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Biomedical subjects

E Kelemen

Publications and source records attributed to E Kelemen.

At least 19 recordsLinked to original sources
PubMed2000

Immunological importance of chimerism in transplantation: new conditioning protocol in BMT and the development of chimeric state.

Chimerism is an exceptional immunogenetic state, characterized by the survival and collaboration of cell populations originated from two different individuals. The prerequisits to induce chimerism are immuno-suppression, myeloablation, or severe immunodeficiency of the recipients on the one side and donor originated immuno-hematopoietic cells in the graft on the other. The pathologic or special immunogenetic conditions to establish chimerism are combined with bone marrow transplantation, transfusion, and various kinds of solid organ grafting. Different types of chimerism are known including complete, mixed and mosaic, or split chimerism. There are various methods used to detect the type of chimera state, depending on the immunogenetic differences between the donor and recipient. The induction of complete or mixed chimerism is first determinated by the effect of myeloablative therapy. The chimera state seems to be one of the leading factors to influence the course of the post-transplant period, the frequency and severity of GVHD, and the rate of relapse. However, the most important contribution of the chimeric state is in development of graft versus leukemia effect. A new conditioning protocol (DBM/Ara-C/Cy) for allogeneic BMT in CML patients and its consequence on chimera state and GVL effect is demonstrated.

Antineoplastic Agents, Alkylating↗
PubMed1999

Responses to single-dose thrombopoietin decrease with higher platelet counts in mice.

Since the description of human thrombopoietin (TPO) we investigated the thrombocytosis-inducing capacity of human serum samples derived from individuals with altered thrombocytopoiesis. Several times the degree of thrombocytosis developing in recipient mice differed markedly even when applying the same human material. In the last 2 years, we applied single doses of recombinant human TPO (rHuTPO) to random-bred CFLP mice, and the same observation was made. Taken together with previous information (before 1970) it was possible to select cases in which the percent increases in circulating platelet counts inversely correlated with the starting levels. It appears, however, that apart from the known absorbing role of platelets and megakaryocytes, the response to single doses of exogenous rHuTPO in mice depends, at least partially, on an unknown endogenous homeostatic mechanism. Mixing thrombopoietically active human sera with platelet-free normal serum in a 1:1 ratio remarkably reduced the thrombocytosis-inducing capacity. Repeated pharmacological doses of TPO, applied in the majority of the reported trials, however, easily obscure the physiological control mechanism.

Animals↗
PubMed1998

[A new radiation-free conditioning in bone marrow transplantation and dibromo-mannitol therapy in chronic myeloid leukemia].

A new, radiation-free, conditioning protocol, containing the original Hungarian mitobronitol (DBM) (DBM/ cytosine arabinoside/cyclosphosphamide) has been applied to 36 chronic myeloid leukemia (CML) patients followed by bone marrow transplantation (BMT) from HLA identical sibling donors between 1990-1997. In spite of some prognostically disadvantageous factors (half of them were above 40 years, 10 out of 36 patients were in accelerated phase, the disease history was longer than 2 years in average) the overall survival (30/36) and the leukemia free survival rate (26/36) were in accordance with the best international results. Transplantation-related toxicity was remarkably reduced in comparison to bone marrow transplantation performed by total body irradiation/cyclophosphamide (TBI/Cy) or busulphan/cyclophosphamide (Bu/Cy) conditioning protocols. Acute graft versus host disease was present in lower percentage (9/36) and the number of serious cases was only 2/36. Chronic GVH disease, generally known to be associated with antileukemic effect (GVL), occurred in 25 of cases. Early haematological relapse among the 34 patients with functioning graft occurred in 6 patients which rate is slightly higher than reported after TBI/Cy or Bu/Cy conditioning treatment. There was no relapse among patients transplanted within one year post-diagnosis and patients having CML with accelerated phase. The leukemia free post-transplant period was in association with the chronic GVH disease and full chimeric state.

Adolescent↗
PubMed1998

Reduction in the frequency of transplant-related complications in patients with chronic myeloid leukemia undergoing BMT preconditioned with a new, non-myeloablative drug combination.

A radiation-free, non-myeloablative, myelosuppressive protocol, containing dibromomannitol and cytosine arabinoside, that remarkably reduced the frequency of transplant-related complications, such as veno-occlusive liver disease (VOLD), severe mucositis, bacterial sepsis, hemorrhagic cystitis, interstitial pneumonitis, has been applied in 19 CML patients, allotransplanted from identical siblings. Five patients were in accelerated phase. Acute GVHD developed in two patients and chronic GVHD occurred in 66% of patients. Follow-up was 3 to 7 1/2 years. Although only eight patients were under 30 years of age, and only two patients had a history of less than 1 year, the leukemia-free survival was 82%. There were four hematological relapses. The reduction in post-BMT complications has greatly enhanced quality of life. The nurses reported significant reduction of work-load. Savings in eliminating the need for irradiation, parenteral nutrition, and several antibiotics are also remarkable. The remarkable reduction of certain transplant-related complications shows some advantage against busulphan-preconditioning.

