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Biomedical subjects

T L Petty

Publications and source records attributed to T L Petty.

At least 19 recordsLinked to original sources

Urinary levels of bombesin-like peptides in asymptomatic cigarette smokers: a potential risk marker for smoking-related diseases.

Bombesin-like peptides (BLP) produced by pulmonary neuroendocrine cells have many physiological actions which are relevant to the pathobiology of cigarette smoking. The objectives of this study were to determine whether cigarette smokers excrete increased levels of BLP in their urine compared with nonsmokers, to determine the relationship between BLP levels in urine and bronchoalveolar lavage (BAL) fluid, and whether urinary BLP levels are merely a reflection of exposure to cigarette smoke. Simultaneous BAL fluid and urine samples were obtained from ten clinically normal smokers and 22 normal nonsmoker volunteers. Urine samples were also obtained from 39 normal smokers and 30 normal nonsmokers who did not have BAL performed. BLP levels were measured in urine and BAL fluid using an enzyme-linked immunoassay. Expired air content of carbon monoxide, which reflects recent exposure to cigarette smoke, was determined in 34 of the clinically normal smokers and correlated with urinary BLP levels. We found that, in addition to having increased BLP levels in BAL fluid (P = 0.04), asymptomatic cigarette smokers also have increased BLP levels in their urine compared with normal nonsmokers (P = 0.007). Of note, a subgroup of smokers have markedly increased BLP levels which do not overlap with the nonsmokers. Urinary BLP levels correlated with expired air content of carbon monoxide (r = 0.49, P less than 0.01). However, not all smokers with increased expired air content of carbon monoxide exhibited increased BLP levels. Finally, all smokers with detectable BLP levels in BAL fluid had detectable urinary BLP levels, and there was a positive correlation between BLP levels in urine and BAL fluid (r = 0.625, P less than 0.001). We conclude that a subgroup of asymptomatic cigarette smokers exhibited increased BLP levels, measurable in both urine and BAL fluid, which precede the onset of clinically detectable disease and which are not strictly dependent on smoking intensity. We speculate that smokers with increased BLP levels may have a greater risk for smoking-related diseases.

Biomarkers

Unilateral pulmonary edema.

Awareness of pathophysiology and differential diagnosis of this entity is crucial for management. Edema may be ipsilateral or contralateral to the perfusion defect, or may be variable. A variable case is presented.

Adult

Transdermal clonidine reduced some withdrawal symptoms but did not increase smoking cessation.

BACKGROUND: Clonidine may be useful in controlling tobacco withdrawal and in facilitating smoking cessation. This study was developed to test the efficacy of transdermal clonidine in promoting smoking cessation. METHODS: We conducted a five-center, double-blind, placebo-controlled, randomized controlled trial of transdermal clonidine in conjunction with a minimal behavioral intervention for smoking cessation. The intervention was based on the American Lung Association's Freedom From Smoking program. Self report of not smoking was validated with exhaled air carbon monoxide of less than 8 ppm and salivary cotinine of less than 20 ng/mL. Transdermal clonidine therapy began 1 week before the target quit date: 0.1 mg/24 h for the first 4 days increasing to 0.2 mg/24 h for the next 3 days, if the lower dose was tolerated. The highest tolerated dose was then continued for 6 weeks after target quit day. Withdrawal symptoms were measured daily for the first 7 days after target quit day. RESULTS: A total of 213 patients were enrolled (106 active drug and 107 placebo). During the study, 15.5% of patients had drug therapy discontinued due to adverse effects, 24.5% (26/106) taking active drug vs 8.4% (9/107) receiving placebo. There was a significant reduction in anxiety score from 3.0 to 2.4 (placebo vs active) and irritability score from 2.2 to 1.7 (placebo vs active) during the first week after cessation. There was no reduction in other withdrawal symptoms. The overall 12-week abstinence rate was 33.0% (35/106) in the active drug group vs 34.5% (37/107) in the placebo group (not significant). CONCLUSION: This study demonstrated some reduction in early withdrawal symptoms with the use of a clonidine transdermal patch, but no increase in cessation rate, 6 weeks after medication had been discontinued.

Administration, Cutaneous

Reinforcing breath carbon monoxide reductions in chronic obstructive pulmonary disease.

Chronic Obstructive Pulmonary Disease (COPD) usually results from tobacco smoking. Smoking cessation slows COPD's progression, but few have studied anti-smoking treatments in COPD. In 3-month trials we paid lottery tickets during daily home visits to still-smoking COPD patients for reductions in breath carbon monoxide (CO), a measure of smoke intake. In our first protocol experimental patients received 0-3 tickets per day, depending upon the extent of CO reduction below pre-treatment baselines; yoked controls received the same number of tickets, but not contingent on CO. The protocol produced no change. In a second study patients were assigned a post-baseline quit-date, received nicotine gum, and were paid up to 5 tickets per night, but only for CO less than 10 parts per million (ppm). CO fell sharply as the intervention began, but gradually rose again. A third protocol added special reinforcement schedules for those who did not quit or relapsed (up to 20 tickets per night for CO less than 10 ppm). Daily CO concentrations fell from 27.1 parts per million (baseline mean) to 12.7 (intervention mean), but rapid increases followed the intervention. Few patients stopped smoking, but CO and cigarettes used per day significantly fell during Studies 2 and 3. Post-hoc analysis suggested only a small effect from gum.

