Search PubMed⌕ Search

Biomedical subjects

R B George

Publications and source records attributed to R B George.

At least 73 records · Page 4Linked to original sources
PubMed1985

Mycobacterial, fungal, actinomycotic, and nocardial infections of the pleura.

Granulomatous pleuritis is relatively common, comprising about 10 per cent of all pleural effusions. A search for the etiologic agent is important since mycobacteria, fungi, and the higher bacteria Actinomyces and Nocardia produce similar clinical, radiographic, and pleural fluid findings. The appropriate use of diagnostic tests including pleural biopsy and serologic techniques is discussed, as are current approaches to the management of these infections.

Actinomycosis↗
PubMed1985

Managing asthma and COPD in patients with cardiovascular disease.

Sideris et al followed 91 patients aged 25 to 82 (mean age 55) with respiratory failure due to severe asthma, emphysema, or chronic bronchitis. They found that patients with ventricular arrhythmias were significantly older than those without them. Although arrhythmias associated with myocardial infarction are managed primarily with drug therapy, those associated with acute respiratory failure respond best to adequate oxygenation and correction of metabolic and hemodynamic abnormalities.

Adult↗
PubMed1984

Significance of serum antibodies to Histoplasma capsulatum in endemic areas.

To evaluate the specificity of serologic tests for histoplasmosis in an endemic area, we studied sera from 104 consecutive healthy blood donors, testing for antibodies to either histoplasmin or Histoplasma yeast antigen, using complement fixation (CF), radioimmunoassay (RIA), and radial immunodiffusion (ID). Twenty-five subjects (24%) had CF antibody titers of 1:8 or 1:16 to one or both antigens; none had titers above 1:16. Nine subjects (9%) had RIA antibody titers of 1:8 or higher. No titers above 1:8 were found using the yeast antigen; five subjects had titers of greater than 1:16 to histoplasmin using RIA. No precipitin bands were found in any of these subjects. The results of four previous studies in endemic populations yielded similar or lower incidences of positive tests. CF antibody titers to either antigen, RIA antibody titers to yeast antigen of 1:32 or greater, or precipitin bands are rare in persons who live where histoplasmosis is endemic.

Adolescent↗
PubMed1984

Exercise capacity as a predictor of post-thoracotomy morbidity.

Although severe impairment on routine pulmonary function tests will identify patients with a high post-thoracotomy morbidity, cardiopulmonary complications often develop in patients with only a mild-to-moderate impairment in pulmonary function. To determine whether the preoperative exercise capacity can prospectively identify those at risk of developing complications, 22 patients scheduled for thoracotomy (mean age, 55.7 +/- 2 yr) underwent an incremental exercise test on a cycle ergometer to determine their maximal O2 uptake (VO2max) prior to thoracotomy. Routine pulmonary function tests were performed and postoperative forced expiratory volume in one second (FEV1) was predicted from split function perfusion lung scan in all subjects. Eleven of the 22 patients had no cardiopulmonary complications postoperatively. The age, history of prior cardiovascular disease, degree of impairment on routine pulmonary function tests, and predicted postoperative FEV1 were similar in those who did and those who did not experience complications. However, those without complications had a significantly higher VO2max than did those who experienced complications (22.4 +/- 1.4 versus 14.9 +/- 0.9 ml/kg/min, p less than 0.001). Only 1 of 10 patients with a VO2max greater than 20 ml/kg/min had a complication, whereas all 6 patients with a VO2max less than 15 ml/kg/min had a complication. We conclude that exercise testing is a useful adjunct in the evaluation of operative risk for thoracotomy.

Adult↗
PubMed1984

Postural hypoxemia in the postpneumonectomy patient.

A patient with platypnea and orthodeoxia after right pneumonectomy is described. Cardiac catheterization revealed arterial desaturation in the upright position associated with increased right to left intracardiac shunting through a patent foraman ovale. The absence of a pressure gradient between the left and right atrium in either the supine or sitting position indicated that the orthodeoxia resulted from an increase in streaming of blood from the inferior vena cava to the left atrium caused by mechanical distortion of the interatrial septum.

Cardiac Catheterization↗
PubMed1984

Tissue morphology of Histoplasma capsulatum in acute histoplasmosis.

