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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differential diagnosis between essential hypertension and secondary arterial hypertension (AH) that developed in the presence of chronic pyelonephritis was made in 12 patients with AH and the urinary syndrome (leukocyturia and bacteriuria). With that purpose in view for revealing functional renal asymmetry, a study was made of the effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) in each kidney separately based on computation of 99Tc-DTPA and 131I-hippuran clearances. Some patients in whom AH was later regarded as essential manifested practically equal values of the ERPF and GFR from both sides, with the real characteristics of the latter ones being little different from the respective populational values calculated by computer bearing in mind the body surface of those patients. The other patients' group showed, along with a decrease of the total ERPF and GFR, a dramatic asymmetry of the intrarenal hemodynamics of both ERPF and GFR, which is fairly characteristic of chronic pyelonephritis. This allows the syndrome of AH to be regarded in those patients as secondary.
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PMID:[The determination of the separate intrarenal hemodynamics and its place in the diagnosis of nephrogenic arterial hypertension]. 221 11

We performed indium-111-DTPA plasma clearance studies in 61 pediatric kidney and liver recipients treated with cyclosporine to compare true glomerular filtration rate with calculated GFR (cGFR). The mean true GFR of 61.9 +/- 36.6 ml/min/1.73 m2 indicated renal impairment. The mean cGFR of 85.2 +/- 22.4 ml/min/1.73 m2 was significantly higher (P less than 0.001), and overestimated GFR by 38%. cGFR alone did not accurately reflect the degree of renal dysfunction. A group of 48 pediatric orthotopic liver transplant recipients was studied in more detail: 73% of these patients had a true GFR less than 70 ml/min/1.73 m2, while 85% had a true GFR below 90 ml/min/1.73 m2, the lower limit for normal GFR in children. The mean true GFR for patients treated more than 24 months with CsA was lower (P = 0.02) than patients treated with CsA for 12 to 24 months. OLT patients with normal true GFR (greater than 90 ml/min/1.73 m2) had significantly lower plasma CsA levels, and 50% of patients with a true GFR less than or equal to 50 ml/min/1.73 m2 had hypertension. There was no effect on true GFR of age, liver function, azathioprine use, or peritransplant treatment with other nephrotoxic drugs. We conclude that true GFR is significantly impaired in long-term CsA-treated allograft pediatric recipients. Calculations of GFR underestimate the degree of renal dysfunction. As patients treated greater than 24 months had the lowest true GFRs, the fall in GFR may be progressive.
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PMID:The impairment of true glomerular filtration rate in long-term cyclosporine-treated pediatric allograft recipients. 230 Oct 34

Using a recently described new technique, individual kidney filtration fraction was measured from the first 3 min of the Tc-99m DTPA renogram in a series of 11 subjects without evidence of renal disease and in 23 patients with hypertension. Fourteen of these hypertensives had angiographic evidence of renal artery stenosis (RAS) but only 2 had proven renovascular hypertension (RVH). In addition, renal blood flow (RBF), expressed as a fraction of cardiac output, was measured from the first pass time activity curves following bolus injection of Tc-99m DTPA, and individual kidney glomerular filtration rate (IKGFR) was measured from the subsequent plasma Tc-99m DTPA clearance and renographic divided function. An estimation of filtration fraction based on these measurements of RBF and IKGFR correlated rather poorly with that directly based on the renogram, although both showed directionally similar changes in the hypertensive patients following inhibition of angiotensin-converting enzyme (ACE) with captopril. Filtration fraction by both estimates fell significantly after ACE inhibition in patients with RAS and essential hypertension, while RBF increased. IKGFR showed no change in essential hypertension or in hypertensive patients with RAS but fell sharply in 3 renal units in 2 patients with RVH. This renographic method for measuring filtration fraction is worthy of further elaboration and might be a simple and useful discriminator of RVH in a hypertensive population.
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PMID:Filtration fraction.noninvasive measurement with Tc-99m DTPA and changes induced by angiotensin-converting enzyme inhibition in hypertension. 250 Jun 11

