Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Perfluorooctyl bromide is an oxygen-carrying perfluorocarbon presently under development as an artificial blood substitute (Oxygent HT). Intravenous (i.v.) Oxygent HT elicits a mild side-effect profile in man characterized by early onset headache and nausea and delayed onset fever. Early onset flushing has also been observed. Species of Artiodactyla are sensitive to particulate injections and demonstrate a transient pulmonary hypertensive response thought to be associated with the large number of pulmonary intravascular macrophages found in these species. Because of this sensitivity, we chose the swine as a model for further investigations. In anesthetized and conscious swine, i.v. Oxygent HT transiently increased mean pulmonary artery pressure (mPAP) and caused flushing. Both effects peaked at 30 min post injection and were resolved by 2 hrs. Plasma thromboxane B2 (TxB) increased in response to Oxygent HT. Oxygent HT-induced changes in mPAP, flush, and plasma TxB were blocked by aspirin and ibuprofen. Dexamethasone and SQ 29,548 (thromboxane receptor antagonist) blocked the mPAP increase. In conscious swine, Oxygent HT caused a febrile response which was blocked by ibuprofen or dexamethasone. Thus, both early- and late-onset effects of Oxygent HT in swine are blocked by interference with the arachidonic acid cascade. These findings suggest that the 2-phase "flu-like" syndrome induced by Oxygent HT is secondary to the release of products of the arachidonic acid cascade and may be effectively prophylaxed in man with corticosteroids or long plasma half-life cyclooxygenase inhibitors.
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PMID:Characterization and mechanism of side-effects of Oxygent HT (highly concentrated fluorocarbon emulsion) in swine. 784 64

The use of pharmacologic stress testing for detecting and assessing ischemic heart disease (IHD) is reviewed. Methods of diagnosing IHD are designed to emulate conditions that increase myocardial oxygen demand in order to identify areas of ischemia and atherosclerotic lesions and to evaluate their functional or anatomical importance. Diagnostic methods can be divided into functional assessment with stress testing and anatomical assessment with coronary angiography. Physical stressors, such as exercise or atrial pacing, or pharmacologic stressors, such as vasodilators or beta-adrenergic-receptor agonists, can be used in stress testing. Electrocardiography, thallium planar scintigraphy, echocardiography, and other techniques are used to evaluate the response to stress testing. Unlike exercise stress testing, pharmacologic testing does not require physical exertion. Adenosine, dipyridamole, and dobutamine are the principal agents used in pharmacologic stress testing. Adenosine and dipyridamole mediate coronary artery vasodilation. Adenosine, a direct agonist, has a rapid onset and short duration of action. Dipyridamole, the only agent with approved labeling for use in stress testing, inhibits adenosine indirectly. Dobutamine increases cardiac output and heart rate as well as promoting coronary artery vasodilation. Clinical trials show that all three drugs can be used safely and effectively in patients after acute myocardial infarction or before vascular surgery and in individuals with risk factors for or symptoms of IHD. The sensitivity and specificity of pharmacologic stress testing for detecting IHD are at least as high as those of exercise testing. Minor adverse effects, including chest pain, headache, and facial flushing, are common, but major adverse effects are rare. Pharmacologic stress testing can be used in patients who cannot undergo exercise testing and offers a noninvasive alternative to coronary angiography.
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PMID:Pharmacologic stress testing: experience with dipyridamole, adenosine, and dobutamine. 816 Jun 85

A case of the inspired PCO2 increase secondary to the malfunction of expiratory valve due to a defected edge of creator is presented. In this case, we could not detect the malfunction of expiratory valve using the preanesthetic routine leak test but found it by observing the expiratory phase of the capnometric curve. Therefore, we devised a new leak test for checking the malfunction of inspiratory and expiratory valves. This test is simple and effective. The test consists of the following procedures.: 1. Connecting yokes to the oxygen piping system. 2. Connecting the breathing bag. 3. Occluding the inspiratory terminal. Closing the semiclosed valve completely. 4. Flushing the O2 gas and increasing the pressure of breathing circuit to 30 cmH2O. 5. Monitoring the pressure gauge of the anesthesia system. If the function of valves is normal, the system pressure decreases slowly. If either of the valves works wrong, it decreases rapidly. We checked anesthesia machines in our facilities using the new leak test, and found some cases of the expiratory valve malfunctions.
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PMID:[A new leak test of anesthetic machine]. 823 Jul 31

