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Biomedical subjects

R E Brashear

Publications and source records attributed to R E Brashear.

At least 19 recordsLinked to original sources

Effect of alteration of cerebrospinal fluid bulk flow on nicotine cerebrospinal fluid exit transfer kinetics.

This study was undertaken to determine if a compound which alters the bulk flow of cerebrospinal fluid (CSF) alters the elimination kinetics of a compound in the CSF. Acetazolamide was chosen as the CSF bulk flow-altering agent. It produces a relatively large effect on the flow process, affecting both choroidal and extrachoroidal CSF production, and has been shown to affect CSF flow following iv administration. The compound monitored was nicotine. Acetazolamide was administered orally for one week before and intravenously during the experiment. Nicotine was administered by a bolus injection directly into the CSF via the cisterna magna. The results indicate that the introduction of acetazolamide into the general circulation increases the rate of removal of nicotine from the CSF. Subjects receiving acetazolamide had elevated CSF pressures. The increase in CSF pressure associated with the administration of acetazolamide suggests pressure as a possible factor in the observed increase in the rate of removal of nicotine.

Acetazolamide

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.

Adult

Cystic fibrosis. An adult perspective.

We treated a patient with an unusual case of cystic fibrosis in whom the diagnosis was not made until age 42 years, the predominant clinical manifestation was recurrent pancreatitis, and the chest roentgenogram and results of pulmonary function tests were normal between bouts of pneumonia. As cystic fibrosis may simulate more benign conditions often seen in adults, the diagnosis must be suspected and confirmed for optimal management. Internists must play an increasingly important role in the diagnosis and management of this disease.

Adult

Activated charcoal in theophylline intoxication.

To test the hypothesis that orally administered activated charcoal alters the elimination kinetics of intravenously administered theophylline, six dogs were twice infused with theophylline, 28 mg/kg, over 20 minutes 1 week apart. In a random sequence separated by 1 week, they received either activated charcoal, 30 gm in a water suspension or water only through a nasogastric tube every 2 hours after theophylline infusion, for a total of four doses. The time needed for plasma levels to fall below 20 mg/L was approximately 5 hours regardless of charcoal treatment. However, activated charcoal decreased theophylline halflife from 4.02 to 2.76 hours and volume of distribution from 0.72 to 0.61 L/kg. We conclude that although activated charcoal hastened the elimination of theophylline in dogs, the usefulness of orally administered activated charcoal in the treatment of theophylline overdose may be limited by the inability to shorten the time during which plasma levels are toxic.

Administration, Oral

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.

Complement C3

Relationship between arterial and venous bicarbonate values.

We determined the clinical efficacy of using the venous CO2 value, as obtained with routine "electrolytes", in acid-base management. Venipuncture samples for venous CO2 content and chloride concentrations were obtained in 336 patients with arterial blood pH, PaO2, PaCO2, and oxygen saturation determinations. The linear correlation between actual calculated arterial HCO3- and the measured venous CO2 was significant (P less than .001). Using venous CO2, chloride, and arterial pH values, we present various prediction equations for estimating arterial HCO3-. We determined the effects of time delay, exposure to air, and acute changes in arterial blood pH and PaCO2 on venous CO2 levels. Venous CO2 determinations should not be substituted for the arterial HCO3 value in the Henderson-Hasselbalch equation to calculate arterial blood pH or PaCO2. Clinically, the venous CO2 value has little direct use, but when venous CO2 content is abnormal, it should alert the clinician to the need for obtaining arterial blood gas and pH values.

Acid-Base Imbalance

A state-wide survey of hospital policy and practice concerning cigarette sales.

This study was conducted to determine the current practices and problems with regard to the sale of cigarettes in the approved hospitals of Indiana. A questionnaire was sent to all approved hospitals within the state asking each hospital administrator to respond to specific questions concerning cigarette sales policy and practice. After an initial waiting period, a follow-up letter was sent to each nonresponder. Finally, a response rate of 99 per cent was achieved. It was found that approximately 58 per cent of respondents sold cigarettes, with the majority selling cigarettes both over the counter and through vending machines. However, among the 42 per cent of the sample not selling cigarettes, the vast majority (82 per cent) indicated that no problems were encountered with their no-sales policy and practice. On the basis of both a review of literature pertaining to the potential dangers of ambient cigarette smoke and the findings of this study, the writers concluded that a no-cigarette-sales policy in hospitals is reasonable, feasible, and desirable.

Hospital Administration

Protective effect of hypoxia on oxygen toxicity: possible mechanisms.

Previous studies demonstrated a protective effect of hypoxia on subsequent death breathing oxygen. Four groups of rats were exposed to air for 120 hours plus 99% O2 for 52 hours (A + O2); 120 hours of hypoxia plus 52 hours 99% O2 (H + O2); 172 hours of only air (A); and 120 hours of only hypoxia (H). Rats were sacrificed and lung lavage protein (gm/ 100 ml) was 0.57 +/-0.18 in A + O2 and 0.26 +/- 0.12 in H + O2. Hematocrits were increased at sacrifice. Rats with induced hematocrits of 61% did not have a protective effect breathing oxygen. Mean total phospholipid in lung lavage was: A + O2 O.94; H + O2 1.10; A 1.08; and H 1.76 (micronM/ml). Phosphatidyl choline (lecithin) was: A + O2 0.49; H + O2 0.61; A 0.59; and H 1.15 micronM/ml. Differences among the groups were significant for total phospholipids and phosphatidyl choline except between air (A) and hypoxia + O2 (H + O2). Palmitic acid was decreased in A + O2 compared to the other groups. Oxygen breathing results in decreased total phospholipids and phosphatidyl choline in lung lavage. Pretreatment with hypoxia and subsequent oxygen breathing results in amounts similar to rats breathing air only.

Animals

Lymphomatoid granulomatosis: A clinicopathologic study of four cases.

Four cases of lymphomatoid granulomatosis were studied. One case, previously reported, has had a prolonged remission of 8 years' duration. In one case, the course was rapid and progressive, and the patient died 2 months after the onset of the disease. In two other patients, the disease appears to be arrested effectively, both clinically and radiographically, by administration of corticosteroids. In the fatal case, postmortem examination revealed a typical angiocentric and destructive polymorphous lymphoreticular infiltrate in the lungs, kidneys, and adrenal glands. The diagnosis was made on specimens obtained from three patients by open thoracotomy. An adequate specimen is mandatory for diagnosis and thoractomy is indicated. To be considered in the differential diagnosis are Wegener's granulomatosis, the limited form of Wegener's granulomatosis, lymphoma, allergic granulomatosis, lymphocytic interstitial pneumonia, plasma cell granuloma, and infectious granuloma.

Adult

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.

Aerosols

Chronic pulmonary histoplasmosis with declining complement fixation titers and persistence of positive sputum culture. A case report.

A patient with culturally proved chronic pulmonary histoplasmosis was treated with amphotericin B. Complement fixation titers decreased but sputum cultures remained positive for Histoplasma capsulatum 5 months after original therapy. Lobectomy and a subsequent course of amphotericin B were necessary. Exceeding the minimal inhibitory concentrations of amphotericin B did not eradicate the organism and declining complement fixation titers failed to have prognostic significance.

Amphotericin B