Statistical approaches for evaluation of genetic risk factor of peripheral arterial occlusive disease

In the paper we show results of medical study from statistical point of view. The medical study was aimed to study genetic risk factors of peripheral arterial occlusive diseases in Czech population. Two genes, CBS and MTHFR were examined, as various genotypes of these genes are thought to have impact on amino thiols, who participate in variety of reactions in vasculature. Statistical part of the study was responsible for analysis and interpretation of collected data.

Serum ferritin levels in subjects at high risk of atherosclerosis

Serum ferritin levels were determined in a group of 148 subjects drawn from a community study who were found to be at high risk of atherosclerosis (evaluated on the basis of the following data: levels of non-HDL cholesterol, arterial pressure, smoking status, cardiovascular or cerebrovascular disease in a subject's history, diabetes mellitus, a positive family predisposition to, or accumulation of the above factors) and compared with the levels obtained in a control group of 148 examined age- and sex-matched subjects from the same community with non-significant risk factors. Mean serum ferritin levels were higher in the whole risk group and in the subgroups of risk men and postmenopausal women than in the corresponding controls (the whole risk group: 263.4 +/- 218.5 micrograms/l vs. 198.3 +/- 179.5 micrograms/l, p < 0.05; the subgroup of men 361.8 +/- 235.7 micrograms/l vs. 286.4 +/- 194.6 micrograms/l, p < 0.05 and the subgroup of postmenopausal women 184.1 +/- 143.1 vs. 126.7 +/- 108.4 micrograms/l, p < 0.05).

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.

[Sonographic measurement of intimal thickness of the common carotid artery in diabetics]

Incidence of atherosclerotic cardiovascular diseases in diabetics is known to be 2-4 times higher than in nondiabetic subjects. Intima-media-thickness of common carotid artery (IMT ACC) measured by B-mode sonography positively correlates with the severity of atherosclerotic changes in coronary arteries. This study compares sonographically assessed IMT ACC in patients with type 2 diabetes mellitus (27 patients, mean age 66.57 +/- 6.06 years) vs. 66 nondiabetic subjects (mean age 63.58 +/- 9.09 years). Intima-media thickness in diabetics was significantly higher when compared with the control group (0.826 +/- 0.29 mm vs. 0.647 +/- 0.26 mm). In the whole cohort of investigated subjects IMT ACC positively correlates with age. When adjusted for age, the mean IMT ACC level was significantly higher in men than in women.

Relevant information for decision support systems: application in cardiology

In the paper we show information theory tools for extracting relevant information for decision support systems from medical databases. Each proposed algorithm for selecting a set of relevant features has a specific score function defined by means of information-theoretical characteristics. Then algorithms are classified according to the primary criterion, that can lead to influence-preferring algorithms or weight-preferring algorithms. Other type of classification can be based on the way of selecting of features as forward, backward or combined algorithms. The software package called CORE (COnstitution and REduction) that supports the process of selection of features relevant for a decision making problem is described. Application on data about 1417 middle age men collected in the twenty years lasting interventional study of cardiovascular risk factors in middle aged men and for decision support in primary care are shown. However, the methodology presented is applicable for any decision making problem where extracting relevant information from data is required.

Comparative histochemical and biochemical studies on acid beta-galactosidase activity in the experimentally injured rabbit cornea and tear fluid using the sensitive substrate beta-galactoside-4-trifluoromethylumbelliferyl (HFC)

Comparative histochemical and biochemical studies on acid beta-galactosidase activity in the rabbit eye after various experimental injuries were performed using the same sensitive fluorogenic substrate beta-galactoside-4-trifluoromethylumbelliferyl (HFC). The aim of the study was to examine whether the severity of corneal damage corresponds with the level of the enzyme activity in the tear fluid. As until recently the substrate beta-galactoside-4-HFC had not been used for the histochemical detection of acid beta-galactosidase in the cornea, results obtained with this substrate in a fluorescent method were compared in parallel cryostat sections with results obtained using the substrate 5-bromo-4-chloro-3-indoxyl beta-galactoside in the indigogenic method (previously shown to be very sensitive for the detection of acid beta-galactosidase activity in the cornea). Both methods revealed similar localization and changes in enzyme activity; using beta-galactoside-4-HFC an acceptable cellular localization was achieved. For the measurement of acid beta-galactosidase activity in the tear fluid a semiquantitative biochemical method was elaborated using filter paper punches with the substrate (beta-galactoside-4-HFC) soaked with tears and incubated at 37 degrees C. The time of the first appearance of a greenish-yellow fluorescence (enzyme positivity) was recorded by UV lamp and compared with the appearance of fluorescence in calibrated punches containing known acid beta-galactosidase activities. The results show that beta-galactoside-4-HFC is useful for the biochemical assessment of acid beta-galactosidase activity in the tear fluid. Comparing histochemical and biochemical results, it can be concluded that increased enzymatic activity in tears parallels the severity of corneal damage. Further studies are necessary to evaluate whether the detection of acid beta-galactosidase activity in tears might be useful for diagnostic purposes in humans.

On development of medical informatics education via European cooperation

In this paper, we show different activities of the European Center for Medical Informatics, Statistics and Epidemiology (EuroMISE Center) of Charles University and Academy of Sciences in the field of medical informatics, statistics and epidemiology education and training. The development of these activities started within the TEMPUS-PHARE project in 1993 and they are continuing with the support of another project, particularly the IT EDUCTRA (Information Technologies Education and Training) (Fourth Framework Programme) project. New approaches using the Internet as well as newly developed programmes are described.

Medical informatics education: basic assumption for successful implementation of information technology in the health care sector

In the paper we mention the trends in medical informatics education and we present the development of medical informatics education in the Czech Republic. The actual situation at Czech faculties giving pregraduate courses covering medical informatics topics is described. The enhanced development of medical informatics education via European cooperation is shown. Finally, new approaches to medical informatics education using Internet and special educational software are mentioned.

Education and training in medical informatics, statistics and epidemiology in EuroMISE

The paper gives information on education and training covered by the Joint European Project (JEP) entitled 'Education in the Methodology Field of Health Care, EuroMISE (European Education in Medical Informatics, Statistics and Epidemiology)', that has been running for 3 years (1993-1995) under the umbrella of the European TEMPUS-PHARE programme. Training and education in EuroMISE consists of three overlapping methodological branches: Medical informatics (MI), medical statistics (MS) and epidemiology (E). The teaching scheme has been developed in cooperation between 11 universities in the European Union and Charles University in Prague (four medical faculties, the Faculty of Mathematics and Physics and the Faculty Hospital) together with the Academy of Sciences of the Czech Republic (Institute of Computer Science). The paper shows EuroMISE targets, structure of EuroMISE courses and conferences and gives further views to the future in this field of education.

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.

Computer supported decision making in therapy of arterial hypertension

Therapy of hypertension is still more or less empirical. Several classes of antihypertensive medications are known, the effect of which is based on different mechanisms. The efficacy of the treatment is not always a reliable indication of the appropriate selection as a good therapeutical response can sometimes be achieved at the expense of humoral simulation. This can lead to harmful increased synthesis of trophic hormones. The program for PC called HYPERTENZE supports decision making in therapy of arterial hypertension. It gives a sequence of decisions based on clinical experience using a series of parameters. The program is using the Microsoft Access language of the Access database system and due to the Access Developers Toolkit it does not require Access to be installed on the user's computer. The program HYPERTENZE offers the user essential information and explanation of the decisions in a graded form. The price list of equivalent medications can be updated by the user himself. It seems that this program might be very useful for Czech general practitioners.

Analysis of data about epileptic patients using the GUHA method

In this paper we search for hypotheses on association between the memory quotient and 13 clinical variables examined in a sample of 214 epilepsy patients. We introduce the General Unary Hypotheses Automaton (GUHA) method that automatically generates hypotheses from empirical data by means of computer procedures. Procedure ASSOC of the program GUHA generates and evaluates the hypotheses on symmetrical association or asymmetrical association using quantifiers. The most used symmetrical and asymmetrical quantifiers of the ASSOC procedure are introduced. Data analysis on epileptic patients using the GUHA method is done and the results are presented. We propose a new interpretation of the results including a graphical presentation.

