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Biomedical subjects

C Herr

Publications and source records attributed to C Herr.

16 recordsLinked to original sources
PubMed2005

Electromagnetic hypersensitivity (EHS) and subjective health complaints associated with electromagnetic fields of mobile phone communication--a literature review published between 2000 and 2004.

Literature published between 2000 to 2004 concerning electromagnetic fields (EMF) of mobile communication and electromagnetic hypersensitivity (EHS) or unspecific symptoms of ill health, respectively, is reviewed. Basically, literature from established databases was systematically searched for. For each study, the design and quality were evaluated by means of a criteria list in order to judge evidence for causality of exposures on effects. Finally, 13 studies of sufficient quality were considered for this review. In only one provocation study, individuals with self-reported electromagnetic hypersensitivity were exposed to EMF. Their perception of field status was no better than would have been expected by chance. Results of five randomised cross-over studies on impaired well-being due to mobile phone exposure were contradictory. Even though these studies would allow more reliable exposure assessment, they are limited due to short exposure period and the small study size. No firm conclusion could be drawn from a few observational epidemiological studies finding a positive association between exposure and unspecific symptoms of ill health due to methodological limitations. Causality of exposure and effect was not derivable from these cross-sectional studies as field status and health complaints were assessed at the same time. In addition, exposure assessment has not been validated. In conclusion, based on the limited studies available, there is no valid evidence for an association between impaired well-being and exposure to mobile phone radiation presently. However, the limited quantity and quality of research in this area do not allow to exclude long-term health effects definitely.

Anxiety↗
PubMed2001

Annexin VII: an astroglial protein exhibiting a Ca2+-dependent subcellular distribution.

A fundamental issue in neuronal and glial cells is how intracellular rises in Ca2+ are coupled to signaling cascades and changes in subcellular morphology. We studied the expression and localization of annexin VII (synexin), a Ca(2+)-/GTP-dependent membrane fusion protein, in the human CNS. Here, we demonstrate the presence of two annexin VII isoforms (47 and 51 kDa) in human brain tissue as well as its exclusive expression in astroglial cells. An in vitro study of astrocyte-derived C6 rat glioblastoma cells expressing a GFP tagged annexin VII fusion protein demonstrates a sequential redistribution of the fusion protein in response to rising intracellular Ca2+ concentrations. Our findings indicate a role of annexin VII in the regulation of intracellular Ca(2+)-dependent processes in astroglial cells.

Animals↗
PubMed2001

Loss of annexin A7 leads to alterations in frequency-induced shortening of isolated murine cardiomyocytes.

Annexin A7 has been proposed to function in the fusion of vesicles, acting as a Ca(2+) channel and as Ca(2+)-activated GTPase, thus inducing Ca(2+)/GTP-dependent secretory events. To understand the function of annexin A7, we have performed targeted disruption of the Anxa7 gene in mice. Matings between heterozygous mice produced offspring showing a normal Mendelian pattern of inheritance, indicating that the loss of annexin A7 did not interfere with viability in utero. Mice lacking annexin A7 showed no obvious phenotype and were fertile. To assay for exocytosis, insulin secretion from isolated islets of Langerhans was examined. Ca(2+)-induced and cyclic AMP-mediated potentiation of insulin secretion was unchanged in the absence of annexin A7, suggesting that it is not directly implicated in vesicle fusion. Ca(2+) regulation studied in isolated cardiomyocytes, showed that while cells from early embryos displayed intact Ca(2+) homeostasis and expressed all of the components required for excitation-contraction coupling, cardiomyocytes from adult Anxa7(-/-) mice exhibited an altered cell shortening-frequency relationship when stimulated with high frequencies. This suggests a function for annexin A7 in electromechanical coupling, probably through Ca(2+) homoeostasis.

Animals↗
PubMed1999

Pest control in public institutions.

After the spraying of insecticides against cockroaches in a kindergarten insecticide residues were detected over several months in spite of extensive decontamination. This prompted measurements in a home for asylum seekers, where insect pests had been controlled regularly by a commercial firm; here the presence of various biocides was demonstrated. As the insecticides could not be sufficiently decontaminated, the further administration was discontinued and instead cockroach traps and baits were set up. This alternative method which was well accepted by the inhabitants of the home as well as the administrative staff was subsequently successfully employed in other public institutions, e.g. a school and another kindergarten.

