[Risk factors related to allergic diseases at Mexico City].

Background: Several studies suggest that the prevalence of allergic diseases has been increasing worldwide in recent years; then it is very important to identify some risk factors that could be related.

Objective: To know some hereditary and environmental risk factors that could be related to the development of allergic diseases in open population from Mexico City.

Patients And Method: It was an open-population, cross-sectional trial, in two phases with a random sample size of 4272 individuals in 214 public health centers.

X chromosome monosomy in primary and overlapping autoimmune diseases.

Female predominance is a common characteristic for autoimmune diseases attributed to the combined effect of hormonal influence and genetic factors. Since X chromosome has immunologically important genes, the age related X chromosome loss could contribute to the development of autoimmunity. X chromosome monosomy (XCM) has been associated with primary biliary cirrhosis (PBC) and systemic sclerosis.

[Prevalence of allergic diseases in Mexico City].

Background: There is a considerable variation in the prevalence of allergic disorders in developing countries. These differences may be attributable to different methodological problems and to the lack of operational definitions. Several studies suggest that the prevalence of allergic diseases has been increasing worldwide in recent years.

Maintenance of subcutaneous cavities with CO2.

Unlabelled: Since mechanical retractors in endoscopic plastic surgery cause certain drawbacks, we developed a model in dogs, which, by insufflating CO2 into a subcutaneous cavity, we were able to maintain. We evaluated the magnitude of subcutaneous emphysema and absorption of CO2 by insufflating different pressures and the efficacy of external pressure on the skin with the purpose of limiting the subcutaneous emphysema. Sixteen dogs were divided in 3 groups, A, B, and C.

[Variations in a 24-year period of colorectal and gastric cancer in Mexico].

Objective: Gastric cancer (CG) and colorectal cancer (CCR) are the two most common neoplasms of the digestive system in the world. We performed a study to determine incidence and relation between CG and CCR in five hospitals in Mexico City.

Methods: Patients with admitted diagnosis of CG and CCR at Hospital General de Mexico, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Hospital Español de México, Centro Médico Nacional "20 de Noviembre" from the Instituto de Salud y Seguridad Social para Trabajadores del Estado, and Hospital Central Militar from January 1978 to December 2001 were studied.

[Non-erosive gastroesophageal reflux disease. Incidence of clinical forms, characteristics of esophageal exposure to acid and symptomatic correlations].

Background: It is estimated that up to 70% of community-based patients with heartburn have no evidence of esophageal mucosal injury or non-erosive gastroesophageal reflux disease (NERD). Studies in NERD patients using esophageal pH monitoring and symptom index (SI) have suggested different subgroups or clinical forms.

Objective: Our aim was to investigate frequency of different subgroups of patients with NERD according to esophageal pH-monitoring parameters and SI, and to determine esophageal acid exposure characteristics and the relationship between symptoms and acid reflux in NERD.

[Assay validation for determining nitrites and nitrates in biological fluids].

Introduction: Nitric oxide is an important modulator of numerous physiological and pathophysiological processes. An indirect form to detect NO production has been the quantification of its stable end products, nitrites and nitrates (NO2- + NO3-). These metabolites can be detected with a commercial kit, but it is somewhat expensive and not accessible to some laboratories in our country.