Search PubMed⌕ Search

Biomedical subjects

G Voigt

Publications and source records attributed to G Voigt.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparative feline genomics: a BAC/PAC contig map of the major histocompatibility complex class II region.

The genome organization of the human major histocompatibility complex (MHC) will be best understood in a comparative evolutionary context. We describe here the construction of a physical map for the feline MHC. A large-insert domestic cat genomic DNA library was developed using a P1 artificial chromosome (PAC) with a genomic representation of 2.5x and an average insert size of 80 kb. A sequence-ready 660-kb bacterial artificial chromosome/PAC contig map of the domestic cat MHC class II region was constructed with a gene order similar to, but distinct from, that of human and mice: DPB/DPA, Ring3, DMB, TAP1, DOB, DRB2, DRA3, DRB1, DRA2, and DRA1. Fluorescence in situ hybridization analyses of selected class II PAC clones confirmed that the class II region lies in the pericentromeric region of cat chromosome B2. However, apparently unlike the human and mouse MHCs, the domestic cat DRA and DRB genes have undergone multiple duplications and the DQ region has been deleted.

Animals↗
PubMed2001

Temporal and spatial prediction of radiocaesium transfer to food products.

A recently developed semi-mechanistic temporal model is used to predict food product radiocaesium activity concentrations using soil characteristics available from spatial soil databases (exchangeable K, pH, percentage clay and percentage organic matter content). A raster database of soil characteristics, radiocaesium deposition, and crop production data has been developed for England and Wales and used to predict the spatial and temporal pattern of food product radiocaesium activity concentrations (Bq/kg). By combining these predictions with spatial data for agricultural production, an area's output of radiocaesium can also be estimated, we term this flux (Bq/year per unit area). Model predictions have been compared to observed data for radiocaesium contamination of cow milk in regions of England and Wales which received relatively high levels of fallout from the 1986 Chernobyl accident (Gwynedd and Cumbria). The model accounts for 56% and 80% of the observed variation in cow milk activity concentration for Gwynedd and Cumbria, respectively. Illustrative spatial results are presented and suggest that in terms of food product contamination areas in the North and West of England and Wales are those most vulnerable to radiocaesium deposition. When vulnerability is assessed using flux the spatial pattern is more complex and depends upon food product.

Cesium Radioisotopes↗
PubMed2001

Countermeasures for animal products: a review of effectiveness and potential usefulness after an accident.

Over the last decade, there has been considerable progress in the development of countermeasures for preventing or reducing contamination of animal products by radioisotopes of iodine, caesium and strontium. In this paper, recent significant technical improvements are summarised and the current availability of countermeasures and their usefulness in the event of a nuclear accident reviewed. An improved understanding of factors controlling the metabolism of radioiodine and radiostrontium has enabled previously suggested countermeasures to be either optimised or dismissed. For radiocaesium in particular, experience since the Chernobyl accident has enabled effective and feasible countermeasures to be identified and successfully implemented in different situations. It has also been more widely understood that countermeasure effectiveness, although important, is not the only criterion which needs to be determined. In addition, cost and practical considerations such as availability, technical feasibility, acceptability and side-effects need to be taken into account. Evaluation of these factors has shown that some previously recommended countermeasures are unlikely to be feasible.

Agriculture↗
PubMed2001

Self-help countermeasure strategies for populations living within contaminated areas of Belarus, Russia and Ukraine.

Countermeasures have been effectively employed within intensive agricultural systems in areas of the Former Soviet Union (FSU) affected by the Chernobyl accident. However, ingestion doses continue to be elevated in some areas as a result of few foodstuffs which are collected from the wild or produced by the household. Forest fungi and berries, and milk from privately owned cattle are the most notable contributors to 137Cs intakes amongst these foodstuffs. In this paper we consider advice which would help affected populations to both understand the importance of these exposure routes and to reduce their exposure. In addition to the potential radiological benefits, self-help schemes are highly cost-effective and likely to have a positive psychological influence on populations living within contaminated areas of the FSU. Evidence to suggest that the transfer of radiocaesium to cow milk is considerably higher in the FSU than within western Europe and North America is discussed.

Agriculture↗
PubMed2000

Quality control of automotive engine oils with mass-sensitive chemical sensors--QCMs and molecularly imprinted polymers.

Molecularly imprinted polyurethanes were used as sensor materials for monitoring the degradation of automotive engine oils. Imprinting with characteristic oils permits the analysis of these complex mixtures without accurately knowing their composition. Mass-sensitive quartz crystal microbalances (QCMs) coated with such layers exhibit mass effects in addition to frequency shifts caused by viscosity, which can be compensated by an uncoated quartz or a non-imprint layer. Incorporation of degradation products into the imprinted coatings is a bulk phenomenon, which is proven by variation of the sensor layer height. Therefore, the resulting sensor effects are determined by the degradation products in the oil.

Journal Article↗
PubMed2000

Analysis of the contribution of forest pathways to the radiation exposure of different population groups in the Bryansk region of Russia.

The experience gained in the aftermath of serious radiation accidents shows that forests are an important source of external and internal exposure of the affected population. This paper presents the results of an assessment of the major radiological consequences for forests of Russia, most heavily contaminated after the Chernobyl nuclear power plant (ChNPP) accident. Illustrated in the Novozybkovsky district of the Russian Federation, the significance of different forest exposure pathways is estimated and the doses resulting from forest pathways are compared with the doses from agricultural products. It has been found that the contribution of mushrooms and berries to the internal doses of the population, relative to the doses from agricultural products, varied from 10-15% in 1987 to 40-45% in 1996. The results indicate large differences in internal exposure of members of the "critical groups" and "normal population", increasing with time after deposition. Data are presented that give information on the contribution of forests to the collective doses of inhabitants of the area under consideration. It has been shown that for 10 years after the accident (1987-1996), the contribution of forest products to the collective dose of the rural population living in contaminated forests of the Novozybkovsky district, amounts to about 20% (213 person Sv) of the total collective dose of internal and external exposures. However, a potential impact of these products including the dose from exported products is much higher and might reach 659 person Sv. It has been found that in the long-term after the ChNPP accident, serious attention should be given to forest countermeasures, and restoration strategies should be selected on the basis of a combined analysis of the effectiveness of forest and agricultural countermeasures.

Agaricales↗
PubMed1999

Radioactive contamination: state of the science and its application to predictive models.

Information on environmental levels and transport processes of natural and anthropogenic radioactivity, although plentiful, is widely scattered, and relatively few attempts have been made to summarize and synthesize this information. Furthermore, most experimental observations and experiments on environmental radioactivity have been designed for documentation or testing of specific hypotheses, rather than for providing key information for transport simulation models or on fundamental processes which such models seek to represent. This paper examines three basic questions, namely (1) what is the current state of the science of radioecology?; (2) how well is this science being incorporated into predictive models?; and (3) how well are the models being used to guide and improve the science? These discussions will be preceded by a brief description of the field of radioecology, and comments on its relevance to other sciences as well as to major societal problems stemming from environmental releases of radioactivity. In addition to assessing the current state of the science and its use in predictive models, specific ideas for improving both the science and its associated models will be advanced. These ideas fall under the categories of (1) environmental transport processes and model parameters, (2) estimating exposure and dose to human and ecological receptors, and (3) dose-effect relationships for plants and animals.

Journal Article↗
PubMed1998

[Marking of horses].

The author informs on up to date identification methods of horses. The implantation of passive transponders is a practicable method for marking of horses. Because it gives less pain to horses, this method is to prefer. Stress inflicted on horse is minimal, it compares to a intramuscular injection. The reliability of the system in use has so far been very high. Members of ISO have voted overwhelmingly in favor of a standard for electronic identification of animals. From now on, countries and user organizations can make use of this technique to identify animals and if used can rely on the fact that their animals can be uniquely identified all over the world.

Animal Identification Systems↗
PubMed1997

Thyroid dose reconstruction for the population of Belarus after the Chernobyl accident.

An 131I environment transfer model--adapted for Belorussian conditions--was applied to estimate thyroid doses for different population groups. For this purpose the available data were analysed and the important radioecological parameters assessed i.e. (a) the elimination rate of 131I from grass due to weathering and growth dilution, (b) the initial interception of 131I by vegetation, (c) the transfer coefficient for 131I from grass to cow's milk, (d) the yield to pasture grass and (e) the milk consumption rate. Additionally, the influence of applied countermeasures has been taken into account, such as the interruption of locally produced milk consumption, and the appropriate correction factors have been estimated. As a result, the average age-dependent thyroid doses were assessed for the Belorussian population. The highest average doses in children (> 1 Gy) have been estimated for the Bragin, Khoiniki, Narovlia and Vetka raions of the Gomel oblast. The thyroid exposure tends to decrease from the southeastern (closest to the Chernobyl nuclear power plant areas) to the northwestern part of the republic. When comparing the assessed thyroid doses with estimates derived from direct 131I activity measurements in thyroids (for the locations with more than 15 direct measurements), the results agree fairly well. The model calculation may perhaps overestimate thyroid doses of the population residing in the settlements of the central and northern parts of Belarus, distant from the areas with direct measurements of 131I activities in soil, grass and milk. These thyroid dose estimates may serve as a basis for further epidemiological studies and risk analyses.

Adolescent↗
PubMed1997

The transfer of 137Cs from barley to beer.

