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Biomedical subjects

J Zvárová

Publications and source records attributed to J Zvárová.

At least 19 recordsLinked to original sources
PubMed2007

The Framingham risk function underestimated absolute coronary heart disease risk in Czech men.

OBJECTIVES: The aim was to validate the Framingham coronary heart disease (CHD) risk function with the formula by Wilson et al. (1998) in Czech men. METHODS: The validation was performed within the 20-year primary prevention study of atherosclerotic risk factors (STULONG) including 1417 middle-aged men from the Czech Republic (Prague). A total of 646 men examined in 1979-1988, and followed-up for ten years, were included into the validation study. The calibration and discrimination ability of the Framingham risk function in the Czech population were explored. RESULTS: The estimated 10-year risk of CHD by the Framingham risk function was 12.8% in 646 men, significantly higher than the observed risk (16.4 %), p = 0.013. The trend in the 10-year incidence of CHD was significantly increasing with quintiles of the estimated risk, p < 0.001. After the recalibration of the Framingham risk function, there was an insignificant difference between the estimated (18.2%) and observed (16.4%) risks of CHD, p = 0.320. The Framingham risk function classified men into those with and without CHD in the 10-year period with accuracy over 60%. CONCLUSIONS: Unlike some validation studies from Western Europe, the Framingham risk function significantly underestimated the 10-year CHD risk in the Czech Republic. In agreement with these studies, the incidence of CHD was significantly increasing across quintiles of the estimated risk.

Adult↗
PubMed2006

Comparison of FK 506, mycophenolate mofetil, and aminoguanidine effects on delay of corneal allograft rejection in an experimental model of low-risk and high-risk keratoplasty.

The purpose of our study was to compare the effectiveness of immunosuppressive drugs on the prevention of allograft rejection in a murine model of low-risk and high-risk keratoplasty. The therapy included FK 506 (tacrolimus; 0.2 mg/kg), mycophenolate mofetil (30 mg/kg), aminoguanidine (0.1 g/kg), and combination of FK506 + mycophenolate mofetil or FK506 + aminoguanidine. The results obtained from the Gray's survival model stratified according to the type of subjects suggest that a major rejection risk reduction was achieved using FK506; good results also were obtained for mycophenolate mofetil. Although the point estimates of both the survival and relative risk of rejection suggest a deferred effect of the combination FK506 + mycophenolate mofetil, this finding did not prove statistically significant.

Animals↗
PubMed2006

On genetic information, diversity and distance.

OBJECTIVES: General information-theoretic concepts such as f-divergence, f-information and f-entropy are applied to the genetic models where genes are characterized by randomly distributed alleles. The paper thus presents an information-theoretic background for measuring genetic distances between populations, genetic information in various observations on individuals about their alleles and, finally, genetic diversities in various populations. METHODS: Genetic distances were derived as divergences between frequencies of alleles representing a gene in two different populations. Genetic information was derived as a measure of statistical association between the observations taken on individuals and the alleles of these individuals. Genetic diversities were derived from divergences and information. RESULTS: The concept of genetic f-information introduced in the paper seems to be new. We show that the measures of genetic distance and diversity used in the previous literature are special cases of the genetic f-divergence and f-diversity introduced in the paper and illustrated by examples. We also display intimate connections between the genetic f-information and the genetic f-divergence on one side and genetic f-diversity on the other side. The examples at the same time also illustrate practical computations and applications of the important concepts of quantitative genetics introduced in the paper. CONCLUSIONS: We discussed a general class of f- divergence measures that are suitable measures of genetic distance between populations characterized by concrete frequencies of alleles. We have shown that a wide class of genetic information, called f-information, can be obtained from f-divergences and that a wide class of measures of genetic diversity, called f-diversities, can be obtained from the f-divergences and f-information.

Databases, Genetic↗
PubMed2006

The new features of the ExaMe evaluation system and reliability of its fixed tests.

