[An unknown form of polycythemia? An erythropoietic substance in urine and plasma of a 11-year-old girl with polycythemia].
Explore the source record for details and available documents.
Child↗
SEARCH · PubMed Health
Results for “Polycythemia”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Plasma erythropoietin in polycythemia.
Erythropoietin titers of plasma cannot be used to differentiate polycythemia vera from secondary polycythemia since the limit of sensitivity of our current bioassay technics is 50 mU, considerably higher than levels found in normal subjects and in patients with polycythemia. However, erythropoietin is relatively heat stable, and since abundant plasma is available from therapeutic phlebotomies it is possible to prepare and assay highly concentrated, erythropoietin-containing extracts. In 35 normal subjects, erythropoietin levels ranged from less than 5 mU/ml (the limit of sensitivity) to 18 mU/ml with a mean of 7.8 mU/ml. In 21 patients with proved polycythemia vera, the levels were less than 5 mU/ml in all. In 41 patients with suspected secondary polycythemia or polycythemia of unknown origin, the levels ranged from less than 5 to 3,000 mU/ml. Three of the 11 patients with levels less than 5mU/ml were subsequently shown to have polycythemia vera. These results suggest that this refinement of the routine bioassay for erythropoietin may be of clinical importance in the differential diagnosis of polycythemia.
Erythropoietin↗
Familial and congenital polycythemia in three unrelated families.
Three families with polycythemia inherited through apparently different modes are described. Secondary causes of polycythemia were ruled out. Erythropoietin (EPO) levels were normal or low, even after phlebotomy. In vitro erythroid colony growth in standard assay cultures containing EPO was normal; however, in the absence of added EPO, a few progenitors from most of the affected individuals were able to generate recognizable colonies of mature erythroblasts, although these were smaller and proportionately less numerous than seen in polycythemia vera (PV). To search for EPO-receptor changes as a possible pathophysiologic mechanism, we examined, by Southern blot analysis, genomic DNA samples from affected and nonaffected family members, as well as three patients with PV. Two different probes, derived from the human EPO-receptor, were used. We found no evidence for chromosomal rearrangements or gene amplification in hereditary polycythemia or PV patients. Further, no nucleotide sequences were found that were homologous to the Friend spleen focus-forming virus glycoprotein gp55, which has been shown to bind to and activate the murine EPO-receptor. Functional studies examining number and binding affinity of the EPO-receptor on erythroid progenitors from three hereditary polycythemia patients demonstrated no abnormalities. We conclude that the mechanism(s) for the erythrocytosis in familial and congenital polycythemia and in PV may not involve the EPO-receptor and, therefore, may result from alterations of postreceptor responses.
2,3-Diphosphoglycerate↗
Decreased (Ca2+ + Mg2+)-stimulated ATPase activity in erythrocyte membranes from polycythemia vera patients.
Erythrocytes were hemolyzed in hypotonic phospate buffer containing 0.5 mmol/l Ca2+ and the membranes subsequently washed twice in hypotonic tris buffer. The centrifugation was performed in a continuous flow system, which was necessary to obtain maximal ATPase activity. The Mg2+-dependent Ca2+-stimulated ATPase activity of 14 patients with polycythemia vera was only 67 per cent (P less than 0.001) of the activity of a control material consisting of 10 donors and 11 bank blood specimens. Five patients with secondary polycythemia and four patients with an increased erythrocyte fraction did not differ significantly from the controls. The polycythemia vera patients with the highest leukocyte count showed the lowest ATPase activity. The apparent calcium dissociation constant of the ATPase in polycythemia vera was about 10(-6) mol/l, as in controls. The relation between the reduced ATPase activity and the abnormal hemopoiesis of polycythemia vera patients is discussed.
Adenosine Triphosphatases↗
Hyperlipidemia and myocardial infarction among 118 patients with polycythemia vera.
Hyperlipidemia was reported among 46 of 118 polycythemia vera patients as compared to a control group of 115 healthy subjects in whom hyperlipidemia was reported in 20. Among the 46 hyperlipidemic patients with polycythemia vera 14 had a myocardial infarction, while among the other 72 nonhyperlipidemic polycythemia vera patients myocardial infarction occurred amont 17. Since repeated phlebotomies may induce hyperlipidemia, this form of treatment of polycythemia vera may be potentially dangerous in already hyperlipidemic polycythemia vera patients.
Female↗
Neonatal polycythemia in appropriately grown infants of hypertensive mothers.
Neonatal polycythemia is a frequent finding after pregnancies complicated by diabetes and by maternal hypertension with intrauterine growth retardation (IUGR). It is still unclear if the association of polycythemia with hypertension is the result of IUGR or of hypertension per se. To establish the incidence of neonatal polycythemia in populations at risk, we analyzed the results of hematocrit values obtained from 1592 neonates born consecutively at the Hospital de Clinicas, Buenos Aires. Capillary hematocrit values were obtained by heel stick before 6 h of age. When the values were 65% or greater, new samples were obtained from an antecubital vein. The risk of polycythemia in appropriately grown infants of hypertensive mothers was 12.6-fold greater than the risk in the general population. These data show that maternal hypertension poses a significant risk for polycythemia, regardless of fetal growth. We suggest that, to prevent possible sequela, hematocrit is measured routinely in all infants of hypertensive mothers for prompt diagnosis and treatment.
Chi-Square Distribution↗
Studies of the mechanism of polycythemia induced in rats by Ni3S2.
Intrarenal injection of 10 mg Ni3S2 elicits polycythemia in rats. This can be attributed either to direct stimulation or to erythropoietin-induced hyperplasia of erythropoietic elements of bone marrow. While studying the mechanism of this experimental model of polycythemia we noted that: (a) extirpation of the injected kidney after the development of the hematologic alterations abolished the polycythemia within 1 month; (b) intravenous, intramuscular or intrahepatic treatment with Ni3S2 was ineffective in producing polycythemia; and (c) there was a modest but statistically significant elevation of plasma erythropoietin levels in rats 2,4 and 8 weeks after injection of Ni3S2, at a time when the hematocrit values were increased. The experiments support the view that Ni3S2 does not directly stimulate erythropoiesis in bone marrow but primarily affects the injected kidney, which in turn (by the continuous liberation of modest amounts of erythropoietin or some hitherto unknown substance) triggers the development of polycythemia.
Animals↗
Microcytic polycythemia. Frequency of nonthalassemic causes.
A high RBC count combined with a low mean volume generally is attributed to thalassemia minor, either alpha or beta, or to polycythemia vera with iron deficiency. Among 330 patients with a mean corpuscular volume (MCV) less than 70 cumu, 35 had increased RBC counts. Of these, 26 had thalassemia minor and four had polycythemia vera. Five had secondary polycythemia (four from hypoxia, one from hypernephroma) with incidental iron deficiency. In the four of these patients given iron, the RBC count remained above normal and the MCV rose to normal. The RBC size distribution curves reliably distinguished between thalassemia minor and polycythemia with iron deficiency.
Anemia, Hypochromic↗
Endogenous erythroid colony formation by peripheral blood mononuclear cells from patients with myelofibrosis and polycythemia vera.
Peripheral blood mononuclear cells from patients with polycythemia vera or myelofibrosis with myeloid metaplasia were studied for their erythroid colony growth characteristics in plasma clot cultures. In both diseases, erythroid colonies formed early in culture in the absence of added erythropoietin (endogenous colonies). In no instance did early, endogenous colony formation occur with peripheral blood cells from normals or patients with secondary polycythemia. A normal response to erythropoietin was observed with both control and patients' peripheral blood cells. Spleen mononuclear cells obtained from one patient with myelofibrosis also produced endogenous colonies and showed a response to erythropoietin. This study suggests that culture of peripheral blood mononuclear cells might serve as a useful tool in discriminating polycythemia vera from secondary polycythemia.
Cells, Cultured↗
[New criteria for differential diagnosis of polycythemia vera and erythrocytosis].
"Laborskel-analyzer" (PSL-1) was used to estimate red blood cell volume for the differential diagnosis in 36 polycythemia vera, 20 erythrocytosis patients and 30 normal subjects. Erythrocyte count of polycythemia vera patients (I, IIA and IIB stages) showed a shift to the left (an increase of microcytic fractions), while erythrocyte count++ of 20 erythrocytosis patients (16 of them with a relative erythrocytosis and 4 with an absolute erythrocytosis) were close to erythrocyte count++ of normal subjects. The counting of the percent content of erythrocytic fractions of varying volumes has proved fraction 5 with the erythrocytic volume from 56 microns 3 to 62 microns 3 to have the highest information content. The percent content of this fraction in polycythemia vera fluctuated from 3.9 to 19.5%, and in erythrocytosis it was from 0.9 to 3.0%, that could serve as a criterion for the differential diagnosis of polycythemia vera and erythrocytosis.
Adult↗
Isolated cerebellar infarction as a presenting symptom of polycythemia vera.
Although polycythemia vera is one of the reported causes for cerebral infarction, isolated cerebellar infarction, a rare disorder, was never reported in combination with polycythemia vera. This is a report of a 72-year-old woman in whom isolated cerebellar infarction was the presenting manifestation of polycythemia vera. The patient was treated with recurrent phlebotomies until the hematocrit decreased to < 45%. This treatment was followed by marked neurological improvement. A better awareness of the possibility of cerebellar infarction in polycythemia vera may disclose additional cases.
Aged↗
Polycythemia vera. The in vitro response of normal and abnormal stem cell lines to erythropoietin.
Bone marrow cells from two glucose-6-phosphate dehydrogenase (G-6-PD) heterozygotes with polycythemia vera were cultured to determine whether progenitors which wre not of the polycythemia vera clone were present, and, if present, which cell lines contributed to the increase in erythroid colonies observed in response to added erythropoietin (ESF). To accomplish this, the G-6-PD isoenzyme activity of individual erythroid colonies was determined. All of the erythroid colonies analyzed in cultures without added ESF, contained the G-6-PD isoenzyme type characteristic of the abnormal clone. With higher ESF concentrations in the culture, however, there was an increase in the colonies that were not of the polycythemia vera clone. Analysis of the ratio of the various types of colonies indicated that normal and polycythemia vera cells are capable of responding to ESF in vitro. In selected patients, this technique permits analysis of the ratios of normal to abnormal cells during the course of the disease, in response to therapy and during late complications, such as myelofibrosis or leukemic transformation.
Clone Cells↗
Polycythemia rubra vera progressing to Ph1-positive chronic myelogenous leukemia.
Polycythemia rubra vera and chronic myelogenous leukemia are both myeloproliferative disorders and, as such, share certain clinical features. Although some myeloproliferative disorders may transform into others, conversion of polycythemia rubra vera to chronic myelogenous leukemia has been denied. We report here an elderly man with polycythemia rubra vera and a normal leukocyte alkaline phosphatase who developed chronic myelogenous leukemia with a low leukocyte alkaline phosphatase and a marrow karyotype of 45, X, Ph1-positive. In addition, we have collected evidence of two similar cases and thus conclude that, although uncommon, polycythemia rubra vera may on occasion progress to chronic myelogenous leukemia.
Adult↗
[Hemoglobin J Amiens beta 17 (A 14) Lys replaced by Asn. Coincidence of a functionally silent new abnormal hemoglobin and a polycythemia vera (author's transl)].
A new abnormal hemoglobin, Hb J Amiens beta 17 (A 14) Lys replaced by Asn, has been discovered during the exploration of a recent polycythemia in a 65-year-old patient of Spanish extraction. Oxygen affinity of washed red blood cells was found to be normal at pH 7.13 (P 50 = 30.0 mmHg, N = 29.5 +/- 1). Cooperativity is unchanged, and no instability was detected. From this study, it is concluded that there is no relation between this functionally silent hemoglobin and the polycythemia. In fact, the recent appearance of the polycythemia, the involvement of the other blood cell lines, particularly the thrombocytosis, the high score of leukocyte alkaline phosphatases, and the results of the bone marrow biopsy led to the diagnosis of polycythemia vera.
Aged↗
Prolonged remission of leukemia associated with polycythemia vera.
A patient with polycythemia vera (PV) received successive treatment by phlebotomies, radioactive phosphorus, myleran and cyclophosphamide. Sixteen years after the diagnosis, he developed acute myeloblastic leukemia. A complete remission was achieved following two courses of COAP (cyclophosphamide, vincristine, Cytosine Arabinoside, and prednisone) therapy. Four months later, while still in leukemic remission, he became mildly polycythemic again and the treatment with phlebotomies and cyclophosphamide was resume. The patient has subsequently been in complete remission of leukemia for over three years and his polycythemia is controlled by small doses of cyclophosphamide. This appears to be a unique case of such a prolonged remission of leukemia in the course of PV, with a return to a mild polycythemia state.
Aged↗
32P-therapy in polycythemia vera.
A group of 52 consecutive patients with polycythemia vera was submitted to long-term therapy with radioactive phosphorus (32P). Initial phase of therapy induced complete remissions (normalization of hematogram; spleen not palpable) in 45% of the patients, and partial remissions in the remaining 55%. During maintenance therapy of the complete remission group, mean remission time was about 3.5 years. Individual remission times ranged between 1 and 6 years. In the group of patients with incomplete remission, mean remission time increased with the progression of the disease due to gradual development of "spent" -polycythemia. In patients with splenomegaly, remission time was negatively correlated to spleen size. In both groups the increment of annual accumulated dose averaged 2.4 mCi 32P. When considering polycythemia related causes of death only, mean survival time attained 12 years after initial treatment with 32P. Acute leukemia occurred in 2 patients (4%).
Adult↗
Polycythemia vera: stem-cell and probable clonal origin of the disease.
Two women with polycythemia vera and heterozygosity (GdB/GdA) at the X-chromosome-linked locus for glucose-6-phosphate dehydrogenase were studied to determine the nature of the cellular origin of their polycythemia. In contrast to unaffected tissue, such as skin fibroblasts, which consisted of both B and A types, the glucose-6-phosphate dehydrogenase of the patients' erythrocytes, granulocytes and platelets was only of Type A. These results provide direct evidence for the stem-cell nature of polycythemia vera and strongly imply a clonal origin for this disease. The fact that no descendants of the presumed normal stem cells were found in circulation suggests that bone-marrow proliferation in this disorder is influenced by local (intramarrow) regulatory factors.
Blood Platelets↗
Polycythemia produced in rats by environmental contaminants.
Polycythemia developed in progeny from mothers who were exposed during pregnancy to a combination of methylmercury chloride plus ethylurea and sodium nitrite. The polycythemia occurred as early as one month of age and as many as 24% of the offspring developed the polycythemic condition. Many features of this condition are similar to those of polycythemia vera in man, such as elevated hematocrits and white and red blood cell counts, splenomegaly, and hyperplasia of bone marrow accompanied by megakaryocytosis.
Animals↗