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

A brief review of the pharmacology, pharmacokinetics, and metabolism of buflomedil-HCl is presented providing a pharmacologic basis for buflomedil therapy of ischemia associated with peripheral vascular disease. Buflomedil is readily absorbed in the gastrointestinal tract and has a plasma half-life of approximately 2-3 hours. The para-desmethyl derivative of buflomedil has been identified as a urinary metabolite. Pharmacologically, buflomedil increases perfusion to impaired vascular beds of the microcirculation, increases arterial perfusion with minimal effects on central hemodynamics, exhibits apparent oxygen "sparing" effects in animal experiments, demonstrates inhibitory effects on platelet aggregation, and, in preliminary experiments, appears to improve deformability of erythrocytes with abnormal fluidity. A nonspecific alpha-receptor blocking activity appears to be involved, at least in part, in these pharmacologic effects. The relative importance of these mechanisms/effects in the treatment of symptoms of vascular disease is unknown.
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PMID:An experimental overview of a new vasoactive drug: buflomedil HCl. 703 90

The effect of chronic occlusive peripheral vascular disease (PVD) on the histochemistry and capillarity of the gastrocnemius muscle was studied in 129 biopsies taken from 93 subjects. Sixty-three patients underwent biopsy during surgical procedures, and data related to walking distance and ankle systolic pressure. Thirty biopsies taken from normal subjects post mortem served as a control group, and data were analyzed for fiber type distribution, fiber area, fiber type grouping, and fiber capillarity. Fiber type distribution did not alter significantly between the patients with PVD and the control group, but the mean fiber area of the type 1 fiber in male patients with intermittent claudication (IC) was reduced when compared to that in age-matched controls (4608 +/- 1181 mu 2, IC +/- 1 SD; 5795 +/- 1771 mu 2, controls +/- 1 SD) (P less than 0.05). When bilateral biopsies were taken from the gastrocnemii of patients with unilateral occlusions, the type 2 fibers in the diseased leg were significantly smaller than fibers of the control group (2821 +/- 953 mu 2, IC +/- 1 SD; 4318 +/- 1504 mu 2, controls +/- 1 SD) (P less than 0.02). Fiber type grouping, evidence of denervation and reinnervation of muscle, appeared to be more common in patients with more severe limb ischemia. Overall capillary numbers did not appear to alter with degree of ischemia, but fiber shrinkage appeared to compensate for any loss of capillaries in the more ischemic muscle. These data suggest that the limb of the untrained patient with IC does not adapt to ischemia by adjusting its exercise capacity but merely shows evidence of disuse. These adaptations suggest that there may be much to be gained by nonsurgical methods of treating IC.
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PMID:Ultrastructural and capillary adaptation of gastrocnemius muscle to occlusive peripheral vascular disease. 710 Nov 34

Limb ischemia due to blunt trauma, dissecting hematoma, and cardiac dysfunction jeopardizes limbs and lives more than is generally appreciated. Delay in diagnosis after blunt trauma led to major amputation in 21 percent of our patients. Current principles avoid those hazards. Five patients presented with acute limb ischemia caused by dissecting hematoma of the aorta. Suspicion of that diagnosis is warranted in patients without a history of chronic vascular occlusive disease or cardiac disease, in young white males with Marfan characteristics, and in middle-aged hypertensive black males. Confirmation of the diagnosis requires urgent angiography. In selected cases, treatment with femorofemoral bypass will be limb- and life-saving. Ischemia due to low flow, which portends a dire prognosis, should be suspected in severely ill patients with a history of peripheral vascular disease. Analysis of cardiac and metabolic functions with the Automated Physiologic Profile system identified the cause of the low flow state in 10 patients, permitting precise management with specific therapy. A discernible improvement in circulatory status of the limb coincided with correction of the low flow states. Angiography and surgery were not necessary in 90 percent of this group, and should be avoided during low flow episodes.
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PMID:Unappreciated causes of ischemia in the leg. 710 30

