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Biomedical subjects

H A Lyons

Publications and source records attributed to H A Lyons.

At least 19 recordsLinked to original sources
PubMed1986

Pulmonary tuberculosis and bronchocentric granulomatosis.

Bronchocentric granulomatosis (BG) is an uncommon inflammatory lesion of unknown etiology defined on morphologic grounds by the presence of necrotizing granulomata centered on bronchi and bronchioles. We report the typical pathologic features of BG in a patient with tuberculosis. Mycobacterial and other types of infection should be excluded by appropriate stains and cultures in all patients with BG on lung biopsy, especially those who are nonasthmatic.

Adult↗
PubMed1983

Adult respiratory distress syndrome as a cause of death in pneumococcal pneumonia. Report of ten cases.

The Pneumococcus continues to be a common cause of infectious pneumonia; however, the cause of death in pneumococcal disease remains obscure. Ten patients are described who developed the adult respiratory distress syndrome (ARDS) secondary to pneumococcal pneumonia. The patients are young (median age, 33 years) and leukopenic (median white blood cell count, 2.1 cells/cu mm) and have a mortality of 50 percent (five patients). It is postulated that pulmonary sequestration of leukocytes may play a role in the pathogenesis of ARDS secondary to pneumococcal disease. Four different pneumococcal capsular subtypes (9V [68]; 9A [33]; 4; 3) were found capable of causing ARDS. The currently available pneumococcal vaccine does not contain two of the capsular subtypes associated with ARDS.

Adult↗
PubMed1981

Exercise-induced asthma - a comparison between two modes of exercise stress.

Two types of treadmill exercise were performed by 10 asthmatics (mean age 32.4 +/- 8.9 years). One type of exercise was a steady state, submaximal effort lasting approximately 7 min. The other was a short, supramaximal effort designed to exhaust the subjects within 50 s. Ventilatory studies as well as gas exchange, arterial blood lactate (LA) and pH were measured pre- and post-exercise. The submaximal exercise caused the expected increase in Raw (19%) and a decrease in FEV1 (21%) and MMEF (20%) measured 10 min following exercise. In contrast, only the MMEF was reduced (26%) at 10 min after the short-exhaustive exercise. It was concluded that short (less than 1 min) and highly intense exercise challenge may cause a drastic fall in MMEF with no changes in FEV1.0 or Raw. It is postulated that the unequal ventilatory response to the two exercise modes is responsible for a greater respiratory heat loss during the long-submaximal exercise and consequently for the greater obstruction of the large airways. In addition the short-exhaustive exercise performed in this study may serve as a simple and accurate tool for detecting small airway obstruction as measured by the MMEF.

Adult↗
PubMed1981

Mortality in sarcoidosis. A changing pattern of the causes of death.

Forty-one deaths occurred among 1,090 patients with the clinical diagnosis of sarcoidosis between 1960 and 1977. Thirteen patients died of causes unrelated to sarcoidosis, whereas death was related to sarcoidosis in 28 patients (68%). The most prevalent lesion leading to death was advanced pulmonary involvement (22/28 patients or 78%) with various late complications: cardiorespiratory failure, gram-negative pneumonias, fungal infections. The average clinical course among these 22 patients was 10 years from the onset of the disease. The average age at death was 39 years. Patients who died of central nervous system and cardiac sarcoidosis were younger, and their clinical course was shorter. Subclinical sarcoidosis does not seem to affect life span. Autopsy in 25 patients showed systemic sarcoid lesions in all, including asymptomatic patients and those presenting with clinical manifestations limited to the CNS and the heart. The discrepancy implies difficulty in making the diagnosis, and suggests the need of intensive diagnostic work-up. Improved medical therapy, particularly the control of infections and management of cardiorespiratory failure, has resulted in a protracted clinical course and a changing pattern of the causes of death in sarcoidosis.

Adult↗
PubMed1979

A comparative study of bronchodilator effects of carbuterol and ephedrine.

The bronchodilator effect of carbuterol hydrochloride, a new adrenergic agonist, was compared with that of ephedrine sulfate in 12 patients with bronchial asthma. A 2-mg dosage of carbuterol hydrochloride, three times daily, was used in comparison with a 25-mg dosage of ephedrine sulfate, three times daily. The drugs were orally administered for ten-day periods in a double-blind, randomized manner. After carbuterol therapy, the mean increases in forced expiratory volume in one second and midmaximal expiratory flow rate were significantly greater in a four-hour period than those noticed with ephedrine. A decrease in bronchodilator response to both drugs was noticed on the tenth day. No side effects were noticed with carbuterol at the aforementioned dosage. The results of our study indicate that carbuterol is a safer and more effective bronchodilator than ephedrine.

Administration, Oral↗
PubMed1979

P pulmonale in status asthmaticus.

