Caracterización de poblaciones de phytophthora infestans (mont, de bary) obtenidas de solanum transgénicas y de híbridos somáticos resistentes

En el valle de Toluca, México, durante el verano de 2003, clones obtenidos por ingeniería genética y por hibridación somática entre Solanum tuberosum y S. bulbocastanum fueron expuestos a infección natural por Phytophthora infestans, a fin de cuantificar su resistencia al oomiceto, previamente comprobada en otras condiciones. El objetivo fue identificar los genotipos de P. infestans que selectiva y progresivamente infectaron a los clones de papa. La mayoría de éstos fueron resistentes en los estados tempranos de crecimiento, aunque se presentó infección gradual posteriormente. Se identificaron 21 variantes de P. infestans con base al tipo de compatibilidad (TC) y a los perfiles multilocus aloenzimáticos de glucosa-6-fosfato isomerasa (Gpi) y peptidasa (Pep ). A la sexta semana postsiembra se obtuvieron las primeras infecciones por cinco aislamientos en el testigo no transformado (H6, cv. Katahdin). A la siguiente semana, en el mismo hospedante, se aislaron otros cinco genotipos de P. infestans, cuatro de ellos diferentes a los de la semana anterior, y se presentaron otros cuatro genotipos en un clon que no adquirió la transgenia (H4). Ambos clones murieron a la mitad del ciclo de cultivo. Los genotipos más frecuentes infectando todos los clones, principalmente al final del ciclo, fueron A1, 100/100, 100/100 (TC, Gpi, Pep , 19%), y A2, 100/100, 100/100 (14%). La proporción A1:A2 para toda la población fue 1:1 (86,77; 52,7%:47,3%). Se concluye que hubo gran diversidad genética de P. infestans, que los transgenes que confieren la resistencia funcionaron bien en plantas jóvenes, al principio del ciclo de cultivo, y no se observó especificidad hospedero-patógeno

Metoprolol for the Prevention of Acute Exacerbations of COPD.

BACKGROUND: Observational studies suggest that beta-blockers may reduce the risk of exacerbations and death in patients with moderate or severe chronic obstructive pulmonary disease (COPD), but these findings have not been confirmed in randomized trials. METHODS: In this prospective, randomized trial, we assigned patients between the ages of 40 and 85 years who had COPD to receive either a beta-blocker (extended-release metoprolol) or placebo. All the patients had a clinical history of COPD, along with moderate airflow limitation and an increased risk of exacerbations, as evidenced by a history of exacerbations during the previous year or the prescribed use of supplemental oxygen. We excluded patients who were already taking a beta-blocker or who had an established indication for the use of such drugs. The primary end point was the time until the first exacerbation of COPD during the treatment period, which ranged from 336 to 350 days, depending on the adjusted dose of metoprolol. RESULTS: A total of 532 patients underwent randomization. The mean (±SD) age of the patients was 65.0±7.8 years; the mean forced expiratory volume in 1 second (FEV CONCLUSIONS: Among patients with moderate or severe COPD who did not have an established indication for beta-blocker use, the time until the first COPD exacerbation was similar in the metoprolol group and the placebo group. Hospitalization for exacerbation was more common among the patients treated with metoprolol. (Funded by the Department of Defense; BLOCK COPD ClinicalTrials.gov number, NCT02587351.)

Cytokine gene variation is associated with depressive symptom trajectories in oncology patients and family caregivers

PURPOSE: Depressive symptoms are common in cancer patients and their family caregivers (FCs). While these symptoms are characterized by substantial interindividual variability, the factors that predict this variability remain largely unknown. This study sought to confirm latent classes of oncology patients and FCs with distinct depressive symptom trajectories and to examine differences in phenotypic and genotypic characteristics among these classes. METHOD: Among 167 oncology outpatients with breast, prostate, lung, or brain cancer and 85 of their FCs, growth mixture modeling (GMM) was used to identify latent classes of individuals based on Center for Epidemiological Studies-Depression (CES-D) scores obtained prior to, during, and for four months following completion of radiation therapy. One hundred four single nucleotide polymorphisms (SNPs) and haplotypes in 15 candidate cytokine genes were interrogated for differences between the two largest latent classes. Multivariate logistic regression analyses assessed effects of phenotypic and genotypic characteristics on class membership. RESULTS: Four latent classes were confirmed: Resilient (56.3%), Subsyndromal (32.5%), Delayed (5.2%), and Peak (6.0%). Participants who were younger, female, non-white, and who reported higher baseline trait and state anxiety were more likely to be in the Subsyndromal, Delayed, or Peak groups. Variation in three cytokine genes (i.e., interleukin 1 receptor 2 [IL1R2], IL10, tumor necrosis factor alpha [TNFA]), age,and performance status predicted membership in the Resilient versus Subsyndromal classes. CONCLUSIONS: Findings confirm the four latent classes of depressive symptom trajectories previously identified in a sample of breast cancer patients. Variations in cytokine genes may influence variability in depressive symptom trajectories