Decision trees based on automatic learning and their use in cardiology

Computerized information systems, especially decision support systems, have become an increasingly important role in medical applications, particularly in those where important decision must be made effectively and reliably. But the possibility of using computers in medical decision making is limited by many difficulties, including the complexity of conventional computer languages, methodologies and tools. Thus a conceptual simple decision making model with the possibility of automating learning should be used. In this paper we introduce a cardiological knowledge-based system based on the decision tree approach supporting the mitral valve prolapse determination. Prolapse is defined as the displacement of a bodily part from its normal position. The term mitral valve prolaps (PMV), therefore, implies that the mitral leaflets are displaced relative to some structure, generally taken to be the mitral annulus. The implications of the PMV are the following: disturbed normal laminar blood flow, turbulence of the blood flow, injury of the chordae tendinae, the possibility of thrombus's composition, bacterial endocarditis, and finally hemodynamic changes defined as mitral insufficiency and mitral regurgitation. Uncertainty persists about how it should be diagnosed and about its clinical importance. It is our deep belief that the echocardiography enables properly trained experts armed with proper criteria to evaluate PMV almost 100%. But unfortunately, there are some problems concerned with the use of echocardiography. In that manner we have decided to start a research project aimed at finding new criteria and enabling the general practitioner to evaluate PMV using conventional methods and to select potential patients from the general population. To empower one to perform needed activities we have developed a computer tool called ROSE (computeRised prOlaps Syndrom dEtermination) based on algorithms of automatic learning. This tool supports the definition of new criteria and the selection of potential PMV-patients.     

Synthesis and testing of anticonvulsant properties of 5-benzylidene derivatives of 3-o-, 3-m- I 3-p-chlorophenyl-2-thiohydantoin]

Ten new 3-(o-, 3-(m- and 3-(p-chlorophenyl)-5-benzylidene derivatives of 2-thiohydantoin were obtained. Their IR spectra were recorded. The obtained compounds were tested for anticonvulsant activity using the test of minimal and maximal pentetrazol shock in mice, and the MES test in rats.     

Orbital Hydatid Cyst: CT and MRI

Orbital hydatid cyst is rare. We present a case with CT and MRI, emphasizing the superiority of the latter. Received: 19 August 1996 Accepted: 9 September 1996     

Plasma erythropoietin level and iron reserves in haemodialysis patients with and without acquired cystic kidney disease

Concentration of erythropoietin (Epo) and iron reserves (IR) belong to the essential factors determining erythropoiesis in haemodialysis patients. Patients on dialysis with acquired kidney disease (ACKD+) can control anaemia better than patients without acquired kidney disease (ACKD-). Therefore we decided to check if plasma Epo levels and IR differ significantly in both groups of patients. Forty chronically haemodialyzed patients after ultrasound diagnosis were divided into 18 patients (45%) with ACKD+ and 22 (55%) without ACKD-. In both groups of patients we compared their plasma levels of Epo and IR. Plasma erythropoietin and ferritin levels were measured by enzymatic immunoassay. Iron reserves were estimated by the formula: IR=400×[ln(ferritin)-ln(50)]. In the ACKD+ group 72% of patients and in the ACKD-group 32% of patients did not require rHu Epo therapy. Plasma levels of erythropoietin and iron reserves did not differ significantly between ACKD+ and ACKD—patients. There must be also other factors than erythropoietin levels and iron reserves regulating erythropoiesis in these patients.     

Present status of undergraduate urological education in Turkey: is standardization necessary?

23 medical faculties exist in Turkey at the moment and 2 others are being established. Considering that all these faculties run their own programs independently, different education systems might effect the standard of doctors and health care. All of the new graduates in this country face a centralized examination for postgraduate posts in teaching hospitals or start an obligatory service under the authority of the Ministry of Health and Social Welfare. This necessitates standardization in medical education to provide equal facilities and opportunities to all young doctors. Questionnaires, replied to by the urology departments of medical faculties, reflect a wide range of teaching periods in urology with a broad spectrum of topics. Under these circumstances it is advisory to agree on both the time period and content of a standard urology program, as well as other subjects, for better health care and equal chances in centralized examinations.     

Strecker stent in stenotic hemodialysis Brescia-Cimino arteriovenous fistulas

Flexible tantalum stents (Strecker) were used as an adjunct to percutaneous transluminal angioplasty (PTA) in the treatment of stenotic arterial or venous limbs of Brescia-Cimino hemodialysis fistulas. The diagnostic procedure was performed using retrograde fistulography. After PTA with unsatisfactory results, stents were placed in 5 patients with significant residual stenoses and poor fistula function. Within the mean follow-up period of 6.4 months (range 3–10 months) all fistulas were functioning. We conclude that Strecker stent is useful in the treatment of stenotic hemodialysis arteriovenous fistulas as an adjunct to PTA.