bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of chlorine and monochloramine in drinking water on the developing rat fetus
Authors: Abdel‐Rahman Mohamed S. , Berardi Mark R. , Bull Richard J. 
Published: October 2006

AbstractChlorine dioxide (ClO2) or monochloramine (NH2Cl) may be considered as an alternative to chlorine (HOCl) as a disinfectant in public water supplies, since chlorination produces trihalomethanes. This study was conducted to determine the effect of chlorine and monochloramine on rat fetuses. Female rats were administered 0, 1, 10 or 100 mg l−1 NH2Cl or HOCl daily in the drinking water for 2 1/2 months prior to and throughout gestation. Rats were sacrificed on Day 20 of gestation and fetuses were preserved for soft‐tissue and skeletal examination. No significant increase in fetal resorptions was found in any treated group. A slight increase in skeletal variants (such as incompletely ossified or missing sternebrae, or rudimentary ribs) was seen in 10 and 100 mg l−1 HOCl groups. Soft‐tissue defects, mainly improper orientation of the heart or adrenal agenesis, were observed in the 100 mg l−1 HOCl group. The percentage of total defects (skeletal and soft‐tissue) was increased significantly over control in the 100 mg l−1 HOCl group; however, monochloramine did not produce any significant changes in rat fetuses at any dose level.
Comparative toxicokinetics of 2,3‐14C‐ and 1‐14C‐acrylonitrile in the rat
Authors: Ahmed Ahmed E. , Farooqui Mohammed Y. H. , Upreti Raj K. , El‐Shabrawy Osama 
Published: October 2006

AbstractThe tissue distribution, elimination and covalent binding of 2,3‐14C‐ and 1‐14C‐acrylonitrile (VCN) were studied in male Sprague—Dawley rats given an oral dose of 46.5 mg kg−1. Exhalation of unchanged VCN, 14CO2 and H14CN was monitored at selected intervals. Only 5% of the total dose administered was recovered as unchanged VCN. Rats given 2,3‐14C‐VCN exhaled only 2% of 14C activity as 14CO2 and none was recovered as H14CN, whereas rats given 1‐14C‐VCN exhaled about 12% of 14C activity as 14CO2 and 0.5% as H14CN. In the initial 24 h, 40% of radioactivity from 1‐14C‐VCN appeared in urine, while 60% was recovered in the urine of rats given 2,3‐14C‐VCN. The red blood cells retained significant amounts of radioactivity from both the compounds for more than 10 days after administration, whereas the 14C activity in plasma declined sharply. The highest level of radioactivity from both compounds was recovered in the gastrointestinal tract. In liver, kidney, brain, spleen, adrenal, lung and heart tissues the unbound percent radioactivity decreased, while irreversible percent covalent binding to macromolecules in relation to total increased concomitantly. Subcellular fractionation of the tissues showed that most of the covalently bound radioactivity was distributed in non‐cytosolic fractions. As compared to 1‐14C‐VCN administered animals, the percentage of covalent binding of 2,3‐14C‐VCN was significantly higher even 72 h after dosing. The relationship between covalent binding and acrylonitrile toxicity is discussed.
Genetic Toxicology Association – Fall Meeting 1984
Authors: Szabo Paul , Henderson Ann S. , D'Eustachio Peter 
Published: October 2006

AbstractThe Fall Meeting of GTA was held on 15 November 1984 at Eatontown, New Jersey. The topic for this meeting, ‘Molecular Approaches to Cancer', was addressed by three invited speakers: Paul Szabo, Ann Henderson and Peter D’ Eustachio. A panel discussion, moderated by Ronald Pero, followed these talks. The following are abstracts of the talks given by the main speakers.
Effects of phthalic acid esters on drug metabolizing enzymes of rat liver
Authors: Gollamudi R. , Lawrence W. H. , Rao R. H. , Autian J. 
Published: October 2006

AbstractDi(2‐ethylhexyl)phthalate (DEHP) inhibited UDP‐glucuronyltransferase activity of rat liver in vitro and in vivo. Diethyl phthalate and dimethoxyethyl phthalate also inhibited this enzyme in vitro. On the other hand, DEHP did not inhibit the activity of the cytosolic enzyme N‐acetyltransferase; it also did not alter the levels of rat liver microsomal cytochrome P‐450 in vitro. It is suggested that DEHP may alter the composition of microsomal phospholipids.
The effect of exposure duration on the blood level of glucose pyruvate and lactate in acute carbon monoxide intoxication in man
Authors: Sokal J. A. 
Published: October 2006

