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Biomedical subjects

D Niethammer

Publications and source records attributed to D Niethammer.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Effects of granulocytes on human neuroblastoma cells measured by chemiluminescence and chromium-51 release assay.

We investigated whether polymorphonuclear leukocytes (PMN) are able to kill human neuroblastoma cells either directly or if coated with antibody MAb 14.18 that recognizes ganglioside GD2 present on the cell surface of most neuroblastoma cells. Neuroblastoma cells could not be destroyed directly, whereas in the antibody-dependent reaction (ADCC-reaction) they were easily eliminated. In order to answer the question whether reactive oxygen intermediates are involved in this process, chemiluminescence measurements were performed. Compared to the signals that could be measured using opsonized zymosan as stimulus, only weak CL-signals could be registered during the ADCC reaction. Pretreatment of PMN with granulocyte-macrophage colony stimulating factor (GM-CSF) enhanced the CL-signals, catalase and SOD reduced it; however, cell killing was only slightly influenced in the presence of catalase and superoxide dismutase. These data suggested that reactive oxygen compounds do not play a prominent role in the killing process. Definitive evidence for this suggestion could be obtained using PMN from a patient with chronic granulomatous disease (CGD): MAb 14.18 coated neuroblastoma cells could be killed effectively, but no CL-signal could be registered, either in the ADCC-reaction or using opsonized zymosan as stimulus.

Catalase↗
PubMedDate not supplied

Measurement of endogenous and TNF alpha-mediated H2O2 production in supernatants of SK-N-SH neuroblastoma cells with an enhanced chemiluminescence assay.

A sensitive peroxidase-dependent luminol-enhanced chemiluminescence (ECL) assay for determination of hydrogen peroxide (H2O2) generation by tumour cells was established. This test system allows determination of H2O2 in concentrations as low as 25 pmol (50 nmol/L) and yields results which are comparable to those obtained using a less sensitive photometric method and a previously described scopoletin fluorescence assay. After 3 h incubation time 10(4) SK-N-SH neuroblastoma cells released 60 +/- 5 pmol H2O2 in the supernatant and this level was significantly (p < 0.025) increased by about 70% in the presence of 5 pmol (100 ng/mL) recombinant tumour necrosis factor alpha (TNF alpha). In contrast, H2O2 production was slightly reduced by TNF alpha at a very low concentration of 0.5 fmol (0.01 ng/mL).

Cell Line↗
PubMedDate not supplied

From combinatorial libraries to MHC ligand motifs, T-cell superagonists and antagonists.

Complete experimental data sets of HLA-ligand motifs and T-cell recognition patterns can be derived from combinatorial peptide libraries. These data provide the exact molecular basis for a fast development of synthetic vaccines, T-cell superagonists and non-peptide antagonists. Patient-specific peptides, peptidomimetics and vaccines of highest reactivity can be derived directly from the data sets via our prediction programme EPIPREDICT. The resulting lead structures may be developed into valuable diagnostics and therapeutic tools for the treatment of viral infections, autoimmune diseases and tumors. As one example, antibody and T cell recognition in the intestinal auto-immune disease, coeliac disease was investigated in more detail concerning the deamidation of gamma-gliadin peptides by tissue transglutaminase 9tTG) leading to autoreactive peptides specific for HLA-DQA1*0501, DQB1*0201.

Amino Acid Sequence↗
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Costal BCG osteomyelitis presenting as a tumor.

We present the case of an 11-month-old male infant who had been BCG vaccinated as a neonate. At the age of nine months, he developed a localized tumor above his right mamilla. The tumor destroyed the fourth rib and infiltrated the surrounding soft tissue. X-ray and CT scan suggested a malignant neoplasm. Histology, however, showed the typical picture of tuberculosis and Mycobacterium bovis (BCG strain) was isolated from the lesion. Thus, the tumor was caused by an unusual presentation of a costal BCG osteomyelitis which was associated with negative findings in the bone scan.

BCG Vaccine↗
PubMedDate not supplied

Acute mastoiditis--relevant once again.

During recent years, a significantly increased incidence of acute mastoiditis was observed at the University Children's Hospital, Tübingen, Germany (1975-1979: 1.4 patients/year; 1987-1992: 4.2 patients/year; p < 0.05). We therefore reviewed the records of all patients with acute mastoiditis (n = 58) that had been treated at the Children's Hospital between 1975 and 1992 and at the Clinic of Otorhinolaryngology between 1978 and 1992. The male to female ratio was 1.8:1 and 60.4% of the patients were younger than 24 months. Retroauricular swelling was more often observed (n = 49) than protrusion of the pinna (n = 45) and retroauricular redness (n = 38). Streptococcus pneumoniae was the most frequently isolated pathogen. Several factors predisposing for the development of acute mastoiditis were identified. These included withholding antimicrobials for treatment of the preceding episode of otitis media; use of suboptimal agents for therapy of otitis media (penicillin and, possibly, erythromycin ethylsuccinate); and insufficient duration of treatment.

Acute Disease↗
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Isolation and phenotypic characterization of CD117-positive cells.

Mononuclear cells derived from cord blood were stained using the CD1 17-specific, fluorochrome-labeled monoclonal mouse antibody 95C3. Additional staining was performed using an isotype-specific rat-anti-mouse antibody, labeled with supermagnetic microparticles. Target cells were enriched by the technique of magnetic cell separation, MACS. The resulting cell population contained 96.5% (+/-1.7% S.D.) CD1 17-expressing cells (n = 12) with different levels of CD117 antigen expression. Using flow cytometry, two cell populations differing in size were found. A majority (93%) of cells with high forward scatter revealed a phenotype positive for CD117 and CD34. Isolated cells revealed a high fraction of hematopoietic progenitors (16%). The technique presented allows for an alternative approach of stem cell enrichment and might be useful in autologous transplantation of cells with hematopoietic properties.

Antigens, CD34↗
PubMedDate not supplied

[Relapse of childhood ALL, AML and MDS after allogeneic stem cell transplantation can be prevented by donor lymphocyte infusion in a critical stage of increasing mixed chimerism].

BACKGROUND: Mortality in children with acute leukemias or MDS after allogeneic stem cell transplantation (allo-SCT) is mostly determined by relapses. It was recently shown by us that patients who develop increasing quantities of autologous hematopoietic cells in peripheral blood (increasing mixed chimerism, in-MC) after allo-SCT do significantly more often relapse (P < 0.0001) than patients with a complete chimerism (CC). In a small series of patients with in-MC, the relapse rate could be significantly reduced by administration of donor lymphocytes (DLI). METHODOLOGY: A prospective multicenter study was initiated under the question whether number of relapses can be significantly reduced either by withdrawal of post-transplant immunosuppression and/or by DLI in the critical stage of in-MC. RESULTS: Highly repetitive determination of the genetic status of 114 children with acute leukemias or MDS (ALL: n = 41, AML: n = 39, MDS: n = 34) revealed 55 cases with CC and 43 with in-MC. Relapses occurred significantly (P < 0.0001) more often in patients with in-MC (25/43) than in patients with CC (12/55). In-MC-patients showed a significantly (P < 0.01) enhanced event free survival rate (11/24) when DLI was given and/or post-transplant immunosuppression was stopped compared to patients which did not receive such an interventional regimen (1/19). Two in-MC-patients developed fatal GVHD after immunological intervention. CONCLUSION: These data substantiate that prophylactic immunotherapy on the basis of in-MC is a powerful treatment approach to suppress relapses of acute leukemias and MDS after allo-SCT.

Cause of Death↗
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[Euthanasia and caring for the dying in pediatric oncology].

During the last 30 years pediatric oncology has developed therapeutic schemes for all kinds of tumors. Nevertheless, a third of the children suffering from malignancies have still to die. Therefore it is necessary to develop concepts, how to deal with the death of children and how to care for them and their families during the dying process, because the responsibility for these children does not end at the point of finishing therapy, but at the time of their death. Especially during this last part of life these children and their families need an extremely intensive care. Since most of the children want to die at home, we must also be able to care for them there, possibly in cooperation with a local colleague. This, of course, requires an adequate therapy against pain which is possible in most cases. The basement for an optimal care is to be very open to the children. If this openness is established right at the beginning of therapy it will later serve to cope with difficult situations. "Never to lie" is the most important principle. If the patients are not left alone during the dying process the claim for a final injection will be an exception. However, if euthanasia is required, it is rather an expression of despair and a cry for help. The application of very high doses of medicine, necessary in order to prevent pain, might lead to a shortening of life time. This is neither killing on demand nor euthanasia.

Adolescent↗
PubMedDate not supplied

Infants with stage 4 neuroblastoma: the impact of the chimeric anti-GD2-antibody ch14.18 consolidation therapy.

BACKGROUND: Antibody treatment is considered tolerable and potentially effective in the therapy of neuroblastoma. We have analyzed the clinical data of infants < 1 year with stage 4 neuroblastoma with regard to the consolidation treatment. PATIENTS AND METHODS: Infants < 1 year with stage 4 neuroblastoma who completed initial treatment (6-8 chemotherapy cycles followed either by 4 cycles low dose oral chemotherapy or high dose chemotherapy with stem cell transplantation) without event were eligible for this trial. Consolidation therapy consisted of 6 cycles of antibody ch14.18 (20 mg/m(2) x d ch14.18 for 5 days every 2 months) or 12 months oral maintenance chemotherapy (MT). RESULTS: Of 59 evaluable patients, 31 received a total of 159 ch14.18 cycles, 16 received MT instead, and 12 had no further treatment. Fever (47 % of cycles), abnormal CRP without infection (25 %), rash (23 %), cough (16 %), and pain (8 %) were the main side effects. Univariate analysis found no difference in event free survival (3-year-EFS 80.5 +/- 7.1 %, 87.5 +/- 8.3 %, and 75.0 +/- 12.5 % for patients treated with antibody ch14.18, MT, and no further therapy, p = 0.433) and overall survival (3-year-OS 90.1 +/- 5.4 %, 93.8 +/- 6.0 %, and 91.7 +/- 8.0 % for patients treated with antibody ch14.18, MT, and no further therapy, p = 0.931). Multivariate analysis failed to demonstrate an advantage of antibody treatment. CONCLUSION: The outcome of infants with stage 4 neuroblastoma is good. Consolidation treatment with ch14.18 was tolerable but associated with fever, elevated CRP, rash, cough, and pain as side effects. Compared to oral maintenance chemotherapy and no consolidation treatment, ch14.18 treatment had no impact on the patients' outcome which confirms the results found in children > 1 year.

Administration, Oral↗
PubMedDate not supplied

A comparison between three graft manipulation methods for haploidentical stem cell transplantation in pediatric patients: preliminary results of a pilot study.

Transplantation of hematopoietic stem cells from mismatched related donors makes a potential donor available for every child in need of stem cell transplantation. Here, we compare three different graft manipulation methods in patients with leukemias and lymphomas: positive selection of stem cells with either CD34 (n = 39) or CD133-coated magnetic microbeads (n = 14) and a new strategy which depletes T- and B-cells through the use of CD3- and CD19-coated microbeads (n = 11). Median purity of stem cells was comparable after CD34 (+)-selection and CD133 (+)-selection, whereas stem cells were only slightly enriched after CD3 (+)/CD19 (+)-depletion (97.5 %, 93.4 % and 1.02 %). Indirect depletion of T-cells by positive selection resulted in 1 x 10 (4) (median) residual CD3 (+)-cells/kg (0.7-3 x 10 (4)). Patients with CD3/CD19-depleted grafts received 3.2 x 10 (4) (median) (0.7-16 x 10 (4)) residual T-cells/kg. Those grafts also comprised NK-cells (median number: 86 x 10 (6)/kg), dendritic cells and monocytes/granulocytes. Primary engraftment of the stem cell products was comparable after CD34- and CD133-selection (85 and 72 %). In the CD3/CD19 group, 91 % had a primary engraftment. After reconditioning, all patients (64/64) were finally engrafted. Patients with CD34-selected or CD133-selected grafts had similar incidences of a GvHD II-IV (3 and 7 %), whereas a GvHD was slightly increased in patients receiving CD3/CD19-depleted cells (27 %). Reconstitution of CD3 (+) T-cells was faster in the CD3/CD19 group than in the CD34 or CD133 group. These preliminary results indicate, that CD3/CD19-selected grafts may be advantageous regarding engraftment and immunoreconstitution. Since effector cell with potential antileukemic activity are cotransfused, such grafts may be suited in particular for patients with insufficient remission.

AC133 Antigen↗
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Adenoviral infections after transplantation of positive selected stem cells from haploidentical donors in children: an update.

UNLABELLED: We present updated results of stem cell transplantation with highly purified stem cells from haploidentical parental donors and infection with human adenovirus (HAdV) post stem cell transplantation (SCT). Survival post SCT is primarily determined by relapse, infections and far less by GvHD or other transplant related mortality. During the immune reconstitution the host is at significant risk for severe viral infections. HAdV infection is especially in children an important complication post SCT, with significant morbidity and mortality despite new antiviral treatment strategies. Although control of infection seems to require T-cells, the characterization of HAdV-specific T-cells post SCT has not been introduced in surveillance and treatment decisions. METHODS: Therefore we evaluated the impact of HAdV-infections on the survival between 1995 and 2004 (n = 63) and studied the occurrence of adenovirus-specific T-cells in children with (n = 9) and without (n = 9) HAdV-infection post allogeneic SCT and in healthy donors (n = 53). After stimulation ex-vivo with HAdV-antigen IFN-gamma secreting T-cells were analyzed by flowcytometry and defined as HAdV-specific T-cells. RESULTS: Until day 180 post SCT the cumulative incidence of all lethal viral infections (HAdV n = 5, cytomegalovirus n = 3, herpes simplex virus n = 1) was 16 % for the whole cohort of patients. Cumulative incidence of HAdV-associated mortality was 8.5 %. Cumulative incidence of all lethal viral infections could be now reduced from 16 % to 8 % in conjunction with new surveillance- and therapeutic-strategies. Children with HAdV-associated mortality all had no specific T-cells, although reconstitution of absolute lymphocyte counts exceeded 300/microl within 30 days post transplant. Patients who cleared HAdV infection had normal frequencies of HAdV-specific T-cells until day 200 post SCT. CONCLUSION: In summary adenovirus specific T-cell reconstitution should be monitored in patients after SCT to limit the use of anti viral chemotherapy and help to identify those patients that would benefit from new therapeutic strategies like adoptive transfer of virus specific T-cells.

Adenovirus Infections, Human↗
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[Improved prognosis of intracranial germ cell tumors by intensified therapy: results of the MAKEI 89 therapy protocol].

Germ cell tumors of the central nervous system are histological identical to the extracranial tumor sites. According to the localisation germ cell tumors of the CNS are different in symptoms, diagnostic approaches, kind and location of metastases and stratification of therapy. Since 1986 patients with intracranial germ cell tumors are registered in the ongoing study for non-testicular germ cell tumors (MAKEI) of the German Society of Pediatric Oncology and Hematology, and are treated in accordance to therapy guidelines for extracranial sites. In MAKEI 89 therapy strategy was revised with a reduction of radiotherapy and an increased cumulative cisplatinum dose from 200 mg/m2 to 400 mg/m2. Patients with germinoma receive after histologic diagnosis radiotherapy consisting of 30 Gy craniospinal irradiation and 15 Gy tumorboost. Malignant non-germinoma receive after diagnosis by tumor marker in CSF and/or serum 2 courses bleomycin 15 mg/m2 day 1-3, Etoposide 150 mg/m2 day 1 + 2 and cisplatinum 20 mg/m2 days 4-8 (BEP), continued by 2 courses Vinblastine 3 mg/m2 day 1 + 2, Ifosfamide 1500 mg/m2 days 1-5 and cisplatinum 20 mg/m2 days 1-5 (VIP), followed by 30 Gy craniospinal irradiation and 20 Gy tumor boost. In teratoma first line therapy is complete resection. In incomplete resected cases adjuvant chemotherapy according to histological grading is administered. Until 31st January, 1993 101 patients (pts) were registered, containing 69 protocol pts. Diagnosis in protocol pts was teratoma in 8 cases, 2 pts died postnatal because of extended disease, 2/8 pts relapsed, but were salvaged by chemotherapy. 40 pts offered germinomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