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Biomedical subjects

P Hirszel

Publications and source records attributed to P Hirszel.

At least 55 records · Page 3Linked to original sources
PubMed1976

Uremic autonomic neuropathy: evaluation of ephedrine sulphate therapy for hemodialysis-induced hypotension.

The hemodynamic response to ephedrine sulphate were studied in a patient on maintenance hemodialysis therapy with chronic renal failure due to renal amyloidosis. The evaluation (including cardiac catheterization studies) and estimation of responses to Valsalva maneuvers before and after ephedrine administration documented the diagnosis of autonomic insufficiency. Oral ephedrine failed to influence the episodes of severe dialysis-induced hypotension. Also the patient did not benefit from the infusion of Aramine. These studies suggest that catecholamine stores of adrenergic nerves may be depleted in uremic patients with clinical signs of autonomic neuropathy.

Blood Pressure↗
PubMed1976

Peritoneal clearances in scleroderma and diabetes mellitus: effects of intraperitioneal isoproterenol.

Reduced peritoneal clearances of creatinine and urate were demonstrated repeatedly in a patient with scleroderma and a patient with diabetes mellitus. Urea clearances were not significantly different from usual values. The findings suggest decreased peritoneal membrane permeability and/or area (if urea clearance is flow limited). Clearances increased to usual values with intraperitioneal isoproterenol in the patient with diabetes. There was no effect of isoproterenol in the patient with scleroderma.

Adult↗
PubMed1975

Influence of peritoneal dialysis on factors affecting oxygen transport.

To determine the effect of changing concentrations of uremic metabolites on factors affecting oxygen transport, without the effects of extracorporeal blood pumping, we studied five patients before, during and after peritoneal dialysis. Significant decreases in serum urea, creatinine and phosphate and increase in serum bicarbonate were not associated with changes in P50, a reflection of hemoglobin-oxygen affinity. High erythrocyte 2,3-DPG concentrations decreased only slightly. Arterial pO2 increased slightly as negative fluid balance was achieved. The slight changes in oxygen transport parameters with dialysis suggest an interplay of compensatory factors and do not warrant modifying dialysis to limit the correction on acidosis or hyperphosphatemia. Effects on hemoglobin and pO2 resulting from fluid loss can be the dominant influence of peritoneal dialysis on tissue oxygenation.

Creatinine↗
PubMed1975

Effect of hemodialysis on factors influencing oxygen transport.

Ten patients underwent 4 study hemodialyses, one with standard dialysis conditions, one with an isophosphate dialysate, one with simultaneous ammonium chloride loading, and other, after pretreatment, with sodium bicarbonate. Measurement of hemoglobin oxygen affinity (P-50), erythrocyte 2,3-DPG, blood-gasses, and serum chemistries revealed biochemically effective hemodialyses and slight changes in oxygen transport parameters. The P-50 (in vivo) values decreased slightly but significantly (p greater than 0.05) with dialysis. When corrected to pH 7.4, eliminating the Bohr effect, P-50 increased (p greater than 0.05). With unmodified dialysis elevated values of 2,3-DPG (in comparison to normal) decreased, a change that did not correlate with delta-p-50, delta-serum phosphate, or delta-serum creatinine. With standard and isophosphate dialyses Po-2 decreased significantly. The decrease correlated with delta-hydrogen ion concentration and did not occur with dialyses designed to maintain pH constant. Thus, hemodialysis influences many factors that affect oxygen transport in different and counterbalancing directions. These changes are not totally explained by alterations in 2,3-DPG, pH or serum phosphate. Maintenance of acidosis or hyperphosphatemia during dialysis is not recommended.

Adolescent↗
PubMedDate not supplied

Splanchnic volume, not flow rate, determines peritoneal permeability.

To distinguish the effects of splanchnic blood flow rate from those of splanchnic volume on peritoneal transfer rates, measurements were made in rabbits before and after intraperitoneal exposure to sodium chromate. The sodium chromate induced reversible hepatic sinusoidal block with consequent portal venous congestion and stasis, which was demonstrable on histologic sections. Concurrently the ultrafiltration rate, and ultrafiltration coefficient each doubled after chromium even though the dialysate reabsorptive rate increased and the absorptive diffusion of glucose was at least as high as in control dialyses. Chromium induced significant increases in mass transfer coefficients of urea, potassium and phosphate and in protein clearance. These data suggest that splanchnic volume is an important determinant of peritoneal transfer functions and that the hepatic capillaries may contribute appreciably to transfer ordinarily ascribed to peritoneal capillaries alone.

Animals↗
PubMedDate not supplied

Low-protein diet suppresses serum insulin-like growth factor-1 and decelerates the progression of growth hormone-induced glomerulosclerosis.

A low-protein (LP) diet has been associated with amelioration of renal function in glomerulosclerosis (GS). However, the mechanisms involved are still unclear. We have used a mouse transgenic for bovine growth hormone (GH), which develops progressive GS and exhibits consistently elevated levels of circulating GH and insulin-like growth factor (IGF)-1, to study the effect of dietary protein restriction. LP (6% protein) and normal-protein (NP, 20% protein) diets were maintained for 30 weeks in mice with established GS of mild/moderate degree. The degree of GS was markedly attenuated in LP compared to NP mice. Quantitative analysis revealed a significantly lower GS index (1.4 +/- 0.9 in LP vs. 2.8 +/- 0.8 in NP) and glomerular volume (0.8 x 10(6) +/- 0.1 x 10(6) microm(3) in LP vs. 1.2 x 10(6) +/- 0.1 x 10(6) microm(3) in NP) in mice with restricted protein intake. These morphologic changes were accompanied by a significant reduction in renal expression of alpha(1) type-IV collagen (2.4-fold) and tenascin (1.4-fold) in LP mice. Serum IGF-1 decreased by 40% and showed a significant correlation with alpha(1) type-IV collagen expression with the LP diet. The present finding supports the use of the LP diet to decelerate the progression of GS and furthermore suggests that one of the mechanisms involved in this process is the GH/IGF-1 regulation by protein intake.

Animals↗