Jana Zvárová

Essential hypertension in adolescents: Association with insulin resistance and with metabolism of homocysteine and vitamins

BACKGROUND Although insulin resistance and elevated plasma homocysteine are associated with hypertension in adults, the role of these conditions in the initial phase of hypertension is largely unknown. We examined whether insulin resistance and disturbed homocysteine metabolism are present in young adults at the early stages of essential hypertension. METHODS We measured physical characteristics, plasma levels of insulin, lipids, total homocysteine, and vitamins in 164 patients with essential juvenile hypertension (median age, 19 years; 92% males) and in 173 controls (median age, 18 years; 66% males). Furthermore, we analyzed the prevalence of six polymorphisms in four genes of the methionine cycle. RESULTS Patients with hypertension and controls differed significantly (P <.05) in body mass index, levels of insulin, high-density lipoprotein-cholesterol, fasting and post-load plasma homocysteine, and folates. Systolic blood pressure was correlated with homocysteine levels and inversely correlated with plasma folates. Logistic regression showed that fasting homocysteine, vitamin B(12), and low-density lipoprotein-cholesterol were associated with a significantly increased risk of juvenile hypertension. In contrast, the birth length, polymorphism c.2756 A-->G in the MTR gene and plasma folate were associated with a significantly decreased risk of juvenile hypertension. CONCLUSIONS Our study showed that essential hypertension in adolescents is associated with lower folate and higher homocysteine levels, and with signs of insulin resistance. These data suggest that hypertension in young individuals may be a part of early manifestation of insulin resistance syndrome, and that disturbed folate and homocysteine metabolism may play a role in the early stages of hypertension.

GUHA for personal computers

Abstract The GUHA method of automated hypotheses formation, whose paradigm is to generate automatically all interesting hypotheses supported by given data, has a rather long history and Tomas Havranek entered it in a very early stage of development in 1971. It is his achievement that GUHA has changed from a mainly logical method to a system of exploratory data analysis; and during years he contributed in a fundamental way to its advancement, both in the theoretical foundations and software projects. Here we present a short description of the current implementation of the most used GUHA procedure ASSOC.

Genetic variants of homocysteine metabolizing enzymes and the risk of coronary artery disease.

It is unresolved whether elevated homocysteine in coronary artery disease (CAD) is the cause of arteriosclerosis or its consequence. In contrast, genetic variants of enzymes that metabolize homocysteine cannot be altered by arteriosclerosis. Consequently, their association with CAD would permit to imply causality. We modeled by regression analysis the effect of 11 variants in the methionine cycle upon CAD manifestation in 591 controls and 278 CAD patients. Among the examined variants only the carriership for the c.844ins68 in the cystathionine beta-synthase (CBS) gene was associated with a significantly lowered risk of CAD (OR=0.56; 95% CI=0.35-0.90 in the univariable, and OR=0.41, 95% CI=0.19-0.89 for obese people in the multivariable analysis, respectively). Healthy carriers of the c.844ins68 variant exhibited, compared to the wild type controls, significantly higher postload ratios of blood S-adenosylmethionine to S-adenosylhomocysteine (61.4 vs. 54.9, p=0.001) and of plasma total cysteine to homocysteine (8.6 vs. 7.3, p=0.004). The changes in these metabolites are compatible with an improved methylation status and with enhanced activity of homocysteine transsulfuration. In conclusion, the coincidence of clinical and biochemical effects of a common c.844ins68 CBS variant supports the hypothesis that compounds relating to homocysteine metabolism may play role in the development and/or progression of CAD.

Explaining the decline in coronary heart disease mortality in the Czech Republic between 1985 and 2007

Background Coronary heart disease (CHD) mortality has declined substantially in the Czech Republic over the last two decades. Design The purpose of this study was to determine what proportion of this CHD mortality decline could be associated with temporal trends in major CHD risk factors and what proportion with advances in medical and surgical treatments. Methods The validated IMPACT mortality model was used to combine and analyse data on uptake and effectiveness of CHD management and risk factor trends in the Czech Republic in adults aged 25–74 years between 1985 and 2007. The main sources were official statistics, national quality of care registries, published trials and meta-analyses, and the Czech MONICA and Czech post-MONICA studies. Results Between 1985 and 2007, age-adjusted CHD mortality rates in the Czech Republic decreased by 66.2% in men and 65.4% in women in the age group 25–74 years, representing 12,080 fewer CHD deaths in 2007. Changes in CHD risk factors explained approximately 52% of the total mortality decrease, and improvements in medical treatments approximately 43%. Increases in body mass index and in diabetes prevalence had a negative impact, increasing CHD mortality by approximately 1% and 5%, respectively. Conclusions More than half of the very substantial fall in CHD mortality in the Czech Republic between 1985 and 2007 was attributable to reduction in major cardiovascular risk factors. Improvement in treatments accounted for approximately 43% of the total mortality decrease. These findings emphasize the value of primary prevention and evidence-based medical treatment.

Medical guidelines presentation and comparing with Electronic Health Record.

