Cholesterol ester hydrolysis by homogenates of whole testis, seminiferous tubules and interstitial cells of mature rats.

The characteristics and localization of a cholesterol ester hydrolase enzyme in homogenates of whole testis and in isolated seminiferous tubules and interstitial cells of mature rats have been investigated. Hydrolysis of cholesteryl [1(-14)C]oleate occurred at an optimum pH of 7.0, was linearly related to time up to 5--6 h of incubation and increased linearly up to 0.25 mg protein/incubation. Hydrolytic activity was inhibited by increasing the incubation temperature from 29 to 41 degrees C and by sonication. Cholesterol ester hydrolase activity/mg protein was three times greater in homogenates of seminiferous tubules than in interstitial cells. Cholesterol ester hydrolase may function to provide precursors for use in seminiferous tubular steroid hormone biosynthesis or germ cell maturation.

Peripheral blood eosinophilia in association with sarcoidosis.

OBJECTIVES: To review retrospectively our experience with peripheral blood eosinophilia (PBE) in sarcoidosis and to analyze histologically lung biopsy specimens for the presence of lung tissue eosinophils. PATIENTS AND METHODS: We reviewed 140 cases of sarcoidosis diagnosed between May 1975 and January 1998. Ninety-five patients (66.3% women; 70.5% African American; mean age, 35.9 years) met the inclusion criteria. Transbronchial biopsy specimens from 82 patients were divided into 4 morphologic compartments: parenchyma, bronchial wall, parenchymal granulomas, and bronchial wall granulomas. Within compartments, up to 10 high-power fields were scored semiquantitatively for eosinophils, from 0 (none) to 4+ (numerous). RESULTS: Thirty-nine patients (41%) had PBE. Four had PBE greater than 10%. The highest eosinophil count (21%) occurred in 1 patient. Sixty-five (79%) of 82 patients had no or few (1+) eosinophils in lung tissue; 17 patients had eosinophils scored as 2+ or higher. There was no correlation between peripheral blood eosinophil count and presence of eosinophils in transbronchial biopsy specimens. Eosinophils were least conspicuous in parenchyma but evenly distributed in bronchial wall and parenchymal and bronchial wall granulomas. CONCLUSIONS: Peripheral blood eosinophilia occurs frequently in sarcoidosis. However, there appears to be no association between peripheral blood eosinophil count and presence of lung tissue eosinophils. Whether eosinophils participate in the pathogenesis of sarcoidosis requires further study.

Disseminated miliary blastomycosis leading to acute respiratory failure in an urban setting.

Disseminated blastomycosis, usually a chronic slowly progressive illness, primarily occurs in individuals with a history of exposure to a rural environmental source. We report a case of disseminated blastomycosis leading to acute respiratory failure in a young man confined to prison in an urban area.

Lung herniation. A cause of chronic chest pain following thoracotomy.

Chronic chest pain is a common complication following thoracotomy, which is generally attributed to intercostal neuritis or neuralgia. Response to medical treatment is poor. We report a case of persistent chest pain following open lung biopsy, which was found to result from lung herniation, a rare, but surgically correctable complication of thoracotomy. Since lung herniation may be easily overlooked, this disorder should be considered more often in the differential diagnosis of persistent postthoracotomy chest pain.

Respiratory muscle rest using nasal BiPAP ventilation in patients with stable severe COPD.

To more systematically evaluate the effect of respiratory muscle rest on indices of ventilatory function, nine outpatients with stable, severe COPD were treated with nasal pressure-support ventilation delivered via a nasal ventilatory support system (BiPAP, Respironics, Inc) for 2 h a day for 5 consecutive days. An additional eight control patients were treated with sham-BiPAP. Maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), maximum voluntary ventilation (MVV), arterial blood gas values, Borg dyspnea score, dyspnea-associated functional impairment scales, and distance walked in 6 min were measured in subjects prior to and following the week-long trial. Nasal BiPAP produced a 66.3 +/- 6 percent reduction in peak integrated diaphragmatic electromyographic (EMG) activity. There were no statistically significant changes in MIP, MEP, MVV, arterial pH, PaCO2, or PaO2 or in objective measures of functional impairment from dyspnea in either group after ventilator or sham treatment. However, nasal BiPAP reduced the Borg category score during resting, spontaneous breathing from 2.0 +/- 0.4 to 0.7 +/- 0.3 (p < 0.01) after 5 days of treatment. In contrast, sham BiPAP-treated patients had no change in their dyspnea score, which was 1.8 +/- 0.4 and 1.3 +/- 0.4 before and after sham treatment, respectively. Nasal BiPAP also increased distance walked in 6 min from 780 +/- 155 to 888 +/- 151 ft (p < 0.01) (23,400 +/- 4,650 to 26,640 +/- 4,530 cm) (p < 0.01), whereas sham-BiPAP had no effect (768 +/- 96 and 762 +/- 106 ft [23,040 +/- 2,880 and 22,860 +/- 3,180 cm]) before and after sham treatment, respectively). In conclusion, these results indicate that nasal pressure-support ventilation, delivered via nasal BiPAP, improves exercise capacity and reduces dyspnea over the short term in selected outpatients with stable severe COPD. Whether such short-term improvement can be sustained merits further study.

Use of a ventilatory support system (BiPAP) for acute respiratory failure in the emergency department.

