Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0920646 (renal ischemia)
 2,515 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In addition to their role as highly potent antihypertensive drugs, calcium antagonists may also play an important future role in the area of tissue protection and preservation. Calcium antagonists exert favorable effects on renal hemodynamics related to their reversal of renal vasoconstrictors. Calcium antagonists are also capable of blocking intracellular calcium overload induced by various types of ischemic or toxic stimuli. Features such as these may be of substantial value in ameliorating acute renal insufficiency secondary to renal ischemia, iodinated radiographic contrast agents, or the administration of various nephrotoxic drugs. The latter includes agents such as the aminoglycoside antibiotics, cyclosporine A, and the cancer chemotherapeutic agent cisplatin. Recent prospective, controlled studies from our group indicate that calcium antagonists protected against postischemic acute renal failure in the setting of cadaveric renal transplantation. Moreover, in a prospective, randomized, controlled clinical trial, we were able to demonstrate that the prophylactic use of nitrendipine reduced the decrease in GFR in patients receiving radiographic contrast agents. Calcium antagonists may also play a beneficial role in preventing progressive renal disease. Data from a number of studies conducted in experimental animals, as well as information from clinical trials, support such a view. Although the mechanisms of action of calcium antagonists in the setting of chronic renal failure are not yet fully established, their beneficial effects may be related to protective actions such as the reduction in renal hypertrophy, modulation of mesangial cell uptake of macromolecules, changes in permselectivity of the glomerulus, and a decreased free radical formation. These various aspects will be the topic in this review.
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PMID:Renal protection with the calcium antagonists. 172 49

The aneurysms of the abdominal aorta requiring suprarenal clamping are rare. Suprarenal clamping was required for only 43 of 544 aneurysms operated electively from 1981 to 1989. Twenty-five patients had a juxtarenal aneurysm, without any normal aortic segment under the renal arteries, and suprarenal clamping was therefore necessary while the upper anastomosis was being established (group I). Eighteen patients had an aneurysm enclosing the root of at least one renal artery (group II). Several prognostic factors have been assessed: patient's age, presence of preoperative renal insufficiency, of arterial hypertension or of coronary insufficiency, and revascularization method. Five patients died. Four of them belonged to group II and were over 75 years old. All presented with a preoperative renal insufficiency. Two of these deaths were caused by mesenteric infarction. Four cases of regressive postoperative renal insufficiency were observed in patients for whom renal clamping had lasted longer than 45 minutes. This study allowed outlining three prognostic factors: the patient's age, preoperative renal insufficiency, a period of renal ischemia exceeding 40 minutes. On the other hand, the severity of hypertension had no predictive value. Coronary insufficiency requires a strict hemodynamic surveillance, but is not a contraindication for revascularization.
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PMID:[Early prognostic factors of the surgery of aneurysms of the abdominal aorta with renal artery clamping]. 176 86

With the exception of conventional angiography, no previously proposed screening test has the necessary sensitivity/specificity to guide further evaluation for correctable renovascular disease. Recently, renal duplex sonography has been suggested as a useful substitute in such screening for renovascular disease. This report analyzes our data collected over the past 10 months in evaluation of renal duplex sonography to examine its diagnostic value. The study population for renal duplex sonography validity analysis consisted of 74 consecutive patients who had 77 comparative renal duplex sonography and standard angiographic studies of the arterial anatomy to 148 kidneys. Renal duplex sonography results from six kidneys (4%) were considered inadequate for interpretation. This study population contained 26 patients (35%) with severe renal insufficiency (mean 3.6 mg/dl) and 67 hypertension (91%). Fourteen patients (19%) had 20 kidneys with multiple renal arteries. Bilateral disease was present in 22 of the 44 patients with significant renovascular disease. Renal duplex sonography correctly identified the presence of renovascular disease in 41 of 44 patients with angiographically proven lesions, and renovascular disease was not identified in any patient free of disease. When single renal arteries were present (122 kidneys), renal duplex sonography provided 93% sensitivity, 98% specificity, 98% positive predictive value, 94% negative predictive value, and an overall accuracy of 96%. These results were adversely affected when kidneys with multiple (polar) renal arteries were examined. Although the end diastolic ratio was inversely correlated with serum creatinine (r = -0.3073, p = 0.009), low end diastolic ratio in 35 patients submitted to renovascular reconstruction did not preclude beneficial blood pressure or renal function response. We conclude from this analysis that renal duplex sonography can be a valuable screening test in the search for correctable renovascular disease causing global renal ischemia and secondary renal insufficiency (ischemic nephropathy). Renal duplex sonography does not, however, exclude polar vessel renovascular disease causing hypertension alone nor does it predict hypertension or renal function response after correction of renovascular disease.
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PMID:Renal duplex sonography: evaluation of clinical utility. 220 35