Reports of histopathology in acute histoplasmosis are rare. A case of fulminating acute histoplasmosis with hematogenous dissemination is described in which Histoplasma capsulatum was identified in transbronchial biopsy. This report represents the first morphologic description of H. capsulatum within human pulmonary tissue in the early phase of acute histoplasmosis. The yeast forms observed were of typical size, but they were present within the alveoli and were budding. No tissue granulomata were noted. This unusual morphology is in sharp contrast to the classic description of the organism in tissues and presented diagnostic difficulties, which are discussed in this report. Hematogenous dissemination is considered to be an important part of the pathogenesis of the disease, but it is rarely documented during the symptomatic phase of acute histoplasmosis. Cultural documentation of hematogenous dissemination was obtained in this patient. These observations stress the importance of obtaining culture material from extrapulmonary sites early in the course of acute histoplasmosis when a specific diagnosis is necessary.

Acute Disease↗
PubMed1984

The spectrum and significance of pleural disease in blastomycosis.

To determine the incidence and significance of pleural disease in blastomycosis, we reviewed the chest roentgenograms and medical records of 26 consecutive patients with biopsy- or culture-proved Blastomyces dermatitidis infection. Twenty-three of the 26 (88 percent) had radiographic evidence of blastomycotic pleural disease. Pleural reaction that regressed on therapy was mild (less than 1.0 cm thickening on EPA chest film) in 12. More extensive pleural thickening (1.5 to 3.0 cm) was observed in five, while four had effusions, and two had pneumothoraces. The 15 patients with mild or no visible pleural thickening were considered to have minor pleural involvement, while the 11 patients with greater than 1.5 cm pleural reaction, effusions, or pneumothoraces were considered to have major pleural disease. The ages, incidence of serious underlying disorders, and extra-thoracic dissemination were similar in both groups. Chest pain was more frequent in those with major pleural involvement (8/11 vs 4/15, p = 0.02), and their white blood cell count (14,300 +/- 1,200 c/mm3) was significantly higher than that of those with minor pleural involvement (10,600 +/- 1400, p less than 0.05). All of the patients with minor pleural disease responded to amphotericin therapy, but four of 11 (36 percent) with major pleural disease had an unfavorable outcome (relapse = two, death = two) (p = 0.02). In these patients with blastomycosis, pleural involvement was extremely common. Major pleural disease was associated with an adverse prognosis and may be an indication for prolonged therapy.

Adult↗
PubMed1984

Anticholinergics, cromolyn, and other occasionally useful drugs.

In asthmatics who are not controlled with beta-adrenergic agonists, theophylline and corticosteroids, the addition of anticholinergics may be beneficial. Cromolyn and the calcium-channel blocking agents are useful in preventing asthma attacks in some patients. Some other agents that have been proposed for the treatment of asthma are discussed briefly.

Adrenergic alpha-Antagonists↗
PubMed1983

Invasive fungal infections. The use of serologic tests in diagnosis and management.

Serologic tests are useful in providing a presumptive diagnosis of invasive fungal infection, allowing early institution of specific therapy. The judicious use of these serologic tests for circulating antibodies or antigens also may aid in analyzing response to treatment and in assessing prognosis. This review summarizes the currently available serologic tests for common invasive mycoses and discusses their relative usefulness and reliability.

Aspergillosis↗
PubMed1983

The bronchodilator response to inhalation of increasing doses of aerosolized albuterol.

Forty-four asthmatic patients were treated on separate days with increasing doses of albuterol in four double-blind studies that included placebo controls. Twenty-six subjects received one, two, four, six, and eight inhalations from a metered dose inhaler; 18 subjects received 1.25, 2.5, 5, 10, and 15 mg delivered by IPPB. There was a significant linear relationship in both groups between the maximum increase in FEV1 and the log dose of albuterol. The response to four, six, and eight inhalations from the metered dose inhaler was significantly greater than the response to one inhalation, and the response to 15 mg by IPPB was significantly greater than the response to any other dose by IPPB. The results suggest that in many patients maximum possible bronchodilation is not achieved by customarily recommended doses.

Administration, Intranasal↗
PubMed1983

Effects of labetalol in hypertensive patients with chronic obstructive pulmonary disease.

