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Biomedical subjects

J O Wells

Publications and source records attributed to J O Wells.

12 recordsLinked to original sources
PubMed1994

Reduced generalization following preexposure: latent inhibition of common elements or a difference in familiarity?

Rats injected with lithium chloride after drinking a saline-lemon solution also reduced their consumption of saline-lemon and sucrose-lemon, but a single prior exposure to sucrose-lemon decreased the generalized aversion. Experiment 1 showed that this decrease in the aversion to sucrose-lemon could not be explained by a decrease either in the aversion conditioned to saline-lemon or in neophobia to sucrose-lemon. Experiment 2 ruled out the possibility that generalization between saline-lemon and sucrose-lemon was based on shared novelty. Experiment 3 showed that generalization between the two solutions was related to the strength of the aversion to the lemon flavor they shared in common and that prior exposure to sucrose-lemon reduced generalization by causing latent inhibition of this common element.

Animals↗
PubMed1986

High-carbohydrate diet: antinatriuretic and blood pressure response in normal men.

The hypothesis that high-carbohydrate feeding leads to increased insulin secretion, sodium retention, and elevation in blood pressure was examined in seven healthy men. A baseline 7-day balance study on low (13%) or high (52%) carbohydrate was followed by a 2-wk balance on the alternate diet and a 1-wk balance on the baseline diet. Results indicated that changing carbohydrate intake caused a rapid (2-3 day) inverse change in urinary sodium excretion and balance. By the second week, however, urinary-sodium level returned to baseline accompanied by an inverse change in plasma aldosterone. No significant rise in blood pressure was detected throughout the study. High-carbohydrate feeding promotes sodium retention in normal subjects, but the effect is counterregulated by a reduction in plasma aldosterone. A high-carbohydrate diet in healthy subjects does not cause a significant short-term increase in blood pressure.

Aldosterone↗
PubMed1986

Mesangial glomerulonephropathy with decreased circulating C4 and predominant mesangial C4 deposition in association with one null gene at the C4B locus.

We report a case of mesangial glomerulonephropathy associated with decreased circulating C4 in a young man with recurrent microscopic hematuria and one null gene at the C4B locus. Mesangial deposits moderately reactive with anti-C4 and weakly reactive with anti-C3 and anti-IgA were found on renal biopsy. No evidence was found to support a diagnosis of IgA nephropathy or any other of the recently described mesangial glomerulonephropathies with immunoglobulin and complement deposition. This case apparently represents a unique, heretofore undescribed variant of mesangial glomerulonephropathy associated with mesangial C4 deposition and C4 hypocomplementemia.

Adolescent↗
PubMed1985

Concomitant renal revascularization in patients undergoing aortic surgery.

Sixty-three patients who underwent renal revascularization at the time of aortic surgery were retrospectively reviewed. These patients had significant renal artery stenosis in addition to either severe aortoiliac occlusive disease or aortic aneurysmal disease. Fifty-eight patients were hypertensive, whereas five patients were normotensive and these renal lesions were treated prophylactically. The operative mortality rate was 3%. Despite lack of selectivity in these patients with diffuse atherosclerosis, 60% (35 of 58) of the patients with hypertension could be classified as either "cured" or "improved." Patients with bilateral renal artery involvement and moderate azotemia were noted to improve with respect to renal function postoperatively. No patient has required chronic dialysis at a mean follow-up period of 22.6 months. Simultaneous aortic and renal artery surgery may be performed with low morbidity and mortality rates and produce a gratifying improvement in hypertension. Renal functional improvement and perhaps preservation of renal mass may be anticipated in selected patients.

Adult↗
PubMed1985

Percutaneous angioplasty in clinical management of renovascular hypertension: initial and long-term results.

Between January 1980 and July 1983, percutaneous transluminal angioplasty was attempted on 137 stenotic renal arteries in 100 patients. At termination of follow-up studies (3-39 months, mean of 16 months), 70% of those treated for hypertension had benefited from the procedure. Stenosis secondary to fibromuscular dysplasia responded better than stenosis from arteriosclerosis (85% and 65% of the patients, respectively). Benefit was minimal for those with stenosis of the renal artery ostium or renal insufficiency. Determining levels of renal vein renin before angioplasty is helpful in selecting patients; following angioplasty, this has considerable significance in predicting the success of the procedure.

Adult↗
PubMed1983

Primary hyperparathyroidism and hypertension.

A causal relationship between hyperparathyroidism and hypertension has been presumed to exist. In order to determine the nature of any such relationship, 50 patients with primary hyperparathyroidism and diastolic hypertension undergoing surgical correction of hypercalcemia (study group) were compared to 50 matched eucalcemic patients with diastolic hypertension of similar magnitude undergoing equivalent elective surgery (control group). There were no significant differences in average preoperative diastolic pressures, average postoperative diastolic pressures, or the magnitude of early postoperative reduction in diastolic pressure between the study and control groups (P greater than 0.05). Bed rest may play a significant role in the early postoperative reduction in blood pressure frequently observed in patients undergoing correction of hyperparathyroidism.

