PubMed Health⌕ Search

Biomedical subjects

K Zvára

Publications and source records attributed to K Zvára.

9 recordsLinked to original sources
PubMed2001

Decrease of psychomotor performance in subjects with latent 'asymptomatic' toxoplasmosis.

Toxoplasma gondii is known to induce specific behavioural changes in its intermediate hosts. This is usually considered to be an evolutionary adaptation aimed to increase the probability of transmission of the parasite into its definitive host, the cat, by predation. In rodents an increase of reaction time as well as many other specific behavioural patterns have been observed. Here we report the results of our double blind study showing the significantly longer reaction times of 60 subjects with latent toxoplasmosis in comparison with those of 56 controls. Moreover, the existence of a positive correlation between length of infection and mean reaction time suggested that slow and cumulative effects of latent toxoplasmosis rather than a one-step (and possibly transient) effect of acute toxoplasmosis disease are responsible for the decrease of psychomotor performance of infected subjects. To our knowledge, this is the first study confirming the existence of such parasite-induced changes in human behaviour that could be considered in evolutionary history of the human species as adaptive from the point of view of parasite transmission.

Animals↗
PubMed2000

Evaluation of knowledge using ExaMe program on the Internet.

In the paper we describe the function of the ExaMe program that serves for evaluation of students' knowledge using Internet. Evaluation is based on the knowledge base of a given course. Two types of evaluation tests are described. The fixed test is appropriate for examination of students by the teacher in computer classroom connected to Internet. By this test the evaluation is done in the limited time period and all students are tested with the same evaluation test. The automatic test is appropriate for self-evaluation and self-study by students on remote places. The student can ask the ExaMe program for the test of different difficulty levels and state the number of questions required. Finally thee first experience with the ExaMe program in practice is given.

Education, Distance↗
PubMed1999

Evaluation of medical knowledge using electronic textbooks and ExaMe program on Internet.

In the paper we describe the function of the ExaMe program that serves for evaluation of students knowledge using Internet. Evaluation is based on the knowledge base of a given course. Two types of evaluation tests are described. The fixed test is appropriate for examination of students by the teacher in computer classroom connected to Internet. By this test the evaluation is done in the limited time period and all students are tested with the same evaluation test. The automatic test is appropriate for self-evaluation and self-study by students on remote places. The student can ask the ExaMe program for the test of different difficulty levels and state the number of questions required. Finally the first experience with the ExaMe program in practice is given. The application of the ExaMe program is shown in connection with IT EDUCTRA electronic products and electronic textbook on biomedical statistics.

Computer-Assisted Instruction↗
PubMed1998

Heteroxenous coccidia increase the predation risk of parasitized rodents.

We have investigated the influence of heteroxenous coccidia (Apicomplexa: Eimeriorina) on the predation risk of intermediate hosts. Voles infected with Frenkelia spp. were found more frequently in buzzards' (Buteo buteo) prey than among snap-trapped rodents. To eliminate the possibility of traps selecting for uninfected rodents, a laboratory experiment was performed. Mice experimentally infected with Sarcocystis dispersa seemed to be more likely caught by the final host, the long-eared owl (Asio otus); this result was confirmed by a mathematical model. Field data confirmed the adaptive value of parasite-induced changes. The increase of predation is directed towards the specific final host only or is non-specific. In the populations studied the probability of predation of parasitized individuals by the specific predator was increased.

Animals↗
PubMed1997

Decision support and data analysis tools for risk assessment in primary preventive study of atherosclerosis.

In the paper we show results of two programs applied for data analysis and decision support in primary preventive study of atherosclerosis. First program E.T. (Epidemiology Tools) can be used for analysis of data from retrospective (case-control) studies, prospective (cohort) studies and for standardization. Second program called CORE (COnstitution and REduction) supports the process of selection of features that are relevant for given decision making task. Program CORE is using information theory approach. Both these programs were applied to analysis of data about 1417 middle age men collected in the longitudinal study on atherosclerosis in urban population. Apart from these two new programs we have analyzed data also by the STATISTICA software.

Adult↗
PubMed1993

Quantitative analysis of drug handling by the kidney using a physiological model of renal drug clearance.

Published data on the renal clearance of creatinine, p-aminohippuric acid (PAH) and kanamycin in relation to glomerular filtration rate (GFR) in patients with various renal diseases were analysed by a physiological model of renal clearance. Fitting of the data by the general linear equation representing the model proposed by Levy [10] resulted in insignificant intercepts with the ordinate, indicating the unsuitability of the model for the detection of tubular secretory activity. Use of this model also did not lead to significant improvement in goodness of fit compared to simple proportionality of renal clearance and GFR. On the other hand, parameter estimates of the physiological model obtained from the data by nonlinear regression analysis revealed statistically significant tubular secretion both of PAH and creatinine. The much lower tubular secretory activity estimated from the kanamycin data did not reach statistical significance. For compounds exhibiting statistically significant tubular secretion, use of the physiologically based relationship between renal clearance and GFR significantly improved the goodness of fit to the data as compared to simple proportionality of both variables. It is concluded that analysis of the relationship between renal clearance of drugs and GFR using the physiological model of renal clearance can contribute to our knowledge of drug handling by the kidney, and may facilitate drug classification according to total extraction by this organ.

Aminohippuric Acids↗
PubMed1991

Computer-based evaluation of antibiotic therapy predictions.

Planning antibiotic treatment according to the given data on patients and results of microbiological examinations are important decision-making goals for physicians. One approach using a computer in medical education to improve the teaching process in this respect is described in this paper. On the basis of data about real patients and the optimal antibiotic treatment validated by the antibiotic center of the Faculty Hospital II, we can evaluate the student's abilities to predict correct antibiotic treatment. The general program written for this task and the method of evaluating the student's predictive skills are described.

Anti-Bacterial Agents↗
PubMed1982

Age correlation of alpha-2-macroglobulin levels in healthy subjects.

Groups of 336 female and 310 male subjects from the age of 11 years to 94 and 86 years respectively were examined by radial immunodiffusion for their alpha-2-macroglobulin ( A 2M ) levels. Both groups were subjected to regression analysis, using a third degree polynomial, and the equations of the curves giving the best fit for the observed distribution of the values in relation to age were computed. The implications of the results for biology and medicine are discussed.

Adolescent↗