Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0729233 (Thoracic)
 6,478 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An elevation of blood pressure is observed in approximately 30% of dialysis patients treated with recombinant human erythropoietin (rHuEPO). Various studies have been performed in order to elucidate possible underlying mechanisms, but it is not yet well understood whether there is one major mechanism involved. In this present study, samples were obtained from male normotensive Wistar-Kyoto rats (WKY) and genetically hypertensive rats (SHR) at the age of 5 and 20 weeks. Thoracic aorta rings, with or without endothelium, isolated from WKY and SHR were used to evaluate the direct effect of rHuEPO on vascular smooth muscle by measuring the tension of vascular smooth muscle induced by various concentrations (1-100 IU/ml) of rHuEPO. Also, rHuEPO (10, 100, 1000 and 10,000 IU/kg) was intravenously administrated and the changes in mean blood pressure were recorded for 5-10 min. rHuEPO produced no significant contraction in the rat aortae in any of the preparation studies, in the presence or the absence of endothelium. The intravenous administration of rHuEPO had no immediate effect on mean blood pressure in 5- and 20-week-old WKY and SHR. These results suggest that the elevation of blood pressure observed in the clinical setting following the administration of rHuEPO is not due to a direct pressor effect on vascular smooth muscle.
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PMID:Recombinant human erythropoietin has no direct or strong vasoconstrictor effects in vivo and in vitro. 756 9

The PCV of a llama increased from 50.8 to 74.0% during a 19-month period. The llama remained clinically normal unless stressed, when it would become dyspneic and tachypneic. Thoracic auscultation revealed sounds consistent with pneumonia, but were probably attributable to pulmonary congestion resulting from polycythemia. A diagnosis of secondary absolute polycythemia was made on the basis of high serum erythropoietin concentrations and no evidence of hypoxia. Necropsy revealed congestion of the lungs and liver. Cause of the polycythemia was not determined. Polycythemia should be considered as a differential diagnosis in a llama with exercise intolerance and harsh bronchovesicular sounds.
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PMID:Polycythemia in a llama. 805 Sep 79

A 2-year-old, castrated male, mixed-breed dog presented with a 1-month history of red eyes and intermittent vomiting and a 2-week history of polyuria and polydipsia. Bilateral anterior uveitis and active chorioretinitis in the left eye were found on ophthalmic examination. Complete blood counts demonstrated evidence of an increased red blood cell mass. Thoracic and abdominal radiographs, abdominal ultrasonography, and Doppler echocardiography were unremarkable. Serum erythropoietin level was low-normal, consistent with a diagnosis of polycythemia vera. Resolution of all systemic and ocular signs occurred, and remission was achieved following phlebotomy and treatment with oral hydroxyurea.
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PMID:Polycythemia vera in a dog presenting with uveitis. 1287 25

This study was designed to determine whether recombinant human erythropoietin (rHuEpo) administration increases vascular nitric oxide (NO) production in healthy rats. We hypothesized that rHuEpo hypertension is associated with increased endothelial expression of nitric oxide synthase and augmented NO-dependent vasodilation. Male rats were instrumented with pulsed Doppler flow probes around their ascending aorta and with arterial and femoral catheters. Rats were treated for 14 days with rHuEpo (2 U/d) or vehicle. rHuEpo elevated hematocrit and increased mean arterial pressure (142 +/- 3 versus 116 +/- 4 mm Hg). Thoracic aorta segments from rHuEpo rats had a modest increase in NO-dependent relaxation assessed by acetylcholine (10(-10) to 10(-5) mol/L) relaxation of phenylephrine (PE) (10(-6) mol/L) contracted arteries. Relaxation to NO-donor, s-nitrosyl acetylpenicillamine, and PE contraction were not different from control arteries. The NO synthase inhibitor, N-omega-nitro-L-arginine, increased blood pressure and total peripheral resistance more in rHuEpo rats at both 10 and 30 mg/kg. NOS expression in rHuEpo aorta and plasma NOx concentrations were increased compared with control. Thus, it appears that vascular eNOS expression is increased and causes basal vasodilation in rHuEpo hypertensive rats.
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PMID:Erythropoietin administration in vivo increases vascular nitric oxide synthase expression. 1450 39

The research activity upon erythropoiesis regulation carried out by the team in the Physiology Department and in the Institute of Medical Research of the Romanian Academy in Cluj-Napoca developed continuously after 1950. Our studies contributed to the isolation, identification and characterization of erythropoietin (Epo) and also to a better understanding of the nervous adaptation mechanisms to hypoxia. At present, it is well known that hypoxia acts upon erythropoiesis through Epo production. Direct central nervous stimulation through hypoxia induces, via a neuro-humoral mechanism, a sympatho-adrenal response and release of Epo. Adaptive polyglobulia as a response to hypoxia increases the capacity of oxygen binding and transport. In this paper we attempted to identify the role of the sympathetic nervous system in adaptation to hypoxia correlated with Epo secretion. Experiments were carried out in three groups of rats, respectively, with cervical, thoracic, and lumbar (without celiac) sympathectomy. The sympathectomized animals were submitted to hypobaric or to hemorrhagic hypoxia, in parallel with control groups. Erythrocytic parameters (red blood cells, reticulocytes, hematocrit, and haemoglobin) were repeatedly assayed during the following 2-4 weeks. The results showed that animals with cervical sympathectomy adapt in a deficient manner to hypoxia; lacking the adaptive sino-carotid reflexes, adaptation occurs through increased Epo secretion, animals with cervical sympathectomy having higher counts of reticulocytes and of red blood cells at the end of experiment than intact animals. Thoracic sympathectomy has little influence upon the erythrocytic response, as the largest part of the respiratory and circulatory sympathetic reactions occur via the cervical sympathetic nerve. Lumbar sympathectomy without removal of the celiac ganglion does not decrease the erythrocytic response as expected; on the contrary, the erythrocytic response is increased as compared to controls.
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PMID:The sympatho-adrenal response and erythropoietin production in adaptation to hypoxia. 1598 63

Preoperative antiplatelet drug use is common in patients undergoing coronary artery bypass grafting (CABG). The impact of these drugs on bleeding and blood transfusion varies. We hypothesize that review of available evidence regarding drug-related bleeding risk, underlying mechanisms of platelet dysfunction, and variations in patient response to antiplatelet drugs will aid surgeons as they assess preoperative risk and attempt to limit perioperative bleeding. The purpose of this review is to (1) examine the role that antiplatelet drugs play in excessive postoperative blood transfusion, (2) identify possible mechanisms to explain patient response to antiplatelet drugs, and (3) formulate a strategy to limit excessive blood product usage in these patients. We reviewed available published evidence regarding bleeding risk in patients taking preoperative antiplatelet drugs. In addition, we summarized our previous research into mechanisms of antiplatelet drug-related platelet dysfunction. Aspirin users have a slight but significant increase in blood product usage after CABG (0.5 U of nonautologous blood per treated patient). Platelet adenosine diphosphate (ADP) receptor inhibitors are more potent antiplatelet drugs than aspirin but have a half-life similar to aspirin, around 5 to 10 days. The American Heart Association/American College of Cardiology and the Society of Thoracic Surgeons guidelines recommend discontinuation, if possible, of ADP inhibitors 5 to 7 days before operation because of excessive bleeding risk, whereas aspirin should be continued during the entire perioperative period in most patients. Individual variability in response to aspirin and other antiplatelet drugs is common with both hyper- and hyporesponsiveness seen in 5 to 25% of patients. Use of preoperative antiplatelet drugs is a risk factor for increased perioperative bleeding and blood transfusion. Point-of-care tests can identify patients at high risk for perioperative bleeding and blood transfusion, although these tests have limitations. Available evidence suggests that multiple blood conservation techniques benefit high-risk patients taking antiplatelet drugs before operation. Guidelines for patients who take aspirin and/or thienopyridines before cardiac procedures include some or all of the following: (1) preoperative identification of high-risk patients using point-of-care testing; (2) withdrawal of aspirin or other antiplatelet drugs for a few days and delay of operation in patients at high risk for bleeding if clinical circumstances permit; (3) selective perioperative use of evidence-based blood conservation interventions (e.g., short-course erythropoietin, off-pump procedures, and use of intraoperative blood conservation techniques), especially in high-risk patients; and (4) platelet transfusions if clinical bleeding occurs.
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PMID:Antiplatelet drugs: mechanisms and risks of bleeding following cardiac operations. 2253 65