Labetalol is a new adrenergic antagonist with both alpha- and beta-blocking effects. To evaluate its usefulness in the treatment of hypertension in patients with coexisting chronic obstructive pulmonary disease (COPD), labetalol was administered in gradually increasing doses to a group of 11 patients with mild-to-moderate hypertension and COPD with a mild reversible component. Ten patients given hydrochlorothiazide served as control subjects. Blood pressure was controlled in seven of the 11 patients given labetalol and in six of the ten patients given hydrochlorothiazide in dosages up to 1,200 mg/day and 150 mg/day, respectively. No significant changes occurred in the FEV1 or FEF25-75% two hours after the administration of the maximum dose of either drug or after exercise on the same day. Labetalol was well tolerated in the doses given.

Adult↗
PubMed1983

Serial pulmonary function in patients with acute heart failure.

This study delineates the effects of congestive heart failure on routine pulmonary function tests and assesses the changes in pulmonary function as congestive heart failure was treated. Twenty-eight patients had spirometry, lung volumes, and diffusing capacity measurements initially and at frequent intervals after their initial hospitalization for congestive heart failure. Initially the patients had both obstructive (mean forced expiratory volume in 1 s [FEV1], 48.2% +/- 13% predicted) and restrictive (mean forced vital capacity [FVC], 5.6% +/- 15.7% predicted) ventilatory dysfunction, but a normal carbon monoxide diffusing capacity. With treatment, pulmonary function rapidly improved initially and there was no further significant improvements in the mean pulmonary function after two weeks of treatment. However, there was marked interindividual variability and several patients took months to reach their best level of pulmonary function. Even with treatment, the patients retained evidence of obstructive ventilatory dysfunction and at the time of their best spirometry 53% (8/15) of nonsmokers still had an abnormally low FEV1/FVC ratio.

Aged↗
PubMed1981

Radioimmunoassay: a sensitive screening test for histoplasmosis and blastomycosis.

Currently available serologic tests for histoplasmosis and blastomycosis have limited sensitivity. In order to develop a more sensitive screening test, the radioimmunoassay (RIA) technique was adapted to detect circulating antibodies to Histoplasma mycelial, Histoplasma yeast, and Blastomyces yeast antigens. Results were compared with those of complement fixation (CF) using serums from 4 groups of subjects. Group 1 (n = 104) consisted of consecutive healthy blood donors from an endemic area. Group 2 (n = 8) had active histoplasmosis and Group 3 (n = 12) had active blastomycosis. Group 4 (n = 30) had other chronic lung diseases. Among Group 1 subjects, elevated titers to at least 1 antigen were found in 13% using RIA and 21% using CF. Only 50% of patients with active mycoses (Groups 2 and 3) had elevated CF titers to a homologous antigen, whereas the RIA test was positive in 19 of 20 patients (95%). Elevated titers to 1 or more antigens was found in Groups 1 and 4, and frequent cross-reactions among the antigens occurred with both tests, indicating low specificities for both RIA and CF. The RIA is a sensitive and rapid screening test for histoplasmosis and blastomycosis, and a negative RIA using the 3 antigens tested makes the diagnosis of active infection very unlikely in immunologically competent patients.

Adolescent↗
PubMed1981

Nitrobule tetrazolium test in the diagnosis of pleural effusions.

This study evaluated the diagnostic utility of the nitroblue tetrazolium test on pleural fluid. Pleural fluids from 62 patients, including nine with congestive heart failure, 27 with malignant neoplasms, nine with tuberculosis, 14 with pneumonia, and three with collagen vascular disease, were studied. Results of nitrobule tetrazolium were tabulated for each patient for three different cellular types (polymorphonuclear leukocytes, small lymphocytes, and mononuclear cells other than small lymphocytes). The three patients with collagen vascular disease had very high scores on the nitrogen tetrazolium test for all three cellular types. Their average scores were higher than were those of 57 of the other 59 patients. The nitroblue tetrazolium test on pleural fluid was not useful in separating patients with congestive heart failure, pneumonia, malignant neoplasms, or tuberculosis. The results on the nitroblue tetrazolium test did not help to identify those patients with pneumonia who eventually required tube thoracostomy. From this study, we conclude that the nitroblue tetrazolium test on pleural fluid is of limited use diagnostically but may help to identify those individuals with collagen vascular disease involving the pleura.

Collagen Diseases↗