STUDY OBJECTIVES: Bilevel pressure ventilation has had proven success in the treatment of acute respiratory failure (ARF). The purpose of this study was to identify patient characteristics early in the course of acute illness that can predict the successful use of bilevel pressure ventilation. METHODS: Ventilatory assistance using a ventilatory support system (BiPAP model ST-D; Respironics; Murrysville, PA) was considered a treatment option for stable patients with ARF. The system was titrated to patient comfort. Once stable settings had been achieved for 30 min, a posttrial arterial blood gas (ABG) measurement was obtained. Patient charts were reviewed for pretrial and posttrial ABG levels, along with demographics, APACHE (acute physiology and chronic health evaluation) II score, Glasgow Coma Scale (GCS), and length of stay (LOS) data. RESULTS: Bilevel pressure ventilation trials were performed on 58 patients. In 43 patients (74.1%), the trials were successful. Of the 15 patients (25.9%) in whom the trials were not successful, 13 patients required intubation. The pretrial ABG levels did not predict success, as there were no significant differences between the success and failure groups for pH and PaCO2, respectively: 7.26 vs 7.26 mm Hg and 75.3 vs 72.8 mm Hg. After 30 min, posttrial ABG levels for pH and PaCO2 predicted successful avoidance of intubation: 7.34 vs 7.27 mm Hg (p < 0.002) and 61.9 vs 73.0 mm Hg (p < 0.04), respectively. There were no significant differences between the success and failure groups in age, gender, GCS, or APACHE II. There were differences between the success and failure groups for LOS data (ventilator days, ICU days, and hospital days): 1.8 vs 10.4 days (p < 0.01), 4.2 vs 12.3 days (p < 0.02), and 7.5 vs 15.6 days (p < 0.02), respectively. CONCLUSION: Successful treatment with bilevel pressure ventilation could not be predicted by pretrial data (including pH and PaCO2) obtained in the emergency department; however, a successful outcome could be determined quickly with a 30-min trial. Successful treatment with bilevel pressure ventilation significantly reduced LOS data. CLINICAL IMPLICATIONS: Our inability to predict success based on initial data supports the use of bilevel pressure ventilation trials for all stable patients with ARF. If the patient's condition fails to improve within 30 min, intubation and mechanical ventilation is indicated.

Successful use of nasal BiPAP in three patients previously requiring intubation and mechanical ventilation.

Noninvasive mask ventilation may be used to treat patients with impending respiratory failure. In this case series, three patients with severe chronic obstructive pulmonary disease, who required mechanical ventilation in the past, were successfully treated with nasal bi-level positive airway pressure (BiPAP). All patients tolerated BiPAP well without complications. Therefore, nasal BiPAP may be considered a treatment option for patients with severe COPD who have previously required intubation and mechanical ventilation.

Metabolism of cholesterol-enriched chylomicrons. Catabolism of triglyceride by lipoprotein lipase of perfused heart and adipose tissues.

The chemical and biochemical properties of cholesterol-enriched and cholesterol-poor chylomicrons from rat lymph have been compared. The enriched particles, prepared from cholesterol-containing lipid dispersions, passed into the duodenum, had four to ten times the cholesteryl ester content of the control chylomicrons but had the same content of total "core" (cholesteryl ester + triglyceride) lipid. Both chylomicron species had the same protein composition, the same phospholipid composition, and the same composition of triglyceride fatty acids. The rate of hydrolysis of chylomicron triglyceride for enriched and control particles was determined using both soluble and membrane-supported lipoprotein lipase (LPL) species from heart and adipose tissues. The lipase that was functional in the isolated perfused heart showed no significant difference in initial catabolic rate with cholesterol-enriched and control chylomicrons. The same result was obtained with this isolated LPL species in vitro. The lipase that was functional in isolated perfused epididymal adipose tissue showed a slightly lower catabolic rate with cholesterol-enriched particles (84% of that obtained with control chylomicrons). The same result was obtained with isolated adipose tissue LPL. It is concluded that cholesteryl ester content of chylomicrons under these conditions neither affects their protein composition nor has a major effect on their rate of reaction with lipoprotein lipase.

Survey of physicians' attitudes about risks and benefits of chest computed tomography.

To investigate physicians' use of computed tomography (CT) of the chest and their attitudes regarding the risks and benefits of chest CT, we conducted a nationwide survey of 1,000 board certified physicians from several specialties of medicine, using a self-administered mail questionnaire. Three hundred thirteen surveys were completed. Overall, CT ordering practices varied with specialty. While the majority of physicians believed that CT provided new information (64%) and influenced patient management (62%), fewer physicians (30%) perceived that CT improved patient outcome. More than 90% of physicians either did not know or significantly underestimated the degree of radiation associated with CT (equivalent to 100 posteroanterior chest radiographs). We conclude that, given the paucity of prospective controlled trials establishing clear indications for the use of chest CT, physicians across all specialties should give careful consideration to the anticipated benefits and potential risks of chest CT before using this test.

Recurrent acute scleroderma renal crisis complicated by thrombotic thrombocytopenic purpura.

Acute renal crisis as an early manifestation of scleroderma is underemphasized, and its recurrence after initial successful therapy is rare. We describe a 32-year-old woman who presented with scleroderma renal crisis. A second episode of apparent renal crisis, however, was complicated by thrombotic thrombocytopenic purpura, which led to pancreatitis, a large cerebral infarction, and fatal outcome despite intensive therapy. This case illustrates the complexity and severity of diffuse systemic sclerosis presenting with multiple, major organ complications.

Concentrations of free and esterified cholesterol in the testes of maturing rabbits.

Levels of cholesterol and cholesterol esters were established in the testes of maturing New Zealand white rabbits. Free cholesterol levels remained relatively constant throughout pre- and post-pubertal development. The total cholesterol, cholesterol esters and percentage esterified cholesterol values were highest during the prepubertal period and decreased steadily thereafter, reaching their lowest after 90 days of age. Correlations of these findings with hormonal and morphological changes during testicular development are discussed.