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E Juvonen

Publications and source records attributed to E Juvonen.

At least 55 records · Page 3Linked to original sources
PubMed1993

Familial erythrocytosis genetically linked to erythropoietin receptor gene.

Familial erythrocytosis is heterogeneous with diverse causes. Using a highly informative, simple sequence repeat polymorphism in the 5' region of the erythropoietin receptor gene (EPOR), we did linkage analysis in a large family whose clinical and genealogical features were known. There were no recombinations between the disease phenotype and the polymorphism, the logarithm of odds score for linkage at zero recombination being 6.37. This highly significant linkage indicates that a mutation in EPOR is most probably responsible for the disease phenotype in this family.

Base Sequence↗
PubMed1993

Megakaryocyte and erythroid colony formation in essential thrombocythaemia and reactive thrombocytosis: diagnostic value and correlation to complications.

Megakaryocyte and erythroid colony formation in vitro by progenitors from the bone marrow and/or blood was studied in 61 patients with essential thrombocythaemia (ET) and 22 patients with reactive thrombocytosis (RT) using the methyl cellulose assay. 47 (77%) of the patients with ET showed megakaryocyte and/or erythroid spontaneous colony formation while 14 (23%) patients did not have any kind of spontaneous colonies. Spontaneous megakaryocyte colony formation was seen in 42 (69%) of the patients and 36 (59%) ET patients showed spontaneous erythroid growth. 31 patients had both types of spontaneous colonies. 11 patients showed only spontaneous megakaryocyte colony formation, and five patients only spontaneous erythroid growth. None of the patients with RT or of the normal controls showed either type of spontaneous growth. Neither the presence of spontaneous megakaryocyte colony formation nor the number of spontaneous colonies correlated with the platelet count. Patients with spontaneous megakaryocyte growth had significantly more often thromboembolic or haemorrhagic problems than those without spontaneous colony formation. In conclusion, it was found that a great majority of patients with ET but none of those with RT grow spontaneous megakaryocyte and/or erythroid colonies. Spontaneous colony formation is strong evidence for a myeloproliferative disorder. The presence of spontaneous colony growth is associated with an increased risk of thromboembolic or haemorrhagic complications regardless of the platelet count, particularly among young patients.

Adult↗
PubMed1993

Prolonged pure granulocytopenia in children.

In a prospective, population-based study, 31 patients with pure granulocytopenia lasting longer than six months were follow-up for up to 7.3 years after diagnosis. Their ages at diagnosis were 0.3-15.5 (median 0.9) years; 17 of the patients were less than 1 year of age. The lowest granulocyte count measured was 0.00-0.60 (median 0.03) x 10(9)/l. During the granulocytopenia, 12 patients suffered from repeated infections but none was life-threatening. In 21 patients, the granulocyte count normalized spontaneously within 0.5-5.5 (median 1.1) years: the other 10 remain granulocytopenic after follow-up for 2.5-7.3 (median 3.7) years. We conclude that selective granulocytopenia, if associated with unimpaired myelopoiesis, is a benign disorder in children and does not, even if prolonged, significantly increase the risk of severe infections.

Adolescent↗
PubMed1992

Recombinant human granulocyte-macrophage colony-stimulating factor in children with chemotherapy-induced neutropenia.

Twenty children 1-17 (median, 5.5) years of age received GM-CSF during chemotherapy-induced neutropenia at the dose of 5 micrograms/kg/day, continued until the absolute neutrophil count (ANC) exceeded 500 x 10(6)/liter. Twelve children with solid tumors received GM-CSF after courses of conventional chemotherapy (VP-16 + ifosfamide or "6 in 1"). One course followed by GM-CSF was compared to identical courses without GM-CSF in the same patients. Eight children with recurrent/poor risk malignancies received GM-CSF after marrow-ablative therapy and autologous bone marrow transplantation (ABMT). Their engraftment data were compared to matched historical controls. In both groups GM-CSF accelerated myeloid recovery, which was preceded by the appearance of immature myeloid elements in bone marrow. The ANC levels of 200, 500, and 1,000 x 10(6)/liter were exceeded 2, 3 (P < 0.05), and 6 (P < 0.005) days earlier with GM-CSF in the conventional chemotherapy group, and 6, 10 (P < 0.05), and 9 days earlier in the ABMT group, as compared to the controls. All adverse effects observed were mild, including skin rashes, nasal stuffiness, general achiness, nausea, and fever. We conclude that GM-CSF is well tolerated in children and accelerates myeloid recovery in chemotherapy-induced neutropenia.

Adolescent↗
PubMed1992

Bone marrow fractionation by the haemonetics system: reduction of red cell mass before marrow freezing, with special reference to pediatric marrow volumes.

For purposes of freezing autologous marrow or transplants of allogeneic marrow with major ABO blood group incompatibility, 54 freshly harvested bone marrows from children of 7-65 kg of weight were depleted of their red cells with the Haemonetics V50 system. The marrow volumes ranged from 230 to 1,145 ml, with 17 small (200-399 ml), 18 intermediate (400-799 ml) and 19 large (800-1,200 ml) volumes. After processing, the median recoveries were: volume 24%, red cell mass 18%, and nucleated cells 75%. In the small marrow volume group, a good nucleated cell recovery was achieved at the expense of red cell depletion. The colony-forming units, granulocytes-macrophages (CFU-GM) were normal after thawing of processed, cryopreserved marrows, and good engraftment of both allogeneic and autologous marrows were achieved. We conclude that marrow processing with the Haemonetics V50 system results in adequate red cell depletion and good nucleated cell recovery without open-air contact of marrow or excessive time consumption. For small marrow volumes, however, the red cell depletion was suboptimal, and a bowl size smaller than 125 ml is desirable for pediatric use.

Adolescent↗
PubMed1991

Autosomal dominant erythrocytosis caused by increased sensitivity to erythropoietin.

We describe here a family with autosomal dominant erythrocytosis. In in vitro cultures, performed using the methyl cellulose assay, the number of erythroid colonies was normal or marginally increased when a standard concentration of erythropoietin (Epo) was used, but at lower Epo concentrations, the investigated persons formed more colonies than the controls. The difference was generally greater the lower the Epo concentration became. Some erythroid colony growth was seen even in the absence of any added Epo (apart from the minute concentration found in fetal calf serum), a phenomenon not seen in the controls. This finding indicates that the erythrocytosis in this family is caused by hypersensitivity of erythroid progenitors to Epo. The serum Epo concentration was low or low normal in all of the investigated family members, which is in good accordance with hypersensitivity to Epo. The erythrocytosis has not had any obvious effect on the health or life-span of the affected individuals. Many of them have reached an advanced age, and one of the affected family members has won several Olympic gold medals and world championships in endurance sports.

Erythropoiesis↗
PubMed1990

Effect of culture conditions on in vitro erythroid colony formation in myelodysplastic syndromes.

In vitro colony formation by erythroid progenitors from the bone marrow was studied in 42 patients with a myelodysplastic syndrome using both a standard assay for growing erythroid colonies and an assay designed for growing megakaryocyte colonies. In the standard assay 5 patients had normal numbers of erythroid burst-forming unit (BFU-E) colonies, 8 showed reduced numbers of colonies, and 29 patients had no colony formation. Six patients with markedly reduced numbers of erythroid colonies or no colonies at all in the standard assay showed normal or increased numbers of erythroid colonies in the megakaryocyte assay. In three of these patients the erythroid colony morphology was normal, whereas the other three showed abundant diffuse growth of erythroid subclusters with no normal colonies. In the other patients, the erythroid culture results were similar in both assays. These results indicate that the impairment of erythroid colony growth seen in most patients with a myelodysplastic syndrome is, at least in a number of patients, not due to reduced numbers of erythroid progenitors but to unusual milieu requirements of abnormal progenitors.

Bone Marrow↗
PubMed1989

Effect of haem arginate on colony formation by haematopoietic progenitors in vitro.

The effect of haem arginate, a new stable haem compound, was studied on colony formation by erythroid (CFU-E, BFU-E) and granulocyte-macrophage (CFU-GM) progenitors from the bone marrow of 12 healthy persons. At the concentration of 10 mumol/l haem arginate significantly (p less than 0.05) increased and at the concentration of 200 mumol/l significantly decreased (p less than 0.005) the colony formation of CFU-E. A similar, though not significant, trend was seen in the BFU-E colony growth, while the CFU-GM colony formation was not influenced at any concentration between 1 and 200 mumol/l. We conclude that the stimulation of erythropoiesis in vitro is seen at lower concentrations with haem arginate than with former haemin preparations.

Arginine↗
PubMed1989

Spontaneous erythroid colony formation in the differential diagnosis of erythrocytosis.

Erythroid colony formation in vitro was studied in 80 patients with erythrocytosis. 43 of the patients had polycythaemia vera (PV), 18 patients had secondary erythrocytosis, 6 had normal red cell mass, and 13 patients were regarded as unclassified. Spontaneous erythroid colony formation, in the absence of exogenous erythropoietin in the cultures, was discovered in all patients with PV, whereas no patient with secondary erythrocytosis or with normal red cell mass showed this phenomenon. 8 of the 13 patients with unclassified erythrocytosis spontaneously formed erythroid colonies. 7 patient with unclassified erythrocytosis have been followed for 5 yr. 3 of the 4 patients with spontaneous colony growth but none of the 3 without it can now be classified as PV. Thus, spontaneous erythroid colony formation indicates PV even in early and atypical cases. Therefore, the culture of erythroid progenitors is very useful in the differential diagnosis of problematic cases with erythrocytosis.

Adult↗
PubMed1989

Colony formation by megakaryocyte progenitors in myelodysplatic syndromes.

In vitro megakaryocytic colony formation by progenitors from the bone marrow was studied in 40 myelodysplastic syndrome patients. Megakaryocytic colonies were decreased in number or absent in 30 patients; only 10 showed normal colony growth. The growth correlated to some extent with the FAB-class. Patients with normal colony formation had either RA or RARS, but also in these two FAB-types half of the patients showed reduced megakaryocytic colony formation. Only 1 out of 15 patients with RAEB or RAEBt had normal megakaryocyte growth. The patients with CMML did not show any megakaryocytic colonies. The growth of erythroid colonies was normal in 3 patients and reduced or absent in the others. All 3 with normal erythroid colony formation also showed normal megakaryocyte growth, and all patients with normal megakaryocyte colony formation also had normal granulocyte-macrophage colony growth. Granulocyte-macrophage colony and cluster formation was normal in 17 patients. Defective formation of megakaryocytic, erythroid, and granulocyte-macrophage colonies was seen in 22 patients, compatible with a defect in a pluripotent stem cell. Megakaryocytic colony formation had no obvious correlation with any specific chromosome abnormality, and the distribution of the growth patterns was almost similar in patients with a normal and those with an abnormal karyotype.

Adult↗
PubMed1988

Megakaryocyte colony formation in chronic myeloid leukemia and myelofibrosis.

Colony formation by megakaryocytic progenitors from the blood or bone marrow was studied in 22 patients with chronic myeloid leukemia (CML) and in 17 patients with idiopathic myelofibrosis (MF). Thirteen of the 22 CML patients showed megakaryocytic colony formation, when PHA-LCM and plasma of a patient with aplastic anemia were used as a source of colony stimulating activity. Twelve of these 13 patients also showed spontaneous megakaryocytic growth, i.e. colony formation when PHA-LCM was omitted and normal plasma was used instead of aplastic plasma. All the untreated CML patients exhibited both stimulated and spontaneous growth. Each patient without any megakaryocytic colony formation had recently received cytotoxic treatment. Thirteen of the 17 patients with MF grew megakaryocytic colonies and ten of these 13 patients also showed spontaneous megakaryocytic growth. The colony numbers were roughly similar in the stimulated and non-stimulated cultures. The present study shows that spontaneous megakaryocytic colony formation, previously shown to be common in PV and ET, is also seen in many patients with CML and MF.

Adult↗
PubMed1988

Megakaryocytic colony formation in polycythaemia vera and secondary erythrocytosis.

Megakaryocytic colony formation by progenitor cells of 18 patients with polycythaemia vera, seven with secondary erythrocytosis and four with erythrocytosis of unexplained origin was studied in vitro by the methyl cellulose culture assay. Fourteen of the 18 patients with polycythaemia vera showed spontaneous megakaryocytic colony formation, i.e. colony growth with normal human plasma as the only source of colony stimulation. None of the patients with secondary erythrocytosis or erythrocytosis of unknown origin or of the normal controls grew colonies in the presence of normal human plasma only. When the plasma of a patient with aplastic anaemia was used instead of normal human plasma and phytohaemagglutinin stimulated leucocyte conditioned medium (PHA-LCM) was added to the culture medium, two of the patients with polycythaemia vera and one with secondary erythrocytosis formed slightly increased numbers of megakaryocytic colonies, while the rest of the patients showed normal colony formation. All of the patients with polycythaemia vera but none of those with secondary erythrocytosis or erythrocytosis of unknown origin showed spontaneous erythroid colony growth. The present study shows that most patients with polycythaemia vera form spontaneous megakaryocytic colonies in vitro. This phenomenon has recently also been demonstrated in essential thrombocythaemia and it is apparently analogous to spontaneous erythroid colony growth seen in all myeloproliferative disorders.

Adult↗
PubMed1988

Mechanism of anaemia in rheumatoid arthritis: demonstration of raised interleukin 1 beta concentrations in anaemic patients and of interleukin 1 mediated suppression of normal erythropoiesis and proliferation of human erythroleukaemia (HEL) cells in vitro.

The pathogenesis of the anaemia associated with rheumatoid disease is unclear. It has previously been shown that the degree of the anaemia correlates with the severity of the inflammatory disease and that serum from patients with arthritis inhibits erythropoiesis. This study was designed to examine whether interleukin 1 could be a mediator of the anaemia in rheumatoid arthritis. Radioimmunoassay of interleukin 1 beta in serum showed that patients with rheumatoid arthritis and associated anaemia had significantly higher interleukin 1 beta concentrations than patients with rheumatoid arthritis without anaemia. Pure recombinant human interleukin 1 alpha and interleukin 1 beta, in concentration ranges similar to those found in the arthritic patients, markedly suppressed the colony formation of the erythroid, but not the granulocyte-macrophage progenitor cells in cultures of normal bone marrow. Natural human interleukin 1 and recombinant interleukin 1 beta, but not interleukin 1 alpha, suppressed in a dose dependent manner the proliferation of the human erythroleukaemia cell line (HEL) in cultures, suggesting that the interleukin 1 effect is a direct one. The results show that interleukin 1 is a humoral inhibitor of erythropoiesis and suggests that interleukin 1 is involved in the development of anaemia in association with rheumatoid arthritis.

Adult↗
PubMed1988

Erythroid colony formation and effect of hemin in vitro in hereditary sideroblastic anemias.

Colony formation by erythroid burst-forming units (BFU-E) and erythroid colony-forming units (CFU-E) and the effect of hemin on colony growth was studied in vitro in three Finnish families with hereditary sideroblastic anemia (HSA). Defective activity of heme synthase has been demonstrated in family A and that of delta-aminolevulinic acid synthase in family B. No biochemical defect has been recognized so far in family C. CFU-E colony growth was defective in seven of the eight persons studied. The formation of BFU-E colonies was normal in family A and increased in family C, whereas of the two members of family B one showed normal and one decreased BFU-E colony growth. Hemin in 30-120 microM concentration increased significantly both BFU-E (p less than 0.01) and CFU-E (p less than 0.005) colony formation in family C. No effect was seen in family A, and in family B the only effect was normalization of the decreased BFU-E colony growth by the highest hemin concentration in one person. This study indicates that differences exist between families with HSA in erythroid colony formation and in response to hemin in vitro, but the low number of investigated members in each family does not permit a conclusive evaluation of the impact of the carrier versus patient status or of sex on the results.

Adult↗
PubMed1987

Colony formation by megakaryocytic progenitors in essential thrombocythaemia.

Colony formation by megakaryocytic progenitors (CFU-M) from the blood or bone marrow of 12 patients with essential thrombocythaemia was studied in vitro with the methyl cellulose assay. When the cultures were stimulated with plasma from a patient with aplastic anaemia and with phytohaemagglutinin stimulated conditioned medium (PHA-LCM), the patients showed a significant trend towards higher circulating CFU-M numbers when compared with the controls; three of the patients exceeded our normal range. In the bone marrow cultures there were no differences in the number or morphology of megakaryocytic colonies between the patients and the controls. When normal human plasma was the only source of colony stimulating activity, 11 out of 12 patients, but none of the controls, showed megakaryocytic colony formation. The same patients also had 'spontaneous' erythroid colony growth without the addition of exogenous erythropoietin into the cultures. Only one of the patients with essential thrombocythaemia (ET) had normal megakaryocytic and erythroid colony formation. The present study shows that, in most patients with ET 'spontaneous' CFU-M colony formation occurs in suboptimal culture conditions, a phenomenon obviously analogous to the spontaneous erythroid colony formation seen in the myeloproliferative disorders.

Adult↗
PubMed1986

Megakaryocyte colony formation by bone marrow progenitors in myelodysplastic syndromes.

Megakaryocytic colony formation by precursor cells from the bone marrow was investigated in 10 patients with a myelodysplastic syndrome. All but one exhibited abnormal colony formation: four showed no colony formation at all, while a decreased number of colonies was noticed in five. All of the patients showed defective colony formation by erythroid progenitors, but only four showed clearly abnormal granulocyte-macrophage colony formation. The defect in megakaryocytic progenitors seems to be more akin to the defects occurring in erythroid progenitors than to the defects seen in the granulocyte-macrophage lineage.

Aged↗
PubMed1986

Effect of splenectomy on circulating haematopoietic progenitors in myelofibrosis.

The effect of splenectomy on peripheral blood CFU-GM and BFU-E numbers was studied in a patient with myelofibrosis. The numbers of CFU-GM and BFU-E were twice as high in the splenic venous blood as in the peripheral blood. The number of CFU-GM in peripheral blood decreased to 20% and that of BFU-E to 7% of the presplenectomy level at 1 wk after the operation. The progenitor numbers recovered to reach the presplenectomy level within 4-6 w after splenectomy. This effect of splenectomy was different from that seen in 3 patients with Hodgkin's disease, in whom increased numbers of progenitors were observed after a small initial notch.

Aged↗