AbstractBlood glucose, pyruvate and lactate were examined during hospitalization of 13 cases of acute carbon monoxide poisoning developing from short (≦ 1.5 h) or long (10–14 h) exposure. CO intoxication resulted in increased blood levels of all carbohydrate metabolites studied. Increased levels of pyruvate and lactate were much more pronounced and lasted for a longer time following long, compared with short, CO exposure despite similar blood COHb level (about 40% at the beginning of hospitalization).The results showed difference in biochemical effect of short and long single exposure to CO that could not be detected by the measurement of COHb.
Toxicity of aromatic disulphides. III. In vivo haemolytic activity of aromatic disulphides
Authors: Munday R. , Manns E. 
Published: October 2006

AbstractDiphenyl disulphide, 4,4′‐diaminodiphenyl disulphide, 2,2′‐diaminodiphenyl disulphide, 4,4′‐dimethyl‐diphenyl disulphide and 4,4′‐dintrodiphenyl disulphide, when administered orally to rats, induced haematological and pathological changes indicative of erythrocyte destruction in vivo. No evidence of haemolysis was detected, however, in animals receiving diphenyl disulphide‐2,2′‐dicarboxylic acid or dibenzyl disulphide. The order of activity of the various aromatic disulphides in provoking in vivo haemolysis was similar to that previously recorded for ‘active oxygen’ generation and erythrocyte damage in vitro.The results of this investigation suggest that in vivo haemolysis may be anticipated from any disulphide or thiol which undergoes appreciable autoxidation at neutral pH. While aromatic or αβ‐unsaturated thiols and disulphides would be expected to be the most active haemolytic agents, other thiols or disulphides may precipitate the destruction of erythrocytes whose defences against oxidative attack are deficient.
Chronic effects on the respiratory tract of hamsters, mice and rats after long‐term inhalation of high concentrations of filtered and unfiltered diesel engine emissions
Authors: Heinrich U. , Muhle H. , Takenaka S. , Ernst H. , Fuhst R. , Mohr U. , Pott F. , Stöber W. 
Published: October 2006

AbstractA long‐term exposure study with hamsters, mice and rats inhaling filtered and unfiltered diesel engine exhaust was carried out to investigate effects of chronic toxicity and, predominantly, carcinogenicity in the respiratory tract. The level of diesel exhaust in the exposur chambers corresponded to a concentration close to 4 mg m−3 in the unfiltered diesel exhaust. Satellite groups of animals were additionally treated with BaP, DBahA or nitrosamines in order to check for syncarcinogenic effects.In hamsters and rats, alveolar lung clearance and mechanical lung function tests as well as biochemical and cytological measurements in lung lavage fluids showed significant changes only after exposure to unfiltered diesel exhaust and, predominantly, in rats.No lung tumors were found in hamsters. Spontaneous tumor rates occurred in mice and both types of diesel exhaust increased the incidence of adenocarcinomas in the lungs. In rats, only the unfiltered diesel exhaust caused a lung tumor incidence. It amounted to 16% with no tumors in the controls.The heavy load of particulate matter in the lungs of rats was caused by an exposure‐related impairment of the alveolar lung clearance and may have been instrumental in the induction of squamous cell tumors. However, an effect of particle‐associated PAH cannot be excluded. Syncarcinogenic effects of diesel exhaust after initial carcinogen treatment were found only in the respiratory tract of rats.
Changes in cerebral glycogenolysis and related enzymes in diazinon treated hyperglycaemic animals
Authors: Matin M. A. , Husain Kazim 
Published: October 2006

AbstractEffect of diazinon (10,20 and 40 mg/kg, i.p.) on the level of blood glucose in rats was investigated. Hyperglycaemia peaked 2 h after i.p. treatment with 40 mg/kg diazinon. The cerebral acetylcholinesterase activity was significantly reduced. The blood level of pyruvic acid was unchanged while that of lactic acid was significantly increased. Convulsions and biochemical changes caused by diazinon (40 mg/kg) were prevented by diazepam injected immediately after diazinon. In diazinon‐treated hyperglycaemic animals, the glycogen content of the brain was depleted, the activities of glycogen phosphorylase, phosphogiucomutase and hexokinase were significantly increased and the activity of glucose‐6‐phosphatase remained unchanged. Lactate dehydrogenase activity was also increased by treatment with diazinon. The induced changes may compensate for the energy requirement of stimulatory effects caused by diazinon.
The relationships of urinary metallothionein with other indicators of renal dysfunction in people living in a cadmium‐polluted area in Japan
Authors: Tohyama Chiharu , Mitane Yuko , Kobayashi Etsuko , Sugihira Naoko , Nakano Atsuhiro , Saito Hiroshi 
Published: October 2006

AbstractAn epidemiologic investigation was carried out to study the significance of urinary excretion of metallothionein (MT) in people aged 50 years and over living in a cadmium (Cd)‐polluted area in Japan. The urinary level of MT was compared with various parameters (age, urinary α1‐microglobulin (α1‐MG), β2‐microglobulin (β2‐MG), total protein, Cd, copper (Cu), and zinc (Zn), and relative clearances to creatinine of α1‐MG, β2‐MG, phosphate and uric acid). It was found that the urinary excretion of MT is closely associated with Cd and the indices of renal dysfunction listed above. This observation was more remarkable in women than men. When subjects with signs of renal dysfunction were compared as a group to those with normal renal functions, the excreted amount of MT in the former is significantly greater. The results support the notion that the urinary excretion of MT reflects not only Cd exposure levels but also renal dysfunction caused by long‐term Cd exposure.
Hemoglobin adducts in animals exposed to gasoline and diesel exhausts 1. Alkenes
Authors: Törnqvist M. , Kautiainen A. , Gatz R. N. , Ehrenberg L. 
Published: October 2006

AbstractBlood samples from rats and hamsters exposed to automotive engine exhausts in the Committee of Common Market Automobile Constructors long‐term inhalation study at Battelle‐Geneva were analysed for the levels of 2‐hydroxyethylvaline (HOEtVal) and 2‐hydroxypropylvaline (HOPrVal) in hemoglobin (Hb). These adducts to the N‐terminus of the Hb chains were determined by gas chromatography‐mass spectrometry of derivatives obtained by a modified Edman degradation that specifically cleaves off alkylated N‐terminal amino acids (valine in Hb).The adduct levels found correspond to the metabolic conversion of about 5–10% of inhaled ethene and propene to ethylene oxide and propylene oxide, respectively, in agreement with results from earlier studies on mice inhaling radio‐labelled alkenes. It is concluded that the alkenes, via epoxides, are the main sources of the observed HOEtVal and HOPrVal. From calculated doses and estimates of genotoxic potency the contribution from ethene in urban air to human cancer risk is discussed.
Toxicity of gallium oxide particles following a 4‐week inhalation exposure
Authors: Wolff R. K. , Henderson R. F. , Eidson A. F. , Pickrell J. A. , Rothenberg S. J. , Hahn F. F. 
Published: October 2006

AbstractTo evaluate the inhalation toxicity of Ga2O3, F344 rats were exposed nose‐only to 0.2 μm Ga2O3 particles 2 h/day, 5 days/week for 4 weeks. The exposure concentration was 23 ± 5 mg/m3 (mean ± SD) resulting in lung burdens of 0.8 ± 0.1 mg Ga2O3/lung (mean ± SE) at the end of 4 weeks of exposure. Analysis of bronchoalveolar lavage fluid of exposed rats showed marked responses. One day after termination of exposure, lactate dehydrogenase was increased 6‐fold, and the lysosomal enzyme, beta‐glucuronidase, was increased 38‐fold in rats exposed to Ga2O3 compared to sham exposed controls. Alkaline phosphatase, glutathione reductase, glutathione peroxidase, white blood cells, acid proteinase, and protein were increased 3‐ to 4‐fold. Responses remained elevated 6 and 12 months after exposure. Lung clearance of radiolabeled tracer particles was evaluated 4 days and 6 months after the end of 4 weeks of Ga2O3 exposures. Long‐term clearance half‐times were significantly longer| (3–4 fold, P <0.01) in rats exposed to Ga2O3 than in the sham‐exposed control rats at both 4 days and 6 months, indicating persistent impairment of particle clearance. Histopathological lesions consisted primarily of alveolar proteinosis 1 day after 4 weeks exposure, progressing in severity to large focal lesions of alveolar histiocytosis and septal fibrosis 6 and 12 months after exposure. Inhaled Ga2O3 produced cytotoxic, inflammatory, and fibrogenic responses of comparable or greater magnitude than those seen after similar exposures of rats to inhaled quartz particles in other studies. These data show that inhaled Ga2O3 particles produce considerable toxicity and exposures in the work place should be limited.
Reaction of macrophages activated by agents in vivo to quartz dust in vitro
Authors: Kaw Jawahir Lal , Waseem Mohd 
Published: October 2006

AbstractA comparative study was made of the cytotoxic action of quartz dust in vitro on macrophages activated in vivo by intraperitoneal inoculation of physiological saline, thioglycolate and starch. The liberation of lactate dehydrogenase (LDH) into the supernatant culture medium, adherence to a plastic surface, extent of acid dye exclusion and ultrastructural alteration in the surface morphology of macrophages were taken as parameters of the cytotoxic action of the dusts. Thioglycolate and starch stimulated cells when exposed in vitro to quartz dust released more LDH into the supernatant culture medium and resulted in a greater decrease in macrophage adherence than similarly exposed cells derived from saline stimulated animals. No difference was observed between cells obtained from differently stimulated animals in increased acid dye uptake, loss of surface filopodia and rounding of cells which phagocytosed quartz particles. The results show that quartz is cytotoxic for macrophages, irrespective of their degree of activation and the extent of damage induced is related to the chemical agent used for activation of macrophages in vivo.
Developmental and sex differences in cadmium distribution and metallothionein induction and localization
Authors: Blazka Mark. E. , Nolan Canice V. , Shaikh Zahir A. 
Published: October 2006

AbstractAge‐ and sex‐related differences in hepatic and renal distribution of cadmium (Cd) and the effect of Cd injection (10 μmol/kg) on tissue zinc (Zn), copper (Cu) and metallothionein (MT) levels were investigated in 2‐ to 84‐day old rats. Renal Cd accumulation increased with age of the animal. Sex differences in renal Cd accumulation were noted in young animals where the 2‐ and 8‐day old males had significantly greater concentration than the females. There were no clear effects of Cd on renal Zn. Renal Cu levels, however, were elevated in the adults. The adult females contained about twice as much MT as the adult males. Cd treatment had no effect on renal MT levels of 8‐ to 84‐day old animals but depressed the levels in 2‐day old. Age‐related increase in hepatic Cd accumulation was also found; the pattern was more clear cut in females than in males. In addition, in the females the hepatic Cd concentration was significantly higher than in the males. Cd‐injection significantly increased hepatic Zn and MT concentrations only in weaned animals. While there were no sex differences in MT levels in the young animals, the weaned females had significantly more MT than the corresponding males. Immunohistochemical staining for MT showed positive staining in both cytoplasm and nuclei of the parenchymal cells. The number of MT‐positive nuclei was dependent on the relative MT concentration of the liver. In spite of the intense nuclear staining in 2‐day old controls and 84‐day old Cd‐injected rats, less than 1% of the hepatic MT was present in the nuclear fraction. The above data on the tissue distribution of Cd point to the possible effects of sex hormones on Cd metabolism. The results of the intracellular distribution of MT suggest that nuclear MT represents only a minute fraction of the total cellular MT, even in the neonatal rat.
Instability and apparent lack of metabolism of phomopsin a during incubation with ovine rumen fluid
Authors: Vogel Paul 
Published: October 2006

AbstractTo investigate the stability and possible metabolism of phomopsin A in rumen fluid, phomopsin A was incubated in ovine rumen fluid ‐ buffer mixtures for 24 h. High performance liquid chromatographic analysis of extracted incubation mixtures demonstrated that although phomopsin A was degraded, metabolism by rumen microorganisms appears not to be important during 24 h incubation.
Mitochondrial and microsomal lipid peroxidation in rat liver after acute acetaldehyde and ethanol intoxication
Authors: Uysal Müjdat , Özdemirler Gül , Kutalp Güldal , Öz Hikmet 
Published: October 2006

AbstractThe effects of acetaldehyde and ethanol treatments on hepatic lipid peroxidation are compared in rats after the administration of toxically corresponding doses. Wistar rats were given a single dose of acetaldehyde (0.5 g/kg) or ethanol (5 g/kg) intraperitoneally. The animals were killed 1/2, 1, 2, 4, 6, 9, 12 and 24 h after treatments. The results indicate that acetaldehyde, like ethanol, stimulates hepatic lipid peroxidation and also selectively affects the hepatic mitochondria.
The effects of thiamin on the tissue distribution of lead
Authors: Kim Jin Suk , Blakley Barry R. , Rousseaux Colin G. 
Published: October 2006

AbstractThe effects of thiamin on the tissue distribution of lead were evaluated in Sprague–Dawley rats exposed to 1000 ppm lead acetate in drinking water and treated daily with thiamin (25 or 50 mg kg−1 body weight, i.p.), calcium ethylenediamine tetraacetic acid (50 mg kg−1 body weight, i.p.) or their combination for 8 weeks. The subtoxic dose of lead did not alter weight gains, feed and water consumption during the treatment period. Thiamin decreased the blood (P > 0.0001), liver (P < 0.0001) and kidney (P < 0.0001) concentrations of lead. Thiamin (50 mg kg−1 body weight) reduced the lead concentrations in tissues more effectively than thiamin (25 mg kg−1 body weight). The combined treatment was more effective than the respective individual treatments.
Isoniazid potentiation of a guinea pig model of halothane‐associated hepatotoxicity
Authors: Lind Richard C. , Gandolfi A. Jay , de la M. Hall Pauline 
Published: October 2006