OBJECTIVES: The ExaMe system for the evaluation of targeted knowledge has been in development since 1998. The new features of the ExaMe system are introduced in this paper. Especially, the new three-layer architecture is described. Besides the system itself, the properties of fixed tests in the ExaMe system are studied. In special detail, the reliability of the fixed tests is discussed. The theory background is explained and some limitations of the reliability are pointed out. METHODS FOR ESTIMATION OF THE RELIABILITY: Three characteristics used for estimation of reliability of educational tests are discussed: Cronbach's alpha, standardized item alpha and split half coefficient. The relation between these characteristics and reliability and between characteristics themselves is investigated. In more detail, the properties of Cronbach's alpha, the characteristics mostly used for the estimation of reliability, are discussed. A confidence interval is introduced for the characteristics. RESULTS AND CONCLUSIONS: Since 2000, the serviceability of the ExaMe evaluation system as the supporting evaluation tool has been repeatedly shown at the courses of Ph.D. studies in biomedical informatics at Charles University in Prague. The ExaMe system also opens new possibilities for self-evaluation and distance learning, especially when connected with electronic books on the Internet. The estimation of reliability of tests contains some limitations. Keeping them in mind, we can still get some information about the quality of certain educational tests. Therefore, the estimation of reliability of the fixed tests is implemented in the ExaMe system.

Czech Republic↗
PubMed2006

[Primary prevention of ischemic heart disease in middle-aged men living in Prague: results of twenty-year research].

INTRODUCTION: Ischemic Heart Disease (IHD) represents the most frequent cause of mortality and morbidity in the Czech Republic. The aim of this study is to analyze long-term mortality of cardiovascular disease (CVD), identify its predictors and verify the validity of Framingham risk function for Czech patients. DESIGN AND METHODS: The twenty-year study (STULONG) of primary prevention of risk factors of atherosclerosis in 1419 men aged 38 to 53 years living in Prague was started in 1975. RESULTS: CVD mortality analysis showed a higher risk of death for heavy smokers vs. non-smokers or light smokers (p < 0.0001), hypertensive patients vs. patients with normal blood pressure (p < 0.0001), men with hypercholesterolemia vs. men with normal cholesterol level (p = 0.0432), and a lower risk for university graduates vs. men with elementary education (p = 0.0006). Between 1980 and 1984, age-specific CVD mortality rates of men from STULONG study were higher (p = 0.0132) than national CVD mortality rates; between 1985 and 1994, they were insignificantly lower. Framingham risk function underestimated absolute ten-year risk of IHD in all risk quintiles (p < 0.0001) with discrimination of 63%. CONCLUSION: CVD mortality observed within STULONG study was significantly affected by known risk factors (hypertension, smoking, hypercholesterolemia, lower education); Framingham risk function underestimated absolute ten-year risk of IHD.

Coronary Artery Disease↗
PubMed2006

[Intrapartal fetal monitoring, sensitivity and specificity of methods].

