Expression of atopic criteria in a population of medical nurses and hairdressers at the beginning of vocational training.
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Adolescent↗
Biomedical subjects
R Bartsch
Publications and source records attributed to R Bartsch.
The potent free radical scavenger alpha-lipoic acid improves cognition in rodents.
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Aging↗
[Experiences with high-frequency hearing tests in the selection of personnel for noise occupations].
A total of 181 persons aged between 16 and 18 were checked fully audiometrically (conventional and high-frequency audiogram). Dates of history about hereditary hearing damage, own ear diseases, noise exposure during frequent visits to discothecs or usage of Walkman etc. were ascertained by questionnaires. The evaluation of the results was carried out with the help of discrimination analysis allowing a multi-dimensional classification. As a result there could be made a sure discrimination analytic separation in persons with ear diseases during their childhood, when the high frequencies from 10 to 15 kHz were taken in. Thus the damage of the inner ear was to be found mainly on the base of the cochlea. Also in cases of hereditary influence there was to be seen a clear deminution in the high frequency area. The group of persons, who regularly went to discos (more than three times a month) as well as the group often using Walkman revealed a sure separation, when the high frequencies above 8 kHz were considered in the calculation. Altogether there could be seen an early damage more clearly in the high frequency area after ear diseases in childhood as well as a result of sound overloading than in conventional hearing area.
Adolescent↗
Quantitation of Cu-containing metallothionein by a Cd-saturation method.
A rapid and sensitive method for determining Cu-containing metallothionein (MT) is described. The main features of this Cd-saturation assay are: high-molecular-weight Cd-binding compounds are denatured with acetonitrile (50% final concentration), Cu bound to MT is removed with ammonium tetrathiomolybdate, excessive tetrathiomolybdate and its Cu complexes are removed with DEAE-Sephacel, apothionein is saturated with Cd, and excessive Cd is bound to Chelex 100. The thiomolybdate assay is capable of reliably detecting 14 ng MT and thus is particularly suitable for measuring MT in small tissue samples (e.g., biopsies), in extrahepatic tissues, and in cultured cells. Moreover, the combination of the thiomolybdate assay with the recently developed Cd-Chelex assay also makes it possible to determine the portion of MT which binds Cu (Cu load of MT), provided that the amount of non-Cu-thionein exceeds 100 ng, the detection limit of the Cd-Chelex assay.
Animals↗
The Cd-Chelex assay: a new sensitive method to determine metallothionein containing zinc and cadmium.
A rapid and sensitive one-vial procedure to determine metallothionein (MT) containing zinc (Zn) and cadmium (Cd) is described. New features of this Cd-saturation method are: high molecular weight Cd-binding proteins are denatured by treatment with acetonitrile (50% final concentration), and excess of Cd is bound to a cation exchange resin (Chelex-100). With this method, MT has been measured, e.g. in liver of control and zinc- or cadmium-treated rats, in human liver and in cultured human fibroblasts down to absolute amounts of 0.1 microgram. The Cd-Chelex assay is 10 times more sensitive than the established Cd-heme assay (Dieter et al. 1986) and therefore is particularly suitable to quantify MT in small tissue samples (e.g., liver biopsies of a few milligrams) and in extrahepatic tissues or cell cultures with low MT concentrations.
Adolescent↗
[The accuracy of subjective determination of auditory threshold in the range of 0.5 to 18.0 kHz using different sound transducer systems].
This paper reports on the degree of accuracy of determinations of hearing threshold in the 0.5 to 18 kHz range. As far as possible, these hearing thresholds were compared with those of ISO 389. Furthermore, the study compared determinations of hearing thresholds measured on different days. Reproducibility was very good, particularly of the high-frequency thresholds. The two types of sound transducers used here (a quasi-free field system developed by the authors and a pair of professional headphones) showed an identical transmission of frequencies and good reproducibility of the results of measurements.
Adult↗
High-frequency audiometry in the evaluation of critical noise intensity.
We investigated a total of 537 subjects (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the high-frequency (HF) range. The persons we tested work at three different noise-levels [80-84, 85-89, 90-94 dB (A), measured as leq). The differences in the hearing thresholds between this three groups mentioned were checked by means of discriminant analysis. The first hearing level changes at a noise-level below 90 dB (A) leq develop mainly in the HF range. In the conventional hearing range, however, the hearing levels remain unchanged even over long exposure times. Noise-induced hearing loss in the conventional range occurs only in the sound level group of 90 to 94 dB (A) leq without attaining any social importance. The tests show that, if the noise-level 90 dB (A) leq is not exceeded, no noise-induced hearing impairments involving social hearing loss are to be observed. Thus we assume that an auditory risk criterion of 85 dB (A) leq is sufficient to prevent hearing loss of any social importance.
Adult↗
Effects of carbamazepine, valproate calcium, clonazepam and piracetam on behavioral test methods for evaluation of memory-enhancing drugs.
The effect of three anticonvulsants on several test methods for evaluation of memory-enhancing drugs have been studied in rats and mice. The results were compared to the results obtained from the nootropic piracetam and from imipramine. In an active avoidance test (pole jumping), repeated administration of carbamazepine (5 mg/kg i.p.) and piracetam (300 mg/kg p.o.) protected against impairment of learning rate caused by repeated application of an electroconvulsive shock. Valproate calcium (repeated administration of 30 mg/kg i.p.) was only weakly active, while clonazepam (repeated administration of 0.3 mg/kg i.p.) decreased the learning rate even more. Drugs were given in dosages which have no anticonvulsive activity in this test. The impairment of learning rate caused by repeated application of ethanol was prevented by carbamazepine (5 mg/kg i.p.), valproate calcium (30 and 100 mg/kg i.p.) and piracetam (100 mg/kg i.p.). Clonazepam (0.3 and 1 mg/kg i.p.) had a worsening effect on learning rate. In Porsolt's behavioral despair test, carbamazepine (5, 10 and 30 mg/kg i.p.) and valproate calcium (30 and 100 mg/kg i.p.) shortened the duration of immobility, which indicates an increased psychomotor activity. Clonazepam was ineffective. Results obtained with carbamazepine are similar to those obtained with piracetam. The data are discussed in view of the so-called psychotropic effects of carbamazepine in clinical trials.
Animals↗
[Risk of nose cancer following occupational exposure to organic dusts].
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Adolescent↗
Antihypoxic effects of AWD 23-15 in mice and rats.
AWD 23-15 (6-Methyl-1,2,3,4-tetrahydro-pyrimidin-2,4 dion) which is known to improve learning and memory processes in laboratory animals, was investigated in several hypoxia models. The following results were obtained: 1. Increase of survival rate, 2. change in hypoxia-induced decrease of cerebral post-mortem adenylic energy charge and in concentrations of metabolic products in the brain and 3. antagonism of the hypoxia-induced decrease of dopamine release. However in the general behavioral test the drug was ineffective. These results support the idea that AWD 23-15 is a potential nootropic drug.
Adenine Nucleotides↗
[Wood dust concentrations in wood processing industries].
68 mean values of airborne shift concentration of total dust were measured at 9 factories of woodworking industries. The values varied from 0.18 to 59.3 mg/m3 for area sampling. But at 63% of the woodworking machines with exhaustion the area sampling shift concentration of total dust reached fewer values than 5 mg/m3. This is a significant decrease of dust concentration in the last ten years.
Air Pollutants, Occupational↗
AWD 52-39, an ergot derivative with potential nootropic activity.
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Animals↗
[High-frequency audiometry for the early diagnosis of occupational acoustic trauma].
We investigated a total of 537 patients (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the HF range. The persons tested work at 3 different noise levels (80-84, 85-89 and 90-94 dB [A] Leq). The differences in the hearing thresholds of the three sound level groups mentioned above were checked by means of discrimination analysis. The first hearing level changes noise levels below 90 dB develop mainly in the HF range; in the conventional hearing range, however, the hearing levels remain unchanged even during long exposure times. Hearing level impairment in the conventional range occurs only in the sound level group of 90-94 dB (A) Leq without attaining any social importance. The tests clearly show that if the noise level damage risk criterion of 85 dB (A) Leq at which hearing is impaired, is not exceeded any hearing lesions involving social hearing loss are definitely avoided.
Adult↗
[The effect of nootropics on impared learning performance in a pole jumping test after repeated ethanol administration].
