Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
 ...
PMID:[Emergencies in angiology]. 849 73

Sudden occlusion of a peripheral artery by embolization or acute thrombosis results in acute ischemia. This is most commonly associated with sudden onset of severe pain, numbness and pallor. Chronic ischemia from peripheral vascular disease results in intermittent claudication. We present a case of peripheral embolization from a left ventricular aneurysm in a previously asymptomatic male who presented to the emergency department complaining of two weeks of pain in his left great toe. Included in the discussion are important diagnostic tests for peripheral thromboembolism and ventricular aneurysm as well as suggestions for emergency department management.
 ...
PMID:Left ventricular aneurysm and peripheral embolism as cause of atypical foot pain. 943 78

Cerebral microcirculation has a series of complex relationships with arterial hypertension determined, on one hand, by the size and the location of the vessels involved, and on the other hand, by the chronic or acute nature of the hypertension. The small arterial vessels of the cerebral parenchyma react to the effects of chronic hypertension with irreversible structural changes, whose pathologic and radiological correlation is chronic ischemia of the white substance, shown by paleness of the white substance, together with small lacunar infarctions, with a clinical association of dementia, motor disorders and pseudo-bulbar syndrome. With the appearance of an acute rise in arterial pressure, these vessels react with generally reversible changes which lead to an increase in the permeability of the hematoencephalic barrier with formation of cerebral edema and a clinical association generally demonstrating the focal nature of the vascular abnormality (such as in hypertensive encephalopathy with changes in posterior hemispheric predominance) or its unilateral location in cases in which the process occurs in one of the carotid territories (post-endarterectomy).
 ...
PMID:[Hypertensive vascular disease and cerebral microcirculation]. 1037 57

Two types of sinus nodal cells were responsible for the main differences in the literature concerning the ultrastructure of the sinuatrial node: the intercalated clear cells and pale cells. Canine hearts were arrested by (1) aortic cross clamping, (2) coronary perfusion with the cardioplegic solution St. Thomas, and (3) coronary perfusion with the cardioplegic solution HTK (Custodiol(R)). After fixation by immersion or perfusion the sinus node tissue was prepared for electron microscopy. Following cardioplegic arrest and perfusion fixation, three nodal cell types in the non-ischemic sinuatrial node were observed: typical nodal cells, transitional cells, and intercalated clear cells. Less than 1% of the non-ischemic sinuatrial cells were intercalated clear cells, surrounded by typical nodal cells or transitional cells. The contractile apparatus of the intercalated clear cells was extremely poorly developed. Great structural variations in the mitochondria were observed in intercalated clear cells, variations that would not appear under conditions of ischemia. In contrast, after 15-25 min of ischemia at 25 degrees C the appearance of the sinus nodal cells was strikingly different from that of the non-ischemic sinuatrial cells. More than 10% of the nodal cells showed typical ischemic alterations, e.g., mitochondrial swelling, clumping of nuclear chromatin, loss of glycogen particles, and cell swelling in varying degrees. Because they look very pale, these nodal cells have been described as pale cells in the literature. Intercalated clear cells appear mainly in non-ischemic nodal tissue. Pale cells are ischemically damaged sinus nodal cells.
 ...
PMID:Intercalated clear cells or pale cells in the sinus node of canine hearts? An ultrastructural study. 1096 34

Apoptosis has been implicated recently as a prominent response of the brain to a variety of insults, such as ischemia and trauma. In this study, we demonstrate that apoptosis is a prominent part of the brain's response to a thermal insult. To examine the brain's response to a thermal insult, a new model of thermal brain injury in the laboratory rat was developed. Water heated to 60 degrees C was passed over an area of thinned calvarium for 1 min. This resulted in an actual brain temperature of 47-48 degrees C. A uniform area of 2,3,5-triphenyl-tetrazolium chloride pallor was demonstrated and pyknotic neurons were seen in the area of injury by hematoxylin-eosin staining. Apoptosis was demonstrated by the characteristic DNA fragmentation seen by agarose gel electrophoresis, ApopTag in situ staining and electron microscopy. The findings of apoptosis were localized to the area of thermal injury and were time dependent, starting 6 h after the insult and peaking approximately 18 h after the insult. This represents one of the first demonstrations that apoptosis occurs in the brain in response to a thermal injury.
 ...
PMID:Apoptosis occurs in a new model of thermal brain injury. 1106 Apr 94

The white matter lesions in dementia of Alzheimer type (DAT) with and without multiple lacunar infarctions were studied relative to a normal control group. The frequency and distribution of white matter (WM) lesions in DAT (22 cases; mean age +/- standard deviation (SD), 88.1 +/- 5.8), DAT with multiple lacunar infarctions (DAT + CVD, 18 cases; mean age +/- SD, 87.8 +/- 6.0), and in a normal control group (17 cases; mean age +/- SD, 85.2 +/- 4.8) were evaluated. The frequency of myelin pallor (frontal, parietal and occipital lobes) was significantly higher in the DAT + CVD group than in the other groups (DAT and controls). There was no significant difference in the frequency of myelin pallor between the DAT and control groups. Therefore, it was concluded that the WM lesions in DAT are the result of ischemia rather than wallerian degeneration.
 ...
PMID:Dementia of Alzheimer type with and without multiple lacunar infarctions: evaluation of white matter lesions. 1113 36

The history and physical examination are extremely important in the management of vascular surgical patients because a correct diagnosis can usually be made on the basis of information obtained from these two modalities. The severity of the chronic occlusive process leads to characteristic symptoms in the extremity: claudication, rest pain, skin ulcerations and gangrene. Chronic progressive lesions permit enlargement of collateral blood supply which, for a time, minimizes the severity of symptoms. Milde degrees of arterial insufficiency (claudication) can be treated conservatively. Unreconstructed chronic critical ischemia predicts a poor outcome in terms of survival and limb salvage. The outlook with arterial reconstructive surgery is by far better. Arteriography ist the most reliable diagnostic test for occlusive lesions. It ist essential for the operative planning. Vein-bypass procedures are, if feasible, very effective in most cases. Acute embolic occlusion: Sudden occlusion of a previously patent artery is usually a dramatic event producing severe ischemia of the distal tissue. The characteristic symptoms and signs are the 5 P's: pallor, pain, paresthesia, paralysis, pulselessness. Emergent restoration of blood flow by operation may be essential to prevent limb loss. Milder forms of ischemia (acute thrombosis--acute or chronic disease) can be treated initially with intravenous heparin if the extremity is not threatened (minimal sensory loss, no muscle weakness). Elective surgery at a later date is highly successful.
 ...
PMID:[Surgical therapy of acute and chronic arterial occlusions below the inguinal ligament]. 1121 71

A 41-year-old woman presented to the Emergency Department complaining of a 4-day history of worsening lower leg pain, pallor, and a sensation of coolness aggravated by exertion. Evaluation revealed severe lower extremity vasospasm. She recently had been prescribed clarithromycin for "flu-like" symptoms, and for many years had been taking a caffeine-ergotamine preparation for migraine headaches. Clarithromycin is known to interfere with ergotamine metabolism. This drug interaction is often not recognized. Ergot alkaloids are commonly used for migraine headaches and have vasoconstrictive properties. In a patient with ergotamine toxicity, these vasoconstrictive properties can lead to frank ischemia. We reviewed the literature for reports of ergotamine-associated ischemia and for reports of ergotamine toxicity caused by drug-drug interaction.
 ...
PMID:An unusual case of clarithromycin associated ergotism. 1172 70

A 52-year-old man had loss of vision and black discoloration of the lids of the right eye after a retrobulbar injection of 3 mL lidocaine hydrochloride 2% (Xylocaine). Examination of the right eye revealed no light perception with extensive necrosis of the lids. Anterior segment examination revealed conjunctival pallor, corneal edema, and necrosis of the sclera. This is a previously unreported complication of retrobulbar anesthesia comprising ophthalmic artery occlusion with scleral melt, ocular ischemia, and eyelid necrosis.
 ...
PMID:Necrosis of the eyelids and sclera after retrobulbar anesthesia. 1268 60

Direct arterial blood pressure monitoring via the radial artery is a relatively common method employed during the perioperative period. Complications attributed to radial artery catheterization are extremely rare but can include thrombosis, ischemia, infection, and aneurysm formation at the site of catheter insertion. This report describes an episode of hand ischemia in a pediatric patient. The patient experienced a brief period of hypotension secondary to blood loss. A pallor hand was noticed after the patient had been adequately resuscitated. Appropriate treatment was administered, and the patient was eventually discharged to home without any further complications.
 ...
PMID:Hand ischemia associated with profound hypotension and radial artery catheterization in a pediatric patient: a case report. 1277 49


<< Previous 1 2 3 4 5 6 7 Next >>