The purpose of our article is to describe a patient with severe hypertension and moderate renal insufficiency, unstable angina, and a 6 cm abdominal aortic aneurysm. A previous aortogram had demonstrated severe bilateral renal artery stenoses. Cardiac catheterization demonstrated severe coronary disease. After cardiac catheterization acute renal failure and pulmonary edema requiring dialysis developed in the patient. In addition, evidence of impending myocardial necrosis developed. Because of the critical nature of the myocardial and renal ischemia it was necessary to perform combined myocardial and renal revascularization rather than staged procedures. At the time of coronary artery bypass grafting, a vein graft was anastomosed to the right coronary artery vein graft and tunneled through the diaphragm into the abdomen to revascularize both renal arteries. After surgery renal function gradually improved, and no further dialysis was required. The abdominal aortic aneurysm was repaired at a subsequent operation. At 2-year follow-up all grafts remained patent. The serum creatinine is 1.2 mg/dl. Although most patients with combined coronary artery disease and renal artery disease can be treated with staged operations, our procedure may be of value in patients in whom staged procedure are not feasible and in whom the infrarenal aorta is severely diseased or aneurysmal.
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PMID:Combined coronary artery bypass grafting and bilateral renal revascularization for unstable angina and impeding renal failure. 199 71

The authors studied clinical and biological data occurring in 165 patients observed during 23 years and afflicted with polyarteritis nodosa. Hypertension was present in 52 patients (31.5%) and seven of them suffered from malignant hypertension (4%). Mean age of patients (6 male, 1 female), with malignant hypertension was 38 +/- years old. Mean follow up was 49 +/- 28 months including 26 +/- 21 months after discontinuation of treatment of polyarteritis nodosa. Malignant hypertension occurred during the first year of evolution of polyarteritis nodosa. Renal insufficiency was present in 5 of 7 patients. Proteinuria was greater than 1 gr/d in 4 cases. Renal arteriography was performed in 6 patients and showed in every case renal ischemia and microaneurysms in five. In 4 patients measurements of plasma renin activity and of aldosterone were obtained. A stimulation of those hormones was demonstrated. Some symptoms of polyarteritis nodosa were present with a high incidence in case of malignant hypertension: digestive signs (6/7), orchitis (3/6). HBs antigen was present in 6 cases and hepatitis in 5. Captopril was effective in every case, alone or associated with other treatments. Follow up of hypertension went from 8 months to 4 years. At present time 6 patients are alive and one is lost of follow up. A treatment is necessary in 6 of 7 patients. Creatininemia is greater than 300 micromol/l in 4 patients. A successful kidney transplantation was performed in one case. Our study shows a close relation between malignant hypertension observed in polyarteritis nodosa, vascular nephropathy, digestive and urologic signs. Hepatitis B virus could be responsible of those manifestations.
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PMID:[Malignant arterial hypertension in periarteritis nodosa. Incidence, clinicobiologic parameters and prognosis based on a series of 165 cases]. 287 20

RCIRF is a complex syndrome resulting in acute renal dysfunction following exposure to radiologic contrast media. It accounts for 10 per cent of all cases of acute renal failure. The pathogenesis appears multifactorial but most probably involves contrast-mediated renal ischemia and direct tubular toxicity. Significant risk factors include preexisting renal insufficiency, diabetes mellitus, advanced age, volume depletion, and presence of multiple myeloma. The diagnosis should be suspected with acute renal dysfunction temporally related to radiologic contrast administration. The prognosis for recovery is good in most cases. Key preventive measures include identification of high-risk patients, ensuring adequate hydration prior to contrast agent administration, avoiding excessive and repeated contrast exposure, and instituting prophylactic therapy in selected cases.
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PMID:Radiologic contrast-induced renal failure. 329 29

These findings demonstrate that calcium antagonists reverse renal vasoconstriction in a variety of settings. The ability of calcium antagonists to augment GFR of the vasoconstricted kidney is striking and has also been demonstrated in a number of in vivo settings. These observations and others raise the possibility that calcium antagonists have potential utility in the treatment of a number of disorders characterized by renal ischemia and consequent renal insufficiency. Further studies to evaluate this possibility are required. The unique effects of calcium antagonists on GFR reflect a regional heterogeneity within the renal microcirculation and a preferential action of calcium antagonists on the afferent arteriole. Final resolution of the pharmacological basis for the renal hemodynamic actions of calcium antagonists will require a more complete understanding of the divergent activating mechanisms within the renal microcirculation.
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PMID:Calcium antagonists and the renal hemodynamic response to vasoconstrictors. 337 80

