Biomedical subjects

P Zeman

Publications and source records attributed to P Zeman.

At least 19 recordsLinked to original sources

PubMed2004

GIS tools for tick and tick-borne disease occurrence.

Geographic information systems (GIS), their fundamental components and technologies are described. GIS is a computer-based system enabling the storage, integration, query, display and analysis of data using information on data location. Further, remote sensing (RS) methods and their application in landscape characterization are described. Landscape pattern analysis, combined with statistical analysis, allows the determination of landscape predictors of disease risk. This makes RS/GIS a powerful set of tools for disease surveillance, enabling the prediction of potential disease outbreaks and targeting intervention programs. The 'pre-GIS era' is briefly described including the early mapping of tick distribution, analyses and the display of biogeographical and medical data. The theory of natural focality of diseases (NFD) is explained and its significance in tick-borne diseases (TBD) research is discussed. Many problems of tick ecology and TBD epidemiology and epizootology have been addressed by means of GIS and examples of these studies are presented and discussed.

Animals↗

PubMed2004

[Antibodies against mosquito-born viruses in human population of an area of Central Bohemia affected by the flood of 2002].

In the Central-Bohemian area affected by the flood of 2002, 497 residents were screened for antibodies against the mosquito-borne viruses Tahyna (TAHV), West Nile (WNV), Sindbis (SINV) and Batai (BATV; syn. Calovo) using the haemagglutination-inhibition (HIT) and plaque-reduction neutralization (PRNT) tests. Blood samples were collected in September 2002 when the mosquito populations showed the maximum density following the flood. Antibodies against TAHV (16.5% persons in PRNT, 14.9% in HIT), SINV (1.4% in HIT) and BATV (1.4% in HIT, 0.2% in PRNT) were detected. Although 6.8% and 1.2% of the subjects tested reactive with WNV in HIT and PRNT, respectively, the results were interpreted as cross-reactivity with tick-borne encephalitis virus. The seroprevalence of TAHV (both in PRNT and HIT) showed no association with gender (15.8% of males, 16.9% of females), increased with age (1.4% of persons younger than 20 years, 11.2% of persons aged between 20 and 50 years, and 26.2% of persons older than 50 years were positive), and correlated with the mosquito peri-residential challenge (5.0% residents seropositive in a mosquito-free control zone D--mostly Prague, 14.7% in a mild-risk zone C, 20.5% in a moderate-risk zone B, and 28.0% in the most heavily mosquito-infested risk zone A). The highest TAHV seropositivity rate (> 25%) was found amongst the inhabitants of the villages Obríství, Kozly, Tuhan, Chrást, Chlumín and Hostín. Paired blood samples were obtained from 150 of the persons at a 6-month interval: an infection episode with TAHV during or after the flood was clearly evidenced in one person living in Obríství, and less convincing findings of recent TAHV infections were found in other three residents of Chlumín and Obríství (seroconversion and/or significant antibody titres increase detected in HIT only). This serosurvey indicated the existence of an active natural focus of Valtice fever (TAHV infection) stretched along the river Labe nearby Neratovice (Obríství, Chlumín, Tuhan; Kozly, Tisice, Chrást), and a low TAHV activity area along the lower reaches of the river Vltava between Zloncice and Bukol/Zálezlice. An increased population density of mosquitoes after the flood may have boosted the incidence of mosquito-borne virus diseases, particularly Valtice fever, in Central Bohemia. An optimum prophylactic strategy to control these diseases would be epidemiological surveillance (including monitoring of both the density of mosquitoes and their rate of infection with viruses in natural foci) on the basis of which antiepidemic measures such as integrated mosquito control can be taken.

Animals↗

PubMed2002

[Antibodies to granulocytic Ehrlichiae in the population of the western and central part of the Czech Republic].

A total of 963 subjects in four groups from western and central Bohemia were examined in 1998-2000 for the presence of antibodies against granulocytic ehrlichiae. In the indirect fluorescence assay, a specific antigen from ehrlichiae (HGE) cultivated in-vitro and commercial anti-IgG and anti-IgM secondary antibodies were used. An overall prevalence of HGE antibodies of the class IgG corresponding to titres < or = 1/80 and 1/160 was found to be 21.0 and 13.5%, respectively, with a predominance during the warm season (May-October). The seasonal seroprevalence was discriminated best from an all-year background by titres 1/80-1/160. Elevated antibodies were found more frequently in older subjects; no effect of gender was observed. Antibodies of the class IgM were detected only exceptionally and did not exceed the titre of 1/40. Only minor differences were observed in the prevalence of HGE antibodies between groups differing geographically or by the presence of Borrelia antibodies. The seasonal incidence of HGE antibodies did not differ significantly from that of Borrelia antibodies.

