Genetic variation as a test of natural selection.
(33/2515)
Allozymic variation encoded by 26 loci was analyzed electrophoretically in 507 specimens representing 12 populations of green toads, Bufo viridis, in Israel and the Vis Adriatic Island. Genetic variation in Bufo viridis is higher than in any vertebrate yet studied. Mean heterozygosity per locus per individual (H) is 0.133 (range, 0.105 to 0.159). H is higher in central populations as compared with isolates, and varies among four major protein classes, being highest in transferases and hydrolases and lowest in oxidoreductases and nonenzymatic proteins. Differential gene frequencies among polymorphisms was tested as an indicator of natural selection. Significant heterogeneity between loci in their apparent inbreeding coefficients Fe=S-2p/P(1-p) was found for all alleles and for each of the four major classes of proteins tested, which may be taken as evidence of selection. Both uniform and diversifying selection are suggested by the low and high Fe values, respectively. The general pattern of high heterozygosity in Bufo viridis is best explained as an adaptive strategy in heterogeneous environments. (+info)
Fats and atheroma: an inquest.
(34/2515)
All well-controlled trials of cholesterol-reducing diets and drugs have failed to reduce coronary (CHD) mortality and morbidity. Nevertheless, commercial, professional, and even government-sponsored propaganda continues. Experimentally some vegetable oils and hardened fats can be more damaging to arteries than butter. There are other hazards to heart muscle from vegetable oils. Israelis consume a high polyunsaturated fat diet equal to that recommended for prevention of CHD in USA but their CHD incidence is very high. Urban Bedouins are also affected. The primary clofibrate prevention trial underlines unacceptable risks which could apply also to diets. Official medical endorsement of these cholesterol reducing measures should be withdrawn. (+info)
Genetic linkage of autosomal-dominant Alport syndrome with leukocyte inclusions and macrothrombocytopenia (Fechtner syndrome) to chromosome 22q11-13.
(35/2515)
Fechtner syndrome is an autosomal-dominant variant of Alport syndrome, manifested by nephritis, sensorineural hearing loss, cataract formation, macrothrombocytopenia, and polymorphonuclear inclusion bodies. As opposed to autosomal-recessive and X-linked Alport syndromes, which have been genetically well studied, the genetic basis of Fechtner syndrome remains elusive. We have mapped the disease-causing gene to the long arm of chromosome 22 in an extended Israeli family with Fechtner syndrome plus impaired liver functions and hypercholesterolemia in some individuals. Six markers from chromosome 22q yielded a LOD score >3.00. A maximum two-point LOD score of 7.02 was obtained with the marker D22S283 at a recombination fraction of 0. Recombination analysis placed the disease-causing gene in a 5.5-Mb interval between the markers D22S284 and D22S1167. No collagen genes or genes comprising the basement membrane have been mapped to this region. (+info)
Primaquine as prophylaxis for malaria for nonimmune travelers: A comparison with mefloquine and doxycycline.
(36/2515)
Malaria prophylaxis for travelers is a controversial issue. The commonly used regimens are associated with side effects, low compliance, or low efficacy, which have raised concern regarding their use. In addition, they are inefficient against the tissue stage of the parasite and thus do not prevent relapses of Plasmodium vivax infection. Primaquine is aimed at the pre-erythrocytic stage and thus may be a potential causal-prophylactic treatment that can abolish the need for long postexposure therapy. During 1995-1998, we followed retrospectively travelers who joined rafting trips to an area in Ethiopia where both P. vivax and Plasmodium falciparum are hyperendemic. Of the 106 travelers who received primaquine, 5.7% developed malaria; of the 19 doxycycline recipients, 53% developed malaria; and of the 25 mefloquine recipients, 52% developed P. vivax malaria (>/=3 months after return from the area of endemicity). Primaquine was well tolerated, and only 1 withdrawal from therapy (due to gastrointestinal symptoms) was reported. Primaquine was shown to be a safe and effective prophylactic drug against both P. falciparum malaria and P. vivax malaria in travelers. (+info)
Mortality differentials among Israeli men.
