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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The accumulation of endogenous catecholamines within the extracellular space of the ischemic myocardium has been studied in the isolated perfused (Langendorff) heart of the rat subjected to various periods of complete ischemia, with subsequent collection of the reperfusate. Catecholamines and deaminated metabolites were measured by radioenzymatic methods, or high pressure liquid chromatography. Ischemic periods of less than 10 minutes are not associated with an increased overflow of catecholamines or metabolites. Longer periods of ischemia are accompanied by the overflow of noradrenaline and its deaminated metabolite 3,4-dihydroxyphenylglycol. This overflow increases with lengthening of the preceding ischemic period (10 minutes: 2.5 +/- 0.6, 20 minutes: 209.8 +/- 17.2, 60 minutes: 1270.5 +/- 148.1 pmol noradrenaline/g heart). Noradrenaline concentration is highest during the first minute of reperfusion, suggesting that the noradrenaline detected during reperfusion is released into the extracellular space of the myocardium during ischemia and is subsequently eluted. Experiments with variation of extracellular calcium concentration and with neuronal uptake (uptake1) blocking agents suggest that different mechanisms of catecholamine release are acting during the course of ischemia. A calcium-independent carrier-mediated efflux of noradrenaline from the nerve terminals is of major importance, using the same carrier as is normally responsible for transporting noradrenaline from the synaptic clefts into the neuronal varicosities. Thus, various uptake1-blocking agents diminish the noradrenaline overflow following ischemic periods of between 10 and 40 minutes. The noradrenaline overflow following longer periods of ischemia is unaffected by uptake1-blocking agents, and additional noradrenaline release at this time is probably consequent upon dissolution of cell membranes. Overflow of adrenaline and dopamine occurs to a minor degree (less than 5% of the corresponding noradrenaline overflow), and only after ischemic periods of more than 15 minutes.
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PMID:Release of endogenous catecholamines in the ischemic myocardium of the rat. Part A: Locally mediated release. 648 89

Coronary artery aneurysm was demonstrated in 7 patients, whose ages ranged from 38 to 66 years, by selective coronary angiography. Four patients had atypical chest pain probably not caused by cardiac ischemia, 1 patient had aortic stenosis and recurrent bouts of atrial fibrillation, and 2 were evaluated following myocardial infarction and found to have triple vessel atherosclerotic coronary disease. Mitral valve prolapse and varicosities of the coronary venous tree found in one individual suggest that mucoid degeneration which replaces the normal fibrous tissue resulting in weakness of vessel wall may be responsible for the formation of coronary artery aneurysm and varicosities of the coronary venous system. The unsuspected presentation and benign course of these patients are emphasized and the pertinent literature is reviewed.
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PMID:Coronary artery aneurysms. Report of seven cases and review of the pertinent literature. 737 59

We report our findings in the guinea pig involving dopamine in postsynaptic regulation of the activity of glutamatergic inner hair cells (IHCs) and in protection of primary auditory neurons during transient ischemia. Seven days after intracochlear perfusion of 6-hydroxydopamine, no immunoreactivity to tyrosine hydroxylase (TH) was demonstrable within the organ of Corti. TH and aromatic amino acid decarboxylase were immunolocalized at an ultrastructural level within lateral olivocochlear varicosities synapsing with radial auditory dendrites postsynaptic to the IHCs. The D2 agonist piribedil induced a dose-dependent decrease in the amplitude of the compound action potential of the auditory nerve. Piribedil also prevented appearance of ischemia-induced swelling of the radial dendrites.
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PMID:Synaptic connections and putative functions of the dopaminergic innervation of the guinea pig cochlea. 757 83

Color Doppler imaging of the orbit shows promise in evaluation of several types of orbital abnormalities. The most promising use is for evaluation of vascular disorders. Screening for orbital varices and cavernous-carotid fistulas is easily accomplished. Color Doppler imaging can also be useful in diagnosis of ocular ischemia, central retinal vessel occlusion, and anterior ischemic optic neuropathy. In cases of inflammatory disease, it may be helpful in searching for complications of infection and in monitoring the size of fluid collections. In cases of tumors, color Doppler imaging can be used to monitor lesion size and in surgical planning. More work needs to be done to determine the role of color Doppler imaging in evaluation of trauma and congenital abnormalities. An understanding of the basic anatomy of the orbit, examination techniques, and common disease processes in the orbit will allow the radiologist to offer this potentially valuable modality to referring clinicians.
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PMID:Color Doppler US of the orbit. 762 65

We report two patients with bleeding stomal varices following total colectomy and ileostomy. The varices were demonstrated by superior mesenteric angiography and percutaneous transhepatic mesenteric venography; dilated ileal veins drained via the stomal varices into abdominal wall veins. Bleeding from the stomal varices was treated by transhepatic embolization. The first patient required three transhepatic embolizations after recurrent bleeding due to recanalization of the embolized ileal vein and the development of collaterals from the adjacent ileal veins over a one-year period. The second patient died of respiratory failure 1 week after embolization. Neither patient developed mesenteric or stomal ischemia.
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PMID:Percutaneous transhepatic embolization as treatment for bleeding ileostomy varices. 764 95

Tamoxifen is the anti-estrogen the most widely used in breast cancer. The duration of its prescription, as adjuvant treatment, tends to increase (5 years, and even more) and now it is used in chemoprevention. A slight increase of thromboembolic complications was noted in some studies. This article evaluates the frequency of thromboembolic accidents (TEA) in 441 postmenopausal patients treated by an association of conservative radiosurgery, tamoxifen +/- chemotherapy, for a breast carcinoma T0, T1T2 < 4 cm. Nineteen patients (4.3%), all in remission, presented a TEA, between 1 and 44 months after the beginning of the tamoxifen treatment. We observed seven pulmonary embolisms (PE), 11 deep venous thromboses (DVT) and an acute arterial ischemia. Two patients aged 74 and 80 years died, the others had a favourable evolution under anticoagulant treatment. Among these 19 patients, six presented known risks factors (phlebitis, cardiovascular disorders) and ten had a "favouring circumstance" aggravating the risk of TEA (surgical operation, severe infection, fracture). Their median age was 65 years (61 for all the 441 patients). We noted eight cases of breast lobular cancer (42%) among these 19 patients (11% for all the patients). Among postmenopausal patients, the indication of tamoxifen must be evaluated according to the benefits expected in those with high risk factors of TEA (history of heart failure, obesity, spread varix, age > 65 years). In case of DVT and/or PE, this treatment seems contra-indicated. In case of "favouring circumstances", a hypocoagulant or systematic anticoagulant treatment must be proposed. In case of combined chemotherapy, it is better to start tamoxifen at the end of the treatment. These simple prophylactic measures should allow to reduce significantly the risk of TEA in postmenopausal patients with adjuvant anti-estrogenotherapy.
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PMID:[Thromboembolic accidents in postmenopausal patients with adjuvant treatment by tamoxifen. Frequency, risk factors and prevention possibilities]. 774 16

The greater saphenous veins in patients with varicose veins has been overlooked as a conduit for arterial bypass. Greater saphenous veins is often normal and when only parts of the greater saphenous veins are of normal size, a veno-venous or a graft composite bypass may be performed. The goal of this preliminary study was to asses if wrapped autologous greater saphenous veins could be suitable conduits for arterial bypass in patients presenting with critical ischemia. In three patients the greater saphenous veins had one to four dilatations which were wrapped with short segments of Polytetrafluoroethylene graft. In three other patients, the dilated area being longer, the greater saphenous veins were totally wrapped in a hand-made mesh of Dacron. No complications were due to the wrapping procedure and the unwrapped segments did not dilate during a mean three year follow-up. We conclude that wrapped autologous greater saphenous veins may help save limbs of patients with critical ischemia. As an underestimated proportion of patients presenting with varicose tributaries have normal or quite normal greater saphenous veins, the caliber of the greater saphenous veins should be carefully measured before treating the varicose veins. All greater saphenous veins suitable for an arterial bypass should be preserved remembering that one or several dilatations may be wrapped if the greater saphenous veins is used as an arterial substitute. Patients should be informed of the reasons for this choice.
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PMID:Wrapped autologous greater saphenous vein bypass for severe limb ischemia in patients with varicose veins. Preliminary report. 779 Mar 28

Morphological changes in the hepatic microvasculature were studied in experimentally induced ischemia-reperfusion injury in the rat using a vascular casting technique. Partial hepatic ischemia was induced for 90 min followed by 24 hr reperfusion. Microvascular casting was performed after 24 hr reperfusion by either intraarterial or intravenous infusion of acrylic resin (Mercox). After corrosion of the tissue, the cast was examined by scanning electron microscopy. Casts of normal livers showed good patency with no evidence of unfilled areas. The mean diameter of sinusoids was 14 +/- 3 microns with those in zone 1 slightly smaller than those in zone 3. Liver casts from rats subjected to ischemia and reperfusion resulted in gross disruption of normal architecture. The common characteristics seen in both prograde and retrograde casts were clusters of closed sinusoids around zones 2 and 3 of the liver acini, which resulted in cavities of various sizes. Varicosities were observed in some areas. The mean diameter of sinusoids in areas of patent microvascular structure (10 +/- 2 microns) was significantly smaller compared to those in normal livers (P < 0.001). Misoprostol given at 1 min before reperfusion markedly reduced the microvascular injury. The hepatic microvascular was generally intact with mild focal unfilled areas. The majority of the sinusoids were of normal size and no clusters of blind ending sinusoids were detected. The present study shows that hepatic ischemia-reperfusion results in extensive microvascular injury in the liver. The protective effects of misoprostol against this injury may occur at the vascular level.
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PMID:Microvascular changes in liver after ischemia-reperfusion injury. Protection with misoprostol. 805 Mar 17

The radiographic appearance of intestinal edema, including colonic edema, has been well described in the literature. Severe wall circumferential thickening can occur within the colon in a number of conditions. This includes edema secondary to colitis, allergy, ischemia, and infiltrative neoplastic processes. Edema may be secondary to low protein levels, as from protein losing enteropathy, nephrotic syndrome, and hepatic cirrhosis. The following case, in which there was severe ascending colonic wall thickening due to edema, is unusual in two respects: it had well-developed demonstrated "protective" right colonic varices and a normal protein level.
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PMID:CT demonstration of ascending colon varices. 818 Aug 60

Acute arterial occlusions of the extremities present with the classical five P's: pain, pallor, pulselessness, paresthesia, paresis. Loss of sensitivity and motility are symptoms of the most severe grade of ischemia. The occlusions are due to embolism in about 70% of subjects and to local thrombosis in 30%. These patients have to be treated immediately with heparin. In the mildest forms, deobliteration is desirable, but in the more severe cases rapid restoration of flow not only saves limbs but also life. Deobliteration may be performed surgically or by means of catheters (local thrombolysis or thrombus aspiration) if available. Deep vein thrombosis, the other kind of emergency situation, requires immediate anticoagulation as soon as pulmonary embolism is suspected. It should be initiated by heparin and followed by oral anticoagulation. In patients presenting without pulmonary embolism but a swollen leg, ruptured Baker cysts or muscle hematomas should be ruled out before anticoagulation is started. Systemic thrombolysis or surgical thrombectomy is reserved for young patients with acute isolated thromboses. Thrombectomy must also be kept in reserve for the most severe form of deep venous thromboses, the phlegmasia cerulea dolens. In thrombophlebitis, no anticoagulation is indicated except in bedridden patients. The others must remain mobile and may be treated by systemic and local antiinflammatory drugs, incision of thrombosed varices, and bandages.
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PMID:[Emergencies in angiology]. 849 73


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