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Biomedical subjects

J Ritter

Publications and source records attributed to J Ritter.

At least 199 records · Page 11Linked to original sources
PubMed1989

Combination chemotherapy in malignant non-seminomatous germ-cell tumors: results of a cooperative study of the German Society of Pediatric Oncology (MAKEI 83).

In January 1983, the German Society of Pediatric Oncology started a cooperative trial (MAKEI 83) for non-testicular germ-cell tumors. The pilot phase closed in December 1985. The treatment regimen was stratified according to histology, tumor site and tumor stage. In malignant non-seminomatous germ-cell tumors (mNSGCTs), chemotherapy consisted of four courses of 3 mg/m2 vinblastine, on days 1 and 2 and 15 mg/m2 bleomycin on days 1-3, given by continuous infusion, and 20 mg/m2 cisplatin on days 4-8 with mannitol diuresis. Courses were repeated every 3 weeks. In mNSGCT patients with ovarian FIGO stages III-IV or extragonadal primaries, second-look surgery was carried out, followed by four additional courses of chemotherapy with 100 mg/m2 VP-16 on days 1-3, 1.5 g/m2 ifosfamide on days 1-5 with mesna uroprotection and 20 mg/m2 cisplatin on days 1-5 with mannitol diuresis. In patients with sacrococcygeal germ-cell tumors, en bloc resection of the tumor, including the coccygeal bone, was mandatory. During the registration period, 57 patients with mNSGCTs were entered: 37 protocol patients and 20 follow-up patients. The event-free survival for protocol patients at 57 months was 78% +/- 6% and that for follow-up patients was 40% +/- 10% (Kaplan-Meier): the crude survival for both groups was 83% +/- 6% and 54% +/- 12%, respectively. After a review by a panel of pathologists, the histological diagnoses in 7% of all registered cases of germ-cell tumors were changed. The results of the present studies show that the histological subclassification of mNSGCTs, tumor site and tumor stage no longer had prognostic value.

Adolescent↗
PubMed1989

High-dose ifosfamide with mesna uroprotection in Ewing's sarcoma.

The German Society of Pediatric Oncology (GPO) has studied the efficacy of high-dose ifosfamide with mesna uroprotection in patients with Ewing's sarcoma. A phase II trial of ifosfamide (IFO) (2 g/m2 per day, days 1-5) in eight patients with recurrent evaluable disease resulted in three partial and two complete responses lasting from 3 to 12 months (median, 6 months). In a second phase II trial in 15 patients, the combination of IFO and cisplatin (20 mg/m2 per day, days 1-5) resulted in 7 partial and 2 complete responses lasting from 3 to 32 months (median, 6 months). Consequently, in 1985 IFO was incorporated into first-line chemotherapy for newly diagnosed patients (replacing cyclophosphamide) and given in combination with vincristine, actinomycin D, and adriamycin (VAIA) in patients considered to be at high risk for relapse. IFO was given at a dose of 3 g/m per day on days 1 and 2 as a 48-h continuous infusion, in combination with actinomycin D (0.5 mg/m2 per day on days 1-3) or Adriamycin (30 mg/m2 per day on days 1 and 2). The study was piloted from March to December 1985 and has been open since January 1986; 37 patients were entered during the pilot phase and 65 have been entered in the ongoing main trial since January 1986. At present, Kaplan-Meier disease-free survival projects that disease-free survival in patients with large primary tumors has improved compared with that reported for the previous CESS 81 trial. The toxicity of the VAIA regimen was comparable with that of the conventional vincristine, actinomycin D, cyclophosphamide, and adriamycin (VACA) regime used in the previous CESS 81 trial.

Actuarial Analysis↗
PubMed1989

Aseptic osteonecroses in the treatment of childhood acute leukaemias.

