A genome scanning approach to assess the genetic effects of radiation in mice and humans.

We used Restriction Landmark Genome Scanning (RLGS) to assess, on a genome-wide basis, the mutation induction rate in mouse germ cells after radiation exposure. Analyses of 1,115 autosomal NotI DNA fragments per mouse for reduced spot intensity, indicative of loss of one copy, in 506 progeny derived from X-irradiated spermatogonia (190, 237 and 79 mice in 0-, 3-, and 5-Gy groups, respectively), permitted us to identify 16 mutations affecting 23 fragments in 20 mice. The 16 mutations were composed of eight small changes (1-9 bp) at microsatellite sequences, five large deletions (more than 25 kb), and three insertions of SINE B2 or LINE1 transposable elements. The maximum induction rate of deletion mutations was estimated as (0.17 +/- 0.09) x 10(-5)/locus Gy(-1). The estimate is considerably lower than 1 x 10(-5)/locus Gy(-1), the mean induction rate of deletion mutations at Russell's 7 loci, which assumed that deletion mutations comprise 50% of all mutations. We interpret the results as indicating that the mean induction rate of mutations in the whole genome may be substantially lower than that at the 7 loci. We also demonstrate the applicability of RLGS for detection of human mutations, which allows direct comparisons between the two species.

Evolutionary health promotion.

Health promotion's promise is enormous, but its potential is, as yet, unmatched by accomplishment. Life expectancy increases track more closely with economic prosperity and sanitary engineering than with strictly medical advances. Notable achievements in the past century--the decreased incidences of epidemic infections, dental caries, and stomach cancer--are owed to virologists, dentists, and (probably) refrigeration more than to physicians. Prevention speaks against tobacco abuse with a single voice, but in many other areas contradictory research findings have generated skepticism and even indifference among the general public for whom recommendations are targeted. Health promotion's shortcomings may reflect lack of an overall conceptual framework, a deficiency that might be corrected by adopting evolutionary premises: (1) The human genome was selected in past environments far different from those of the present. (2) Cultural evolution now proceeds too rapidly for genetic accommodation--resulting in dissociation between our genes and our lives. (3) This mismatch between biology and lifestyle fosters development of degenerative diseases. These principles could inform a research agenda and, ultimately, public policy: (1) Better characterize differences between ancient and modern life patterns. (2) Identify which of these affect the development of disease. (3) Integrate epidemiological, mechanistic, and genetic data with evolutionary principles to create an overarching formulation upon which to base persuasive, consistent, and effective recommendations.

The newly characterized colicin Y provides evidence of positive selection in pore-former colicin diversification.

Two evolutionary mechanisms have been proposed in the process of protein diversification of the large family of antimicrobial toxins of Escherichia coli, known as the colicins. Data from previous studies suggest that the relatively rare nuclease colicins appear to diversify primarily through the action of positive selection, whilst the more abundant pore-former colicins appear to diversify through the action of recombination. The complete DNA sequence of the newly characterized colicin plasmid, pCol-Let, isolated from a Yanomama Indian of South America, is presented here. This plasmid encodes a newly identified pore-former colicin, colicin Y. DNA and protein sequence comparisons of the colicin Y gene cluster and the encoded proteins with those of published pore-former colicins provide the first evidence that positive selection may also act to increase pore-former colicin diversity.

Blood polymorphisms and morphological variability in Brazilian Indians.

A total of 1,025 adults belonging to four Brazilian tribes were simulataneously studied for 12-16 anthropometric characteristics and 7-11 blood polymorphic loci. Several comparisons using both univariate and multivariate statistical techniques failed to show the negative correlation between these two sets of variables found by other workers. © 1994 Wiley-Liss, Inc.

Estudos epidemiologicos entre populaçoes Amerindias da Amazonia. III. Parasitoses intestinais em povoaçoes recentemente contactadas e em aculturaçao / Epidemiologic studies among Amerindian populations of Amazonia. III.Intestinal parasitosis in populations recently contacted and in process of acculturation

Os predominios de parasitas intestinais entre os residentes de tres povoaçoes de indios sul-americanos no processo de aculturaçao foram comparados com os encontrados em pesquisas anteriores, nao publicadas, em duas povoaçoes recentemente contactadas. Embora um individuo, em uma povoaçao, em aculturaçao, hospedasse 11 diferentes parasitas intestinais, em geral, o numero medio de diferentes especies de parasitas por pessoa era tanto maior nas povoaçoes recentemente contactadas. A contagem de ovos de helmintos, efetuada diretamente nas sujeiras de cada especime de uma vila recentemente contactada, foi baixa. Nao houve diferenças em predominio associadas ao sexo. Os predominios totais, nao ajustados por idade, estavam entre os mais altos reegistrados para amerindios. Nenhuma especie de Taenia ocorreu. Balastidium coli ocorreu em duas vilas em aculturaçao, concomitante com o inicio de praticas agricolas que incluem criaçao de suinos. Nenhum caso de ma nutriçao de caloria protica moderada ou severa foi observado em qualquer das vilas durante as pesquisas. Estes limitados dados fornecem uma linha base para futuras comparaçoes, e, talvez, um olhar rapido no passado

Control of disease in Amerindians in cultural transition

Meeting of the Advisory Committe on Medical Research, 13. Pan American Health Organization; 24-28 Jun. 1974

The American Indian in the international biological program

Meeting of the Advisory Committee on Medical Research, 7. Pan American Health Organization; 24-28 Jun. 1968

Control de las enfermedades de los ameridios en transición cultural / Control of diseases among ameridians in cultural transition

Es difícil pronosticar los efectos de cualquier medida externa sobre grupos ameridios con quienes se establecerá un nuevo contacto. Por esta razón ocurre que algunas medidas clásicas, entre ellas las de salud, destinadas a beneficiar a estos grupos, producen efectos secundarios perjudiciales. En este artículo se examinan estos efectos y se sugieren varios procedimientos para evitarlos o dominarlos