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Biomedical subjects

J V Nally

Publications and source records attributed to J V Nally.

33 records · Page 2Linked to original sources
PubMed1989

The captopril tests: a new concept in detecting renovascular hypertension?

An undetermined percentage of the 60 million hypertensive Americans have potentially correctable renovascular hypertension (RVHT). Conventional plasma renin activity (PRA) determinations and radionuclide renography have limited sensitivity and specificity as screening tests for RVHT. Angiotensin-converting enzyme inhibition with captopril stimulates renin secretion and causes transient decreases in glomerular filtration rate and effective renal plasma flow within the stenotic kidney. Review of recent studies in hypertensive patients suggests that captopril stimulation of both PRA determinations and conventional renography may enhance the sensitivity and specificity of these studies in detecting RVHT.

Captopril↗
PubMed1987

Captopril renography in two kidney and one kidney Goldblatt hypertension in dogs.

In order to improve on the technique of noninvasive detection of renal artery stenosis, we studied the effects of angiotensin converting enzyme inhibition with captopril on individual kidney hemodynamics and function as assessed by technetium-99m diethylenetriaminepentaacetic acid [( 99mTc]DTPA) renal flow studies and iodine-131 orthoiodohippurate [( 131I]hippuran) renography in experimental Goldblatt's hypertension. In two-kidney, one-clip (renin-dependent) hypertension, captopril (1.5 mg/kg bolus with 1.5 mg/min infusion) reduced mean arterial pressure (MAP) and ipsilateral glomerular filtration rate (GFR) without changes in the contralateral kidney. Captopril infusion resulted in alterations in both the [99mTc]DTPA and [131I]hippuran studies, which were most evident in the 15-min [99mTc]DTPA renal flow studies. In one-kidney, one-clip (volume-dependent) hypertension, captopril reduced MAP but did not alter GFR, renal plasma flow, or the radionuclide studies. These studies suggest that the [99mTc]DTPA renal flow study coupled with captopril challenge may unmask intrarenal angiotensin II-dependent functional and hemodynamic changes of the stenotic kidney, and offers promise in the detection of renin-dependent hypertension.

Animals↗
PubMed1986

Effect of captopril on 99mTc-diethylenetriaminepentaacetic acid renograms in two-kidney, one clip hypertension.

In an effort to improve on the noninvasive detection of renal artery stenosis, we investigated the effect of angiotensin converting enzyme inhibition on computer-assisted 99mTc-diethylenetriaminepentaacetic acid (DTPA) renal flow studies in a canine model of two-kidney, one clip hypertension and compared these findings with clearances of inulin and p-aminohippuric acid in the stenotic and contralateral kidney before and after converting enzyme inhibition. The 99mTc-DTPA renal flow study with the converting enzyme inhibitor captopril (1.5 mg/kg bolus with 1.5 mg/min infusion) showed an increased sensitivity in the detection of unilateral renal artery stenosis over the use of the 99mTc-DTPA study alone. Captopril induced striking alterations that were most evident in the 15-minute 99mTc-DTPA renal flow study, in which all nine curves exhibited severely blunted uptake and excretion of the radionuclide. These changes were reversed during a recovery study without converting enzyme inhibition and were not seen when blood pressure was lowered with nitroprusside to a level similar to that observed during converting enzyme inhibition. The changes shown by the 99mTc-DTPA study during converting enzyme inhibition correlated with a decrease in the glomerular filtration rate of the stenotic kidney. Captopril infusion significantly decreased the glomerular filtration rate of the stenotic kidney (16.0 +/- 3.1 vs 11.0 +/- 2.5 mg/min, p less than 0.03) but not of the contralateral kidney (32.4 +/- 2.6 vs 28.4 +/- 2.8 mg/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Technetium-99m DTPA renal flow studies in Goldblatt hypertension.

Computer-assisted dynamic renal studies were performed on a group of 14 mongrel dogs before and after the induction of unilateral renal artery stenosis. Ninety-second technetium-99m diethylenetriaminepentaacetic acid ( [99mTc]DTPA), 15-min [99mTc]DTPA, and 30-min iodine-131 orthoiodohippurate ( [131I]hippuran) time-activity curves were analyzed and correlated with reduction of renal blood flow as measured by electromagnetic flow probe and PAH clearance techniques. Parameters of the 90-sec [99mTc]DTPA curves found to be significantly different for the same kidney before and after stenosis were: upslope, curve width at 75% maximum, maximum activity value, and differential (stenotic/contralateral) maximum activity ratio. For blood flow reductions greater than 33%, the [99mTc]DTPA studies were judged diagnostic of unilateral renal artery stenosis in all cases, whereas the [131I]hippuran time-activity curves were indicative of stenosis in only six of ten studies. Thus, in this model we find the computer-assisted 90-sec [99mTc]DTPA renal flow study to be superior to conventional [131I]hippuran renography in the diagnosis of moderate-to-severe unilateral renal artery stenosis.

Animals↗
PubMed1985

Improved computer-assisted nuclear imaging in renovascular hypertension.

Computer-assisted dynamic renal studies using both the 90 second 99mTc-DTPA and the conventional 30 minute 131I-Hippuran methods were performed in nine patients with angiographically proven renal artery stenosis. Time activity curves for both studies were derived from regions of interest selected from the computer-acquired dynamic images. The following parameters were used to assess renal blood flow: differential maximum activity, minimum/maximum activity ratio, and peak width. The computer-assisted DTPA study accurately predicted (9/9) the stenotic side documented angiographically, whereas the conventional Hippuran scan was clearly predictive in only 57% (5/9). The best discriminatory factors for the 90 second 99mTc-DTPA scan, when compared to a normal template synthesized from curves obtained from normal subjects (20), were differential maximum activity and peak width. In conclusion, the computer-assisted 90 second 99mTc-DTPA renal blood flow scan was superior to the conventional 30 minute 131I-Hippuran scan in demonstrating unilateral renovascular disease. The DTPA study was highly predictive of the angiographic findings, and this noninvasive study may prove useful in the diagnosis and serial evaluation following surgery or angioplasty in patients having renal artery stenosis.

Adult↗
PubMed1979

Acute thrombotic thrombocytopenic purpura. Another cause for hemolytic anemia and thrombocytopenia in cirrhosis.

Severe hemolytic anemia and thrombocytopenia developed in a 56-year-old man with Laennec's cirrhosis. Rather than having one or more of the expected causes for these problems associated with cirrhosis, he proved to have acute thrombotic thrombocytopenic purpura. Treatment with platelet antiaggregant drugs and exchange plasmapheresis was ineffective in controlling the disease. The presence of advanced liver disease may precipitate or complicate this unusual syndrome.

Acute Disease↗
PubMedDate not supplied

Tunneled right atrial catheter infection presenting as renal failure.

We report two cases of progressive renal failure secondary to membranoproliferative glomerulonephritis associated with subclinical septicemia from a tunneled right atrial catheter used for home parenteral nutrition administration. Although the occurrence of line infection and septicemia is a common complication of central venous catheters, a review of the literature reveals only one case report of renal failure secondary to an infected implanted central venous device. Both patients presented with azotemia and had biopsy-proven membranoproliferative glomerulonephritis, accompanied by leukocytoclastic vasculitis. In both cases, removal of the right atrial catheter and prolonged antibiotic therapy was effective in resolving the ongoing infection and resulted in marked improvement in renal function. A high index of suspicion for catheter sepsis should be maintained in patients with tunneled right atrial catheters presenting with subacute renal failure.

Aged↗
PubMedDate not supplied

Advances in noninvasive screening for renovascular disease.

BACKGROUND: Nearly 50 million Americans have hypertension, and renovascular hypertension accounts for perhaps 1% of them. PURPOSE: To review the current recommendations and the available screening tests for renovascular hypertension. SUMMARY: The presence of clinical clues increases the predictive value of screening tests for renovascular hypertension; these include abrupt onset of hypertension before age 30 or after age 55, severe hypertension, accelerated or malignant hypertension, hypertension refractory to a triple-drug regimen, moderate hypertension with diffuse vascular disease, an epigastric bruit, moderate hypertension with unexplained azotemia, and azotemia induced by an angiotensin-converting enzyme inhibitor. Captopril renography and duplex ultrasonography are clinically useful screening tools, but wide variation in accuracy exists among institutions. Magnetic resonance angiography may emerge as an effective clinical test. CONCLUSIONS: A thorough history and physical examination, coupled with judicious use of available screening technology, can help determine if a patient has renovascular hypertension and may benefit from intervention.

Adult↗