OBJECTIVE: To evaluated sensitivity and specificity of presently used methods for intrapartal monitoring (CTG, FpO2 a STAN S-21) and their mutual comparison. TYPE OF STUDY: A prospective study. SETTING: Gynecological-Obstetrical Clinic, 1st Medical Faculty, Charles University and general Teaching Hospital, Prague. METHOD: In 114 pregnant women with high-risk or pathological course of pregnancy the authors evaluated the capability of individual methods to predict intrapartal hypoxia, determined on the basis of postnatal evaluation of parameters observed (Apgar score in 1st minute, pH from umbilical artery, lactate levels in fetal blood, base excess (BE) and postpartum condition of fetus evaluated by a neonatologist). Each method was categorized according to its importance. The quality of individual methods was evaluated by means of their sensitivity and specificity as well as by the area under ROC (Receiver Operating Characteristic), i.e. AUC (Area under Curve). A similar or different prediction of the condition of the newborn by these individual methods was evaluated by the McNamara test of symmetry. In 50 deliveries performed by Cesarean section and 24 forceps deliveries the authors evaluated postnatal pH from umbilical artery and evaluation by Chi-square test. The women in childbed were infused with a tocolytic drug (hexoprenalin) before Cesarean section. All tests were performed at 5% level of significance. RESULTS: Low level of Apgar score in the 1st minute and less) always indicated CTG, but also a large proportion of normal newborns. STAN, in contrast, well indicates all newborns with a normal point evaluation. The best balanced evaluation of the newborns is provided by FpO2 and there was a significant difference between CTG and FpO2. In evaluating pH from the umbilical artery (pH < 7.20), TCG proved to be most sensitive again but displayed low specificity. STAN was the best predictor of newborns with normal pH. In evaluating high levels of lactate (> 3.7mmol/L) and BE (> -10) and related demonstration of metabolic acidosis STAN proved to be the best predictor. The condition of the newborn evaluated by a neonatologist immediately after birth (medium or heavy depression) was best predicted by FpO2. In deliveries performed by Cesarean section and after the administration of tocolysis the postnatal pH was higher then in forceps deliveries without acute tocolysis. The occurrence of emergencies in the course of a pathological delivery in individual methods is as follows: CTG, FpO2 and STAN. CONCLUSION: Even though CTG displays a very low specificity, this method should not be rejected, since it draws attention of the obstetrician very early to the possibility of developing hypoxia. FpO2 or STAN gives more precision to the situation and demarcates a correct moment for ending the delivery for the indication of fetus hypoxia intra partum. STAN is the best predictor for conditions of developing metabolic acidosis, evaluated postnatally by the level of lactate and BE in fetal blood.

Apgar Score↗
PubMed2006

Triangulation applied to Jan H. van Bemmel.

OBJECTIVE: To describe the person of Jan H. van Bemmel from different points of view. METHOD: Triangulation. RESULTS AND CONCLUSIONS: Jan H. van Bemmel successfully contributed to research and education in medical informatics. He inspired a lot of people in The Netherlands and internationally.

Biomedical Research↗
PubMed2005

Primary prevention of coronary artery disease among middle aged men in Prague: twenty-year follow-up results.

BACKGROUND: Coronary artery disease (CAD) represents the most common cause of morbidity and mortality in the Czech Republic. The aim of this study is to analyze long-term cardiovascular diseases (CVD) mortality, identify predictors of outcome and to validate the Framingham risk function in men from the Czech Republic. DESIGN AND METHODS: A 20-year primary prevention study of atherosclerosis risk factors in 1417 men from Prague aged 38-53 years was launched in 1975 (STULONG). RESULTS: When analyzing CVD mortality, heavy smokers had hazard higher than non-smokers and light smokers (p < 0.0001); hypertensives higher than normotensives (p < 0.0001); men with hypercholesterolemia higher than those with normal cholesterol (p = 0.0432), and university-educated men lower than elementary-educated men (p = 0.0006). In 1980-1984, the age specific mortality from CVD in men from STULONG was higher (p = 0.0132) than in the Czech Republic, in 1985-1994 insignificantly lower. The Framingham risk function underestimated the absolute 10-year risk of CAD across the quintile of the risk (p < 0.0001), with 63% discrimination. CONCLUSION: In STULONG, the mortality from CVD was significantly associated with known risk factors (hypertension, smoking, hypercholesterolemia, education); the Framingham risk function underestimated the absolute 10-year risk of CAD.

Adult↗
PubMed2005

Effects of inhibition of urokinase-type plasminogen activator (u-PA) by amiloride in the cornea and tear fluid of eyes irradiated with UVB.