The incidence of aseptic osteonecroses in the therapy of acute leukaemias in children has been studied. Out of 551 children treated at the Children's Hospital in Münster from 1971 to 1985, 6 developed osteonecrosis, an incidence of 1.09%. Of these children, 5 showed unilateral or bilateral necrosis of the femoral head. The osteonecroses occurred 8-109 months after initiation of the primary therapy or of the relapse treatment. The corticoid doses did not differ from those administered to other leukaemia patients without necrosis. Only 1 patient had received prednisone continuously for 1 year, at a total dose of 20.5 g/m2 of body surface area. Of these 6 children, 4 had been immobilized for several weeks before or during therapy. Two children had presented with pain-related relieving posture of the joints in which subsequently the osteonecrosis developed. Inactivity associated with the cortisone therapy seems to be an important factor in the development of aseptic osteonecroses.

Adolescent↗
PubMed1989

[Iatrogenic foreign body of the nose].

The present case involves an intranasal foreign body that was discovered five months after conservative therapy of a myocardial infarction. In such cases, oxygen tubes are fixed by plastic blocks which can accidentally become lodged in the nose. In this case, an elderly patient was suspected of having a carcinoma of the inner nose.

Aged↗
PubMed1989

Musculoskeletal neoplasms: static and dynamic Gd-DTPA--enhanced MR imaging.

Static and dynamic magnetic resonance imaging studies were performed in 69 patients with bone and soft-tissue tumors. T1-weighted spin-echo (SE) imaging after intravenous administration of gadolinium diethylenetriaminepentaacetic acid (DTPA) improved the differentiation of necrotic from viable areas; the contrast-to-noise ratio (C/N) between tumor and muscle was an average of 44% lower compared with that in T2-weighted SE imaging. The C/N between tumor and bone marrow or fatty tissue was 43% and 37% lower, respectively, compared with that in nonenhanced T1-weighted SE imaging. Dynamic changes of signal intensity (SI) after Gd-DTPA enhancement were assessed with fast low-angle shot imaging. Of malignant tumors, 84.1% exhibited slopes higher than 30% per minute; 72% of benign tumors showed slopes lower than 30% per minute. The dynamic technique enabled assessment of the malignant potential of a tumor with some overlap (accuracy, 79.7%). Necrotic areas and peritumorous edema showed significantly lower and more gradual increases in SI than adjacent neoplastic tissue.

Adipose Tissue↗
PubMed1989

Acute myeloid leukemia: analysis of ras gene mutations and clonality defined by polymorphic X-linked loci.

In vitro DNA amplification and synthetic oligonucleotide hybridization was used to analyze 57 acute myelocytic leukemias (AML) for the presence of ras gene mutations. We demonstrated mutated alleles in 19% of primary AMLs (10/51) as well as in five of six secondary leukemias. Mutations occurred predominantly at N-ras codons 12, 13, or 61 (13 cases) and twice at Ki-ras codons 12 and 13. Ras gene mutations were preferentially associated with an M4 morphology according to the FAB (French-American-British) classification, but no particular correlation was observed with respect to clinical parameter (sex, age, course of disease) or immunophenotype and karyotype. Mutated ras alleles were absent in nine mutation-positive cases analyzed during remission. However, a more complex pattern emerged from the five patients analyzed in relapse exhibiting identical ras mutations in three cases, absence of a mutated allele in one patient, and acquisition of a N-ras mutation in yet another case, in which no mutation had been detected initially. Moreover, restriction fragment length polymorphisms (RFLP) of the X-chromosome genes hypoxanthine phosphoribosyl transferase (HPRT) and phosphoglycerate kinase (PGK) were studied in 19 of the AML patients. Nine cases (47%) were heterozygous for BglI or BamHI RFLPs at the PGK or HPRT loci, respectively, and therefore suitable for clonal analysis investigating X-chromosome inactivation. All of the patients exhibited a monoclonal leukemic cell population at presentation. In addition, five of seven cases studied in remission showed reemergence of a polyclonal pattern. However, two children exhibited persistence of monoclonal hematopoiesis despite complete clinical/hematological remission and a corresponding loss of a mutated ras allele in one of the patients. These data indicate the value of molecular genetic approaches for evaluation of the heterogeneous nature of remission and relapse in AML.

Adolescent↗
PubMed1989

[Acyclovir and pregnancy: current aspects].

