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Biomedical subjects

C S Brooks

Publications and source records attributed to C S Brooks.

At least 19 recordsLinked to original sources
PubMed1989

Cost effectiveness and accuracy of renal scans in the management of patients undergoing renal transplantation.

Following renal allograft transplantation, renal scans are frequently performed to evaluate anatomical and functional causes for allograft dysfunction. In our retrospective study of 20 patients, renal scans were found to be more expensive compared to renal biopsies $68,688 vs $7,421, and, in only one patient was aggressive anti-rejection therapy instituted based solely on the renal scan results. The 95% confidence interval for the proportion of correct diagnosis by renal scan was 0.16 to 0.62.

Adult↗
PubMed1988

Systemic mastocytosis associated with membranous nephropathy and peripheral neuropathy.

A report of the occurrence of membranous nephropathy and peripheral neuropathy in a patient with systemic mastocytosis is presented. Previous reviews of patients with systemic mastocytosis have not noted this association. During cyclical therapy with prednisone and chlorambucil in this case, nephrotic-range proteinuria remitted. Peripheral neuropathy resolved 10 months after discontinuation of therapy. Pathophysiological mechanisms resulting in this clinical presentation may be immunologically mediated.

Demyelinating Diseases↗
PubMed1985

Nutrition in renal transplantation.

This study was conducted to determine whether a high-nitrogen, low-carbohydrate diet in the immediate post-operative renal transplant period could result in a positive nitrogen balance and fewer cushingoid side effects. Twelve consecutive nondiabetic renal transplant recipients were randomly assigned to the isocaloric control or experimental diet group. The six patients ingesting the experimental diet achieved positive nitrogen balance whereas five of the six patients on the control diet had a negative nitrogen balance. The nitrogen balance varied directly and proportionately with the protein intake. Potassium balance mirrored the nitrogen balance data. Cushingoid side effects did not develop in any of the six experimental diet patients whereas four of the six control diet patients had evidence of severe cushingoid appearance and two had moderate cushingoid appearance (P = .01). Based upon the findings of this study, we suggest that the renal transplant recipient's diet could be altered to provide more protein and less carbohydrate to improve nitrogen balance and prevent cushingoid features. It is possible that a high-protein, low-carbohydrate diet may be used by additional patients taking steroids for other disease states to prevent cushingoid side effects and improve nitrogen balance.

Adult↗
PubMed1985

Pulmonary hemodynamics in systemic hypertension.

We reviewed cardiac catheterization data and the medical records of 30 patients with systemic hypertension to establish their pulmonary hemodynamic profiles and the relationship between certain clinical and demographic variables and increased pulmonary vascular resistance. Mean systemic arterial pressure ranged from 110 to 210 mm Hg, and systemic vascular resistance ranged from 17.6 to 47.0 units. Seven patients had normal pulmonary wedge pressure and normal pulmonary vascular resistance, one had elevated pulmonary wedge pressure and normal pulmonary vascular resistance, five had elevated pulmonary wedge pressure and increased pulmonary vascular resistance, and 17 had normal pulmonary wedge pressure and increased pulmonary vascular resistance. There were significant positive correlations between systemic vascular resistance and pulmonary vascular resistance and between mean systemic arterial pressure and mean pulmonary artery pressure, but there was no correlation between mean pulmonary wedge pressure and pulmonary vascular resistance. Of the 17 patients with normal pulmonary wedge pressure and increased pulmonary vascular resistance, seven had clinical or radiologic evidence of prior left ventricular failure. We conclude that increased pulmonary vascular resistance occurs commonly in patients with systemic hypertension. Although some cases of increased pulmonary vascular resistance relate to active or preexistent left ventricular failure, the majority remain unexplained, suggesting that neurohumoral or other factors may produce a hypertensive response in both the systemic and pulmonary arterial circuit.

Adult↗
PubMed1985

Nortriptyline-induced severe hyperventilation.

A 61-year-old man with end-stage renal disease developed severe hyperventilation following nortriptyline hydrochloride usage for depression. He required mechanical ventilation and paralysis to correct severe respiratory alkalosis. To our knowledge, nortriptyline usage has not been previously associated with hyperventilation.

Alkalosis, Respiratory↗
PubMed1982

Renal function studies in man with advanced renal insufficiency.

In subjects with advanced renal insufficiency, the average of the creatinine and urea clearances ([Ccr + Cur]/2) is frequently used as an indicator of glomerular filtration rate (GFR). To test the accuracy of this method, 31 subjects with inulin clearance (Cin) less than 20 ml/min/1.73 m2 underwent simultaneously timed creatinine, urea, and inulin clearances. The results indicated that: (1) Ccr correlated positively with Cin; mean fractional excretion of creatinine (Ccr/Cin) was 1.5; (2) Cur correlated positively with Cin; in contrast to creatinine, the fractional excretion of urea (Cur/Cin) correlated negatively with Cin; (3) in 10 of 12 subjects with Cin less than 8 ml/min 1.73 m2, the Cur/Cin was greater than 1, suggesting that tubular secretion may have occurred; and (4) the (Ccr + Cur)/2 correlated positively with Cin and was the best clinical indicator of GFR.

