摘要:

AbstractThe approximiate lethal dose (ALD) to rats following oral administration of nine chemicals was determined. The ALD (lowest dose at which death was produced) for each chemical was used to define the general order of toxicity as being either extremely, highly, moderately, slightly, or practically non‐toxic. For each of the nine chemicals tested, the category indicated by the ALD was identical with the category determined in the more extensive LD50studies. In this study, an average of 6.8 rats was needed to determine the ALD while an average of 56.3 rats was needed to determine the LD5

ISSN:0260-437X    

DOI:10.1002/jat.2550060302

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractMercury (Hg) and selenium (Se) levels were determined for erythrocytes, plasma and urine of 25 male and 29 female workers exposed to elemental mercury (Hg0) vapor. Interrelationship between the Hg levels and the Se levels was examined by the correlational analysis and the stepwise regression analysis.Indicators of Se status (erthrocyte Se levels, plasma Se levels and urinary Se levels) were closely inter‐correlated; similary, indicators of exposure to Hg0vapor (erythrocyte inorganic Hg levels, plasma Hg levels and urinary Hg levels) were significantly intercorrelated. Since plasma Hg level was one of the significant independent variables in determining the erythrocyte Se and plasma Se levels, Hg0vapor exposure was though likely to influence the Se metabolism in workers. None of the Se status indicators were significant as determinants of the indicators of Hg0vapor exposur

ISSN:0260-437X    

DOI:10.1002/jat.2550060303

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractExperiments were performed to evalute reproductive and developmental toxicology in rats and rabbits exposed to styrene oxide by inhalation. Female rats were exposed to 100 or 300 ppm styrene oxide or to filtered air for 7 h/day, 5 days/week for 3 weeks. Extensive mortality occurred in rats that received prolonged exposure to 100 ppm styrene oxide while 300 ppm was rapidly lethal. As a result exposures were terminated in this latter group and the group was eliminated from further study. The rats of the 0 and 100 ppm groups were then mated and exposed to 0 or 100 ppm styrene oxide daily through 18 days of gestation (dg).Female rabbits were artificially inseminated and exposed for 7 h daily to 0, 15, or 50 ppm styrene oxide through 24 dg. Both of these lower concentrations used for exposure of the rabbits produced mortality of does. The rats were killed at 20 dg and the rabbits at 30 dg. Pregnant animals were examined for toxic changes including altered tissue weights and histopathologic effects. Litters were evaluated using several measures of embryotoxicity, and live fetuses were examined for external, visceral, and skeletal malformations.Exposure during gestatation appeared to increase preimplantation loss in rats, and tended to increase the incidence of resorptions in rabbits. In both species, fetal weights and crown‐rump lengths were reduced by gestational exposure. The incidences of ossification defects of the sternebrae aned occipital bones were increased by gestational exposure of rats to styrene oxide. These results indicate that inhalation exposures at these concentrations produce reproductive and development toxicity, as well as maternal toxicit

ISSN:0260-437X    

DOI:10.1002/jat.2550060304

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe Chernoff and Kavlockin vivoassay was used to study the teratogenic potential of ethylene glycol monomethyl ether (EGME). It was administered to pregnant rats on days 6–17 (inclusive) of gestation by the dermal route at an application rate of 10 ml kg−1body weight of 3%, 10%, 30% and 100% EGME with physiological saline as the solvent. 100% was lethal to the pregnant rats, 30% was lethal to the fetuses, 10% produced small litter sizes with poor survival and 3% had no adverse effects. By the ‘rules’ developed to evaluate results from the assay, 10% was judged to be a potentially teratogenic dose in the rats. The study also demonstrated the usefulness of this assay for pre‐screening or additional investigations for suspected teratogens when route of exposure could be important in determining the potenti

ISSN:0260-437X    

DOI:10.1002/jat.2550060305

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractExposure of hamster embryo cells (HEC) to mixtures of benzo(a) pyrene and soluble Ni2+neutral salts elicits additive responses in the enhanced nucleoside excretion assay. Ni2+shows no significant excretion response until concentrations near 10 μM are reached. Addition of 0.4 micromolar benzo(a)pyrene and 30 μM, or 325 μM Ni2+to HEC cultures results in total excretion equal to the sum of excretions induced by the individual chemicals. These observations suggest that excretion of pyrimidines may be a useful measure of biological dosimet

ISSN:0260-437X    

DOI:10.1002/jat.2550060306

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractAn epidemiologic investigation was carried out to clarify the significance of the urinary excretion of α1‐microglobulin (α1‐MG) in people aged 50 years and over living in a Cd‐polluted area in Japan. Approximately 80% of the population participated in the health examination. The urinary and serum levels and the relative clearance of α1‐MG to creatinine clearance were compared with various parameters (age, urinary β2‐microglobulin (β2‐MG), total protein, Cd, Cu and Zn, serum β2‐MG, creatinine and blood urea nitrogen and relative clearances of α1‐MG, β2‐MG, inorganic phosphate and uric acid). It was found that the urinary excretion of α1‐MG is closely associated with the urinary Cd and Cu and with the indices of renal dysfunction listed above. These results suggest that the urinary α1‐MG level masrkedly reflects a degree of proximal tubular dysfunction and that it may be useful as one of the screening measures for proximal tubular dysfuction caus

