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Biomedical subjects

J P Szidon

Publications and source records attributed to J P Szidon.

At least 19 recordsLinked to original sources
PubMed1998

Lung volume reduction surgery: an analysis of hospital costs.

OBJECTIVE: Lung volume reduction surgery (LVRS) represents a potential breakthrough in the management of advanced emphysema, although questions remain about clinical and economic implications of widespread application of LVRS. In this report, we describe hospital costs, excluding physicians' fees, for LVRS. DESIGN: Hospital charges were obtained from billing records and converted to costs by applying multiple cost-to-charge ratios. SETTING: A large, urban academic medical center. PATIENTS: Fifty-two consecutive patients who received bilateral LVRS through a median sternotomy between April 1995 and August 1996. RESULTS: Median hospital stay was 10 days (mean= 14.8+/-12.8 days; range=3 to 48 days), including 2 days (mean=6+/-9.2 days; range=1 to 35 days) in the ICU. One hospital death occurred. Hospital costs per case ranged from $11,712 to $121,829, with mean costs of $30,976 and median costs of $19,771. Costs were related significantly to duration of ICU stay and length of hospitalization. Patients who accrued the highest costs were significantly older than the remainder of the sample (69.3 years vs 62.4 years). CONCLUSIONS: Hospital costs of LVRS vary significantly but are related directly to hospital stay. Identification of factors associated with prolonged stays can be used in assessing benefits and risks of LVRS against utilization of health-care dollars.

Academic Medical Centers↗
PubMed1995

Physiological outcomes of aerobic exercise training in hemiparetic stroke patients.

BACKGROUND AND PURPOSE: In hemiparetic individuals, low endurance to exercise may compound the increased energy cost of movement and contribute to poor rehabilitation outcomes. The purpose of this investigation was to describe how hemiparetic stroke patients responded to intense exercise and aerobic training. METHODS: Forty-two subjects were randomly assigned to an exercise training group or to a control group. Treatments were given three times per week for 10 weeks in similar laboratory settings. Baseline and posttest measurements were made of maximal oxygen consumption, heart rate, workload, exercise time, resting and submaximal blood pressures, and sensorimotor function. RESULTS: Only experimental subjects showed significant improvement in maximal oxygen consumption, workload, and exercise time. Improvement in sensorimotor function was significantly related to the improvement in aerobic capacity. After treatment, experimental subjects showed significantly lower systolic blood pressure at submaximal workloads during the graded exercise test. CONCLUSIONS: We conclude that hemiparetic stroke patients may improve their aerobic capacity and submaximal exercise systolic blood pressure response with training. Sensorimotor improvement is related to the improvement in aerobic capacity.

Adult↗
PubMed1992

Evaluation of pulmonary complications after bone marrow transplantation: the role of pretransplant pulmonary function tests.

To determine whether an association exists between abnormal pulmonary function tests (PFT) before bone marrow transplantation (BMT) and the rate of pulmonary complications after BMT, we retrospectively reviewed all transplants performed in our center between March 1984 and December 1990. A total of 163 patients, 15 years of age and older, with a hematologic malignancy or a solid tumor were treated with intensive therapy and autologous (118) or allogeneic (55) BMT. Sixty patients (37%) developed a pulmonary complication which contributed to patient death in 29 transplants (18%). Patients with pulmonary metastases, prior thoracotomy, or prior radiation to the chest had a higher frequency of abnormal PFT. By univariate analysis, patients with abnormal FVC, FEV1, or TLC before BMT had a significantly increased rate of pulmonary complications (p < 0.005). By multivariate analysis, the rate of pulmonary complications was significantly associated (p = 0.004) with abnormal FEV1 only: in the first 2 months after transplantation the rate was 65% in patients with FEV1 < 70% in contrast to 34% in patients with FEV1 > or = 70% (risk ratio = 1.9). There was no association, however, between abnormal pretransplant PFT and fatal pulmonary complications. We conclude that patients with pretransplant ventilatory defects have a higher risk of pulmonary complications after BMT, but the incidence of fatal complications was not significantly increased, although we cannot exclude a diminished study power due to the sample size. We believe that patients with abnormal PFT should not be excluded from transplantation if the anticipated anti-tumor effect is estimated to be substantial, but additional preventive measures may be necessary.

Adolescent↗
PubMed1989

Hepatic dysfunction in the adult respiratory distress syndrome.