We studied 129 patients during acute, severe asthmatic attacks. Electrocardiograms showed P pulmonale in 49% of patients who had an arterial carbon dioxide tension (PaCo2) greater than or equal to 45 mm Hg and an arterial pH less than or equal to 7.37, whereas P pulmonale was present in only 2.5% of asthmatics who had a PaCO2 less than or equal to 44 mm Hg and a pH greater than or equal to 7.38 (p less than 0.001). P wave and QRS axes were 79 +/- 8 degrees and 80 +/- 20 degrees, respectively, in the presence of P pulmonale. When P pulmonale disappeared, the P wave and QRS axes shifted significantly to the left (p less than 0.001). Electrocardiographic P pulmonale persisted 12 to 60 hr after correction of hypoxemia, hypercapnia, and acidosis. In 7 patients with P pulmonale and respiratory acidosis, cardiac catheterization demonstrated normal artery pressures (PAPs) measured relative to atmospheric pressure. In 12 of these peak inspiratory pulmonary artery transmural pressures (PATPs) were increased. Since increased right heart transumural pressures could result in chamber distention, these data are consistent with the hypothesis that reversible P pulmonale in status asthmaticus is explainable on the basis of markedly negative tidal pleural pressures and increased right heart transmural pressures.

Adolescent↗
PubMed1979

Collateral ventilation in excised human lungs.

Collateral ventilation was determined in 13 isolated human lungs obtained at postmortem. These included lungs from patients with pneumonia (2 cases), metastatic breast carcinoma (3), emphysema (5), pulmonary fibrosis (2) and hemorrhagic abscess (1). The amount of collateral ventilation was variable and related to the pathological process within the lung. Flow and resistance of collateral pathways were determined for each studied lung. Demonstration of collateral flow was made with the use of 133Xe and recorded by radiographic imaging. Further demonstration of the collateral pathways was done by use of 1 micrometer sized particles of tantalum. Histological examination showed tantalum dust to accumulate at gaps in the alveolar wall at the lobar junction and to pass through this area. Although the sample population is small, no correlation was found for age and the amount of flow through the channels. This study demonstrated that alveolar pores play a role in collateral ventilation. No collateral flow was observed in six pediatric lungs tested. It is likely that collateral ventilation is an acquired phenomenon in humans.

Aged↗
PubMed1979

Pulmonary sarcoidosis: roentgenographic, functional, and pathologic correlations.

Discrepancies were observed between functional (PFT), chest roentgenographic, and open lung biopsy findings (granulomata, interstitial pneumonitis, angiitis, and fibrosis) in 81 patients with clinical diagnosis of sarcoidosis. A combination of normal PFT and Type 1 roentgenographic findings (hilar lymphadenopathy) was associated with minimal lung lesions without fibrosis. Type 1 findings alone did not preclude extensive lesions or fibrosis. Advanced roentgenographic and PFT abnormalities correlated with the presence of extensive lung lesions. The pulmonary diffusing capacity correlated best with specific and overall lung pathology, and roentgenographic types. Only this test differentiated the extent of granulomata and the roentgenographic types. Moderate degrees of other pathologic changes were not distinguished by any other PFT. Degrees of overall lung pathology correlated with an individual PFT and most significantly with overall PFT (p less than 0.001). Serial studies of PFT are a practical and valuable means for assessment of the disease process in sarcoidosis.

Adolescent↗
PubMed1978

Tuberculous mediastinal lymphadenitis in the adult.

The authors present the roentogenological findings and response to treatment of 10 patients with tuberculous mediastinal lymphadenitis (TML). The clinical presentation is usually nonspecific except for the positive tuberculin skin test. The roentgenographic appearance varies but very often includes right tracheobronchial involvement. Tissue diagnosis is often necessary to establish the diagnosis. Since the epidemiology of tuberculosis is shifting, TML will be encountered more frequently in the adult.

Adolescent↗
PubMed1978

Indications for the use of tranylcypromine and trifluoperazine (Parstelin).

Thirty-two patients were treated with the combination of tranylcypromine and trifluoperazine (Parstelin). The patients fell into 3 clinical groups, namely, endogenous depression (7 patients), neurotic depressive reaction (10 patients) and phobic anxiety with some depressive features (15 patients). Satisfactory response was found in 10 out of the 15 patients with phobic symptoms. The response in the other 2 groups was not significant. Side effects were troublesome in the neurotic depressive reaction group. In the phobic group the symptoms of the patients who responded were inclined to recur when the treatment was discontinued. It is considered that it is a useful preparation in the treatment of some phobic patients, but one must expect that the patients are likely to have to remain on the drug for long periods of time.

Adult↗
PubMed1978

Nongranulomatous interstitial pneumonitis in sarcoidosis. Relationship to development of epithelioid granulomas.

Nongranulomatous, nonspecific interstitial pneumonitis was a predominating or prominent histopathologic finding in 62 percent of 128 granuloma-containing specimens from open lung biopsies obtained from patients with sarcoidosis. Data from this study, combined with observations by others on the evolution of experimentally induced granulomas, indicate that interstitial pneumonitis represents a very early lesion, possibly the initial lesion, in pulmonary sarcoidosis. Because of the relatively large error of sampling inherent in the currently increasing practice of obtaining small specimens for lung biopsy via the flexible fiberoptic bronchoscope, we anticipate that interstitial pneumonitis will be seen as the only histopathologic finding in these specimens with increasing frequency. It is therefore important to recognize that interstitial pneumonitis is a characteristic, although nondiagnostic, morphologic feature of pulmonary sarcoidosis.

Adolescent↗