摘要:

AbstractA reversed‐phase HPLC method for determination of 25‐hydroxycholecalciferol (25‐OH D3) in serum samples is described. The method involves extraction of 25‐OH D3with hexane, followed by differential resolubilization in acetonitrile. The sample is then applied directly on the C18bonded phase column of the liquid chromatograph, and developed in a acetonitrile‐water solvent system. In the range 12.5–400 ng, a linear relationship was observed between detector response and the amount of 25‐OH D3placed on the column. Also, a very good correlation was observed between the amounts of 25‐OH D3added to serum samples, and the calculated amounts. The method can be used for screening for toxicological levels of 25‐OH D3in patients treated with high do

ISSN:0260-437X    

DOI:10.1002/jat.2550030602

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe body of information in this paper is directed to specialists in industrial health and safety, and air and water pollution, who need quantitative data on the odor thresholds of potentially hazardous chemical vapors and gases. The literature, largely unorganized, has been reviewed for 214 compounds and condensed into tables based on consistent units. Data on the volatility, solubility, ionization and water‐air distribution ratio at 25°C are included. From the currently recommended threshold limit value (TLV), a safe dilution factor and an odor safety factor are calculated for each compound. The equivalent data are presented for both air and water dilutions of the chemicals. Available data are summarized on the variability of odor sensitivities in the population, and the increased odor concentrations that are required to elicit responses from persons whose attention is distracted, or who are sleeping. This information is reduced to calibration charts that may be used to estimate the relative detectability, warning potential and rousing capacity of the odorous vapors. Each compound has been assigned a letter classification, from A to E, to indicate the margin of safety, if any, that may be afforded by the odor of the compound as a warning that its threshold limit value is being exceed

ISSN:0260-437X    

DOI:10.1002/jat.2550030603

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effect of a composite antidotal treatment — consisting of a mixture of calcium alginate, ferrihexacyanoferrate(II) and potassium iodide — administered in diet and/or Na3(CaDTPA) administered intraperitoneally on the absorption and the removal of radioactive strontium, caesium, iodine and cerium was investigated in 7‐week‐old female rats. The animals were on respective treatments for 3 days. The retention of141Ce,85Sr,137Cs and131I was determined in the whole body, carcass, gut, liver, kidneys and respective critical organs (femur, muscle, thyroid) 6 days after their oral or intraperitoneal administration. In animals which received the antidotal mixture or Na3(CaDTPA) alone, the radionuclide retention was practically the same as in rats which were given the composite treatment [mixture + Na3(CaDTPA)]. This indicates that the efficiency of one treatment was not increased by the other. For141Ce, Na3(CaDTPA) was an effective antidote, while85Sr,137Cs and131I were reduced by the mixture. It is concluded that the composite treatment might be a quick treatment for choice for reducing mixed fission products retention, especially in cases when identification of exposure is difficult or impossible

ISSN:0260-437X    

DOI:10.1002/jat.2550030604

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractLung burdens of deposited particles from fumes generated by arc‐welding were established in rats by single inhalation exposures, repeated intermittent exposure or by intratracheal injection. Fumes from manual metal arc‐welding using flux‐coated mild‐steel rods (MMA‐MS) were compared with those from metal inert‐gas welding with stainless steel wire (MIG‐SS). After initial rapid clearance of deposited material from the lungs, persistent residual deposits remained. Such residues resulting from single inhalation were small and confined mainly to peribronchial accumulations in macrophage clusters. Deposits remaining after repeated inhalation were larger and more widespread. Intratracheal administration (50 mg) established massive residual deposits, giving nodular accumulations in peribronchial, subpleural and perivascular sites, with substantial alveolar parenchymal involvement. Deposits from both types of fumes contained predominantly iron. Particles from stainless steel also contained chromium, but concentrations of this element were low in deposits from MMA‐MS fumes. MMA‐MS deposits contained silica, probably amorphous. Long‐term studies (up to 450 days) attempted to detect evidence of fibrosis resulting from particle burdens. Low‐grade collagen fibre layers developed at margins of MMA‐MS nodules. Diffuse reticulin fibre networks occurred within MIG‐SS aggregates. Tissue hydroxyproline levels were increased (doubled) in lungs with intratracheal burdens of MMA‐MS particles, but no significant increases resulted from MIG‐SS. The major lesions were nodular aggregates of particle‐laden macrophages with giant‐cell formation, and alveolar epith

ISSN:0260-437X    

DOI:10.1002/jat.2550030605

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe effect of chronic exposure to 100 ppm (0.01%) CO on pituitary‐adrenal activity was evaluated by measuring serum corticosterone and brain bioamine levels in the rat. Exposure to CO for 1 month induced a decrease in the brain serotonin levels. Serum corticosterone, brain dopamine and noradrenaline as well as the weight of the adrenal glands, lungs, spleen and liver were unchanged. After two months of exposure, serum corticosterone and brain serotonin levels were elevated and the liver weight was significantly lower. This suggests that at this chronic low concentration CO acts as a stressor, and the organism initiates a general defensive reaction. The effect of CO on the pituitary‐adrenal axis could be mediated by a central neuronal path

ISSN:0260-437X    

DOI:10.1002/jat.2550030606

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractBlood‐flow distribution was determined in pentobarbital‐anesthetized male B6C3F1 mice, using intracardially administered141Ce‐radiolabelled microspheres (10μm). The proportion of cardiac output and blood flow per g tissue was determined in 18 organs and tissues, including the nasal cavity, lobes of the liver, individual kidneys and sections of the intestinal tract. To provide comparative data, blood‐flow distribution was also determined in pentobarbital‐anaesthetized male Fischer 344 rats. In general, there was close agreement between the distribution of blood flow between these two rodent species. The bladder and large intestine of mice appear to receive more, while the testes receive less, of the cardiac output than in rats. Rat liver and kidney, however, appear to receive approximately twice the amount of blood on a weight basis as in

ISSN:0260-437X    

DOI:10.1002/jat.2550030607

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractRats were injected with 120 μCi of14C‐acetaldehyde containing carrier acetaldehyde, and the urinary excretion products were assayed by cation exchange chromatography, resolving five main peaks of radioactivity. Urine contained 6% of the dose of14C‐acetaldehyde administered. The main urinary product of acetaldehyde, fraction 5, was produced via acetate. Acetate was also identified in the urine. Two cysteine adducts, probably isomeric metabolites of 2‐methylthiazolidine‐4‐carboxylic acid, were detected. They constituted about 2% of the radioactivity in the urine collected 48 h after the administration of14C‐acetaldehyde. They appeared to retain a carboxylic group. When the reaction mixture of14C‐cysteine and acetaldehyde was injected into a rat, the half‐lives of the two tiazolidine derivatives was 10 h. Only 13.6% of the radioactivity was detected in the urine suggesting ready metabolism of 2‐methylthiazolidine

ISSN:0260-437X    

DOI:10.1002/jat.2550030608

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe genetic activity of the structurally similar antitumor antibiotics anthramycin, tomaymycin and sibiromycin was evaluated in the standard AmesSalmonella/microsome mutagenicity assay, aSalmonella typhimuriumforward‐mutation assay and the micronucleus test. None of the test drugs showed any significant genetic activity in forward or reverseSalmonellamutation assays. The ability of mouse‐liver enzymes to produce mutagens from the drugs was examined in theSalmonellareverse‐mutation assay and was generally negative. As the concentrations of sibiromycin increased, some activity was detected in the presence of liver S‐9 fractions from Aroclor‐induced mice. This observation could not be verified at higher concentrations in the reverse‐mutation assay due to cytotoxicity, and in the forward‐mutation assay due to interference with the selection process by S‐9. Cytogenetic evaluation of anthramycin and tomaymycin in the micronucleus test also gave negative results. However, significant increases in the frequency of micronucleated polychromatic erythrocytes were observed in the bone marrow of sibiromycin‐treated mice. The results suggest that, except for some possible activity of sibiromycin, these drugs are generally devoid of any marked genetic activity in the test

ISSN:0260-437X    

DOI:10.1002/jat.2550030609

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe nephrotoxinS‐(1,2‐dichlorovinyl)‐L‐cysteine (DCVC) is cleaved in the renal tubules to produce a reactive electrophilic intermediate. If this intermediate is responsible for the toxicity, addition of the nucleophilic scavenger glutathione (GSH) should decrease toxicity, and depletion of tubular GSH should enhance toxicity. GSH was added to isolated rabbit renal tubules simultaneously with, 15 min before, and 15 min after the addition of DCVC. The active accumulation of the organic anion para‐aminohippuric acid (PAH) and organic cation tetraethylammonium bromide (TEA) was used as an index of renal toxicity. Incubation of renal tubules with 0.01–1 mM DCVC for 15 min decreased active transport, with complete inhibition at 1 mM. This was accompanied by a 50% decrease in non‐protein sulfhydryl concentration. The addition of GSH (6 mM) simultaneously with DCVC completely prevented any decrease in active transport. The addition of GSH (6 mM) to tubules in which active transport was inhibited by DCVC reversed the inhibition to 80% of control. Similar enhancement of active transport occurred when tubules isolated 1 h afterin vivoexposure to DCVC at 20‐100 mg kg−1were incubated with GSH (6 mM). Preincubation of renal tubules with GSH (5‐15 mM) made them more refractory to the DCVC‐induced decreased PAH and TEA transport. The inhibition of active transport by DCVC is enhanced if the tubular non‐protein sulfhydryl is first lowered by diethyl maleate or glycidol. Thus, the tubular GSH concentration appears to be an integral component in regulating the alterations in active t

ISSN:0260-437X    

DOI:10.1002/jat.2550030610

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractN‐2‐Acetylaminofluorene (AAF), a potent carcinogen in a variety of animal species and organs, was used to determine the metabolic capabilities of isolated organ cells in transformation as well as biochemical studies. Cells isolated from liver, lung, small intestine, kidney and bladder were compared with hamster embryo fibroblasts (target cells in the transformation studies) and rat mammary fibroblasts in all studies. In addition to studying AAF activation by the cells, we also determined the levels of whole‐cell binding. Liver, kidney, small intestine and lung cells from hamsters, and liver, kidney and lung cells from rats showed high levels of AAF metabolism to 2‐aminofluorene andN‐hydroxy‐2‐acetylaminofluorene. The highest levels of covalent binding to intact cells were seen with the same cell types. These cells were also effective in activating AAF to a form which transformed hamster embryo cells. Cells isolated from a variety of organs can activate AAF as evidenced by the metabolites which are formed and by the levels of whole cell binding. Furthermore, hamster embryo cells are transformed when co‐incubated with a variety of orga

ISSN:0260-437X    

DOI:10.1002/jat.2550030611

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY