Significant linkage to airway responsiveness on chromosome 12q24 in families of children with asthma in Costa Rica.

Although asthma is a major public health problem in certain Hispanic subgroups in the United States and Latin America, only one genome scan for asthma has included Hispanic individuals. Because of small sample size, that study had limited statistical power to detect linkage to asthma and its intermediate phenotypes in Hispanic participants. To identify genomic regions that contain susceptibility genes for asthma and airway responsiveness in an isolated Hispanic population living in the Central Valley of Costa Rica, we conducted a genome-wide linkage analysis of asthma (n = 638) and airway responsiveness (n = 488) in members of eight large pedigrees of Costa Rican children with asthma. Nonparametric multipoint linkage analysis of asthma was conducted by the NPL-PAIR allele-sharing statistic, and variance component models were used for the multipoint linkage analysis of airway responsiveness as a quantitative phenotype. All linkage analyses were repeated after exclusion of the phenotypic data of former and current smokers. Chromosome 12q showed some evidence of linkage to asthma, particularly in nonsmokers (P < 0.01). Among nonsmokers, there was suggestive evidence of linkage to airway responsiveness on chromosome 12q24.31 (LOD = 2.33 at 146 cM). After genotyping 18 additional short-tandem repeat markers on chromosome 12q, there was significant evidence of linkage to airway responsiveness on chromosome 12q24.31 (LOD = 3.79 at 144 cM), with a relatively narrow 1.5-LOD unit support interval for the observed linkage peak (142-147 cM). Our results suggest that chromosome 12q24.31 contains a locus (or loci) that influence a critical intermediate phenotype of asthma (airway responsiveness) in Costa Ricans.

Alergia a los animales de laboratorio en bioterios de la Universidad Central de Venezuela: factores de riesgo / Allergy to laboratory animals at the Central University of Venezuela: risk factors

Los trabajadores de laboratorios de animales tienen un alto riesgo de desarrollar alergias ocupacionales. En muchos casos, la severidad de los síntomas impide seguir trabajando con los animales. Realizamos este estudio para estimar la frecuencia de síntomas de alergia en un grupo de ocho trabajadores de laboratorios de animales procedentes de dos bioterios de la Universidad Central de Venezuela, a fin de determinar su asociación con varios factores del huésped. Todos los participantes completaron un cuestionario y se les realizaron pruebas de hipersensibilidad inmediata a alergenos comunes, pruebas de provocación con metacolina y determinación de IgE sérica total. Los síntomas de alergia se presentaron en 50 por ciento de los pacientes y estaban relacionados con el tiempo de exposición laboral, pruebas de piel positivas e IgE sérica elevada. Por tanto, una historia personal de atopía, pruebas de piel a alergenos comunes positiva, y un valor IgE sérica elevado parecieran ser factores de riesgo importantes para el desarrollo de alergia a a los animales de laboratorio

Time course of the recovery from bronchoconstriction induced by inhaled methacholin in asthmatic and normal subjects

OBJETIVOS: Determinar o tempo de recuperaçäo e os mecanismos envolvidos na recuperaçäo da constriçäo brônquica induzida pela metacolina inalada em indivíduos asmáticos e hígidos. PACIENTES E MÉTODOS: No primeiro estudo, seis asmáticos e três näo-asmáticos, todos näo fumantes, foram estudados em três dias separados. Em cada dia os indivíduos inalaram doses de metacolina que iam sendo duplicadas (com uma concentraçäo máxima de até 256mg/ml) até que houvesse uma queda de 2o por cento no seu volume expiratório forçado no primeiro segundo...

Role of cholinergic nervous system in healing neuropathic lesions: preliminary studies and prospective, double-blinded, placebo-controlled studies.

The amplitudes of photo-electric-plethysmography (PPG) tracings were significantly increased by subcutaneous injections of methacholine (MC) and diminished by injections of atropine (AT) as compared with placebo injections of multi-electrolyte solution (MES) both in 8 normal subjects and 11 patients with diabetic peripheral neuropathy. AT-containing lotion delayed healing compared with placebo in the forearms of 6 normal subjects. MC-containing lotion sped healing compared with placebo in the forearms of 6 subjects with diabetic neuropathy. Thigh incisions in 6 neuropathic patients were shown to heal faster if soaked in MES rather than saline. Healing with the MES solution was shown to be further increased by the addition of MC to the solution and to be decreased by the addition of AT. The addition of MC produced erythema and an increase in the amplitude of PPG tracings. AT solutions produced blanching and a decrease in the PPG amplitude. It was concluded that (1) the slow healing characteristic of neuropathic ulcers is associated with a loss of cholinergic nerve function; (2) cholinergic stimulation will increase capillary blood flow and promote healing while cholinergic blockade has opposite effects; (3) secondary ischemia makes the ulcers susceptible to the deleterious effects of therapeutic agents such as saline; (4) the ischemic tissue will heal faster with a balanced MES than with saline; and (5) the benefits of MES on healing are augmented in patients with diabetic neuropathy by the addition of cholinergic agents to the solution.