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Biomedical subjects

R G Benjamin

Publications and source records attributed to R G Benjamin.

5 recordsLinked to original sources
PubMed1989

Removal of bronchial secretions by two-phase gas-liquid transport.

Net outward wave motion of secretions from airways by two-phase gas-liquid transport is favored by higher airflow during expiration than inspiration. This can be accomplished by IRV in which the controlled mode of mechanical ventilation is adjusted such that the inspiratory cycle is prolonged and the expiratory phase is shortened. Studies were done on six anesthetized, nasally intubated sheep. Simulated mucus was instilled into the bronchi at 15-min intervals during I-E ratio of 1:2.7, 1.9:1, and 3:1. The IRV modes of 1.9:1 and 3:1 promoted transport of simulated mucus outward. Neither systemic blood pressure nor cardiac output were altered by IRV. Thus, IRV might be useful in the management of excessive bronchial secretions in mechanically ventilated patients. However, clinical trials of IRV should take into account its potential for producing adverse hemodynamic effects and barotrauma in patients with compromised cardiac function due to auto-PEEP attendant with its usage.

Animals↗
PubMed1984

Evaluation of mycobacterial antigens in an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of tuberculosis.

Five mycobacterial antigens were compared in an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of tuberculosis. The antigens studied were an unheated sterile culture filtrate of Mycobacterium tuberculosis, tuberculin purified protein derivative (PPD) from M. tuberculosis (PPDa), purified cytoplasmic protein antigens 5 and 6 from M. tuberculosis, and a PPD prepared from M. kansasi (PPDk). Multivariate analysis of variance showed that geometric mean titres obtained with each of the antigens in ELISA were significantly different in tuberculosis patients and in control groups. The covariation of the ELISA results with the five antigens was highly interdependent. Analysis of receiver operating characteristics revealed that the most accurate test was obtained with antigen 5. M. tuberculosis PPD, M. tuberculosis antigen 6, and M. tuberculosis culture filtrate were, in descending order, less accurate.

Antibodies, Bacterial↗
PubMed1984

Pulmonary function in sarcoidosis.

Pulmonary function testing provides an important insight into the pathophysiology in patients with sarcoidosis. Major functional abnormalities in this disease include decreased diffusing capacity, lung compliance and lung volumes. Arterial oxygen desaturation with exercise is common. Airways obstruction may occur as an isolated finding or be superimposed on the interstitial process. The activity of the disease cannot be well determined by pulmonary function tests but serials testing is helpful in detecting progression or improvement.

Airway Resistance↗
PubMed1982

Serodiagnosis of tuberculosis using the enzyme-linked immunoabsorbent assay (ELISA) of antibody to Mycobacterium tuberculosis antigen 5.

The serologic response to purified mycobacterial antigen 5 was examined using an enzyme-linked immunoabsorbent assay in 75 patients with pulmonary tuberculosis and 150 control subjects. Two patient and 6 control groups were studied. The serums from the patient groups had significantly higher IgG antibody concentrations than infected control subjects with good specificity. In patients living in low prevalence areas where the results of skin tests in the majority of the population are negative, an antibody titer greater than or equal to 1:40 would have a 95.8% specificity for active disease. For patients living in a high prevalence area where the results of skin tests in the majority of the population are positive, then an antibody titer greater than or equal to 1:40 would have a 79.9% specificity for active disease. Serums from patients with active nontuberculous mycobacterial infection had intermediate mean titers.

Antibodies, Bacterial↗