A new tonometry system for continuous and synchronous measurement of tissue oxygen- and carbon dioxide tension is described and characterized in vitro. The tonometer system consists of an O2 and CO2 permeable silicone tube continuously flushed with isotonic saline by an injection pump. When the saline passes through the tonometer tube it equilibrates with O2 and CO2 outside the tube. The oxygen- and carbon dioxide tension of the flushing solution after passage of the tonometer tube are measured by a transcutaneous combined oxygen/carbon dioxide electrode (E5280 Radiometer A/S, Copenhagen, Denmark), connected to the tonometer tube via an airtight polycarbonate chamber. In order to characterize the tonometer system in vitro the tonometer tube was submerged in a test chamber containing isotonic saline, 33 degrees C to 41 degrees C, with varying partial pressures of O2 and CO2. For various lengths of the tonometer and flushing rates through the tonometer the partial pressures of oxygen and carbon dioxide in the flushing solution (pO2eq and pCO2eq), after passage through the tonometer were recorded and compared to the known partial pressures of oxygen and carbon dioxide in the test chamber solution (pO2 test and pCO2test). PO2eq and pCO2eq approached pO2test and pCO2test, when the length of the tonometer was increased, and the flushing rate through the tonometer was decreased. The relative differences (D) between pO2eq and pCO2eq at the one hand and pO2test and pCO2test at the other hand were calculated, and equilibration curves were constructed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:An in vitro characterization of a silicone tonometer system for synchronous measurement of tissue oxygen- and carbon dioxide tension. 837 34

A thin-layer gas-solution microcalorimeter has been developed to study the binding reactions of gaseous ligands with ligand binding macromolecules in solution. Gas partial pressures are accurately changed logarithmically by means of a precision dilution valve allowing for the stepwise determination of reaction heats. Heat binding curves are constructed in which the enthalpy per mole of reaction site is plotted versus the logarithm of the ligand activity. MicroJoule sensitivity is achieved through closed loop proportion computer control and precisely twinned highly isolated sample and reference geometry. The sample, typically 50 microliters and 1 to 4 mM heme protein, is placed on a filter paper membrane which acts as a matrix of support. This orientation allows for the rapid equilibrium of reacting ligand in approximately 10 min while not significantly altering the ligand activity. The system is controlled by computer measuring the heat of reaction as the partial pressure is changed automatically, typically by flushing the system with reacting ligand then reducing its partial pressure logarithmically with a nonreacting gas such as nitrogen. Binding curves can be constructed with as little as 20 nmol of oxygen binding sites.
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PMID:A thin-layer gas-solution microcalorimeter for the determination of heat binding curves. 846 49

In rat models of liver preservation, the primary event leading to liver graft failure after cold storage is a reperfusion injury causing damage to sinusoidal endothelial cells and activation of Kupffer cells (KC). After storage for longer than 16 h in University of Wisconsin solution, reperfusion induces rapid endothelial cell killing. Kupffer cell activation also occurs as indicated by cell surface ruffling, degranulation, release of hydrolytic enzymes, generation of oxygen radicals, and increased phagocytosis. Down-regulation of KC activity with nisoldipine or pentoxifylline improves graft survival. Moreover, pretreatment of donors with small amounts of endotoxin to activate KC causes a drastic reduction of graft survival. Together, KC activation and endothelial damage cause marked microcirculatory disturbances after transplantation characterized by reduced and uneven blood flow and increased leucocyte and platelet adhesion. Such events culminate in inflammation, necrosis and fulminant graft failure. Modification of reperfusion conditions can reduce the extent of injury. In particular, flushing livers with Carolina rinse solution (CRS) at the end of storage reduces endothelial cell killing, suppresses KC activation, improves the microcirculation, and increases graft survival. Active ingredients in CRS include antioxidants (allopurinol, desferrioxamine and glutathione), adenosine and slightly acidic pH (6.5). Other potentially important ingredients are nicardipine, a calcium channel blocker, and fructose, glucose and insulin to promote glycolysis. The cytoprotective amino acid, glycine, further improves the performance of Carolina rinse solution. Reperfusion-induced changes to nonparenchymal cells play an essential role in damage to livers preserved for transplantation surgery. Understanding the role of sinusoidal endothelial cells and KC in this injury has led to promising new strategies to prolong organ storage and reduce graft failure.
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PMID:Dual role of Kupffer cell activation and endothelial cell damage in reperfusion injury to livers stored for transplantation surgery. 858 53

In this study we have determined the mutation spectrum in the complete episomal lacI gene of Escherichia coli induced by gamma-radiation under oxic conditions. Mutants were generated by 60Co gamma-irradiation of an E. coli culture of stationary cells in LB medium, under continuous flushing with oxygen. Oligonucleotide probe analysis showed that 14% of the gamma-ray-induced mutations were located at the lacI gene hot spot at position 620-632, which is characterized by a triple repeat of the 5'-TGGC-3' sequence. Previously it was shown that about 70% of the spontaneous mutations were located at this site due to the loss or the addition of a TGGC sequence. The non-hot spot mutations were further characterized by automated sequence analysis. The results show that base pair (bp) substitutions were the main type of gamma-ray-induced mutations. Although all types of bp substitutions were observed, 74% of the bp substitutions involved C/G base pairs. C/G --> T/A and C/G --> A/T substitutions were predominant, both accounting for 35% of all bp substitutions, whereas A/T --> C/G substitutions were only seldomly observed (3%). A relatively large amount of -1 bp deletions (15% of all mutations) was detected in the gamma-ray-induced mutation spectrum, mainly affecting C/G base pairs, and 10% were deletions, ranging in size from 11 to 532 bp. It can be concluded that under oxic conditions gamma-radiation induces in E. coli mainly bp substitutions of all types but preferentially at C/G base pairs, and that the mutations tend to be randomly distributed within the lacI gene sequence.
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PMID:Gamma-radiation-induced mutation spectrum in the episomal lacI gene of Escherichia coli under oxic conditions. 860 Mar 54

