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The COMPASS collaboration at CERN has investigated pion Compton scattering, π(-)γâπ(-)γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π(-)Niâπ(-)γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q(2)<0.0015 (GeV/c)(2). From a sample of 63,000 events, the pion electric polarizability is determined to be α(π)=(2.0±0.6(stat)±0.7(syst))×10(-4) fm(3) under the assumption α(π)=-ß(π), which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.
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OBJECTIVE: The objective of this paper is to describe baseline differences between obese and non-obese endometrial cancer survivor in anthropometrics, exercise behavior, fitness, heart rate and blood pressure, and quality of life, and to analyze whether the effect of a home-based exercise intervention on these outcomes differed for obese and non-obese participants. METHODS: One hundred post-treatment Stage I-IIIa endometrial cancer survivors participated in a single arm 6month study in which they received a home-based exercise intervention. Cardiorespiratory fitness, anthropometrics, and exercise behavior were measured every two months, and quality of life (QOL) and psychological distress were measured at baseline and 6months. RESULTS: Adjusting for potential confounders, at baseline obese survivors had poorer cardiorespiratory fitness (p=.002), higher systolic blood pressure (p=.018), and lower physical functioning (p<.001) and ratings of general health (p=.002), and more pain (p=.037) and somatization (.002). Significant improvements were seen in exercise behavior, resting heart rate, systolic blood pressure, and multiple QOL domains over the course of the intervention. Obese survivors had less improvement in exercise behavior and cardiorespiratory fitness than non-obese survivors, but there were no differences with regard to improvements in QOL and stress. CONCLUSIONS: Home based exercise interventions are beneficial to endometrial cancer survivors, including those whose BMI is in the obese range. While obese survivors have lower levels of physical activity and fitness, they experienced similar activity, fitness, quality of life and mental health benefits. Exercise should be encouraged in endometrial cancer survivors, including those who are obese.
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Neoplasias Endometriales/rehabilitación , Terapia por Ejercicio/métodos , Ejercicio Físico , Obesidad/complicaciones , Aptitud Física , Calidad de Vida , Adulto , Anciano , Presión Sanguínea , Índice de Masa Corporal , Estudios de Casos y Controles , Neoplasias Endometriales/complicaciones , Neoplasias Endometriales/psicología , Ejercicio Físico/psicología , Femenino , Conductas Relacionadas con la Salud , Frecuencia Cardíaca , Servicios de Atención de Salud a Domicilio , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Calidad de Vida/psicología , Estrés Psicológico , Resultado del Tratamiento , Circunferencia de la CinturaRESUMEN
Adeno-associated viral vector 9 (AAV9) has recently been shown to penetrate the blood-brain barrier via intravascular administration, making it a good candidate for diffuse gene delivery. However, the potential side effects of systemic delivery are unknown. Intrathecal viral vector administration may be more invasive than intravenous injections, but it requires far less vector and it can be performed on an outpatient basis, making it an ideal route of delivery for clinical translation. A total of 12 domestic farm pigs (<20 kg) underwent a single-level lumbar laminectomy with intrathecal catheter placement for AAV9 delivery. Animals were perfused and the tissue was harvested 30 days after treatment. Gene expression was assessed by anti-green fluorescent protein immunohistochemistry. Although a single lumbar injection resulted in gene expression limited to the lumbar segment of the spinal cord, three consecutive boluses via a temporary catheter resulted in diffuse transduction of motor neurons (MNs) throughout the cervical, thoracic and lumbar spinal cords. We now present the first successful robust transduction of MNs in the spinal cord of a large animal via intrathecal gene delivery using a self-complementary AAV9. These promising results can be translated to many MN diseases requiring diffuse gene delivery.