The operative treatment of 77 patients with atherosclerotic aneurysms of the pararenal aorta (54 juxtarenal and 23 suprarenal) is analyzed. Repair of these complex lesions is formidable because of difficult exposure, renal ischemia and myocardial strain as a result of proximal aortic occlusion, and associated renal atherosclerosis with secondary renal functional impairment. Nineteen (25%) patients were normotensive with normal renal function. Sixteen patients (21%) had hypertension alone and 42 (54%) were hypertensive with abnormal renal function. There were multiple renal arteries in 22% of patients. Aortic reconstruction involved infrarenal graft in 27 patients (35%), infrarenal graft plus pararenal aortic endarterectomy (TEA) in 26 (34%), and infra- and pararenal aortic graft in 24 (31%). Twenty-two patients (30%) had normal renal arteries and therefore no renal reconstruction. Of the 55 patients who required combined aortic and renal artery repair, 24 required renal artery repair because of involvement of the renal arteries by the aneurysm and 31 because of atherosclerotic renal artery disease. TEA was the most common technique of renal artery repair (54 of 93 arteries, 58%), followed by reimplantation (18 arteries) and prosthetic graft (13). The perioperative mortality rate was 1.3%. The perioperative morbidity rate was 28% and consisted principally of renal insufficiency (23%). This was usually transient (44%) and (89%) mild. Renal morbidity was adversely affected by renal ischemia status, severity of renal artery disease and extent of renal revascularization. Following reconstruction, hypertension was cured or improved in 77% of patients and abnormal renal function was cured or improved in 46% and stabilized in an additional 39% of patients. These results show that combined aortic aneurysm repair and renal artery reconstruction can be performed with minimal mortality and an acceptable morbidity. Aggressive intraoperative monitoring is necessary to minimize myocardial complications. Careful attention must be paid to the technical details of the reconstruction, especially in minimizing renal ischemia, to reduce the subsequent incidence of renal function deterioration.
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PMID:Management of pararenal aneurysms of the abdominal aorta. 394 85

Acute renal failure (ARF) is defined as a renal insufficiency of sudden onset (increase of creatinine and urea in the serum) combined with or without oliguria (less than 500 ml of urine per day). Nephrotoxins (drugs, contrast medium) or renal ischemia (hypovolemia, hypotension, shock, septicemia, treatment with CEI) may affect the renal tubulus through several pathways, all of which may result in ARF. Ultrasound allows to distinguish hydronephrosis from ARF which is characterized by increased width of the parenchyma and low echodensity of the medulla. ARF is usually reversible. If conservative therapy fails, dialysis treatment is necessary.
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PMID:[What should the general practitioner know about diagnosis and treatment of acute kidney failure?]. 778 97

Although the new nonionic contrast agents are safer than ionic agents, renal insufficiency and even death still occur occasionally. Therefore, we have explored the use of carbon dioxide (CO2) as an alternative angiographic contrast agent used in combination with digital subtraction angiography. Clinical observations have been made in over 800 patients. The images obtained are of equivalent diagnostic quality compared with those using conventional iodinated contrast agents. Recent advances in imaging, including "stacking," provide images comparable with iodinated contrast. Very small vessels, equivalent to third-order branches of the renal artery, can be imaged satisfactorily with CO2. Occasional studies with CO2 yield information not apparent with iodinated contrast agents, including excellent visualization of arteriovenous shunts, collateral circulations, malignant tumors, and minute amounts of arterial bleeding. Many of the advantages and disadvantages of CO2 derive from its special physical and chemical properties. The advantages include no allergic potentiation and no renal metabolism of CO2, because CO2 is cleared by the lungs and does not recirculate. Other advantages include delivery by very small catheters because of the low viscosity of CO2, minimal discomfort on injection, and very low cost. However, the low-density and compressibility of CO2 poses some special problems. Imaging requires digital subtraction angiography with electronic enhancement and injections require an experienced investigator and, ideally, a dedicated CO2 injector. The dedicated CO2 injector provides calculated, controlled dosing and rates for injection, while excluding the possibility of air contamination. The buoyancy of CO2 inhibits good filling of dependent vessels. Accordingly, CO2 does not normally produce good nephrographic images, although proximal renal arteries are normally shown clearly. Experimental studies in dogs, whose renal arteries have been injected repeatedly with very large doses of CO2, demonstrate only transient changes in renal blood flow and no endothelial cell damage. However, these studies also showed clearly that renal ischemia can occur due to a "vapor lock" phenomenon if the kidney is positioned vertically above the injection site, and recurrent injections are given without time for absorption of the arterially delivered CO2 boluses. Uncontrolled studies in over 800 patients have confirmed that CO2 likely has a very low renal toxicity. At the University of Florida, CO2 is the radiologic contrast agent of choice in patients with renal insufficiency, especially those with diabetes mellitus, and in those with pre-existing allergy to iodinated contrast agents. Further controlled clinical studies are required to define the true clinical utility and safety of CO2 compared with conventional radiologic contrast agents.
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PMID:CO2 digital angiography: a safer contrast agent for renal vascular imaging? 794 29


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