Adolescent↗

PubMed2002

[Comparison of extraction methods for detection of Ehrlichia DNA in whole blood using PCR].

The author compared nine methods for isolation of specific DNA of the etiological agent of human granulocytic ehrlichiosis from human blood for examination of the PCR. To full blood of healthy donors a laboratory culture of the agent was added and the effectiveness of isolation an stability of the template was tested under conditions when the blood was fresh or frozen. For universal use QIAamp (QIAGEN) was most suitable, frozen blood was extracted best using NucleoSpin Tissue (Macherey-Nagel).

Anaplasma phagocytophilum↗

PubMed2001

Differential effects of pentaerythritol tetranitrate and nitroglycerin on the development of tolerance and evidence of lipid peroxidation: a human in vivo study.

OBJECTIVES: We investigated the development of nitrate tolerance after continuous exposure to nitroglycerin (GTN) as compared with pentaerythritol tetranitrate (PETN) in humans. BACKGROUND: Sustained therapy with GTN causes tolerance and has been associated with increased production of free oxygen radicals by the endothelium. Pentaerythritol tetranitrate is an organic nitrate that has been used in the therapy of angina. There have been no investigations concerning the development of tolerance to PETN in humans. Animal investigations suggested that continuous therapy with PETN does not cause increased free radical production or hemodynamic tolerance. METHODS: We randomized 30 healthy volunteers to continuous GTN (0.6 mg/h/24 h), long-acting PETN (60 mg orally three times a day) or no treatment (control group) for seven days. We studied systemic blood pressure responses and venous volume responses to GTN with strain-gauge plethysmography. The levels of cytotoxic aldehydes and isoprostanes were measured as markers of free radical-mediated lipid peroxidation. RESULTS: Tolerance, as demonstrated by blood pressure and forearm plethysmography, developed in the GTN group and was absent in the PETN group (p < 0.05). Therapy with GTN was associated with a significant increase in plasma markers of lipid peroxidation. This response was not observed in those treated with PETN (isoprostanes: control: 38 +/- 5; GTN: 59 +/- 6; PETN: 38 +/- 3 microg/ml; p < 0.005). CONCLUSIONS: Treatment with PETN does not cause tolerance and is not associated with evidence of increased free radical production.

Administration, Cutaneous↗

PubMed1999

Epizootiologic background of dissimilar distribution of human cases of Lyme borreliosis and tick-borne encephalitis in a joint endemic area.

Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are co-endemic in some parts of Europe, however, their distribution differs despite a common tick vector and comparable animal hosts. A serosurvey of game and small mammals was made in a highly endemic area and compared with historical data in human cases; the epidemiologic risk and the population density of game were modelled using a geographic information system. While LB-risk corresponded with an overall population density of game (red deer, roe deer, mouflon, wild boar) regardless of mouse abundance, TBE-risk suggested a dependence on the abundance of mice on the one hand, and game, particularly roe deer, on the other. While the prevalence of TBE-antibodies generally grew with the game's age, it was virtually constant at about 65% in LB irrespective of species. It implies a cumulation of scarce TBE-infection histories during the game's lifetime, and thus a limited size of TBE-foci relative to the living space of these animals, as well as omnipresent LB-foci, in which the animals became continuously re-infected. More ecological prerequisites seem necessary to keep TBE circulating in nature which may be responsible for its confined distribution.

Age Factors↗

PubMed1999

Mosaic pattern of Borrelia infection in a continuous population of the tick Ixodes ricinus (Acari: Ixodidae).

An array of 12 20 x 20 m quadrats in a mixed forest near Poteply, Central Bohemia, Czech Republic, was investigated for the abundance and spatial distribution of host-questing Ixodes ricinus nymphs and their infection with borreliae. Tick densities were estimated by flagging and their borrelia infection status was determined by direct immunofluorescence. While the tick population appeared to be continuous and homogeneous based on quadrat counts, their infection with borreliae evinced a mosaic pattern. The nymphal infection rates ranged between 1.6 and 10.5% (mean = 6.0%) with significant differences between adjacent quadrats. Home ranging of small rodents (Apodemus flavicollis and Clethrionomys glareolus) inhabiting the forest seems to be responsible for the spatial pattern of borrelial infection.

