Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An anaphylactic reaction in the isolated perfused heart is characterized by a drastic coronary constriction, arrhythmias, and an impairment of contractility. In vivo anaphylaxis is associated with respiratory distress and cardiovascular failure. The present investigation was designed to ascertain the electrocardiographic and cardiovascular changes during systemic hypersensitivity reactions. In addition, an attempt was made to differentiate cardiac from respiratory events. In guinea pigs, sensitization was produced by s.c. administration of ovalbumin together with Freund's adjuvant solution. Fourteen days after sensitization, the effects of an i.v. infusion of ovalbumin were tested in the anesthetized guinea pigs, which were ventilated with room air or 100% oxygen. A second administration of the antigen induced the development of cardiovascular collapse, leading to death within 12 min. Within 3 min, cardiac output decreased by 90% and end-diastolic left ventricular pressure increased significantly, indicating left ventricular pump failure. In the same time range, ECG recordings uniformly showed signs of acute myocardial ischemia. In addition, arrhythmias occurred in the form of atrioventricular block. Left ventricular contractility declined continuously within the first 4 min. Finally, after 4 min, blood pressure steadily decreased. During ventilation with room air, severe hypoxia developed, with arterial PO2 decreasing from 94 mmHg to 14 mmHg after 3 min. However, under ventilation with 100% oxygen, a dissociation between cardiac damage and respiratory distress occurred. Myocardial ischemia and signs of cardiac failure preceded the development of hypoxia by a significant time interval. It is to be concluded that cardiac damage is a primary event in anaphylactic shock. Furthermore, the electrocardiographic signs of ischemia are interpreted as a result of coronary artery spasm.
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PMID:Systemic anaphylaxis--separation of cardiac reactions from respiratory and peripheral vascular events. 221 74

The platelet activating factor (PAF), a low molecular phospholipid, plays an important role in inflammation, anaphylaxis, and shock state development. In the isolated perfused guinea pig heart, PAF induces a decrease in coronary flow and cardiac contractility and atrioventricular conduction disturbances. Furthermore, PAF mediates a powerful bronchoconstrictory action causing a severe impairment in respiratory function. In the present study an attempt was made to separate cardiac from respiratory events during PAF-induced shock in vivo. PAF was injected intravenously (0.1-10 micrograms/kg) into anesthetized guinea pigs ventilated with room air or 100% oxygen. Administration of 10 micrograms/kg PAF was uniformly lethal: already within 2 min, cardiac output decreased by 60% and end-diastolic left ventricular pressure increased markedly indicating cardiac failure. ECG recordings showed signs of acute myocardial ischemia. Arrhythmias occurred in terms of atrioventricular conduction delay. Blood pressure initially increased, then declined continuously to below baseline within 10 min. All animals died within 25 min. Ventilation with room air was paralleled by development of severe hypoxia. However, under ventilation with 100% oxygen a dissociation between PAF-mediated cardiac and respiratory effects occurred. It is concluded that the PAF-induced shock is primarily based on direct cardiac damage. Furthermore, the ECG signs of ischemia are most likely due to coronary spasms.
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PMID:Cardiovascular reactions and respiratory events during platelet activating factor-induced shock. 238 16

Initial cardiac failure in anaphylactoid shock is rare, classically related to cardiac anaphylaxis occurring in a highly sensitized patient. However, this anaphylaxis is not always found; the case described here of a histamine shock with ventricular fibrillation after the injection of thiopentone is a good example of this. The severity of the shock may be explained by the presence of a prolapse of the small flap of the mitral valve.
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PMID:[Mitral valve prolapse: a factor exacerbating peranesthetic anaphylactic shock]. 377 55

A 64 year-old man developed life-threatening anaphylactoid reaction caused by povidone-iodine during induction of anesthesia for elective coronary artery bypass graft surgery. While he had a history of cardiac arrest caused by iodine, he could tolerate contrast material and povidone-iodine for pre-operative coronary angiography with pretreatment of H1 and H2 receptor blockades and methylprednisolone. During the operation and postoperative care we could manage cardiac failure by continuous monitoring of cardiac output (CCO) using pulsed-thermodilution method. We recommend prophylactic use of H1 and H2 receptor blockades for surgical patients who may be at risk for anaphylaxis or anaphylactoid reaction.
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PMID:[A case of life-threatening anaphylactoid reaction caused by povidone-iodine]. 902 92

