Drogadição e contexto familiar na história de indivíduos HIV positivo : um estudo fenomenológico

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Drogadição e contexto familiar na história de indivíduos HIV positivo : um estudo fenomenológico

88

Drogadição e contexto familiar na história de indivíduos HIV positivo : um estudo fenomenológico

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CYP1A1 *2B and *4 polymorphisms are associated with lung cancer susceptibility in Mexican patients

Background: CYP1A1 is a gene involved in the high aryl hydrocarbon hydroxylase -inducible phenotype, which is a genetically-determined variation among individuals that has been associated with lung cancer risk. More specifically, CYP1A1*2B and *4 polymorphisms have been associated with high susceptibility to lung cancer among cigarette smokers. Materials and methods: DNA was obtained from blood samples and we studied by PCR-RFLP the distribution of CYP1A1*2B (n=248) and *4 (n=222) polymorphisms in healthy controls and 222 lung cancer patients from a Mexican population. Results: Comparisons between groups showed an increased risk for lung cancer patients of *2B/*2B (18%; OR 7.6; 95% CI 3.0-19.2) and *4/*4 genotypes (15%; OR 11.45; 95% CI 2.19-59.85) compared to the control group (1% for *2B/*2B and 4.4% for *4/*4). A significant association between lung cancer and homozygous ?2B/*2B passive smokers and *4/*4 ever (cigarettes) and passive smokers was also observed (p<0.05). Multivariate analysis revealed an increased risk for the *2B/2B genotype (OR 6.83), as well as for *4/*4 (OR 28.8). Conclusion: The results of the study indicate a significant association between *2B/*2B and *4/*4 genotypes and the risk of developing lung cancer among Mexicans. � 2008 Wichtig Editore

CYP1A1 *2B and *4 polymorphisms are associated with lung cancer susceptibility in Mexican patients

Background: CYP1A1 is a gene involved in the high aryl hydrocarbon hydroxylase -inducible phenotype, which is a genetically-determined variation among individuals that has been associated with lung cancer risk. More specifically, CYP1A1*2B and *4 polymorphisms have been associated with high susceptibility to lung cancer among cigarette smokers. Materials and methods: DNA was obtained from blood samples and we studied by PCR-RFLP the distribution of CYP1A1*2B (n=248) and *4 (n=222) polymorphisms in healthy controls and 222 lung cancer patients from a Mexican population. Results: Comparisons between groups showed an increased risk for lung cancer patients of *2B/*2B (18%; OR 7.6; 95% CI 3.0-19.2) and *4/*4 genotypes (15%; OR 11.45; 95% CI 2.19-59.85) compared to the control group (1% for *2B/*2B and 4.4% for *4/*4). A significant association between lung cancer and homozygous ≤2B/*2B passive smokers and *4/*4 ever (cigarettes) and passive smokers was also observed (p<0.05). Multivariate analysis revealed an increased risk for the *2B/2B genotype (OR 6.83), as well as for *4/*4 (OR 28.8). Conclusion: The results of the study indicate a significant association between *2B/*2B and *4/*4 genotypes and the risk of developing lung cancer among Mexicans. © 2008 Wichtig Editore

Primed carrot seeds performance under water and temperature stress Desempenho de sementes osmocondicionadas de cenoura sob estresse hídrico e térmico

Uniformity and percentage of seedling emergence of direct-seeded vegetables have a major impact on their yield and quality. Depending on temperature and soil water potential, carrot seeds performance in the field is poor justifying the use of techniques to accelerate the germination and seedling emergence. The objective of this work was to evaluate the effects of priming treatments, with and without aeration, on carrot seeds performance under water and temperature stress. Two seed lots of carrots, Brasília cultivar, were primed in PEG 6000 -1.0 and -1.2 MPa solutions, for four and eight days, at 20ºC, using two imbibition methods: priming in paper towel moistened with the respective solutions and immersion into aerated osmotic solutions. Non-primed seeds were used as control. After priming, the seeds were dried at room temperature until reach initial seed moisture content. The seeds were submitted to the following tests: germination, first count, seedling emergence in the field, germination at sub-optimal (15ºC) and supra-optimal temperature (30ºC) and germination under water stress (PEG 6000 at -0.4 MPa). Priming in -1.0 and -1.2 MPa PEG 6000 during four and eight days can be useful for improving carrot seedling emergence in the field and seed performance under supra and sub-optimal temperatures. Aeration of the peg solution was beneficial when seeds were primed at -1.2 MPa for eight days.<br>Na cultura da cenoura são constantes os problemas relativos ao desempenho das sementes em campo, justificando técnicas que acelerem a germinação das sementes e a emergência das plântulas. O objetivo deste trabalho foi avaliar o efeito do condicionamento osmótico, com e sem uso de soluções aeradas, no desempenho de sementes de cenoura sob estresse hídrico e térmico. Para tanto, sementes de dois lotes, cv. Brasília, foram condicionadas em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, a 20ºC, utilizando-se dois métodos de embebição para o condicionamento: em papel toalha umedecido com as respectivas soluções e imersão em soluções osmóticas aeradas. Sementes não condicionadas foram utilizadas como testemunha. Após o condicionamento, as sementes foram secas em ambiente de laboratório até atingirem o grau de umidade inicial. Em seguida, foram avaliadas pelos seguintes testes: germinação, primeira contagem de germinação, emergência das plântulas em campo, germinação a temperatura sub (15ºC) e supra-ótima (30ºC) e germinação sob estresse hídrico (PEG 6000 a -0,4 MPa). O condicionamento osmótico das sementes de cenoura em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, é recomendado para aumentar a emergência de plântulas em campo e o desempenho sob temperatura sub e supra-ótima. O uso de soluções aeradas de PEG foi benéfico apenas quando as sementes foram condicionadas a -1,2 MPa por oito dias

Germination and vigour of primed asparagus seeds Germinação e vigor de sementes de aspargo osmoticamente condicionadas

The osmotic conditioning or priming is considered a promising technique to speed up germination and to improve seed performance. Four seed lots of asparagus, Mary Washington cultivar, were primed at 25&deg;C for seven or 14 days using PEG 6000 at -1.0 or -1.2 MPa, or sea water at -3.3 MPa; or for three days in distilled water. The physiological quality of the seeds was evaluated by standard germination, first count germination, speed of seedling emergence, and germination percentage and seedling fresh and dry weights after controlled deterioration test. Primed seeds presented higher germination speed, independently of their initial physiological quality. Beneficial effects of priming on germination and vigour were more expressive in the seed lot of low physiological quality. Priming in PEG 6000 at -1.0 MPa for 14 days was the most beneficial treatment to improve asparagus seeds performance.<br>O condicionamento osmótico ou priming tem sido considerado uma técnica promissora para acelerar a germinação e melhorar o desempenho das sementes. Sementes de quatro lotes de aspargo, cv. Mary Washington, foram condicionadas em PEG 6000 a -1,0 e -1,2 MPa, por 7 e 14 dias, em água do mar a -3,3 MPa, por 7 e 14 dias e em água destilada por 3 dias, em BOD a 25&deg;C. Sementes não condicionadas foram usadas como testemunha. A qualidade fisiológica das sementes foi avaliada pela germinação, primeira contagem de germinação, velocidade de emergência e pela porcentagem de geminação e pesos da matéria fresca e seca das plântulas obtidas no teste de deterioração controlada (45&deg;C/24 horas). O experimento foi instalado no delineamento inteiramente casualizado com quatro repetições e oito tratamentos, sendo as médias comparadas pelo teste de Duncan a 5%. Sementes de aspargo condicionadas osmoticamente apresentaram maior velocidade de germinação, independentemente de sua qualidade fisiológica inicial. Efeitos benéficos do condicionamento osmótico, na germinação e no vigor, foram mais expressivos no lote de baixa qualidade fisiológica. O condicionamento em PEG a -1,0 MPa por 14 dias foi, em geral, o tratamento mais adequado para promover melhoria na qualidade fisiológica dessas sementes