Comparison of students' encounters with patients in university and community hospitals.
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Chicago↗
Biomedical subjects
R C Bone
Publications and source records attributed to R C Bone.
Prospective payment. A procrustean paradigm.
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Diagnosis-Related Groups↗
Therapeutic implications of acute lung injury.
Although there are no specific therapies for septic shock or acute lung injury that have proven efficacy in humans, a growing understanding of mechanisms of tissue injury has suggested interventions that may prevent or treat this injury. These therapies range from immunization against the glycopolysaccharide core of endotoxin to cyclooxygenase inhibitors to specific oxygen radical scavengers. Each of these treatments is effective in ameliorating at least one of the pathophysiologic manifestations of acute lung injury, although the effect of these agents in the prevention of the sequelae of fibrosis is unknown. Interaction between several factors and mediators is likely necessary for the development of acute lung injury. It is hoped that with additional knowledge regarding mechanisms of injury gained through basic science and clinical research, we can apply definitive therapy that may salvage patients who now die with sepsis and acute lung injury.
Blood Platelets↗
A culprit in health care costs.
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Health Resources↗
Quantitative deposition of ultrafine stable particles in the human respiratory tract.
Theoretical models of particle deposition in the respiratory tract predict high fractional deposition for particles of less than 0.1 micron, but there are few confirming experimental data for those predictions. We have measured the deposition fraction of a nonhygroscopic aerosol in the human respiratory tract. The aerosol had a count mean diameter of 0.044 micron SD of 1.93, as measured with an electrical aerosol analyzer, and was produced from a 0.01% solution of bis(2-ethylhexyl) sebacate using a condensation generator. Subjects inhaled the aerosol using a controlled respiratory pattern of 1 liter tidal volume, 12/min. Deposition was calculated as the difference in concentration between inhaled and exhaled aerosol of five size fractions corrected for system deposition and dead-space constants. Three deposition studies were done on each of five normal male volunteers. Means (+/- SE) for the five size fractions were 0.024 micron, 0.71 +/- 0.06; 0.043 micron, 0.62 +/- 0.06; 0.075 micron, 0.53 +/- 0.05; 0.13 micron, 0.44 +/- 0.04; and 0.24 micron, 0.37 +/- 0.06. These data demonstrate that deposition of inhaled particles in the 0.024- to 0.24-micron size range is high and increases with decreasing size. These observations agree with and validate predictions of mathematical models.
Adult↗
Immunoglobulin G-induced single ionic channels in human alveolar macrophage membranes.
While it is well known that the engagement of IgG Fc receptors on the macrophage surface triggers a number of cellular responses, including particle ingestion, secretion, and respiratory burst activity, the mechanism of signal transmission following ligand binding remains poorly understood. To acquire more data in this area, we studied the electrical properties of the macrophage membrane and its response to oligomeric immunoglobulin G (IgG) using the patch-clamp technique on human alveolar macrophages that were obtained by bronchoalveolar lavage and maintained in short-term tissue culture. The results showed that cell resting potentials, as determined from whole-cell tight seal recordings, increased from -15 mV on the day of plating to -56 mV after the first day in culture and remained stable at this hyperpolarized level. Macrophages revealed an input resistance of 3.3 G omega, independent of age in culture. Extracellular application of heat-aggregated human IgG to cells voltage-clamped at -70 mV resulted in peak inward currents of approximately 470 pA. We identified an IgG-dependent, nonselective channel in both cell-attached and isolated membrane patches, with a unitary conductance of approximately 350 pS and a predominant subconductance level of 235 pS in symmetrical NaCl solutions. Single channel open times were observed to be in the range of seconds and, in addition, were dependent upon membrane voltage. Channel opening involved transitions between a number of kinetic states and subconductance levels. Channel events recorded in cell-attached patches showed characteristic exponential relaxations, which implied a variation in membrane potential as a result of a single ion channel opening. These data suggest that the IgG-dependent nonselective cation channel that we have characterized may provide the link between Fc receptor engagement and subsequent cellular activation.
Adult↗
Sjogren's syndrome: a persistent clinical problem.
One hundred sixty patients with Sjogren's syndrome have been evaluated and managed at Scripps Clinic. Objective diagnosis has relied heavily on rose-bengal vital staining and corneal slit lamp examination to establish the presence of KCS and lip biopsy. The role of the head and neck surgeon in evaluating the patient with "dry mouth" is discussed. Usually Sjogren's syndrome is managed nonsurgically, but problems of abscess, recurrent infection, disfigurement, and malignant transformation may result in the need for total parotidectomy with nerve preservation. Radiation for Sjogren's syndrome is rarely, if ever, indicated. The etiology of Sjogren's syndrome may be closely tied to the homogeneous genetic background of its patients and the presence of a chronic immunogenic stimulus well recognized in the secondary form but less clear in the primary.