We compared the ability of three aerosolized tracers to discriminate among control, lung inflation with a positive end expired pressure of 10 cmH2O, lung vascular hypertension and edema without lung injury, and lung edema with lung injury due to intravenous oleic acid. The tracers were 99mTc-diethylenetriaminepentaacetate (99mTc-DTPA, mol wt 492), 99mTc-human serum albumin (99mTc-ALB, mol wt 69,000), and 99mTc-aggregated albumin (99mTc-AGG ALB, mol wt 383,000). 99mTc-DTPA clearance measurements were not able to discriminate lung injury from lung inflation. The 99mTc-AGG ALB clearance rate was unchanged by lung inflation and increased slightly with lung injury. The 99mTc-ALB clearance rate (0.06 +/- 0.02%/min) was unchanged by lung inflation (0.09 +/- 0.02%/min, P greater than 0.05) or 4 h of hypertension without injury (0.09 +/- 0.04%/min, P greater than 0.05). Deposition of 99mTc-ALB within 15 min of the administration of the oleic acid increased the clearance rate to 0.19 +/- 0.06%/min, which correlated well with the postmortem lung water volume (r = 0.92, P less than 0.01). This did not occur when there was a 60-min delay in the deposition of 99mTc-ALB. We conclude that 99mTc-ALB is the best indicator for studying the effects of lung epithelial injury on protein and fluid transport into and out of the air spaces of the lungs in a minimally invasive manner.
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PMID:Comparison of three tracers for detecting lung epithelial injury in anesthetized sheep. 250 Dec 80

Two different methods to assess the change of split renal function following angioplasty or bypass grafting were studied in a total of 12 patients with renovascular hypertension. The studies were performed before and within seven days after the therapeutic intervention. Split effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) after injections of I-131 hippuran and Tc-99m DTPA were measured using kidney counting corrected for depth and dose, described by Schlegel and Gates. In six of 10 patients with unilateral renal artery stenosis and in two patients with bilateral renal artery stenoses (two of 4 affected kidneys), the split renal function was improved after the therapeutic intervention, in accordance with the drop in blood pressure and the reduction of plasma renin activity. The improvement in ERPF and GFR was more likely in the patients without severely reduced renal function. In such patients, the improvement in ERPF was more pronounced than that in GFR. And in two patients with functional improvement, the Captopril-induced reduction of split GFR in the affected kidney was disappeared after the intervention. Moreover, in the long-term follow-up of three patients with functional improvement, one patient showed the deterioration of split renal function suggesting the relapse of renal artery stenosis. These results suggest that the combined studies of split ERPF and GFR determinations can be useful to evaluate the therapeutic effect as well as the presence or absence of functional improvement after the intervention.
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PMID:[Assessment of split renal function before and after angioplasty or bypass grafting in the patients with renovascular hypertension]. 253 Mar 76

We studied 11 hypertensive patients by a radionuclide technique using Gates' method with [99mTc]DTPA to investigate the acute effects of captopril on glomerular filtration rate (GFR). Five patients had hypertension with unilateral renal artery stenosis (RAS) angiographically documented and six patients had essential hypertension (EH). Total and split GFR were determined under control conditions and after oral administration of captopril (50 mg). In the patients with RAS, captopril induced a significant decrease of GFR in the stenotic kidneys (from 42.4 +/- 4 to 29.6 +/- 3 ml/min, p less than 0.01), while no changes were observed in the nonstenotic kidneys (from 61.2 +/- 3 to 61.6 +/- 5 ml/min, NS). Total GFR was 103.6 +/- 5 ml/min under control conditions and decreased to 91.8 +/- 6 ml/min after captopril (p less than 0.05). No significant changes of GFR were detected after captopril administration in patients with EH. In a separate group of ten patients with EH, good correlation between 24-hr creatinine clearance and fractional uptake of [99mTc]DTPA was obtained. Good reproducibility of this radionuclide technique was also shown. This study demonstrates that the computed radionuclide GFR determination coupled with the captopril test allows one to unmask angiotensin II-dependent renal function and hemodynamic changes. This technique can be useful in clinical practice for identifying patients with renovascular hypertension.
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PMID:Renal artery stenosis detection by combined Gates' technique and captopril test in hypertensive patients. 266 99

The effective renal plasma flow (ERPF), the rate of glomerular filtration and filtration fraction were investigated in 48 patients with nephrogenic hypertension (NH) using the method of dynamic renoscintigraphy with a double label (131I-hippuran and 99mTc-DTPA). The proposed method of noninvasive combined assessment of renal function was shown to be simple to perform and permitted the determination of a degree of involvement of the glomerular and tubular apparatus of the kidneys in NH. The comparison of renoscintigraphic and histomorphological results made it possible to determine renoscintigraphic criteria of glomerulo- and nephrosclerosis.
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PMID:[A radionuclide study of the renal filtration fraction in nephrogenic hypertension]. 265 41