The influence of ethanol administration (4 ml of 10% ethanol/d p.o.) for 6 and 13 d respectively, on learning behaviour of rats has been studied using an active avoidance reaction. While the formation of an active avoidance reaction was only insignificantly impaired by the application of ethanol for 6 d, the learning performance of rats showed a significant deficit after 13d of ethanol ingestion. Repeated nootropic pretreatment (d11 to 14 following first ethanol dose b.i.d.) resulted in an attenuation of learning deficits. The nootropics piracetam (100 mg/kg i.p.) methyl-glucamine orotate (225 mg/kg i.p.), meclofenoxate hydrochloride (100 mg/kg i.p.), pyritinol (100 mg/kg i.p.) and dihydroergotoxine mesilate (1 mg/kg i.p.) showed to be effective. The possible mechanism of action is discussed.
Animals↗
[Increased incidence of malignant tumors of the nose and nasal sinuses in workers in the wood industry and other occupations].
In the period of 1958-1979 in the files of National Cancer Register (NCR) of GDR 1,313 patients with nasal cancer (ICD 160) were registered in seven districts of the GDR. In collaboration with NCR the occupational history of 1,160 patients with nasal cancer was recorded by a questionnaire. The results suggest an increased number of tumors in several professions. Compared to about 19 expected tumors in male woodworkers the number of the observed was 70. This is a statistical significant risk of 3.6.
Female↗
Influence of different kinds of noise on the ear and some physiological and psychological parameters.
The reactions of the human organism to noise are complicated and difficult to separate from other stressors, with the exception of hearing damage. After thorough experimental planning and a rigorous selection of sample persons, the reaction to noise of varying structures was studied by reactions of heart rate, blood pressure, reaction time, the temporary threshold shift (TTS) of hearing and the psychological parameters "Mood" (in German "Befinden"). We found a special kind of TTS dependent on the structure o noise and no effect of physiological parameters. The psychological parameter tended to have a significant influence on individual factors.
Audiometry↗
[The problem of critical intensity].
We investigated a total of 537 patients (68 men, 469 women) working in the textile industry to ascertain their hearing level in the conventional hearing range as well as in the HF range. The persons tested work at 3 different noise levels (80-84, 85-89 and 90-94 dB (A) Leq. The differences in the hearing thresholds of the three sound level groups mentioned above were checked by means of discrimination analysis. The first hearing level changes noise levels below 90 dB develop mainly in the HF range; in the conventional hearing range, however, the hearing levels remain unchanged even during long exposure times. Hearing level impairment in the conventional range occurs only in the sound level group of 90-94 dB (A) Leq without attaining any social importance. The tests clearly show that if the noise level damage risk criterion of 85 dB (A) Leq at which hearing is impaired, is not exceeded any hearing lesions involving social hearing loss are definitely avoided.
Adolescent↗
Cellular targets for SV40 large T-antigen.
SV40 virus infection is able to induce tumours in newborn hamsters and to transform a wide range of eukaryotic cells in in vitro culture. This is achieved by integration of the viral DNA into the host cell DNA and expression of the virus-encoded Large T-antigen. The expression of Large T, a 708 amino acid phosphoprotein, is required both to induce and maintain the transformed state. The Large T protein initiates viral DNA synthesis and regulates viral transcription, apparently by binding in a specific manner to viral DNA sequences at and near the viral origin of replication. SV40 Large T also affects cellular DNA synthesis and transcription and this may account for its oncogenic activity. A novel immunochemical procedure has permitted the isolation of cellular DNA sequences occupied by SV40 Large T in the chromatin of SV40 transformed cells. Some of the cellular sequences contain high affinity binding sites for SV40 Large T, and hybridize to messenger RNAs expressed in SV40 transformed but not in normal cells. A second type of cellular target for Large T is the cell coded p53 protein that it binds to and stabilizes. A range of monoclonal antibodies to p53 has been isolated and characterized. They demonstrate that p53 is in the cytoplasm of normal cells but is located in the nucleus of transformed cells. One of the antibodies recognizes an epitope on p53 that is stabilized or induced by binding to Large T. Further studies on the T-p53 protein complex have been facilitated by constructing bacterial plasmids that direct the synthesis of substantial quantities of Large T-beta-galactosidase and p53-beta-galactosidase fusion proteins in bacteria. The results are discussed in the context of our current knowledge of oncogene action.
Animals↗