The timing, position and mechanism(s) for determining type II cytodifferentiation during mammalian lung development are not known. To approach this problem, we have cultured Theiler stage 16 embryonic B10.A strain mouse lung primordia (12-days gestation, E12) in serumless, chemically defined medium in the presence or absence of dexamethasone (DEX) for periods up to 27 days in vitro. Morphogenesis and cytodifferentiation were evaluated by light and transmission electron microscopy and immunochemical techniques. Pulmonary surfactant-associated apoproteins (PSAP) were initially expressed by type II cells at 16.5-day gestation in vivo. DEX-supplementation to the culture medium resulted in the accelerated expression of PSAP; the apoprotein isoforms (A1, A2, and A3) produced in vitro were comparable to those synthesized during fetal and postnatal in vivo development by high resolution, two-dimensional gel electrophoresis coupled with immunoblot staining. Cultures without DEX produced PSAP A2 and A3 isoforms, but did not produce A1 (26-31 kDa, pI 5.2-5.3). DEX-treated cultures produced more lamellar bodies within type II cells than non-treated controls. The results demonstrate that long-term cultures of embryonic lung primordia express morphogenesis, cytodifferentiation and the synthesis and secretion of PSAP in the absence of exogenous hormones or growth factors. The data set further supports the hypothesis that morphogenesis and type II cytodifferentiation are regulated by autocrine and paracrine factors intrinsic to the embryonic lung developmental program and independent of exogenous hormone controls.

Adrenal Cortex Hormones↗

PubMed1988

Hyperthermia in combination with definitive radiation therapy: results of a Phase I/II RTOG Study.

Between August 1981 and April 1986, 133 patients with superficial malignant tumors not previously treated with radiotherapy were entered on a Phase I/II RTOG study evaluating hyperthermia plus definitive radiotherapy. Eligible patients included those with superficial epithelial or mesenchymal tumors less than 4 cm in depth. Protocol radiotherapy specified a tumor dose of 60 Gy delivered in 1.8-2.0 Gy fractions 5 times/week with a boost of 5-10 Gy through reduced portals to residual tumor. Protocol hyperthermia, delivered twice weekly, was to start within 15 minutes following irradiation and to consist of 60 minutes of heat to a tumor temperature of 43 degrees C. Sixteen patients were excluded. Of the 117 eligible patients, the treated lesions had site/histologies which were 35% head & neck/squamous, 46% breast/adenocarcinoma, and 19% other site/histologies. Lesions were 3 cm or larger for 77% of patients. Of the 41 patients with head & neck/squamous lesions, skin or subcutaneous necrosis occurred within 6 months for 2% of the patients; 12% experienced thermal blisters. Fourteen patients were followed for 6 months or more following start of treatment; none of these experienced late toxicities more severe than telangiectasis. Complete responses were observed in 51% of these patients. Of the 54 patients with breast/adenocarcinoma lesions, skin or subcutaneous necrosis occurred within 6 months for 13% of the patients; 17% experienced thermal blisters. Thirty-seven patients were followed for 6 months or more following start of treatment; complications observed during this period included 13% with ulceration and one case of skin necrosis. Complete responses were observed in 85% of these patients. Local control was maintained at nearly this level for at least 2 years. Logistic regression analyses showed site/histology, greatest tumor diameter and average tumor temperature to be significantly related to response. Based on these promising findings, the RTOG has instituted a randomized Phase III study evaluating radiation therapy with or without hyperthermia in this patient population.

Adenocarcinoma↗

PubMed1988

Impact of acute reduction in chronically elevated left atrial pressure on sodium and water excretion.

To test the hypothesis that a reduction in chronically elevated left atrial pressure would decrease sodium and water excretion in humans, we studied 61 carefully selected patients who underwent cardiac surgery for valvular or coronary artery disease or both. The immediate postoperative decrease in left atrial pressure (from 16.7 +/- 1.0 to 9.4 +/- 0.4 mm Hg; p less than 0.001) was inversely correlated with postoperative urine output (r = -0.69; p less than 0.001) and sodium excretion (r = -0.51; p less than 0.005). There was no significant relationship between postoperative urine output or sodium excretion and other hemodynamic or nonhemodynamic variables. A significant postoperative decrease in plasma atrial natriuretic factor (from 150 +/- 22 to 65 +/- 14 pg/ml; p less than 0.01) and increase in plasma renin activity (from 2.5 +/- 0.6 to 8.7 +/- 3.2; p less than 0.05) occurred in patients with a 7 mm Hg or greater postoperative decrease in left atrial pressure. Thus, an acute reduction in left atrial pressure results in significant reductions in urine output and sodium excretion, the magnitude of which are related to the degree of reduction in left atrial pressure.

Anuria↗

PubMed1988

Scalp-recorded P300 activity in patients following unilateral temporal lobectomy.

The bilateral distribution and overall amplitude of the P300 component of the event-related brain potential (ERP) was studied in epileptic patients in whom the amygdala, hippocampal, and anterior temporal lobe areas of the brain had been resected unilaterally. Previous reports have suggested that a neural generator of the P300 elicited in the commonly used target detection ('Oddball') paradigm lies in these medial temporal areas. In an Oddball paradigm, there was no evidence of any left-right hemisphere asymmetry in the scalp distribution of the P300 that varied as a function of the side of surgery in either the left or right temporal lobectomy patients. Moreover, there were no statistically significant differences in overall P300 amplitude or latency between the patients and controls. These data do not support the hypothesis that the primary generator of the scalp-recorded P300 in the Oddball paradigm lies in the hippocampus and amygdala.

Electrophysiology↗

PubMed1988

Alcohol protects against cholesterol gallstone formation.

Epidemiologic studies have suggested that alcohol intake may protect against cholelithiasis. Gallstone formation was studied in 20 prairie dogs fed a 0.4% cholesterol-supplemented liquid diet. In ten animals, ethanol provided 35% of total calories. In ten pair-fed controls, ethanol was replaced with isocaloric maltose. After 3 months the gallbladders were inspected for gallstones, and gallbladder bile was analyzed. Cholesterol macroaggregates were present in all controls and pigment concretions were noted in five. No stones were observed in ethanol-fed animals. Bile in the ethanol group contained less cholesterol than the controls (5.60 +/- 0.71 vs. 9.16 +/- 0.61 mmol/L, p less than 0.05) while phospholipids, total bile acids, and bilirubin were unchanged. The resulting cholesterol saturation index was reduced in the ethanol group (0.81 vs. 1.22, p less than 0.05). The ratios of trihydroxy to dihydroxy bile acids were also different (2.07 +/- 0.25 in ETOH vs. 3.29 in controls, p less than 0.05). The bile calcium concentration was higher in control animals presumably secondary to the use of complex sugars (5.36 +/- 0.37 vs. 3.77 +/- 0.32 mmol/L, p less than 0.05). These results confirm that ethanol inhibits cholesterol gallstone formation. They further suggest that this effect is dependent on reductions of biliary cholesterol and selective changes in bile acid concentrations.

Animals↗

PubMed1988

Toward a functional categorization of slow waves.

Explore the source record for details and available documents.

Adolescent↗

PubMed1988

Methanogenic bacteria from human dental plaque.

Samples of human dental plaque were examined for the presence of methanogenic bacteria. Of 54 samples from 36 patients, 20 yielded H2/CO2-using methanogenic enrichment cultures. All methanogen-positive samples were from patients with some degree of periodontal disease. The predominant populations in the enrichments had morphologies characteristic of Methanobrevibacter spp. In six enrichments derived from three patients, the common methanogen was antigenically similar to Methanobrevibacter smithii. The same was true for the three methanogenic isolates obtained in axenic culture from a fourth patient. The six enrichments and two of the three isolates were antigenically closer to strain ALI than to PS. Two of the enrichments also had subpopulations with weak antigenic similarity to Methanosphaera stadtmanae. The data indicate that methanogens in the oral cavity of humans are antigenically close to those found in the intestinal tract.

Antigens, Bacterial↗

PubMed1988

Airway obstruction in sarcoidosis. A study of 123 nonsmoking black American patients with sarcoidosis.

Airway obstruction in sarcoidosis is infrequent; however, its exact incidence is not known. The extent and severity of the functional impairment are governed by genetic, racial and environmental factors. In order to test the validity of this assumption we studied 123 black American, nonsmoking patients. Airway obstruction was present in 78 (63 percent) of the patients, considerably higher than the white European and American, and the Japanese patients.

Adolescent↗

PubMed1988

Financial modeling: creating a plan for the future.

In response to decreasing utilization and increasing competition, hospitals are looking for new business opportunities to strengthen their present financial position. But they need a method to evaluate potential new ventures. Using a financial forecasting model, Metropolitan Medical Center was able to effectively evaluate new business opportunities. And by incorporating assumptions specific to an institution into the model, any institution can use this model as a guide for developing an analytical tool for making future business decisions.

Accounts Payable and Receivable↗

PubMed1988