Multiple organ system failure is a major cause of mortality in the adult respiratory distress syndrome (ARDS). We serially evaluated parameters of multiple organ function in 24 patients during the first week after the diagnosis of ARDS and related them to outcome. The adult respiratory distress syndrome was associated with sepsis (n = 16), postoperation (n = 7), and trauma (n = 1). Fourteen of the 24 patients (58 percent) died. Although there were no significant differences in the indices of pulmonary or renal dysfunction between survivors and nonsurvivors, evidence of hepatic dysfunction was different in the two groups. On the day we identified ARDS, serum bilirubin was 1.2 mg/dl +/- 0.9 mg/dl in patients who survived, and was 2.3 mg/dl +/- 2.8 mg/dl (chi +/- SD) in those who died. Initial serum glutamic oxalacetic transaminase (SGOT) and alkaline phosphatase levels were lower in survivors than in those who died (71 +/- 44 IU/L vs 399 +/- 807 IU/L, and 121 +/- 53 IU/L vs 269 +/- 243 IU/L, respectively). These abnormalities persisted during the first week of respiratory failure, with significant differences in serum bilirubin and alkaline phosphatase between survivors and nonsurvivors (p less than 0.01). The degree of pulmonary and renal dysfunction was similar in both groups. These data suggest that liver function may be a major determinant of survival in patients with the adult respiratory distress syndrome.

Aged↗
PubMed1989

Pathophysiology of the congested lung.

The consequences of congestion, edema, and fibrosis on lung function of cardiac patients are reviewed. Special attention is paid to the physiologic alterations that may contrubute to the sensation of dyspnea.

Dyspnea↗
PubMed1988

A computerized classification technique for screening for the presence of breath biomarkers in lung cancer.

A simple computer-based screening technique has been developed for classifying human expired air components into 16 chemical classes, based on empirical formulas. The sort procedure was developed to simplify the screening of the composition of expired air samples by sorting all components into chemical classes and classifying components at the greater than 75% and greater than 90% occurrence levels. Both occurrence-rate components are then evaluated as diagnostic markers in a discriminant function model for their ability to detect lung cancer. Of the 386 components detected in the gas chromatography/mass spectrometry (GC/MS) data files, 45 components were present at the greater than 75% occurrence level and 28 components at the greater than 90% occurrence level. Thus, this preliminary sort routine, performed by using a simple macro program installed into a standard personal-computer spread-sheet, greatly reduces the amount of data required for statistical treatment. Such a sort routine can also be applied as easily to other complex GC/MS data files for the purpose of data reduction.

Biomarkers, Tumor↗
PubMed1987

Identification of isoprenoid-type components in human expired air: a possible shunt pathway in sterol metabolism.

Expired air samples have been analyzed from three groups of human subjects (normal, liver dysfunction, lung cancer) and the baboon (Papio anubus). Of the several hundred compounds present, three compounds were of particular interest due to their structural relationship to the isoprenoid-type intermediates in the sterol pathway. These compounds were 1-methyl-4-(1-methyl-ethenyl)-cyclohexene, 6-methyl-5-hepten-2-one, and 6,10-dimethyl-5,9-undecadien-2-one. Hydroxyacetone was also found in all samples screened. The relationship of these compounds to the non-sterol pathway of mevalonate metabolism is discussed.

Animals↗
PubMed1987

Ventilatory dysfunction in palatal myoclonus.

A patient with palatal myoclonus and involvement of respiratory muscles is described. Partial characterization of the mechanism of ventilatory dysfunction was achieved using noninvasive tests. Ventilatory dysfunction in this disorder can be manifested in different patterns depending on which respiratory muscles are involved predominantly.

Electromyography↗
PubMed1987

Hyperoxia-induced converting enzyme insufficiency in conscious rat: cardiovascular effects.

The effects of exposing rats to hyperoxia (100 percent O2) at normal atmospheric pressure for periods of 24-48 hours on components of the renin-angiotensin system and on blood pressure control were examined. Intrapulmonary conversion of angiotensin I (AI) to angiotensin (AII) was assessed using an isolated lung preparation perfused at constant flow. Exposure of rats to hyperoxia for 44-48 hours reduced single pass conversion of AI to AII in the pulmonary circulation from control levels of 82 +/- 4 to 29 +/- 5 percent (p less than 0.001). AII levels in trunk blood of 44-48 hour O2 exposed animals were 5.2 +/- 1.9 pg/ml, compared to 37.9 +/- 10.0 pg/ml in controls (p less than 0.001). Mean arterial pressure decreased significantly from 117 +/- 4.3 to 103 +/- 6.7 mmHg (p less than 0.05) in the O2 exposed group despite a threefold increase in plasma renin activity. The pressor response to exogenous AI was significantly diminished by O2 exposure, while the pressor response to exogenous AII remained unchanged from control. Pulmonary angiotensin-converting enzyme activity fell to approximately 50 percent of control in O2 exposed animals, but circulating converting enzyme activity was not change in this group. None of these alterations was apparent following 24 hours of hyperoxic exposure. These data suggest that O2 induced impairment in activity of angiotensin-converting enzyme at the endothelial membrane level has functionally significant effects on cardiovascular homeostasis, probably via reduced generation of endogenous AII.