Besides acute bronchial asthma IgE-mediated anaphylaxis is certainly the most important allergological emergency. Anaphylaxis is most often caused by drugs, foods and insect stings. The most relevant pathogenetic factors induced by allergy mediators are hypovolemia, bronchial obstruction and cardiac failure. Emergency treatment consists in intramuscular application of adrenaline and volume substitution by intravenous infusion. All patients should be hospitalized immediately and treated on an intensive care unit. Unfortunately, the subsequent consultation with an allergist does often not take place. This important preventive measure includes supply of instruction for allergen avoidance and of emergency medications. In anaphylaxis induced by insect stings specific immunotherapy should be started.
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PMID:[Severe allergic-immunologic reactions]. 914 93

Recently, spinal cord stimulation (SCS) has been used for the treatment of patients in prolonged coma. However, the results of SCS in unresponsive patients with hypoxic encephalopathy at the chronic stage have not been satisfactory. Considering these circumstances, we began SCS from one month after the onset of hypoxic encephalopathy and evaluated its effect. Twelve patients (5 males and 7 females) with hypoxic encephalopathy, ranging in age from 7 to 72 years, were treated with SCS. The causes of hypoxia were acute cardiac failure in 4, automobile exhaust gas poisoning in 2, and asthma, pneumothorax, anaphylaxis, asphyxia, drowning and hypotension during aortic surgery in one patient each. One month after the onset, an electrode for electrical stimulation was implanted in the epidural space at the C2-C4 level under general anesthesia. The spinal cord was stimulated for 8 hours each day, starting on the day after implantation, and was continued for 3 months. Magnetic resonance imaging (MRI), cerebral blood flow (CBF) measurement using xenon-computed tomography (Xe-CT), and measurement of auditory evoked potential (AEP) and somatosensory evoked potential (SEP) were carried out 3 weeks after the onset for presurgical evaluation. Among the 12 patients, 7 (58%) showed clinical improvement, beginning within two weeks after starting stimulation. They were able to communicate with others and to express their emotion. However, disturbance of writing, picture drawing and calculation were not improved by stimulation. From presurgical evaluation, cases in which SCS therapy was effective had the following features: 1) No hemorrhagic infarction in the basal ganglia was demonstrable by MRI. 2) Mean hemispheric CBF measured by the Xe-CT method exceeded 25 ml/100 g per min. 3) The mean increase in hemispheric CBF 20 min after acetazolamide administration exceeded 5 ml/100 g per min. 4) An N20 peak was evident on the median nerve SEP, SCS appears to be an effective supplementary for unresponsive patients with hypoxic encephalopathy at the subacute stage, in addition to rehabilitation and drug therapy.
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PMID:[Spinal cord stimulation therapy at an early stage for unresponsive patients with hypoxic encephalopathy]. 959 12

On any given day a patient seen by the dental hygienist has the potential of experiencing a life-threatening medical emergency. All dental hygiene practitioners should be aware of potential risks that a patient may present, take steps to prevent life-threatening events from occurring, and plan for problems in advance of their happening. The primary goal of this course is to help dental hygienists carry out the ethical, moral, legal, and professional obligation owed any patient. The course will review the basics of medical emergencies, with particular emphasis on those that are most likely to occur in the dental office. Discussion will center on general aspects of prevention and preparation, and will focus on the recognition and emergency treatment of specific conditions. Vasodepressor syncope, orthostatic hypotension, acute adrenal insufficiency, hyperventilation, asthma, heart failure and acute pulmonary edema, cerebrovascular accident seizures, hyperglycemia, hypoglycemia, myocardial infarction, angina pectoris, and anaphylaxis will be emphasized.
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PMID:Medical emergencies in the oral health care setting. 1131 57