Blood Pressure Determination↗
PubMed1980

Unusual cases of resistance to minoxidil therapy.

Minoxidil was used to treat 112 patients with severe and refractory hypertension during a period of 8 years. The drug was highly effective and resistant cases were distinctly unusual. We reported here 4 such cases. In 2, the patients showed no response to large doses, even when minoxidil was combined with other drugs. In the third, a patient with severe gastrointestinal abnormalities could not retain the drug. No proof exists that if it had been given parenterally it would not have been effective. The last case is of a patient with obstructive cardiomyopathy (IHSS) who reponded well to minoxidil. Because of the vasodilator's profound effect on the cardiovascular system, changes in this patient's hemodynamics occurred which made fluid retention and cardiomegaly intolerable. Patients with severe obstructive cardiomyopathy should be considered for therapy with a strong vasodilator only with caution and with the awareness that fluid retention may be disproportionately large.

Adult↗
PubMed1975

Changing surgical indications in azotemic secondary hyperparathyroidism.

It would appear that the initial enthusiasm for surgery in azotemic secondary hyperparathyroidism was unsupported by conclusive data, but that a therapeutic alternative recommending surgical abstinence represents an equally extreme position, particularly since the long-term effects of sustained mild hyperparathyroidism are unknown. The proper course at present for the patient's best interests might best be described as selective. Final resolution of conditional therapy in azotemic hyperparathyroidism awaits the completion of objective studies.

Adult↗
PubMedDate not supplied

Effects of therapeutic paracentesis on systemic and hepatic hemodynamics and on renal and hormonal function.

Thirteen patients with cirrhosis and tense ascites (six with and seven without peripheral edema) underwent 4- to 15-liter paracentesis without intravenous "colloid" replacement. Cardiac output increased from 6.6 +/- 0.7 liters per min at baseline to 8.2 +/- 0.7 liters per min (p less than 0.003) 1 hr after large-volume paracentesis completion and fell to 7.5 +/- 0.69 liters per min (p less than 0.05 vs. baseline, p less than 0.02 vs. 1 hr) 24 hr after large-volume paracentesis completion. There was no change in mean arterial pressure or mean pulmonary artery pressure. Central venous pressure fell from 9.1 +/- 0.8 mm Hg at baseline to 8.6 +/- 1.4 mm Hg 1 hr post-large-volume paracentesis to 6.8 +/- 1.0 mm Hg (p less than 0.005 vs. baseline, p less than 0.02 vs. 1 hr value) at 24 hr, and pulmonary capillary wedge pressure fell from 13.1 +/- 0.9 to 11.1 +/- 1.3 mm Hg 1 hr after large-volume paracentesis and to 9.89 +/- 1.2 (p less than 0.01 vs. baseline, p less than 0.03 vs. 1 hr after large-volume paracentesis) at 24 hr. Heart rate fell from 90 +/- 3.0 to 85 +/- 2.9 beats per min (p less than 0.01) 1 hr after large-volume paracentesis completion, but increased to 89 +/- 2.5 beats per min (p less than 0.02 vs. 1 hr after large-volume paracentesis) at 24 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Renal vein renin analysis: limitations of its use in predicting benefit from percutaneous angioplasty.

Two hundred forty-four consecutive patients (mean age 61 years), including 123 who had technically valid renal vein renin (RVR) analysis and 121 without RVR data, underwent technically successful percutaneous renal artery angioplasty (PTRA). They were retrospectively examined to evaluate the utility of RVR analysis in identifying renal hypertension (RVH), predicting benefit from PTRA, and determining if the lack of knowledge of renin levels significantly affected clinical outcome after PTRA. Abnormal RVR values were associated wtih clinical benefit after PTRA in 62 of 93 patients (67% sensitivity, 20% specificity, 72% positive predictive value). Clinical improvement following PTRA occurred in 31 of 37 patients with normal pre-PTRA RVR values (16% negative predictive value). RVR analysis correctly identified 86 of 117 patients with renovascular hypertension (74% sensitivity, 16% negative predictive value). Improved blood pressure (BP) control occurred in 72% with abnormal RVR analysis and 66% of the 121 patients without RVR data (p > 0.1). We conclude that the very low negative predictive value significantly limited the use of RVR analysis in this elderly (mean age 60 years) patient population with a high incidence of mild renal functional impairment (mean serum creatinine 1.4 mg/dl) and bilateral renal artery stenosis (38%). The lack of pre-PTRA renin data did not significantly affect clinical outcome. If RVR data were relied upon as the exclusive selection criterion in patients of this type, many would be prevented from having the benefit of cure or improvement by PTRA.

Angioplasty, Balloon↗