Epidemiology tools program and selected medical applications

In epidemiological research the calculation of appropriate measures of disease frequency is the basis for a comparison of populations and, therefore, the identification of disease determinants. Two frequencies being compared can be combined into a single summary parameter that estimates the association between an exposure and a disease. This can be accomplished by calculating either the ratio of the measures of disease frequency for two populations which indicates how much more likely one population is to develop a disease than another, or the difference between the frequencies which indicates how much greater the frequency of a disease is in one population compared with the other. In epidemiology we often need to compute measures of disease frequency mentioned above. We can do that by means of complex statistical software, but sometimes it is not easy or possible to use this software for an analysis of epidemiological data. At the EuroMISE Center of Charles University and Academy of Sciences in the framework of the research supported from grant COPERNICUS JRP-10053 the E. T. program (Epidemiology Tools) was developed. This program can be used for practical analysis of data from retrospective (case-control) studies or prospective (cohort) studies and for standardization. However, the program can be also a useful teaching tool in the epidemiology courses.

[Medical informatics--decision support systems]

The paper describes medical informatics discipline and deals with decision support systems in more details. It describes the process of decision making using diagnostic and therapeutic decision making cycle and two sources of medical knowledge-scientific and empirical knowledge. It shows different approaches for development of computer supported decision systems and presents some examples of their use in medical practice.

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.

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.

[Is homeopathic therapy more effective that placebos?]

A critical report is presented on the reliability of two clinical trials by Reilly et al. (Lancet, 1986ii, pp. 881-886 and 1994ii, pp. 1601-1606) who has claimed that the effect of homeopathy differs significantly from placebo. Biophysical hypothesis dealing with the intriguing problem of the mechanism of action of homeopathic remedies are also reviewed in this paper.

[Correlation of neuropsychological tests and density of brain white matter in schizophrenia]

In a group of 10 subjects, nine schizophrenic patients and one healthy twin (seven men and three women, i.e. two monozygotic twin pairs: two patients and a healthy man and his sick twin brother, one dizygotic pair of two female patients, three male patients and one female patient without their appropriate twin siblings) Halstead-Reitan Neuropsychological Battery (HRNB) was used and partial neuropsychological tests (Wechsler Memory Scale, the Stroop Color-Word Test, Tonal Memory). The parameters of white matter density were evaluated by computed tomography. The fundamental findings include: In our small group numerous statistically significant correlations were found between neuropsychological tests and white matter density. 2. Higher density is associated with poorer neuropsychological efficiency. There are very similar correlations between neuropsychological variables and density parameters in different areas of the brain. 4. The majority of correlations of neuropsychological parameters is from the area of tactile and motor functions. 5. It is striking that there are statistically significant correlations of density with the simultaneous performance of both hands and the performance of the non-dominant hand but not with the performance of the dominant hand alone. 6. Some correlations pertain in addition to density also to the very controversial problem of the brain size of schizophrenic patients. In the investigated group an association between better neuropsychological performance and larger size of the brain was found. All findings will have to be tested in larger groups of patients and healthy subjects.

Phenytoin as a risk factor in gingival hyperplasia

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.

Medical Informatics, Statistics and Epidemiology Education: In the Framework of the Tempus-Phare Joint European Project

Medicine and health care should react to the changing composition of the population, to diseases and new treatments, to the needs of medical ethics and law, and to changing economic conditions and to social needs. The main goal of health care is to improve the health status of the population. To reach this goal the appropriate use of available information, including for example biomedical knowledge, epidemiological data or patient data, is necessary. The need for education in this field of medical informatics, statistics, and epidemiology is a requirement to solve health-care problems, to develop a long-term perspective and successful functioning of health-care systems. The information sciences can play an important role in promoting the construction of basic data, vocabularies and decision procedures, as well as developing formal methods for problem solving.