Biomedical subjects

R Erttmann

Publications and source records attributed to R Erttmann.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Pharmacokinetics of the 5HT3 receptor antagonist tropisetron in children.

A pharmacokinetic study in children was performed to assess whether the pharmacokinetic profile of tropisetron in pediatric patients in similar to that in adults. In three pediatric centers, three dosages were tested in two age groups during chemotherapy (Group A, 3-6 years, 2, 5, or 20 mg/m2; group B, 7-15 years, 2, 5, or 20 mg). Children received tropisetron intravenously (course 1) or orally (course 2) before the start of chemotherapy. Blood samples were drawn over 24 hours. Tropisetron treatment continued for up to 6 days at the same daily dose, administered orally. Data were available for 45 patients after intravenous and for 38 patients after oral administration. 82% of course 1 patients and 72% of course 2 patients had no emesis on day 1. Headache occurred in eight patients and abdominal symptoms in three patients. Terminal half-life (5.3-6.6 hours), tmax (1.4-1.5 hours), and absolute bioavailability (41-42%) were identical in both age groups and comparable to those in adults. Because of a smaller volume of distribution, group A children showed a higher Cmax/dose (P < .001) and a higher area under curve (AUC) dose (P < .05) than adults. All parameters were independent of the dose administered. In conclusion, the elimination and absolute bioavailability of tropisetron in children are similar to those in adults. Because of its age-dependent volume of distribution, tropisetron should be administered once a day according to the body surface area in children below 10 years of age.

Administration, Oral↗

PubMedDate not supplied

Naturally occurring humoral cytotoxicity against neuroblastoma (NB) cells in healthy persons and NB patients.

A novel cytotoxic mechanism against neuroblastoma (NB) cells based on natural immunoglobulin M serum antibodies is described. The occurrence of these antibodies, which are able to induce complement-mediated cytolysis of NB cells, has been investigated in several age groups of healthy persons and in patients with NB. The cytotoxicity of serum samples has been measured in terms of propidium iodide DNA incorporation using a FACScan. The prevalence of anti-NB 1gM antibodies shows a strong age dependence characterized by a nearly complete lack in the first year of life and a steep rise up to 82% beginning with the second year of life. In the sera of 11 NB-bearing patients no cytotoxicity has been found, despite the fact that 8 of these patients were older than 1 year. These findings lead to the hypothesis that natural 1gM antibodies could play a role as an immunological control mechanism against NB.

Antibodies, Neoplasm↗

PubMedDate not supplied

Early toxicity of intensified conditioning with etoposide combined with total body irradiation/cyclophosphamide or busulfan/cyclophosphamide in children undergoing autologous or allogeneic bone marrow transplantation.

In recent years, high dose chemotherapy followed by bone marrow rescue has been established as a common treatment of hematologic and solid tumor malignancies. Despite unequivocal success, relapse after transplant remains a serious problem, being the main cause of treatment failure. In an attempt to reduce relapse rates, we intensified the conditioning regimens consisting of busulfan/cyclophosphamide versus fractionated total body irradiation (f-TBI)/ cyclophosphamide by the addition of high dose etoposide. Toxicity profiles of 25 pediatric patients with hematologic malignancies undergoing intensified conditioning did not differ significantly between the two groups, except for a higher incidence of veno-occlusive disease in busulfan-treated patients (3 of 13 patients) compared with the TBI group (0 of 12 patients). We observed no transplant-related mortality in neither group. Regimen-associated morbidity was moderate and reversible in all cases. Five patients died in each treatment arm, due to relapse of the underlying disease. We conclude that both regimens are feasible in marrow transplantation of pediatric patients. Open randomized trials are needed to assess the efficacy of intensified conditioning in terms of disease-free survival.

Adolescent↗

PubMedDate not supplied

[Results of the HB-89 Study in treatment of malignant epithelial liver tumors in childhood and concept of a new HB-94 protocol].

94 children with a primary liver neoplasm were registered in the Cooperative Pediatric Liver Tumor Study HB-89 of the GPOH from 1988 to 1992. 64 of these had a hepatoblastoma (HB), 12 a hepatocellular carcinoma (HCC), 2 a sarcoma and 16 a benign tumor. 51 (80%) patients with an HB were 6 to 36 months of age, 9 with an HCC above 10 years. Initial serum-alpha-fetoprotein (AFP) was elevated in 51 HB patients and exceeded the 3-fold of normal range in 45. Children with low (< 100 ng/ml) and very high (> 1,000,000 ng/ml) levels had a significantly worse prognosis than those with intermediate values (p = 0.0014). AFP was moderately elevated in 9 HCC patients. All other tumor markers were only irregularly above normal range. 48 (77%) of HB patients survived, 45 (73%) are tumor free. All of 18 stage I and 4/5 stage II patients are in remission. After chemotherapy 30/36 stage III HBs and 2/5 stage IV HBs could be resected, 9 of these patients suffered from tumor relapse. Disease-free survival was 100% for stage I, 80% for stage II, 68% for stage III and zero for stage IV HB (p = 0.0005). Surgical complications occurred after 8% of biopsies, 13% of limited primary resections and 25% of extended secondary resections. There was no perioperative death. The completeness of tumor resection at primary or delayed surgery correlated significantly with patients disease-free survival (p < 0.0001). Chemotherapy with ifosfamide, cisplatin and adriamycin was effective in HB. 203 courses were given in 61 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗

PubMedDate not supplied

Structurally modified anthracyclines retain activity in a cell line with simultaneous typical and atypical multidrug resistance.

Resistance to the classical anthracyclines may be due to one or several mechanisms, most notably p-glycoprotein (pGP) associated multidrug resistance (mdr1, "typical mdr") and altered activity of topoisomerase II (topo II) ("atypical mdr"). Modulators of mdr1 will be of limited value in case of combined forms of resistance. A Friend murine erythroleukemia cell line (F4-6R) carrying both mdrl and topo II mediated anthracycline resistance was used to determine the efficacy of structurally altered anthracyclines against such extended multidrug resistance. Proliferation assays showed that 3'N-morpholinyl substituted anthracyclines were able to retain much of their activity even in this setting. MX2 (KRN8602; 3'-deamino-3'-[4-morpholinyl]-13-deoxo-10-hydroxycarminomycin+ ++), which is 9-alkylated in addition to carrying a 3'N-morpholinyl group, was the most promising agent tested.

Animals↗

PubMedDate not supplied

Factors influencing the haematological recovery after allogeneic bone marrow transplantation in leukaemia patients treated with methotrexate-containing GVHD prophylaxis: a single-centre experience.

In the present single institution study of 66 leukaemia patients (28 AML, 23 ALL, 15 CML), the factors influencing haematological recovery after allogeneic bone marrow transplantation (alloBMT) were analysed retrospectively in order to identify the optimal conditions required for a rapid haematological recovery after alloBMT. All patients received GVHD prophylaxis with cyclosporine A plus methotrexate. The mean number of days required to achieve > or = 0.5 x 109/l neutrophil count after alloBMT was 17 (median 17, range 9 to 27 days) and 19 patients (28.8%) had rapid neutrophil recovery within 15 days after alloBMT. The haematological recovery was more rapid in the 38 patients without GVHD or with only grade I GVHD. Furthermore, 50% and 40% of patients receiving 10 (n = 18) or 5 (n = 20) micrograms/kg/day G-CSF had rapid neutrophil recovery within 15 days after alloBMT, versus only 7.1% of patients not receiving G-CSF post-transplant (n = 28), p < 0.001. The neutrophil recovery was similar in patients receiving either fresh or cryopreserved allografts and either TBI-containing or busulfan-containing conditioning regimen. A significant correlation was found between neutrophil recovery and either the MNC or CFU-GM content of the allografts, r = 0.33, p < 0.01. The mean number of days required for neutrophil recovery was only 16 days (median 16, range 9 to 24 days) in patients receiving allografts containing > 1 x 10(5) CFU-GM/kg (n = 28) versus 19 days (median 19, range 13 to 27 days) in patients receiving allografts containing < 1 x 10(5) CFU-GM/kg (n = 35). Three patients receiving allografts containing less than 0.5 x 10(5) CFU-GM/kg had primary neutrophil engraftment failure. The mean number of days required to achieve 20 x 109/l platelet count was 21 (median 20, range 11 to 50 days) and 30 patients (46.9%) had platelet recovery within 20 days after alloBMT. The platelet recovery after alloBMT was not significantly affected by the type of leukaemia, conditioning regimen, or G-CSF administration. The mean number of days required for platelet recovery after alloBMT was only 20 days (median 18 days) in patients receiving allografts containing > 1.0 x 10(5) BFU-E/kg (n = 35) versus 23 days (median 20 days) in patients receiving allografts containing < 1.0 x 10(5) BFU-E/kg (n = 24). Seven patients receiving allografts containing less than 0.5 x 10(5) BFU-E/kg had primary platelet engraftment failure. The present study has identified the high number of progenitor cells in the allografts infused and the daily administration of G-CSF post-transplant as the optimal combination for a rapid neutrophil recovery after alloBMT. More significantly, the number of BFU-E in allografts was the most significant factor to determine platelet recovery after alloBMT. The development of GVHD of grade II or more during the first weeks after alloBMT was associated with slower haematological recovery and longer period of fever during neutropenia and hospitalisation.

Acute Disease↗