Bradykinin is formed by the interaction of factor XII, prekallikrein, and high-molecular-weight kininogen on negatively charged inorganic surfaces (silicates, urate, and pyrophosphate) or macromolecular organic surfaces (heparin, other mucopolysaccharides, and sulfatides) or on assembly along the surface of cells. Catalysis along the cell surface requires zinc-dependent binding of factor XII and high-molecular-weight kininogen to proteins, such as the receptor for the globular heads of the C1q subcomponent of complement, cytokeratin 1, and urokinase plasminogen activator receptor. These 3 proteins complex together within the cell membrane, and initiation depends on autoactivation of factor XII on binding to gC1qR (the receptor for the globular heads of the C1q subcomponent of complement). There is also a factor XII-independent bypass mechanism requiring a cell-derived cofactor or protease that activates prekallikrein. Bradykinin is degraded by carboxypeptidase N and angiotensin-converting enzyme. Angioedema that is bradykinin dependent results from hereditary or acquired C1 inhibitor deficiencies or use of angiotensin-converting enzyme inhibitors to treat hypertension, heart failure, diabetes, or scleroderma. The role for bradykinin in allergic rhinitis, asthma, and anaphylaxis is to contribute to tissue hyperresponsiveness, local inflammation, and hypotension. Activation of the plasma cascade occurs as a result of heparin release and endothelial-cell activation and as a secondary event caused by other pathways of inflammation.
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PMID:Pathways for bradykinin formation and inflammatory disease. 1184 87

Cardiac mast cells proliferate in cardiovascular diseases. In myocardial ischemia, mast cell mediators contribute to coronary vasoconstriction, arrhythmias, leukocyte recruitment, and tissue injury and repair. Arrhythmic dysfunction, coronary vasoconstriction, and contractile failure are also characteristic of cardiac anaphylaxis. In coronary atherosclerosis, mast cell mediators facilitate cholesterol accumulation and plaque destabilization. In cardiac failure, mast cell chymase causes myocyte apoptosis and fibroblast proliferation, leading to ventricular dysfunction. Chymase and tryptase also contribute to fibrosis in cardiomyopathies and myocarditis. In addition, mast cell tumor necrosis factor-alpha promotes myocardial remodeling. Cardiac remodeling and hypertrophy in end-stage hypertension are also induced by mast cell mediators and proteases. We recently discovered that cardiac mast cells contain and release renin, which initiates local angiotensin formation. Angiotensin causes coronary vasoconstriction, arrhythmias, fibrosis, apoptosis, and endothelin release, all demonstrated mechanisms of mast-cell-associated cardiac disease. The effects of angiotensin are further amplified by the release of norepinephrine from cardiac sympathetic nerves. Our discovery of renin in cardiac mast cells and its release in pathophysiological conditions uncovers an important new pathway in the development of mast-cell-associated heart diseases. Several steps in this novel pathway may constitute future therapeutic targets.
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PMID:Renin: at the heart of the mast cell. 1749 56

In our institution, we introduced a screen-based simulator to our undergraduate lectures on medical crisis management. We hypothesised that this novel use of the screen-based simulator would be as effective as our conventional lectures. To test this we randomly divided medical students into two groups. Students in Group A were taught medical crisis management (heart failure and anaphylaxis) using a screen-based simulation program projected onto a shared screen, with a facilitator guiding the students through the scenarios. Simultaneously, students in Group B were lectured the same content without the screen-based simulation. Both groups were allotted exactly one hour Several days later, students were tested on their management of anaphylaxis using the Human Patient Simulator. A blinded marker assessed them on diagnosis, resuscitation, specific treatment, call for help and for reassessment of the patient. Students also answered a questionnaire on their experience. Sixty-four students participated in the study. Both groups had similar overall scores. However students in Group A scored better in the specific treatment category by a factor of 1.7. Students in both groups rated their learning experiences highly. This study showed that screen-based simulation was as effective as conventional lectures and might be even more effective in some areas.
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PMID:A comparison of screen-based simulation and conventional lectures for undergraduate teaching of crisis management. 1871 27


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