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Biomedical subjects

R A Matthay

Publications and source records attributed to R A Matthay.

At least 109 records · Page 6Linked to original sources
PubMed1980

Alveolar macrophage-derived chemotactic factor: kinetics of in vitro production and partial characterization.

Alveolar macrophages are the initial phagocytic cells that encounter foreign material and particulates deposited in the terminal airways. We have examined a mechanism by which these cells, after phagocytic challenge, may control or amplify the inflammatory response in lung parenchyma. Normal human alveolar macrophages (AM) were studied from eight subjects. With in vitro culture, AM produced and released two substances into culture media which have potent chemoattractant activity for blood polymorphonuclear granulocytes (PMN) and negligible activity for mononuclear cells. Release of these factors is maximally stimulated by aggregated human immunoglobulin (Ig)G or zymosan particles; however, simple adhesion of the macrophages to plastic surfaces is also sufficient to stimulate release of these chemotactic substances. The larger substance (10,000 daltons) is immunologically distinct from C5a and interacts with a different PMN membrane receptor than that known to exist for formyl-methionyl-leucyl-phenylalanine. Its chemotactic activity is sensitive to the enzymatic effect of trypsin. Although producing a single elution peak on gelfiltration chromatography, electrofocusing in polyacrylamide gels yielded five peaks of radioactivity. Chemotactic activity was localized to a fraction with a pI = 5.0. The smaller molecular weight substance has been less well characterized. Thus, the human AM can produce at least two factors which attract PMN and this capability may augment the local inflammatory response in the lung.

Cells, Cultured↗
PubMed1980

Acute and chronic effects of fire fighting on pulmonary function.

The acute and chronic effects of fire fighting on pulmonary function were studied in 54 fire fighters from Connecticut, 32 smokers and 22 nonsmokers. Baseline studies of maximum expiratory flow-volume curves while breathing air and a mixture of 80 percent helium and 20 percent oxygen revealed obstruction of the small airways in 35 percent (nine) of 26 smokers and 13 percent (two) of 15 nonsmokers. Cigarette smoking appears to be a major contributor to obstruction of the airways in fire fighters. In the nonsmoking group, disease of the small airways was present only in fire fighters with at least 25 years of fire fighting, and none of them had respiratory complaints. In seven fire fighters retested immediately following mild exposure to a fire in a building, no significant changes in pulmonary function were noted. One fire fighter trapped in a fire in a basement had a high level of carboxyhemoglobin (42 percent) and developed a severe obstructive ventilatory defect which persists 2 1/2 years after the fire. The significance of disease of the small airways in fire fighters with chronic exposure remains to be elucidated with long-term studies; however, acute significant exposure may be associated with irreversible pulmonary injury in fire fighters.

Adult↗
PubMed1980

Right and left ventricular exercise performance in chronic obstructive pulmonary disease: radionuclide assessment.

Right and left ventricular pump performance was assessed at rest and during upright bicycle exercise in 30 patients with chronic obstructive pulmonary disease and in 25 normal control subjects. Right ventricular and left ventricular ejection fractions were ascertained noninvasively using first-pass quantitative radionuclide angiocardiography. The normal ventricular response to exercise was at least a 5% absolute increase in the ejection fraction of either ventricle. In patients the predominant cardiac abnormality involved performance of the right ventricle. Right ventricular ejection fraction was abnormal at rest in eight patients. Twenty-three patients demonstrated an abnormal right ventricular response to submaximal exercise. Airway obstruction and arterial hypoxemia were significantly more severe in patients with abnormal right ventricular exercise reserve than in those with normal reserve. Abnormal left ventricular performance was infrequent either at rest (four patients) or during exercise (six patients). Thus, this radionuclide technique allows noninvasive assessment of biventricular exercise reserve in chronic obstructive pulmonary disease.

Adult↗
PubMed1979

Angiotensin convertase activities in human alveolar macrophages: effects of cigarette smoking and sarcoidosis.

Angiotensin I convertase activity has been found in human alveolar macrophages from normal volunteers and patients with pulmonary sarcoidosis. This activity is higher in the alveolar macrophages from smokers than from nonsmokers, and is even more elevated in sarcoid patients. The activity can be detected with both angiotensin I and bradykinin analogs and appears to require protein synthesis, but the enzyme is not secreted by alveolar macrophages in culture.

Granuloma↗
PubMed1979

First-pass radionuclide assessment of right and left ventricular performance in patients with cardiac and pulmonary disease.

First-pass radionuclide angiocardiography allows noninvasive determination of right and left ventricular performance from a single study. Analysis is made from the high frequency components of the regional radionuclide time-activity curves. Both regional and global ventricular performance can be assessed at rest and during exercise. Sequential studies can be performed to evaluate therapeutic interventions. This technique has been applied in a broad spectrum of patients with cardiac and pulmonary disease and has been shown to have major clinical impact.

Adult↗
PubMed1978

Assessment of cardiac performance with quantitative radionuclide angiocardiography: right ventricular ejection fraction with reference to findings in chronic obstructive pulmonary disease.