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Dependovirus/genética , Técnicas de Transferencia de Gen , Neuronas Motoras/metabolismo , Médula Espinal/citología , Porcinos , Transducción Genética , Animales , Vectores GenéticosRESUMEN
The COMPASS Collaboration at CERN has investigated the π- γ â π- π- π+ reaction at center-of-momentum energy below five pion masses, sqrt[s]<5m(π), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t'<0.001 GeV2/c2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3π-invariant mass m(3π)=sqrt[s] were extracted. The absolute cross section was determined in seven bins of sqrt[s] with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.
RESUMEN
The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190 GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1 GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66 GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0)) MeV/c2 and a width of (269±21(-64)(+42)) MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.
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Three-dimensional ultrasonograms prepared by superposition optical holography improves anatomical orientation and reduces the volume of data needed to study parenchymal organs such as breast, liver, kidney, spleen, and others. An optical hologram makes it possible to simultaneously view multiple planes of observations and see through and around structures without the superimposition of overlying structures. The use of pulse echo ultrasonograms results in better resolution and gray scale and permits multiplane viewing eliminates the geometric distortions present in acoustical holography.
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Holografía/métodos , Mamografía/instrumentación , Ultrasonido/instrumentación , Mamografía/métodos , UltrasonografíaRESUMEN
Jakarta Bay in Indonesia and its offshore island chain, the Thousand Islands, are facing extreme pollution. Surfactants and diesel-borne compounds from sewage and bilge water discharges are common pollutants. However, knowledge of their effects on reef fish physiology is scarce. This study investigated combined and single effects of a) the water accommodated fraction of diesel (WAF-D, determined by Æ©EPA polycyclic aromatic hydrocarbons (PAHs)) and b) the surfactant linear alkylbenzene sulfonate (LAS) on metabolic performance of the coral reef fish Siganus guttatus. Responses to combinations of each pollutant with elevated temperature (+3°C) were determined. Short-term exposure to WAF-D led to a significant decrease in standard metabolic rates, while LAS led to an increase. During combined exposure, metabolic depression was observed. Effects of pollutants were not amplified by elevated temperature. This study highlights the need to reduce import of these pollutants and to avoid negative long-term effects on fish health.
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Arrecifes de Coral , Gasolina/análisis , Perciformes/metabolismo , Tensoactivos/análisis , Temperatura , Contaminantes Químicos del Agua/análisis , Ácidos Alcanesulfónicos/análisis , Ácidos Alcanesulfónicos/toxicidad , Animales , Gasolina/toxicidad , Indonesia , Islas , Metaboloma/efectos de los fármacos , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Tensoactivos/toxicidad , Contaminantes Químicos del Agua/toxicidadRESUMEN
A cDNA coding for a 58-kD calcium-dependent calmodulin (CaM)-binding glutamate decarboxylase (GAD) previously isolated in our laboratory from petunia (Petunia hybrida) (G. Baum, Y. Chen, T. Arazi, H. Takatsuji, H. Fromm [1993] J Biol Chem 268: 19610-19617) was used to conduct molecular studies of GAD expression. GAD expression was studied during petunia organ development using the GAD cDNA as a probe to detect the GAD mRNA and by the anti-recombinant GAD serum to monitor the levels of GAD. GAD activity was studied in extracts of organs in the course of development. The 58-kD CaM-binding GAD is expressed in all petunia organs tested (flowers and all floral parts, leaves, stems, roots, and seeds). The highest expression levels were in petals of open flowers. Developmental changes in the abundance of GAD mRNA and the 58-kD GAD were observed in flowers and leaves and during germination. Moreover, developmental changes in GAD activity in plant extracts coincided in most cases with changes in the abundance of the 58-kD GAD. We conclude that the 58-kD CaM-binding GAD is a ubiquitous protein in petunia organs and that its expression is developmentally regulated by transcriptional and/or posttranscriptional processes. Thus, GAD gene expression is likely to play a role in controlling the rates of GABA synthesis during petunia seed germination and organ development.
