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Biomedical subjects

F Zintl

Publications and source records attributed to F Zintl.

At least 109 records · Page 6Linked to original sources

[Neurophysiological and biomechanical analysis of a gymnastics accident with high transverse paralysis. An example of a sports medicine research study in the area of prevention of sports accidents].

The development of preventive provisions is an important topic of sport accident research. We demonstrate the stepwise procedure of judging a provision taking the analysis of a gymnastic exercise. This includes determination of the inner and outer reasons of accidents, the biomechanical conditions of the exercise and leads to mathematical and experimental simulation of the dangerous movement. The specific exercise we studied was the efficiency of a coach in protecting position for the handstand somersault with 1 1/2 breakneck leap. The reaction ability of the coach during the exercise and his force capacity to prevent an accident is explored by a newly developed reaction time analyzer and by a catapult apparatus throwing a dummy. Our results show the inadequacy of the prevention provision of a coach in protecting position for the special gymnastic exercise.

Accident Prevention↗

[Cryopreservation of bone marrow for the autologous transplantation in children].

In preparing the autologous transplantation of children a method for cryoconservation of bone-marrow was developed by means of investigating the donor's bone-marrow. This method is adapted to our conditions, can easily be practised and is cell-preserving. Quantity and quality of the stored bone-marrow cells were evaluated concerning their proliferation capability by means of CFU-c assays. The highest recovery in CFU-c (78%) and cells (98%) was observed if isolated mononuclear cells with cryoprotective addition of 5% DMSO, 20% of human albumin, and 20% of serum were slowly frozen at a controllable rate, stored in liquid oxygen and thawed very quickly. According to the elaborated method the remission marrow was taken from 15 children affected with malignant diseases for autologous reinfusion. The data gained here confirm the experimental experiences.

Adolescent↗

[Lysis of leukemia cells with a monoclonal antibody-cocktail (e.g. VIP-pool) and human complement].

During the lysis of leukemic cells with a monoclonal antibody cocktail (the so-called VIB pool) and complement the attempt was made to replace rabbit serum as a complement source by human serum. For identifying the lysis of leukemic cells the complement-dependent in vitro cytotoxicity test was used and for excluding stem cell toxicity the CFU-c test according to PIKE and ROBINSON. In combination with the applied monoclonal antibody pool against B and c-ALL the human complement could be shown to be suitable to produce a lysis in the same manner as rabbit complement. Similarly to the pretested rabbit serum the treatment with the human complement had no impact on stem cell recovery. An optimal cytotoxic activity (95% against ALL blasts of patients, 100% against NALM) could be identified up to an antibody dilution of 1:32 with a volume percentage of 50% of human complement, an incubation temperature of at least 37 degrees C and an incubation time of 30 mins. With proved high reactivity against leukemic cells and lacking impairment of the haemopoietic power of the bone-marrow, this method can be recommended for "purging" protocol with the possibility of using human serum as a source of complement having advantages as far as clinical application is concerned.

Animals↗

[Use of human albumin as an additional cryoprotective agent in freeze preservation of hematopoietic stem cells].

14 bone-marrow samples of healthy donors were cryopreserved with 5% of DMSO in combination with different volume percentages of 20% human albumin, with the protective impact of the respective freezing mixture on the proliferating capacity of early hemotopoietic precursor cells being determined by means of CFU-c-technique. A combination of 5% of DMSO with 20% of human albumin with an addition of 20% of autologous serum proved to be the most favourable freezing protection. CFU-c-recovery which was achieved in this way amounted to 78 +/- 7%. A protective impact of human albumin for CFU-c during incubation with the freezing medium at room temperature was statistically not significant. Thus, the method presented is suitable for cryopreservation of bone marrow for autologous transplantation. The advantages over the traditional procedure results from the slight degree of toxicity by reducing the DMSO percentage from the common 10% to 5% as well as from the fact that the thawed cell suspension may be directly infused with the substance for freezing protection, thus avoiding an additional loss of proliferative material. The procedure may be used especially for autologous transplantation in childhood.

Adult↗

[Elimination of T lymphocytes from the bone marrow in HLA-incompatible bone marrow transplantation].

The method presented is very well suited to eliminate T-lymphocytes from great amounts of bone-marrow. The stem cells required to reconstitute the bone-marrow are enriched in this way. It can be completely performed in a closed system. Any contamination with germs is excluded. It can be reproduced well and learnt quickly. It takes 10 hours for two trained co-workers to process 1,500 ml of bone-marrow. The vitality of cells is very good (100%). Its suitability for transplantation has still to be checked.

Bone Marrow Cells↗

[Detection of glucocorticoid receptors in leukemia cells by dexamethasone-induced cytolysis and [3H]-dexamethasone binding].

The presence of glucocorticoid receptors on the leukemic cells of 33 patients affected with acute lymphatic leukemia (ALL) and 6 patients affected with acute myeloic leukemia (AML) was investigated by dexamethasone-induced cytolysis and [3H] dexamethasone binding. The tests undertaken proved that after 20 hours of incubation 9 of 26 non-T-non-B-ALL (c-ALL and unclassified ALL) and 2 of AML were lysed with dexamethasone; blood lymphocytes and bone marrow leukocytes of healthy donors, however, were not affected. Non-T-non-B-ALL and AML were able to bind essentially more [3H] dexamethasone than T-ALL. There existed no correlation between dexamethasone binding and dexamethasone-induced cytolysis.

Cell Survival↗

[NK and K cell activity in children with leukemias and aplastic anemias before and after allogeneic bone marrow transplantation].

Mononuclear leukocytes from the peripheral blood and bone-marrow of children affected with aplastic anemia and leukemia were investigated for K-cell activity (antibody-dependent cellular cytotoxicity) and NK-cell activity before and after allogenous bone-marrow transplantation. 51Cr liberation test against murine Graffi erythroblast leukemic cells covered with xenoantibodies and K-562 cells were used for identification. Strongly lowered NK- and K-cell activities could be found in aplastic anemia prior to bone-marrow transplantation. However, NK-cell activity was only lowered significantly in leukemic patients with indication of bone-marrow transplantation. K-cell and NK-cell activities normalised after bone-marrow transplantation. K-cell and NK-cell activities could be observed to be reconstituted very early after bone-marrow transplantation.

Anemia, Aplastic↗

Diagnostics and therapy of non-Hodgkin lymphomas in childhood.

Many changes have taken place in the diagnosis and treatment of non-Hodgkin-lymphomas in childhood during the last years. From 1979 to 1982, the Working Group for Paediatric Haematology, Oncology and Immunology of the GDR treated 50 children with NHL according to the LSA2L2-protocol in a multicentric study. The Kiel-classification was applied for histological diagnosis. Main localizations were the mediastinum and abdomen. The treatment resulted in a complete continuous remission of 65% (Stages I and II: 87%, Stages III and IV: 53%) for all patients, independently of the stage. Patients with extranodal tumours and wide-spread abdominal disease had a very bad prognosis with this protocol.

Age Factors↗

[Spontaneous lymphocyte-mediated cytotoxicity and antibody-dependent cell cytotoxicity of human effector cells].

Antigen dependent cellular cytotoxity (ADCC) and non-killer cell activities of haematological healthy donors were investigated in the 51Cr release test. Attempts of cell fraction reveal that lymphocytes are active as killer and non-killer cells. Granulocytes were efficient effector cells of antigen dependent cellular cytotoxity (ADCC), however, they had no natural-killer activity. In testing leukocyte fractions of 11 donors, killer cell would only be found in the non-T-fraction. In contrast to that, three types could be observed in the distribution on non-killer cells: Distribution on T-lymphocyte fraction (27.3%), distribution on non-T-lymphocyte fraction (9.1%) and approximately equal distribution on T- and non-T-lymphocyte fraction 63.7%). Without any treatment patients with acute lymphocytic leukemia showed an antigen dependent cellular cytotoxity and non-killer activity only in exceptional cases. Normal activities were reached in remission, with chemotherapy having a depressive effect on non-killer activity.

Antibody-Dependent Cell Cytotoxicity↗