Breath Tests

What to do when an x-ray film suggests lung cancer.

The chest film is one of the most common methods of detecting lung cancer, which often appears as solitary nodules or hilar masses. Once the diagnosis is established, the most effective treatment can be determined and staging of the tumor can be done. Surgical resection is the only cure for non-small-cell carcinoma, although radiotherapy and chemotherapy may shrink some tumors. Because 90% of all cases are caused by smoking, a preventive approach to the disease is crucial. Screening of high-risk patients (ie, smokers with airflow obstruction) using chest films and sputum cytology may aid this approach.

Carcinoma

Pulmonary medicine.

Explore the source record for details and available documents.

Pulmonary Medicine

Home oxygen--a revolution in the care of advanced COPD.

The state-of-the-art of oxygen delivery to the home has evolved remarkably in the past 25 years. Oxygen is established as not only safe but effective in selected patients with advanced COPD. Oxygen clearly has been shown to improve both the length and quality of life in many patients. Hospitalizations can be reduced by the use of home oxygen therapy. This appears to be most likely in ambulatory patients receiving long-term oxygen from portable liquid systems. It is likely that further advances will make home oxygen more suitable, acceptable, and perhaps less costly for a growing number of patients with progressive chronic respiratory diseases in whom significant hypoxemia and organ system damage are present.

Home Care Services

Florid pulmonary veno-occlusive disease.

A young woman presented with rapidly progressive dyspnea and clinical findings strongly suggestive of primary pulmonary hypertension or possible pulmonary embolism (or both). She died of acute right-sided heart failure. A diagnosis of pulmonary veno-occlusive disease was made at autopsy. Approximately 100 cases of this disease have been reported previously in the literature. We describe a patient with a particularly florid progression of this unusual disease. Death occurred within six weeks of the onset of symptoms.

Adult

Acute respiratory distress syndrome (ARDS).

The acute respiratory distress syndrome (ARDS) is a common clinical catastrophe following acute lung injury. A multiplicity of clinical states can lead to ARDS. A new classification system has been proposed to deal with associated organ system failure and varying degrees of acute lung injury. ARDS is a permeability and inflammatory edema with damage and destruction at the air blood interface. Many cellular and humoral mediators probably attack the lung's surfactant system which in turn enhances edema formation. Supportive care with mechanical ventilation and positive end expiratory pressure results with the salvage of less than 50% of patients. Lung regeneration requires weeks or months to become complete in those who survive. Thus far no individual pharmacological agents have been shown to alter prognosis. Controlled clinical trials are required to evaluate new and older pharmacological agents alone or in combination, and surfactant replacement.

Humans

A historical perspective of mechanical ventilation.

The fascinating history of mechanical ventilation reveals many approaches to support failing respiration. New technologies continue to evolve. Understanding the intricacies of the patient-machine interface and the use, abuse, and mystique of certain methods of mechanical ventilation such as positive end expiratory pressure (PEEP) are considered in this article. The future promises exciting new approaches in mechanical ventilation.

History, 20th Century

Definitions in chronic obstructive pulmonary disease.

States of airflow obstruction are common disorders which span the spectrum from asthmatic-chronic bronchitis to emphysema. Asthmatic and chronic bronchitic states are at least potentially reversible by systematic, pharmacologically oriented therapy focusing on bronchodilators and corticosteroids. Both asthmatic bronchitis, particularly when it is not adequately treated, and emphysema result in the final common pathway of COPD. These are generally progressive states, unless smoking cessation can be achieved in early or mild stages of disease. The future focuses on the great challenge of early identification, classification, and intervention. Thus, all patients with cough, dyspnea, and wheeze should be carefully evaluated by health workers who understand the history, physical examination, and simple pulmonary function tests in the context of chest radiology. These clinical methods together can help define the disease states characterized by airflow obstruction. Often, a final definition of disease cannot be made until aggressive attempts at the treatment of the airflow obstruction and its attendant symptoms complex have been vigorously pursued by experienced clinicians.

Adult

The elastic properties of lobes of excised human lungs.

Static pressure-volume curves were obtained from the upper and lower lobes of 5 excised human lungs. Comparison of the upper and lower lobe pressure-volume curves showed a small but significant difference. The upper lobes contained a greater percentage of total lobar capacity above approximately 80 per cent of the lung volume. It would thus appear that the difference in lobar elastic properties could influence ventilation distribution in normal humans.

Adult