Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034063 (pulmonary edema)
 10,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atrial Natriuretic Peptide (ANP) is secreted in response to hypoxia and pulmonary vasoconstriction. The hormone modulates pulmonary vascular tone in vivo and decreases pulmonary edema in isolated lungs exposed to several toxic agents. In addition, ANP improves the barrier function of endothelial cell monolayers in vitro. The plasma levels of ANP are elevated in patients with high-altitude pulmonary edema. We hypothesized that under these circumstances, ANP improves pulmonary gas exchange by attenuating the transvascular permeation of plasma (water). Therefore, we studied the effect of low-dose ANP in 11 healthy mountaineers exposed to hypoxia in a single-blind, placebo-controlled, cross-over design. During four 1-h periods, the subjects were stepwise exposed to decreasing barometric pressure, with a minimum of 456 mm Hg (simulated altitude, 4,115 m). Infusion of 5 ng/kg/min human-ANP increased the plasma ANP concentrations approximately twofold. The plasma concentrations of cyclic GMP, which is the second messenger of ANP, rose approximately threefold. Infusion of ANP did not affect the hemodynamic or ventilatory response to hypoxia. The hemoglobin concentration, however, rose from 9.0 +/- 0.1 to 9.4 +/- 0.1 mmol/L (p < 0.01) during ANP infusion but not during placebo infusion. The change in plasma volume calculated from this hemoconcentration indicated that approximately 10% of the plasma volume had permeated into the interstitium. Despite the observed whole-body hemoconcentration, oxygen saturation was significantly higher during ANP infusion than during placebo infusion (84.7 +/- 1.7 versus 79.6 +/- 1.8%, p < 0.05), and the alveolar-arterial oxygen difference was significantly lower (3.5 +/- 0.7 versus 7.3 +/- 0.8 mm Hg, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Atrial natriuretic peptide improves pulmonary gas exchange in subjects exposed to hypoxia. 839 37

Ascent to high altitude (HA) causes an increase in erythrocyte 2,3-diphsophoglycerate (DPG) and standard PO2 at 50% O2 saturation, PCO2 40 Torr, and blood pH 7.4 (P50,st). We studied the early phase of acclimatization to HA of mountaineers without and with a history of HA pulmonary edema. Tests were performed before ascent and after arrival at HA (4,559 m), approximately 22 h after the departure from low altitude (HA1) and on the following 3 days at HA (HA2-HA4). We investigated the relation between changes in DPG and P50,st, since at moderate altitude P50,st increases more rapidly than DPG, indicating that other factors may contribute to the change in P50,st. Combined effects of interaction between allosteric effectors of hemoglobin (Hb) (DPG, ATP, Cl) and Mg, which competes with Hb for DPG and ATP binding, might explain that phenomenon. Therefore concentrations of liganded Hb species were calculated from the total erythrocyte concentrations of the ligands by use of published binding constants and were related to changes in Hb-O2 affinity. P50,st increased at HA by approximately 4.5 Torr; the concentration of total DPG and ATP increased by 28 and 19%, respectively. Whereas P50,st reached a plateau already at HA1, the concentration of DPG reached its highest value at HA4. The erythrocyte Cl concentration decreased, whereas cellular Hb and Mg concentrations increased slightly. The sum of concentrations of all liganded Hb species increased, reaching 79% of its total change within 22 h after ascent; this can mainly be attributed to the change in the concentration of Hb[DPG] (+77% of total increase).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interactions between Hb, Mg, DPG, ATP, and Cl determine the change in Hb-O2 affinity at high altitude. 844 20

For centuries, medical practitioners had no electronic medical instruments and had to rely on their senses of sight, hearing, smell, taste, and touch to obtain physiologic measurements. Although it is possible to estimate blood pressure by palpating the pulse at the radial or brachial artery, such estimates are not accurate. Determining arterial oxygen saturation of hemoglobin is more complex: how "blue" a patient appears depends on skin coloration, lighting, and the examiner's sense of color. Finally, using radiographic images to validate pulmonary edema when clinicians suspect that there is an elevated left atrial or pulmonary artery wedge pressure also challenges human senses. However, today's medical instruments use transducers and signal processors to convert patient information into a form that clinicians can easily perceive and understand. This article defines terms used with biomedical instrumentation and discusses the components of ideal physiologic patient monitoring systems.
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PMID:Fundamentals of physiologic monitoring. 845 34

