bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion rate of non‐chelatable to chelatable lead after CaEDTA injection: A kinetic study in two lead workers
Authors: Arak Shunichi , Murata Katsuyuki , Yokoyama Kazuhito , Aono Hiroshi , Yanagihara Susumu , Ushio Koichi 
Published: October 2006

AbstractDiminution rate of body burden of chelatable lead (CPb) after injection of calcium disodium ethylenediamine tetraacetate (CaEDTA) was estimated at between 0.7 and 0.4% per week in two lead workers after termination of lead exposure. Hence, alteration in body burden of CPb during the week after a single injection of CaEDTA was simulated by two different equations. The first equation was (1 + α−1.3β)6 (1–1.03k + α) A = 0.993A or 0.996A, where A = body burden of CPb just before CaEDTA injection; α = proportion of CPb converted from non‐chelatable lead (NPb) to A during the 24 h after CaEDTA injection; k = proportion of 24‐h mobilization yield of lead by CaEDTA to A; and β = proportion of 24‐h spontaneous urinary lead excretion to A. This equation was based on the assumption that the amount of lead converted to CPb during 24 h was proportional to the initial level of CPb. The second equation, i.e. (1–1.03k) (1–1.3β)6 A + {(1–1.3β)6 + (1–1.3β)5 + … + (1–1.3β) + 1} αA = 0.996A or 0.996A, assumed that the amount of lead converted to CPb during 24 h was nearly constant during a week after CaEDTA injection. The conversion rate (α) was obtained as a solution of each equation after determination of k and β according to our model. It was estimated that the amount of lead corresponding to 2% of body burden of CPb, i.e. 0.23 mg and 0.35 mg, was converted from NPb to CPb during the 24 h after CaEDTA injection in the two lead workers with blood lead concentrations of 44 μg per 100 g and 61 μg per 100 g, respectively. A previous model for estimating body burden of CPb from mobilization yield of lead by CaEDTA was amended in the light of this estimation.
Investigation of the interaction between Probon® and indomethacin in rats
Authors: Sebestyén Gyula , Gergely Vera , Virág Sándor , Mészáros Zoltán 
Published: October 2006

AbstractThe toxic side‐effects and anti‐inflammatory activity of combination treatment of Sprague‐Dawley rats with indomethacin and Probon, a new type of analgesic, were investigated. Following four weeks of treatment with a combination of these two drugs, the characteristic gastrointestinal side‐effect of indomethacin was markedly reduced. Mortality resulting from administration of the drug combination was significantly lower than that resulting from indomethacin treatment alone. The reduced toxicity of indomethacin in combination with Probon is probably due to a change in metabolism produced by the hepatic microsomal enzyme inducer, Probon. The anti‐inflammatory effect was also investigated using a contact thermographic method following one, three or seven days pretreatment. The advantage of this combination is that, using a higher dose of indomethacin in combination with the minor analgesic, we could achieve a more reliable anti‐inflammatory effect together with a pain‐killing action.
Hormonal changes and adenylate cyclase system in rats bearing 7800 Morris Hepatoma
Authors: Mourelle Marisabel 
Published: October 2006

AbstractAdenylate cyclase activity was measured in plasma membranes isolated from Morris Hepatoma 7800 and from control and host livers. The only difference found in tumor enzyme activity was the lack of response to glucagon. The membrane‐binding capacities for the pancreatic hormones insulin and glucagon were measured. Hepatoma membranes did not bind glucagon. Insulin‐binding parameters could not be determined because of high non‐specific binding. The plasma levels of insulin in the tumor‐bearing animals were approximately half of those found in controls, whereas the glucagon levels in plasma were 50% higher in tumor‐bearing animals. Thyroxine and triiodothyronine plasma levels were reduced in tumor‐bearing rats, while the thyroid‐stimulating hormone level was within normal limits. The amount of cAMP (275 pmol g−1) and cGMP (3.6 pmol g−1) in the tumor were lower than in the host and control livers, but the ratio of cGMP to cAMP in the tumor was increased by a factor of 2. These results are discussed with respect to control mechanisms of cell proliferation in comparison with other hepato‐proliferative states.
Fibrogenic potential of welding fumes
Authors: Stern R. M. , Pigott G. H. , Abraham J. L. 
Published: October 2006

