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Biomedical subjects

M Stockschläder

Publications and source records attributed to M Stockschläder.

At least 55 records · Page 3Linked to original sources
PubMed1996

Improved retroviral vectors for hematopoietic stem cell protection and in vivo selection.

Therapeutic gene transfer into hematopoietic cells is critically dependent on the evolution of methods that allow ex vivo expansion, high-frequency transduction, and selection of gene-modified long-term repopulating cells. Progress in this area needs elaboration of defined culture and transduction conditions for long-term repopulating cells and improvement of gene transfer systems. We have optimized retroviral vector constructions based on murine leukemia viruses (MuLV) to overcome the transcriptional repression encountered with the use of conventional Moloney MuLV (MoMuLV) vectors in early hematopoietic progenitor cells (HPC). Novel retroviral vectors, termed FMEV (for Friend-MCF/MESV hybrid vectors), were cloned that mediate greatly improved gene expression in the myeloerythroid compartment. Transfer of the selectable marker multidrug resistance 1 (mdr1), FMEV, in contrast to conventional MoMuLV-related vectors currently in use for clinical protocols, mediated background-free selectability of transduced human HPC in the presence of myeloablative doses of the cytostatic agent paclitaxel in vitro. Furthermore, FMEV also greatly improved chemo-protection of hematopoietic progenitor cells in a murine model system in vivo. Finally, when a second gene was transferred along with mdr1 in an FMEV-backbone, close to 100% coexpression was observed in multidrug-resistant colonies. These observations have significant consequences for a number of ongoing and planned gene therapy trials, for example, stem cell protection to reduce the myelotoxic side effects of anticancer chemotherapy, correction of inherited disorders involving hematopoietic cells, and antagonism of HIV infection.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Fatal outcome of disseminated candidosis after allogeneic bone marrow transplantation under treatment with liposomal and conventional amphotericin-B. A report of 4 cases with determination of the Mic values.

Four patients undergoing allogeneic bone marrow transplantation were treated with liposomal (3 patients) and conventional (one patient) amphotericin-B for disseminated candidosis. Candida krusei was isolated from 3, and C. glabrata from 1 patient. The patients were treated with liposomal amphotericin-B in doses from 3 to 5 mg/kg. The fourth patient received conventional amphotericin-B in a reduced dose due to renal impairment. The patients died from multiorgan failure due to disseminated fungal infection. In 1 case, the switch to the conventional drug resulted in clearance before death. The 3 fungus isolates, together with the fourth strain obtained from patient no. 4 without any exposition to liposomal amphotericin-B were tested for their susceptibility to conventional, liposomal and discoidal amphotericin-B. All strains showed good sensitivity to the conventional and discoidal drug. The minimal inhibitory concentrations (MIC) of liposomal amphotericin-B were 1 to 3 titre steps higher indicating a reduced sensitivity of the tested strains to this preparation. We conclude that the use of liposomal amphotericin-B is recommended mainly on the base of the low incidence of side-effects. Intensive microbial resistance tests, pharmacokinetic investigations and randomized studies are necessary before the conventional drug is replaced as the gold standard for systemic antimycotic therapy.

Adult↗
PubMed1996

Use of cryopreserved bone marrow in unrelated allogeneic transplantation.

Cryopreservation of donor bone marrow can facilitate scheduling allogeneic bone marrow transplantation (BMT) by affording independence of a preset time for donation. Previously, we and others have shown the feasibility of using cryopreserved related allogeneic bone marrow. Here, we report the results of the first 10 patients receiving cryopreserved unrelated bone marrow between 1992 and 1995. All evaluable patients (n = 9) engrafted. Time to reach an absolute neutrophil count (ANC) >0.2 x 10(9)/1 and ANC >0.5 x 10(9)/l was 21.4 +/- 9.1 days and 22.6 +/- 9.2 days, respectively. The incidence of acute GVHD > or = grade II and chronic GVHD was 75 and 20%, respectively. Five of nine evaluable patients were alive 100 days post-transplantation. We conclude that cryopreserved unrelated donor bone marrow may be used for allogeneic transplantation.

Adolescent↗
PubMed1996

Increase of mobilized CD34-positive peripheral blood progenitor cells in patients with Hodgkin's disease, non-Hodgkin's lymphoma, and cancer of the testis.