Mitomycin is a chemotherapeutic agent that is used to treat a variety of solid tumors. Pulmonary toxic reactions from this agent can be life threatening. We prospectively investigated the utility of pulmonary function tests (PFTs) in monitoring for the occurrence of pulmonary toxicity due to mitomycin. PFTs were obtained at baseline and after three cycles of mitomycin therapy. We analyzed the clinical course, radiologic studies, and PFT results in 133 patients with metastatic squamous cell carcinoma of the lung randomized to treatment with either mitomycin, vinblastine, and cisplatin or mitomycin alone as part of a prospective treatment protocol of the North Central Cancer Treatment Group (NCCTG). The diffusing capacity (DCO) was available in only 40 patients after the third cycle due to a high rate of progression and death from their underlying disease. After three cycles of chemotherapy, there was an average decline in the DCO of 14% (p<0.0001) and no changes were observed in expiratory flows. No differences were noted between treatment arms. A significant decline in the DCO (defined as a >20% change after correcting for hemoglobin) was noted in 11 of 40 patients (28%). This decline in the DCO was not associated with a worse prognosis (p=0.77). Seven patients (5%) developed severe pulmonary toxic reactions attributed to chemotherapy, including noncardiogenic pulmonary edema, interstitial pneumonitis, and pleural effusions. Corticosteroid therapy resulted in temporary subjective improvement in three patients. The Dco did not correlate with the development of pulmonary toxic reactions in these seven patients. In conclusion, (1) the incidence of clinically significant pulmonary toxic reactions from mitomycin is relatively low (5%), (2) mitomycin therapy resulted in a greater than 20% decline in the DCO in approximately one-fourth of patients receiving three cycles of chemotherapy, and (3) the use of serial PFTs in patients receiving mitomycin was not shown to be predictive of pulmonary toxicity.
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PMID:A prospective study of pulmonary function in patients receiving mitomycin. 863 74

Inhaled nitric oxide (NO) may modify surfactant either by interacting with the surfactant complex or by changing the capacity of the proteins of the epithelial lining fluid to inhibit the surface activity. Natural surfactant was exposed to NO (80 parts/million) in air in vitro while the gas-liquid surface was cycled. In the presence or absence of oxidants (Fe2+, xanthine, xanthine oxidase), surfactant exposed to NO retained the high surface activity significantly better than control surfactants exposed to air. Two surfactant inhibitors, hemoglobin (Hb) and albumin, were separately exposed to NO. In contrast to albumin, NO-exposed Hb and methemoglobin (MetHb; 16-125 micrograms/ml) decreased the surface activity at low surfactant concentrations, whereas native Hb had no effect. Surfactant recovered by sedimentation after exposure to MetHb had decreased surface activity and contained MetHb, whereas Hb did not bind to surfactant. Acidic phospholipid phosphatidylglycerol increased the binding of MetHb to surfactant. The MetHb-induced decrease in surface activity was elicited in the presence of surfactant proteins, including a peptide mimicking surfactant protein B. MetHb (but not Hb) added to a low dose of exogenous surfactant decreased the efficacy of surfactant to improve the lung compliance of premature rabbits. We propose that inhaled NO promotes the surface activity of surfactant during tidal ventilation and that, in high-permeability lung edema and surfactant deficiency, inhaled NO increases the inhibition of surface activity by converting Hb to MetHb in the alveolar space.
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PMID:A mechanism of nitric oxide-induced surfactant dysfunction. 880 11

Sprague-Dawley rats were compressed to 616 kPa (a) for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at baseline, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression; pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.
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PMID:Cardiopulmonary changes with moderate decompression in rats. 884 Apr 76

Malaria remains an overwhelming problem in tropical developing countries, with 300 to 500 million new cases and 1.5 to 3.5 million deaths per year. Malaria is a potentially life-threatening disease for travelers to the tropics. Imported malaria is an important clinical problem in nonendemic areas of the world because of increasing numbers of travelers, overseas workers, and immigrants from endemic areas. According to the World Health Organization's criteria, the recognition of one or more of the following clinical features should raise the suspicion of severe malaria: cerebral malaria (unrousable coma), severe anemia (hemoglobin <5 g/dL), renal failure (serum creatinine >3 mg/dL), pulmonary edema or adult respiratory distress syndrome, hypoglycemia (glucose <40 mg/dL), circulatory collapse or shock, disseminated intravascular coagulation, repeated generalized convulsions, acidosis (pH <7.25), macroscopic hemoglobinuria, hyperparasitemia (>5 percent of the erythrocytes infested by parasites), or jaundice (bilirubin >3 mg/dL). Although only a small proportion of patients with malaria develops severe manifestations, these patients require the most urgent and intensive care. Mortality among patients with cerebral malaria, even when treated in modern intensive care units, exceeds 30%, and when complicated by the adult respiratory distress syndrome, it may approach 80%. Among travelers, mortality remains a serious issue because of failure to obtain and use preventive measures, delay in seeking medical attention, and misdiagnosis.
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PMID:Imported severe falciparum malaria in Israel. 977 25