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BACKGROUND: Large numbers of convicted drunk drivers are entering alcohol treatment programs, yet little information is available about their need for psychiatric treatment. This study of convicted drunk drivers estimates lifetime and 12-month prevalence of DSM-III-R psychiatric disorders (alcohol and drug abuse and dependence, major depressive disorder, dysthymic disorder, generalized anxiety disorder, posttraumatic stress disorder, and antisocial personality disorder) and compares rates with estimates from a US population-based survey. METHODS: Six hundred twelve women and 493 men, aged 23 to 54 years, convicted of driving while impaired, who had been referred to a screening program in Bernalillo County, New Mexico, were located and interviewed using the Diagnostic Interview Schedule between January 25, 1994, and June 30, 1997. Psychiatric diagnoses were compared with findings from the National Comorbidity Survey for the western region of the United States, conducted between September 14, 1990, and February 6, 1992. RESULTS: Eighty-five percent of female and 91% of male offenders reported a lifetime alcohol-use disorder, compared with 22% and 44%, respectively, in the National Comorbidity Survey sample. Thirty-two percent of female and 38% of male offenders had a drug-use disorder, compared with 16% and 21%, respectively, in the National Comorbidity Survey sample. For offenders with alcohol-use disorders, 50% of women and 33% of men had at least 1 additional psychiatric disorder other than drug abuse or dependence, mainly posttraumatic stress disorder or major depression. CONCLUSION: Drunk-driving offenders need assessment and treatment services not only for alcohol problems but also for drug use and the other psychiatric disorders that commonly accompany alcohol-related problems.
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Trastornos Relacionados con Alcohol/epidemiología , Conducción de Automóvil/legislación & jurisprudencia , Derecho Penal/legislación & jurisprudencia , Trastornos Mentales/epidemiología , Adulto , Alcoholismo/epidemiología , Trastornos de Ansiedad/epidemiología , Comorbilidad , Trastorno Depresivo/epidemiología , Escolaridad , Femenino , Encuestas Epidemiológicas , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Renta/estadística & datos numéricos , Masculino , Persona de Mediana Edad , New Mexico/epidemiología , Prevalencia , Clase Social , Trastornos Relacionados con Sustancias/epidemiología , Estados Unidos/epidemiologíaRESUMEN
A 52-year-old man with myxedema was evaluated for anterior chest pain that was considered to be compatible with myocardial ischemia. The night after admission he developed extreme bradycardia, hypotension, and apneic episodes lasting up to 25 s. Continuous positive airway pressure and administration of medroxyprogesterone acetate prevented further episodes and relieved much of the somnolence and lethargy that had contributed to the evidence for myxedema. Alveolar hypoventilation caused by decreased sensitivity to carbon dioxide, inadequate central neural drive, peripheral muscle force, and obesity all may have contributed to the apnea. Chest pain has not recurred, and results of electrocardiography have remained normal following full thyroid hormone replacement. The early recognition of myxedema causing sleep apnea will allow specific treatment to avoid the cardiovascular risks related to prolonged apnea and will help avoid confusion with other etiologies of cardiovascular abnormalities.
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Bradicardia/etiología , Mixedema/complicaciones , Síndromes de la Apnea del Sueño/etiología , Electrocardiografía , Humanos , Masculino , Persona de Mediana EdadRESUMEN
An essential first step in the purification of monoclonal antibodies is the clarification of the ascites fluid. While not ignored, this step has not received critical attention. Six different procedures were evaluated with respect to effectiveness and impact on several selected chemical components. For large-scale work, we find an on-line filtration process to be most efficient.