Adult↗
PubMed1982

Clinical appraisal of creatinine clearance as a measurement of glomerular filtration rate.

The plasma creatinine and the endogenous creatinine clearances are two of the most commonly used tests in clinical medicine to assess glomerular filtration rate. However, the contribution that tubular secretion of creatinine has on the total endogenous creatinine clearance (Ccr) is not generally known, nor are the effects renal insufficiency has on the tubular secretion of creatinine. To assess the above, 123 human subjects, with a wide range of renal function, underwent simultaneous Ccr and inulin clearances (Cin). The results indicate that: (1) Ccr approximates Cin only when Cin is normal; (2) a normal plasma creatinine of Ccr is not measurable evidence of a normal Cin; and (3) with progressive decline in Cin, there is progressive increase in the tubular secretion of creatinine, leading to a progressive disparity between Ccr and Cin.

Adult↗
PubMed1982

Body-fluid composition in normal and hypertensive man.

1. Erythrocyte mass, plasma volume (PV), extracellular fluid volume (ECFV) and total body water were simultaneously measured in 30 normotensive and 30 normal-renin hypertensive Caucasian male subjects for accurate determination of the presence or absence of a disorder(s) in body-fluid composition in hypertension. 2. The results indicate that plasma volume and total blood volume are lower in hypertensive subjects than in normotensive control subjects. The PV comprised 19% of the ECFV in both control and hypertensive subjects. 3. ECFV was lower in hypertensive subjects than in normotensive control subjects; the PV and interstitial fluid components of the ECFV were reduced by similar proportions. The ECFV, furthermore, comprised a smaller portion of the total body water in hypertensive subjects than that in control subjects. 4. We conclude that in the hypertensive state there is a reduction in the ECFV, but that there is no change in the partition of the ECFV between the plasma and interstitial components.

Adult↗
PubMed1982

Renal function and hemodynamic studies in low- and normal-renin essential hypertension.

Reduced renal blood flow has been suggested to be both a cause and a consequence of essential hypertension. To test these hypotheses, techniques for the clearance of inulin (Cin) and p-aminohippurate (Cpah) were used to assess renal function and hemodynamic measurements in patients with mild and moderate normal-renin and low-renin essential hypertension and in age-matched normotensive subjects. In our study, compared with age-matched control subjects, normal-renin hypertensive subjects younger than 42 years with basal diastolic BPs less than 100 mm Hg had normal glomerular filtration (Cin) and effective renal plasma flow (Cpah), filtration fraction (Cin/Cpah), and renal blood flow (Cpah/1-hematocrit value). The mean arterial pressure (MAP) and renal vascular resistance (MAP/renal blood flow) were increased. In contrast, compared with age-matched control subjects, normal-renin hypertensive subjects older than 42 years with basal diastolic BPs less than 100 mm Hg and greater than 100 mm Hg had a decreased Cpah and an increased filtration fraction. The MAP was increased, the renal blood flow decreased, and the renal vascular resistance notably increased. Subjects with low-renin essential hypertension had renal function and hemodynamic patterns indistinguishable from those of age matched normal-renin hypertensive subjects with similar basal diastolic BPs. These data suggest that in early normal-renin essential hypertension, the increase in systemic BP is not caused by renal circulatory disturbances. Increased renal vascular resistance, however, may lead to subsequent vascular functional or structural changes, ultimately decreasing effective renal plasma flow but at a rate disproportionate to the glomerular filtration rate.

Adult↗
PubMed1981

Effects of diuretic and propranolol on plasma lipoprotein lipids.

Ticrynafen (TCNF), a nonthiazide diuretic, has been reported to be nonhyperlipidemic. To define the effects of these drugs on plasma lipoproteins, experiments were performed in hypertensive subjects after placebo therapy, 4 wk after therapy with either hydrochlorothiazide (HCTZ) or TCNF, 3 mo after diuretic with propranolol, and 1 mo after therapy with propranolol alone. Plasma lipoproteins were separated by ultracentrifugation and the lipid fractions isolated by extraction and silicic acid thin-layer chromatography. Plasma low-density lipoprotein (LDL) total cholesterol fell and high-density lipoprotein (HDL) total cholesterol rose in subjects receiving TCNF. TCNF had no effect on plasma low-density lipoprotein (VLDL) triglyceride or phospholipid. There was no significant changes in LDL or HDL total cholesterol in subjects on HCTZ. HCTZ tended to increase plasma VLDL triglyceride and phospholipid. The addition of propranolol to either diuretic had no effect on LDL or HDL total cholesterol but increased VLDL triglyceride, especially in subjects on HCTZ. Propranolol alone had no effect on any of the lipids measured.