We investigated the feasibility and validity of near-infrared (NIR) spectroscopy for evaluation of acute lung injury (ALI). In an in vitro model simulating the spectrophotometric characteristics of the lung, NIR spectroscopy could precisely detect changes in water volume, suggesting its ability to assess the extent of pulmonary edema caused by ALI. The different grades of ALI were induced in rats by administering oleic acid and varying the pulmonary ventilation conditions, and NIR spectroscopy was employed to determine lung water content and hemoglobin (Hb) oxygenation of the lungs. NIR spectroscopy detected increased water content even in histologically mild ALI. The changes in lung water content measured by NIR spectroscopy were significantly correlated with gravimetric lung water content (r = 0.877, p < 0.0001). Deoxy-Hb measured by NIR spectroscopy consistently reflected the histological changes in the lungs, and the deoxy-Hb levels correlated with changes in SaO2 (r = -0.798, p < 0.0001). These findings demonstrate that NIR spectroscopy can evaluate lung water content and Hb oxygenation quantitatively, and may be a useful tool for assessing pathological status in ALI.
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PMID:Novel assessment of acute lung injury by in vivo near-infrared spectroscopy. 1039 Apr 18

Extrathoracic airways obstruction and scuba diving may induce pulmonary edema, probably because of increased hydrostatic transmural capillary pressure in the lung. This study was designed to examine the subacute pulmonary effects of the combined exposure to inspiratory resistive loading and immersion, as in scuba diving. Two groups each of eight healthy men were exposed to head-out water immersion in thermoneutral water for 40 min with or without an added inspiratory resistive load. At flows of 0.5 and 1.0 liter x s, the measured resistances were 4.4 and 9.0 hPa x s(-1) x liter(-1), respectively. Pulmonary function, including a flow-volume loop and transfer factor of the lung for carbon monoxide (Tlco, was measured before and 60 min after the end of the exposures. Body fluid balance was restored in the first 15 min after exposure, and Tlco was always corrected to a hemoglobin concentration of 146 g x liter(-1). There was a significant reduction in Tlco of 7.3+/-5.5% (P < 0.01) after the combined exposure to head-out water immersion and inspiratory resistive load. No changes in pulmonary function were seen after exposure to head-out water immersion or inspiratory resistive loading alone. The change in Tlco was normalized within 24 h. Submersion and resistance in breathing apparatus may contribute to the changes in pulmonary function seen immediately after dives. The nature of the exposure in these experiments and the time for recovery indicate that these changes are mechanically induced, and may not contribute to the long-term effects of diving on the lung.
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PMID:Subacute effects of inspiratory resistive loading and head-out water immersion on pulmonary function. 1048 13

Acute chest syndrome (ACS) is characterized by chest pain with dyspnea and recent radiologic abnormalities, and is an acute lung complication whose problem is one of etiology. Alveolar hypoventilation linked to infarcts of the thoracic ribs, thoracoabdominal trauma, subdiaphragmatic pain, the administration of analgesics causing respiratory depression, or sleep disturbance, is a frequent cause of ACS. Bronchoalveolar lavage has revealed the frequency of fat embolism following infarcts in the long bones. Pulmonary vascular occlusion, due to thrombosis or emboli, is rare, as are the infectious pneumonia and pulmonary edema. The pathogenetic mechanisms consist of an alteration of the rheological properties of the blood, the existence of an hypercoagulability state, specific interactions between the abnormal sickle cells and the vascular endothelium, and a dysregulation of the vascular reactivity. Research centered around NO biology has led to an expanded understanding of the critical interdependence of NO, hemoglobin, and the microvasculature. An anemic patient with ACS suffers from loss of pulmonary scavenging and hypoxic pulmonary vasoconstriction and loss of peripheral NO delivery. Interruption of this cycle by transfusing normal (hemoglobin A-containing) erythrocytes might improve all the abnormalities.
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PMID:[Respiratory distress and drepanocytosis]. 1079 55


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