bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient renal impairment in rats after oral exposure to diethylene glycol
Authors: Freundt K. J. , Weis N. 
Published: October 2006

AbstractVolume, specific gravity, creatinine, lactate dehydrogenase (LDH), leucine aminopeptidase (LAP), betagalactosidase (GAL), leucocytes, erythrocytes, nitrite, protein (albumin), glucose, ketone, urobilinogen, bilirubin and pH were estimated in urine of rats after single (by gavage) or repeated (via drinking water) oral administration of diethyiene glycol (DEG). Following single or repetitive doses (daily over 90 days) of 0.2 g DEG kg−1 body weight, no change in renal function was observed (no effect level). In urine of rats treated once with 0.7 g DEG kg−1 body weight, LDH activity was significantly enhanced one day after treatment. A single dose of 2.0 g DEG kg−1 body weight resulted in an additional rise in urinary GAL activity two days after treatment, a significant rise of urinary volume and a decrease in creatinine concentration and pH on the first day. One day following a single dose of 8.0 g DEG kg−1 body weight, in addition to the changes mentioned before, LAP activity was significantly elevated and the specific gravity decreased. However, in all experiments the wet weight of the kidneys remained normal as compared to controls. The results thus show dose‐dependent changes in several renal parameters, indicating a slight‐to‐moderate and reversible renal impairment.
Carboxyhemoglobin in the rat: Improvements in the spectrophotometric measurement and comparison to other studies
Authors: Verma Kuldeep , Penney David G. , Helfman C. Clough , Sutariya Bharat B. 
Published: October 2006

AbstractAn improved and simplified spectrophotometric method for the determination of carboxyhemoglobin (COHb) is described, which employs an equation to correct for the dissociation error during analysis. Two microliters, or less, of blood is diluted with an ammonium hydroxide solution directly in the measuring cuvette. A layer of light mineral oil overlying the diluent was found to increase measured COHb saturation of blood equilibrated with 100% CO. Sodium dithionite treatment of the oil further increased this value in one case. The measured COHb was shown to be affected directly by factors that alter hemoglobin concentration in the diluent (i.e. blood volume, hematocrit). Blood samples kept cold and under oil may be stored safely for as long as 10 days. Measurement of COHb by this method in rats exposed to 525, 900, 1800 and 2400 ppm CO produces higher values than those obtained with the 1965 spectrophotometric method of Commins and Lawther. Variations on the method of Commins and Lawther, as well as COHb values available in the literature for animals exposed to CO, are reviewed briefly.
Evaluation of the developmental toxicity of five compounds with the frog embryo teratogenesis assay: Xenopus (FETAX) and a metabolic activation system
Authors: Fort Douglas J. , James Brenda L. , Bantle John A. 
Published: October 2006

AbstractThe potential teratogenic hazard of five compounds was evaluated using the Frog Embryo Teratogenesis Assay—Xenopus (FETAX) and a metabolic activation system. Embryos of the South African clawed frog, Xenopus laevis, were exposed to (i) three compounds suspected to be proteratogenic in mammalian test systems—[2‐acetylaminofluorene (2‐AAF), rifampicin (RA) and benzo[a]pyrene (BP)] for 96 h; (ii) one compound unaffected by mixed‐functional oxidase (MFO) metabolism—ZnSO4; (iii) one compound thought to be inactivated by cytochrome P‐450—cytochalasin D (CD). Two separate static renewal tests were conducted with and without the presence of an exogenous metabolic activation system (MAS). The metabolic activation system consisted of Aroclor 1254‐induced rat liver microsomes. The teratogenic potential of each compound and the effects of metabolic activation were based on teratogenic indices [TI=96 h LC50/96 h EC50 (malformation)], types and severity of malformation, and effects on embryo growth. Metabolic activation increased the potential teratogenic hazard of 2‐AAF, RA and BP by TI factors of 1.3, 2.8 and 6.8, respectively. The teratogenic potential of ZnSO4 was virtually unaffected by the MAS. The MAS significantly reduced the teratogenic potential of CD by a TI factor of 2.7. These results demonstrate the utility and importance of a MAS for in vitro developmental toxicity screens such as FETAX. Consistent use of a MAS with FETAX should reduce the number of potential false‐positive and false‐negative test results.
Mutagenicity of airborne particulates in the rubber industry
Authors: Barański Boguslaw , Indulski Janusz , Janik‐Spiechowicz Ewa , Palus Jadwiga 
Published: October 2006