G-CSF (filgrastim) can effectively mobilize peripheral blood progenitor cells (PBPC) when administered during steady-state hematopoiesis. In this single center study, we compared the effectiveness of two different doses of G-CSF on the mobilization of peripheral blood stem cells in patients with Hodgkin's disease, non-Hodgkin's lymphoma, and cancer of the testis. A first group including 33 patients received 10 micrograms G-CSF/kg BW per day (group A), whereas a second group comprising 34 patients was treated with 24 (2 x 12) micrograms G-CSF/kg body weight (BW) per day (group B) prior to the leukapheresis. A significant difference (P = 0.015) in the total number of CD34+ cells between group A: 11.32 x 10(7) (range 0.34-110.2) and group B: 48.25 x 10(7) (range 1.33-447.4) has been observed in the first leukapheresis product. Moreover, the total number of CFU-GM increased significantly from 34.79 x 10(4) (range 1.07-300.9) to 147.69 x 10(4) (range 1.03- 1204.0) (P < 0.005), and the number of MNC increased from 1.35 x 10(10) (range 0.41-3.09) group A) to 2.93 x 10(10) (range 0.66-9.7) (group B) (P < 0.001). Comparable results were obtained in the second leukapheresis. Our data indicate, that the application of higher doses of G-CSF can significantly improve the effectiveness of mobilizing PBPC during steady-state conditions, and thereby considerably contribute to a safe and fast engraftment as well as a reduced number of leukapheresis procedures to achieve sufficient number of PBPC.

Adolescent↗
PubMed1996

Serum interleukin-6 levels during bone marrow transplantation: impact on transplant-related toxicity and engraftment.

The biological properties of IL-6 include the induction of acute phase proteins, stimulation of hematopoietic stem cell growth and thrombopoiesis. Serum levels of IL-6 were closely monitored in 66 patients before and after allogeneic (n = 37), autologous bone marrow transplantation (n = 8) or autologous peripheral blood stem cell transplantation (n = 21). Almost every patient showed elevated IL-6 serum levels during the aplastic phase. Patients then suffered from mucositis, had elevated C-reactive protein (CRP) and usually body temperatures of above 38 degrees C. It was investigated whether IL-6 serum levels, apart from inducing acute phase reactions, correlated with transplant-related complications or leukocyte and thrombocyte engraftment. By statistical analysis, a correlation was found between IL-6 and CRP and between IL-6 and fever. In contrast, no correlation was found between IL-6 and elevated serum bilirubin as a marker for hepatotoxicity. IL-6 showed a weak negative correlation with leukocyte or platelet counts. In contrast, the day of platelet engraftment correlated with the day of peak serum IL-6 value, possibly indicating an influence of IL-6 on platelet engraftment.

Bilirubin↗
PubMed1996

Detection of cancer cells in peripheral blood stem cells of women with breast cancer by RT-PCR and cell culture.

The benefit of high-dose therapy and blood stem cell reinfusion for women with high-risk breast cancer is currently under investigation. Contaminations of autologous blood stem cells with cancer cells have been described. Cancer micrometastases may be detected by immunocytochemistry, culture techniques and cytokeratin-19 mRNA reverse transcriptase PCR. Women with breast cancer received adjuvant HD-CTM with peripheral blood stem cell (PBSC) support after surgical therapy and 4 cycles conventional chemotherapy. Peripheral blood stem cells were mobilised by G-CsF and harvested after the third or fourth cycle of standard therapy. Aliquots of PBSC-collections (10(7)-2*10(7) cells) were subjected to CK19-mRNA reverse transcriptase PCR. RNA was extracted by standard methods and reverse transcription was performed with MMV-RT. Integrity of RNA was checked by coamplification of housekeeping sequences. Aliquots of the RT-mix were subjected to PCR-amplification with outer and inner primer pairs, subsequently. A second aliquot of 2*10(7) cells was cultured over 42 days in liquid culture. Cytospins were prepared weekly from cultured cells and evaluated by light microscopy with or without prior immunocytochemistry. Ten leukaphereses from 6 women were available for PCR-analysis and cell culture. Six leukaphereses were negative for CK19-mRNA and for detection of cancer cells by culture technique, two samples were positive for CK19-mRNA and culturally enriched cells and two samples were positive for CK19-mRNA and negative for cultured cancer cells. No sample was positive for cultured cells and negative for CK19-mRNA. Overall, the results corresponded in 80%. Two sensitive techniques for the detection of cancer micrometastases were applied to aliquots from 10 leukaphereses of six breast cancer patients with corresponding results in 80%. PCR-mediated detection of cancer cells was confirmed by culture technique and light microscopy, however, further comparison of CK19-PCR with standard techniques like cell culture and immunocytochemistry is still necessary.

Breast Neoplasms↗
PubMed1995

Cyclophosphamide/antithymocyte globulin conditioning of patients with severe aplastic anemia for marrow transplantation from HLA-matched siblings: preliminary results.