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Anticuerpos Monoclonales/aislamiento & purificación , Líquido Ascítico/química , Animales , Caprilatos , Centrifugación , Clorofluorocarburos de Metano , Filtración/métodos , Hibridomas , Ratones , Ratones Endogámicos BALB C , Dióxido de SilicioRESUMEN
A simple method for in vivo monitoring mucociliary tracheo-bronchial clearance is described. Eighteen healthy subjects and 13 patients with various chronic lung diseases were studied by this method. The principle of using an aerosol administration system similar to the system used for routine ventilation lung studies is stressed. Proximal large airway deposition of the radioaerosol was obtained by using relatively large particles (average diameter 2 microM) of [99mTc]MAA aerosol. Monitoring was performed by visual inspection of the tracheo-bronchial cinescintigraphic ascendence of the accumulated radioactive boli and by assessing their rate of clearance via automated computer analysis of the time-activity curves, following the movement of each bolus. The normal mean +/- s.d. clearance rate thus obtained was 4.7 +/- 1.3 mm/min. This rate appears to be more precise as compared with the range of results obtained by other radioisotopic methods. Significantly faster rates, mean 8.2 +/- 1.4 mm/min (p less than 0.001) were obtained in bronchiectatic patients while slower rates (2.8 mm/min) were seen in a patient with ciliary dyskinesia.
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Bronquios/diagnóstico por imagen , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Tráquea/diagnóstico por imagen , Adulto , Aerosoles , Anciano , Transporte Biológico , Bronquios/fisiología , Cilios/fisiología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Enfermedades Pulmonares/fisiopatología , Masculino , Persona de Mediana Edad , Moco/fisiología , Dosis de Radiación , Cintigrafía , Agregado de Albúmina Marcado con Tecnecio Tc 99m/administración & dosificación , Tráquea/fisiologíaRESUMEN
Ciliary beat frequency (CBF), measured in vitro, and tracheal mean clearance rate (TMCR), measured in vivo, were studied in 20 nonatopic nonsmokers. CBF, measured by direct examination of nasal cells obtained by a fiberbronchoscopic brush, was 12.1 +/- 1.7 Hz (mean +/- SD). TMCR, assayed by a radioisotope technique, revealed values of 4.3 +/- 1.1 mm/min (mean +/- SD). Both of these values agree with results published by other workers. We attempted to correlate intersubject variation in TMCR with variation in CBF but found no direct relationship, findings similar to those reported in studies done on frog palate epithelium.
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Moco/fisiología , Mucosa Nasal/fisiología , Tráquea/fisiología , Adulto , Transporte Biológico , Broncoscopía , Cilios/fisiología , Femenino , Tecnología de Fibra Óptica/instrumentación , Humanos , Masculino , Agregado de Albúmina Marcado con Tecnecio Tc 99mRESUMEN
Studies of mucociliary clearance were made on 17 patients with bronchiectasis and excessive sputum production. Tracheal mucus velocity was measured. Five patients with primary ciliary dysfunction and 12 who had no clinical evidence of this defect were studied. The mean (+/- SD) tracheal mucus velocity of the five patients with proved or presumptive primary ciliary dysfunction was 2.9 +/- 0.2 mm per minute and for the 12 patients without ciliary dysfunction, 7.9 +/- 1.4 mm per minute. (The previously determined rate for normals was 4.7 +/- 1.3 mm per minute.) In four of five patients with ciliary dysfunction, CBF was below 7.5 Hz while in the one patient of the 12 without ciliary dysfunction CBF was at the lower limit of normal values. Thus, mucociliary clearance responds to load, depends partly on CBF, and has a built-in control system and the means for compensating for ciliary dysfunction.
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Trastornos de la Motilidad Ciliar/fisiopatología , Depuración Mucociliar , Esputo/metabolismo , Tráquea/fisiopatología , Adolescente , Adulto , Anciano , Bronquiectasia/complicaciones , Bronquiectasia/fisiopatología , Cilios/fisiología , Trastornos de la Motilidad Ciliar/complicaciones , Femenino , Humanos , Síndrome de Kartagener/fisiopatología , Masculino , Persona de Mediana Edad , Agregado de Albúmina Marcado con Tecnecio Tc 99mRESUMEN
Eleven people accidentally inhaled a significant amount of a gaseous mixture of hydrogen chloride, phosphorus oxychloride, phosphorus pentachloride, oxalyl chloride, and oxalic acid. Clinical observations and laboratory tests were recorded from the time of admission throughout hospitalization. The main abnormalities were found in the respiratory tract and consisted of clinical and physiologic evidence of obstruction of the airways, mild interstitial and alveolar edema, a defect in diffusion, and inequalities of ventilation and perfusion that produced hypoxemia. All of these cleared within a short time.