Animals↗

PubMed1999

Tick-borne encephalitis and Lyme borreliosis: comparison of habitat risk assessments using satellite data (an experience from the Central Bohemian region of the Czech Republic).

The vegetation types have been used as the indicators of an ecosystem suitable for high incidence of Ixodes ricinus ticks and their hosts, for the circulation of tick-borne diseases pathogens and, accordingly, for the existence of natural foci of these infections, namely tick-borne encephalitis (TBE) and Lyme borreliosis (LB). The method of remote sensing offers a suitable solution to this problem. We attempted to prepare the habitat risk assessment maps on the territory (11,500 km2) of Central Bohemia (Czech Republic) using Landsat 5 TM imagery. Nine forest classes have been recognized in the satellite data and further identified in a field checking botanical survey. Beside the conclusions dealing with the importance of different plant types for I. ricinus occurrence, also the epidemiological TBE and LB maps based on human cases contracted in the territory under study were exploited for the evaluation of particular forest classes significance, and for the comparison of results achieved. Apart from a general pattern of risk gradation from coniferous to deciduous wood types, both TBE and LB data suggest a specific position of the heterogeneous deciduous wood class (including mainly young deciduous stands and stand ecotones with highly heterogeneous structure). Epidemiological significance of the other particular forest classes was assessed by the degrees of positive class-to-risk associations (see Table 1 and 2).

Animals↗

PubMed1998

A conserved region of the R domain of cystic fibrosis transmembrane conductance regulator is important in processing and function.

The R domain of cystic fibrosis transmembrane conductance regulator (CFTR) connects the two halves of the protein, each of which possess a transmembrane-spanning domain and a nucleotide binding domain. Phosphorylation of serine residues, which reside mostly within the C-terminal two-thirds of the R domain, is required for nucleotide-dependent activation of CFTR chloride channel activity. The N terminus of the R domain is also likely to be important in CFTR function, since this region is highly conserved among CFTRs of different species and exhibits sequence similarity with the "linker region" of the related protein, P-glycoprotein. To date, however, the role of this region in CFTR channel function remains unknown. In this paper, we report the effects of five disease-causing mutations within the N terminus of the CFTR-R domain. All five mutants exhibit defective protein processing in mammalian HEK-293 cells, suggesting that they are mislocalized and fail to reach the cell surface. However, in the Xenopus oocyte, three mutants reached the plasma membrane. One of these mutants, L619S, exhibits no detectable function, whereas the other two, D614G and I618T, exhibit partial activity as chloride channels. Single channel analysis of these latter two mutants revealed that they possess defective rates of channel opening, consistent with the hypothesis that the N terminus of the R domain participates in ATP-dependent channel gating. These findings support recent structural models that include this region within extended boundaries of the first nucleotide binding domain.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

[Social work with the elderly--current orientation and strategies].

Social work for the elderly in a demographical ageing society is not justified per se, but has to prove its utility under the altering social conditions of the changing age-structure. In the field of practice, this has led to an increasing need for professional orientation and to searching for profiles of performance with greater attraction. As manifold as the target groups are the spectra of social work for the elderly is also manifold in its content and methods. Nevertheless, we are able to recognize some general orientations and strategies, which are conceptual adaptions from social work in general, cultural work and educational work--combined with fundamental supplies of social gerontological knowledge. In this sense, social work, for the elderly--in its most advanced realms--should be integrated into an ageing-policy concept, which is of relevance for the society as a whole.

Aged↗

PubMed1998

Lyme borreliosis habitat assessment.

Tick ecologists throughout Europe provided descriptions of Lyme borreliosis habitats according to a standardised format and data for 105 habitats in 16 countries were received. The data showed that high risk situations, as defined by the presence of large numbers of B. burgdorferi sensu lato-infected nymphal I. ricinus, occur in heterogeneous deciduous woodland, usually with a recreational function and with a diverse fauna, usually including deer. Large numbers of ticks occurred in some other habitats, but infection prevalence was usually low. The situation for adult I. ricinus was similar but less clearly defined. Tick infection rates were found to be lower in western Europe than in the east, and the infection rate in I. persulcatus, the most easterly vector species, was markedly higher than in I. ricinus. In the vast majority of habitats the infection rate in adult I. ricinus was greater than in nymphs. Larvae were rarely found to be infected.

