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Biomedical subjects

G L Colice

Publications and source records attributed to G L Colice.

At least 19 recordsLinked to original sources
PubMed1996

Nebulized bronchodilators for outpatient management of stable chronic obstructive pulmonary disease.

The bronchodilator efficacy, safety, and persistence of effect of the anticholinergic agent ipratropium bromide and the beta-adrenergic agonist albuterol, both given by nebulization, were compared in 223 patients with stable, severe chronic obstructive pulmonary disease (COPD). The study was a randomized, double-blind, parallel group trial conducted over 85 days. Patients took the study drugs (either 500 micrograms of ipratropium bromide or 2.5 mg of albuterol) three times daily on an outpatient basis throughout the study. The acute bronchodilator responses to nebulized ipratropium bromide and albuterol were studied on days 1, 43, and 85. The forced expiratory volume in 1 second (FEV1) response was similar for both drugs on day 1 (33% peak increase after ipratropium bromide and 36% peak increase after albuterol). However, albuterol's effect on FEV1 decreased over time. Clinical improvement was noted in both study groups, but the ipratropium bromide group had a greater symptomatic benefit. Patients receiving ipratropium bromide scored higher on a quality-of-life questionnaire evaluating dyspnea, fatigue, emotional function, and mastery. Side effects were relatively infrequent and generally mild for both study drugs. These results show that ipratropium bromide, given by nebulization, is safe and effective in the outpatient treatment of COPD.

Administration, Inhalation↗
PubMed1996

Pathophysiological effects of hemodilution in chronic mountain sickness in rats.

We examined the effect of isovolemic hemodilution in a rat model of chronic mountain sickness (CMS). After 30 days at simulated high altitude (5,500 m), Hilltop rats had developed evidence of CMS: severe hypoxemia, polycythemia, and pulmonary arterial hypertension. Isovolemic hemodilution to a mean hematocrit of 46 +/- 5% was well tolerated by both the hypoxia-sensitive Hilltop rats and the companion Madison rat strain that does not develop CMS. After hemodilution, we found no evidence of sustained improvements in ventilation or gas exchange in either strain. Despite the fall in blood viscosity, cardiac output increased only marginally, and pulmonary arterial hypertension persisted in the Hilltop rats. Vascular hindrance increased after hemodilution, preventing a significant decline in pulmonary and systemic vascular resistances in the Hilltop rats. Blood O2 content and the coefficient of O2 delivery fell after hemodilution, but O2 consumption was sustained at a normal level after hemodilution by increasing the extraction fraction in the Hilltop strain. There was systemic hypotension through the first day of hemodilution, but this was the only apparent adverse effect of hemodilution. We conclude that isovolemic hemodilution was well tolerated despite the reduction in tissue O2 delivery. However, hemodilution failed to improve any of the respiratory and cardiovascular manifestations of CMS in Hilltop rats.

Altitude Sickness↗
PubMed1996

Hemoptysis. Three questions that can direct management.

Hemoptysis can be a life threatening condition on its own. It can also be a marker of serious disease or a recurrent problem accompanying lung cancer, bronchiectasis, or tuberculosis. A three-step approach is of fundamental importance: First, ensure that the lower respiratory tract is the source of bleeding. Second, identify cases representing serious risk. Third, consider both pulmonary and systemic circulation as possible sources of bleeding. In most cases, a non-specific, conservative approach is successful in managing hemoptysis, but occasionally, surgical resection or embolization of the bleeding vessel is required.

Hemoptysis↗
PubMed1995

Susceptibility to high-altitude pulmonary edema in Madison and Hilltop rats. I. Ventilation and fluid balance.

The pathogenesis of high-altitude pulmonary edema (HAPE) is not well understood. Ventilation and fluid-handling abnormalities at high altitude (HA) may play a role in HAPE. Because ventilatory and cardiopulmonary responses to chronic HA exposure in the Hilltop (H) strain of Sprague-Dawley rat are different from those in the Madison (M) strain, it was hypothesized that these strains would have different susceptibilities to developing HAPE. M and H rats were studied at sea level (SL) and in a hypobaric chamber after 9 and 12 h at a simulated altitude of 24,000 ft (barometric pressure = 295 mmHg) and 1, 12, and 24 h at a simulated altitude of 18,000 ft (barometric pressure = 380 mmHg). Both strains developed HAPE, but the M rat was more susceptible to HAPE, as demonstrated by a higher mortality rate from hemorrhagic pulmonary edema after 9 h at 24,000 ft and an earlier increase in lung water after exposure to 18,000 ft. Minute ventilation was similar in both strains at HA, but arterial PO2 was significantly higher in the M rat. Both strains had a significant decrease in fluid intake and negative sensible water balance at HA. No changes in plasma renin activity, aldosterone concentrations, antidiuretic hormone levels, and atrial natriuretic peptide levels were found at HA. The increased susceptibility of the M rat to HAPE is therefore not explained by ventilation or fluid-handling abnormalities.

