Israel Medical Association Journal

The complex genetic nature of many common diseases makes the identification of the genes that predispose to these ailments a difficult task. In this review we discuss the elements that contribute to the complexity of polygenic diseases and describe an experimental strategy for disease-related gene discovery that attempts to overcome these factors. This strategy involves a population-based case-control paradigm and makes use of a highly informative, homogeneous founder population, many of whose members presently reside in Israel. The properties of single nucleotide polymorphisms, which are presently the markers of choice, are discussed, and the technologies that are currently available for SNP[1] genotyping are briefly presented.

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[1] SNP = single nucleotide polymorphism

Intractable forms of autoimmune diseases follow a rapid course, with a significantly shortened life expectancy sometimes comparable to that of malignant diseases. Immunoablative therapy, including high dose cytotoxic agents and hematopoietic autologous stem cell rescue, was recently introduced as an aggressive approach to treat autoimmune diseases that have a rapid course and are resistant to conventional therapy. The most frequent indication for this type of treatment is multiple sclerosis, seconded by systemic sclerosis. The results of immunoablative treatment with documented responses in both diseases are encouraging. The data are mature enough to begin comparative randomized studies of immunoablative versus conventional treatment to validate the benefit of the aggressive approach. A randomized trial involving SSc[1] was recently launched (ASTIS) and a trial involving MS[2] is under preparation. Considerably less experience with immunoablative treatment has been gained in systemic lupus erythematosus, rheumatoid arthritis, and other disorders with an autoimmune pathophysiology. Autologous hematopoietic stem cell transplantation in humans offers more long-lasting immunosuppression than reeducation of lymphocytes. In fact, allogeneic transplantation may replace the whole immune system. However, this attractive approach is still associated with considerable morbidity and mortality and is not yet justified for treatment of automimmune diseases. Non-myeloablative allogeneic transplantation and sub-myeloblative high dose cyclophosphamide without stem cell support are alternative approaches that could be explored in pilot studies.

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Background: The importance of health promotion and disease prevention in health policy and clinical practice is widely accepted in many countries. However, a large number of medical schools do not dedicate a significant part of their curriculum to these aspects. In Israel, there are no reports on the training of the future physician towards his or her role as health promoter in general, or in the areas of cardiovascular and cancer diseases specifically.

Objectives: To examine the preparation of Israel medical students for the role of health promoter in cancer and cardiovascular diseases.

Methods: The study was carried out over 2 years in two of the four medical schools in Israel: the Sackler Faculty of Medicine at Tel Aviv University and the Faculty of Health Sciences at Ben Gurion University in Beer Sheva. The students (n=172, 70% response rate) were surveyed during 1999-2000 by means of a questionnaire, which included assessment of their training towards the role of health promoter, their clinical experiences and exposure to patients at different stages of illnesses at various medical sites, and the specific skills and relevant knowledge they acquired.

Results: Most of the students’ learning experiences occurred in hospitals with patients at the treatment stage and little time was dedicated to prevention, especially in the community. They demonstrated better knowledge, skills and satisfaction with their learning experiences in CVD than in cancer; and reported having insufficient exposure to several common cancer diseases and lacking examining skills for early detection of cancer. The students in Beer Sheva had significantly more interaction with patients at different stages of CVD and acquired more examination skills than the Tel Aviv students.

Conclusions: A change in the curriculum is urgently needed: namely training medical students in community settings and preparing them to promote the well-being of their patients, including prevention. Attention should be given to launching new learning modes in the pre-clinical and clinical curriculum. We propose that: a) pre-clinical courses include prevention techniques in CVD and cancer, problems of cancer patients, and some examining skills; and b) the clinical phase should integrate oncology concepts and total cancer and CVD care into existing clerkships in the hospitals and in the community.
 

Background: The large number of cases of West Nile fever diagnosed in Israel in 2000 once again brought into focus the confusion that frequently accompanies the use of the term “epidemic”.

Objective: To examine the different definitions of the term “epidemic” and to propose ways in which it can be used to both improve communication among professionals and provide the public with a better sense of the associated risks.

Methods: The literature wes reviewed for the various definitions of the terms “epidemic” and “outbreak”. Sources included popular and medical dictionaries, ancient documents, epidemiology texts, legal texts, and the medical literature.

Result: The term epidemic is variously defined. The broad definition given by epidemiologists - namely, more disease the is anticipated by previous experience - is less meaningful to the general public. In some ways it conflicts with the definitions found in the popular literature, which generally imply danger to the public and a very large number of victims.

Conclusions: The interpretation of the term epidemic may vary according to the context in which it is used. For risk communication, we suggest that every effort be made to add descriptive terms that characterize the epidemic.

Background: Knowledge of the prevalence of chronic disease in the population is essential for health planners and providers.

Objectives:To present the results of a concentrated effort by the largest health maintenance organization in Israel (Clalit Health Services) in order to develop a comprehensive register of chronic diseases.

Methods: In 1998, all 2,704 primary care physicians in Israel’s largest health provider were requested to report on all patients with selected chronic diseases. In addition, all the filled prescriptions for medications relevant to the investigated diseases and all relevant hospitalization events were added to the database. Prevalence rates were calculated based on the reporting practices only (1,653 physicians responsible for a total of 1,409,725 adults).

Results: Hypertension (10.2/100), diabetes (6.1/100), hyperlipidemia (5.7/100), peptic ulcer (4.7/100) and ischemic heart disease (4.3/100) were the most prevalent. Females had significantly higher rates of hypothyroidism, psychoses, neu­roses and malignancies, and lower rates of ischemic heart disease, chronic obstructive pulmonary disease, heart failure and asthma. Arabs had higher rates of diabetes mellitus and lower rates of ischemic heart disease, hypertension and hyperlipidemia than Jews. About 20% of the adult population had one or more of the selected chronic diseases.

Conclusions: Differences in rates noted between physi­cians, not explainable by population characteristics, may reflect differences in the quality and delivery of health services. Rate differences between demographic subgroups call for further studies on the etiology, susceptibility and natural history of these diseases.
 

The hepatitis C virus is an enveloped positive-sense single-stranded RNA virus, which has been classified into 6 major genotypes and over 100 subtypes. HCV replicates mainly in the hepatocyte. Recently, infectious HCV cDNA clones have been generated. Despite evidence that innate and adaptative humoral and cellular immune responses are activated as part of an antiviral defense, HCV has a remarkable ability to establish persistent infection. The analysis of viral kinetics using mathematical modeling shows a relative steady state without treatment, while an immediate biphasic HCV decline occurs in blood during successful treatment, the latter being predictive of clearance of HCV by the end of treatment.