

ISSN:0098-4108    

DOI:10.1080/15287399409531862

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

During the conduct of a long‐term toxicity/reproduction study using rhesus monkeys (Macaca mulatta), periodic hematologic and serum biochemical analyses were undertaken on blood obtained from 15 untreated (vehicle control) adult female monkeys over a period of 3 yr, 20 untreated adult males over a period of 6 yr, and 9 infants (5 mate, 4 female, whose dams were the vehicle control females) from 12 wk through 2 yr of age. All samples were obtained by femoral puncture. To facilitate handling, ketamine hydrochloride (Ket• HCI) was administered to the males, and for some of the later infant samplings. Complete blood cell counts were performed using electronic cell counters, while reticulocyte counts and leukocyte differentials were assessed manually. The serum biochemistry analyses were performed with automated analyzers. These data were obtained as part of a health monitoring program, with medians and 2.5 to 97.5 percentiles for each parameter indicated. Some monitored parameters were found to be affected by the type of equipment used and by the use of Ket•HCl.

ISSN:0098-4108    

DOI:10.1080/15287399409531863

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Twenty‐five microliters of a 2% saline solution of levofloxacin (LVFX) or ciprofloxacin (CPFX) was injected every other day for 2 wk into the knee joint space of CD rats (weighing 62.7–86.7 g) from the age of 3 wk. Early in the course of injection, histologic examination revealed chondrocyte necrosis without marked matrix change in the articular cartilage of the femoral condyles adjacent to the intercondylar groove. After 7 injections, the surface and intermediate zones of the articular cartilage showed extensive necrosis, sometimes with cavity formation in the center of the same portion. Papain completely depleted matrix basophilia in all zones throughout the condyle and caused cartilage necrosis with cavity formation. One injection of iodoacetic acid caused necrosis of almost all chondrocytes over the entire condyle, but chondrocytes sometimes remained alive in the portion where cavity formation was induced by quinolones. Chondroitinase depleted the matrix basophilia, and sometimes produced necrotic areas. DNA synthesis inhibitorsn‐ethyl‐maleimide, CPT‐11, and etoposide (VP‐16) caused chondrocyte necrosis, but never caused cavities in the articular cartilage. The DNA synthesis inhibitorsn‐ethylmaleimide, CPT‐11, and hydroxyurea were administered concurrently with po LVFX administration and significantly increased the incidence of LVFX‐induced cavity formation.n‐Ethylmaleimide was the most effective of all the inhibitors. The quinolone‐induced cavity formation is suggested to be site specific in the articular cartilage of rat femoral condyles. The depletion of matrix proteoglycans and chondrocyte necrosis may be necessary, although insufficient, to produce such lesions. Disruption of the collagen framework is suspected to contribute to their development. Involvement of altered DNA metabolism may play a role in the chondrocyte necrosis that occurs early in the specific sites.

ISSN:0098-4108    

DOI:10.1080/15287399409531864

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The toxic potential of manufactured gas plant residue (MGP) given in the diet to male and female B6C3F1 mice was evaluated. In addition, the bioavailability of chemical components of MGP were also investigated by monitoring polycylic aromatic hydrocarbon (PAH) metabolites in urine and DNA adduct formation in forestomach and lung tissue. Basal gel diets containing 0.05, 0.25, 0.50% MCP or 0.005% benzo[a]pyrene (BaP) were fed to animals for 94 and 185 d. Mice readily consumed adulterated diets without any evidence of acute toxicity. The total amount of MGP and BaP consumed by mice ranged from 118 to 2604 mg and from 12 to 29 mg, respectively. Male mice fed a control or BaP diet and female mice fed a 0.05% MCP diet had the highest body weight gains. Male and female mice fed a 0.50% MCP diet had the lowest body weight gains. The bioavailability of chemical components of MCP was evaluated by monitoring the urinary excretion of PAH metabolites by male mice fed a 0.25% MCP diet. 1‐Hydroxypyrene was determined by high‐performance liquid chromatography analysis to be the major fluorescent metabolite excreted by mice throughout the 185 d of diet administration. At necropsy, no chemical‐related gross lesions were detected. In addition, no treatment‐related microscopic lesions were evident in tissues obtained from animals fed a 0.50% MCP‐ or BaP‐adulterated diet. The32P‐postlabeling assay was used to evaluate MCP‐ and BaP‐induced DNA adduct formation in lung and forestomach tissue. The level of DNA adducts formed from the chemical components of MCP paralleled the amount of material ingested by animals. Lung DNA1 adduct levels were considerably higher than forestomach levels when mice ingested a 0.25% or 0.50% MCP diet. These studies demonstrate that the continuous ingestion of MCP or BaP for 185 d does not result in acute toxicity or chemical‐related lesions at doses up to 0.50% MCP or 0.005% BaP.

ISSN:0098-4108    

DOI:10.1080/15287399409531865

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A review of fluoride toxicity showed decreased fertility in most animal species studied. The current study was to see whether fluoride would also affect human birth rates. A U.S. database of drinking water systems was used to identify index counties with water systems reporting fluoride levels of at least 3 ppm. These and adjacent counties were grouped in 30 regions spread over 9 states. For each county, two conceptionally different exposure measures were defined, and the annual total fertility rate (TFR) for women in the age range 10–49 yr was calculated for the period 1970–1988. For each region separately, the annual TFR was regressed on the fluoride measure and sociodemographic covariables. Most regions showed an association of decreasing TFR with increasing fluoride levels. Meta‐ana/ysis of the region‐specific results confirmed that the combined result was a negative TFR/fluoride association with a consensus combined p value of .0002‐.0004, depending on the analytical scenario. There is no evidence that this outcome resulted from selection bias, inaccurate data, or improper analytical methods. However, the study is one that used population means rather than data on individual women. Whether or not the fluoride effect on the fertility rate found at the county level also applies to individual women remains to be investigated.

ISSN:0098-4108    

DOI:10.1080/15287399409531866

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0098-4108    

DOI:10.1080/15287399409531860

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor