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Biomedical subjects

R E Brashear

Publications and source records attributed to R E Brashear.

At least 37 records · Page 2Linked to original sources
PubMed1982

Theophylline elimination in the pregnant and fetal rabbit.

Aminophylline and theophylline are commonly used to treat asthma. We studied theophylline pharmacokinetics in the pregnant and nonpregnant rabbit as well as in the intrauterine and extrauterine fetus. The t1/2 was increased (p less than 0.05) and the clearance was decreased (p less than 0.05) in the pregnant compared to the nonpregnant rabbit. The t1/2 of theophylline in the newborn rabbit was 43.5 +/- 12.0 hr, approximately 15 times longer than in the nonpregnant rabbit. Twenty-four hours after a 20 min maternal aminophylline infusion, both the intrauterine fetus and maternal serum theophylline concentrations were very similar. The transplacental transfer from the maternal to fetal circulation occurred in less than 1 hr. The maternal to fetal serum ratios for theophylline were similar after a 5-day maternal aminophylline infusion (ratio 1.22 +/- 0.20) or after a 20 min infusion (ratio 1.24 +/- 0.20). Our findings indicate that the newborn rabbit eliminates theophylline very slowly, and maternal aminophylline or theophylline therapy that would result in high peak serum concentrations in the fetus, particularly just before birth, should be avoided.

Aminophylline↗
PubMed1981

Surgical treatment and course of pulmonary pseudotumor (plasma cell granuloma).

A number of benign clinical conditions of the lung may simulate carcinoma. Pulmonary pseudotumor, which falls into this category, may present as a mass lesion or rarely as an infiltrate. This paper describes six patients with pulmonary pseudotumor, their surgical treatment and, for the first time, a postoperative follow-up ranging from 1 to 10 years. Histories of heavy cigarette smoking were obtained in four. Discrete masses on x-ray films were present in five, and one had localized infiltrates. Lobectomy was performed in two and partial mass resection or removal of tissue for biopsy in four. In this latter group, postoperative x-ray films from 1 to 10 years later showed complete disappearance of the lesions. No subsequent malignant lesion developed, and there was no early or late mortality. This unique experience documents for the first time the natural course of pulmonary pseudotumor. On the basis of this and isolated reports in the literature, pseudotumor must be carefully differentiated from carcinoma. Once diagnosed, as minimal lung resection as possible is indicated.

Adult↗
PubMed1980

Effects of acute plasma for blood exchange in experimental polycythemia.

This study was performed to assess the effects of equal volume plasma-for-blood exchanges in the chronically polycythemic dog. Red blood cells were periodically injected until the hematocrit exceeded 60%. Thereafter, the hemodynamic effects of five plasma-for-blood exchanges (8 ml/kg/exchange) were compared to values obtained during control, maximal polycythemia, and a recovery period. Cardiac output decreased 40% (p less than 0.01) during maximal polycythemia and increased significantly after the first two exchanges. In chronically polycythemic dogs, plasma-for-blood exchanges that decreased the hematocrit to 56-62% reverted selected cardiovascular parameters to or toward control values.

Animals↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1978

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↗
PubMed1977

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↗
PubMed1976

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↗
PubMed1976

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↗
PubMed1976

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↗
PubMed1975

Tetany: quantitative interrelationships between calcium and alkalosis.

Tetany occurs with hypocalcemia and alkalosis or both. The interrelationship of calcium and acid-base balance necessary for inducing tetany, the role of the central nervous system, and the rate of development of hypocalcemia have been investigated. Tetany occurred in less than 50 percent of one group of dogs made alkalotic by hyperventilation or made hypocalcemic by infusion of ethylene glycol-bis(beta-amino ethyl ether) N, N'-tetraacetate. In contrast, hypocalcemia combined with hypocapnic alkalosis always produced tetany. Slowly evolving hypocalcemia was achieved inanother group of dogs by thyroparathyroidectomy, and tetany was induced postoperatively by hypocapnic alkalosis. An identical relationship between serum calcium ion concentration and arterial pH or CO2 tension was found in both groups. Tetany could not be related to the cerebrospinal fluid (CSF) calcium ion content in either group. Hypocalcemia and alkalosis are therefore coparticipants in the development of tetany and are independent of the rate of development of hypocalcemia and of CSF calcium ion concentration. The importance of alkalosis in tetany with hypoparathyroidism is emphasized.

Alkalosis, Respiratory↗