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)

Fibromuscular dysplasia of renal arteries was the cause of hypertension in four consecutive children with renal artery stenosis. Two were asymptomatic, the third had had hypertension for seven years but had not been treated, and the fourth, a 9-month-old infant, presented with cardiac failure. Heart enlargement and left ventricular hypertrophy were present in all. Rapid sequence urograms demonstrated a smaller kidney and delayed appearance and disappearance of the contrast medium on the affected side in all. Angiograms showed left RAS in all. Peripheral plasma renin activity was elevated in only three of the four patients. Antihypertensive and diuretic drugs were not very effective therapeutically. Ischemia of the ipsilateral kidney probably prevented normal growth and led to shrinkage of the kidney in one patient. Following nephrectomy the BP has remained normal without any therapy for 24 to 64 months. With normalization of BP, accelerated growth ensued, the cardiomegaly regressed and the hypertensive retinopathy resolved. These patients demonstrate that: (1) FMD is an important cause of RAS. (2) the well-known radiologic feature of FMD, the beaded appearance, is usually not seen in children. (3) control of BP leads to normalization of linear growth, usually impaired in severe hypertension, and (4) target organ complications such as cardiomegaly, LVH, and hypertensive retinopathy are reversible in one to 10 months.
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PMID:Fibromuscular dysplasia of renal arteries: an important cause of renovascular hypertension in children. 15 54

We reviewed retrospectively 75 renal transplant arteriograms done during a 7-year period. Acute rejection and vasomotor nephropathy were not differentiated. Generalized cortical ischemia was diagnosed correctly in 23 of 30 cases but there were 7 falsely negative results. Renal artery stenosis was found in 7 of 17 cases in which the main indication for arteriography was hypertension. We conclude that the major role of transplant arteriography is in the diagnosis of larger vessel disease.
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PMID:Angiography in the diagnosis of renal allograft dysfunction. 34 73

To evaluate the effect of prostaglandin inhibition on the renal blood flow of the ischemic kidney, we administered indomethacin to 10 anesthetized dogs with renal artery stenosis and contralateral nephrectomy. Following the operation to produce renal ischemia, there was an increase of blood pressure associated with an increase of renin and the prostaglandins F1 (PGF1), and E (PGE). The administration of indomethacin to the intact, normotensive animals caused the anticipated decrease of prostaglandin E, renin, and renal blood flow. However, in the hypertensive dogs, indomethacin caused a paradoxical 45 per cent increase in the renal blood flow, despite a 44 per cent decrease of prostaglandin E. PGF1, PGE, renin, and erythropoietin exhibited the anticipated decreased levels. The study suggests that prostaglandins may not be the sole important factor in the regulation of renal blood flow in the presence of ischemia. Other important factors likely include the renin-sensitive angiotensin, the adrenergic, and the kallikrein-kinin systems.
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PMID:Paradoxical increase of renal blood flow in anesthetized hypertensive dog treated with indomethacin. 48

Three patients with severe hypertension secondary to renal artery stenosis were treated by renal autotransplantation. Of these 3 patients 2 had solitary kidneys and 1 had 2 renal arteries to each kidney, all of which were stenosed. Renal autotransplantation with hypothermia of the kidney was performed in all 3 patients rather than the more conventional arterial bypass or endarterectomy because 1) hypothermic preservation permitted a prolonged ischemia time and 2) there was improved exposure for the vascular anastomosis. Postoperatively 2 patients remained normotensive without drugs for 9 and 12 months and 1 patient died of septicemia not directly related to the autotransplant. All 3 patients required expansion of the intravascular volume postoperatively to overcome the loss of vasoconstrictor substances following restoration of renal blood flow.
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PMID:Renal autotransplantation using hypothermic storage and pulsatile perfusion. 109 39

The tests in the noninvasive vascular laboratory are highly accurate for assessing the patient with extremity or visceral artery disease. Once the location and severity of any arterial disease in patients with claudication or critical limb ischemia (ie, gangrene, ulceration, rest pain) is determined by the noninvasive tests, a treatment plan can be developed and then discussed with the patient, with consent obtained prior to any invasive procedure. The presence of hypertension from renal artery stenosis, or chronic mesenteric ischemia from visceral artery stenosis, can be evaluated by duplex scanning, without the need for invasive contrast angiography. Monitoring the function of revascularization procedures, such as angioplasty or bypass grafts, is also possible and significantly improves long-term patency and organ or limb salvage by identifying the need for elective revision of failing reconstructions prior to thrombosis. Noninvasive vascular laboratory tests are the initial procedures of choice for the evaluation of patients with extremity or visceral arterial disease.
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PMID:Indications and uses of the noninvasive vascular laboratory: extremity or visceral arterial evaluation. 206 53

Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3.
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PMID:99mTc renal tubular function agents: current status. 213 59