AbstractThe aim of this work was to evaluate the mutagenic activity of airborne particulate matter in the rubber industry. Air was sucked through Whatman glass‐fibre filters with Staplex pumps and adsorbed substances and fume particles were extracted with acetone or toluene for 2 h in a ultrasonic cleaner. After separation of the insoluble solid phase by filtration, solvent was evaporated at a temperature of 70°C in an argon atmosphere. The residue was stored at −20°C. Mutagenicity was determined by the Salmonella plate incorporation assay with the tester strain TA98 and activity is related either to the weight of aerosol (rev mg−1) or to the volume of atmospheric sample (rev m−3). The fumes emitted from the tyre tread line, calender feeding, and tyre vulcanizing processes, showed the highest mutagenic activity (55–211 rev mg−1, + S9). At these and at other workplaces (extruder mill, carbon black station, mixer loading), mutagenic activity related to the volume of air was in the range of 22–158 rev m−3, + S9. The results indicate the need to reduce and monitor mutagenic contamination in order to increase the safety of work in the rubber industry.
Studies on some kinetic parameters of aldolases in selected tissues of the freshwater fish (Tilapia mossambica) under the toxic impact of methyl parathion
Authors: Kodavanti Prasada Rao S. , Rao K. V. Ramana 
Published: October 2006

AbstractKinetic parameters of aldolases in muscle, gill, liver and brain tissues of the teleost Tilapia mossambica were studied at sublethal concentrations with methyl parathion (MP). The pH activity profiles were optimal at pH 7.0 and 9.0 in gill, liver and brain tissues, whereas only a single peak at pH 7.0 was observed in muscle tissue of both control and MP‐exposed fish. The pH 7.0‐specific peak was confirmed as aldolase A and the pH 9.0‐specific peak represents the tissue‐specific aldolases: aldolase B in liver, aldolase C in brain and aldolase B‐C in gill. It is further confirmed with the inhibitor sensitivity of aldolases at two peaks with 6 × 10−3 M ATP or AMP. The pH‐based substrate‐dependent kinetics of aldolases showed a variable trend. The tissue‐specific activity of pH 7.0‐specific aldolases showed low Km values for gill followed by muscle, liver and brain tissues, suggestive of its high enzyme‐substrate affinity. During MP exposure, the Vmax values of pH 7.0‐specific aldolases in muscle, gill and brain were unchanged compared to controls, but Km values were decreased. The pH 9.0‐specific aldolases of gill and liver from MP‐exposed fish showed decreased Km values with a slight increase in Vmax values. Effectors such as lysine, arginine and Ca2+ inhibited, while histidine, cysteine, aspartic acid and α‐ketoglutaric acid elevated the activity levels of aldolases. It was concluded that the considerable enhancement in the catalytic efficiency of both the pH 7.0‐ and ph 9.0‐specific aldolases during MP toxicity could be due to a change in the configuration of aldolases or due to a change in the intracellular environment.
Effects of murine cytomegalovirus on development: Lack of interactions of virus and sodium salicylate
Authors: Francis B. Magnus , Huang Yuan‐Shen , Hartig Phillip C. , Rosen Mitchell B. , Kawanishi Clinton Y. , Chernoff Neil 
Published: October 2006

AbstractInteractions between exposure to xenobiotics and disease can occur during pregnancy. Few data are available on the consequences of such interactions on developmental parameters. In this study, we investigated potential interactions between murine cytomegalovirus (MCMV), which induces embryolethality, and sodium salicylate, a known teratogen. MCMV administered on Day 12 was embryotoxic over a broad range of doses from 2 × 103to 2 × 106plaque‐forming units, and also decreased postnatal weight gain. MCMV administration on Day 8 of gestation caused significant prenatal mortality regardless of salicylate. exposure. Salicylate did not cause fetal mortality or malformations at either 500 or 750 mg kg−1day−1on Days 9 and 10 of gestation. No evidence of synergistic effects of MCMV and salicylate on embryo/fetal development was seen.
Synthesis and characterization of deoxyguanosine–benzoquinone adducts
Authors: Jowa Lubow , Witz Gisela , Snyder Robert , Winkle Stephen , Kalf George F. 
Published: October 2006

AbstractBenzene expresses its carcinogenic potential in humans largely in the form of acute leukemia. Because an understanding of the formation of DNA adducts by benzene metabolites may help to explain the etiologkal role they play in benzene‐induced bone marrow disease, we have synthesized, isolated and characterized adducts formed by the reaction of deoxyguanosine with hydroquinone and p‐benzoquinone, two toxic metabolites of benzene. [3H]Deoxyguanosine and [14C]hydroquinone reacted in neutral aqueous buffer containing iron to form two dual‐labeled products, which were separated using HPLC. When p‐benzoquinone was substituted for hydroquinone, the same adducts were formed in the absence of added iron. The ultraviolet and fluorescence spectra of the less polar adduct, called Adduct 2, were distinctly different from the spectra of the starting materials. NMR and mass spectrometry suggested a compound with a mass of 357 with the p‐benzoquinone moiety bound to the N‐1 and N2 positions of deoxyguanosine. Based on these data it is proposed that Adduct 2 is (3′OH)benzetheno(1,N2)deoxyguanosine. The more polar product, Adduct 1, was found to have a unique ultraviolet spectrum but did not appear to be fluorescent. Both adducts were observed after calf thymus DNA was incubated with hydroquinone and digested to its constituent nuceosides.
Chlordecone interaction of calmodulin binding with phosphodiesterase
Authors: Vig P. J. S. , Desaiah D. , Mehrotra B. D. 
Published: October 2006

AbstractThe effects of organochlorine (O.C.) compounds, such as aldrin, dieldrin, endrin, isodrin, chiordecone and mirex, on calmodulin (CaM) activity were investigated. Changes induced by O.C compounds on biological and physical properties of CaM were monitored in terms of phosphodiesterase stimulation and tyrosine fluorescence, respectively. None of the O.C. compounds altered tyrosine fluorescence of CaM in the presence of Ca2+. Except for chiordecone, none of the O.C. compounds inhibited CaM‐activated phosphodiesterase (PDE). Chlordecone significantly decreased (P > 0.05) CaM‐activated PDE in a concentration‐dependent manner without affecting the basal enzyme. Combination of chlordecone with W‐7 (CaM antagonist) increased the inhibitory effect of W‐7 on CaM activity. These results suggest that O.C. compounds may not be changing the tyrosine fluorescence of CaM. Among the O.C. compounds tested, chiordecone is a specific inhibitor of CaM‐activated PDE.
Effect of chronic halothane exposure on lipid peroxidation, osmotic fragility and morphology of rat erythrocytes
Authors: Toker Kamil , Kartalözer Nesrin , Yalçin A. Süha , Tüzüner Sedat , Göǧüs F. Yilmaz , Emerk Kaya 
Published: October 2006

AbstractEffect of chronic halothane exposure on hepatic and erythrocyte lipid peroxidation and erythrocyte osmotic fragility and morphology were determined in rats exposed to 0.4% halothane, 8 h per day for 40 days. Hepatic lipid peroxidation was increased in the halothane‐treated group compared to controls. Lipid peroxidation was not increased by halothane exposure in erythrocytes without hydrogen peroxide, but after peroxide supplementation lipid peroxidation increased more in the erythrocytes of halothane‐exposed rats than in control rats. We have observed significant morphological changes in erythrocytes from halothane‐treated rats. In addition, erythrocytes of halothane‐treated rats were more fragile in saline solutions compared to those of controls. Our results suggest that chronic halothane exposure is not only hepatotoxic but also affects erythrocyte membrane structure and stability.
Decrease in the rat bronchial acetylcholinesterase activity after toluene diisocyanate inhalation
Authors: Brondeau M. T. , Ban M. , Simon P. , Bonnet P. , de Ceaurriz J. 
Published: October 2006

AbstractAcetylcholinesterase (AChE) activity was measured in bronchial tissue homogenate and blood from rats subjected to single and repeated 4‐h daily inhalation exposure to toluene diisocyanate (TDI) or control atmospheres. A single 4‐h exposure to TDI in the concentration range of 0.7–4.3 ppm did not decrease AChE activity in bronchial tissue but a 4‐h exposure to 0.6 ppm TDI, or greater, for two consecutive days did reduce this activity (19% to 33% of the controls). Increasing the level of exposure to TDI for two consecutive days from 0.6 to 4.0 ppm and extending the length of exposure to 1.2 ppm TDI from 2 to 4, 9 or 14 days produced no further decrease in bronchial ACHE activity. Throughout these experiments, blood AChE activity remained unchanged. In rats exposed to 0.3 or 1 ppm TDI for 3 weeks, staining of the bronchial smooth muscle for AChE was reduced (36% of the controls) after exposure to 1 ppm TDI. These results support, for the first time, in vivo and localized anti‐AChE activty by TDI.
Role of mixed‐function oxidases and non‐protein sulfhydryl contentent in [14C]‐2‐chloro‐4‐acetotoluidide binding to liver and kidney in starlings
Authors: Giri Shri N. , Siegel David M. 
Published: October 2006

AbstractThe compound 2‐chloro‐4‐acetotoluidide (CAT) is highly toxic to many avian species, including the starling. In our earlier work, we demonstrated the covalent binding of radioactivity from [14C]‐CAT to liver and kidneys of the starling. In the present study, the effects of inducers of mixed‐function oxidase (MFO) and non‐protein sulfhydryl (NPSH) depletor on the total and covalent binding of [14C]‐CAT radioactivity to liver and kidney of the starling were examined. The total and covalently bound radioactivity from [14C]‐CAT to liver and kidney were decreased significantly in the starling pretreated with the MFO inducer, 3‐methylcholanthrene. However, pretreatment with phenobarbitaf, another inducer of MFO, had no effect. Pretreatment with the inhibitor of MFO, SKF 525‐A, reduced the covalent binding of [14C]‐CAT radioactivity to liver but not to kidney. There was no reduction in the NPSH content of liver or kidney following intravenous administration of CAT (3.5 mg kg−1). Reduction of NPSH levels in the liver or kidney following treatment with diethyl maleate caused a significant increase, in the covaient binding of [14C]‐CAT to kidney but not to liver.
Basis for body weight exponent (0.75) as a scaling factor in energy metabolism and risk assessment
Authors: Sidhu Kirpal S. 
Published: October 2006

AbstractThe basis that led to the adoption of the exponent (0.75) as a scaling factor for the relationship between body weight and energy metabolism is presented. In the risk assessment formulation, it may be appropriate to use the 0.75 power of body weight as a scaling factor for carcinogenicity data obtained from animal studies.
One‐year toxicity of orally administered acrolein to the beagle dog
Authors: Parent Richard A. , Caravello Halina C. , Balmer Marilyn F. , Shellenberger Thomas E. , Long James E. 
Published: October 2006

AbstractForty‐eight dogs were separated into four groups of six males and six females. Acrolein (0.1% aqueous) was administered in gelatin capsules to three of these groups at dosing levels of 0.1, 0.5 and 1.5 mg kg−1 day−1 based on results of a range‐finding study. After 4 weeks, the high dose was increased to 2 mg kg−1 day−1. The fourth group received deionized water in the same number of gelatin capsules as the high‐dose group. Dosing was 7 days per week for 53 weeks. Blood and biochemical measurements were made pretest and at 3‐month intervals thereafter. At termination, all dogs were subjected to full necropsy and histological exmamination.The major test effect noted was frequent vomiting after dosing. This was observed to be dose‐dependent and the frequency decreased with time, indicating an adaptive effect. One mid‐dose female died during the test and was diagnosed as having died of severe bronchial pneumonia, probably a result of vomitus aspiration. Serum albumin, calcium and total protein values were depressed in high‐dose animals throughout the study. Some variability in red blood cell parameters and coagulation times were noted but the significance of these effects was not obvious.
Effect of single gallium arsenide exposure on some biochemical variables in porphyrin metabolism in rats
Authors: Flora S. J. S. , Gupta S. Das 
Published: October 2006

AbstractGallium arsenide (GaAs) inhibited, dose dependently, δ‐aminolevulinic acid dehydratase (ALAD) activity in blood (as observed on days 1, 7 and 15), liver and brain (on day 15) after a single oral treatment. Levels of blood zinc protoporphyrin (ZPP) and urinary Δ‐aminolevulinic acid (ALA) excretion were elevated on day 7 and day 15 following exposure to 2000 mg kg−1 GaAs. A dose‐dependent increase in blood As contents was observed while blood Ga was detectable only at higher doses.
Retention of inhaled perfluoroisobutene in the rat
Authors: Maidment M. P. , Upshall D. G. 
Published: October 2006