Adult↗
PubMed1998

Haemopoietic cell transplantation activity and results: a single institution experience.

Between February 1993 and November 1997, 62 patients with severe aplastic anaemia (SAA), acute myeloid (AML), acute lymphoid (ALL), or chronic myeloid leukaemia (CML) as well as two patients with NHL underwent allogeneic marrow transplantation (BMT) from HLA-identical or one-antigen mismatched sibling or unrelated donors. Patients received preparative regimens according to the baseline disease. Patients with SAA were conditioned with ATG/Cy (2 cases) and TAI/Cy (3 cases), AML, ALL and NHL with TBI/Cy (21 cases including two retransplantations) and CML with Mitobronitol/Ara-C/Cy except two patients conditioned traditionally with Bu/Cy. For GVHD prevention, patients received cyclosporin-A (CsA) with short course methotheraxe according to the Seattle protocol. Significantly better overall survival rates were associated with the Mitobronitol (DBM)/Ara-C/Cy conditioning regarded the patients as a whole. Autologous stem cell transplantation (bone marrow and/or peripheral blood) were performed in ten cases including 2 AML, 4 non-Hodgkin's lymphoma (NHL), 3 Hodgkin's disease (HD) and 1 patient with multiple myeloma (MM). Patients with AML and two patients with NHL were conditioned with TBI/Cy and the others with BEAM combined chemotherapy. Eight out of ten patients are leukaemia- or lymphoma-free survivors. One patient relapsed having conventional chemotherapy and interferon maintenance therapy. One patient died in a rapid relapse five months post-BMT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Comparison of the lymphoid toxicities of mitobronitol and busulphan in mice: reduced B cell toxicity and improved thymic recovery as possible contributors to the reduced risk for complications following BMT with mitobronitol preconditioning.

It has previously been reported that the use of mitobronitol (dibromomannitol, DBM) instead of busulphan (BU) for myelosuppression is associated with significantly decreased risk for several complications of allogeneic bone marrow transplantation in accelerated chronic granulocytic leukemia. In exploring the pharmacologic basis for this observation, we have compared the acute and subacute cytotoxicities of DBM and BU on the spleen and thymus of mice. While there was comparable early (day 3) weight loss in both organs following these treatments, splenic B cells exhibited significantly less damage, and thymic regeneration (over weeks) was significantly faster following DBM treatment than with BU. These observations raise the possibility that improved post-BMT immune recovery could contribute to the clinical benefits observed with DBM-preconditioning.

Animals↗
PubMed1997

Xenogeneic transfer of fetal liver and adult bone marrow-derived haemopoietic cells in rodents: changes in spleen colony differentials with increased doses of cells.

The effect of very high haemopoietic cell doses were investigated on the composition of splenic cell colonies/clusters in irradiated animals under xenogeneic circumstances. Differential cluster/colony counts from serial histological sections of the spleen were investigated before, and 9-12 days after transplantation of fetal liver- or adult bone marrow-derived haemopoietic cells following 5.0 to 8.5 Gy total body irradiation. Syngeneic as well as xenogeneic (mouse to rat and rat to mouse) transplantations were carried out. Cluster/colony differentials changed with the increase of the injected cell mass from 10(5) to 10(6) and 10(7) or more, i.e. the overwhelming erythroid pattern became trilinear even with xenogeneic transplants.

Animals↗
PubMed1996

[The bone-marrow transplantation program in Hungary: report from the period 1990-1995].

The article summarises the statistical data of bone marrow transplantation (BMT) carried out in Hungary between 1990-1995 in yearly distribution. Since the first BMT up to the end of 1995, 168 BMT were performed. The number of transplantations since 1990 to our days was gradually increasing. As a result of this activity in the three transplantation centers (National Institute of Haematology and Immunology, St. László Hospital and County Hospital in Miskolc) 36 allogeneic and 12 autologous BMT were performed in 1995. Out of the allogeneic BMT cases, 14% of them were completed with unrelated, donors in the last three years. The most frequent indications for allogenic BMT are: chronic myeloid leukaemia (CML), acute lymphoid leukaemia (ALL), acute myeloid leukaemia (AML), myelodysplasia, severe aplastic anaemia. Child allogenic BMTs are carried out on pediatric patients in St. László Hospital in leukaemia, severe aplastic anaemia cases and children born with immunodeficiency. Autologous BMTs started in an organised way in 1995 for adult patients in cases of non-Hodgkin lymphoma, Hodgkin lymphoma and for children with solid tumour indication in the Miskolc Centre. BMT activity in Hungary compared with international data, especially within Europe, shows a significant drop behind. To calculate for ten million inhabitants, the optimal BMT activity should be between 100-200 transplantations (allogeneic and autologous BMT together) in 1994. Among the Central European countries Hungary and Poland fall most behind. Autologous BMTs in most countries of Europe are above of allogeneic BMTs in numbers as indication in cases of lymphoma and solid tumours (first of all mamma carcinoma) comes into focus. This summary emphasises the most important difficulties in connection with the development of the National BMT program.

Adolescent↗
PubMed1995

Consecutive appearance of coagulation factor XIII subunit A in macrophages, megakaryocytes, and liver cells during early human development.

Thirty embryonic and fetal samples were investigated to study the appearance and characteristics of factor XIII subunit A (FXIIIA)-containing cells in the course of human development. Samples were either vacuum-embedded in paraffin for staining FXIIIA by a sensitive biotin-streptavidin system or snap-frozen for double-labeling studies to characterize FXIIIA-containing cells. FXIIIA appeared as early as the fifth gestational week in yolk sac samples in stellate-shaped cells. Nonparenchymal cells in liver samples showed intense labeling for FXIIIA from the sixth week of gestation. The relative amount of FXIIIA-containing cells rapidly diminished up to the 13th gestational week. When characterized, the majority of these cells proved to be KiM7-positive macrophages, while GPIb (CD42b)-labeled cells accounted for less than 10% of FXIIIA-positive cells. Liver cells did not show any staining for FXIIIA in first trimester samples. The earliest liver specimen showing FXIIIA was at the 20th week, when FXIIIA appeared in some liver cells, particularly in those surrounding the central veins. In bone marrow smears, FXIIIA-positive cells started to appear at week 10 in the clavicles and increased in number in subsequent stages of development. Intracellular FXIIIA was distributed between GPIb-, RFD7-, and KiM7-positive cells. The results indicate that, apart from liver cells, at least three different cell populations (KiM7+ RFD7+ GPIb-, KiM7- RFD7- GPIb-, and KiM7- RFD7- GPIb+) contain FXIIIA in the early phase of human development. We conclude that FXIIIA appears very early during human development and is detectable in both extra- and intraembryonic hematopoietic organs. Intracellular FXIIIA in early human development is distributed between different macrophages and megakaryocytes, and by week 20, it appears in liver cells as well.

Antigens, Differentiation↗
PubMed1995

[Survey of one hundred patients with chronic granulocytic leukemia from the view of recent developments].

Data of 100 selected CGL patients were considered. There were 50 male and 50 female patients with an average 38.1 and 41.5 years of age, respectively. Seventy nine patients were in stable, chronic and 21 patients were in accelerated phase. Patients first admitted in blastic phase were excluded. Twenty two patients were subjected to bone marrow transplantation. Characteristically low levels of neutrophil alkaline phosphatase were absent in about 10 to 25% of early cases. It was considered that the level of positive cells could eventually point to the extent of normal population. In the group of the accelerated patients the neutrophil alkaline phosphatase scores were regularly high and the serum cholesterol values lower than those among stable-phase patients. The role of G-CSF (granulocyte colony stimulating factor) was considered. Secondary myelofibrosis was frequently associated with low serum cholesterol. Average survival time was 41 month among non-transplanted and 63+ months among identically-transplanted patients. In accordance with the literature, authors point out that in the presence of any factor not permitting transplantation, prolonged high-dose interferon-therapy could be the first choice, because unlike chemotherapeutic agents used till now, it prolongs survival. Apart from this autotransplantation with marrow or with circulating blood derived stem cells should be considered.

Adolescent↗
PubMed1994

Onset and distribution of factor XIII-containing cells in the mesenchyme of chorionic villi during early phase of human placentation.

To learn more about the distribution and possible function of factor XIII (FXIII)-containing cells of human placenta, paraffin embedded and frozen sections of placenta samples from the first trimester of pregnancies--terminated by legal abortions--were studied by single and double labelling immunomorphological techniques. It was observed that at the fifth gestational week in the chorionic mesenchyme, FXIII-containing small mononuclear, round shaped cells start to appear. The relative amount of the FXIII-containing cells rapidly increased up to the seventh gestational week, reaching nearly 30 per cent of all mesenchymal cells. Simultaneously these cells differentiated into large stellate cells having numerous vacuoles in their cytoplasm. These cells were characterized in double labelling experiments and proved to be macrophages (CD 14+, KiM7+, labelled with antimacrophage monoclonal antibody). In the fifth-seventh weeks of gestation, these cells were homogenously scattered in the immature mesenchymal connective tissue, but from the eight gestational week they tended to accumulate in the peripheral part of chorionic villi while the central mesenchyme showed intense fibrotic changes. The abundance and characteristic distribution of the FXIII-positive macrophages in the chorionic mesenchyme during the first trimester of pregnancy suggest that these cells may have an active role in the formation of connective tissue in the early phase of placentation.

Chorionic Villi↗
PubMed1993

Graft-versus-host disease in bone marrow transplantation: experimental, laboratory, and clinical contributions of the last few years.

Graft-versus-host disease (GVHD) is a major and often lethal complication of bone marrow transplantation. Research of the past few years has greatly expanded our understanding of the disease and enriched the arsenal of preventive and therapeutic procedures. The present review attempts to give a survey of experimental and clinical GVHD, updating essential knowledge with the latest information until July 1993. The covered topics include the complex immune pathomechanism of acute and chronic GVHD in murine models, the pathogenic role of major, minor, and other antigenic disparities, laboratory markers predicting GVHD, factors influencing appearance and course of the disease, the relationship between GVHD and the graft-versus-leukemia effect, and novel experimental and clinically tested preventive and therapeutic modalities. Finally, the authors set forth their perspective on the most relevant questions in GVHD-related research.

Animals↗
PubMed1993

Non-supralethal mitobronitol/cytarabine/cyclophosphamide conditioning without irradiation before bone marrow transplantation for accelerated chronic granulocytic leukemia: apparent absence of acute graft-versus-host disease.

Cytostatic chemotherapy instead of supralethal total body irradiation (TBI) has been increasingly used as an alternative myeloablative regimen before bone marrow transplantation (BMT). While irreversible azoospermia/amenorrhoea seems to occur less frequently with such conditioning, graft-versus-host disease (GVHD) remains unaffected. Five-year disease-free survival in accelerated chronic granulocytic leukemia (CGL), after BMT with matched sibling grafts has been 0.10-0.30. Mitobronitol, cytosine arabinoside, and cyclophosphamide were used for conditioning. Patients were transplanted with unmanipulated HLA/MLC identical sibling bone marrow. For recovery, a pathogen-low room was available without air filtering and laminar airflow. Seven of eight accelerated-CGL patients were engrafted: full allogeneic reconstitution was detected in four and mixed chimerism in three patients. Five out of the seven engrafted patients survived at least nine months (median = 42 months), two are considered cured (8-9 years survival). The four leukemia-free survivors displayed full allogeneic reconstitution and presented symptoms of chronic GVHD. One patient became a genetically verified father. Acute GVHD and veno-occlusive liver disease (VOLD) were absent in all patients, diffuse interstitial pneumonitis (IP) occurred in one case. Non-supralethal conditioning with mitobronitol/cytarabine/cyclophosphamide in accelerated-CGL allows allogeneic bone marrow reconstitution with survival and cure rates comparable to those achieved with other protocols using TBI or busulphan conditioning. Unlike the latter treatments, however, our protocol leads to fewer transplant-related complications including acute GVHD, IP, VOLD, and azoospermia/amenorrhoea.

Adult↗
PubMed1992

Pregnancy in idiopathic aplastic anemia (report of 10 patients).

This paper reports on 6 patients with severe, 2 with moderate and 2 with mild aplastic anemia who had a total of 18 pregnancies after the diagnosis. All four pregnancies that occurred during the active state of severe and moderate aplastic anemias were electively terminated. Two out of 14 pregnancies that occurred during the long-term remission were electively terminated for non-medical reason, two spontaneous abortions occurred and 10 live births were seen. All offspring were healthy at follow-up. During pregnancy the circulating blood cell levels decreased in 1 out of 6 pregnancies in patients who were in remission from mild and moderate aplastic anemias, and in 4 out of 8 pregnancies in patients who were in remission from severe aplastic anemia. In all 5 cases that showed a relapse during pregnancy the remission recurred following the termination of pregnancy. The data presented suggest that aplastic anemia in long-term remission can unpredictably relapse during pregnancy, but its final outcome appears not to be affected by pregnancy. Furthermore, there is no correlation between the pre-pregnancy clinical course and the events during pregnancy. The outcome of pregnancy during the remission of aplastic anemia seems beneficial, and spontaneous delivery should be preferred.

Abortion, Therapeutic↗