Beer has been brewed from barley contaminated with 137Cs as a consequence of the Chernobyl accident. The 137Cs activity has been measured in all intermediate steps and in the by-products of the production process. About 35% of the 137Cs in barley were recovered in beer. Processing factors defined as the concentration ratio of processed and raw products were determined to be 0.61, 3.3, 0.1 and 0.11 for malt, malt germs, spent grains and beer, respectively.

Beer↗
PubMed1997

Health impacts of large releases of radionuclides. Physical transport and chemical and biological processes in agricultural systems.

The purpose of radioecological models is to make realistic estimates of doses to the public after accidental releases of radionuclides into the environment. Important physical, chemical and biological processes involved in the dispersion and transport of radioactive substances in the atmosphere and along the food-chains are presented. The results of the EURAD (EURopean Acid Deposition) model, predicting the deposition patterns of 131I and 137Cs in Belarus and Ukraine after the Chernobyl accident, are discussed. An overview of the most important ecological processes--such as deposition, interception and translocation, weathering, transfers from soil to plants and from plants to animal/animal products, and seasonality in agricultural environments--is given. Examples corresponding to these individual processes, mainly experimental results after the Chernobyl accident and related to radiocaesium and radioiodine, are shown and discussed.

Agriculture↗
PubMed1996

Scientific recommendations for the reconstruction of radiation doses due to the reactor accident at Chernobyl.

In the years after the Chernobyl reactor accident, many studies of the radiation exposure levels and resulting health effects in the countries of the CIS have been conducted. The increasing incidence of childhood thyroid cancers in Belarus and Ukraine has stimulated worldwide multi- and bilateral cooperations with those countries and Russia in order to optimize benefits for those directly affected, but also to enlarge current knowledge of the consequences of reactor accidents. An international workshop on dose reconstruction was held in Bad Honnef, June 6 to 9, 1994, to address the problems which arise in dose reconstruction. The main objectives of this workshop were to bring together the best professional expertise and scientific knowledge and to achieve a better, multi-disciplinary harmonisation of the different scientific approaches. After intensive discussions the participants of this workshop formulated the following scientific recommendations for radiation dose reconstruction.

Body Burden↗
PubMed1996

Coronary heart disease mortality, morbidity, and case fatality in five east and west German cities 1985-1989. Acute Myocardial Infarction Register Teams of Augsburg, Bremen, Chemnitz, Erfurt, and Zwickau.

Cardiovascular mortality (CVD; International Classification of Diseases [ICD] 390-458) is higher in East than in West Germany, but the differences in official coronary heart disease mortality (CHD; ICD 410-414) are not so pronounced. The aim of this study was to validate the official mortality statistics based on the five German AMI registers and to analyze whether these mortality differences are due to differences in the attack rates of acute myocardial infarction (AMI) or to differences in the 28-day case fatality rates. This comparison includes the MONICA study cities of Augsburg and Bremen, both in West Germany, as well as the cities of Chemnitz, Erfurt, and Zwickau in East Germany (former the German Democratic Republic). The rates were calculated on the basis of all MONICA cases of definite AMI or coronary death aged 35 to 64 years occurring in the respective study populations between 1985 and 1989. All study populations except women in Augsburg showed higher coronary death rates compared to the rates based on the official cause of death statistics (ICD 410-414), but this difference was significant only for men in Chemnitz. In men there were no significant differences in the register-based coronary death rates between these urban areas (160/100,000 in Zwickau to 170/100,000 in Chemnitz) nor in the AMI attack rates (327/100,000 in Augsburg to 363/100,000 in Chemnitz), and consequently no significant center differences in the overall 28-day case fatality. However, the prehospital case fatality was significantly higher in Erfurt (34%) than in Bremen (27%). There were no significant differences in the AMI attack rates in women as well (60/100,000 in Chemnitz to 70/100,000 in Bremen and Erfurt), but the overall 28-day case fatality showed a clear gradient from the East (61-71%) to the West German cities (48-56%) and therefore also the register-based coronary death rates (38-50/100,000 and 34-38/100,000, respectively). However, the higher 28-day case fatality in women found in the MONICA registers in East compared to West Germany is not reflected in the CHD mortality statistics because of a stronger underestimation of the official mortality rates and in East than in West Germany, in particular in women. Nevertheless, the total mortality rates and in most cases also the CVD mortality rates were in women significantly higher in the East German compared to the West German cities. The East German official preunification CHD mortality data cannot be used for national and international comparisons. The results of the MONICA AMI registers in East and West Germany indicate, furthermore, the need to improve coronary care in women in the eastern part of the country. Nevertheless, because of the relatively high AMI attack rate in both parts of Germany primary prevention must generally be intensified.

Adult↗