DT, a 63-year-old white male with insulin-dependent diabetes mellitus and severe peripheral vascular disease, was admitted with a five-day history of vague abdominal pain and diarrhea. On the day of admission he vomited three times, was noted to have a bloody stool, and came to the emergency room. DT denied hematemesis, fever, or chills. He had bilateral leg amputations and had sustained three myocardial infarctions, the last one 15 months before this admission. He had never experienced symptoms of abdominal angina. Of significance was his history of congestive heart failure, mitral regurgitation, and atrial fibrillation. His medications on admission included digoxin 0.25mg per day, furosemide 40mg per day, and NPH insulin 15 units per day. On admission to the hospital his oral temperature was 38 degrees C, pulse was 90/min, respiratory rate was 24/min, and blood pressure was 134/80mmHg. Abdominal examination revealed a distended abdomen with hypoactive bowel sounds and mild tenderness. Chest x ray revealed cardiomegaly. The electrocardiogram demonstrated atrial fibrillation. A plain film of the abdomen was positive for gallstones and edema of the bowel wall (thumb-printing). Laboratory results included blood urea nitrogen 48mg%, creatinine 1.2mg%, hemoglobin 18g/dl, and hematocrit 52.9%. White blood cell count was 11,900 cells/cc with 33% polymorphonuclear leukocytes, 47% bands, 8% lymphocytes, 11% monocytes, and 1% atypical lymphocytes. The prime considerations for differential diagnosis were mesenteric ischemia and infectious gastroenteritis. While it was appreciated that mesenteric ischemia, if present, might warrant surgical intervention, the risk of anesthesia itself in this patient was felt by his attending physicians to exceed 30%. Furthermore, the clinical findings were only "suggestive" of mesenteric eschemia. They were certainly not "diagnostic." In view of this dilemma, a consultation with the Division of Clinical Decision Making was requested.
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PMID:Abdominal pain, atherosclerosis, and atrial fibrillation. The case for mesenteric ischemia. 716 38

The radioactive isotope thallium 201 behaves physiologically as a potassium analog, and when injected intravenously accumulates rapidly within the cells of many organs. Uptake of the isotope reflects both regional perfusion and sodium-potassium pump activity. The radionuclide emits 80 keV x-rays which are suitable for scintillation camera imaging. The main clinical application of (201)TI scintigraphy has been in myocardial imaging. Abnormal uptake of the isotope results in a cold spot on the myocardial image. In patients with coronary artery disease, the differentiation of ischemic and infarcted myocardium is made by comparing images obtained after injecting the radionuclide at the peak of a maximal exercise test with those obtained after injection at rest. Abnormalities due to ischemia usually are seen only on the stress image whereas fixed defects in both rest and stress studies usually indicate areas of infarction or scarring. Some investigators believe that redistribution images obtained four to six hours after stress injection (without administering further (201)TI) give the same information as a separate rest study. The sensitivity of stress imaging for detecting significant coronary disease is of the order of 80 percent to 95 percent, though computer processing of the images may be necessary to achieve the higher figure. The prediction of the extent of coronary disease from (201)TI images is less reliable. An abnormal (201)TI image is not entirely specific for coronary artery disease and the likelihood of an abnormal image being due to this diagnosis varies according to the clinical circumstances. The main clinical value of (201)TI myocardial imaging is likely to be in the noninvasive screening of patients with atypical chest pain or with ambiguous findings on stress electrocardiographic tests. It has also proved useful in studying patients with variant angina or following a coronary bypass operation. It is doubtful whether the technique is clinically helpful in most patients with suspected or established acute myocardial infarction. Imaging of organs other than the heart with (201)TI has received much less attention but has been reported in patients with peripheral vascular disease and various primary and secondary neoplasms.
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PMID:Thallium 201 scintigraphy. 722 45

The innervation of lower limb epineurial arterioles, specimens of which were obtained from six patients in the sympathectomy and from six patients in the nonsympathectomy diabetic groups at amputation for ischemic peripheral vascular disease, was compared by quantitative ultrastructural methods. Results demonstrated no statistically significant difference in the number of vasomotor axons present, the average axon to smooth muscle cell distance or the axon distribution pattern in the adventitia between the two diabetic groups of patients. A previous investigation has established that innervation of these arterioles is significantly reduced in patients with diabetes having end-stage ischemia of the lower limb when compared with similar patients without diabetes. The present results demonstrate that surgical lumbar sympathectomy does not significantly further reduce the already severely diminished number of vasomotor nerves in some diabetic arterioles. This observation offers a possible explanation for the poorer success rate of those with diabetes compared with those without diabetes in avoiding amputation of the limb after lumbar sympathectomy.
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PMID:Effect of surgical lumbar sympathectomy on innervation of arterioles in the lower limb of patients with diabetes. 724 72

In evaluating the arterial hemodynamics of the lower extremities in patients with peripheral vascular disease, the treadmill exercise test offers useful information concerning the peripheral circulation. The addition of electrocardiographic (EKG) monitoring during the treadmill examination provides a method of estimating the effectiveness of coronary circulation. In three groups of patients studied, the results demonstrated that EKG monitoring during the treadmill exercise test will reveal previously unsuspected arrhythmias and ischemia. Thus the safety of the patient is enhanced. In patients followed through the operative period, there was a high correlation between exercise-induced EKG changes and perioperative cardiac problems. The value of EKG monitoring during treadmill testing is clear and offers predictive information to the surgeon contemplating a revascularization procedure.
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PMID:The value of electrocardiogram monitoring during treadmill testing for peripheral vascular disease. 745 2

