Biomedical subjects

A da Costa

Publications and source records attributed to A da Costa.

5 recordsLinked to original sources

PubMed2001

Immunologic evaluation in infective endocarditis.

OBJECTIVE: To analyze the immune response in peripheral blood of patients with infective endocarditis. METHODS: We studied 10 patients with infective endocarditis, age range from 20 to 50 years-old, males and females, and 20 healthy subjects in the same age range. The diagnosis of the disease was based on the clinical picture, echocardiogram, and hemoculture based upon samples drawn and tested before the treatment started. The were no history of atopy or malnutrition, no autoimmune disease, and they were not using any immunosuppressant or antibiotic medication. RESULTS: The patients with endocarditis had significantly higher T and B lymphocyte, CD4+ and CD8+ cell counts, IgM and IgG serum levels, and C4 component of the complement than the control group; no significant difference concerning serum IgA and neutrophil oxidative metabolism; a significant decrease in C3, chemotaxis, and monocyte phagocytosis;cryoglobulins were detected in 66.6% of patients and they were formed by IgG, IgM, IgA, C3, and C4. CONCLUSION: The patients with infective endocarditis were immunocompetent in most sectors of immune response and, at a certain moment, an autoimmune component may be present.

Adult↗

PubMed1998

Use of the continuity equation for transesophageal Doppler assessment of severity of proximal left coronary artery stenosis: a quantitative coronary angiography validation study.

OBJECTIVES: We tested the value of transesophageal Doppler echocardiography (TEDE) for quantitating proximal left coronary artery (LCA) stenosis by using the continuity equation. BACKGROUND: The continuity equation applied to a stenosis states that the ratio of the time-velocity integral (TVI) of prestenotic to stenotic flow velocities is equal to the ratio of stenotic to prestenotic cross-sectional areas. TEDE allows the measurement of coronary blood flow velocities within the proximal part of the LCA. METHODS; Forty-one patients with a stenosis of the proximal or mid left anterior descending coronary artery or with a nonostial stenosis of the left main coronary artery were studied. Coronary flow velocities were recorded by TEDE guided by color flow imaging. Prestenotic velocities were recorded by pulsed Doppler echocardiography and transstenotic velocities were recorded by pulsed or high pulse repetition frequency or continuous wave Doppler echocardiography. The prestenotic and transstenotic diastolic TVIs were calculated and the TEDE-derived percent area stenosis was calculated as (1 - TVI ratio) x 100. Quantitative angiography lesion analysis was performed using a computer-assisted automated edge-detection system. RESULTS: TEDE recordings were successful in 35 of the 41 patients. A good linear correlation was found between TEDE and quantitative angiographically derived percent area stenosis (r = 0.89, p = 0.0001, SEE 5.7). However, TEDE measurements underestimated the actual percent area stenosis (slope of regression 0.54). A better agreement (slope 1.08) was obtained after dividing prestenotic velocity by 2 in the continuity equation, based on the assumption of a parabolic cross-sectional velocity profile in the prestenotic segment. CONCLUSIONS: TEDE may be used for quantitating stenosis of the proximal part of the LCA with the use of a modified continuity equation that takes into account the parabolic velocity profile in the normal prestenotic segment.

Adult↗

PubMed1998

Respiratory health and immunological profile of poultry workers.

OBJECTIVES: To examine work-related respiratory symptoms in poultry workers, and to test for immunologically mediated responses to poultry-related agents. DESIGN: A cross-sectional survey of differentially exposed poultry workers and unexposed blue-collar workers. SETTING: Three poultry farms and a poultry plant in Gauteng (exposed workers) and a municipal workers' clinic in Johannesburg (controls). PARTICIPANTS: 134 poultry workers (85.4% of all eligible workers) and 122 controls (> 95% response rate). OUTCOME MEASURES: Respiratory symptoms plus allergy and hypersensitivity to poultry agents identified by skin-prick tests, and by the presence of specific IgE and IgG enzyme-linked immunoflow assay and nonspecific (radial immunodiffusion) antibodies. RESULTS: Smoking habits and atopic status were similar in the poultry workers and the controls. Symptoms were very common in poultry workers, for example work-related cough in 32% and work-related wheeze in 23% of highly exposed workers. Significantly more poultry workers than controls complained of chest symptoms (increasing with increasing exposure), and of eye, skin and nose irritation at work. More poultry workers than controls had symptoms consistent with asthma (e.g. 3%, 4%, 13% and 11% in controls and subjects with low, medium and high exposure, respectively), and symptom complexes associated with organic dust exposure. Five poultry workers had positive skin-prick test reactions to poultry-specific antigens, but none of the unexposed controls reacted. More poultry workers than controls had positive immunodiffusion test reactions to chicken feed, feathers and serum, and IgE to chicken faeces. There was no association between immunological status and respiratory symptoms. CONCLUSION: We found a very high prevalence of exposure-related symptoms in poultry workers; improved hazard control is strongly indicated. Tests of allergy and hypersensitivity were associated with exposure, but not with disease. The possibility of useful tests of sensitisation has not been excluded; a prospective study design is likely to be more rewarding than cross-sectional approaches such as in this study.

Air Pollutants, Occupational↗

PubMed1989

Functional and immunological concentrations of alpha 2-macroglobulin compared in plasma of subjects without alpha 1-protease inhibitor deficiency.

Alpha 2-Macroglobulin concentrations as measured by a functional assay and by laser nephelometry with antibody precipitation were compared for 67 outpatients at a respiratory clinic and 30 blood-donor control subjects with no respiratory disease. In both groups, concentrations of alpha 1-protease inhibitor in plasma, as measured by laser nephelometry, were within the normal reference interval. A reasonable correlation (r = 0.70) was obtained between results of functional assays and of laser nephelometry for the control individuals. For patients with pulmonary disease the correlation between the two assay methods was poorer (r = 0.53). We conclude that the functional assay of plasma is the better method for detecting abnormal concentrations of alpha 2-macroglobulin in patients with lung diseases.

Adult↗

PubMed1988

Assessment of tissue reaction at suture knots; an adaptation of Sewell's scoring system.

From a theoretical point of view and from reported animal work the knot side should be considered the most relevant part of the suture loop for studying inflammatory foreign body reaction. In the present study a semi-quantitative histological assessment of inflammatory tissue reaction around the knots of implanted sutures is presented. To test the reliability of this method an animal model was used in which two suture materials with well-known differences in tissue reactivity were studied. Differences in tissue response around the knots between these materials proved to be highly significant statistically (tissue reactivity score (TRS) 44.17 vs. 58.71: p less than 0.001). No differences in TRS could be demonstrated between different localizations in the anterior abdominal wall of male Wistar rats. Implications of these findings with respect to future studies are discussed.

Abdominal Muscles↗