Angiotensin I↗
PubMed1985

Volatile organic compounds in exhaled air from patients with lung cancer.

Using a specially developed breath collection technique and computer-assisted gas chromatography/mass spectrometry (GC/MS), we have identified in the exhaled air of lung cancer patients several volatile organic compounds that appear to be associated with the disease. The GC/MS profiles of 12 samples from lung cancer patients and 17 control samples were analyzed by using general computerized statistical procedures to distinguish lung cancer patients from controls. The selected volatile compounds had sufficient diagnostic power in the GC/MS profiles to allow almost complete differentiation between the two groups in a limited patient population.

Adenocarcinoma↗
PubMed1984

Reversible hypercapnic respiratory insufficiency in scleroderma caused by respiratory muscle weakness.

A patient with scleroderma presented with hypercapnic respiratory failure. Evaluation of pulmonary mechanics revealed severe restriction caused in part by respiratory muscle weakness. Treatment with prednisone corrected hypoventilation, improved symptoms, increased lung volumes, returned respiratory muscle strength to normal range, but did not change the degree of lung stiffness. This case demonstrates that restrictive patterns in scleroderma can be due to either lung or chest wall disease and that the latter may be reversible. If respiratory muscle weakness is present with restrictive ventilatory patterns in patients with scleroderma, a therapeutic trial of corticosteroid is warranted.

Humans↗
PubMed1983

Alveolar pressure in fluid-filled occluded lung segments during permeability edema.

In a model of increased hydrostatic pressure pulmonary edema Parker et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 44: 267-276, 1978) demonstrated that alveolar pressure in occluded fluid-filled lung segments was determined primarily by interstitial fluid pressure. Alveolar pressure was subatmospheric at base line and rose with time as hydrostatic pressure was increased and pulmonary edema developed. To further test the hypothesis that fluid-filled alveolar pressure is determined by interstitial pressure we produced permeability pulmonary edema-constant hydrostatic pressure. After intravenous injection of oleic acid in dogs (0.01 mg/kg) the alveolar pressure rose from -6.85 +/- 0.8 to +4.60 +/- 2.28 Torr (P less than 0.001) after 1 h and +6.68 +/- 2.67 Torr (P less than 0.01) after 3 h. This rise in alveolar fluid pressure coincided with the onset of pulmonary edema. Our experiments demonstrate that during permeability pulmonary edema with constant capillary hydrostatic pressures, as with hemodynamic edema, alveolar pressure of fluid-filled segments seems to be determined by interstitial pressures.

Animals↗
PubMed1983

Angiotensin-converting enzyme (ACE) in sepsis.

Angiotensin-converting enzyme (ACE) is localized to the luminal surface of pulmonary endothelial cells, where it converts angiotensin I and activates bradykinin. Sepsis may result in endothelial cell dysfunction. We have previously reported that the marked decrease in serum ACE in patients with the Adult Respiratory Distress Syndrome (ARDS) is present only in septic patients. Serum was evaluated in seven baboons made septic by the infusion of live E coli. There was a significant decline in serum ACE from a control value of 41.5 +/- 4.2 to 25.8 +/- 2.2 at 8 h (P less than 0.05), which correlated with the 65 +/- 11 torr decline in mean arterial pressure. There was no change in PaO2. We conclude that sepsis results in marked depletion of serum ACE activity, which corresponds to the decrease in mean arterial pressure, and may reflect reduced bradykinin inactivation.

Animals↗
PubMed1982

Gallium 67 citrate scanning and serum angiotensin converting enzyme levels in sarcoidosis.

Gallium 67 citrate scans and serum angiotensin converting enzyme (ACE) levels were obtained in 54 patients with sarcoidosis and analyzed in relation to clinical manifestations. 67Ga scans were abnormal in 97% of patients with clinically active disease (n = 30) and in 71% of patients with inactive disease (n = 24). Serum ACE levels were abnormally high (2 standard deviations above the control mean) in 73% of patients with clinically active disease and in 54% of patients with inactive disease. Serum ACE levels correlated significantly with 67Ga uptake score (r =.436; p less than .005). The frequency of abnormal 67Ga scans and elevated serum ACE levels suggests that inflammatory activity with little or no clinical expression is common in sarcoidosis. Abnormal 67Ga scans were highly sensitive (97%) but had poor specificity (29%) to clinical disease activity. The accuracy of negative prediction of clinical activity by normal scans (87%) was better than the accuracy of positive prediction of clinical activity by abnormal scans (63%). 67Ga scans can be used to support the clinical identification of inactive sarcoidosis.

Adult↗