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Biomedical subjects

V Bencko

Publications and source records attributed to V Bencko.

At least 19 recordsLinked to original sources
PubMed2005

[Relationship between the levels of toxic polychlorinated biphenyls in blood and follicular fluid of sterile women].

OBJECTIVE: The aim of this study was to confirm the possibility of detection of toxic polychlorinated biphenyls in blood and follicular fluid of infertile women undergoing IVF+ET program and determine the levels of some congeners. To confirm their cumulation in follicular fluid. DESIGN: Pilot study. SETTING: Department of Obstetrics and Gynecology, 1st Faculty of Medicine, Charles University and General Faculty Hospital, Prague, AXYS Varilab s.r.o., Vrané nad Vltavou, Institute of Hygieny and Epidemiology, 1st Faculty of Medicine Charles University and General Faculty Hospital, Prague, Euromise Centrum, Charles University, Prague. METHODS: We detected the level of polychlorinated biphenyls in blood and follicular fluid of infertile women undergoing IVF+ET program. We recieved the follicular fluid by transvaginal punction of follicles under ultrasonography control. The blood was taken before begining of anestezia. The follicular fluid and blood were frozen and transported to the laboratory. The samples were examined there by methods of gas chromatography and mass spectrometry. We were able to find all PCBs with 3-7 atoms of chlorine. RESULTS: We confirmed the possibility of detection of polychlorinated biphenyls (PCBs) in blood and follicular fluid of infertile women. We examineted the levels of PCB 77, 81, 105, 114, 118+123, 126, 156, 157, 167, 169, 189. The levels of PCBs were in ng/gram of fat. The levels of polychlorinated biphenyls differed from 0 to 400 ng/g of fat. Statistical analysis was made by t test a Wilcox test. All PCBs are cumulated in follicular fluid, except of PCB 126. CONCLUSION: The possibility of detection of PCBs in blood and follicular fluid of infertile women undergoing IVF+ET program was confirmed. The cumulation of these xenobiotics in follicular fluid was found. In the future we will analyse the relationship between the presence of these xenobiotics and achieving succesful pregnancy.

Adult↗
PubMed2005

Quality of Life, Sustainable Future and medical education.

Substantial social and environmental changes in a global world as well as a new paradigm of medicine emphasizing high technology and evidence based approach bring to the current medicine many paradoxes. Undoubtedly, new era creates many positive opportunities and challenges for medical professionals. On the other side, traditional concept of medicine as basically humanistic "helping profession" is rather threatened. In this context, there is a need for a re-defining of medical curricula and to offer to the medical students the concepts and ideas which reflect a current development. Traditional public health terms such as "Primary Prevention", "Health Promotion", "Health Protection", "Health Determinants" should be re-defined and the new ones such as "Quality of Life" and "Sustainable Future" must be introduced as an integral part of medical education. The relevant concepts are discussed in the context of specific situation of the health care transformation in Central and Eastern European Countries.

Curriculum↗
PubMed2005

Some trace elements in coal of the Czech Republic, environment and health protection implications.

Mining for coal and its utilization have various impacts on the surrounding environment. Huge volumes of waste materials which are by-products of both the underground and open cast coal mining, pose one of the major environmental hazards in addition to air pollution caused by coal burning in power plants in the Czech Republic. Some of these risks could be reduced when having accurate and comprehensive data on coal quality. Statistical data processing of almost 35,000 coal samples from Late Paleozoic and Tertiary coal basins of the Czech Republic provided a unique information on the quality of lignite, sub-bituminous and bituminous coals and anthracites including the content of toxic trace elements (As, Be, Hg, Pb and Se). In this context related environment and health risks and protection implications are discussed.

Air Pollutants↗
PubMed2004

[Effect of toxic substances in the environment on reproduction].

OBJECTIVE: To summarize the findings about the influence of some xenobiotics on human reproduction, especially infertility. TYPE OF STUDY: Review article. SETTING: The Department of Obstetrics and Gynecology, 1st Medical Faculty, Charles University and the General Faculty Hospital, Prague METHODS: Analysis of literature. RESULTS: A review about the influence of some xenobiotics on human reproduction was given. In some there is a possible negative influence on the results of in vitro fertilisation program. It is a question of hormone disruptors, some heavy metals, some organic solvents, pesticides and smoking of cigarettes. CONCLUSION: In most of these xenobiotics there is direct evidence of their negative influence on reproduction and the results of in vitro fertilisation program. Therefore it is worth to continue in this evaluation.

Environmental Pollutants↗
PubMed2003

[Age-related post-translational modification of proteins in human tissue and its use determination of age in forensic medicine. Review].

This article deals with some of posttranslational modification of proteins which are, or could be useful to work out objective and standard methods for age estimation in forensic medicine. From many posttranslational modifications other than racemization, the evaluation of pentosidine, one of the products of nonenzymatic glycosylation, seems to be promising. The enlargement of menu of methods for age estimation is important mainly for forensic sciences when determination of the age of an unknown dead body is necessary. Morphological methods are quite often subjective and charged with errors.

Aging↗
PubMed2001

[Determination of the D-and L-forms of aspartic acid in intervertebral disk tissue as an indicator of age].

Assessment of age according to racemization coefficient of aspartic acid in dentin is considered a reliable method. Proteins which are isolated from dentin are non-collagenous proteins or collagen. As collagen is one of the most frequent proteins in the human body, the question arises whether the D-form of aspartic acid can be assessed also in other tissues and the racemization coefficient used for assessment of age. In the submitted work the author assessed to use the racemization coefficient in the tissue of the intervertebral disk. A lyophilized portion of the annulus fibrosus was hydrolyzed and the amino acids of the hydrolysate were estimated after derivation by gas chromatography on a chiral capillary column. The values of the racemization coefficient indicate limited possibilities to assess age from thus prepared tissue.

Adolescent↗
PubMed2001

[Determination of D- and L- forms of aspartic acid in Achilles tendon tissue as an indicator of age].

The presence of the D-form of aspartic acid was detected in collagen of dentin and the intervertebral disk before and assessment of its racemization coefficient was used for assessment of the age of subjects. Another tissue formed almost solely by collagen type I are tendons. Tendon tissue was not investigated so far with regard to the racemization coefficient and therefore the authors assessed the D-form of aspartic acid in the Achilles tendon. They used lyophilized tendon excisions which were hydrolyzed. Amino acids in the hydrolysate were derived to N-TFA isopropyl esters which were assessed by gas chromatography on a chiral capillary column. In all samples the D-form of aspartic acid was detected. The values of the racemization coefficient suggest the possible use of thus processed tissue with certain limitations.

Achilles Tendon↗
PubMed2001

Potential application of immobilized and perfused hepatocytes in environmental toxicology studies.

Conventional cellular models have contributed significantly to the understanding of many aspects of cell physiology and molecular biology. In these models cells are metabolically less active, due to the inefficient oxygenation and waste product buildup. Therefore perfusion methods for the cells are expected to improve cell activities. Cells have to be fixed in or on an appropriate inert carrier or support, which enables cellular perfusion, maintains integrated cellular functions and makes a bioreactor. Since isolated hepatocytes are extensively used in biomedical studies including those dealing with environmental pollutants or toxins and in xenobiotic biotransformation investigations, an efficient hepatocyte perfusion model has to be available for researchers. This research article is focusing on the value of hepatocyte immobilization as a laboratory bioreactor model and is shedding light on its potentiality in research related to public health. We demonstrate the application of this cellular model as a means to study representative phase I and phase II biotransformation reactions using hexobarbital hydroxylation and 7-ethoxycoumarin deethylation and 4-chloro 2-dinitrobenzene glutathione. Both phase I and phase II drug biotransformation in hepatocytes was demonstrated in this study non-destructively to the cells and in an efficient way. In spite of the aforementioned advantages, immobilized hepatocytes yet have relatively limited applications compared to conventional hepatocyte cellular systems. Reasons for this discrepancy are discussed. This cellular system may become popular due to the better performance of immobilized hepatocytes as compared to conventional hepatocyte culture and due to economic and ethical reasons. Naturally its applicability will cover several biomedical areas including basic research in environmental toxicology and other public health issues.

Animals↗
PubMed2001

The use of the D-, L- aspartic ratio in decalcified collagen from human dentin as an estimator of human age.

Among the methods dealing with the age estimation, the evaluation of the ratio of the D-, L- form of the aspartic acid in tissues with a low metabolic turnover is considered to be the most precise. We introduced demineralization of the dentin with 0.5 M EDTA adjusted to pH = 7.4. The advantage of such a procedure is that after demineralization we obtained pure insoluble protein (collagen) and soluble noncollagenous proteins in one step. In this study we analyzed insoluble collagen. The amino acids obtained after the hydrolysis were derivatized into TFA isopropyl esters and analyzed by gas chromatography on Chirasil L-Val capillary column. We analyzed human dentin from the lower canines. The correlation coefficient was 0.93 for our set of 71 persons. The result concurred with those of other scientists.

Adolescent↗
PubMed2001

Monitoring of occupational exposure in manufacturing of stainless steel constructions. Part I: Chromium, iron, manganese, molybdenum, nickel and vanadium in the workplace air of stainless steel welders.

Exposure to workplace airborne pollutants was examined in a group of 20 workers dealing mainly with welding, polishing, drilling and assembling of stainless steel constructions. Airborne particulate matter (APM) collected using both personal and stationary samplers was analyzed by instrumental neutron activation analysis (INAA). Quality assurance procedures of both sampling and analytical stages are described. Of the elements determined, results are presented for chromium, iron, manganese, molybdenum, nickel and vanadium. The median values of element concentrations exceeded the maximum admissible limits for workplace pollutants only for chromium, while for nickel the limit was exceeded in several individual cases. Sampling of hair, nails, blood, urine and saliva to be used for biological monitoring of the exposed and control groups is also described.

Adult↗
PubMed2001

Human exposure to endocrine disrupters: carcinogenic risk assessment.

Human exposure to endocrine disrupters (EDs) is widespread and is considered to pose a growing threat to human health. Recent advances in molecular and genetic research and better understanding of mechanisms of blastic cell transformation have led to efforts to improve cancer risk assessment for populations exposed to this family of xenobiotics. In risk assessment, low dose extrapolation of cancer incidence data from both experimental animals and epidemiology studies has been largely based on models assuming linear correlation at low doses, despite existence of evidence showing otherwise. Another weakness of ED risk assessment is poor exposure data in ecological studies. Those are frequently rough estimates derived from contaminated items of local food basket surveys. Polyhalogenated hydrocarbons are treated as examples. There is growing sense of urgency to develop a biologically based dose response model of cancer risk, integrating emerging data from molecular biology and epidemiology to provide more realistic data for risk assessors, public, public health managers and environmental issues administrators.

Carcinogens, Environmental↗
PubMed2000

Health risk assessment for inhalation exposure to arsenic.

Health risk assessment was used as the formal process to estimate the likelihood and magnitude of the health effects occurring in humans as a result of environmental and occupational exposure to polluting agents. This study was focused at estimating the human health risk of the general and working population living in the region polluted by arsenic for more than 40 years, from combustion of coal with high arsenic content in the power plant. The exposure to arsenic from inhalation was under investigation. A study period of 40 years (1973-1993) was chosen. The study period was defined taking into account, besides the availability of data, the temporal patterns of the technological processes and the trends over time of environmental concentrations. The results from the arsenic risk assessment study were used for the evaluation of the health risk for different population groups in the polluted areas and for different professions of workers exposed to As in a power plant. The results are applicable for the evaluation of risk in real conditions, for health surveillance and for remedial changes and a potential suggestion on technological improvement.

Adult↗
PubMed2000

Influence of cadmium and zinc sulphates on the function of human T lymphocytes in vitro.

Substances present in our environment influence the whole organism, including the immune system. Metals are one of the principal parts of these substances. It is generally supposed that they may have stimulating effect on immunity system in low concentrations in comparison with high concentrations in which they are toxic, with variations of each metal. There are differences between for example cadmium and zinc, and cadmium is toxic in low concentrations either. The effect of cadmium on the immune system has not been studied so deeply as the influence of zinc. In our work, we are interested in the study of immunomodulation caused by cadmium in comparison with the influence of zinc. We tested the effect of cadmium and zinc sulphates on human T lymphocytes in vitro. Molar concentrations of salts used in our work were from 10(-2) M to 10(-10) M. The influence of metals on lymphocytes in cell culture was studied by the expression of surface antigen CD69, blast transformation and IL-2 and IL-4 intracellular production after 2, 24 and 72 h cultivation. Cells were analyzed by flow cytometry using monoclonal antibodies. The results show more expressive differences in blast transformation. There are stimulating effects of cadmium in concentrations 10(-3) M, 10(-4) M and 10(-8) M, and zinc 10(-3) M. The most suppressive effect is in concentrations 10(-10) M of cadmium and 10(-8) M of zinc. The highest CD69 expression is in concentrations 10(-4) M to 10(-6) M of cadmium, and 10(-3) M of zinc. There are minimal differences in intracellular cytokine production in CD4+ lymphocytes effected by various metal concentrations used and between cadmium and zinc salts after 2 hours cultivation. There is the elevation of cytokines negative cells after the cultivation lasting 24 hours. Our investigation of metals' influence by different methods shows possibilities for further research.

Adult↗
PubMed1999

Electro-ionic microclimate and materials used in the indoor environment.

In 170 experiments relationships between 31 different materials used in indoor premises and ionization of the air in their proximity were assessed. The influence of temperature and relative humidity on ionization of air was studied. It was observed that the materials tested could be divided into four groups according to their behaviour towards ambient light negative ions. From the results obtained it follows that the more humid and thus more conductive the material in question, the greater is its influence on the ionization of the air. The most important criterion influencing the relationship of the material and ambient air ionization is the magnitude of the contacting surface of the material that is given by its ruggedness and structure. In natural materials considerable porosity may be expected. In contrast smooth surfaces without pores can be expected in materials produced by melting. Other physico-chemical properties of the materials are manifested in a more discrete way.

Air Ionization↗
PubMed1999

Environmental health in the Baltic region--toxic metals.

Recent reports on concentrations of lead, cadmium, methylmercury, arsenic and nickel in some biological media in populations in the Baltic region are reviewed. In particular, children in parts of Poland, the Czech Republic, and Germany have uptakes of lead sufficient to cause adverse effects on the central nervous system and kidneys. Cadmium exposure is also high in Poland. Slight cadmium-induced effects on the kidneys have been reported from Germany and Sweden. Methylmercury uptake is dependent upon the intake of fish, in particular from contaminated lakes and rivers in Sweden and Finland, as well as the eastern coast of the Baltic Sea. There are some indications of immunotoxic effects associated with the intake of such fish. However, fish also contain other immunomodulating agents. Exposure to arsenic seems to be low everywhere in the Baltic region. There is high nickel exposure in northern Russia.

Adolescent↗
PubMed1999

[Health status of persons occupationally exposed to chromium, nickel, manganese and polycyclic aromatic hydrocarbons].

Occupational environment monitoring and biological-medical monitoring of persons professionally exposed to welding fumes have been performed. Chromium, manganese and polycyclic aromatic hydrocarbons in welding fumes represents an important health risk. Pollutant concentrations found in metal welding fumes represented only fractions of those acceptable ones. Polycyclic aromatic hydrocarbons have been reached the concentration found in a busy road crossing in Hradec Králové (compared with these as in Czech Republic no maximum acceptable levels for PAHs having been declared). Family, personal and occupational history have been taken. Health state including total haematological count, biochemical and cytogenetical changes of 19 stainless steel welders were checked-up. The level of mercapturates in urine were examined as well. The data were statistically compared with those of non exposed (control group). No changes witnessing the above mentioned risk factors influence on the haematological, biochemical and cytogenetical findings were ever proved. In conclusion, our results did not confirm an increased professional risk in this group of welders.

Adult↗
PubMed1999

[Biological monitoring of occupational exposure in welders of stainless steel. Immunologic methods].

Biological monitoring of occupational exposure to toxic compounds enables an early detection of adverse health effects. Apart from the standard biological monitoring methods of occupational exposure represented by metabolites and enzymes activities analysis also immunological detection methods seem to be promising. The changes of immunological system are demonstrable extraordinary sensitive markers of load of organism. The process of welding belongs between important sources of pollution of working environment with heavy metals and other harmful compounds including polycyclic aromatic hydrocarbons. According to IARC classification the welding fumes are included into group 2B and are supposed as possible human carcinogens. Numbers of different epidemiological studies have proved relationship between welding and serious health disorders namely malignancies. We recorded a number of changes in immunological parameters when compared with those in control group in our study. The results of analysis were statistically evaluated. The statistically significant reduction of number of phagocytosis capable cells was found in the group of welders when compared with the control group. The levels of neopterin, beta-2-microglobulin and IL-1 beta have indirectly monitored cell component of immunological response. In the case of these markers a statistically significant increases were found in the group of welders. We found statistically significant IgM decrease and statistically significant IgA increase in humoral responses with the same group when compared with control group.

Adult↗