A reproducible noninvasive technique for measuring righ ventricular ejection fraction was developed using first pass quantitative radionuclide angiocardiography. Studies were obtained in the anterior position with a computerized multicrystal scintillation camera with high count rate capabilities. Right ventricular ejection fraction was calculated on a beat to beat basis from the high frequency components of the background-corrected right ventricular time-activity curve. In 50 normal adults, right ventricular ejection fraction averaged 55 percent (range of 45 to 65 percent). This radionuclide measure of right ventricular function was reproducible, with minimal inter- and intraobserver variability, and was sensitive to changes in inotropic state induced with isoproterenol. In 36 patients with chronic obstructive pulmonary disease, right ventricular ejection fraction ranged from 19 to 71 percent. All 10 patients with corpulmonale, as well as 9 additional patients, had an abnormal right ventricular ejection fraction. Arterial oxygen tension and forced expiratory volume were depressed significantly more in patients with abnormal right ventricular ejection fraction than in subjects with normal right ventricular function. There was no relation between abnormalities in right and left ventricular ejection fraction.

Adult↗
PubMed1978

Methoxamine-induced increase in afterload. Effect on left ventricular performance in chronic obstructive pulmonary disease.

With a radionuclide technique, left ventricular ejection fraction and stroke volume index were measured in the basal state and after the stress of a methoxamine-induced increase in afterload in 10 men with severe chronic obstructive pulmonary disease. The resting mean left ventricular ejection fraction was normal in all 10 patients. After an acute increase in resistance to left ventricular ejection with methoxamine, the left ventricular ejection fraction and the stroke volume index did not decrease significantly, even in the presence of cor pulmonale in 5 patients. Mean pulmonary capillary wedge pressure was normal before, and did not change significantly after, methoxamine infusion. The data suggest that latent left ventricular dysfunction is not present in this group of patients with severe chronic obstructive pulmonary disease.

Aged↗
PubMed1978

Pulmonary infections in the compromised host.

Immunocompromised hosts are predisposed to pulmonary infection with a wide variety of pathogens. A cooperative team effort is recommended to complete, in stepwise fashion, the procedures necessary to establish the specific cause of pulmonary infiltrates in the compromised host. The diagnostic approach needs to be individualized, and will depend in part on the urgency of the clinical situation and the skills available at the institution providing treatment.

Aged↗
PubMed1977

Bacteremic hemophilus influenzae pneumonia in adults. A report of 24 cases and a review of the literature.

Twenty-four cases of Hemophilus influenzae pneumonia diagnosed by positive blood or pleural fluid cultures are compared to 43 cases previously reported in the literatrue. Frequently associated illnesses in both series include alcoholism, chronic airways obstruction and preceding respiratory tract infection. Moderate temperature elevation and slight leukocytosis were common on admission in both groups. Chest roentgenograms in our series revealed both bronchopneumonia (75 per cent) and lobar consolidation (38 per cent). Pleural disease occurred frequently, with two empyemas noted on admission and nine additional effusions developing during therapy. Treatment of choice was ampicillin. All five patients who did not receive ampicillin died, whereas 16 to 19 who received this drug survived. High mortality (33 per cent) in our series may be attributed to the advanced age of the patients and the presence of associated illnesses. In addition, a 10 year review suggests a true increase in the incidence of H. influenzae pneumonia in adults.

Adult↗
PubMed1977

Cytotoxic drug-induced lung disease.

Cytotoxic drugs, principally bleomycin, methotrexate and busulfan, have been associated with pulmonary toxicity. Cytotoxic drug-induced lung disease may be difficult to establish with certainty because other causes of pulmonary disease are frequently present. We discuss the clinical, roentgenographic and histologic effects of the administration of bleomycin, methotrexate, busulfan and other cytotoxic agents on the lungs and suggest that these agents may also cause pulmonary malignancies. We note the importance of careful patient monitoring and withdrawal of a demonstrated offending agent.

Antibiotics, Antineoplastic↗
PubMed1977

Diagnostic fibreoptic bronchoscopy in the immunocompromised host with pulmonary infiltrates.

Nineteen immunocompromised patients with pulmonary infiltrates underwent diagnostic fibreoptic bronchoscopy with transbronchial forceps and brush biopsy. A specific diagnosis was obtained in 21/25 procedures (10/11 focal lesions and 11/14 diffuse legions). The most common diagnosis was infection, and organisms isolated included bacteria, fungi, Pneumocystis carinii, and herpes simplex. A pneumothroax requiring tube drainage occurred in two cases and mild lung parenchymal bleeding was noted in two others. It is concluded that fibreoptic bronchoscopy with forceps and brush biopsy can be performed safely with an excellent diagnostic yield in immunocompromised hosts with lung lesions. Supplemental oxygen should be administered during fibreoptic procedures in these patients and platelet transfusions should be given when thrombocytopenia is present.

Adult↗