ISSN:0260-437X    

DOI:10.1002/jat.2550060307

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA two‐generation female reproduction and teratology study was undertaken using 0, 1.5 and 3.0 ppm of T‐2 toxin in a semisynthetic diet. Conception rate was lowest at the first breeding and lowest in the control group at this time, but in later breedings the conception rates of each group were very similar. No significant differences were noted in litter size, death of fetuses, sex of fetuses and gestational length. Feed consumption was similar in all groups, as were the non‐pregnant or pregnant female weight gains. Although the second‐generation offspring grew faster than the first‐generation offspring, and significantly lower body weights were seen in the 3.0 ppm T‐2 toxin group at 2, 5 and 6 weeks of age, all offspring reached the normal weight for CD‐1 mice at 6 weeks of age. Gross and histological evaluation of all animals at postmortem examination did not reveal any significant results, nor were there significant differences in major and minor or retardation defects among the treatment groups. Relative spleen weights of the second‐generation offspring were significantly higher in control females compared with the treated groups but treated males had significantly increased relative spleen weights compared with control males of this generation. It was concluded that no long‐term reproductive and teratological effects of low‐dose dietary T‐2 toxin wer

ISSN:0260-437X    

DOI:10.1002/jat.2550060308

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractRat β2‐microglobulin has been isolated from the urine of rats pretreated with sodium chromate. The purified protein was used to raise antisera in two rabbits. Treatment of the antisera with ammonium sulphate followed by gel chromatography led to an immunoglobulin fraction which was used to coat latex particles by physical adsorption. The latex suspension was used in an automated system including an optical particle counter to analyse the protein in serum, urine and cerebrospinal fluid. Serum contains 5.8 mg of β2‐microglobulin/l, of which 33% is found as a 55000 dalton complex while 66% is present as the ‘free’ protein. The daily urinary excretion of β2‐microglobulin in females is about 2 μg of which 7% is found to be a 65000‐dalton complex while 92% is the free protein. From this, it can be calculated that the fractional urinary excretion of β2‐microglobulin is about 0.03%. The cerebrospinal fluid contains about 1 mg of β2‐microglobulin/l. Preliminary tests also suggest that the method can be adapted for non‐automated turbidimetric detection. In the automated assay, the within‐ and between‐assay coefficients of variation are less than 10% for the three biological fluids tested. The analytical recovery in the urine is 93%. In urine, β2‐microglobulin undergoes proteolytic degradation at pH below 6. This does not represent a serious drawback to its use as a sensitive index of tubular function since in most experimental circumstances, rats excrete ur

ISSN:0260-437X    

DOI:10.1002/jat.2550060309

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

Abstractβ2‐microglobulin (β2‐m) was measured in the urine of rats by a specific immunoassay based on latex particles agglutination. the excretion of this protein was compared to the excretion of the enzyme β‐N‐acetyl‐D‐glucosaminidase (NAG), albumin and amino acids in rats treated with either a single dose of sodium chromate (5 and 10 mg kg−1), repeated doses of gentamicin (5 and 20 mg kg−1), or cadmium (1 mg kg−1), and in aging rats (from 2 to 20 months). All treatments resulted in an early increased excretion of β2‐m indicative of functional alterations of the proximal tubular cells. An increased NAG excretion was observed only at the highest dose of chromate and in the cadmium model but the relative increases of β2‐m were much larger (up to 200 times the control values against four times the control values for NAG). From 2 to 20 months of age, urinary β2‐m increases by a factor of four. Aminoacids excretion showed little sensitivity in the various models. Albumin showed little variations in purely tubular or in the tubular phase of renal injury but the chronic progressive nephrosis of aging rats caused a 40‐fold increase in its excretion between 2 and 20 months of age. Therefore urinary β2‐m, albumin and albumin/β2‐m ratio provide useful tools in the assessment of nephrotoxicity and of its mech

ISSN:0260-437X    

DOI:10.1002/jat.2550060310

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractBronchopulmonary lavage has been used as a rapid screening test for acute lung injury from many pneumotoxic chemicals. We demonstrated the efficacy of lavage fluid analysis for detection of acute pulmonary damage from inhaled metal dusts. Groups of male, Fischer 344 rats were exposed 4 h to one of five dosage levels of either brass (200, 100, 50, 10, 1 mg m−3) or aluminum (1000, 200, 100, 50, 10 mg m−3). At 24 h, 14 days and 3 months post‐exposure (PE), rats were evaluated for physiological and histological alterations to correlate with enzymatic and cytological profiles of lavage fluid. At 24 h PE, there were dose‐related increases in lactate dehydrogenase and protein in lavage fluid of the brass exposed rats, acute inflammatory response in terminal airways, increases in macrophages and neutrophils, and increased pulmonary resistance. All reactions were resolved by 14 days PE. In contrast, alumium powder produced no alteration in pulmonary function, but elicited persistent changes in enzymatic and cytological lavage fluid parameters with multifocal microgranlomas in lungs and hilar lymph nodes. Bronchopulmonary lavage analysis was useful as an indicator of inhalation hazards of brass and aluminum

ISSN:0260-437X    

DOI:10.1002/jat.2550060311

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY