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Biomedical subjects

S F Wallner

Publications and source records attributed to S F Wallner.

23 records · Page 2Linked to original sources
PubMed1977

The effect of serum from uremic patients on erythropoietin.

Serum from patients with chronic renal failure (CRF serum) contains a substance inhibitory to erythropoiesis in vitro. This paper explores the mechanism of the inhibition. Four experiments were performed to evaluate the effects of CRF serum on erythropoietin (EP). In the first 2 experiments, the effect of exposure of EP solutions to CRF serum was evaluated using the plethoric mouse EP assay system and a tissue culture system containing normal dog marrow cells. In the third study, dog marrow cells were preincubated with CRF serum before being stimulated with EP. Finally, EP-dose response curves were constructed in the dog marrow tissue culture system and analyzed using an enzyme kinetic model. The results show no evidence of inhibition or inactivation of EP by CRF serum, although in vitro heme synthesis is clearly depressed in the presence of CRF serum. We conclude that CRF serum inhibits erythropoiesis by directly, although reversibly, impairing the ability of erythroblasts to synthesize heme.

Aged↗
PubMed1977

Splenic sequestration syndrome at mountain altitudes in sickle/hemoglobin C disease.

The splenic sequestration syndrome was observed in five children with sickle/hemoglobin C (S/C) disease in association with a change in altitude. In four of them, it occurred during or immediately following a trip to mountain altitudes greater than 9,000 feet. In the fifth child, the crisis occurred in ten days after travel in a pressurized plane from sea level to Denver. No previous reports of this complication in S/C patients during mountain travel have been noted although the occurrence is known in association with aircraft flights.

Abdomen↗
PubMed1976

The anemia of chronic renal failure and chronic diseases: in vitro studies of erythropoiesis.

The presence of a serum factor in chronic renal failure (CRF) which inhibits erythropoietin-stimulated erythropoiesis was studied, using a technique in which dog marrow cells were stimulated to produce heme in the presence of human serum. In the total series comparing 27 normal sera with 52 CRF sera, less heme was synthesized when the system contained CRF sera (total series, p = 0.0001). There was no evidence of inhibition of heme synthesis by serum from 12 patients with the anemia of chronic diseases (CD). Mixing experiments with normal and CRF sera suggested that this defect in CRF serum was not due to lack of a factor necessary for heme synthesis. Addition of urea, creatinine, and guanidinosuccinic acid to normal serum did not impair its ability to support erythropoiesis in this system. These data demonstrated that serum from patients with CRF contains a material inhibiting erythropoiesis in vitro, We propose that the material is responsible, in part, for the clinically severe anemia seen in these patients.

Adolescent↗
PubMed1975

The anemia of chronic renal failure: in vitro response of bone marrow to erythropoietin.

Bone marrow cells of patients with chronic renal failure were studied in short-term in vitro cultures to determine erythropietin responsiveness. Seven normals and fourtheen patients on hemodialysis were studied. Bone marrow cells of normal subjects and of patients with chronic renal failure responded similarly to erythropoietin. Total heme synthesis was significantly lower in cultures prepared with uremic serum than normal serum. We conclude that there is a substance in the serum of uremic patients which suppresses general heme synthesis and that this "uremic toxin" may be responsible, in part, for the clinically severe anemia seen in these patients.

Adult↗