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W Heit

Publications and source records attributed to W Heit.

At least 37 records · Page 2Linked to original sources
PubMed1990

Role of insulin during cell cycle in a myeloid cell line.

The characteristics of insulin receptor binding and structure and its proliferative and metabolic action in a human leukemic cell line was investigated during the cell cycle. Exponentially growing cells were separated by counterflow centrifugation which fractionates cells primarily on the basis of size into subpopulations representing G0/G1, S, and G2 + M cells. This method avoids disturbance of the cellular metabolism. After separation the cells showed a viability of at least 92%, underwent further proliferation, and remained morphologically unchanged, which was shown by electron microscopy. The cells could be enriched to 70-90% purity for G0/G1 phase and 50-60% purity for S and G2 + M phase, respectively, which was shown by DNA flow-cytometry. Specific binding of insulin could be demonstrated in G0/G1, S, and G2 + M enriched cells. Insulin binding sites decreased from 20-25,000 per cell in G0/G1 to 1-2,000 in S and increased to 30-50,000 in G2 + M. The affinity of insulin binding remained nearly constant during the cell cycle. The specificity of the insulin receptor could also be demonstrated by covalent crosslinking of the receptor to radiolabeled ligand in all enriched cell fractions. Glucose transport was stimulated by insulin independently of cell cycle. An increase to 140% of control was observed at an insulin concentration of 10 ng/ml. In contrast, glycogen synthesis could only be stimulated by insulin in the G0/G1 phase. An increase to 140% of control was already reached at 0.25 ng/ml insulin. Insulin in concentrations of 1 and 10 ng/ml stimulated the transit to S-phase in cycling, but not in resting, cells. The growth promoting action of insulin could be investigated by consecutive DNA analysis of the separated cells which had been stimulated by insulin.

Cell Cycle↗
PubMed1989

Assessment of human allospecific IL-2-secreting helper T lymphocytes in limiting dilution cultures using restimulation and split well analysis.

A limiting dilution (LD) culture was established which allows the detection of allospecific interleukin-2 (IL-2)-secreting helper T lymphocyte precursors (HTL-p) among human peripheral blood mononuclear cells (PBMNC). HTL-p stimulated with allogeneic Epstein-Barr virus-transformed B lymphoblastoid cell lines (EBV-LCL) in the presence of exogenous recombinant IL-2 (r-IL-2) clonally developed into IL-2 secreting effector cells when restimulated against the original stimulating alloantigen. Split well cultures were performed prior to restimulation to assess the antigen specificity of the response. Frequencies of alloreactive IL-2-secreting HTL-p ranged from 1/100 to 1/800. Allospecificity of effector T cells was determined by a strong decline of frequencies obtained after restimulation against third-party antigens. In (clonal) segregation analyses the vast majority of IL-2-secreting progenies (80%) were specific for the original stimulating alloantigen. Allele specificity was disclosed by using class II MHC related third-party restimulator cells. By comparison with LD short-term cultures it became evident that exogenous r-IL-2 in the initial culture period was required to reveal optimal precursor frequencies of IL-2-producing T cells. Furthermore, successful antigenic restimulation was strictly confined to these culture conditions.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1989

Evaluation of remission state in chronic myeloid leukemia patients after bone marrow transplantation using cytogenetic and molecular genetic approaches.

The remission state of 13 Philadelphia positive chronic myeloid leukemia patients was studied after bone marrow transplantation (BMT) by cytogenetic and Southern blot analysis of the breakpoint cluster region (BCR) gene. Eight of 13 patients showed neither clinical nor genetic evidence of residual disease. In two patients hematological relapse was confirmed by cytogenetic and molecular analysis. Evidence for residual leukemic cells in otherwise complete remission was obtained genetically in three patients. One of the latter cases revealed BCR rearrangement despite negative cytogenetic findings, while in another patient cytogenetic relapse was observed without demonstrable rearrangement within the major BCR. Our results may indicate that cytogenetic and molecular genetic methods complement rather than replace each other for the detection of residual CML cells after BMT.

Adolescent↗
PubMed1988

[Bone marrow transplantation as therapy in chronic myeloid leukemia].

Between April 1982 and December 1986, HLA-identical bone marrow transplantations were performed on 25 patients with Philadelphia chromosome-positive chronic myelocytic leukaemia (CML), 18 in the chronic phase, 7 in acceleration or blast crisis. Twelve of the 18 patients (67%) in the chronic phase are still alive a median period of 570 days after transplantation, but only two of the seven (29%) in acceleration or blast crisis a median period of 227 days after transplantation (P less than 0.025). The duration of the chronic phase was of great importance for survival after transplantation: 86% of patients in the chronic phase for less than two years survived, but all patients in the chronic phase for over two years died (P less than 0.001). CML relapses occurred in one patient in a late chronic phase and in two in an advanced stage of the disease. These results confirm the unfavorable outcome of bone marrow transplantation in the accelerated phase or blast crisis, as well as in the late chronic phase. Since at present there are no reliable risk factors for the occurrence of acceleration or blast crisis, bone marrow transplantation should be undertaken as early as possible in the chronic phase of CML.

Adolescent↗
PubMed1988

Antimicrobial prophylaxis in neutropenic patients after bone marrow transplantation.

Fourty-one patients with haematological malignancies or severe aplastic anaemia underwent allogeneic or syngeneic bone marrow transplantation and received one of two forms of infection prophylaxis while granulocytopenic: total decontamination in strict reverse isolation (ITD, 26 patients) or selective decontamination of the digestive tract with barrier nursing (SD, 15 patients). The patients were evaluated for infection acquisition, fever days, days on systemic antibiotics and granulocyte transfusions from 48 hours after the beginning of the decontamination procedure until 1,000 granulocytes/microliter have been reached. Ten of 26 patients of the ITD group remained free of febrile episodes and infections, whereas all patients of the SD group acquired infections (p less than 0.001). During granulocytopenia patients of the ITD group had fewer fever days, were less frequently on systemic antibiotics and received fewer granulocyte transfusions as compared with the SD group. Both methods were obviously very effective in preventing gram-negative infections, infections caused by Staphylococcus aureus and infections due to yeasts or fungi. No death due to infection occurred in either group. However, the data of this study provide evidence that ITD is a more effective antimicrobial prophylaxis in bone marrow transplant recipients than SD.

Adolescent↗
PubMed1988

[Pulmonary complications following bone marrow transplantation as seen on the x-ray].

In a retrospective study chest radiographs of 87 bone marrow transplant recipients were analysed. 36 patients had pulmonary complications with lung opacifications. Interstitial changes were more frequent than airspace pneumonias. The latter were caused by bacteria and fungi only. The most common cause of pulmonary complications was cytomegalovirus pneumonia. It was characterised uniformly by a bilateral diffuse interstitial pattern. Idiopathic interstitial pneumonias were indistinguishable from CMV infection. Pneumonias caused by Epstein-Barr virus and protozoa, diffuse radiation pneumonitis and leukaemic infiltrates were rare and also associated with interstitial changes.

Adolescent↗
PubMed1988

Induction of myeloperoxidase in five cases of acute unclassified leukaemia.

For further analysis of their lineage affinity the differentiation capacity of five cases of acute unclassified leukaemias were studied in vitro using 5 nM 12-O-tetradecanoyl-phorbol-13-acetate as an inducing agent. After 4 d in vitro a co-expression of both myeloid and early B-lymphoid or myeloid and early T-lymphoid antigens on the same population of cells was found. While ultrastructural analysis of the blasts prior to culture revealed the morphology of undifferentiated blasts without any specific endogenous peroxidase activity, the cultured blasts displayed monoblastic features and myeloperoxidase activity after 4 d in vitro. Since this type of peroxidase is highly specific for the myelomonocytic lineage the data indicate myelomonocytoid differentiation of all five cases studied. The co-expression of lymphoid as well as myeloid antigens and myeloperoxidase by the same blasts after culture could be indicative of bilineage differentiation capacity characterizing the original blasts as bipotential progenitor cells.

Acute Disease↗
PubMed1988

T-cell depletion versus methotrexate as GvHD-prophylaxis in allogeneic bone marrow transplantation for leukaemia.

Graft-versus-host disease (GvHD) prophylaxis using methotrexate (23 patients) and T-cell depletion of the graft (40 patients) was compared in 63 allogeneic bone marrow transplantations (BMT) for leukaemia. T-cell depletion significantly reduced (p = 0.001) the incidence of GvHD from 68% to 11% and the GvHD-associated mortality from 79% to 5%. Actuarial disease-free survival for low-risk patients (57% with T-cell depletion and 47% with MTX) was not significantly improved, due to graft failure and possibly due to a higher leukaemic relapse rate after T-cell depletion. Prevention of graft failure after T cell-depleted BMT is essential and could also reduce the risk of leukaemic relapse by improved engraftment.

Acute Disease↗
PubMed1988

Reproductive and endocrine gonadal functions in adults following multidrug chemotherapy for acute lymphoblastic or undifferentiated leukemia.

The impact of aggressive chemotherapy on reproductive and endocrine gonadal function was studied in ten women and ten men with acute lymphoblastic leukemia (ALL) or acute undifferentiated leukemia (AUL) in complete remission. Hormone determinations, sperm analyses, measurements of basal body temperature, and interviews with a standardized questionnaire were used for diagnostic evaluation. Elevated serum follicle-stimulating hormone (FSH) levels and azoospermia were seen in all male patients after completion of induction and consolidation therapy as a result of germ cell and stem cell loss. Recovery of spermatogenesis, as indicated by normalization of serum FSH values and sperm density, occurred in the second year of maintenance therapy in all men. Serum testosterone and luteinizing hormone (LH) values remained within normal limits indicating resistance of Leydig cells to chemotherapy. All female patients showed normal serum levels of gonadal steroids and gonadotropins, as well as an adequate increase in basal body temperature after intensified chemotherapy, indicating intact follicle function and ovulation. Most patients reported normal sexual functions after induction and consolidation therapy. These results demonstrate that multidrug chemotherapy induced significant impairment of reproductive function in all male patients with early and complete recovery. In contrast, endocrine gonadal function was unaffected in men treated with ALL/AUL. In female patients, neither reproductive nor endocrine functions were influenced by aggressive chemotherapy.

Acute Disease↗
PubMed1988

Norfloxacin for prevention of bacterial infections during severe granulocytopenia after bone marrow transplantation.

48 patients treated with bone marrow transplantation (BMT) received the quinolone norfloxacin (NOR) in a total decontamination (TD-NOR, n = 36) or selective decontamination (SD-NOR, n = 12) regimen and were compared with a historical control group of 48 BMT patients receiving oral non-absorbable antibiotics (TD-NAA, n = 31 and SD-NAA, n = 17). 17/36 patients (47%) of group TD-NOR and 16/31 patients (52%) of group TD-NAA remained free of febrile episodes and infections. 4/12 patients (33%) of group SD-NOR and only 1/17 patients (6%) of group SD-NAA remained free of fever and infections. The use of norfloxacin in selective decontamination resulted in a statistically significant lower incidence of fever days than in patients receiving SD-NAA (p less than 0.001). These data suggest that norfloxacin may replace non-absorbable antibiotics in total and in selective decontamination regimens used for infection prophylaxis in BMT recipients.

Adolescent↗
PubMed1988

Concentration of bone marrow mononuclear cells for in vitro treatment and AB0-incompatible transplantation: a rapid and reproducible procedure using the haemonetics V50 cell separator.

Forty-nine allogeneic and 14 autologous bone marrow grafts were processed with the Haemonetics V50 cell separator (Haemonetics Corp., Braintree, USA) for in vitro treatment with antibodies and cryopreservation respectively. The concentration of hemopoietic progenitor cells was performed without any sedimentation or density gradient agents. The recovery is given in percent (mean +/- sd) of the original marrow values: mononuclear cells (MNC) 74 +/- 10%, polymorphonuclear cells (PMC) 48 +/- 17%, red blood cells (RBC) 12 +/- 5%, granulocyte/monocyte progenitors (CFU-GM) 83 +/- 36%, and erythroid progenitors (BFU-E) 78 +/- 38%. The recovery of nucleated cells (NC) was 90 +/- 13% and the viability 82 +/- 11% after cryopreservation. The technique described provides a simple, rapid and efficient preparation of large bone marrow volumes for in vitro treatment and AB0-incompatible transplantation.

Blood Grouping and Crossmatching↗
PubMed1988

Heterogeneity of insulin and insulin-like growth factor I binding in a human Burkitt type ALL cell line during the cell cycle and in three Burkitt type ALL sublines.

The expression of hormonal and growth factor receptors in leukemic cell lines might be heterogeneous due to the admixture of different cell cycle phases and the presence of yet unidentified sublines. Therefore, cell cycle-specific separation of Burkitt type ALL cells was performed by counterflow elutriation, and by limited dilution procedure three sublines of this cell line were obtained. Counterflow elutriation enriched to 60-80% purity for G1-, S-, and G2-phase which was shown by DNA flow cytometry. Insulin and insulin-like growth factor I (IGF-I) binding was investigated in the G1, S, and G2 phase. Insulin binding sites decreased from 10 to 15,000 per cell in G1 to 1,000-5,000 in S and increased to 40-50,000 in G2. The affinity of insulin binding remained constant during the cell cycle. IGF-I binding sites increased from 2,000 per cell in G1 to 5,000 in S and 15,000 in G2. The affinity of IGF-I binding decreased from G1 toward S and then remained constant in G2. The three isolated clonal sublines differed in numbers of insulin and IGF-I binding sites/cell without differences in affinity. The fact that IGF-I shows higher affinity binding during G1 than during S and G2 Burkitt type ALL cells suggests that IGF-I might be important for initiation of proliferation. The reduction in insulin binding sites during S-phase may indicate refractoriness of the cell to insulin during DNA replication.

Binding Sites↗
PubMed1988

Fractionated total body irradiation and high-dose VP 16-213 followed by allogeneic bone marrow transplantation in advanced leukemias.

Thirty-eight patients (median age, 21 years) with acute nonlymphoblastic leukemia (ANLL) (17 patients), acute lymphoblastic leukemia/lymphoma (ALL) (18 patients), chronic myelogenous leukemia (two patients), and refractory anemia received allogeneic bone marrow transplants from HLA-identical sibling donors or a one-antigen-mismatched brother (one patient) after a preparatory regimen consisting of fractionated total body irradiation and high-dose VP 16-213 (60 to 70 mg/kg body weight). Of the 33 patients with acute leukemia who received grafts from HLA-identical donors, three patients with ANLL received transplants in first remission and one patient with standard-risk ALL received a graft while in second remission. All other patients were in more advanced stages of their disease or exhibited other high-risk features. At the time of analysis, 20 of the 33 patients were alive, with 19 of them remaining in continued complete remission for 6 to 35 months (median, 18 months). The 3-year actuarial disease-free survival rate of 56.6% +/- 9.7% (SE) and the actuarial relapse rate of 11.9% +/- 6.8% (SE) demonstrate that the combination of fractionated total body irradiation and high-dose VP 16 is an effective mode of therapy in patients with advanced leukemias. Preliminary experience cautions against the use of VP 16 instead of cyclophosphamide in any clinical situation carrying an increased risk of graft rejection because the immunosuppressive potency of VP 16 is largely untested but may be inferior to that of cyclophosphamide.

Adolescent↗
PubMed1987

Cytomegalovirus (CMV) infections in patients receiving CMV-IgG-hyperimmunoglobulin prophylaxis after bone-marrow transplantation.

Conditioning therapy with aggressive chemotherapy and irradiation induces a state of transient combined immunodeficiency in bone-marrow transplant recipients. This promotes the occurrence of severe cytomegalovirus (CMV) infections, the most frequent lethal complication after bone-marrow transplantation (BMT) at present. Forty-four BMT recipients received CMV-IgG-hyperimmunoglobulin for CMV prophylaxis intravenously. The efficacy of this prophylaxis and possible risk factors for the occurrence of CMV-induced interstitial pneumonia (IP) were analyzed. Risk factors for the promotion of a CMV-IP were: additional immunosuppressive therapy after BMT, CMV-positive serostatus of the recipient, CMV-seropositive granulocyte transfusion, CMV infection immediately prior to BMT, and HLA-haploidentical BMT. In this study the incidence of graft-versus-host disease was low and was not associated with the incidence of CMV infections. The use of T-cell-depleted grafts did not result in increased CMV infections or IP and may possibly have improved the immunological reconstitution.

Adolescent↗
PubMed1987

[Immunosuppressive therapy in panmyelopathy. Experiences with various forms of therapy in 42 patients].

Immunosuppressive treatment according to four different regimens was administered over the course of eight years to 42 patients with aplastic anemia. With treatment protocols which included horse-ALG and horse-ATG, remissions were achieved in most patients, while with rabbit-ATG improvement was obtained, but only minimally, in 15 patients. First results with Cyclosporin A confirmed the effectiveness of this immunosuppressive agent in the treatment of aplastic anemia. The development of remission was, independently of treatment schedule, recognizable 23-88 days after onset of treatment. Often only partial remission was achieved. The long-term course, especially also survival, correlated with the results achieved within the first three months after onset of treatment. Recurrences occurred in 19% of patients but responded to repeated immunosuppressive treatment if preceded by complete remission. Side-effects to ALG and ATG occurred only during the first two weeks and were easily controllable. In some cases Cyclosporin A led to subjectively distressing side-effects.

Anemia, Aplastic↗
PubMed1987

Blood group change in a patient with blastic transformation of a myelodysplastic syndrome.

Loss of certain red blood cell antigens has been described in patients with acute myelocytic leukemia (AML). This paper describes the loss of blood group A antigen in a patient with AML. The acute leukemia in this patient was preceded by a myelodysplastic syndrome for several months. At the time of diagnosis the patient's red cells showed the 0 Rh(D)+ phenotype. After induction of complete remission with two courses of Daunorubicin, Cytosin-arabinosid, and Etoposid his blood group reverted to A2. Serological studies including saliva analysis revealed that the original blood group was very likely A.

ABO Blood-Group System↗
PubMed1987

Evidence for the involvement of host-derived OKT8-positive T cells in the rejection of T-depleted, HLA-identical bone marrow grafts.

The recent introduction of a variety of techniques for removing T cells from bone marrow grafts has reduced the incidence of graft-versus-host disease (GVHD)-associated morbidity and mortality. Whether this advance will be translated into improved patient survival is unclear at present, mainly because these procedures increase the risk of graft failure. Since 1983 we have transplanted 25 consecutive leukemia patients with HLA-identical sibling grafts purged of T cells by a single incubation with the monoclonal antibody Campath-1 and donor complement. This approach was successful in reducing T cell contamination of the graft and preventing acute and chronic GVHD. In this group of patients two suffered irreversible graft failure and one developed reversible graft failure. In a similarly sized group of patients previously transplanted with unpurged marrow according to the Seattle protocol, no episodes of graft failure occurred. Since other causes of graft failure, such as drug toxicity or viral infections, could be largely excluded, this suggested that the graft failures were specifically related to the purging process. In haploidentical bone marrow transplantation (BMT) O'Reilly has identified residual host-versus-graft activity (HVG) as a cause of graft failure. The causes and mechanisms of graft failure in T-depleted HLA-identical sibling transplants have not been extensively investigated to date. In the three graft failures observed by us, the loss of the graft was preceded by the appearance of a population of activated lymphocytes. We have determined the phenotype and origin of this population and investigated its interactions with donor hemopoietic tissue in vitro.

Antigens, Differentiation, T-Lymphocyte↗