Acyclovir (ACV), an antiviral nucleoside analog, is active against Herpes simplex viruses (HSV1, HSV2) and varicella virus (VZV). These viruses seems to be prejudicial to the pregnant woman and to the fetus. Yet, ACV is not recommended for use in pregnancy. However in certain cases, this drug has been used. We review in this paper, the pharmacokinetics and transplacental passage of ACV, indications, and whether the benefits of the administration of ACV in pregnancy outweigh the theoretical risks. Peak and trough plasma concentrations of ACV in pregnant women seem to be lower as compared to those of non-pregnant adults but effective. This drug crosses the placenta. Levels of ACV in cord blood ranged from 0.5 to 3 mumol/l. In as much as in vitro inhibitory doses 50 (ID 50) for HSV1, HSV2 and VZV ranged from 0.1 to 3 mumol/l, it is quite likely that levels noted above may be effective for in utero inhibition of viral replication. No adverse effects were noted in newborn exposed in utero to ACV. But one must be careful about the direct effects of this drug on nucleic acid metabolism despite encouraging results on animal fetuses. Based on these findings and from our experience, ACV can be administered in pregnancy in two particular situations: in cases of maternal severe viral infections and in order to inhibit in utero VZV replication. Doses required for pregnant women range from 5 to 15 mg/kg/8 hours given intravenously, and 200 mg of oral Acyclovir 5 times daily.

Acyclovir↗
PubMed1989

[The adhesive strength of tissue adhesives].

Twenty concentrates were produced of the blood from voluntary healthy donors by a method for producing autologous tissue adhesive. Their adhesive strength were tested by means of Thermo-fleece-specimens. A review was elaborated about the kinetics and the testing of the fibrin fixation. Methodical faults were found out. Possible ways for improving autologous adhesive variants and for producing homologue tissue adhesive are shown.

Adhesiveness↗
PubMed1989

Phenotypic and genotypic heterogeneity in infant acute leukemia. I. Acute lymphoblastic leukemia.

We have studied the immunophenotypic and genotypic features in 35 infants aged less than 1 year with acute lymphoblastic leukemia (ALL) or acute undifferentiated leukemia (AUL). A CD10 (common ALL antigen)-negative, CD19-positive pre-pre-B ALL phenotype was observed in 24 infants. Seventeen of them had blast cells coexpressing myeloid-associated markers such as CD15A (VIM-D5, MZ17) and/or VIM-2, but neither myeloperoxidase nor platelet peroxidase was detected in five of these cases analyzed by electron microscopy. Five patients showed a typical common ALL, five a pre-B ALL phenotype, and one infant was unclassifiable by surface-marker and morphologic analysis. Cytogenetic data, available in 21 of these patients, revealed chromosomal abnormalities involving 11q23 in 10 infants with a CD10-negative pre-pre-B ALL. Immunoglobulin (Ig) and T cell receptor (TCR) gamma, beta and delta gene analysis of 31 infants showed Ig heavy-chain gene rearrangement in all but one patient with evidence for clonal evolution in six and kappa-light-chain rearrangement in three infants. TCR beta-chain and TCR gamma-chain rearrangement occurred in six and five patients respectively, while TCR delta-chain rearrangement was identified in 15 patients. Our data indicate that ALL in infancy may present with heterogeneous immunophenotypic and genotypic features. The high frequency of coexpression of B-lineage and myeloid surface markers as well as of chromosomal rearrangement involving 11q23 suggests that the clonogenic cell of infant ALL may relate to a multipotent progenitor cell in most cases.

Antibodies, Monoclonal↗
PubMed1989

Phenotypic and genotypic heterogeneity in infant acute leukemia. II. Acute nonlymphoblastic leukemia.