The purpose of the present study was to test our hypothesis that amiloride, a specific u-PA inhibitor, effectively decreases u-PA activity in cornea as well as in tear fluid and favourably affects corneal healing. Therefore, comparative histochemical and biochemical studies of u-PA and the effects of amiloride were performed on rabbit corneas and tear fluid using the sensitive fluorogenic substrate Z-Gly-Gly-Arg-7-amino-4-trifluoromethylcoumarin. Rabbit eyes were repeatedly irradiated with UVB for 9 days and during the irradiation topically treated with amiloride (1 mg/ml saline) or placebo (saline) (dropwise, 5 times daily). Results show that in placebo-treated eyes, UVB evoked the appearance of u-PA activity in cornea and tear fluid in early stages of irradiation, and u-PA levels increased during irradiation. Corneal epithelium was gradually lost and remnants of the epithelium as well as keratocytes in the upper part of corneal stroma showed high u-PA activity. Finally, corneas lost their epithelium completely. In corneal stroma, numerous u-PA-containing inflammatory cells were present. Corneas were vascularized. When amiloride was dropped on the eye surface on the first day of irradiation and subsequently daily until the end of the experiment, u-PA activity in both cornea and tear fluid was strongly inhibited. Corneas were covered with a continuous epithelium until the end of the experiment. The number of inflammatory cells was significantly decreased. Corneal vascularization was reduced by 50%. In conclusion, early application of amiloride inhibited u-PA activity in UVB-irradiated corneas as well as in tear fluid and diminished the development of corneal pathology.

Amiloride↗
PubMed2005

Genetic determinants of folate status in Central Bohemia.

Although several genetic factors have been implicated as determinants of blood folate concentration in various populations, their effect on folate status in the Czech population has not yet been examined. We explored whether blood folate concentrations in healthy Czech population are associated with polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR), folate hydrolase 1 (FOLH1), reduced folate carrier (RFC), and folate receptor (FOLR1) genes. In a cross-sectional study of 591 control subjects we determined genotypes by PCR-RFLP or ARMS-PCR methods, and plasma and erythrocyte folates by MEIA. The effect of different genotypes on folate status was examined by non-parametric tests and by regression analysis. The prevalence of the MTHFR 677C>T, MTHFR 1298A>C, FOLH1 1561C>T, RFC 80G>A and FOLR1 480G>C variant alleles was 0.34, 0.33, 0.05, 0.44 and 0.00, respectively. Only the MTHFR 677C>T variant was significantly associated with plasma folate concentrations (median 14.7, 14.0 and 12.2 nmol/l for the CC, CT and TT genotypes, respectively). Our study showed that among the five studied allelic variants, only the 677C>T polymorphism in the MTHFR gene is a significant genetic determinant of plasma folate concentrations in Czech population.

Aryl Hydrocarbon Hydroxylases↗
PubMed2005

[Analysis of present diagnostic methods of intrapartum fetal hypoxia].

OBJECTIVE: To evaluate specificity of present diagnostic methods of intrapartal fetal hypoxia (cardiotocography--CTG, fetal pulse oxymetry--FpO2, ST-ECG analysis). DESIGN: A prospective study. SETTING: Gynecology-Obstetrics Clinic, 1st Medical Faculty and General Faculty Hospital in Prague. METHODS: The results of synchronic fetus monitoring by means of CTG, FpO2 and STAN-ST 21 were followed in 53 mothers with a risk and pathological delivering of birth in the period of April 2003 to March 2004. The study investigated, which of the methods provided the best prediction of the intrapartal fetal hypoxia. The statistical evaluation (p-mark test and Mc Namara test) was based on the assessment of correct or incorrect prediction of the Apgar score values in the first minute after birth, pH in umbilical artery and the lactate level. We also investigated results of three methods during postpartum depression, turbid or mushy amniotic fluid and the way the individual methods were made useful in indication for ending the delivery. RESULTS: In comparison with CTG there was a statistically significantly higher specificity in FpO2 and STAN in the evaluation of Apgar score in the newborn in the first minute after birth, FpO2 (p=0.007) and STAN-ST (p<0.001), in the determination of pH (a) from umbilical blood FpO2 (p=0.029) and STAN (p=0.001) and the occurrence of postpartum depression of the newborn in minute 30-60 after birth FpO2 (p=0.019) and STAN (p=0.0005). The changes in lactate level in umbilical blood were better predicated by STAN (p=0.001). FpO2 evaluated the changes in the same way as CTG. The threatening hypoxia in strongly turbid or even mushy amniotic fluid was correctly evaluated by STAN only (p=0.002). The FpO2 evaluation was not statistically significant. There was not any statistically significant difference in the indication of operation for ending the delivery among the individual methods. CONCLUSIONS: The results univocally demonstrated that the used of other method for diagnosis on intrapartal fetus hypoxia--Fetal pulse oxymetry and ST--analysis of ECG of the fetus give more precision to the diagnosis. The introduction of these methods requires a correct interpretation and the effort of the obstetrician to use these methods in clinical practice.