An 11-year-old boy with slowly progressive gangrene caused by vasculopathy similar to that of neurofibromatosis (NF) type 1 (NF I; von Recklinghausen disease [NFvR]) and a newborn girl with idiopathic gangrene with vascular changes resembling those of NFvR prompted the analysis of all 105 propositi with NF (NF I and NF II) evaluated between January 2, 1982, and December 31, 1986, at the genetics clinic of University of South Florida. They were analyzed for renal hypertension, symptomatic ischemia, and known vascular changes. One additional 27-month-old boy with NFvR was found to have extensive vascular changes with renal hypertension. The vasculopathy indicated asymmetric over/undergrowth of cellular and extracellular components of the vascular wall and implied dysregulation of the paracrine growth mechanism. Immunocytochemical studies of affected vessels were done only in the 11-year-old boy and showed positive neuron-specific enolase, S-100 protein, and glial fibrillary acidic protein (GFAP) reactions indicative of Schwann cell involvement. The vascular changes in children with NFvR are mostly asymptomatic; however hypertension secondary to renal artery stenosis and/or Moya-moya disease have been reported infrequently. Our patients with vasculopathies provoked thoughts in regard to the so-called vascular NF, its place in current NF nomenclature and classification, relationship to fibromuscular dysplasia (FMD), and possible role in infantile gangrene.
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PMID:"Vascular neurofibromatosis" and infantile gangrene. 251 May 17

PTA is an established method of revascularization in a variety of medical conditions. It is performed for specific morphologic and clinical indications. PTA is the procedure of choice in Fontaine stage IIB through IV lower extremity ischemia due to iliac and/or femoropopliteal stenosis or short occlusion. Its role is less certain in infrapopliteal disease, although current studies have begun to establish long-term effectiveness. PTA is the procedure of choice for renal revascularization in renovascular hypertension due to fibromuscular disease or non-ostial atherosclerosis, selected cases of renal artery stenosis associated with renal insufficiency, and transplant renal artery stenosis. It is also useful in treating the renovascular component of complex hypertension and may be indicated in severe renal artery stenosis (75%-99%), even in the absence of clinically demonstrable RVHTN. PTA has limited applications in the venous system and only short-term success in the treatment of stenoses in dialysis access fistulas. PTA often serves as an important adjunct to surgical revascularization by providing improved inflow or outflow. PTA is the procedure of choice when anatomically feasible in subclavian steal syndrome. The role of PTA in carotid artery disease, particularly atheromatous disease of the internal carotid artery, is uncertain. The same may be said of PTA for vertebral artery stenosis, although the overwhelming majority of vertebral artery stenoses are morphologically suitable for PTA. PTA and surgery are both effective in the treatment of abdominal angina. There are more data available to verify the long-term patency of thromboendarterectomy and bypass grafts than PTA for mesenteric ischemia. However, since the technical success for PTA is high and since coronary co-morbidity is the most common cause of perioperative mortality in surgical series, PTA should be seriously considered as the procedure of first choice. Serious complications of PTA occur in approximately 5% of cases. Two to three percent of PTA patients have complications requiring surgery or causing a prolongation or alteration of hospital course. The morbidity, mortality, and cost associated with PTA are low. The discomfort is minor, and postprocedural recovery rapid. The major limitations of PTA include its unsuitability for some lesions (long-segment occlusions and stenoses, orifice lesions, eccentric lesions) and postangioplasty restenosis. These problems are being addressed by ongoing laboratory and clinical research. In the near future, it is likely that endoluminal transmural sonography of the vessel wall will help guide our interventions.
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PMID:Noncoronary angioplasty. 252 45

A patient with a right renal artery stenosis and renovascular hypertension was admitted for balloon dilation of the stenotic artery. During the procedure the catheter entered the superior mesenteric artery and caused a mural dissection and occlusion, which was successfully treated by endarterectomy and vein patch angioplasty. Delayed ischemia of the transverse colon required resection and colostomy, but the patient recovered fully after colostomy closure and cholecystectomy were performed.
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PMID:Intramural dissection of superior mesenteric artery. A complication of attempted renal artery balloon dilation. 315 53

To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.4 T research MRI unit. T1 was calculated using four inversion recovery sequences with different inversion times. Renal blood flow, using 113Sn-microspheres, and regional water content by drying were then measured. The average T1 of the inner medulla was shorter for the ischemia (1574 msec) than for the contralateral kidney (1849 msec), while no change ws noted in the cortex. Ischemic kidneys had less distinct outer medullary zones on IR images with TI = 600 msec than did contralateral or control kidneys. Blood flow to both the cortex and medulla were markedly reduced in ischemic kidneys compared with contralateral kidneys (119.5 vs. 391 ml/min/100 gm for cortex and 19.8 vs. 50.8 ml/min/100 gm for medulla). Renal water and blood content were less affected. Our rabbit model of renal artery stenosis with MRI, radionuclide, and angiographic correlation has the potential to increase our understanding of MR imaging of the rabbit kidney.
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PMID:Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow. 337 82


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