摘要:

AbstractGyromitra esculenta(Pers.: Fr.) Fr. and a few other mushrooms have caused severe poisonings and even deaths in humans. Clinical data are characterized primarily by vomiting and diarrhea, followed by jaundice, convulsions and coma. Gastrointestinal disorders distinguish this poisoning. Frequent consumption can cause hepatitis and neurological diseases.The species of concern are mainlyG. esculentaandG. gigas(Kromb.) Cooke (non Phill.). Nevertheless, recent advances in chromatography, biochemistry and toxicology have established that other Ascomycetes species also may prove toxic.Gyromitrin (acetaldehyde methylformylhydrazone, G) and its homologues are toxic compounds that convertin vivointoN‐methyl‐N‐formylhydrazine (MFH), and then intoN‐methylhydrazine (MH). The toxicity of these chemicals, which are chiefly hepatotoxic and even carcinogenic, has been established throughin vivoandin vitroexperiments using animals, cell cultures and biochemical systems. When we consider the chemical nature and the reactivity of these natural compounds, we suggest that chemical and biochemical mechanisms may explain their intrinsic biological a

ISSN:0260-437X    

DOI:10.1002/jat.2550110403

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe effects of mixtures of parathion (PA; 5 mg kg−1), toxaphene (TOX; 50 mg kg−1) and/or 2,4‐dichlorophenoxyacetic acid (2,4‐D; 50 mg kg−1) on the hepatic mixed‐function oxygenase (MFO) system were studied in ICR male mice (21–24 g) by oral intubation daily for 7 days. In general, TOX and TOX‐containing mixtures were found to induce the metabolism of amidopyrine (21–52%), aniline (58–72%), phenacetin (239–307%), pentobarbital (104–148%) and benzo[a]pyrene (143–304%) in the 9000 g liver supernatants and to increase the hepatic cytochrome P‐450 contents (57–80%). Furthermore, the TOX pretreatemnt was effective in enhancing the biotransformation of PA or paraoxon (PO) in the supernatants. This enhancement was not altered significantly by 5 mM EDTA. Although TOX increased the aliesterase activity in the serum and liver homogenates and supernatants by 31–158%, the activity of paraoxonase was not affected in these preparations. The TOX‐induced increase in the metabolism of PA or PO was, at least in part, associated with the MFO system, and paraoxonase did not have significant involvement in the increase. These findings suggest that the toxicity of the PA + TOX mixture would be lower than that of PA, as TOX has the ability to increase the biotransformation of PA, as well as of PO, and the levels of aliesterase, thereby providing a pool of non‐critical enzymes for the binding of PO. Because of these properties of TOX, it is anticipated that the toxicity of the PA + TOX + 2,4‐D mixtur

ISSN:0260-437X    

DOI:10.1002/jat.2550110404

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractMany aquatic bioassays rely on chemical solvents to solubilize water‐insoluble test materials. Interactions between solvents and test materials can lead to false positive or negative results. For this reason, tests for interactions between solvents and test materials were performed. The Frog Embryo Teratogenesis Assay–Xenopus(FETAX) was chosen because of its capacity to assess three different endpoints; mortality, malformation and embryo growth. Three solvents–dimethylsulfoxide (DMSO), acetone and triethylene glycol (TG)–were tested with two teratogens–methylmercury chloride (MMC) and trichloroethylene (TCE). DMSO potentiated the lethal effect of both teratogens but did not alter significantly the rate of malformation. Acetone increased the mortality for both teratogens, but only increased the MMC malformation greater than the additive effects. TG only increased the mortality and malformation with TCE. There were additive effects for growth for all solvents with the teratogens. The carrier solvents caused interactions even at their no‐observable‐effect concentration (NOEC). Therefore, the choice of carrier solvent should be made with caution. This study shows that different results can occur depending on the solvent used, and that a difference in one endpoint does not necessarily change the ot

ISSN:0260-437X    

DOI:10.1002/jat.2550110405

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe role of 1,2‐diacetylbenzene (1,2‐DAB) in the peripheral nerve toxicity of 1,2‐diethylbenzene (1,2‐DEB) was investigated in rats. Gas chromatography‐mass spectrometry identified 1,2‐DAB in the urine samples of rats given 165 mg kg−11,2‐DEB orally on four consecutive days. 1,2‐DAB shared not only the ability of 1,2‐DEB to cause bluish discoloration of skin, internal organs and urine, but unlike 1,2‐DEB it turned hair blue at the site of intraperitoneal injection.Intraperitoneal administration of 10 mg kg−1and 20 mg kg−11,2‐DAB to groups of 12 rats, 4 days a week for 11 and 6 weeks, caused a dose‐ and time‐dependent decrease in mean sensory and motor conduction velocities. Recovery in a 5‐week post‐exposure period was gradual but consistent. The effect of 1,2‐DAB on the amplitude of the sensory action potential was ambiguous.The findings support the hypothesis that the formation of 1,2‐diacetylbenzene derivatives cont

ISSN:0260-437X    

DOI:10.1002/jat.2550110406

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractA total of 606 organophosphate poisoning admission incidents were recorded and analysed retrospectively at the six central hospitals of Zimbabwe. The incidents covered a period of 10 years, i.e. from 1980 to 1989, inclusively. This accounted for 12% of all poisoning admission cases recorded at these hospitals and 84% of all pesticide poisoning cases. Of these organophosphate poisoning cases, 75% (450) were suicides and or parasuicides, 21% (126) were accidental, 2% (12) were homicides and 5% (30) were cases of an undetermined nature. The mortality rate was established at 8% (48). The study revealed that the 21–30‐year‐old age group is significantly more prone to poisoning (42% of the total) than other age groups.The mean period of hospitalization of an organophosphate‐poisoned patient was found to be 8 days (the range was 1–29 days). The mean cost of keeping a poisoned patient in hospital during that period was calculated at Z$450.00 (i.e. US$225), excluding the cost of treatment. The total number of hospitalization days was 1599 and the total cost of keeping the patients in hospital was therefore Z$89,943,75, i.e. Z$11, 242,96 per year. The most popular (utilized) first‐line treatment (22% of all patients) was a combination of ipecacuanha syrup plus atropine, with atropine alone a poor second (10% of treate

ISSN:0260-437X    

DOI:10.1002/jat.2550110407

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractIn the present study the influence of age and time of chelation therapy on cadmium retention in 6‐, 11‐and 14‐day‐old rats and in 6‐week‐old rats has been investigated. Chelating agentsN‐benzyl‐dithiocarboxy‐D‐glucamine (BDCG), sodiumN‐(metho‐xybenzyl)‐D‐glucamine dithiocarbamate monohydrate (MeOBDCG) andN‐methyl‐N‐dithiocarboxy‐D‐glucamine (MDCG) were administered intraperitoneally to three different groups at a dose of 1 mmol kg−1body weight on two occasions following115mCd intraperitoneal administration; immediately and after 24 h; after 24 h and 48 h; or after 48 h and 72 h. The115mCd retention in the whole body and organs was determined 6 days after cadmium administration. Chelation therapy very effectively reduced cadmium retention in the whole body and organs, MeOBDCG being the most effective. The effects of chelating agents were significantly more pronounced in older than younger animals and in the case of early rather than late administration. The highest fraction of cadmium administered was retained in the liver, where also the strongest effect of chelation therapy was observed. Mobilized cadmium was excrete

