Biomedical subjects
Publications and source records attributed to V Bencko.
Paper concerns evaluation of results of age estimation based on the increase of D-aspartic acid during aging. Samples of dentin from lower canine teeth were used as experimental material. In addition, analytical pitfalls and new possibilities of d-amino acids detection were discussed.
Breast milk samples were collected and analysed within a comprehensive programme co-ordinated by WHO EURO to evaluate the possible health risk for breast-fed infants in chosen localities of European countries ('exposed' and 'control' ones). The samples of breast milk were collected, stored transported and analysed by a standardised study protocol to assure the comparability of the results from different areas (of 19 European countries). The study included three categories of chemicals: polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs), dioxine like polychlorinated biphenyls (PCBs) and other PCBs. The results obtained confirmed the correct choice of 'exposed' and 'control' regions in the Czech Republic as a suitable tool used to identify certain geographical areas with relatively high exposure levels for further risk management actions and possible follow-up epidemiological studies. The results obtained have shown high levels of PCBs in exposed region but not in the dioxine-like fraction, that ranged within a lower rank of a relevant European data. PCDs/PCDFs levels ranged in the same lower rank of values in comparison with e.g. Benelux countries. The data of this study does not confirm ideas about wide spread excessive exposure of central European population to polyhalogenated hydrocarbons via excessive contamination of a local food basket.
The epidemiology of tumour diseases is one of the basic fields of non-infectious epidemiology. When in the first half of this century the most serious infections had been put under control in Europe and North America other kinds of diseases such as carcinomas emerged. Incidence of these diseases seem to be epidemical, exactly in those parts of the world. Carcinomas have been recorded as the second largest group of death causes nowadays. Despite frequent efforts to refer to the tumour diseases as the civilisation evils, we have to weigh critically the opinion that malignant tumours are the privilege of industrial countries whereas the primitive nations have recorded these types of diseases rarely. The Cancer Register in Mengo Hospital, Kampala, of 1897-1956 and other evidence have failed to confirm the lower cancer incidence in the local population at the beginning of the colonisation period than it was in Europe of that time. The paleopathological analysis of skeletal relicts in Central Europe burial places during the ceramic volute era near Stuttgart, Germany, have proved the total proportion of over 10% of traces indicating the presence of tumours in the available complete skeletons. The authors discuss the epidemiology of cancer, risk factors and chances of prevention.
Scientific and technical development contributed on the one hand greatly to easier living conditions, on the other hand there is however substantially greater danger threatening not only the life of man but also of nature, of the entire living environment. At present the problem of the possible part played by this phenomenon in reproductive disorders is in the foreground. Via the food chain heavy metals, toxic trace elements and polyhalogenic hydrocarbons penetrate into the organism. They accumulate in the organism and thus also in the reproductive tract and may have an impact on fertility. Some elements with a possible negative impact on reproductive health are in such low concentrations in tissues that only contemporary methods of their detection make it possible to map their presence in the organism. They are called trace elements. Toxic ones comprise cadmium, mercury, lead and arsenic. The mechanism of the negative action of cadmium in the organism is most probably due to its competition with the vitally important trace element--zinc. It was therefore the objective of the present investigation to trace the presence of cadmium and zinc in the organism of 100 sterile women included in an IVF programme: in blood and follicular fluid (i.e. in a medium which surrounds the gamete--the oocyte) and to follow up their concentrations in relation to achievement pregnancy. Cadmium and zinc in blood and follicular fluid were assessed on a mass spectrometer with induction bound plasma as the source of ions (ICP-MS), Varian Co. produced in 1994. The assessed mean levels (microgram/l) of cadmium in blood (2.88 s 2.71) and follicular fluid (1.25 s 0.55) in the group of conception cycles did not differ significantly from mean blood levels (2.82 s 2.22) and follicular levels (1.16 s 0.55) of non-conception cycles. The mean zinc levels in blood and follicular fluid did not differ either in the group of conception and non-conception cycles. Very significant are the differences in the blood and follicular fluid levels, the levels in follicular fluid being significantly lower. We may speak of a protective barrier of the oocyte formed by the follicle (probably the cells of the granulosa) against blood. Thus no relationship was found between the cadmium concentration in blood and follicular fluid of women where pregnancy was achieved and non-pregnant women. The possible cause of fertility disorders in conjunction with toxic elements is probably in damage of the granulosa cells and thus their dysfunction as regards production of steroid hormones with full impact on female fertility (hormone disruptors).
The aim of this study was to analyse a potential connection between the chosen parameters of the quality of the environment and the mortality pattern of residents in the Czech Republic. By means of linear regression selected parameters of the quality of the environment in the districts were compared with mortality rates and some other indices of the health status of the inhabitants of the districts. The region of Prague was excluded from our study because of a substantial gap in environmental data set. The percentage of inhabitants who live in an environment evaluated as "acceptable" served as the independent variable. The total mortality rate or some other health data were the dependent ones. An analysis of our data set has shown that the environment "influences" mortality by 30% (r2 = 29.6%) in men and even by 40% (r2 = 43.6%) in women. Standardized mortality rates by causes of death and some other parameters of the health status of the population were also compared with the chosen parameters of the quality of the environment. A statistically significant linear association was found between the quality of the environment and the standardized mortality rate of malignant neoplasm in both men (r2 = 13.8%) and women (r2 = 32.4%), the standardized mortality rate of diseases of the circulatory system in women and the incidence of TB in men. The highest correlation was found between the quality of the environment and the incidence of gonorrhoea (r2 = 51.7%). Apparently this dependence is not a causal one. It could be interpreted as a dependence between the quality of the environment and the social behaviour of its inhabitants. On the verge of significance was male mortality from injury and mortality from suicide. No association has been found between the quality of the environment and the standardized mortalities from diseases of the respiratory system, the infant mortality rate till one year of age, incidence of congenital anomalies and the incidence of diabetes mellitus.
Evidence was provided that in a repeatedly irradiated bacterial suspension of Escherichia coli K12: AB 1157, 1886, 2463, under the described experimental conditions, gradually mutants more resistant to UV radiation survive. Under these circumstances it may happen that selection and an increase of bacterial clones with an increased UV resistance develop, manifested by a reduced effectiveness of UV radiation during repeated irradiation. Although the cumulating damage of DNA in microbes can lead to a reduction of their survival as well as a reduction of their absolute numbers, it can be hardly assumed that during practical use in air conditioning units or during disinfection of drinking water all bacteria will be destroyed. In that case even repeated UV irradiation is not necessarily a reliable disinfection tool.
The effects of formaldehyde on human beings has been a subject of study in the former Czechoslovakia since the beginning of the 1980s. The first studies quite naturally arose from concern over its effects in occupational settings. Initially, the allergic effects of formaldehyde on the skin were studied. Two main approaches to the study of the biologic effects of formaldehyde on humans were employed. The cytogenetic analyses of peripheral lymphocytes and immunological analysis of selected humoral immunity parameters were used to demonstrate the formaldehyde exposure in both occupational and non-occupational indoor environment. The analysis of the results, especially from the non-occupational settings (e.g. school classrooms), was beset with problems with interpretation and lead to suggested maximum acceptable concentration (MAC) values that were unrealistically low, ranging from 0.035 mg.m-3 (whole day mean) and short term-up to 30 minute sampling 0.050 mg.m-3. These rather stringent requirements are fully acceptable for the open air. However, they are difficult to achieve in indoor air settings, and are open to criticism from the point of view of exposure assessment. Because of the problems in interpreting genotoxic and immunological parameters, a risk assessment approach was adopted for this discussion.
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The concentrations of persistent organochlorine contaminants including polychlorinated biphenyls (PCBs), DDT (its isomers and metabolites), hexachlorobenzene (HCB) and isomers of hexachlorocyclohexane (HCH) have been determined in human milk samples from the three regions in the Czech Republic. Results were generated by the congener-specific analyses (two-dimensional high resolution gas chromatography). The results are compared with the similar studies from other industrial countries (Norway, Great Britain, the Netherlands and Germany). Typical patterns of major PCBs contained in analyzed breast milk samples are presented. PCB No.153 was the dominant congener in all the samples. A good correlation was found between the sum of PCBs and PCB No.:153 (r = 0.99), constitutes approx. 30% of calculated PCBs content.
Experimental exposures using laboratory Wistar rats inhaling the exhaust gases derived from a two-cycle combustion engine under the chamber conditions have been carried out. Immune response reflecting a burden of the respiratory system in the exposed animals following the respiratory exposure has been investigated. In variously designed exposure experiments, the dynamics of pulmonary alveolar macrophages (PAM) activity to phagocyte particular antigen (sheep red blood cells), the hemolysis production, the total serum complement level and the capacity of the pulmonary clearance from the inhaled silica dust have been examined. The findings revealed the depressed ability to produce antibodies against sheep red blood cells (SRBC) in case of prolonged animals exposure during the time-interval of antibodies production. PAM phagocytic activity decreased considerably as well, in the first phases of the SRBC phagocytosis. The total serum complement level was found to be decreased in consonance with the decreased hemolysins production. The pulmonary clearance from the inhaled silica particles was statistically significantly elevated in the animals exposed long-term before the dusting only. In case of the prolonged exposure during the lung clearance period of 25 days, the exposed animals did not show the difference anymore, if compared to the non-exposed group.
The aim of presented review is to address the most relevant issues related to the health effects caused by the human exposure to lead, as they have been recognized in Czech Republic in the period of 1992-1994 within the framework of the National Integrated Programme on Environment and Health (NIPEH) approved in 1992 and supported by WHO-European Centre for Environment and Health (WHO-ECEH), Bilthoven, The Netherlands and by the Government of the Netherlands. Basic sources of environment exposure to lead are identified and the fate of lead in the individual compartments of the environment is discussed. Relevant methods used for the exposure evaluation are summarized and the highest-risk group of population is defined. Attention is being paid to the effects of the long-term exposure to low lead levels, while other exposure settings are intentionally omitted. Interventional measures developed in the Czech Republic in attempt to reduce the environmental exposure are introduced. Instead of presenting specific data, current state-of-art and general trends are presented; list of references tries to combine the internationally recognized studies with those coming from national sources.
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The present study was designed to investigate the ameliorative effect of cyclosporine A (CsA) pretreatment on an anoxia/reoxygenation injury model by using immobilized perfused hepatocytes. Rats received an i.p. injection of two successive doses of CsA (5 mg/kg/day). Twenty-four hours later hepatocytes were isolated from CsA-treated and control rats. After hepatocyte isolation, immobilization, perfusion, induction of anoxia/reoxygenation, the structural and functional integrity of the hepatocytes was followed in a perfusion medium by measuring the leakage of lactate dehydrogenase (LD) and the time course of urea biosynthesis. CsA pretreatment reduced the initial rate of urea synthesis during normoxia but reduced the drop in the relative percentage rate of urea synthesis during the period of anoxia. LD leakage was increased threefold by anoxia and sevenfold by reoxygenation in cells of untreated animals. After CsA pretreatment in vivo, hepatocytes showed no increase in LD leakage into the medium. These findings demonstrate that the perfused immobilized hepatocytes can be used as a cellular model to assess the effects of liver insults such as anoxia/reoxygenation injury and that CsA modulates the injury. The mechanisms of CsA beneficial effects at the experimental level remain to be elucidated.
The use of human hair analysis technique is far from being the universal tool for monitoring exposures to environmental pollutants and considering the broad spectrum of pollutants encountered in the general environment one can hardly expect that such a screening tool would ever exist. However, for a majority of toxic trace metals this technique has proved to be a well-suited biological marker of occupational and environmental exposure of man. One of the essential conditions for ensuring the realistic evaluation of excessive population exposure is the examination of sufficiently large population groups and the use of group diagnostics methodology in environmental epidemiology studies. The method of hair analysis appears to be ideally suited for use in pilot prospective studies. If an excessive exposure is detected it is recommendable that the epidemiological examination be completed by analyses of other biological materials, most often blood and urine, in order to obtain a closer specification of the degree of exposure in the respective population.
The availability of accurate trace element reference values in human tissues represents an important indicator to the health status of the general population and occupational groups exposed to trace elements. The EURO TERVIHT project (Trace Element Reference Values in Human Tissues) aims to establish and compare trace element reference values in tissues from inhabitants of the European countries as baseline values for clinical/toxicological assessment studies. In this context, one of the first steps considered is the critical evaluation (state of the art) of existing literature on trace element reference values in blood, serum and urine in the general population of each European country. This paper reviews the Czech and Slovak situation by assessing studies carried out in these countries for Al, As, Cd, Co, Cr, Cu, F, Mn, Hg, Ni, Pb, Rb, Sc, Se, V and Zn in blood, serum and urine. These studies show that most of the data available do not meet criteria designed recently for deriving reference intervals, especially regarding the number of subjects, the age of population sample studies as well as the use of appropriate sampling techniques and quality assurance procedures. Elements which present the highest potential risk for health in Czech and Slovak populations and for which reference values should be urgently established are: Cd, Hg, Pb (major pollutants); As, Cr, Ni (carcinogenic metals); Al, F, Mn, Tl, V (released into the environment by coal combustion and other industrial activities); Pt (increasing use of Pt catalyst in petrol-driven automobiles); essential trace elements such as I, Se and Zn for which a deficiency in Czech and Slovak populations was detected or is suspected.
Malignant tumours account for about 20% of the mortality of our population. Their epidemiology deserves therefore, no doubt, greater attention than it had so far. In the context of epidemiology of non-communicable diseases which is still not sufficiently appreciated in this country, it is desirable to pay due attention also to risk factors of malignant processes. It is a classical example of essential multidisciplinary collaboration and of comprehensive approach at least of the clinician working with the patient, the hygienist who describes truthfully the exposure to risk factors, and the epidemiologist who will design the most suitable type of study and method of evaluation of the assembled results. Patience and systematic work, frequently extending over many years, is a condition sine qua non.
A biomonitoring study using domestic rabbits (Chinchilla) aimed at the exposure and impact risks assessment of emissions released into the ambient air from a mercury-recycling plant has been carried out. Groups of rabbits were exposed to the emissions during 6 months at biomonitoring stations built up in two localities (Rudnany and Matejovce) in the distance of about 3 and 6 km around and downwind from the mercury-producing plant. The aim of the biomonitoring was to trace the translocation of inhaled inorganic Hg in body tissues and the immunotoxic impact of the emissions in the exposed mammalian organism in comparison to a non-exposed animals living outside the polluted area. The content of mercury (as a major pollutant in the ambient air in that area) in body tissues was done spectrometrically using a Trace Mercury Analyser TMA-254. Content of mercury and the other metals in the rabbits' hairs was determined by neutron activation analysis. A statistically significant increase of the inorganic Hg content in the specimens of kidneys, lungs, liver, thigh bone, heart muscle and brain was observed. Concerning the hairs, a statistically significant elevation of Hg and other elements (As, Cd, La, Zn, Na, K, W, Sr) has been found. The body tissue reaction to the increased accumulation of mercury has been investigated by a direct immunofluorescent method to search for body tissue immune complexes. The significant increase of Hg content determined in the organs (especially in kidneys and liver) of the exposed animals was also traced by the presence of immunofluorescent antibodies. In addition, the immunofluorescent antibodies in the myocardium have been proved.(ABSTRACT TRUNCATED AT 250 WORDS)
In the outskirts of Cairo, some 40,000 people live on garbage dumps. These people form a closed population whose socio-economic problems are identical. The pollutants are evenly distributed. Up to 30% of the garbage on the polluted area, which cannot be recycled, is burned, resulting in a high concentration of pollutants in the environment. The concentrations of heavy metals, dioxins/furans, PCB, PAH in dust deposit and soil were measured as well as the air pollutants SO2, HCl and CO. It was shown that while the systemic immune system is only affected to a very small degree, secretory immunoglobulin A is strongly affected by the emissions. It could be demonstrated also an increased readiness for allergic respiratory disease, through the proof of hyperreactive mucous membranes. In the polluted area, 58% of the examined children were affected, whereas in the control area only 22% displayed a hyperreactive mucous membrane. Also the concentration of NANA (N-acetyl-N-neuraminic acid) in the serum, as a unspecific marker of cell irritation, was high in the serum of children from the polluted area. Most of the pollutants detected can also be observed in the industrialized regions, especially in combination with incinerating plants. In this way, this study suggests the synergistic effects of pollutants.