Although patients with COPD often have elevated pulmonary artery pressures (PAP) and pulmonary vascular resistance (PVR), it is uncertain whether treatment of this pulmonary hypertension is beneficial. We evaluated the extent of pulmonary hypertension in 16 patients with severe COPD complicated by acute respiratory failure and pulmonary hypertension. We assessed the hypothesis that the vasodilator prostacyclin (PGI2) would reduce PVR and improve systemic O2 transport. Patients with a COPD exacerbation requiring mechanical ventilation, and mean PAP greater than 30 mm Hg, were randomized to receive PGI2 or placebo, in addition to conventional therapy. Randomization to PGI2 or placebo therapy occurred 1 to 12 h after intubation, while the patient was mechanically ventilated. An optimal PGI2 dose (2 to 12 ng/kg/min, IV) was established in an initial dose-ranging study and then this dose was infused continuously for 48 h. PGI2 initially reduced PVR, but this effect dissipated within 24 h, indicating the development of tachyphylaxis. Tolerance to the adverse effects of PGI2 (tachycardia, hypotension, flushing, and headache) also developed over time. PGI2 treatment was associated with a significant fall in PaO2 but no increase in systemic oxygen transport. PGI2 proved to be a nonselective vasodilator that caused mild hypoxemia. Despite acute respiratory failure, pulmonary hypertension is mild in patients with severe COPD receiving mechanical ventilation and IV PGI2 is not beneficial in such patients.
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PMID:A placebo-controlled trial of prostacyclin in acute respiratory failure in COPD. 861 59

The stability of a preservative-free morphine chloride solution for intravenous or intrathecal use manufactured at a concentration of 40 mg/ml, near the solubility limit in water, was studied. The influence of heat and oxygen on morphine content was measured with and without autoclaving, and after additional thermal and oxidative stress. The morphine injection was stable during steam sterilization at 121 degrees C for up to 180 min if the solution was adjusted to a pH of 3.2 and if oxygen was eliminated by saturating the solution and flushing the vial with nitrogen before sealing. By adding an oxidizing agent (200 microliters H2O2 3% per 20 ml vial) before 15 min of sterilization, a decomposition of approximately 20% of morphine resulted when compared to oxygen-free control samples (P < 0.01, n = 3) High-performance liquid chromatography with UV detection (HPLC) and direct UV spectroscopy (UV) (the latter available in most hospital pharmacies for analytical purposes) were compared for specificity, precision and appropriateness for content and stability assessment of morphine solutions. UV could only be used for quantification of undecomposed morphine. Morphine degradation products of stressed solutions interfered with the direct UV assay of morphine at 286 nm, whereas these interfering components were separated by the ion-pair reversed-phase HPLC used. The results demonstrate that even in the absence of stabilizers, morphine chloride solutions may safely be sterilized for 15 min at 121 degrees C. The HPLC method was shown to be sufficiently sensitive and specific for quality control and stability assessment of morphine preparations, and, therefore, appropriate for the validation of the manufacture of morphine injection solutions in hospital pharmacies, where morphine solutions are manufactured in special strengths and volumes for individual patients' needs.
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PMID:Stability of high-dose morphine chloride injection upon heat sterilization: comparison of UV-spectroscopy and HPLC. 880 42

The extent of mesenteric infarctions caused by intestinal circulation disorders essentially depends on reactive vasoconstriction and oxygen radical induced lesions of enteric mucosa. Animal experiments indicated protective effects of an intraarterial flushing perfusion of mesenteric arteries with vasodilators and anti-oxidants. We carried out a transaortic perfusion of the superior mesenteric artery with lactated Ringer's-solution and vasodilators (papaverin, tolazolin, PGE1) in acute occlusion of mesenteric arteries in 12 patients (case reports). Three patients were treated successfully without reconstruction by conservative method alone. Only one patient (8.33%) died because of uncontrolled enteric ischemia. Angiological therapy is necessary in modern treatment of acute mesenteric ischemia. Surgical goals are elimination of central vascular occlusions and resection of necrobiotic areas of intestinal organs.
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PMID:[Perioperative intra-arterial irrigation perfusion for adjuvant therapy of acute intestinal circulatory disorders]. 885 43


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