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Biomedical subjects

B Speck

Publications and source records attributed to B Speck.

At least 19 recordsLinked to original sources
PubMed1992

[Swiss Register for unrelated bone marrow donors: preliminary results].

Bone marrow transplantation from the unrelated volunteer donor is today a realistic possibility for patients lacking an HLA-identical family donor. In 1988, the Swiss Unrelated Bone Marrow Donor Registry was founded to coordinate such bone marrow transplants and create the Swiss volunteer donor registry. Thus for a search has been initiated for 71 patients and 16 transplants have been performed. Donor and recipient were HLA-A-, -B- identical by serology and HLA-Dr-identical by DNA-oligotyping. 10 of the 16 patients are alive without signs of basic disease 2 weeks to 2 years and 4 months after the transplant. These results illustrate that unrelated donor transplantation, using careful selection criteria, is a realistic new therapeutic modality.

Adolescent↗
PubMed1992

Morphology in patients with severe aplastic anemia treated with antilymphocyte globulin.

One hundred and seventeen patients with severe aplastic anemia (SAA) were treated at our institution between 1976 and 1990 with antilymphocyte globulin (ALG) therapy. Seventy-nine (68%) are alive and probability of survival at 14 years, according to Kaplan and Meier, is 62% +/- 12%. Twenty-six patients developed a late clonal complication: 11 had a myelodysplastic syndrome (MDS) and 17 had paroxysmal nocturnal hemoglobinuria (PNH); two patients had both. The cumulative risk at 10 years is 42%. The development of MDS/PNH after SAA directly affects survival. The probability of being alive at 14 years is 81% +/- 10% for patients with stable disease and 36% +/- 13% for those with clonal evolution (P = .001). To look for predictive signs, we reevaluated peripheral blood and bone marrow cytomorphology at presentation, during regeneration, and in remission. We examined the peripheral blood values for hemoglobin, reticulocytes, granulocytes, thrombocytes, mean corpuscular volume (MCV), and fetal hemoglobin, as well as bone marrow for cellularity, erythropoiesis, myelopoiesis, and megakaryopoiesis. ALG therapy induces slow and incomplete recovery. Although in "remission," ALG patients have lower hemoglobin values, higher reticulocyte counts, lower granulocyte and platelet values, and a higher MCV and fetal hemoglobin than normal controls. They retain a reduced number of megakaryocytes and a persistence of atypical monocytes in bone marrow morphology as stigmata of their disease. Patients with late clonal complications show distinct morphologic abnormalities: patients with PNH have higher MCVs, higher granulocyte and reticulocyte counts, and more dyserythropoiesis at diagnosis and a lower hemoglobin with an increased proportion of erythroblasts in the bone marrow in "remission." Patients who later developed MDS are not different from the total patient population at diagnosis. After therapy, these patients are characterized by the presence of ring sideroblasts and atypical monocytes during regeneration and by a persistent increase in MCV, a higher fetal hemoglobin, lower granulocyte values, and megakaryocytic dysplasia during "remission." Thus, routine morphologic follow-up examination of blood and bone marrow can discover patients at risk for late hematologic complications after ALG therapy.

Adult↗
PubMed1992

Stem cell factor stimulates the in vitro growth of bone marrow cells from aplastic anemia patients.

Aplastic anemia (AA) is a rare human bone marrow disorder of unknown etiology manifested by a strongly impaired growth of hematopoietic precursors. In this study, we examined the ability of recombinant human stem cell factor (SCF) to stimulate proliferation in vitro of bone marrow cells from 15 AA patients. All patients had been previously treated with antilymphocyte globulin (ALG). SCF, in combination with erythropoietin (Epo), interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF), increased the number of hematopoietic colonies formed in a semisolid medium by AA marrows. Maximal colony numbers reached 30% of the numbers observed with normal bone marrow cells. Proliferation of AA cells cultured in a liquid medium containing SCF together with Epo, IL-3, GM-CSF, and G-CSF approached 70% of the control level, as measured by 3H-thymidine incorporation. The effect of the combination of SCF with the other growth factors was more than 10 times stronger than that of the growth factors alone. The most marked effect of SCF was on the generation of erythroid colonies by precursor cells. The results demonstrate synergism between CSF and other hematopoietic growth factors, resulting in the most efficient stimulation of the in vitro growth of AA bone marrow cells described to date. Use of SCF, either alone or in combination with other factors, may be of potential value in treatment of AA.

Adolescent↗
PubMed1992

Bone marrow transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia.

Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL) has a poor prognosis when treated with conventional chemotherapy. We analyzed the outcome of 67 HLA-identical sibling bone marrow transplants (BMTs) for Ph1-positive ALL reported to the International Bone Marrow Transplant Registry (IBMTR). Twenty-one of 67 (31%) transplant recipients survived in continuous complete remission more than 2 years after transplant. Two-year actuarial probabilities (95% confidence interval) of leukemia-free survival were 38% (23% to 55%) for 33 patients transplanted in first remission, 41% (23% to 61%) for 22 patients transplanted after relapse, and 25% (9% to 53%) for 12 patients failing to achieve remission with conventional chemotherapy. These data indicate that transplants are effective treatment for Ph1-positive ALL.

Adolescent↗
PubMed1992

[Iron-deficiency anemia: diagnosis and therapy].

Iron deficiency is the most frequent cause of anemia. The correct diagnosis is based on history, peripheral blood findings and investigations of the iron status. Anemia occurs only when iron stores are empty. Iron deficiency anemia is a microcytic, hypochromic anemia. Red blood cells show poikilo- and anisocytosis with predominance of small erythrocytes. In one third of the patients the anemia is accompanied by slight leukopenia. The platelet counts may be normal, increased or decreased. Iron deficiency is documented by decreased serum iron, increased transferrin and decreased iron saturation. Ferritin below 15 ng/ml confirms the depletion of iron. Once the diagnosis of iron deficiency is established, its cause must be investigated. Pregnancy and bleeding are the most frequent conditions leading to iron deficiency. Therapy of iron deficiency involves treatment of the underlying condition as well as reestablishment of iron stores. Oral therapy is the most safe and economical method of correcting iron deficiency. Parenteral therapy should be confined to exceptional situations.

Anemia, Hypochromic↗
PubMed1992

[Significance of the automated blood count].

Modern hematology depends on rapid and accurate determination of quantitative and qualitative blood counts. Fully automated analyzers based on the principles of flow cytometry have replaced the traditional blood smear in the routine laboratory. They count the number of red cells, platelets and leukocytes with high precision. In addition, they divide the cells into different populations according to their physical or chemical properties. This population distribution pattern mimics a "differential" blood smear. Normality can be assessed with a high degree of accuracy, rapidly and reproducibly. The qualitative changes frequently provide pointers to the final diagnosis. In case of abnormalities the reports are flagged. A microscopic analysis should be added according to internal laboratory guidelines. It clarifies pathological findings and is essential in the search for specific abnormalities such as malaria. This underlines the need for exchange of information between physician and laboratory.

Autoanalysis↗
PubMed1992

Recombinant human granulocyte-macrophage colony-stimulating factor accelerates neutrophil and monocyte recovery after allogeneic T-cell-depleted bone marrow transplantation.

In a prospective randomized study, five European transplant centers compared recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; mammalian glycosylated) with placebo. rhGM-CSF was administered in a dose of 8 micrograms glycoprotein (5.5 micrograms protein)/kg/d, as a continuous intravenous (IV) infusion for 14 days, starting 3 hours after bone marrow infusion. Fifty-seven patients entered and completed the study. Median age of the recipients was 34 years (range, 17 to 51 y). All donors were HLA-identical, MLC-nonreactive siblings. Marrow grafts were depleted of T lymphocytes either by counterflow centrifugation (n = 42) or by immunological methods (n = 15). Twenty-nine patients received rhGM-CSF and 28 patients placebo. The leukocyte count and the absolute neutrophil count were significantly higher in the rhGM-CSF-treated group from day +9 to day +14 after bone marrow transplantation (BMT). This was also true for the monocyte count from day +12 to day +21. Early neutrophil (greater than 0.1 and greater than 0.3 x 10(9)/L) and early leukocyte (greater than 0.3 and greater than 0.5 x 10(9)/L) recovery was significantly faster for the patients given GM-CSF. The incidences of graft-versus-host disease (GVHD) and transplant-related mortality were not different in both groups. However, the number of bronchopneumonias was significantly lower in the rhGM-CSF-treated group (P = .03). Long-term follow-up showed a trend to better overall disease-free survival at 2 years and a trend to a lower relapse risk in patients treated with rhGM-CSF. This study shows that rhGM-CSF significantly increases neutrophil and monocyte counts during periods of 6 to 10 days in the second and third week after BMT. This shortened period until myeloid cell recovery after transplantation resulted in a decreased number of pneumonias, without an increase in incidence of GVHD or relapse.

Adolescent↗
PubMed1991

[Immunoglobulin deficiency after repeated plasmapheresis].

In 10 patients with Guillain-Barré syndrome the level of globulins and immunoglobulins before and after plasmapheresis was investigated. As a plasma substitute either PPL (in 8 patients) or a plasma substitute solution rich in immunoglobulins (in 2 patients) was used. When plasma was substituted with PPL, the globulins and immunoglobulins dropped to a mean of 40% of the initial value (range 30-60%) after the first plasmapheresis. With daily or alternate day plasmapheresis, the globulins only partially recovered. Before the second plasmapheresis they were still reduced to a mean of 50% (range 20-50%), and dropped further with ongoing exchanges to a mean of 33% (range 20-50%) as measured before the third plasmapheresis. Accordingly, there was a loss of immunoglobulins of similar magnitude. With the use of a plasma substitute solution rich in immunoglobulins (IRP), globulins could be maintained at normal levels. The lowest immunoglobulin values measured after plasmapheresis were 6 g/l (normal range 8-17 g/l). One patient developed gram-negative septicaemia after plasmapheresis with PPL, possibly due to a low immunoglobulin concentration. We conclude that a plasma substitute solution rich in immunoglobulins should be used for therapeutic plasmapheresis in order to maintain physiological immunoglobulin concentrations.

Adult↗
PubMed1991

Neutrophil function and pyogenic infections in bone marrow transplant recipients.

In a consecutive entry trial, the incidence and time course of decreased neutrophil function was assessed in 20 patients treated with allogeneic bone marrow transplantation (BMT). The aim of the study was to assess the prognostic value of low neutrophil function for late pyogenic infections. Chemotaxis, superoxide production, and phagocytic-bactericidal activity were studied before and 2, 6, 9, and 12 months after BMT. Skin window migration was quantitatively assessed 2 months after BMT. Infectious complications were recorded prospectively with preset criteria during 1 year. Six of the 20 leukemic patients had defective neutrophil function before BMT. Two months after BMT all 10 patients with greater than stage II graft-versus-host disease (GVHD), and 6 of 10 patients with less than or equal to stage II GVHD had at least one decreased function. At this time, patients with subsequent pyogenic infections had lower chemotaxis (P less than .05), phagocytic-bactericidal activity (P less than .005), and superoxide production (P less than .025) than those without. Defective skin window migration and combined defects were predictive for late pyogenic infections. At 9 months all tests were normal in seven patients surviving without GVHD. In contrast, at 9 months three of three patients, and at 1 year two of three with chronic GVHD had still decreased neutrophil function. In conclusion, neutrophil function is frequently impaired during the first months after BMT. Combined neutrophil defects predispose to pyogenic infections and indicate the patient at risk.

Blood Bactericidal Activity↗
PubMed1991

Effect of fleroxacin and ciprofloxacin on the formation of human mature colonies of healthy donor versus transplanted hemopoietic progenitor cells.

The effect of fleroxacin and ciprofloxacin on hemopoietic progenitor cells was tested in vitro. Cryopreserved bone marrow samples from 5 patients with acute myeloid leukemia who underwent bone marrow transplantation as well as samples from the respective donors were investigated in parallel. Regarding burst and/or colony formation by erythroid, neutrophil and macrophage precursors, no significant differences were detected with donor and transplanted bone marrows between control cultures and cultures containing 100 mg/l fleroxacin, while 100 mg/l ciprofloxacin inhibited cell proliferation completely. At 50 and 10 mg/l ciprofloxacin had a 50% and no inhibitory effect, respectively.

Bone Marrow Cells↗
PubMed1991

Hematologic values of New Zealand white rabbits determined by automated flow cytometry.

Hematologic values of peripheral blood from normal adult New Zealand White rabbits were determined by five different automated flow cytometers in use in a routine clinical hematology laboratory: Technicon H1, Coulter Counter CC540, Coulter Counter VCS, Sysmex NE8000 and Sysmex R1000. The software designed for human blood analysis was used in all instances without adaptation. The total numbers of white blood cells, red blood cells, reticulocytes and platelets were measured with high precision and accuracy. Except for hemoglobin content, concordance was excellent for all measured and calculated values among the different automated flow cytometers. Determining the white blood cell differential count was more complex. Eosinophils and lymphocytes were quantified reliably by all the automated flow cytometers used. However, the results were rejected by Technicon H1 and Sysmex NE8000 in 50% of the cases. Rabbit basophils were recognized with accuracy by Technicon H1 only. The proportion of polymorphonuclear versus mononuclear white cells was identical when measured with Technicon H1 and Coulter Counter VCS. These results show that the new generation of automated flow cytometers designed for human blood can be used with some limitations for animal studies. They allow the standardization of normal values and comparison of results among or between laboratories. They also introduce new parameters, the value of which is as yet undefined.

Animals↗