AbstractIsoniazid (INH) is a selective inducer of cytochrome P‐450 isozymes that are involved in the biotransformation of organohalogen anesthetics. It has been used to produce a rat model of halothane‐associated hepatotoxicity that was linked to enhanced oxidative biotransformation of the anesthetic. Guinea pigs were pretreated with INH in order to potentiate halothane‐induced hepatic necrosis and to study the oxidative pathway as a hepatotoxic mechanism in this species. The animals received either 12.5, 25.0 or 50.0 mg kg−1 INH i.p. for 7 days. Following halothane exposure, there were dose‐dependent increases in plasma levels of the oxidative halothane metabolite, trifluoracetic acid. These increases were associated with increases in 48 h plasma alanine aminotransferase (ALT) levels. When combined with halothane exposure, the two higher doses of INH killed the animals before planned termination. These deaths were not attributable to hepatic failure. Dividing the 25 mg kg−1 INH dose into twice daily injections of 12.5 mg kg−1 reduced deaths. INH pretreatment control animals exhibited occasional non‐dose‐dependent increases in ALT as well as the occurrence of fatty vacuolization of hepatocytes at the highest dose. Even though INH pretreatment enhanced oxidative halothae biotransformation and subsequent hepatotoxicity, sensitivity of guinea pigs to the deleterious actions of INH would contraindicate its use as a cytochrome P‐450 induction agent.
Characterization of lymphocyte subpopulations in the blood of the cynomolgus monkey using flow cytometry
Authors: Sagara Nami , Furuhama Kazuhisa , Onodera Takeshi 
Published: October 2006

AbstractThis study was performed to assess the usefulness of flow cytometry in comparison with acid alpha‐naphthyl acetate esterase (ANAE) staining for the enumeration of lymphocyte subpopulations in cynomolgus monkeys. For flow cytometry, use was made of mouse antihuman leukocyte monoclonal antibody (T11), recognized to undergo cross‐reaction with monkey T lymphocytes or antimonkey IgG serum labelled with fluoroscein isothiocyanate. The percentages of lymphocyte subpopulations in mononuclear cells of thirty healthy female cynomolgus monkeys were 72.1 ± 2.4% for T cells and 24.6 ± 2.4% for B cells as assayed by flow cytometry evaluation, and 63.8 ± 2.5% for T cells and 15.8 ± 2.2% for B cells as determined by ANAE staining. Although the percentage of T cells shown by ANAE staining was significantly lower than that seen with flow cytometry, the coefficient of correlation indicated a close correlation in both T and B cell subsets between these two methods. In monkeys receiving 20 mg kg−1 cyclophosphamide daily for 14 days, counts of all leukocytes and T and B cells were decreased, whereas animals treated with 1.0 mg kg−1 muroctasin daily for 14 days showed higher monocyte and neutrophil counts without changes in T or B cells. These results suggest that flow cytometry evaluation has several advantages over ANAE staining with respect to rapidity and precision in toxicological studies using large numbers of monkeys.
Influence of metyrapone and phenobarbital on sodium dichromate nephrotoxicity in developing rats
Authors: Appenroth D. , Gambaryan S. , Friese K.‐H. , Bräunlich H. 
Published: October 2006

AbstractAfter the administration of equal doses of sodium dichromate, chromium concentrations in the kidney were lower in young than in adult rats. To test the age‐dependent sensitivity to the nephrotoxicity of dichromate, young and adult rats were given doses to achieve identical chromium conceätrations in the kidney. At equal renal concentrations, young rats had less functional and morphological damage than adult rats. As phenobarbital treatment in young rats enhanced the symptoms of nephrotoxicity and metyrapone treatment in adult rats decreased the symptoms of nephrotoxicity, age‐dependent differences in chromate nephrotoxicity may be linked to an increase in the enzymatic reduction of Cr(VI) with age.
A genotoxicological study of the new local anesthetic carbamate derivatives Carbisocaine, heptacaine and pentacaine
Authors: Siekel Peter 
Published: October 2006

AbstractThe potential mutagenic activity of three carbamate derivatives with local anesthetic activity was investigated. Genotoxic activity was observed after application of Carbisocaine on Euglena gracilis, whereas no activity was detected by Carbisocaine, Heptacaine and Pentacaine on Salmonella typhimurium, Escherichia coli and Drosophila melanogaster.