Richard E. Brashear

Pheochromocytoma as an Inherited Abnormality

ALTHOUGH the first pathological description of pheochromocytoma, by Frankel,1 appeared in 1886, it was not until 1922 that the association of pheochromocytoma and paroxysmal hypertension was descri...

Hemodynamic effects of elevated cerebrospinal fluid pressure: alterations with adrenergic blockade

The cardiovascular effects of elevated cerebrospinal fluid (CSF) pressure were studied in 18 dogs, 6 in a control group, 6 after alpha adrenergic blockade, and 6 after beta adrenergic blockade. Vascular pressures did not change until CSF pressure was increased from 100 mm Hg to 200 mm Hg. In the control group, the aortic, pulmonary arterial, wedge, and right atrial pressures increased significantly. Cardiac output, heart rate, and stroke volume increased but systemic and pulmonary vascular resistances did not change. In the alpha adrenergic blockade group, vascular pressures did not increase after elevation of CSF pressure. Cardiac output increased or did not change, stroke volume increased, systemic resistance decreased, and pumonary resistance did not change. In the beta adrenergic blockade group, the vascular pressures all increased significantly when CSF pressure was elevated, but cardiac output did not change. Systemic resistance increased and pulmonary resistance decreased. Central blood volume increased in all three groups when CSF pressure was 200 mm Hg. The data suggest that a large and distinct alpha and beta adrenergic stimulus occurred when CSF pressure was increased to 200 mm Hg.

Intrathoracic Cystic Hygroma A Report of Three Cases

Three cases of cystic hygroma in adults are presented. Cystic hygroma is a type of lymphangioma with large dilated cystic lymph spaces which usually occur in the neck or axillae in infants. The mediastinal type of cystic hygroma is rare (less than 1%) and is usually not discovered until adulthood because of its asymptomatic nature and deep location. Roentgen findings are not specific, but features which help differentiate cystic hygroma from other malignant processes include a sharp border and uniform density to the mass, macroscopic cystic lymph spaces, and little lobulation of the surface of the mass. Treatment is early surgical excision.

Pseudolymphoma of the lung in a patient with systemic lupus erythematosus

A 47 year old woman with systemic lupus erythematosus was found to have asymptomatic pulmonary nodules. Histologically they represented benign reactive lymphoreticular hyperplasia compatible with the diagnosis of pseudolymphoma. Immunofluorescence and electron microscopy demonstrated immunoreactants and electron-dense deposits in the alveolar and vascular walls, suggesting that an immune complex mechanism may be involved in this case.

Arrhythmias in Patients with Chronic Obstructive Pulmonary Disease

Cardiac arrhythmias are commonly associated with chronic obstructive lung disease and these arrhythmias can impair arterial blood oxygenation. The etiology of the arrhythmias is multifactorial. The treatment of the arrhythmias is largely the treatment of the deranged physiology and the underlying pulmonary disease. The association of arrhythmias with chronic obstructive lung disease portends a poor prognosis.

Esophageal fistula complicating mediastinal histoplasmosis: Response to amphotericin B

A 41-year-old man was admitted for evaluation of hemoptysis, dysphagia, and pleuritic chest pain associated with a mediastinal mass. Esophagography demonstrated a fistula between the mass and the esophagus. Results of histoplasmosis complement fixation serologic testing suggested an active infection. A methenamine silver stain of a lymph node obtained at mediastinoscopy revealed Histoplasmosis capsulatum. The patient was successfully treated with amphotericin B. This is believed to be the first reported case of an esophageal fistula as a complication of mediastinal histoplasmosis successfully treated with amphotericin B.

Diffusion and flow transfer of theophylline across the blood-brain barrier: Pharmacokinetic analysis

Two possible schemes describing the transfer of theophylline across the blood-brain barrier are investigated. The first, the “diffusion only model,” assumes that the rate of transfer is proportional to the difference in free drug concentration in the serum and cerebrospinal fluid. The second, the “diffusion and flow model,” has the added feature that drug may be transferred from the CSF to the blood by the continuous secretion of CSF into the blood. Comparison of the results of nonlinear regression for the two proposed schemes indicated that the “diffusion and flow” model best describes the transfer process. The analysis indicates that the parameters obtained for the “diffusion and flow” model are physiologically meaningful.

Components of the hemodynamic response to elevated cerebrospinal fluid pressure.

Abstract The cardiovascular effects of elevated cerebrospinal fluid (CSF) pressure were studied in adrenalectomized dogs with and without ganglionic blockade. A significant increase in vascular pressures and cardiac output occurred in those without ganglionic blockade but was absent or markedly blunted in those with ganglionic blockade. This indicated that an intact sympathetic nervous system was required for the pressor response to elevated cerebrospinal fluid pressure but the adrenals were not required. A betaadrenergic effect was noted in dogs with ganglionic blockade and adrenalectomy. The effects of elevated CSF pressure were also studied using a perfused gracilis muscle preparation in 12 animals with beta-adrenergic blockade, with and without adrenalectomy. Animals with intact adrenals and denervated gracilis muscle showed an increase in aortic pressure and gracilis muscle resistance. Adrenalectomized animals with innervated gracilis muscle demonstrated an increase in aortic pressure and gracilis muscle resistance. Elevated CSF pressure with intact adrenals and alpha-adrenergic blockade demonstrated a decrease in aortic pressure but no change in gracilis muscle resistance. The presence of a nonadrenal circulating beta agonist that increases cardiac output and decrease peripheral vascular resistance is indicated by these studies. Also, the Cushing reflex involves an adrenal alpha-adrenergic component affecting skeletal muscle resistance and another alpha-adrenergic component dependent on an intact sympathetic nervous system.

Intermittent positive-pressure breathing: A critical appraisal

There are relatively few valid indications for the use of intermittent positive-pressure breathing (IPPB). It is of limited or no value as prophylaxis of postoperative pulmonary problems (pneumonia, atelectasis) or as a means of delivering aerosol medications or treating stable chronic obstructive pulmonary disease. In these situations, IPPB has few if any advantages over voluntary hyperventilation or deep breathing.

Endobronchial lavage phospholipids and protein in rats protected from oxygen toxicity by hypoxia pretreatment

Abstract Endobronchial lavage phospholipids and proteins were compared in controls, rats exposed to 99 + % oxygen for 52 hr, and rats exposed to 5 days of hypoxia followed by 52 hr of 99 + % oxygen. The rats exposed to 99 + % oxygen had significantly less phospholipids and more protein in their endobronchial washings than the controls. In contrast, the hypoxia-pretreated rats had comparable levels of phospholipids and protein in endobronchial washings compared to controls. This study indicates that phospholipids and proteins in endobronchial lavage provide a metabolic marker for the study of oxygen toxicity.