(37/2515)
OBJECTIVES: This study examined differentials in mortality among adult Israeli men with respect to ethnic origin, marital status, and several measures of social status. METHODS: Data were based on a linkage of records from a 20% sample of the 1983 census to records of deaths occurring before the end of 1992. The study population included 72,527 men, and the number of deaths was 17,378. RESULTS: Differentials is mortality by origin show that mortality was higher among individuals of North African origin than among those of Asian and European origin. After allowance for several socioeconomic indicators, the excess mortality among North African Jews was eliminated. Substantial and consistent differences in mortality were found according to education, occupation, income, possession of a car, housing, and household amenities. Differentials among the elderly were markedly narrower than those among men younger than 70 years. CONCLUSIONS: Some sectors of Israeli society have higher risks of death than others, including, among the male population, these who are poor, less educated, unmarried, unskilled, out of the labor force, and of North African origin. (+info)
Illness and treatment perceptions of Ethiopian immigrants and their doctors in Israel.
(38/2515)
OBJECTIVES: Patient-provider misunderstandings arising from disparate medical and cultural concepts can impede health care among immigrant populations. This study assessed the extent of disagreement and identified the salient problems of communication between Israeli doctors and Ethiopian immigrant patients. METHODS: Semistructured interviews were conducted with 59 Ethiopian immigrants. Self-reports of health status and effectiveness of treatment were compared with evaluations by the primary care physician and supplemented by qualitative data from descriptions of illness, observations of medical visits, informant interviews, and participant observations conducted by the anthropologist. RESULTS: Health status and effectiveness of treatment were rated significantly higher by the doctor than by the patients. Low doctor-patient agreement occurred mainly for illnesses with stress-related or culture-specific associations. Qualitative data suggested that more long-term immigrants may alter their expectations of treatment but continue to experience symptoms that are culturally, but not biomedically, meaningful. CONCLUSIONS: Misunderstandings between immigrant patients and their doctors emerge from the biomedical system's limitations in addressing stress-related illnesses and from culture-based discrepancies in concepts of illness and healing. Including trained translators in medical teams can reduce medical misunderstandings and increase patient satisfaction among immigrant populations. (+info)
Mortality from infectious diseases in Israel, 1979-1992, based on revised ICD-9 codes: implications for international comparisons.
(39/2515)
OBJECTIVES: This study examined trends in infectious disease mortality rates in Israel between 1979 and 1992, using a traditional and a revised set of International Classification of Diseases, Ninth Revision (ICD-9) codes. METHODS: A revised scheme of ICD-9 codes was used to compute mortality rates from infectious diseases for the period 1979 through 1992 by sex and for different age categories. RESULTS: Age-adjusted infectious disease mortality rates based on the revised ICD-9 codes were 3 times higher than those based on traditional codes. Between 1979 and 1992, age-adjusted mortality rates declined more under the revised method than under the traditional method (20% vs 1.7%). CONCLUSIONS: The revised set of ICD-9 codes allows a more comprehensive view of the burden of infectious diseases on public health. (+info)
Aggression patterns and speciation.
(40/2515)
The evolutionary significance of interspecific aggression as a factor in speciation was tested among three chromosome forms of the actively speciating fossorial rodent Spalax ehrenbergi in Israel. Laboratory experiments testing intra- and interspecific aggression were conducted on 48 adult animals from 10 populations comprising three chromosome forms with 2n = 52, 58, and 60. Twelve agonistic, motivational-conflict, and territorial behavioral variables were recorded during 72 combats involving homo- and heter-ogametic encounters between opponents. Analysis of the data matrix was carried out by the nonmetric multivariate Smallest Space Analysis (SSA-II). The results indicate that (a) aggression patterns, involving agonistic conflict and territorial variables, are higher in heterogametic encounters than in homogametic ones; and (b) aggression is higher between contiguous chromosome forms (2n = 58-60, and 2n = 52-58) than between noncontiguous ones (2n = 52-60). Both a and b suggest that high interspecific aggression appears to be adaptively selected at final stages of speciation in mole rats as a premating isolating mechanism which reinforces species identification and establishes parapatric distributions between the evolving species. (+info)