Electronic Health Record (EHR) systems are now being developed in many places. More advanced systems provide also reminder facilities, usually based on if-then rules. In this paper we propose a method how to build the reminder facility directly upon the guideline interchange format (GLIF) model of medical guidelines. The method compares data items on the input of EHR system with medical guidelines GLIF model and is able to reveal if the input data item, that represents patient diagnosis or proposed patient treatment, contradicts with medical guidelines or not. The reminder facility can be part of EHR system itself or it can be realized by a stand-alone reminder system (SRS). The possible architecture of stand-alone reminder system is described in this paper and the advantages of stand-alone solution are discussed. The part of the EHR system could be also a browser that would present graphical GLIF model in easy to understand manner on the user screen. This browser can be data driven and focus attention of user to the relevant part of medical guidelines GLIF model.

Effect of polychlorinated biphenyls (PCBs) and 1,1,1-trichloro-2,2,-bis (4-chlorophenyl)-ethane (DDT) in follicular fluid on the results of in vitro fertilization–embryo transfer (IVF-ET) programs

OBJECTIVE To establish the effect of chlorinated organic compounds on fertility. DESIGN We analyzed the influence of polychlorinated biphenyls (PCBs) and pesticides in follicular fluid on the number of fertilized oocytes, the quality of oocytes and embryos, pregnancy rate, and number of embryos cryoconserved in IVF-ET program. SETTING Department of Gynecology and Obstetrics, Charles University, First Faculty of Medicine and General Teaching Hospital, Prague, Czech Republic. PATIENT(S) Patients from the Center of Assisted Reproduction. INTERVENTION(S) We collected the follicular fluid of 99 infertile women. MAIN OUTCOME MEASURE(S) The levels of xenobiotics in follicular fluid were examined by high-resolution mass spectrometry and gas chromatography. Correlations between the levels of xenobiotics and IVF-ET program results were statistically analyzed. RESULT(S) The PCB levels varied from 0.1 to 254.6 ng/g of fat. Levels of DDT and its metabolites varied from 0.3 to 35 228.8 ng/g of fat. A correlation was found between the number of diploid oocytes and the level of DDT, the fertilization of oocytes and level of PCB 158, and the pregnancy rate and the number of embryos cryoconserved and levels of PCB 47. CONCLUSION(S) Xenobiotics can be detected in the fat compartment of the follicular fluid. Some correlation to the IVF-ET program results was established, to a degree that might be considered of concern, although it was not statistically significant at the 5% level.

Information theoretical approach to constitution and reduction of medical data

In medical decision problems it is very important to use the most relevant piece of information for decision making. We focus on a special case of diagnostic decision making when we can measure many symptoms and signs and we have to make diagnostic conclusions. We can state the problem as follows. We can measure symptoms and signs of a patient, denoted by s1, s2, ..., sk, and we have to decide about a possible diagnosis d. We know that the symptoms and signs have different costs w1, w2, ... wk when they are examined. Of course, each symptom, sign or their combination has a different predictive value for the diagnosis. Our task is to find out the combination of symptoms from given data with a sufficient informative value for diagnostic decision making. However, simultaneously we look for a combination of symptoms and signs with minimal costs among those carrying sufficient information. For that reason we will describe approaches based on information measures of statistical dependence and to show the idea of the program CORE (constitution and reduction of data) prepared for practical applications in medicine.

Phenytoin as a risk factor in gingival hyperplasia

Summary Fifty-four out-patients with epilepsy who had been taking phenytoin for more than one year were examined for gingival hyperplasia. Approximately 76% of patients showed either mild or no gingival hyperplasia. Lesion severity was then compared statistically to phenytoin dosage and drug concentrations as well as to other clinical and laboratory parameters. There was a tendency for gingival hypertrophy to be associated with both increasing dosage of phenytoin per unit of body weight and the duration of phenytoin administration. All patients followed had a statistically significant progressive trend to increasing gingival hyperplasia with higher total and free phenytoin concentration.

On the medical informatics structure

This paper contributes to the discussion of R. Haux paper on essential aims and tasks of medical informatics. New views on structure of informatics and consequently medical informatics are given. Information is introduced as outside and inside information. Inside information is divided into three different types as data, evidence and knowledge. This terminology slightly differs from the commonly used terminology data, information and knowledge. Based on understanding of information as outside and inside information the field of informatics is divided into four rings, namely Information Basic Ring, Information Methodology Ring, Information Interface Ring and Information Technology Ring. Medical informatics is defined and its structure explained using four information rings. These views on informatics and medical informatics open possibilities to see more clearly where are the essential aims and tasks of medical informatics.

Electronic Health Record for Forensic Dentistry

OBJECTIVES To identify support of structured data entry for electronic health record application in forensic dentistry. METHODS The methods of structuring information in dentistry are described and validation of structured data entry in electronic health records for forensic dentistry is performed on several real cases with the interactive DentCross component. The connection of this component to MUDR and MUDRLite electronic health records is described. RESULTS The use of the electronic health record MUDRLite and the interactive DentCross component to collect dental information required by standardized Disaster Victim Identification Form by Interpol for possible victim identification is shown. CONCLUSIONS The analysis of structured data entry for dentistry using the DentCross component connected to an electronic health record showed the practical ability of the DentCross component to deliver a real service to dental care and the ability to support the identification of a person in forensic dentistry.