Adult↗
PubMed2005

[Differences in the polychlorinated biphenyl levels in follicular fluid in individual types of sterility].

OBJECTIVE: To find the differences of polychlorinated biphenyls (PCBs) levels in follicular fluid in different indications to treatment with IVF + ET program. 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, Prague, Euromise Centrum, Charles University and Academy of Art, Prague. METHODS: We examinated 100 infertile women undergoing IVF + ET program in our pilot study. After ovarian pick-up, frozen follicular fluid were transported to the laboratory. We detected the levels of polychlorinated biphenyls in follicular fluid of infertile women. The levels were compared according to the different indications of treatment. The control group consist of patients with male factor of sterility. RESULTS: We confirmed the higher levels of PCB 114, 153, 156, 157, 180 and 189 in indication endometriosis compared with the others and with control group. The levels of PCBs were in ng/gram of fat. CONCLUSION: It has become apparent that higher levels of PCB 114, 153, 156, 157, 180 and 189 in endometriosis patients may be one of many factors participating in the origin of the disease.

Adult↗
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

New approaches to health promotion and informatics education using Internet in the Czech Republic.

The paper describes nowadays information technology skills in the Czech Republic. It focuses on informatics education using Internet, ECDL concept and the links between computer literacy among health care professionals and quality of health care. Everyone understands that the main source of wealth of any nation is information management and the efficient transformation of information into knowledge. There appear completely new decisive factors for the economics of the near future based on circulation and exchange information. It is clear that modern health care cannot be built without information and communication technologies. We discuss several approaches how to contribute to some topics of information society in health care, namely the role of electronic health record, structured information, extraction of information from free medical texts and sharing knowledge stored in medical guidelines.

Health Promotion↗
PubMed2004

Synergy between medical informatics and bioinformatics: facilitating genomic medicine for future health care.

In this paper, we review the results of BIOINFOMED, a study funded by the European Commission (EC) with the purpose to analyse the different issues and challenges in the area where Medical Informatics and Bioinformatics meet. Traditionally, Medical Informatics has been focused on the intersection between computer science and clinical medicine, whereas Bioinformatics have been predominantly centered on the intersection between computer science and biological research. Although researchers from both areas have occasionally collaborated, their training, objectives and interests have been quite different. The results of the Human Genome and related projects have attracted the interest of many professionals, and introduced new challenges that will transform biomedical research and health care. A characteristic of the 'post genomic' era will be to correlate essential genotypic information with expressed phenotypic information. In this context, Biomedical Informatics (BMI) has emerged to describe the technology that brings both disciplines (BI and MI) together to support genomic medicine. In recognition of the dynamic nature of BMI, institutions such as the EC have launched several initiatives in support of a research agenda, including the BIOINFOMED study.

Biotechnology↗
PubMed2004

[Gastrointestinal tract cancer and diabetes mellitus].

Risk of development of some gastrointestinal tract cancers (colorectal cancer, pancreas cancer and liver cancer) is higher in type II diabetics. Another important risk factor is obesity (for gall bladder cancer in women and in men also for stomach and esophageal cancer). Pathogenetic factors have been explored especially in colorectal cancer (diet, hyperinsulinaemia, metabolic receptors activation, absence of physical activity). Our Czech study also proved up to 4 times increased risk of colorectal cancer in diabetics and, in accordance with literature, probable influence of persistent diabetes on tumour development. Type II diabetes mellitus should be considered as a risk factor especially for colorectal cancer, liver cancer, and pancreas cancer. In type I diabetics no risk of gastrointestinal tract cancers was proved.

Colorectal Neoplasms↗