Animals↗

PubMed1998

Predictive map of Ixodes ricinus high-incidence habitats and a tick-borne encephalitis risk assessment using satellite data.

The main objective of this project was to predict Ixodes ricinus abundant habitats reliably as a means of tick-borne encephalitis (TBE) risk assessment for the prevention of this disease. The vegetation types were used as the indicators of an ecosystem suitable for tick occurrence, for TBE virus circulation and, accordingly, for the existence of natural foci of this infection. Remote sensing methods were used to determine the indicative plant cover. Satellite data covering an experimental area of 70 x 70 km in Central Bohemia, the Czech Republic, was acquired by the Landsat 5 TM scanner. Nine forest classes were recognized in the experimental area by successive supervised and unsupervised classifications and identified in a field-checking botanical survey. An epidemiological TBE map based on human cases contracted in the territory under study was exploited for the evaluation of risk in particular forest classes. Predictive maps are expressed both in digital and in printed forms at a scale of 1:300,000 for an overall risk evaluation and at a scale of 1:25,000 for a detailed local orientation.

Animals↗

PubMed1998

[Prediction of sites with an increased risk of infestation with Ixodes ricinus and tick-borne encephalitis infection in the Central Bohemia Region based satellite data].

Based on elaboration of a prediction map of sites of increased incidence of Ixodes ricinus associated with an increased risk of attack on humans and activation of the virus of tick-borne encephalitis it was assumed that different types of vegetation can serve this purpose as suitable indicators. For assessment of these sites and their location on the territory of the Central Bohemian region (on an area of 11,508 sq.km) data from spectral analysis of reflected light recorded by a scanner, Thematic Mapper, working on satellite LANDSAT 5 with a spatial resolution of 30 m, obtained in six bands of the visible and near infrared spectrum resp. was used. Digital satellite data were processed in station IBM RISC 6000 using the professional software EASI/PACE of PCI Co. Inc. Canada. First by supervised classification seven main classes describing the position of the whole area were differentiated and then by a combination of unsupervised and subsequently supervised classification the forest areas were divided into nine classes of forests (with a different structure and different composition as to species), which have a different incidence of ticks. These classes were then compared by statistical methods with the epidemiological map of risk of acquisition of the tick-borne encephalitis virus. This resulted in the finding that coniferous tree forests ("1" and "2") are practically devoid of risk, while mixed and deciduous forests ("3" to "9") involve a varying degree of risk. The maximum risk was found in class 6 which comprises very heterogeneous young deciduous growth and ecotones. The results are presented graphically on the specimen of the prediction map (part of the classified picture supplemented by topographic signs at scale 1:25,000) and on classified satellite picture of the whole area (scale of the original computer printout 1:300,000). In the legend the grade of risk of different classes is expressed verbally, corresponding to values of the Spearman coefficient of rank correlation (Table 1). The laboratory tests were verified and characterized from the botanical aspect during the field investigation.

Animals↗

PubMed1998

Borrelia-infection rates in tick and insect vectors accompanying human risk of acquiring Lyme borreliosis in a highly endemic region in Central Europe.

The methods of spatial statistics were applied to assess the geographical pattern of risk of Lyme borreliosis in Central Bohemia, the Czech Republic, based on retrospective data on disease contractions. The statistical risk was then compared at 15 selected localities with the infection challenge presented by ticks and insects carrying borreliae. Over 5,000 Ixodes ricinus (L.) ticks and 390 haematophagous dipterans were screened by direct immunofluorescence method, and the spatial and seasonal variance of infection rates were studied. Infected ticks were found at each locality throughout the warm season; in nymphs, sample infection rates ranged from 4.9% to 23.1% with a mean of 14.5% in spring, from 7.7% to 28.7% with a mean of 16.1% in summer, and from 7% to 20.6% with a mean of 13.6% in autumn. The statistical risk was found to correlate well with an average nymphal infection challenge, i.e. I. ricinus nymphal abundance x infection rate, at a given locality. Statistically significant cumulation of insect-history recalling patients into several, generally wetland, areas was ascertained; borreliae were revealed in 0.5% of the dipterans examined.

Animals↗

PubMed1997

Objective assessment of risk maps of tick-borne encephalitis and Lyme borreliosis based on spatial patterns of located cases.