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Aminoácidos/envenenamiento , Cloruros/envenenamiento , Ácido Clorhídrico/envenenamiento , Ácido Oxámico/envenenamiento , Accidentes de Trabajo , Adulto , Obstrucción de las Vías Aéreas/inducido químicamente , Exposición a Riesgos Ambientales , Femenino , Intoxicación por Gas/diagnóstico , Humanos , Hipoxia/inducido químicamente , Masculino , Persona de Mediana Edad , Edema Pulmonar/inducido químicamenteRESUMEN
The placing of a ventriculoatrial anastomosis because of elevated CSF pressure secondary to tuberculous meningitis resulted in repeated dissemination of Mycobacterium tuberculosis from the anastomosis. The consequent clinical picture showed recurrent appearance and clearing of miliary tuberculosis of the lung in spite of antituberculosis chemotherapy. While this possibility was considered early, the diagnosis was not established until the shunt was replaced shortly before the patient's death.
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Derivaciones del Líquido Cefalorraquídeo/efectos adversos , Tuberculosis Meníngea/terapia , Tuberculosis Miliar/etiología , Antituberculosos/uso terapéutico , Femenino , Atrios Cardíacos , Humanos , Embarazo , Complicaciones Infecciosas del Embarazo , Recurrencia , Tuberculosis Meníngea/complicaciones , Tuberculosis Miliar/complicaciones , Tuberculosis Miliar/tratamiento farmacológicoRESUMEN
BACKGROUND: Medical screening is used routinely to qualify and classify candidates for pilot training. The respiratory system assumes even greater importance owing to the increased stress of flying high-performance aircraft in a hostile environment characterized by high altitude, varying acceleration ("G" forces), and the possibility of rapid decompression. Any respiratory dysfunction may threaten the pilot's health, flight safety, and completion of the mission. Only those candidates with the highest psychophysical score are accepted to undergo special aeromedical screening. Physical suitability is an important factor in the selection and classification of candidates for flight training programs, and pulmonary function testing is central within this screening protocol. METHODS: We developed a respiratory algorithm for this unique screening process. The algorithm represents a practical and efficient approach for large-scale screening of healthy candidates for flight training. The algorithm deals with the major pulmonary health problems encountered in a previously screened healthy population aged 17 to 25 years. If by anamnesis, physical examination results, or baseline spirometry findings there is reason to suspect a respiratory problem that could emerge to endanger the pilot's life, a specially designed evaluation is performed according to the algorithm. We explain, step by step, the basis for each suggested test in order to reach a decision (operational specifications). The pulmonary function studies we recommend are reasonably priced and can be easily and reliably performed by regular medical staff technicians. The major justification for performing pulmonary function studies in a healthy population that has already gone through a preliminary medical screening and has been found fit is to identify occult or latent abnormalities. These abnormalities may have no or minimal clinical expression under ordinary circumstances but, under the stress of flight during the ensuing 5 to 10 years, may produce serious limitation in function. RESULTS: Two cases, seen in the Air Force Medical Center, are presented to illustrate how the algorithm is implemented. The algorithm has been in use for more than 5 years, and has been applied to the screening of several thousand candidates. Follow-up of the accepted candidates has not revealed any significant defects in the decision-making process. CONCLUSION: Use of the algorithm is highly cost-effective since it allows for nonspecialist physicians to carry out pulmonary screening and involves the pulmonary specialist only infrequently, ie, when a particularly complicated and/or borderline case is encountered. It is our contention that a similar algorithm would be useful in many other settings where large-scale screening is required.
