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Biomedical subjects

J H Bauer

Publications and source records attributed to J H Bauer.

At least 109 records · Page 6Linked to original sources
PubMed1981

Primary necrotizing arteritis of the main renal artery presenting as accelerated renovascular hypertension.

Presented is a unique case of accelerated hypertension in a 26-year-old black man. Clinically, the patient was found to have a left renal artery lesion and lateralizing renal vein renins. At surgery, a stenosing lesion was found in the artery supplying the upper pole of the left kidney. This was caused by a densely fibrotic mass involving the main renal artery. Microscopy revealed a necrotizing arteritis with no other arteries involved. This case of primary necrotizing arteritis of the main renal artery appears to represent a new entity because of its pathological and clinical differences with the known forms of large vessel arteritis. It is possible that this may represent a particularly acute and necrotizing stage of Takayasu's aortitis, or an extremely rare case of classical periarteritis nodosa confined solely to the main renal artery. The renin tissue assays document the hyperreninemia produced by arterial stenosis. The differential diagnosis of the lesion is considered, and the pathophysiology of hypertension due to large vessel arteritis is discussed.

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↗
PubMed1980

Rapid reduction of severe hypertension with minoxidil.

Five patients presenting with severe hypertension who failed to exhibit diastolic blood pressures less than 120 mm Hg following the oral administration of propranolol (60--80 mg) and furosemide (40 mg) received minoxidil (20 mg, p.o.). Systemic blood pressure, heart rate, and cardiac output were measured prior to and hourly following the addition of minoxidil to the regimen of propranolol and furosemide. One hour following the addition of minoxidil, systemic blood pressure decreased from 204/126 to 186/114 mm Hg (mean systolic/mean diastolic blood pressure). Four hours after minoxidil administration, systemic blood pressure was 175/105 mm Hg. Four of the 5 subjects exhibited diastolic blood pressures greater than 100 mm Hg at 4 hr and were given a booster dose of minoxidil (5--20 mg). Systemic blood pressure subsequently decreased to 153/92 mm Hg at 8 hr and to 142/86 mm Hg at 12 hr following the initial dose of minoxidil. The reduction of systemic blood pressure was achieved without significant change in heart rate or cardiac output. These data indicate that stepped-care therapy utilizing a diuretic, a beta-blocking agent, and minoxidil produces prompt, significant, and sustained reduction of systemic blood pressure in patients with severe, potentially life-threatening hypertension.

Adult↗
PubMed1979

Propranolol in human plasma and breast milk.

To assess the problem of continuing propranolol therapy in a breast-feeding mother, studies were performed to determine simultaneously plasma and breast milk concentrations of propranolol after single dose (40 mg) and continuous dose (40 mg 4 times daily) treatment with this drug. Breast milk and plasma concentrations of propranolol peaked between 2 and 3 hours after dosing. Propranolol concentrations in breast milk were less than 40 and 64 percent, respectively, of peak plasma propranolol concentrations after single dose and continuous dose administration. It was estimated that the maximal cumulative propranolol load to this breast-feeding infant, consuming 500 ml of whole milk, when the mother received 40 mg of propranolol 4 times daily would be 21 microgram/24 hours. This dose is considerably less than the usual therapeutic dose of propranolol for infants.

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

Effect of potassium chloride on plasma renin activity and plasma aldosterone during sodium restriction in normal man.

The present study was designed to evaluate the spectrum of responses of PRA and plasma aldosterone (PAldo) to a range of oral potassium intakes (0 to 300 mEq of potassium chloride per day) in 20 normal human subjects receiving an electrolyte-free diet. Potassium exhibited a dose-dependent natriuretic effect. The results of the PRA studies indicate that normal dietary amounts (50 mEq/day) of potassium chloride do not prevent the increase in PRA with absolute sodium deprivation and that PRA is maximally stimulated on 150 mEq of potassium chloride per day. The rise in PRA is directly correlated with serum potassium concentration. The results of the PAldo studies indicate that potassium chloride deprivation attenuates PAldo increases due to sodium deprivation and that PAldo is maximally stimulated on 150mEq of potassium chloride per day. The rise in PAldo is directly correlated with serum potassium concentration and with PRA. The administration of 300 mEq/day of potassium chloride caused significant hyperkalemia and blunted both PRA and PAldo increases. Our results suggest that potassium chloride has an important role in the regulation of PRA and PAldo, and that only following potassium chloride deprivation is the PRA/PAldo response dissociated.

Aldosterone↗
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↗
PubMed1978

Aldosterone in the exaggerated natriuresis of spontaneously hypertensive rats.