BACKGROUND: Clusters of infection can indicate the underlying risk pattern of an endemic disease. Retrospective epidemiological data have been used to map the risk of tick-borne encephalitis (TBE) and Lyme borreliosis (LB) in the Central Bohemian region of the Czech Republic. METHODS: Both reported places of infection and patients' residences were entered in a geographical information system; their distance distribution and census data were used to model density of the population at risk. Point-pattern analysis and non-parametric kernel smoothing of points of infection were applied to compute the risk maps. Tick flagging and direct immunofluorescence assay were used to probe true LB-risk in the field. RESULTS: Tick-borne encephalitis infections proved to be more clustered than those of LB which was widespread; however, the most prominent clusters of both diseases largely correspond to each other. The estimated LB risk correlated well with tangible disease challenge as assessed from the tick abundance and Borrelia infection rates at 15 selected localities surveyed annually. CONCLUSION: The risk of LB is widely and smoothly distributed over the area studied, apparently following tick habitats wherever they occur, while TBE is confined to a subset of these locations.

Czech Republic↗

PubMed1990

Tolerance and cross-tolerance to stress-induced increases in plasma Met-enkephalin in rats with adaptively increased resting secretion.

Plasma concentrations of both native (pentapeptide plus its sulfoxide) and peptidase-derivable (trypsin followed by carboxypeptidase-B) Met-enkephalin showed brisk increases in response to the stresses of immobilization, hemorrhage, and electric footshock in conscious, freely moving, adult male rats. Daily exposure to 150-min periods of immobilization resulted in a maintained increase in baseline plasma concentrations of native Met-enkephalin 21.5 h after the sixth day and a further increase after 39 days. The plasma native Met-enkephalin response to acute immobilization was attenuated on day 7 and completely absent on day 40. Unstressed rats showed a plasma native Met-enkephalin response to hemorrhage of 15% blood volume and a further increase in response to 25% hemorrhage. Immediately after initial acute immobilization or 6 days of daily immobilization when plasma native Met-enkephalin was elevated but the response to acute immobilization was attenuated, plasma native Met-enkephalin responses to hemorrhage were also attenuated. Rats that had been immobilized daily for 40 days and showed no plasma native Met-enkephalin response to acute immobilization also showed no responses to hemorrhage. After 39 days of immobilization when there was no plasma native Met-enkephalin response to acute immobilization, there was also no response to footshock. Thus, development of tolerance or adaptive loss of plasma native Met-enkephalin response to immobilization with repeated exposure to this stressor is associated with cross-tolerance or adaptive loss of the responses to the stresses of hemorrhage or electric footshock. Development of tolerance and cross-tolerance of plasma responses of peptidase-derivable Met-enkephalin paralleled that of native Met-enkephalin. Thus, adaptation of plasma Met-enkephalin responses to repeated exposure to a stressor included both increased resting secretion and decreased acute responses to homotypic or novel stressors.

Adaptation, Physiological↗

PubMed1990

[Simultaneous occurrence of tick-borne encephalitis and Lyme borreliosis in the Central Bohemian Region].

An analysis of joint occurrence of tick-borne encephalitis and Lyme borreliosis in the Central Bohemian region of Czechoslovakia, based on clinical cases, showed a divergency in the dispersion patterns of the diseases. Whilst tick-borne encephalitis infections occurred in a few limited areas and its clinical cases tended to aggregate into well defined clusters, apparently following its natural focality, the cases of Lyme borreliosis were scattered +/- randomly over nearly all the region without forming such marked clusters and having little topographical correlation with tick-borne encephalitis. A computer model was applied to substantiate the observations.

Czechoslovakia↗

PubMed1990

[Possibilities of dialysis therapy in irreversible renal failure in rheumatoid arthritis with secondary amyloidosis].

The authors discuss their initial experience with the treatment of secondary amyloidosis in rheumatoid arthritis with irreversible renal failure in patients included in a regular dialyzation programme. The hitherto assembled 15-month experience justifies the inclusion of patients with this cause of irreversible renal failure in a dialyzation programme. The reverse is not only wrong from the medical aspect but is inhuman and interferes with the life of families of these patients. Although the procedure during a regular dialyzation programme of these patients with rheumatoid arthritis with secondary amyloidosis is more complicated, more pretentious and more responsible, it is our medical duty to carry this burden together with the patient.

Amyloidosis↗