AbstractPerfluoroisobutene (PFIB) is produced by the pyrolysis, and as a by‐product during the manufacture, of polytetrafluoroethylene. When inhaled it produces a fulminating and sometimes fatal pulmonary oedema similar to that of phosgene after a latent period of 6–8 h. As part of a study to determine the retained dose and the factors that control the amount retained, this study has investigated the retention in rats of inhaled PFIB at concentrations of 10, 50 and 250 μg l−1 in a flow‐through system combining head‐only exposure and plethysmography. Uptake of PFIB was measured by gas chromatography during elevated and reduced inspired volume and respiratory rate induced by exposure to increased CO2and injection of pentobarbitone, respectively. The percentage of PFIB retained in the upper airways and lungs was found to be 27.5, 28.1 and 23.7% of the amount inspired at the three concentrations tested. The rate of uptake (nmol min−1 kg−1) of PFIB was a power law of the amount inhaled, an nb‐fold increase in minute volume producing an n‐fold increase in uptake, where b varied between 0.4 and 0.85. Thus, doubling the inhaled dose produces a 1.3–1.8‐fold increase in uptake with a corresponding decrease in percentage retained. The relative contribution of respiratory rate and tidal volume upon PFIB retention could not be defined.
Chick embryo exposure to carbamates alters neurochemical parameters and behavior
Authors: Farage‐Elawar M. , Blaker W. D. 
Published: October 2006

AbstractRecent evidence has shown that exposure to pesticides can lead to long‐term neurophysiological and functional deficits. We have demonstrated previously that locomotion in chicks exposed to some organophosphates and carbamates could be altered persistently without concomitant central or peripheral esterase inhibition. Furthermore, histopathology of the ataxic chickens showed no lesions in either the central or peripheral systems. In this study, we examined whether locomotion alterations seen in chicks exposed in ovo to carbaryl and aldicarb are accompanied by perturbations in particular central neurotransmitter systems. Carbaryl and aldicarb were injected in ovo on day 15 of incubation at 6, 16 and 65 mg kg−1 egg weight and at 0.2, 0.4 and 3.5 mg kg−1 egg weight, respectively. Neurotransmitter levels (assayed by high performance liquid chromatography with electrochemical detection) and locomotion were measured at various times (1–43 days) after dosing. At the lower doses of both carbaryl and aldicarb, a trend towards prolonged decreases in cerebral dopamine and homovanillic acid was seen. The high dose of carbaryl significantly reduced dopamine and the high dose of both compounds significantly decreased homovanillic acid and 5‐hydroxyindoleacetic acid. Persistent locomotion alterations were observed only at the higher doses of both carbaryl and aldicarb when the specific neurotransmitters measured returned to normal levels.
Cell proliferation in the respiratory tract of the rat after acute inhalation of formaldehyde or acrolein
Authors: Roemer E. , Anton H. J. , Kindt R. 
Published: October 2006

AbstractMale Sprague Dawley rats were exposed by inhalation for 6 h per day on one or three successive days to 0, 2, 6 or 20 ppm formaldehyde or 0, 0.2 or 0.6 ppm acrolein. Nasal and tracheal epithelial and free lung cells were then analyzed for proliferative responses. The proliferative response was expressed as the proportion of DNA synthesizing cells determined by the 5‐bromodeoxyuridine (BrdU) labelíng technique.Single exposure to both irritants increased the DNA synthesizing (proliferating) cells by a factor of 3. After three exposures the increase was distinctly lower. All sites analyzed showed approximately the same concentration/response pattern. Significant changes in cell proliferation could be detected at 2 ppm formaldehyde and 0.2 ppm acrolein.
Oral toxicity in weanling and adult rats and in vitro Genotoxicity of the Veterinary Anthelmintic Rafoxanide
Authors: Poul J. M. , Verlinde V. , Abjean J. P. , Laurentie M. 
Published: October 2006

AbstractThe oral toxicity of the veterinary anthelmintic Rafoxanide was evaluated in newborn rats exposed in utero and during lactation. In another group, 3 months of oral treatment started after weaning. Rafoxanide administration to dams (10 mg kg−1) decreased the number of pups per litter, induced high mortality (42%) and delayed the growth of offsprings before weaning. Histopathological examination of the central nervous system revealed vacuolation of the white matter. Vacuolation was particularly severe in the cerebellum of the 14–21‐day‐old rats. Rafoxanide induced, in some pups (35%), the formation of cataracts. These toxic effects seemed to be reversible and were no longer detectable after a further 3‐month administration of Rafoxanide (10 mg kg−1) to rats born of treated dams. In adult rats treated orally for 3 months with 1, 5 or 25 mg kg−1 Rafoxanide, biochemical and haematological tests did not reveal dose‐related effects. Rafoxanide had no mutagenic activity in the Ames and CHO/HGPRT tests.