AbstractA search of 3600 indexed pathology cases has disclosed pulmonary fibrosis in 29 welders. Scanning electron microscopy of biopsy material revealed macrophages laden with inorganic particulates which have characteristics compatible with welding aerosols. In order to establish a possible relationship between fibrotic reaction and welding‐fume exposure, the fibrogenic potential of some 11 different welding fumes and metallic aerosols, considered to be reference standard surrogates for the commonly used welding technologies and applications responsible for 70% of welders exposure, were screened using the Rat Peritoneal Macrophage in vitro bioassay. Only one class of fumes, that from the manual metal arc welding of stainless steel, showed distinct fibrogenic potential. This fume is, however, not common to more than four or five of the heretofore 90 cases of pulmonary fibrosis reported among welders. Thus, although insoluble Cr(VI) is probably the active fibrogen in stainless steel fumes, an etiological factor common to all fibrogenic welding exposures must be sought. It is tentatively proposed to be NO2, a potent experimental in vivo fibrogen copiously produced by certain welding processes and ubiquitous at low concentrations in the welding environment.
A generalized extraction‐TLC procedure for indentification of drugs
Authors: Warfield Robert W. , Maickel Roger P. 
Published: October 2006

AbstractA combination of liquid—liquid extraction and thin‐layer chromatography permits rapid identification of a large variety of drugs in pharmaceutical or street dosage forms, or in biological materials. The system utilizes selective pH extraction combined with internal standards. Limits of sensitivity are in the sub‐microgram level. The procedure is rapid and requires minimal equipment and training of personnel. It can be applied to situations in toxicology involving both clinical and forensic demands.
Detectability in vivo of stabilized intercalating agents with the alkaline elution technique comparison with in vivo sister chromatid exchange induction
Authors: Russo Patrizia , Pala Mauro , Ottaggio Laura , Vecchio Daniela , Santi Leonardo , Parodi Silvio 
Published: October 2006

AbstractThe purpose of the work reported here was to investigate, with the alkaline elution technique, the capability of in vivo administered actinomycin D, daunomycin and mitomycin C to induce DNA damage, DNA interstrand cross‐linking and DNA‐protein cross‐linking. The ability of these compounds to induce increases in sister chromatid exchange (SCE) in the bone marrow cells of mice was also investigated. Actinomycin D and daunomycin were active in inducing single strands breaks, while mitomycin C was inactive. Mitomycin C showed a clear DNA interstrand cross‐linking activity, while this activity was absent in actinomycin D and daunomycin. All three compounds were positive for SCE induction, but mitomycin C was by far the most active compound. Our results seem to suggest that stabilized intercalating agents are often detectable with the alkaline elution technique, after treatment in vivo. However, they cannot be evaluated with the simple alkaline elution technique only. It is convenient to add to the basic method the modification for detecting cross‐links. Finally, DNA interstrand cross‐linking and sister chromatid exchanges could be correlated.
The experimental administration of lead to rats in neuropathological and behavioural studies
Authors: Winder Christopher , Carmichael Neil G. 
Published: October 2006

AbstractThe experimental investigation of the effects of lead have been studied for nearly 20 years. In that time, a variety of neurobiological processes have been reported to be altered following ingestion of lead. Most routes of administration and a bewildering number of doses have been employed to administer lead to experimental animals. However, inadequate characterization of dose regimes has impaired understanding of any effects, and their correlation to conditions of human exposure. As an index of lead burden, blood lead remains the most reliable means of assessing recent lead absorption. It is clear that a large number of model systems and dosing regimes do not address the problems of human clinical or subclinical lead intoxication. It is also clear from brain lead measurements in experimental animals that lead is selectively sequestered into specific areas of the control nervous system.
Methylmercury poisoning in Iraq. An epidemiological study of the 1971—1972 outbreak
Authors: Greenwood Michael R. 
Published: October 2006