Altitude↗
PubMed1995

The clinical evaluation for detecting metastatic lung cancer. A meta-analysis.

The objective of this study was to assess the performance of the clinical evaluation in detecting extrathoracic metastases compared with brain and abdomen CT and radionuclide bone scans in patients with newly diagnosed bronchogenic carcinoma. The included studies were selected using the MEDLARS database from 1977 through August 1992 as well as reference lists from published articles or abstracts. Studies eligible for consideration met six criteria. The most important criterion was that results of a clinical evaluation and a CT scan of the head or abdomen or a radionuclide bone scan, obtained during the initial evaluation of a patient with primary lung cancer, must be included. Data were categorized by the type of clinical evaluation performed and whether patients had a clinical evaluation suggesting metastases (positive) or not (negative). The negative predictive value (NPV) of the clinical evaluation was calculated in all studies. The sensitivity, specificity, and the positive predictive value (PPV) were calculated in studies including positive and negative clinical evaluation patients. Twenty-five studies are included in this analysis. A total of 3,089 imaging scans were obtained in the study patients after a clinical evaluation was performed. The mean NPV of the clinical evaluation for CT of the brain, abdomen, and radionuclide bone scan is 95, 94, and 89%, respectively. When an expanded clinical evaluation was performed, the NPV was even higher. The NPV was influenced by the prevalence of metastases, but still performed well in series with high prevalence rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Neoplasms↗
PubMed1995

Cost-effectiveness of head CT in patients with lung cancer without clinical evidence of metastases.

OBJECTIVE: To estimate the cost-effectiveness of CT for detecting brain lesions in patients with lung cancer without clinical evidence of metastases. DESIGN: Decision analysis model comparing two different strategies for detecting brain metastases: brain CT routinely (CT-first) or brain CT only when patients develop neurologic signs and/or symptoms (CT-deferred). PATIENTS: Hypothetical cohort of patients with lung cancer with an unremarkable screening clinical evaluation for metastases. MEASUREMENTS: Net costs are calculated as the difference in costs between the two limbs of the decision tree. Net benefits are expressed as the difference in calculated years of life expectancy between the two strategies. Net costs are divided by net benefits, yielding the marginal cost per quality adjusted year of added life expectancy (C/QALY) for the CT-first strategy. RESULTS: In the baseline analysis, the C/QALY for the CT-first strategy is about $70,000. Improving the clinical evaluation as a screen for detecting brain metastases markedly increases the C/QALY. Increasing the cost of brain CT magnifies this effect. More effective treatment for asymptomatic brain metastases and better accuracy of CT for identifying resectable and unresectable brain metastases lower C/QALY. CONCLUSIONS: Although a threshold cost-effectiveness has not been defined for identifying "cost-effective" diagnostic procedures, the marginal C/QALY of the CT-first strategy is substantially higher than many accepted medical interventions. At current costs, the routine use of brain CT is not warranted in patients with lung cancer who have normal findings on a standardized clinical evaluation for metastases.

Brain Neoplasms↗
PubMed1995

Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries.

The pathogenesis of high-altitude pulmonary oedema (HAPE) is disputed. Recent reports show a strong correlation between the occurrence of HAPE and pulmonary artery pressure, and it is known that the oedema is of the high-permeability type. We have, therefore, proposed that HAPE is caused by ultrastructural damage to pulmonary capillaries as a result of stress failure of their walls. However, no satisfactory electron microscopy studies are available in patients with HAPE, and animal models are difficult to find. Madison strain Sprague-Dawley rats show a brisk pulmonary pressure response to acute hypoxia and are susceptible to HAPE. We exposed 13 Madison rats to a pressure of 294 torr for up to 12.5 h, or 4 rats to 236 torr for up to 8 h. Pulmonary arterial or right ventricular systolic pressures measured with a catheter increased from 30.5 +/- 0.5 (SEM) in controls (n = 4) to 48 +/- 2 torr (n = 11). The lungs were fixed for electron microscopy with intravascular glutaraldehyde. Frothy bloodstained fluid was seen in the trachea of three animals. Ultrastructural examination showed evidence of stress failure of pulmonary capillaries, including disruption of the capillary endothelial layer, or all layers of the wall, swelling of the alveolar epithelial layer, red blood cells (RBCs) and oedematous fluid in the alveolar wall interstitium, proteinaceous fluid and RBCs in the alveolar spaces, and fluid-filled protrusions of the endothelium into the capillary lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Altitude Sickness↗
PubMed1995

Pulmonary tuberculosis. Is resurgence due to reactivation or new infection?

Spread of tuberculosis consists of three phases: In the transmission phase, Mycobacterium tuberculosis is transferred from a source of a host via aerosolization of respiratory secretions. During the infective phase, the organism establishes itself within the lung of the new host. In the pathogenetic phase, organism- and host-related mechanisms bring about clinical disease. In the past, the vast majority of cases of tuberculosis in the United States were assumed to be reactivation of dormant disease. However, the pathogenesis has increasingly shifted to progressive primary disease. This shift may be due to the low endogenous resistance to tuberculosis in native-born Americans. In addition, various social problems, especially in large cities, favor person-to-person transmission. Infectivity of M tuberculosis itself may be increasing as strains resistant to multiple agents become more common.

AIDS-Related Opportunistic Infections↗
PubMed1993

Detecting the presence and cause of pulmonary edema.

Prompt recognition of pulmonary edema is important to avoid life-threatening complications. Chest radiography and other tests are key to establishing the diagnosis and distinguishing between the two types of pulmonary edema--cardiogenic and noncardiogenic. Dr Colice discusses the mechanisms that lead to pulmonary edema, the various diagnostic methods, prognosis, and management.

Capillary Permeability↗
PubMed1993

Salt loading test in a population adapted to moderately high altitude living (3,000 m).

The sodium excretory capacity of normal subjects acutely mobilized from sea level to moderately high altitude was compared to native subjects adapted to high altitude living (3,000 meters). This study was conducted in order to provide insights into hormonal adaptations associated with acute mobilization to a hypoxemic environment and to try to determine how these variables could influence the renal handling of a salt load. A standard amount of 5% NaCl solution at a volume of 100 ml/m2 BSA was infused over a 30-min period to all subjects. Urine collections were obtained periodically over the next 3 h. Subjects adapted to moderately high altitude living were able to excrete a salt load faster than unadapted subjects (57.1 vs. 32.9 mmol.m-2.h-1, respectively). No change in plasma atrial natriuretic factor (ANF) concentration in either group of subjects was observed during the salt administration period. Adapted individuals had significantly higher baseline levels of antidiuretic hormone (ADH). The high altitude natives enhanced excretory response to a salt load was not explained by any observed hormonal changes and their lack of increased ADH release to serum osmolar changes was unexplained.

Adaptation, Physiological↗
PubMed1993

Hormonal response to exercise in high altitude natives and COPD patients.

Plasma renin activity (PRA) and aldosterone increase with exercise. Acute hypoxia interferes with this hormonal response to exercise, but the effects of chronic or intermittent hypoxia on exercise-induced hormonal changes are not well understood. The hormonal response to exercise was studied in two groups of subjects who were expected to become hypoxic during exercise (high altitude natives at high altitude and patients with moderate to severe chronic obstructive pulmonary disease or COPD), and normal controls. Both the high altitude natives and COPD patients became hypoxic with maximal exercise. The rate of rise of PRA and epinephrine was significantly less in the two study groups than the normal subjects. Changes in aldosterone levels with exercise were similar to PRA but the differences among groups were not significant. Differences between the groups were not seen for changes in atrial natriuretic polypeptide and norepinephrine during exercise. These results support the concept that hypoxia interferes with the renin-aldosterone and adrenal medullary response to exercise.

Adult↗
PubMed1992

Resolution of laryngeal injury following translaryngeal intubation.

Translaryngeal intubation (TLI) causes mucosal ulcerations of the vocal cords and posterior laryngeal commissure. Usually these ulcers heal by primary reepithelialization, but occasionally laryngeal granulomas or strictures develop at these ulcer sites. The incidence of granuloma and stricture formation and the variables influencing abnormal laryngeal healing following TLI are not well understood. A group of 54 patients who experienced prolonged TLI were followed prospectively to determine the resolution rate of laryngeal injury. Direct fiberoptic laryngoscopy was performed at either extubation or tracheostomy and repeated every 2 wk until the larynx returned to normal or a persistent laryngeal abnormality was identified. Laryngeal symptoms were assessed at these same time points. In 5 patients (9%) the appearance of the larynx was normal at extubation, and in 42 patients (78%) laryngeal healing occurred by primary reepithelialization within 8 wk. Four patients (7%) developed laryngeal granulomas, which required surgical removal in all but one case. No patients in this series developed laryngeal strictures. Three patients (6%) died before complete follow-up. Laryngeal symptoms, particularly hoarseness, resolved as the larynx healed. Performance of tracheostomy, age, TLI for more than 10 days, and severe laryngeal injury at extubation did not influence the median time to resolution of laryngeal abnormalities. Abnormal laryngeal healing following TLI is uncommon but is not exacerbated by prolonged TLI (more than 10 days), severe laryngeal injury at extubation, or performance of a tracheostomy.

Humans↗
PubMed1992

Impact of dyspnea and physiologic function on general health status in patients with chronic obstructive pulmonary disease.

STUDY OBJECTIVE: To examine the relationship among clinical dyspnea ratings, physiologic pulmonary function, and general health status in symptomatic patients with chronic obstructive pulmonary disease (COPD). DESIGN: Observational data collected at a baseline state. SETTING: Outpatient pulmonary disease clinics at a university hospital and two VA medical centers. PATIENTS: One hundred ten male patients with COPD with no significant comorbidity were recruited. MEASUREMENTS AND RESULTS: Clinical ratings of dyspnea were measured by the multidimensional baseline dyspnea index (BDI). Pulmonary function tests included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximal inspiratory mouth pressure (PImax). General health status was assessed with the Medical Outcomes Study short-form survey, which consists of 20 questions that cover six health components. The mean age of the patients was 67 +/- 8 yr (+/- SD). The mean value for FVC was 2.84 +/- 0.84 L (68 +/- 18 percent of predicted), for FEV1 was 1.28 +/- 0.59 L (44 +/- 17 percent of predicted), and for PImax was 59.0 +/- 25.0 cm H2O. The BDI score and PImax were significantly correlated with five of the six components of general health status. Only three of the six components of general health were significantly correlated with FEV1 as percent predicted (rs value range, 0.30 to 0.44) and with FVC as percent predicted (rs value range, 0.25 to 0.33). Statistical comparisons showed that the BDI score had significantly higher correlations than FVC (percent predicted), FEV1 (percent predicted), and PImax values with physical functioning and role functioning. Multiple linear regression analysis showed that the BDI score was the only statistically significant predictor of role functioning, mental health, and health perceptions for general health status, whereas both the BDI score and FEV1 (percent predicted) were independent predictors of physical functioning and social functioning. CONCLUSION: Dyspnea ratings influence and predict general health status to a greater extent than do physiologic measurements in symptomatic patients with COPD. A shift in focus from the pathophysiology of disease to assessment and relief of symptoms may provide more meaningful benefits for the individual patient in terms of quality of life. This consideration requires that health-care providers use available measuring tools in clinical practice to quantify symptoms, as well as overall health status.

Adult↗
PubMed1992

The relationship of clinical findings to CT scan evidence of adrenal gland metastases in the staging of bronchogenic carcinoma.

OBJECTIVE: To determine whether, during the staging of newly diagnosed bronchogenic carcinoma, clinical indicators predict the presence or absence of adrenal metastases detected by computerized tomographic (CT) scans. DESIGN: Retrospective review of charts and roentgenograms. SETTING: Academic medical center. PATIENTS: Two hundred five consecutive patients diagnosed with bronchogenic carcinoma, of whom 173 had sufficient data available for analysis. MEASUREMENTS: Charts were reviewed for abnormalities in three clinical categories (signs, symptoms, and routine laboratory tests) and the presence of extrapulmonary tumor spread. The CT scans were reviewed for evidence of adrenal involvement by radiologists blinded to clinical findings. MAIN RESULTS: Thirty patients had abnormal adrenal glands on CT scan. In 26 the abnormality was believed to represent adrenal metastasis, whereas in four the CT findings were consistent with adrenal adenomas. The frequency of adrenal metastases varied with the number of positive, clinical findings (chi 2 = 105.4; p < 0.001). All 26 patients with adrenal metastases had at least one clinical abnormality, and 21 (81 percent had abnormalities in either two or all three clinical categories. In 40 patients without any clinical indicators of widespread disease, none had CT evidence of adrenal metastases. The presence of adrenal metastases also varied with the extent of coexistent disease (chi 2 = 111.82; p < 0.001). Eighty-one percent (21) of the patients with and 18 percent of those without adrenal metastases had both intrathoracic and extrathoracic involvement. CONCLUSIONS: Our findings indicate that adrenal metastases are found in patients with a large tumor burden who have clinical indicators of widespread disease. We found no evidence of adrenal metastases by CT in any patient with a normal clinical evaluation. We conclude that CT scans through the adrenal glands are unnecessary when staging newly diagnosed bronchogenic carcinoma if the findings from the initial clinical evaluation are normal.

Adrenal Gland Neoplasms↗
PubMed1992

Effects of hypoxemia at sea level and high altitude on sodium excretion and hormonal levels.

Acute hypoxemia at sea level is associated with decreased aldosterone secretion. This inhibition is thought to be mediated through secretion of atrial natriuretic factor (ANF). The interaction of these two hormones should result in enhanced renal salt excretion during hypoxemic conditions. This hypothesis was tested by administration of a standardized salt load to seven normal subjects during normoxemia at sea level (SL), acute hypoxemia (AH) at sea level, and high altitude (HA) (3,000 m). Urine and venous blood samples were collected and analyzed. A natriuresis and diuresis was observed only under AH conditions. It was accompanied by a decrease in plasma aldosterone levels, but did not correlate with changes in plasma aldosterone levels, ANF, or other hormones. Increased plasma renin activity (PRA) and increased norepinephrine levels were encountered at HA, suggesting sympathetic nervous system activation. No change in anti-diuretic hormone (ADH) levels with increased plasma osmolality was seen at HA. We conclude that excretion of a salt load during normobaric hypoxemia is enhanced by a decrease in plasma aldosterone levels, unrelated to changes in ANF or other hormones. The differences observed in norepinephrine, PRA, and ADH levels during HA versus AH conditions suggest that hypobaria or chronic hypoxemia may influence these hormonal responses.

Acute Disease↗
PubMed1992

Blood biochemical characteristics of cattle at sea level and at moderately high altitude (3,000 m).

We investigated the biochemical composition of blood from Holstein cows, native breed (criollas), and cows descended from fighting bulls (Vacas de lidia) raised at an altitude of 3,000 m (moderately high altitude, MHA), and compared the results with those from Holsteins and cows of similar genetic ancestry as the criollas (scrub cows), both raised at sea level (SL), to determine blood biochemical values characteristic of adaptation to high altitude. Only potassium and calcium concentrations were similar among groups. Glucose concentration was lower in MHA cows, with the exception of Vacas de lidia. Serum bicarbonate concentration was lower in MHA cows; this finding can be explained by hyperventilation in the hypoxic environment. Serum magnesium concentration was lower in SL and MHA Holsteins than in other groups. Serum phosphate concentration was lower in scrub cows, MHA Holsteins, and criollas than in other groups. Cholesterol concentrations were lower in SL Holsteins, whereas triglycerides were higher in scrub cows and MHA Vacas de lidia. Concentration of high-density lipoprotein was significantly greater in Vacas de lidia and less in MHA criollas than in the other groups. Uric acid and total protein were higher in MHA groups. Using radioimmunoassay for human proteins, thyroxine-binding globulin was undetectable. Total and free thyroxine and free triiodothyronine were higher in scrub cows, followed by Vacas de lidia; lower values were detected in SL and MHA Holsteins and MHA criollas.

Altitude↗
PubMed1991

Does the mediastinum of patients with non-small cell lung cancer require histologic staging? Future standards for computed tomography.

We asked whether noninvasive staging of the mediastinum is a reasonable alternative to invasive staging in patients with non-small cell lung cancer. Decision analysis was used to compare strategies relying upon mediastinoscopy, bronchoscopy with transbronchial needle aspiration, and/or thoracotomy for histologic or cytologic confirmation of mediastinal stage to two strategies primarily relying upon computed tomography for assessing the mediastinum. Life expectancy was the outcome of interest. Extensive sensitivity analysis showed that, if the specificity of computed tomography for mediastinal disease was above 0.90, a strategy primarily relying upon computed tomography to stage the mediastinum would provide a life expectancy within 1 month of that provided by invasive testing. The difference in life expectancy between the invasive and noninvasive staging strategies decreased further as the prior probability of unresectable disease increased. Surprisingly, the sensitivity of computed tomography for mediastinal disease was of little importance in determining overall life expectancy. These results suggest that noninvasive imaging techniques might reliably replace invasive mediastinal staging if their specificity exceeds 0.90.

Carcinoma, Non-Small-Cell Lung↗