We have studied the immunophenotypic and genotypic characteristic of acute nonlymphoblastic leukemias (ANLL) in infants aged less than one year. Sixty-four percent of cases (16/25) showed a myeloid or myelomonocytic differentiation pattern and 10 of these were classified as FAB M5 (7 M5a, 3 M5b). Only seven of the latter cases expressed the CD14 antigen. Acute megakaryocytic leukemia with a high number of glycoprotein IIb/IIIa or IIIa positive blasts were identified in five patients. Erythroleukemia with a high percentage of rather mature glycophorin A positive erythroblasts were diagnosed in two infants. Cytogenetic studies were successfully performed in all 20 cases investigated. Abnormalities involving chromosome 11 were present in 10 of 17 patients with an abnormal karyotype including five cases with a t(9;11)(p21;q23). Immunoglobulin (Ig) and T cell receptor (TCR) gene analyses were performed in 20 patients. A rearrangement of Ig heavy chain sequences was detected in five cases (20%), one of whom exhibited multiple rearranged fragments. Three of these patients showed additional TCR delta-chain gene rearrangements, while Ig kappa, TCR beta- as well as TCR gamma-chain genes showed a germline configuration in all cases analyzed. Our study confirms the high incidence of myelomonocytic and monoblastic subtypes in infants with ANLL, which are particularly closely associated with chromosome 11 abnormalities. However, we also observed an unexpected high frequency of megakaryoblastic leukemias as well as erythroleukemias. As previously reported for ALL in infants, ANLL of infancy shows a similar heterogeneity regarding phenotypic and genotypic features.

Antigens, Differentiation↗
PubMed1988

Prognostic significance of chromosome analysis in de novo acute myeloid leukemia (AML).

Between 1981 and 1986 cytogenetic studies of bone marrow and/or blood cells in 139 patients with de novo acute myeloid leukemia (AML) were performed. The overall incidence of chromosomal aberrations was 53%, and this was not significantly influenced by sex, age nor the FAB classification. The aberrations most often found were: complex anomalies (n = 13), t(8; 21) (n = 10), trisomy 8 (n = 9), monosomy 7 (n = 6), monosomy 5, 5q-, trisomy 11, 12p- (n = 4) and trisomy 6, 11q-, inv (n = 3). The prognostic significance of chromosomal findings was evaluated in 112 patients treated by combination chemotherapy. The chromosomal status NN, AN, AA did neither significantly influence complete remission rate (NN: 68%, AN: 71%, AA: 60%) nor mean survival (NN: 24, AN: 26.6, AA: 35.6 months). On the other hand, certain types of chromosomal anomalies were of prognostic value. CR was obtained in all 10 patients with t(8; 21) but only in 2 out of 9 patients with complex aberrations. Median duration of CR in patients with t(8; 21) was significantly longer than in patients with a normal karyotype (30 vs 7 months).

Adolescent↗
PubMed1988

Neoadjuvant chemotherapy of osteosarcoma: results of a randomized cooperative trial (COSS-82) with salvage chemotherapy based on histological tumor response.

Following observation of the predictive value of the histologic extent of tumor cell destruction after preoperative chemotherapy for metastasis-free survival (MFS) in osteosarcoma, a randomized study was undertaken with the aim of (1) sparing some patients the unpleasant side effects of highly toxic drugs like doxorubicin (DOX) and cisplatin (CPDD) by administering these drugs postoperatively only after poor response with a milder preoperative regimen, and (2) improving the prognosis of patients responding poorly to the initial treatment by use of a salvage chemotherapy postoperatively. The available patients were divided into two groups. Those in the study arm received a preoperative chemotherapy consisting of high-dose methotrexate (HDMTX) and the triple drug combination of bleomycin, cyclophosphamide, and dactinomycin (BCD) and were switched to DOX/CPDD postoperatively in case of poor response. DOX/CPDD was used besides HDMTX for initial treatment in the control arm, and BCD alternatively with CPDD/ifosfamide (IFO) for postoperative salvage treatment. The response rate of the study arm was significantly inferior to the control arm (26% v 60%; P less than .001). The actuarial 4-year MFS rate of poor responders after salvage chemotherapy also was poorest in the study arm (41%); it was unchanged in the control arm (53%) as compared with that of poor responders from the COSS-80 study without salvage chemotherapy (52%). The actuarial 4-year MFS rate of good responders was 73% in the study arm, 79% in the control arm, and not significantly different from that of the COSS-80 study (84%), although postoperative chemotherapy of good responders had been markedly shortened as compared with the COSS-80 study. The actuarial 4-year MFS rate of the study arm as a whole was inferior to that of the control arm (49% v 68%; P less than .1) and also inferior to the COSS-80 study (68%; P less than .01), indicating a failure of the employed salvage strategy in general and especially of the effort to restrict the use of the very effective but highly toxic drugs DOX and CPDD to patients resistant to a less toxic initial treatment.

Actuarial Analysis↗
PubMed1988

Ambiguous phenotypes and genotypes in 16 children with acute leukemia as characterized by multiparameter analysis.

Ambiguous phenotypes and genotypes were observed in 16 children with acute leukemia. Surface marker, cytogenetic, molecular genetic, and DNA flow cytometric analyses as well as standard morphologic and cytochemical studies were used to divide the patients into three groups. The first group comprised five children with acute leukemia whose blast cells were morphologically lymphoid, while immunophenotyping disclosed simultaneous expression of early pre-B cell and myeloid features. Molecular genetic studies showed evidence of heavy-chain immunoglobulin (Ig) gene rearrangements in all patients. Cytogenetic data, available in three of these children, revealed t(4;11). In five of the 16 patients, morphologic and surface marker analyses indicated the coexistence of two separate cell populations, one with myeloid and the other with early pre-B cell features. Further evidence of B cell commitment in these patients was provided by demonstration of Ig heavy-chain gene rearrangements in all five patients. Surprisingly, one of the five patients showed oligoclonal Ig heavy-chain as well as monoclonal gene rearrangement for the beta chain of the T cell receptor (beta-TCR). The last group consisted of four cases with otherwise typical acute lymphoblastic leukemia (ALL), early pre-B cell phenotype, and coexpression of myeloid or T cell-associated antigens, and two children with unequivocal acute myeloid leukemia (AML) and coexpression of T cell antigens. Gene rearrangement of Ig heavy-chain could be demonstrated in five of six patients, additional Ig light-chain gene rearrangement in two children with ALL, and bigenotypic features (Ig heavy-chain and beta-TCR gene rearrangement) in one patient. In none of the 16 patients did flow cytometry disclose clonal abnormalities of leukemic cell DNA content. Based on these findings, we suggest that malignant transformation in the first and second group of patients took place at a stage ontogenetically close to the pluripotent stem cell, whereas ambiguous phenotypes in the third group resulted from aberrant gene expression or insufficient reagent specificity.

Acute Disease↗
PubMed1987

Early deaths due to hemorrhage and leukostasis in childhood acute myelogenous leukemia. Associations with hyperleukocytosis and acute monocytic leukemia.

There were 294 children with acute myelogenous leukemia (AML) entered into the German AML Berlin, Frankfurt, and Münster hospitals (BFM) 78 and 83 studies. Thirty (10%) died as a result of hemorrhage and/or leukostasis prior to or in the first 12 days of therapy. The risk of early death due to hemorrhage and/or leukostasis is significantly greater when certain features are initially present: acute monocytic leukemia (French-American-British [FAB] M5), hyperleukocytosis (greater than or equal to 100,000/microliter), and extramedullary organ involvement (P less than 0.001). The risk increases sharply when these factors exist in combination: 72% mortality with FAB M5 and hyperleukocytosis, and 43% with FAB M5 and extramedullary organ involvement. In 11 patients leukostasis alone or in combination with hemorrhage was probably the cause of death during the first 3 days after diagnosis. All 11 children presented with hyperleukocytosis and were classified as monocytic subtype FAB M4 or M5. After induction, a close temporal association between rapid blast reduction and occurrence of fatal hemorrhage was established in five patients. Thrombocytopenic hemorrhages were controllable and, therefore, responsible for death only in exceptional cases. It is difficult to avoid these early fatal complications with current therapeutic measures. Early exchange transfusion together with special supportive care may be useful.

Adolescent↗
PubMed1987

Treatment of neuroblastoma with 131I-metaiodobenzylguanidine: experience of the Münster/Kassel Group.

I-131-metaiodobenzylguanidine was used for treatment of neuroblastoma stage IV in three children after surgery and or chemotherapy had failed to be effective. In two of the children with multilocular lesions, after an impressive improvement of clinical symptoms tumor progression was observed. Because in about 25% of children with relapsing neuroblastoma complete remission may be achieved by combining surgery, chemotherapy, and I-131-MIBG treatment, this therapeutic modality should be included in the therapeutic strategy of stage III and IV neuroblastoma.

3-Iodobenzylguanidine↗