Publications by authors named "Heger W"

Background: Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted.

Methods: Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances.

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Di(2-ethylhexyl)phthalate (DEHP) is a general-purpose plasticizer for polyvinyl chloride (PVC) and has become a ubiquitous environmental contaminant. It is suspected to be an endocrine disrupting/modulating substance in humans. Children are of special concern due to their developmental state.

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Urine samples from the 2001/2002 pilot study for the German Environmental Survey on children (GerES IV) were analysed for concentrations of the primary DEHP metabolite MEHP (mono(2-ethylhexyl)phthalate) and two secondary DEHP metabolites SOH-MEHP (2-ethyl-5-hydroxy-hexylphthalate) and 5oxo-MEHP (2-ethyl-5-oxo-hexylphthalate). Urine samples had been taken from 254 children aged 3 to 14. In addition, DEHP was analysed in house dust samples.

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[Reference values for indoor room air: naphthalene].

Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz

July 2004

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In vitro susceptibility testing was performed on 66 strains of Listeria monocytogenes. Recently obtained clinical isolates from Austria, France, Norway and Switzerland and 17 reference strains from three type culture collections were tested against ampicillin, gentamicin, trimethoprim-sulfamethoxazole, ampicillin-sulbactam, meropenem, and first-, second-, third- and fourth-generation cephalosporins. All isolates were susceptible to ampicillin, gentamicin, and trimethoprim-sulfamethoxazole, ampicillin-sulbactam, and meropenem and more than 86% of the minimal inhibitory concentration E test values were within plus/minus one dilution step of the agar dilution test.

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The relation of acute to prolonged toxicity of existing and new chemicals and active ingredients of numerous pesticides in the aquatic environment have been compared with their physico-chemical properties. The data had been presented to the authorities in behalf of the pesticide registrations, the notification of new chemicals or research projects. The ecotoxicity ratios are expressed as acute to prolonged ratios (APR).

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The dose-response of the teratogenic potency of the thalidomide (Thd) derivative EM12 was evaluated in the common marmoset (Callithrix jacchus). The smallest daily dose found to be effective was 30 micrograms EM12/kg body wt. This is the lowest dose of a Thd derivative ever reported to induce severe skeletal abnormalities.

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The published knowledge on neurobiological, psychological, and ethological aspects of development in Callithrix jacchus is still limited. We have collected published and unpublished data from several Callithrix colonies and pooled information on criteria for developmental progress and maturation using a questionnaire sent to numerous experts in the field. The data suggest that developmental stages can be defined not only for the embryonic and fetal but also for the postnatal period.

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Direct in vivo labeling of erythrocytes with biotin is shown as a method for estimation of red cell survival as well as of enrichment of young or aged erythrocytes. Two succinimide esters (biotin-N-hydroxysuccinimide ester [BNHS], caproylamidobiotin-N-hydroxysuccinimide ester [C-BNHS] were used for biotin labeling of erythrocytes. With improved syntheses, pure BNHS (mp, 212 degrees-214 degrees C) and the spacered intermediate for C-BNHS, 6-(biotinylamide) hexanoate (mp, 225 degrees-226 degrees C) were obtained in an overall yield of 86%; the yield of C-BNHS (mp, 167 degrees-169 degrees C) was 68%.

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The pre- and postnatal development of monooxygenases in the liver and adrenal gland of marmoset monkeys (Callithrix jacchus) was investigated. Cytochrome P450 was detected in the fetal adrenal gland, but aldrin epoxidase, ethoxycoumarin O-deethylase, and ethoxyresorufin O-deethylase activities were below detection limits. Although fetal hepatic cytochrome P450 was not detected, low activities of aldrin epoxidase and ethoxycoumarin O-deethylase, but no ethoxyresorufin O-deethylase, could be detected in fetal liver.

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Arthropathia in juvenile animals is the most important toxic effect induced by quinolones. We conducted pharmacokinetic and morphological studies with ofloxacin on non-human primates (Callithrix jacchus, Marmosets) and rats. In the marmoset, electron microscopy and the application of immuno-morphological methods proved to be suitable for the detection of specific alterations in cartilage (e.

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The rate of metabolism as well as the metabolic profiles of the enantiomers and the racemate of 2-(2,6-dioxopiperidine-3-yl)-phthalimidine (EM 12), a teratogenic thalidomide analogue, have been investigated in vitro and in the marmoset monkey in vivo. The half-life of racemic EM 12 and of the two enantiomers in vitro (phosphate buffer pH 7.4, 37 degrees C) were all in the same range (12 h).

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Data are presented on the normal intra- and inter-litter variability of the embryonic stages in the common marmoset (Callithrix jacchus) on day 56 of pregnancy. The embryology of the marmoset is described with respect to the susceptible period for the teratogenic action of thalidomide.

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The response of pregnant marmosets (Callithrix jacchus) to the thalidomide derivative EM 12 was evaluated. EM 12 was selected for these studies because it is more active than thalidomide and is much more stable for hydrolysis. Skeletal gross structural abnormalities were observed when EM 12 was given to marmosets for 3-7 days during the period between days 49 and 60 post ovulation.

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The teratogenic potencies of the enantiomers of 2-(2,6-dioxopiperidine-3-yl)-phthalimidine ( = EM 12), a teratogenic thalidomide analogue, were investigated in Callithrix jacchus, a primate very sensitive to the teratogenic action of this thalidomide analogue. The results indicate that the S-(-)-form of EM 12 is clearly more teratogenic than the R-(+)-form. The interpretation of the studies designed to evaluate stereo-selective differences in the teratogenicity of the enantiomers becomes difficult, since both enantiomers racemise in vivo with appreciable rates (Schmahl et al.

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Hydroxypregnanolone is the most abundant progesterone metabolite in the urine of marmoset monkeys (Callithrix jacchus). The substance is excreted as conjugate. The concentration of this steroid may be monitored by high performance, thin layer chromatography and postchromatographic derivatization.

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The pattern of operation injuries of the arterial vessels which may occur during hip surgery is illustrated by this summary of our own cases. Injuries of the femoral vessels seem to be preventable if the Hohmann-retractor is carefully placed on the anterior margin of the acetabular rim under digital control. Furthermore drilling damage of the iliac vessel appears to be avoidable.

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In Callithrix jacchus the urinary excretion of hydroxypregnanolone (5 alpha-pregnane-3 alpha, 7 alpha-diol-20-one) shows a luteal rise during the ovulatory cycle. This progesterone metabolite can therefore be used as an indication of ovulation, implantation, and subsequently for the persistence of the pregnancy. The excretion can be monitored by high performance thin-layer chromatography (HPTLC) and postchromatographic derivatization after enzymatic hydrolysis of the conjugate.

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We applied qualitative cytochemical procedures to investigate and compare the distribution of 3 beta-hydroxysteroid dehydrogenases (HSDH) in pro- and diestrus ovaries of sexually mature marmosets (Callithrix jacchus) using dehydroepiandrosterone or etiocholane-3 beta-ol-17-one as the substrate. During proestrus dehydroepiandrosterone dehydrogenase (3 beta-5 alpha-HSDH) activity was found in the theca of tertiary follicles and in atretic granulosa cells. In granulosa cells at advanced stages of degeneration, HSDH activity was distinctly higher than in thecal cells.

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Four different methods for the demonstration of the coronary arterial vasculature are examined. Among the techniques studied corrosion casts (epoxid- and acrylic resin) permit the best qualitative and quantitative evaluation of superficial and deep arteries and arterioles. Down to the smallest infusible vessels of 15-25 mum there is practically no shrinkage.

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