AbstractFollowing the Iraq methylmercury poisoning epidemic in 1971–72, surveys were conducted on selected rural populations to determine the extent of exposure to methylmercury. It was calculated that 40% of those receiving treated grain will have consumed it. Study of death registries in three provincial capitals and their Qada centers reveals that, in the year November 1971 to October 1972, more deaths occurred than in the corresponding period of other years. These deaths were in addition to the 459 deaths which occurred in hospitals. Deaths for the 1–10 and 11–20 year age groups during the year 1971–72 were four‐fold higher than the mean of the two preceding and two following years. However, when adjusted for the age distribution of the population, no one age group had a statistically significant higher incidence of poisoning. Registered live births decreased in 1973, the year following the epidemic, but, at the present time, there is not sufficient information to know the significance of this decrease.
The effect of handling techniques on serum alt activity in mice
Authors: Swaim L. D. , Taylor H. W. , Jersey G. C. 
Published: October 2006

AbstractThe effect of handling mice by the tail or by the body on serum alanine transaminase (ALT) activity was investigated in normal mice and in mice pretreated with a known hepatotoxin. In normal mice, the mean ALT activity 1 h after grasping the body was almost four times greater than in the control (not‐handled) and tail‐handled groups. However, when ALT analyses were repeated 1 week later, all groups were equivalent. In mice given a hepatotoxic dose of 30 mg kg−1 carbon tetrachioride, the mean ALT activity was approximately three times greater in mice handled by the body than in mice grasped by the tail only. Handling mice by the body may reduce the usefulness of ALT activity as a measure of hepatotoxicity.
Dermal absorption of pesticides calculated by deconvolution
Authors: Fisher Henry L. , Most Bernard , Hall Larry L. 
Published: October 2006

AbstractUsing published human data on skin‐to‐urine and blood‐to‐urine transfer of 12 pesticides and herbicides, the skin‐to‐blood transfer rates for each compound were estimated by two numerical deconvolution techniques. Regular constrained deconvolution produced an estimated upper limit on cumulative dermal absorption of the radiolabel, while minimized deconvolution produced an upper bound on cumulative dermal absorption of parent compound. Dermal absorption rate was largest within 8 h of dosing for all pesticides examined. Only carbaryl showed a lag (3.5 h) in penetration. This may indicate a prolonged transit time through skin or a chemical transformation in skin has occurred. After onset, absorption occurred rapidly with 45% of the 120 h cumulative absorption occurring in 8 h. For parathion and dieldrin, over 50% of the 120 h total absorption occurred in the first 4 h. The deconvolution technique described here permits the calculation of the temporal aspect of dermal absorption for linear systems.
The effect of alcide®, a new antimicrobial drug, on rat blood glutathione and erythrocyte osmotic fragility, in vitro
Authors: Abdel‐Rahman Mohamed S. , Scatina Joann 
Published: October 2006

AbstractAlcide† is an antimicrobial drug which has been demonstrated to kill a variety of common pathogenic bacteria as well as fungi, in vitro. This agent is supplied in liquid and gel forms and consists of two parts, one of which contains sodium chlorite, while the other contains lactic acid as the active ingredients. Mixing of the two parts prior to use produces chlorine dioxide (ClO2), a strong oxidizing agent. A dose‐dependent decrease in glutathione content and erythrocyte osmotic fragility occurred after incubation of whole blood with alcide®. Glutathione concentration and erythrocyte osmotic fragility approached the control values after 240 min of incubation with alcide® containing 1 mM NaClO2. The addition of exogenous glutathione (50 mg 100 ml−1) or glutathione reductase and NADPH to rat blood in the presence of alcide® returned erythrocyte osmotic fragility to control values. Treatment of rat blood with alcide® did not change glutathione reductase or glutathione peroxidase activities after 1 h of incubation.
Stability of aroclor 1254–induced rat liver postmitochondrial supernatant (s‐9) following long‐term storage (−75°c)
Authors: Oldham James W. , Pritchard J. Frederick , Preston Robert F. , Nomides Charles T. , Patton Wanda E. , Paulson John D. 
Published: October 2006

AbstractThe stability of Aroclor 1254‐induced rat liver postmitochondrial supernatant (S‐9) over a 5‐year period was investigated in a retrospective study. S‐9 was uniformly prepared at 6‐month intervals, and aliquots were stored at −75°C. The protein and cytochrome P‐450 content of these lots of S‐9 were very similar, and no differences attributable to duration of storage were observed in the activities of ethoxycoumarin O‐deethylase, aniline hydroxyiase, cytochrome P‐450 reductase or aryl hydrocarbon hydroxylase. There was no decrease following 5 years of storage in the ability of S‐9 to activate 2‐aminoanthracene, as measured in the Ames test (TA98), but there was a notable reduction following more than 1 year of storage in the ability of the S‐9 to generate Ames test activity with benzo(a)pyrene. Based on the results of these studies, S‐9 prepared and stored under these conditions appears to be suitable for use in in vitro genotoxicity assays for at least 1 year.
A comparison of the acute toxicity of chemicals to fish, rats and mice
Authors: Hodson Peter V. 
Published: October 2006

AbstractThe acute toxicity of chemicals to rainbow trout, as shown by intraperitoneal injections (IP LD50), oral dosing (oral LD50) and aqueous exposure (LC50) was compared with published values for IP LD50s and oral LD50s of mice and rats. The method of comparison was by simple linear regression analyses of log‐transformed data, modified to recognize that X (fish toxicity) was neither fixed nor measured without error.Within‐species comparisons demonstrated very strong linear correlations (r =0.866–0.998) between IP and oral LD50s. Variability was least for the fish data since it was all generated in one laboratory.Comparisons between species of IP and oral LD50S gave correlation coefficients ranging from 0.59 to 0.95 with the majority over 0.80. Correlations were best (r =0.83–0.94) between fish LD50s and rat and mice IP LD50s. Correlations were poorest between fish and mammalian oral LD50s (r =0.59–0.66) because the sample sizes and the ranges of values were very small. In all cases, the slopes were close to, or equalled, 1.0.Comparisons of fish LC50s to fish or mammalian LD50s were not as successful. Correlation coefficients ranged from 0.19 to 0.83. Presumably the cause was the aqueous exposure. Interactions of the chemicals with water (e.g. dissociation) and with lipid membranes (partitioning) should cause considerable variations in uptake efficiency. However, adjustments of LC50s for dissociation constants and partition coefficients did not improve these correlations, probably because there were few chemicals for which all data were available.These comparisons demonstrate a potential for a wider use of surrogate species in toxicity testing and for adapting existing data from mammalian toxicology to aquatic hazard assessments.
Detection of teratogenic substances in acidic mine water samples using the frog embryo teratogenesis assay — Xenopus (FETAX)
Authors: Dawson Douglas A. , McCormick Curt A. , Bantle John A. 
Published: October 2006

AbstractThe FETAX (Frog Embryo Teratogenesis Assay — Xenopus) whole embryo bioassay has been developed to screen for environmental substances that cause birth defects. We have used this assay to test its effectiveness in working with actual water samples from the field. Tar Creek is contaminated by discharges from abandoned lead and zinc mines. In addition to high concentrations of zinc, iron and other metals, water samples are routinely low in pH and oxygen content. The pH values of three Tar Creek sample sites were below the established tolerance limits of the embryos. Therefore, one group of samples had no pH adjustment while a second group had the pH adjusted to 7.0. Two of the four sites contained agents that reduced embryonic growth and caused high rates of mortality. A third site contained teratogenic substances. We have determined that metal content is responsible, along with the low pH, for the biologic effects. We have identified high concentrations of toxic metals in Tar Creek by water analysis and were able to demonstrate, by removing metals via Chelex® 100 ion exchange chromatography, that the observed toxicity and teratogenicity were caused by metal ions.We have concluded that FETAX is an excellent test for complex mixtures. Physicochemical parameters, such as pH, oxygen and metals content, can be altered and the effect of these changes on toxicity and teratogenicity determined using FETAX. The interaction of toxic substances and low pH are important when considering embryo survival and development.
Potential uses of sea urchin embryos for identifying toxic chemicals: Description of a bioassay incorporating cytologic, cytogenetic and embryologic endpoints
Authors: Hose Jo Ellen 
Published: October 2006