ISSN:0260-437X    

DOI:10.1002/jat.2550110408

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe uptake and biological transformation of Ni3S2was studied on guinea pig alveolar macrophages (GPAM) in primary culture. Two different pathways are observed: (i) phagocytosis of αNi3S2crystals and subsequent degradation to minute particles, which are recovered bound to the membranes of phagocytic vacuoles and to lysosomal membranes. These degradation products contain sulphur in very reduced quantities, as revealed by energy‐dispersive spectrometry (EDS). (ii) Extracellular degradation to regular round particles (0.1–0.2 μm) and irregular minute particles (10–30 nm). Round particles may enter the cell by pinocytosis and are characterized by the loss of sulphur. Minute particles are bound preferentially to cell membranes, to cytoplasmic organelles, such as endoplasmic reticulum, mitochondria and peroxysomes, to liposomes and to the euchromatinic part of nuclei. EDS analyses in these particles revealed the substitution of sulphur by phosphorus. This observation suggests the formation of an Ni–P complex with the phosphate groups of membranous and liposomal phospholipids and of the euchromatinic part of DNA or RNA. Steady‐state flourescence polarization analysis were carried out on GPAM and, for comparative purposes, on human embryonic pulmonary epithelial cells (L132 cell line). In both cell types they revealed a significant increase of membrane fluidity, induced either by desaturation of aliphatic chains or directly by the cleavage of fatty

ISSN:0260-437X    

DOI:10.1002/jat.2550110409

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractRats were given ethanol in drinking water for 8 months, followed by inhalation exposure (5 h daily) to 12.000 mg m−3xylene for 9 days. Combined exposure to xylene and ethanol induced the same changes in the haematological, biochemical and biophysical parameters of the erythrocyte membrane as those found previously in our experiment with toluene–ethanol. Macrocytosis, a decrease in sedimentation rate and erthrocyte packing difference, as well as decreased fluidity of the erythrocytes membrane in the middle zone of the lipid bilayer, were the most significant changes of exposure to ethanol and xyl

ISSN:0260-437X    

DOI:10.1002/jat.2550110410

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractDaily administration of soman for several days results in several alterations in the vascular neuroeffector system. To determine whether or not soman alters intracellular Ca2+uptake, the effects of acute exposure to soman or 7‐day administration of 5μg kg−1of soman on the capacity of microsomes and mitochondria from rabbit aortic vascular smooth muscle to take up45Ca2+were determined. Acute exposure to soman concentrations of 1–100 μM did not alter significantly (P>0.05)45Ca2+uptake by either microsomes or mitochondria. On the other hand, 7‐day soman administration markedly reduced (P<0.05)45Ca2+uptake by both microsomes and mitochondria. Thus, calcium uptake and intracellular calcium uptake‐dependent responses will be affected by repeated soman adm

ISSN:0260-437X    

DOI:10.1002/jat.2550110411

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractSprague‐Dawley rats were exposed to aerosols of one of three base stocks used to formulate lubricating oils. These stocks were a solvent‐refined oil (SRO), a hydrotreated and acid‐washed white oil (WTO) and a severely hydrotreated and hydrocracked oil (HBO). Exposures were for 6 h per day, 5 days per week for ca. 4 weeks. There were four groups of rats for each study (10 per sex per group). Aerosol concentrations were ca. 0, 50, 210 and 1000 mg m−3for each material; the mass median aerodynamic diameter was ca. 1 μm. Following the last exposure, all animals were sacrificed and necropsied. Samples were taken for serum chemistry, hematology, sperm morphology, weights of seven organs and histopathology on at least nine organs. Body weights and clinical signs were not affected by exposures. The only treatment‐related changes were in the lung and associated lymph nodes. Both the wet weight of the lung and the dry/wet weight ratio increased in a concentration‐related manner. Associated with the increased weight were accumulations of foamy alveolar macrophages, particularly in alveoli close to alveolar ducts. Mild infiltration by neutrophils was observed with WTO and SRO; thickened alveolar walls were noted with the highest concentration of HBO. These mild responses to exposures at very high concentrations indicate a low degree of toxicity for th

ISSN:0260-437X    

DOI:10.1002/jat.2550110412

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY