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Biomedical subjects

D Niethammer

Publications and source records attributed to D Niethammer.

At least 163 records · Page 9Linked to original sources
PubMed1990

Susceptibility of multidrug-resistant human leukemia cell lines to human interleukin 2-activated killer cells.

Considering the possibility to overcome drug resistance by other treatment strategies than chemotherapy we investigated the susceptibility of three independently selected multidrug-resistant sublines of the T-lymphoblastoid leukemic cell line CCRF-CEM to lymphokine-activated killer (LAK) cells. We found that two of the multidrug-resistant sublines were significantly less susceptible targets to LAK cells. A third one, however, was as susceptible as the parental CCRF-CEM cell line. Moreover, a multidrug-resistant subline that reverted to an almost drug-sensitive phenotype was observed to be also revertant for resistance against LAK cells. We found an inverse relationship between the expression of the mdr1 gene (P-glycoprotein) and the susceptibility to LAK cells. Verapamil, a calcium channel blocker, while increasing the drug sensitivity of a multidrug-resistant subline, did not induce a reversal of the suppression of LAK susceptibility. The possibility of enhanced resistance to LAK cells of multidrug-resistant cells should be taken into account when one is looking for therapy strategies to overcome multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Reduction of N-myc expression by antisense RNA is amplified by interferon: possible involvement of the 2-5A system.

Expression of myc-box genes can be reduced by Interferon (c-myc in Daudi cells) or Retinoic acid (N-myc in neuroblastoma cells). Interferon did not reduce N-myc expression in neuroblastoma cells. However, after transfection of the human neuroblastoma cell line LS with a vector, providing the Cadmium inducible expression of an antisense N-myc transcript, drastic reduction of N-myc RNA was achieved in these cells by incubation with Cadmium and Interferon. Treatment with Cadmium alone resulted in a comparably small reduction of N-myc transcripts in these cells. Interferon alone did not appreciably affect N-myc expression. Reduction of N-myc was accompanied with reduced cell proliferation and morphological differentiation. It is assumed that most of the inhibitory effects observed are mediated by the Interferon inducible 2-5A system.

2',5'-Oligoadenylate Synthetase↗
PubMed1990

[Highly malignant non-Hodgkin's lymphoma in hyper-IgE syndrome].

A largely symptom-free swelling of the right submandibular lymph nodes developed in a 23-year-old woman with hyper-IgE syndrome who had suffered from recurrent staphylococcal abscesses since childhood. Histological examination of the lymph nodes revealed highly malignant non-Hodgkin lymphoma of centroblastic type. Extensive staging tests did not reveal any further tumour manifestations. Because granulocyte chemotaxis is abnormal in hyper-IgE syndrome and the patient also had an infection of an old lung cyst, treatment was restricted to local radiotherapy of the cervical lymph nodes. Since 12 months there has been no recurrence. There is probably no connection between the hyper-IgE syndrome and the development of a malignant non-Hodgkin lymphoma, judging by the results of immunological and immunoelectrophoretic findings.

Adult↗
PubMed1990

Vasoactive intestinal polypeptide (VIP) induces calcium mobilization in the human neuroblastoma cell line SK-N-SH.

Release of catecholamines, a Ca2(+)-dependent process, is the most useful biochemical marker in the diagnosis of neuroblastoma. Unfortunately, its stimulus is still unknown. We found that vasoactive intestinal polypeptide (VIP), in addition to acetylcholine and muscarine (but not nicotine), causes elevation of the cytoplasmic Ca2(+)-concentration in the highly differentiated human neuroblastoma cell line SK-N-SH, with or without the presence of extracellular Ca2+. Additionally, VIP was detected in SK-N-SH cells (0.65 ng/10(6) cells). Based on these observations and the fact that neuroblastoma is not innervated in vivo, we hypothesize that in this tumor VIP is responsible for Ca2(+)-dependent release of catecholamines in an autocrine or paracrine fashion.

Acetylcholine↗
PubMed1990

[The importance of preoperative chemotherapy and radiotherapy in 373 children with Wilms' tumor].

Between 1980 and 1988, in a prospective study of 373 children with Wilms' tumour throughout the Federal Republic of Germany, the results of various pre- and postoperative treatment schedules were analysed. There were 184 boys and 189 girls, mean age 3 11/12 (0-27) years. One third each was in group I, II or III-V, respectively. In 52% of cases the tumour volume, measured by ultrasound, was more than 400 ml. 218 of the children were called protocol patients, the remaining 155 served as observation patients, because the latter had histological variants or there had been marked treatment deviations. The stage-adapted treatment always included operation, in 30% of children after pre-operative chemo- or radiotherapy. Radiotherapy was given in selected patients in stage II and always to those in stages III, IV or V. Chemotherapy consisted of Actinomycin D and vincristine, adriamycin was added for stages III-V and cyclophosphamide or ifosfamide for histologically highly malignant variants. Of the 218 protocol patients 196 (90%) were alive without recurrence, after a mean observation time of more than 7 years. Radiotherapy was given to only 105 of the 218 protocol patients. The prognosis of the 155 observation patients differed according to the histology: those with clear-cell type had a better prognosis than previously reported. Among the total group of 373 patients 305 (81.8%) have remained without recurrence after more than 6 years.

Adolescent↗
PubMed1990

In vitro and in vivo effect of interleukin-2 on the 2',5'-oligoadenylate synthetase activity of peripheral mononuclear blood cells.

The in vitro and in vivo influence of interleukin-2 (IL-2) on 2',5'-oligoadenylate (2-5A) synthetase activity and natural killer (NK) activity of peripheral mononuclear blood cells (PBMCs) was investigated. Incubation of PBMCs in vitro with IL-2 resulted in a considerable secretion of interferon-gamma (IFN-gamma) and in a significant elevation of 2-5A synthetase activity, as well as NK activity. Neutralizing monoclonal anti-IFN-gamma antibodies inhibited the elevation of 2-5A synthetase activity, but not the IL-2-induced augmentation of NK activity. Additionally, 2-5A synthetase and NK activity of PBMCs was measured in a child with neuroblastoma that was treated with recombinant IL-2 by continuous intravenous application. During the treatment, NK activity against the NK-sensitive cell line K 562 and against autologous tumor cells was not augmented. However, a significant increase of 2-5A synthetase activity in PBMCs was observed during IL-2 treatment, whereas there was no detectable serum level of IFN-gamma. We conclude that measuring 2-5A synthetase activity in patients treated with IL-2 may be helpful in monitoring the immunomodulatory effects of IL-2 on immune effector cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1990

8-Methoxypsoralen and ultraviolet A therapy for cutaneous manifestations of graft-versus-host disease.

The potentially beneficial effect of 8-methoxypsoralen and ultraviolet A (PUVA) irradiation for treatment of drug-resistant cutaneous manifestations of graft-versus-host disease led us to investigate the effect of this therapy in a larger series of patients with GvHD. To date, 11 patients with histologically demonstrated cutaneous GvHD (acute GvHD grade III-IV in 4 patients, extensive lichenoid chronic GvHD in 6 patients, sclerodermatous chronic GvHD in 1 patient) have received PUVA treatment for 2-24 weeks. All patients have been on CsA for GvH prophylaxis; 5 with mismatched grafts had additionally received methotrexate or monoclonal antibody campath-1 after bone marrow transplantation. Seven patients were on CsA and prednisolone; 2 patients on CsA, prednisolone, and azathioprine; 1 patient on azathioprine and prednisolone; and 1 patient had no immunosuppressive treatment for the duration of PUVA treatment. The 8-methoxypsoralen (0.6 mg/kg bw) was given as photosensitizer before each ultraviolet A irradiation (0.3-8.5 joules/cm2). The only observed adverse reaction was mild nausea. In all patients improvement of cutaneous lesions could be observed with complete response in 5 patients and partial response in 6 patients. Immunosuppressive drugs could be withdrawn in 2 patients and reduced in 8 patients after initiation of PUVA treatment. These findings suggest that PUVA therapy may be a useful adjunct to conventional therapy for cutaneous GvHD.

Adolescent↗
PubMed1990

Release of iron from ferritin by 6-hydroxydopamine under aerobic and anaerobic conditions.

6-hydroxydopamine (6-OHDA) proved to be a very effective agent for iron release from ferritin. Iron release was enhanced in the presence of SOD, catalase and under anaerobic conditions. Ascorbic acid, a well known agent able to release iron from ferritin, increased the amount of released iron in more than an additive manner when used in combination with 6-OHDA. Similar to 6-OHDA, 6-hydroxydopa (Topa) and 1,2,4-benzenetriol were also able to release iron in large amounts; in contrast, catecholamines and other benzenediols were comparatively ineffective.

Aerobiosis↗
PubMed1990

Bone marrow transplantation in comparison with conventional therapy in children with adult type chronic myelogenous leukemia.

From 1983 to 1988 14 patients under 16 years of age with adult type chronic myelogenous leukemia (CML) in chronic or blastic phase were treated by allogeneic bone marrow transplantation (BMT) in our center. These comprise 54% of all patients under 16 years of age grafted for this disease in FRG. These BMT patients were compared with 24 similar patients treated conventionally with busulfan and/or hydroxyurea in various centers. The probability of an event-free survival 5 1/2 years after BMT was 0.61 (SD 0.16); the estimated probability of survival for 3-8 years after diagnosis in the group treated by GMT was 0.78 (SD 0.14) vs 0.55 (SD 0.12) for the non-BMT group. The difference is not significant. In the BMT group only two patients died of transplant-related complications. The non-BMT patient with the longest survival period died recently 10 years after diagnosis. For children with adult type CML, BMT is a safe and effective treatment, and should be recommended if there is an HLA compatible sibling donor or even a fully compatible unrelated donor. However, for a more conclusive comparison between bone marrow transplantation and conventional treatment a longer observation period and larger patient numbers are necessary.

Adolescent↗