The effect of mineralocorticoid hormones on the urinary responses of spontaneously hypertensive and normotensive rats to oral salt loading was determined. In response to a control salt load, the increase was determined. In response to a control salt load, the increase in urinary sodium excretion by the spontaneously hypertensive rats was significantly greater than that of the normotensive rats [48 +/- 6 (SE) mueq/h vs. 26 +/- 4 mueq/h]. Treatment with spironolactone did not significantly alter the natriuretic response of the spontaneously hypertensive rats (43 +/- 8 mueq/h) to another salt load, but increased the natriuretic response of the normotensive rats (55 +/- 7 mueq/h) to that of the hypertensive rats. D-Aldosterone suppressed the natriuretic response to salt loading of the hypertensive rats to a level which was not significantly different from that of the normotensive rats. Plasma aldosterone concentration was significantly lower in the spontaneously hypertensive rats than in the normotensive rats (18.0 +/- 3.3 and 52.1 +/- 5.2 ng/100 ml, respectively). Neither extracellular fluid volume nor total body water in spontaneously hypertensive and normotensive rats were significantly different. The data support the hypothesis that the exaggerated natriuresis in the spontaneously hypertensive rats is mediated by a relative lack by these rats of aldosterone-mediated distal tubular sodium reabsorption.

Aldosterone↗
PubMed1977

Effects of potassium chloride on plasma renin activity during sodium restriction in normal man.

Previous studies have suggested that large intakes of potassium (K) will suppress plasma renin activity (PRA) in normal man. The effect of more modest intakes of K on PRA is unclear. The present study was designed to compare the PRA in 11 normal volunteers maintained on an electrolyte-free diet (7000 J), with and without the addition of 50 mEq/day of potassium chloride (7000 J + KCl), well within the limits of usual dietary consumption. Control recumbent and 2 hr of upright PRA determinations were made by radioimmunoassay prior to the initiation of either the 7000 J diet or the 7000 J + KCl diet and on the fourth day of the diet, at a time when urinary sodium, K, and chloride excretions were near intakes. Mean (+/- S.E.M.) PRA's are indicated in Table II. There are significant (p less than 0.01) differences between (1) all respective recumbent and upright posture positions and (2) before and after the administration of 7000 J and 7000 J + KCl. However, there are no significant differences between (1) control periods or (2) before and after the addition of KCl to the electrolyte-free diet. We conclude from these studies that K, given in modest amounts, has no inhibiting effect on PRA.

Adult↗
PubMed1976

Oral administration of radioactive sulfate to measure extracellular fluid space in man.

Radioactive sulfate-35 (35S) was administered to eight human subjects intravenously and orally, to compare respective kinetics of distribution. Intravenously administered 35S attained equilibration within 60-90 min. Orally administered 35S attained equilibration within 60-105 min and thereafter achieved plasma activity equivalent to the intravenously administered tracer. Eighty percent or greater of the 35S dose was recovered in the 24-h urine, following either intravenous or oral administration. The mean extracellular fluid space demonstrated less than 9% mean difference between routes of administration. It is concluded that 35S is completely absorbed at tracer doses, and may be administered orally as a reliable substitute for intravenously administered 35S for measuring extracellular fluid space.

Administration, Oral↗
PubMed1975

Simultaneous determination of extracellular fluid and total body water. I.

A method for the simultaneous determination of extracellular fluid volume by radiosulfate-35 and total body water by tritiated water is described. Protein was precipitated from plasma with 10 per cent trichloroacetic acid. Radiosulfate-35 and tritiated water were counted in a dual-channel liquid scintillation spectrometer, using an automatic external standard to correct for quench. The sulfate space was calculated by the isotope dilution principle. Crossover counts contributed by radiosulfate-35 into the tritium channel were subtracted from the total counts in that channel. The tritiated water space was then calculated by the isotope dilution principle. Studies were performed in vitro and in 8 bilaterally nephrectomized rats. In vitro extracellular space by radiosulfate-35 and total body water by tritiated water demonstrated less than 3 per cent variation from the predicted volumes. In the rat, total body water determined with tritiated water demonstrated 4 per cent variation from that determined by desiccation. The method is simple, accurate, reproducible, and readily applicable for use in man and animals.

Animals↗
PubMed1975

Volume studies. II. Simultaneous determination of plasma volume, red cell mass, extracellular fluid, and total body water before and after volume expansion in dog and man.

A method for the simultaneous determination of plasma volume, red cell mass, extracellular fluid volume, and total body water is described. Plasma volume and red cell mass were determined by a standard dual gamma-tracer technique using 125radioiodinated labeled human serum albumin (125RISA) and 51radiochromate-tagged red cells (51Cr-RBC). Extracellular fluid volume and total body water were determined by a dual beta-tracer technique which utilized radiosulfate-35 (35SO4) and tritiated water (THO), respectively. Kinetic studies of each radionuclide in normal and fluid expanded states demonstrated equilibration of 125RISA and 51Cr-RBC in 5 minutes, 35SO4 and THO in 30 minutes. The results of the volume studies in dog and man demonstrated less than 10 per cent variation on repetitive study, and better than 70 per cent accuracy in estimating a known fluid change. This technique will enable a more precise and simplified investigation of the physiology of body fluid volume regulation in health and disease.

Animals↗