Atheromatous plaque material containing cholesterol crystals may dislodge and cause distal ischemia. To characterize atheroembolic renal failure, we retrospectively evaluated all patients at the Massachusetts General Hospital from 1981 to 1990 with both renal failure and histologically proven atheroembolism after angiography or cardiovascular surgery. Over the 10-year period, 52 patients were identified. They tended to be elderly men with a history of hypertension (81%), coronary artery disease (73%), peripheral vascular disease (69%), and current smoking (50%). Within 30 days of their procedure, only 50% of patients had cutaneous signs of atheroembolism, and 14% had documented blood eosinophilia. Urinalysis was often abnormal. Hemodynamically unstable patients died shortly after their procedure, yet renal function in the remainder continued to decline over 3 to 8 weeks. Patients who received dialysis had a higher baseline serum creatinine than those who did not (168 +/- 44 mumol/L versus 133 +/- 18 mumol/L, p = 0.02), with dialysis starting a median of 29 days after the procedure. Patients with renal failure due to atheroembolism alone, as opposed to multiple renal insults, were more likely to recover renal function (24% versus 3%, p = 0.03) and had a lower risk of death during the 6 months after their procedure (log-rank p = 0.002). Renal failure due to procedure-induced AE is characterized by a decline in renal function over 3 to 8 weeks. This time course is not consistent with most other iatrogenic causes of renal failure, such as radiocontrast or nephrotoxic medications, which present earlier and often resolve within 2 to 3 weeks after appropriate intervention.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Atheroembolic renal failure after invasive procedures. Natural history based on 52 histologically proven cases. 750 Aug 98

Increased pressures on health-care budgets mean that governments require good value for money from the resources devoted to health care. In many countries, measures have been introduced to increase efficiency or to contain health-care costs. These include price controls, limitations on reimbursement of health technologies, budgetary reform in health-care institutions, and the encouragement of competition. Given this changing environment, it is important that drugs and other health technologies be shown to give good value for money. The methods of economic evaluation, such as cost-benefit and cost-effectiveness analysis, can be used to assess the value of drugs and other health technologies. They have been widely applied. The economic evaluation of drugs in peripheral vascular disease and stroke would compare the cost of adding the drug with its benefits. These would include improvements in length and quality of life and the savings in treating vascular events that may be postponed, or lessened in intensity, by effective drug therapy. One study, following a clinical trial of naftidrofuryl in stroke, suggested that there would be significant reductions in costs through reductions in hospital stay if recovery was aided. Further research and a large multicenter trial are under way to confirm these findings. In peripheral artery disease there are no economic data collected alongside clinical trials. It is known, however, that the costs of leg ischemia can be significant. A study in the U.K. found that arterial construction would cost around pounds 7,750 per person (1989 prices) and amputation around pounds 11,000 per person.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Economic evaluation of drugs in peripheral vascular disease and stroke. 751 76

Ischemia is thought to be a major component in the pathogenesis of foot problems. The authors use the Xe-133 washout method to evaluate the blood perfusion of muscle tissue in the lower legs of patients with noninsulin-dependent diabetes mellitus (NIDDM). Eighty-five male patients with NIDDM ranging in age from 51 years to 79 years (mean, 66.5 years) and 47 nondiabetic control males with a matched age ranging from 52 years to 82 years (mean, 64.5 years) were included in this study. None of the diabetics had a history or presentation of peripheral vascular disease in the lower limbs. The patients were separated into groups according to the duration of the disease and condition of blood sugar control. The Xe-133 washout method was performed in the anterior tibial muscle of all the subjects. According to a Student's t-test, the tissue perfusion were of significant difference between 1) NIDDM and normal controls (1.98 +/- 1.39 ml/100 g/minute versus 2.85 +/- 1.35 ml/100 g/minute), 2) good and poor blood sugar control (2.36 +/- 1.58 versus 1.51 +/- 0.94), and 3) long and short disease durations (1.50 +/- 0.78 versus 2.35 +/- 1.63). It is concluded that the tissue perfusion in the lower legs of patients with NIDDM is significantly decreased and related to the duration of the disease and condition of blood sugar control. This may contribute to the high incidence of foot gangrene and limb loss in patients with NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evaluation of tissue perfusion by the Xe-133 washout method in lower limbs of patients with noninsulin-dependent diabetes mellitus. 762 52


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