Adult↗
PubMed1981

Body fluid composition in chronic renal failure.

Studies were performed to assess body fluid composition alterations occurring in 10 patients undergoing chronic hemodialysis. Red cell mass (RCM), plasma volume (PV), extracellular fluid volume (ECF), and total body water (TBW) were assessed 24 hours following hemodialysis to dry weight, following infusion of normal saline to increase body weight by approximately 2 kg, and following hemodialysis to decrease body weight by approximately 2 kg. Results demonstrate that TBW constituted from 48.5 to 51.0% of body weight. The ECF constituted from 41.8 to 46.3% of the total body water. The ratio of PV to interstitial fluid (ISF) volume (ISF = ECF - PV) approximated 1.1 to 1.2:3. Salt and water alterations (isotonic saline infusion and ultrafiltration) were restricted to the ECF component of the TBW. In the ECF, it was principally the ISF that buffered salt and water expansion or depletion. There was no evidence for volume alterations in the intracellular fluid (ICF = TBW - ECF). We conclude that the ISF is the buffer zone which maintains the proper balance and relationship between vascular capacity and volume.

Adult↗
PubMed1979

Volume studies in men with mild to moderate hypertension.

The importance of salt and water in the pathophysiology of the hypertensive state is well recognized. The current study is the first to report simultaneous measurements of red blood cell mass, plasma volume, extracellular fluid and total body water levels. Studies were performed in 82 white men, 14 with normal blood pressure and 16 with low renin and 52 with normal renin hypertension. The results indicate that subjects with normal renin hypertension compared with age-matched controls are characterized by an absolute increase (1.5 liter/m2) in intracellular fluid (total body water minus extracellular fluid). Furthermore, the ratio of extracellular fluid to total body water is decreased (0.43 to 0.38). No volume differences were found between subjects with low renin hypertension and age-matched subjects with normal renin hypertension. We conclude that subjects with normal renin hypertension compared with age-matched peers are characterized by an expanded intracellular fluid and that subjects with low renin hypertension do not exhibit a unique volume disorder.

Adult↗
PubMed1979

Comparative effects of ticrynafen and hydrochlorothiazide on blood pressure, renal function, serum uric acid and electrolytes, and body fluid spaces in hypertensive man.

25 hypertensive subjects underwent a double-blind, randomized study to compare the effects of ticrynafen (TCNF) with hydrochlorothiazide (HCTZ) on blood pressure (BP), renal function, serum uric acid (UA) and electrolytes, and body fluid spaces. BP was similarly lowered by TCNF and HCTZ. Neither TCNF nor HCTZ had a significant effect on true or regular creatinine, inulin, or PAH clearances. TCNF lowered UA, whereas HCTZ elevated UA. Both produced similar electrolyte disturbances. Neither TCNF nor HCTZ, according to our methods, had a significant effect on plasma volume, extracellular fluid, or total body water. The primary advantage of TCNF compared with HCTZ is its profound hypouricemic effect.

Adult↗
PubMed1979

Pulmonary hemodynamics in systemic hypertension. Long-term effect of minoxidil.

To assess the effect of minoxidil on pulmonary hemodynamics, we performed cardiac catheterization on ten patients, prior to the administration of minoxidil, at six months after its addition to their existing drug regimens, and on seven patients following 12 or more months of minoxidil therapy. Systemic blood pressure and systemic vascular resistance were significantly reduced at six months and following 12 or more months of minoxidil therapy. Before receiving minoxidil, nine of ten patients had elevated pulmonary vascular resistance. There were no significant changes in pulmonary vascular resistance following the initiation of minoxidil. The data suggest that pulmonary hypertension is common in patients with long-standing poorly controlled systemic hypertension, and that minoxidil, in doses sufficient to significantly reduce systemic blood pressure, does not cause or aggravate pulmonary hypertension.

Adult↗
PubMed1977

Diuretic therapies in low renin and normal renin essential hypertension.

This study was designed to compare the effectiveness of spironolactone, hydrochlorothiazide, and combined spironolactone-hydrochlorothiazide therapy in patients with low renin and those with normal renin essential hypertension. Patients with low renin hypertension had a greater hypotensive response to each regimen (p less than 0.001). Low renin patients responded equally to both spironolactone and to hydrochlorothiazide, and in low renin but not in normal renin patients reduction of blood pressure correlated with weight loss. These results suggest that a volume factor, not specifically related to increased mineralocorticoid production, contributes to the pathogenesis of low renin essential hypertension.

Adult↗