Diagnosis, Differential↗
Extraglandular Warthin's tumors.
Warthin's tumor or papillary cystadenoma lymphomatosum (PCL) represents a clinically significant entity, not because of pernicious behavior, but because its cytohistological characteristics tell us much about the development and morphology of the parotid region. Three cases operated on in which PCL developed in an extraglandular location from the parotid, formed the basis for a series of observations on what is known about: 1. etiology of PCL; 2. the nature of the lymphocytic components; 3. the relatively high incidence of bilateral and multiple occurrence, as well as male predominance. These studies employed immunohistological techniques using a series of monoclonal antibodies.
Adenolymphoma↗
Technology under Medicare diagnosis-related groups prospective payment. Implications for medical intensive care.
Medicare prospective payment by diagnosis-related groups (DRGs) has intensified the debate over the use and costs of medical technology. In this study, we examine the financial impact of DRG payment for medicare patients receiving medical intensive care. During a one-year period, payment for 446 Medicare patients receiving medical intensive care at a large teaching hospital was calculated to be +4.7 million below costs, representing an average loss per discharge of +10,567. Patients stayed an average of 21.6 days including an average of 5.0 days in the medical intensive-care unit--23 percent of the total stay. Twenty-eight percent of the MICU patients died during hospitalization. For this group, the average payment per discharge was projected to be +21,651 below the average per discharge cost. We conclude that the results send strong financial messages to hospitals providing medical intensive care to severely ill, elderly patients. Further exploration and research must occur to ensure hospital responses will be consistent with public policy expectations.
Costs and Cost Analysis↗
Intensive care monitoring in a cost-conscious age.
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Chicago↗
Critical care medicine. The past and changes in the future.
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Critical Care↗
Research on ibuprofen for sepsis and respiratory failure.
According to an experimental study in 26 dogs, ibuprofen reversed the hypotension, increased the cardiac index, prevented the acidosis associated with endotoxic shock, and apparently improved survival. In animals given endotoxin followed by ibuprofen, an initial decrease in systemic blood pressure subsequently recovered to 150.2 +/- 4.1 mm Hg in 120 minutes (p less than 0.001). Cardiac index increased in ibuprofen-treated animals (2.3 +/- 0.28 1/m2 per minute), compared with animals given endotoxin alone (1.0 +/- 0.09 1/m2 per minute) by termination of the experiment. In addition, although arterial pH decreased to 7.18 +/- 0.03 by 120 minutes in animals given only endotoxin, final pH was 7.36 +/- 0.01 in the ibuprofen-treated group.
Animals↗
Primary Sjogren syndrome: clinical and immunopathologic features.
Primary Sjogren syndrome is an autoimmune condition in which dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) result from lymphocytic infiltration of lacrimal and salivary glands. Clinical and laboratory features of 60 primary Sjogren syndrome patients seen at our clinic during the past three years are presented. These patients illustrate the wide spectrum of extraglandular features that may occur as a result of lymphoid infiltration of lung, kidney, skin, stomach, liver, and muscle. They further emphasize the difficulty in classifying a patient as primary or secondary Sjogren syndrome (ie, sicca symptoms associated with systemic lupus erythematosus, rheumatoid arthritis, or scleroderma), particularly early in the disease course. As an initial step in understanding the pathogenesis, the lymphocytes that infiltrate the salivary glands and lymph nodes were characterized by using monoclonal antibodies that recognize distinct lymphocyte subsets and by using in vitro functional assays. These studies have demonstrated that affected tissues have infiltrates of T cells with helper/inducer activity and with a high frequency of "activation antigens." The immunohistologic techniques are useful in differentiating "benign" and "pseudolymphoma" lesions (both due predominantly to T cells) from non-Hodgkin lymphoma (usually due to B-cell infiltrates). Although there is no "cure" for primary Sjogren syndrome patient's symptoms may be significantly improved by measures aimed at prevention of ocular and dental complications and by the recognition of extraglandular features that may be amenable to specific treatment.
Adolescent↗
Protection of myocardial function during endotoxin shock by ibuprofen.
We have concluded that Ibuprofen, a cyclooxygenase inhibitor with high specificity for the preferential blockage of thromboxane synthetase, significantly improves arterial blood pressure, cardiac index, and arterial pH during endotoxin shock in dogs (J. Clin. Invest. 70:536, 1982). This study was undertaken to determine whether Ibuprofen (25 mg/kg i.v.) administered 20 min prior to endotoxin (2 mg/kg i.v.) is able to overcome the depressed ability of cardiac microsomes to actively sequester calcium after 2 hrs of endotoxin shock. Results indicate that microsomes isolated from hearts of animals pretreated with Ibuprofen and then given endotoxin are able to sequester calcium at rates similar to microsomes isolated from control hearts. Microsomes isolated from hearts of animals in endotoxin shock without Ibuprofen show the anticipated depression of calcium sequestering ability. The improved ability of microsomes from the hearts of animals pretreated with Ibuprofen to sequester calcium is the result of normal Ca+2-Mg+2 ATPase activity in the microsomal membrane. We conclude that Ibuprofen protects against the detrimental hemodynamic derangements of endotoxin induced shock in the dog, and thereby also improves cardiac subcellular calcium transport; the factor regulating contractility. Ibuprofen may warrant evaluation as a protective agent to be used prophylactically in high risk cases of endotoxemia.
Animals↗
Concentration and particle size distribution in smoke from marijuana cigarettes with different delta 9-tetrahydrocannabinol content.
Particle size and mass concentration are important determinants of site and quantity of respiratory tract deposition of aerosols. Particle concentrations and size distributions of smoke from marijuana cigarettes with different concentrations (as measured in the marijuana leaf) of delta 9-tetrahydrocannabinol (delta 9-THC) were measured using a single particle aerodynamic relaxation time (SPART) analyzer. The SPART analyzer measures aerodynamic diameter of single suspended particles at a rate of 3000/min. Cigarettes were smoked using a 35-cc, 2-sec puffing device attached to a diluter; dilution and analysis were completed within 4 sec of puff generation. The size distribution of smoke from all marijuana cigarettes was similar to that for tobacco cigarettes, ranging from 0.35 to 0.43 micron (count median aerodynamic diameter). The particle number and mass concentration increased as delta 9-THC concentration increased, being, respectively, 2.2- and 3.8-fold higher in the marijuana cigarette leaf with highest delta 9-THC concentration compared to the placebo marijuana cigarette. These data indicate the need for quantitative comparisons of other potentially toxic constituents in marijuana cigarettes of different delta 9-THC concentrations.
Cannabis↗
Histamine and slow reacting substance in acid-induced pneumonitis.
Acid pneumonitis was produced in 18 dogs by the tracheal instillation of 3 ml/kg 0.1 N hydrochloric acid. Arterial and mixed venous oxygen tension, static compliance and pulmonary capillary wedge pressure were measured during a 2-hour observation period. Plasma histamine (measured by the enzymatic isotopic assay) increased from 1.7 +/- 0.2 ng/ml (mean +/- SE) before acid injury to 13.5 +/- 1.9 ng/ml after injury (p less than 0.05). In one group of 7 control dogs, 3 ml/kg of normal saline produced no increase in plasma histamine. Pulmonary edema secretions from acid injured animals had a histamine level of 30.3 +/- 3.8 ng/ml and slow reacting substance was detected in 7 of 11 animals. The slow reacting substance was an antihistamine-resistant, ethanol extractable substance that contracted guinea pig ileum. Lung weight-body weight ratio PaO2, and static compliance were different with acid pneumonitis compared to controls. Total protein was not different in the tracheal secretions compared to plasma. We conclude that histamine and slow reacting substance are released in this animal model of acid pneumonitis and may be important in the pathogenesis of the lung injury.
Animals↗
Potentiation of Cd-induced pulmonary injury in alpha 1-antitrypsin suppressed rats.
The interrelationship of alpha 1-antitrypsin (alpha 1-AT) or serum trypsin inhibitor capacity (TIC) level and cadmium exposure in the induction of pulmonary lesions was investigated. Sprague-Dawley rats were exposed to CdCl2, galactosamine, or galactosamine + CdCl2 for 24 hr. Biochemical study indicated a 20% reduction of serum TIC in animals exposed to galactosamine. A marked, 50%, reduction of serum TIC was induced in animals exposed to galactosamine + CdCl2. Histopathological study revealed no major morphological lesions in lungs of animals exposed to either CdCl2 or galactosamine. However, extensive lesions, including polymorphonuclear leukocyte (PMN) infiltration, distortion and distention of the alveolar spaces, and massive hemorrhages were observed in the lungs of animals exposed to galactosamine + CdCl2. It is believed that cadmium can induce rapid lesions in the pulmonary tissues when the alpha 1-AT is significantly suppressed. The present investigation has provided direct evidence on the importance and interrelationship of cadmium and alpha 1-AT in pulmonary lesion development.
Animals↗
Pulmonary emboli with respiratory failure.
The diagnosis of pulmonary emboli may be difficult or delayed because of the clinical similarity to other acute medical events or from superimposed embolic phenomena in patients with pre-existing pulmonary and cardiovascular disease. The clinical presentation, diagnosis, and medical and surgical intervention in patients with massive emboli are discussed.
Adult↗