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Biomedical subjects

A Ruiz

Publications and source records attributed to A Ruiz.

365 records · Page 21Linked to original sources
PubMedDate not supplied

[Intestinal helminthiasis in the Mexican Republic].

Very few uncertain and not trustworthy reports about the frequency of intestinal helminthiases found in humans have been made in México. However, with the few trustful studies carried out from 1981 to 1992, it is possible in México to verify that ascariasis, trichuriasis, hookworm infection and hymenolepiasis are present with significant percentages of infected people 11.2%, 1.7%, 0.15% and 1.8%, respectively. With the information obtained from the researches analyzed in this article, one can conclude that human infections by intestinal helminths in México, at the present time are almost as frequent as in past decades. Without any doubt, this occurs because still remain the factors that contribute to the persistence and spreading of the intestinal helminths, such as fecalism, poor hygienic and alimentary habits within deficient environmental sanitary conditions.

Adolescent↗
PubMedDate not supplied

Histopathologic prognostic score in colorectal adenocarcinomas.

OBJECTIVE: To analyze the prognostic value of a set of pathological variables after curative resection for large bowel adenocarcinoma and to test a prognostic score derived from factors with independent effect. PATIENTS AND METHODS: The study is based on data from 292 consecutive unselected patients (B-C Astler-Coller stages). Histopathological features were evaluated prospectively on the resected primary tumors. Relationship between these factors and risk of recurrence was assessed by a Cox's proportional regression analysis. RESULTS: Four variables retained independent prognostic significance: extent of bowel wall invasion, peritumoral lymphocytic infiltration, number of positive nodes and vascular invasion. A prognostic score based on the regression coefficients attained by such variables was developed. This system revealed four prognostic groups. Group I included 14% of patients, with 94% 5-year disease-free survival. These figures were: 35% and 60% in group II; 43% and 46% in group III; and 7% and 24.4% in group IV. Histopathologic score applied to bearers of Astler-Coller B2 tumors permitted the identification of two populations, one characterized by a low risk of relapse and another with high risk (p = 0.002). CONCLUSION: A prognostic score based in the evaluation of four histopathologic parameters concerning the tumor phenotype enables the identification of groups of patients at risk of relapse after curative resection for colorectal adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Thallium-201 brain SPECT of lymphoma in AIDS patients: pitfalls and technique optimization.

PURPOSE: Our aim was to examine the 201Tl-SPECT scans in AIDS patients with focal CNS lesions to identify those studies with a false-positive or false-negative result to determine any potential pitfalls in interpretation as well as to suggest methods for technique optimization. METHODS: We retrospectively reviewed the charts of 162 AIDS patients with cerebral mass lesions on 201Tl-SPECT studies. One hundred sixty-one patients had CT examinations, of which 50 also had MR studies. One patient had MR imaging without CT. Those patients in whom the diagnosis by 201Tl-SPECT did not correspond with the known pathologic or clinically proved diagnosis were then singled out and their CT, MR, and 201Tl-SPECT studies were reviewed, including blinded interpretation of the 201Tl-SPECT scans alone and alongside the corresponding CT and MR examinations. Studies were examined for lesion morphology, size, location, enhancement pattern, and presence of necrosis. The review of the 201Tl-SPECT studies included both a qualitative approach (subjective analysis of the scans for areas of abnormally increased uptake) and a quantitative approach (comparison of lesion activity versus activity within a reference standard, such as the scalp). RESULTS: Sensitivity and specificity of 201Tl-SPECT in depicting lymphoma were 100% and 93%, respectively, based on the initial qualitative analysis. Fifty-one patients had positive 201Tl-SPECT results, of whom 43 were determined to have lymphoma (four by biopsy/autopsy, 39 by clinical and radiologic findings). Upon reevaluation with both a quantitative and qualitative approach, those studies initially interpreted as positive in patients without lymphoma (false positives) were found to be negative. CONCLUSION: Brain 201Tl-SPECT is an effective study in the diagnosis of CNS lymphoma in AIDS patients. Specificity can be increased by routinely performing a quantitative analysis of all lesions.

Brain↗
PubMedDate not supplied

Bronchoalveolar lavage in smokers: quantification of alveolar macrophages and neutrophils as markers of bronchial obstruction.

Increased concentrations of neutrophils and alveolar macrophages are recovered in the bronchoalveolar lavage (BAL) of smokers compared with non-smokers. We designed a study to determine the relationship between neutrophils and alveolar macrophages recovered by BAL and the degree of air-flow obstruction, measured by spirometry (chronic air-flow obstruction was defined as: FEV1 < 80% of predicted and FEV1/FVC ratio < 70% of predicted) in healthy smokers. We found a significant correlation between spirometric values and the number of neutrophils and alveolar macrophages in BAL fluid obtained from healthy smokers. Our findings suggest that counts of 13-15x1000 neutrophils/ml and/or 430-450x1000 alveolar macrophages/ml in BAL fluid could be used as markers of air-flow obstruction in smokers.

Adult↗