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Biomedical subjects

M Pfreundschuh

Publications and source records attributed to M Pfreundschuh.

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

Antitumor effects of ricin A chain immunotoxins prepared from intact antibodies and Fab' fragments on solid human Hodgkin's disease tumors in mice.

Three monoclonal antibodies which strongly bind to Hodgkin and Reed-Sternberg cells and two corresponding Fab' fragments were linked to deglycosylated ricin A chain (dg A) to evaluate their potential as immunotoxins for the treatment of Hodgkin's disease. Two of the antibodies, Ber-H2 and HRS-3, were shown to bind to the same epitope on the CD30 antigen, whereas the third antibody, IRac, bound to a different antigen. None of the antibodies significantly cross-reacted with normal human tissues as judged by indirect immunofluorescence and immunoperoxidase analyses on frozen sections from 28 normal tissues. All three antibodies formed potent and specific immunotoxins. They inhibited protein synthesis of the L540 Hodgkin's disease cell line in vitro by 50% at concentrations of 1 x 10(-11) M for IRac.dgA, 9 x 10(-11) M for HRS-3.dgA, and 2 x 10(-10) M for Ber-H2.dgA. HRS-3 Fab' and IRac Fab' immunotoxins were 7.8- and 60-fold less cytotoxic, respectively, than their intact counterparts in vitro. In vivo, a single i.v. injection of a dose of Ber-H2.dgA, HRS-3.dgA, or IRac.dgA corresponding to 40% of the LD50 induced lasting complete remissions in 38, 44, and 50%, respectively, of mice with solid s.c. L540 tumors of 60 to 80 mm3 size (0.5-cm diameter). At equivalent dosage (40% of the LD50), the HRS-3 Fab'.dgA and the IRac Fab'.dgA both induced lasting complete remissions in 25% of the mice, although the HRS-3 Fab'.dgA was significantly superior to IRac Fab'.dgA at retarding tumor growth in the remaining animals. The effectiveness of the immunotoxins depended on the size of the tumor at the time of injection, since IRac.dgA treatment induced complete remissions in 100% of mice with small tumors (10 to 20 mm3, approximately 0.3 cm in diameter) but only 13% of mice with larger tumors of 400 to 600 mm3 (approximately 1 cm in diameter). Tumors which regrew after IRac.dgA treatment mainly consisted of antigen-deficient mutants having reduced sensitivity to IRac.dgA but normal sensitivity to HRS-3.dgA. It is concluded that HRS-3.dgA, HRS-3 Fab'.dgA, and IRac.dgA are candidates for the treatment of Hodgkin's disease in humans.

Animals↗
PubMed1990

Evaluation of ricin A chain-containing immunotoxins directed against the CD30 antigen as potential reagents for the treatment of Hodgkin's disease.

Five monoclonal CD30 antibodies and two Fab' fragments were linked to deglycosylated ricin A chain (dgA), and their potential as immunotoxins for the treatment of Hodgkin's disease was evaluated. Cross-blocking experiments demonstrated that HRS-1, HRS-3, HRS-4, and Ber-H2 recognize the same epitope on the CD30 antigen and that Ki-1 binds to a different epitope. Scatchard analyses showed that HRS-3, HRS-4, and Ber-H2 bound strongly to L540 Hodgkin cells (Kd 15, 7, and 14 nM, respectively), whereas HRS-1 and Ki-1 bound more weakly (Kd 160 and 380 nM, respectively). The different affinities of the antibodies correlated closely with their cytotoxic potency as immunotoxins. HRS-3.dgA, HRS-4.dgA, and Ber-H2.dgA inhibited the protein synthesis of L540 cells by 50% at concentrations of 0.9-2.0 x 10(-10) M, whereas HRS-1.dgA and Ki-1.dgA were about 100 times less potent with 50% inhibitory concentrations of 0.8-1.0 x 10(-8) M. The most effective immunotoxins, HRS-3.dgA and HRS-4.dgA, were only 15 times less toxic than ricin itself. HRS-3 Fab'.dgA and HRS-4 Fab'.dgA were 7.8 and 3 times less potent than their IgG.dgA counterparts with 50% inhibitory concentrations of 7 x 10(-10) and 3 x 10(-10) M, respectively. Staining of human tissues revealed an unexpected cross-reactivity of HRS-4 with pancreatic cells of malignant and nonmalignant origin. HRS-1, HRS-3, Ber-H2, and Ki-1 showed very little cross-reactivity with any normal human tissues. It is concluded that HRS-3.dgA and HRS-3 Fab'.dgA are the immunotoxins of choice for in vivo therapy.

Antibodies, Monoclonal↗
PubMed1990

Immunoscintigraphy of Hodgkin's disease: in vivo use of radiolabelled monoclonal antibodies derived from Hodgkin cell lines.

The Hodgkin associated monoclonal antibody (Mab) HRS-1 reacts with Hodgkin and Reed-Sternberg cells (HR-S) in all HD subtypes. HRS-1 Mab was labelled with radioiodine and injected into 10 patients for immunoscintigraphy (IS). Seven patients were injected with HRS-1 Mab radiolabelled with 131I and three patients were injected with HRS-1 Mab labelled with 123I. A control anti-alpha-fetoprotein (anti-AFP) Mab was radiolabelled with another iodine isotope and was injected simultaneously in five cases. Six out of eight patients with proven HD had a true positive scan (nodal, splenic and bony involvement). Imaging was equivocal or failed in the two other patients. In the last two patients IS imaging was truly negative due to the absence of residual HD in one patient and to an erroneous histological diagnosis of HD in another patient. These results, although preliminary, demonstrate that IS with radioiodine-labelled HRS-1 Mab is feasible and may prove to be informative in the staging of HD.

Animals↗
PubMed1990

[Radiotherapeutic quality assurance in the Hodgkin's disease study HD4 supported by the BMFT (Bundesministerium für Forschung und Technologie)].

In the German Hodgkin Study Group a radiotherapy assurance program is being carried out at the radiotherapeutic reference centre in Göttingen since April 1988: 74 patients were entered from 27 radiotherapeutic institutions. 18 of them participated in a quality assurance program and submitted the data of 29 patients: In 21 of the 29 patients the protocol was followed correctly. Physical aspects of quality control showed two major deviations from the protocol: one center used photon energies of more than 15 MVX without mould; another had a anterior-posterior loading of 3:1. The radiation oncology assessment detected six inadequate treatments: The safety margin was inappropriate in three of 26 mantle fields. Another center used a multiple field technique, and in two patients the paraaortic region was not irradiated.

Cobalt Radioisotopes↗
PubMed1990

Phase II study of recombinant human tumor necrosis factor in colorectal carcinoma.

Fifteen patients with colorectal carcinoma received a 30-min intravenous infusion of recombinant human tumor necrosis factor (rHuTNF) to investigate the value of rHuTNF in the treatment of colorectal carcinoma. Patients received 5 x 10(5) U/m2 (217 micrograms/m2) on day 1, and in the absence of serious side effects 10 x 10(5) U/m2 (435 micrograms/m2) on day 3 and 15 x 10(5) U/m2 (652 micrograms/m2) on day 5. The cycle was repeated on day 28. Full dose escalation was possible in all patients. There was a minor response in one patient (disappearance of retroperitoneal lymph nodes). All other patients showed progressive disease. At the dose and schedule used, rHuTNF had minimal therapeutic activity in colorectal carcinoma.

Adolescent↗
PubMed1989

[Update oncology '89. II].

Explore the source record for details and available documents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Radiolabeled monoclonal antibodies against Reed-Sternberg cells for in vivo imaging of Hodgkin's disease by immunoscintigraphy.

The Hodgkin Reed-Sternberg (HRS-1) monoclonal antibody (Mab) was raised against the L 428 Hodgkin's disease (HD) cell line. The HRS-1 Mab was labeled with radioactive iodine and injected into six patients with Hodgkin's disease of varied histological subtypes for immunoscintigraphic imaging. In five patients, the HRS-1 Mab was labeled with 131I; a control anti-alpha-fetoprotein (AFP) Mab was injected simultaneously in two of these five cases. Four of five patients had a positive scan (nodal, splenic and hepatic involvements), the results in the fifth patient being equivocal. In the sixth patient, the HRS-1 Mab was labeled with 123I in order to utilize tomoscintigraphy instead of linear scintigraphy. Although the immunoscintigraphy (IS) was performed secondary to effective chemotherapy, images of bony disease were demonstrated. These preliminary results demonstrate that IS with iodine-labeled HRS-1 Mab is feasible and informative in Hodgkin's lymphoma. The real clinical value and the specificity of IS deserves confirmation in a larger series of patients. Several techniques such as the use of Fab or F(ab')2 fragments should further improve the results.

Adolescent↗
PubMed1989

Risk factor adapted treatment of Hodgkin's lymphoma: strategies and perspectives.

In a national multicenter trial in the Federal Republic of Germany, patients with Hodgkin's lymphoma in stages I, II and IIIA presenting with large mediastinal tumor (MT), extranodal (E), or massive spleen (S) involvement received a combined modality treatment with 2x (COPP + ABVD) followed by 20 or 40 Gy EF radiation (HD1 protocol). By October 1987, 89 patients aged 15-60 years had finished therapy and were evaluable for response. Of these 74 (83%) achieved complete remission (CR). After 3 years freedom from treatment failure (FFTF) is 80% (+/- 8%, 95% confidence interval) and survival (SV) 92% (+/- 6%, 95% confidence interval). In a univariate and multivariate analysis using FFTF as endpoint we could not identify any particularly prominent prognostic risk factor among the following examined: stage, constitutional symptoms, MT, E stage, S involvement, age, sex, histology, laparotomy, erythrocyte sedimentation rate (ESR), leukocytes, lymphocytes, and alkaline phosphatase (AP). These data suggest that the inclusion criteria have selected a fairly homogeneous group of patients with respect to prognosis. In a separate trial (HD3 protocol) patients in stages IIIB/IV received induction chemotherapy with 3x (COPP + ABVD). Patients in complete remission (CR) received consolidation therapy by either radiotherapy (20 Gy IF) or further chemotherapy (COPP + ABVD). Patients not in CR received salvage therapy (40Gy in the case of persisting nodal disease, or else 4x CEVD chemotherapy). By October 1987, 137 patients had finished therapy and were evaluable for response. Of these 86 (63%) achieved CR after induction chemotherapy. Including salvage therapy a total of 104 patients (76%) achieved CR. After 3 years FFTF is 56% (+/- 10%, 95% confidence interval) and SV 84% (+/- 8%, 95% confidence interval). Univariate and multivariate prognostic risk factor analyses were performed using FFTF as endpoint. Sex, age, stage, splenectomy, bone marrow, and liver and bone involvement had no prognostic impact. In contrast, a pretreatment erythrocyte sedimentation rate (ESR) above 80 mm/h and a serum alkaline phosphatase (AP) above 230 IU/ml each appeared as significant prognostic factors (P less than 0.01; relative risk, 2.3). The two parameters can be combined to separate two groups (A: ESR and AP both low; B: ESR and/or AP high) which differ significantly for FFTF (P less than 0.001) and survival (P less than 0.04). The decision for risk-adapted treatment requires identification of groups of patients in the frame of specified diagnostic and therapeutic strategies.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

Chemotherapy of Hodgkin's lymphoma with alternating cycles of COPP (cyclophosphamide, vincristin, procarbazine, prednisone) and ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine). Results of the HD1 and HD3 trials of the German Hodgkin Study Group.

Untreated patients with Hodgkin's lymphoma in stages I-IIIA with risk factors (large mediastinal mass, massive splenic involvement, extranodal disease) were entered into the HD1 protocol and received a combined chemo-radiotherapy [2 X (COPP + ABVD) + 40 Gy extended field irradiation (EF) vs 2 X (COPP + ABVD) + 20 Gy EF]. Patients in stages IIIB/IV (HD3 protocol) received induction chemotherapy [3 X (COPP + ABVD)] and were randomized into consolidation by radiotherapy [20 Gy involved field irradiation (IF)] vs chemotherapy [1 X (COPP + ABVD)]. Seventy-three of 89 evaluable patients (82%) treated according to the HD1 protocol achieved a complete remission. Freedom from progression and survival of patients in stages I-IIIA with risk factors treated according to HD1 were no worse than those of patients in stages I and II without risk factors who received only radiotherapy. Eighty-six of 137 patients (63%) treated according to the HD3 protocol achieved complete remission after induction chemotherapy with COPP + ABVD. This is significantly better than the 31% complete remission rate observed in a previous pilot study with COPP alone (P less than 0.01). Including salvage therapy (radiotherapy in case of persisting nodal disease; chemotherapy with 4 X CEVD in case of persisting disseminated disease), a total of 76% complete remissions in stages IIIB/IVAB were achieved. A high erythrocyte sedimentation rate (greater than 80 mm h-1) was the most significant risk factor for achieving freedom from progression.

Adolescent↗
PubMed1989

Phenotyping of acute myelomonocytic (AMMOL) and monocytic leukemia (AMOL): association of T-cell-related antigens and skin-infiltration in AMOL.

Leukemic blast cells in 25 cases of AMMOL (13 cases) and AMOL (12 cases) were positive for My7 (CD13) and My4 (CD14), while only 44% reacted with LeuM3 (another CD14 MoAb). T-cell-related antigens were detected in 44% of the cases (CD2, 24%; CD4, 12%; CD7 36%). The expression of LeuM3 and TcrAg on blast and monocytic cells was mutually exclusive, with three cases expressing neither LeuM3 nor TcrAg. All six patients with myeloperoxidase negative AMOL and the TcrAG+/LeuM3- phenotype had leukemic skin infiltrations.

Adult↗