AbstractA method for evaluating pollutant genotoxicity, embryotoxicity and teratogenicity using sea urchin embryos has been developed and was tested using benzo (α) pyrene (BP). Initial results suggested that the bioassay may be a sensitive indicator of pollutant toxicity and mutagenicity since several endpoints can be simultaneously assessed. The bioassay is rapid, inexpensive and appears applicable to a variety of toxicants and delivery methods. The test is based upon the standard 48 h sea urchin development assay and incorporates cytologic–cytogenetic analysis of embryos. Following toxic exposure of gametes, fertilization success is assessed. Embryos then develop for 48 h at which time survival and teratogenesis are evaluated. A subsample of embryos is stained and dissociated into monolayers and mitotic configurations are examined using light microscopy. Embryo mitotic rates are used as an indicator of overall embryonic health. Cytotoxic effects are concomitantly evaluated. Genotoxicity is measured using two methods: (1) anaphase aberration analysis, a technique which assesses abnormalities in the chromosome configurations (such as bridges and fragments) as the groups of chromosomes move to opposite poles and (2) micronucleus formation, a procedure examining the incidence of smaller, secondary nuclei composed of whole chromosomes or chromatid fragments. These two measurements preclude the need to examine individual chromosomes for deletions and exchanges, a laborious process in most aquatic organisms which possess numerous relatively small chromosomes.This genotoxicity–teratogenicity test appears promising for laboratory evaluations of individual substances or of complex chemical mixtures as weii as for environmental monitoring of nearshore areas. The standard development assay has been used to screen pharmaceuticals and environmental contaminants and some recent investigations have included mitotic aberration analysis. Experiments in our laboratory suggest that the genotoxicity–teratogenicity test may be a feasible approach to field monitoring. Mutagen loads of spawning adult urchins could be assessed by conducting cytologic–cytogenetic analysis of resulting embryos although initial studies suggest that this method is less sensitive than direct embryo exposures.
Similar profile of urinary and faecal metabolites of 14C‐carmoisine in male and pregnant female rats after oral administration
Authors: Tragni E. , Flaminio L. M. , Galli Corrado L. , Marinovich M. 
Published: October 2006

AbstractPregnant rats received 14C‐Carmoisine (200 mg kg−1; 25 μCi) by gavage on days 16–19 of gestation. The animals were killed and maternal tissues, amniotic fluid, placentae, foetal membranes and foetuses were analyzed for radioactivity. No evidence for the transplacental transfer of 14C‐Carmoisine or its metabolites was obtained. Male rats were given a single oral administration of 14C‐Carmoisine (200 mg kg−1; 25 μCi) and killed at different times after dosing. In both male and female animals, more than 90% of the radioactivity was excreted in faces and urine within 64 h, and the results suggested that there was no significant absorption of the azodye and no preferential concentration of the red food colour or its metabolites in any particular tissue. Analyses by HPLC, combined with a radioactivity monitor (RAM), of urine and faces of such animals show that five radioactive peaks were present in the radiochromatogram in addition to unmodified Carmoisine. The mean peak shows the retention time and the u.v. spectrum of authentic naphthionic acid. The results demonstrate that the pregnancy does not affect the kinetic and the metabolic profile of a single oral administration of the azodye Carmoisine given at different days of gestation.
A comparison of two bioassays used to estimate the toxicity of lupin material infected with Phomopsis leptostromiformis
Authors: Allen J. G. , Petterson D. S. , Ellis Z. 
Published: October 2006

AbstractEighty‐four lupin samples were tested for toxicity using two currently available bioassays. One utilizes sheep and the other nursling rats. There was an association between the results obtained by the two bioassays but 65% of the variance of the nursling rat bioassay results was not associated with the sheep bioassay results in the linear regression. Reasons for this poor correlation are suggested and discussed.
Pulmonary function responses in cats following long‐term exposure to diesel exhaust
Authors: Moorman William J. , Clark John C. , Pepelko William E. , Mattox Joan 
Published: October 2006

AbstractLong‐term inhalation studies were carried out to evaluate the toxic pulmonary effects of diesel engine emissions. Cats were exposed for over 2 years to whole, diluted diesel exhaust at levels expected to produce frank toxic effects. During the first 61 weeks of exposure, the cats received exhaust having a particulate level of 6 mg m−3. This was followed by a doubling of the exposure level from weeks 62 to 124 resulting in particulate levels of 12 mg m−3. No definitive pattern of pulmonary function response was observed following 61 weeks; however, a classic pattern of restrictive lung disease was found at 124 weeks. The significantly reduced lung volumes and diffusing capacity were indicative of a pulmonary interstitial response which was later verified by histopathology.