Animals↗
PubMed1999

[Effect of microbial aerosols on the human].

Based on numerous publications dealing with the effects of microbial emissions on workers in waste processing plants and on few papers concerning the assessment of the environmental health relevance of microbial aerosols on people living in the vicinity of composting facilities, the current state of the art in this field is presented. With regard to occupational exposure the possible health effects like infections, toxicity and allergies are specified. Since to date only few studies have been made of populations exposed to microbial aerosols in ambient air, the environmental health aspects are reviewed in the context of a study of three compost plants in Hesse, where ambient air measurements as well as epidemiological investigations were carried out. Final recommendations are given and the research needs regarding the environmental health significance of microbial aerosols are formulated.

Air Microbiology↗
PubMed1999

[Measuring the spread of airborne microorganisms in the area of composting sites].

Emission concentrations of culturable microorganisms were determined in the vicinity of three open or partly encapsulated composting facilities. Sampling was performed during so-called worst case situations which should promote aerial transport of emissions. Suitability of thermophilic organisms to detect an emitting influence of the plant was confirmed. Generally, concentrations decreased significantly with increasing distances from the plant at all three locations. At one plant 10(6) CFU m-3 thermophilic actinomycetes were found in a distance of 200 m. Partly increased concentrations could be determined even in distances above 500 m. Concentrations could vary within one hour to more than ten times.

Actinomycetales↗
PubMed1998

[Environmental-medical diagnosis and therapy. Hasty diagnosis of unspecified environmental syndromes should be avoided].

In the past ten years environmental medicine has virtually exploded. Major instruments for the interdisciplinary environmental-medical diagnosis are history, on-site inspection, biomonitoring and ambient monitoring. Since the definitive diagnosis of an environment-related disease usually requires a joint evaluation of toxicological, somatic and psychosomatic findings, it is recommended that cooperation with an experienced center for environment medicine should be established early on. By doing so, an inappropriate diagnosis of unspecific environment-medical symptom complexes such as, e.g., multiple chemical sensitivity may be avoided. Such "diagnoses" may result in drastic, and for the patient and his family, often stressful, consequences.

Decision Making↗
PubMed1993

DNA contamination of reagents used in embryo transfer and culture.

Commonly used reagents in the culture and transfer of embryos are isolated from blood and tissue samples and thus have the potential for chromosomal and or mitochondrial DNA contamination. In this study, we evaluated the results obtained from PCR analysis of bovine trypsin, bovine sera, and bovine albumin precipitates. Bovine sera samples that were tested yielded minor to heavy DNA contamination signals depending on the manufacturer and specific type of sera. Bovine albumin precipitates showed very little DNA contamination or none at all. Bovine trypsin samples yielded moderate DNA contamination signals depending on the ability of the trypsin to be inactivated prior to PCR analysis.

Journal Article↗
PubMed1981

Mutagenicity of fly ash particles in Paramecium.

Paramecium, a protozoan that ingests nonnutritive particulate matter, was used to determine the mutagenicity of fly ash. Heat treatment inactivated mutagens that require metabolic conversion to their active form but did not destroy all mutagenicity. Extraction of particles with hydrochloric acid, but not dimethyl sulfoxide, removed detectable mutagenic activity.

Animals↗
PubMed1981

Mutagenicity of coal fly ash: a new bioassay for mutagenic potential in a particle feeding ciliate.

The use of the established mutagenesis assay in Paramecium as a prescreen for hazardous environmental particles is described. Since these protozoans ingest particles of the size respired by animals and man, the biological effects of the respirable fraction of fly ash particles were monitored in particle-feeding eukaryotic cells. Fly ash from coal combustion was utilized for these studies and was found to be mutagenic. The effects of physical and chemical treatment of the particle mutagenicity provided evidence for both heat-stable, heat-labile and acid extractable mutagenic agents.

Animals↗