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Medicina Aeroespacial , Algoritmos , Personal Militar , Pruebas de Función Respiratoria/métodos , Adolescente , Adulto , Análisis Costo-Beneficio , Humanos , Israel , Masculino , Pruebas de Función Respiratoria/economíaRESUMEN
One hundred one subjects living in northwest Hunan Province, People's Republic of China (PRC) were tested with histolyn, (Berkeley Biological Laboratories), spherulin (Berkeley Biological Laboratories), and tubersol (PPD 5 tuberculin units, Connaught Laboratories). Age of the tested subjects ranged from 16 to 58 years; 93 subjects were 22 years old or younger. Nine subjects reacted to histolyn with 5.0 mm or more induration, two subjects reacted to spherulin, and 34 subjects reacted to tubersol. One of the spherulin reactors also reacted to both histolyn and tubersol. The feasibility and advisability of doing a large-scale survey throughout the PRC seem clearly supported by this pilot project.
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Antígenos Fúngicos , Coccidioidina , Coccidioidomicosis/epidemiología , Proteínas Fúngicas , Histoplasmina , Histoplasmosis/epidemiología , Prueba de Tuberculina , Adolescente , Adulto , China/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
We examined the effect of physical training on cardiopulmonary function in 21 patients with chronic obstructive pulmonary disease and compared the results with similar observations in eight untrained patients. The training consisted of daily walking on a treadmill at increasing speeds and grades and other graded physical exercises. Evaluation of pulmonary function, including spirometric studies, lung volumes, and arterial blood gas levels, showed no significant change after training. Hemodynamic functions, including heart rate, cardiac index, stroke index, pulmonary vascular resistance, and arteriovenous oxygen content difference, were similarly unchanged at comparable submaximal loads. Pulmonary arterial wedge pressure increased after training in the treated group at rest and during exercise, but this may be related to changes in respiratory mechanics. Consumption of oxygen and minute ventilation decreased in the treated group during treadmill exercise, suggesting improved neuromuscular coordination and efficiency of walking on the treadmill. Total work performed on the treadmill increased significantly in the trained group. This increase was unexplained by physiologic observations but was thought to be due in part to increased efficiency of walking and increased motivation. We conclude that improvement in the capacity for exercise following physical training for four weeks is not associated with improvement in cardiopulmonary function at submaximal exercise.
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Corazón/fisiopatología , Hemodinámica , Enfermedades Pulmonares Obstructivas/fisiopatología , Pulmón/fisiopatología , Educación y Entrenamiento Físico , Presión Sanguínea , Gasto Cardíaco , Enfermedad Crónica , Frecuencia Cardíaca , Humanos , Enfermedades Pulmonares Obstructivas/rehabilitación , Enfermedades Pulmonares Obstructivas/terapia , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Consumo de Oxígeno , Circulación Pulmonar , Volumen Residual , Capacidad Pulmonar Total , Resistencia VascularRESUMEN
In the present era of direct monitoring of pressure in patients with chronic obstructive pulmonary disease (COPD), an appreciation of all factors that may influence the observed pulmonary vascular pressures is essential. Our study examines the impact of respiratory variations in intrathoracic pressure on the recorded pulmonary vascular pressures in 28 patients with COPD. Althouth pulmonary hypertension was present in only nine subjects at rest, all had an abnormal increase in the mean pulmonary arterial pressure during supine exercise. In 15 subjects, this abnormal response was, in part, related to an increase in pulmonary arterial wedge pressure to 15 mm Hg or more. The increase in pulmonary arterial wedge pressure was directly related to the amplitude of the peak-to-peak respiratory variation of such wedge pressure. This variation correlated with the specific airway resistance but was not related to the arterial oxygen pressure or pulmonary vascular resistance. These findings indicate the important influence of exaggerated respiratory effort on the measurement of pulmonary arterial wedge pressure and mean pulmonary arterial pressure in patients with chronic obstructive pulmonary disease.