Identification of patients with renovascular hypertension (RVH) among the larger group of patients with essential hypertension has been aided by a wide variety of in vitro and in vivo nuclear medicine procedures. The most valuable in vitro procedure remains the radioimmunoassay (RIA) for renin activity obtained from individual renal vein catheterization studies. Lateralizing renin activity provides valuable prognostic information about the likelihood for surgical cure of RVH. Older in vivo procedures for the diagnosis of RVH included rectilinear scanning and probe renography, which suffered from poor resolution and specificity, respectively. These tests have been replaced by computer-interfaced gamma camera scintirenography using 131I- or 123I-labeled orthoiodohippurate (OIH), or scintiangiography using 99mTc-DTPA. False-positive (FP) results for RVH persist due to a wide variety of relatively common conditions that can cause asymmetric renal size and function, including outflow obstruction and parenchymal renal disease. Newer approaches promise to improve the specificity of nuclear medicine procedures for identification of RVH. In particular, the number of FP exams appears to improve when scintirenography is performed before and after the administration of oral angiotensin converting enzyme (ACE) inhibitors, using either 99mTc-DTPA or OIH. The incentive for improved diagnostic testing has increased with the availability of percutaneous transluminal angioplasty (PCTA) for treatment of renal artery stenosis (RAS). Follow up of PCTA with scintirenography is of great value in assessing its effect on renal function and in evaluating the subsequent clinical course of the patient.
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PMID:Differential diagnosis and management of renovascular hypertension through nuclear medicine techniques. 265 10

To check the reliability of the captopril test and of quantitative radioisotope techniques for the primary diagnosis of renovascular hypertension the data from 41 patients suspected of this disease were retrospectively analysed. In all cases plasma renin activity (PRA) was assayed in peripheral blood and in renal vein blood before and after 25 mg captopril. Double tracer studies with 131I-hippuran and 99mTc-DTPA were also performed, as was renal arteriography. The postoperative blood pressure plots of 23 patients with unilateral renal artery stenosis (who had subsequently been operated upon) were included in the evaluation. Renovascular hypertension was diagnosed in 21 patients and essential hypertension in 20. Twelve of the 20 patients with essential hypertension had renal artery stenosis, but this had not produced renovascular hypertension. The diagnostic significance of the tests as markers of renovascular hypertension was as follows: captopril test P less than 0.001, glomerular filtration fraction P less than 0.02, hippuran clearance P less than 0.001. The captopril test and the quantitative radioisotope techniques were in agreement in identifying patients with renal artery stenosis and renovascular hypertension. False-positive results due to methodological shortcomings can be avoided by applying both methods in succession.
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PMID:[Endocrine and nuclear medicine diagnosis of renovascular hypertension]. 268 83

Sixty-four selected hypertensive patients, aged 17-45 years, were evaluated for renovascular hypertension. They were studied with 99mTC-DTPA Dynamic Renal Scanning (DRS) and Intravenous Digital Subtraction Angiography (IV-DSA). Intra-arterial DSA was further performed to demonstrate renal vascular anatomy in all disputable cases. Agreement of diagnosis occurred in 58 patients (32 with renal artery stenosis). There was one false positive with DRS and one false positive with IV-DSA. In another four patients with proven renovascular disease, IV-DSA was positive while DRS negative, but in two of them the stenotic lesion was considered insignificant, as they failed to respond to percutaneous transluminal dilatation (PTA). In contrast, nearly all patients whose hypertension improved after PTA or surgery had positive DRS and greater than 40% reduction of relative function of the affected kidney. IV-DSA yielded better results than DRS in the detection of renal arterial stenosis (especially whenever bilateral stenosis or rich collateral circulation was present), but DRS showed better correlation with the functional significance of a certain vascular abnormality. Thus the combination of the two methods seems to be a reasonable diagnostic approach to hypertensive patients with the aim of selecting those with curable hypertension due to renal vascular disease.
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PMID:Investigation of renovascular hypertension with 99mTC-DTPA dynamic renal scanning and digital subtraction angiography. 268 92


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