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Biomedical subjects

J P Naets

Publications and source records attributed to J P Naets.

At least 19 recordsLinked to original sources
PubMed1986

Radioimmunoassay of erythropoietin in chronic uraemia or anephric patients.

The erythropoietin (Ep) plasma titre of 41 anaemic patients with normal renal function or with renal insufficiency (with or without kidney) was measured by RIA and compared to values observed with the polycythaemic mouse assay. A good correlation was found with both methods (r = 0.88). However, about 20% of samples gave higher values with the bioassay. 21 Ep titres measurable by the bioassay ranged from 40 to 4400 mU (mean 717.1 mU) compared to 14.8 to 3788 mU (mean 484.7 mU) measured by the RIA. Low levels of Ep plasma titre have been observed in patients with renal insufficiency and no difference was found between nephric uraemic patients and the anephric group. These results suggest that the increased blood requirements in anephrics are not due to a smaller production of Ep, but ultimately to the presence of an inhibitor of erythropoiesis. The well-known inverse relationship between haematocrit and Ep level was not found in renal insufficiency. However, some humoral regulation of erythropoiesis seems to persist in these patients since the elevation of red blood cells by transfusions was followed by a decrease of the Ep level.

Biological Assay↗
PubMed1980

Transient IgA-lambda paraproteinemia during treatment of acute myelomonoblastic leukemia.

Monoclonal plasma cell proliferation with secretion of IgA-lambda and free lambda light chains during a phase of bone marrow aplasia following intensive chemotherapy was observed in a patient suffering from acute myelomonoblastic leukemia. The clonal expansion and regression was investigated at the cellular level by immunofluorescence using an antiserum against the idiotype of the paraportein. Although a large panel of common antigens was used for testing, no antibody activity of the paraprotein could be demonstrated.

Aged↗
PubMed1979

Osteogenesis imperfecta associated with multiple myeloma.

In a case of osteogenesis imperfecta with multiple fractures already from childhood, myelomatosis was diagnosed at the age of 52 years because of a serum M-component (IgG, lambda), Bence Jones proteinuria, myeloma cells in the bone marrow, and osteolytic skeletal lesions. She died 10 months later. A partial postmortem examination of a larger bone lesion confirmed the diagnosis.

Bone Neoplasms↗
PubMed1977

Polycythaemia and erythropoietin producing uterine fibromyoma.

A case of polycythaemia secondary to uterine fibromyoma is reported. Polycythaemia disappeared after hysterectomy. Erythropoietic activity was detected in the cyst fluid of the tumour. Plasma and urine contained no erythropoietic factor. Polycythaemia was related to erythropoietinlike material produced by the tumour.

Erythropoiesis↗
PubMed1977

Cytogenetic evidence of clonal evolution in 5q- anemia.

The clinical homogeneity of myeloproliferative syndromes associated with a 5 q- marker can be contested, but nevertheless finds support in the 2 case reports we have cited. One of these observations of refractory anemia with partial myeloblastosis and 5 q- marker has shown a transformation into an acute myelomonocytic leukemia with clonal chromosomal evolution.

Aged↗
PubMed1977

Compared effects of irradiation and cyclophosphamide induced erythroid aplasia on the catabolism of exogenous erythropoietin.

The effect of erythroid aplasia on the clearance rate of exogenous erythropoietin from the circulation has been studied in irradiated (200, 400 and 800 r) and cyclophosphamide (50 mg/kg) treated rats. After irradiation, the T1/2 was increased from 1.5 h in controls to 2.3 h. In spite of similar aplasia, the T1/2 observed after cyclophosphamide administration was identical to the T1/2 in controls. These results suggest that the action of X-rays on the catabolism of erythropoietin is independent of erythroid aplasia and could be related to an extramedullary effect of irradiation.

Anemia, Aplastic↗
PubMed1976

Specificity of the 5q-chromosome in a distinct type of refractory anemia.

A further instance of the 5q-chromosome associated with a distinct type of aregenerative anemia strengthened the hypothesis of specificity and consistency of this karyotypic abnormality in a new hematologic entity. The Giemsa banding technique revealed that the deletion of the long arms of chromosome number 5 was interstitial: del (5) (pter leads to q12 : : q31 leads to qter).

Aged↗
PubMed1975

Hematologic disorders in renal failure.

Anemia is a frequent complication of renal failure. As in anemias of other origin, the resulting tissular hypoxia is partially compensated by an increased production of 2,3-diphosphoglycerate in red cells and a shift to the right of the oxygen hemoglobin dissociation curve. Two mechanisms are implicated in this anemia: increased hemolysis and depressed production of red cells. Decreased production of erythropoietin is probably the cause of reduced erythropoiesis, but the role of uremic intoxication has not been unequivocally excluded. In the course of chronic hemodialysis, iron deficiency anemia and occasionally hypersplenism develop. It is noteworthy that blood requirements in anephric patients are two to three times greater than those of nonanephric hemodialyzed patients. Accordingly, bilateral nephrectomy should be restricted to carefully selected cases. At the present time, androgens seem to be the best treatment of renal anemia. Qualitative anomalies of platelets are the main factor responsible for uremic bleeding and are corrected by hemodialysis.

Anemia↗