Many approaches have been taken to reducing the rate of graft failure and the incidence of graft-versus-host disease (GVHD) in bone marrow transplantation (BMT) of patients with severe aplastic anemia (SAA). The combination of cyclophosphamide with irradiation has had unequivocal success in reconstituting a sustained engraftment, but this procedure has severe associated risks such as second malignancies. Recently, cyclophosphamide (CYC) plus antithymocyte globulin (ATG) has been shown to be an effective alternative to irradiation-based programs in retransplants. Based on these experiences, the current clinical trial was started to prepare patients suffering from SAA for marrow transplantation from HLA-identical siblings with ATG plus CYC. Nine patients have been enrolled into the study so far. They received a total dose of 200 mg/kg CYC and concomitantly 120 mg/kg or 90 mg/kg ATG, followed by cyclosporine plus methotrexate as post-transplantation GVHD prophylaxis. Eight of nine patients survived without any transplant-associated complications; i.e., they had a documented stable engraftment without rejection and without acute or chronic GVHD. One patient died due to an Aspergillus sepsis prior to a definite engraftment. Although our data are preliminary because of the small number of patients enrolled and a follow-up of only 30 months, CYC plus ATG appears to be an effective preparative regimen for BMT in patients with SAA, resulting in a favorable outcome.

Adolescent↗
PubMed1995

Experience with liposomal Amphotericin-B in 60 patients undergoing high-dose therapy and bone marrow or peripheral blood stem cell transplantation.

60 patients undergoing bone marrow or stem cell transplantation were treated with liposomal Amphotericin-B for documented or suspected mycosis. 34 patients had a prior course of conventional Amphotericin-B with the following adverse effects: increasing creatinine above 1.4 mg/dl (n = 17), increasing creatinine below 1.5 mg/dl (n = 9), no response (n = 6), and clinical side-effects (n = 4). Liposomal Amphotericin-B failed in 6/7 patients with culture-proven mycosis who died from infection with Aspergillus (n = 2) and Candida (n = 4), respectively. One patient with Candida lambica sepsis was cured. No patient with clinically or serologically suspected or diagnosed infection died from mycosis. Liposomal Amphotericin-B was well tolerated in 57 patients, even after side-effects of the conventional formulation. Adverse effects occurred in three cases, requiring the withdrawal of the drug in one patient. Due to toxic side-effects of the high-dose therapy and transplant-related complications, it was difficult to evaluate the influence of liposomal Amphotericin-B on laboratory parameters. Eight patients showed a decrease of creatinine levels, which had increased above normal values under preceding therapy with conventional Amphotericin-B. Liposomal Amphotericin-B is well tolerated in patients undergoing high-dose therapy and bone marrow transplantation. The efficacy of liposomal Amphotericin-B needs to be investigated in randomized studies in comparison with conventional Amphotericin-B.

Adolescent↗
PubMed1995

Use of cryopreserved bone marrow in allogeneic bone marrow transplantation.

Use of cryopreserved donor bone marrow may facilitate scheduling of allogeneic bone marrow transplantation (BMT) by affording independence of a fixed time for bone marrow donation. The potential risk of damage to hematopoietic stem cells by cryopreservation resulting in delayed engraftment or graft failure has to be taken into account, however. To address these issues, the outcome of 19 matched related BMT (1992-94) performed with cryopreserved donor bone marrow was analyzed and compared with 19 related BMT (1990-93) receiving fresh donor bone marrow (control group). Time to engraftment of patients receiving cryopreserved bone marrow was not different from the control group (ANC > 0.2 x 10(9)/l 15.5 +/- 3.8 days vs 15.8 +/- 5.0 days; ANC > 0.5 x 10(9)/l 17.3 +/- 4.1 days vs 17.9 +/- 5.0 days, respectively). We did not find the previously described trend toward a lower incidence of acute GVHD in patients receiving cryopreserved bone marrow compared with patients receiving fresh bone marrow (acute GVHD > or = II 78 vs 64%). Furthermore, the two groups did not differ in the incidence of chronic GVHD (55 vs 38%) or day 100 survival (74 vs 68%). We conclude that in allogeneic BMT cryopreserved bone marrow cells can be safely used without jeopardising or prolonging time to engraftment.

Adolescent↗
PubMed1995

Infusion of tumor-contaminated bone marrow for autologous rescue after high-dose therapy leading to long-term remission in a patient with relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia.

We report a female patient with relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia remaining in long-term second remission after high-dose radiochemotherapy followed by autologous stem cell rescue with bone marrow showing evidence of residual disease. The Philadelphia chromosome and a positive signal for the BCR/ABL p185 translocation by the polymerase chain reaction were detected in the harvested marrow. After mafosfamide-purged marrow failed to engraft, her unpurged 'back-up' bone marrow was also infused. Control marrow examinations after recovery were repeatedly positive for the BCR/ABL translocation on PCR analysis turning negative 30 months after high-dose therapy. She remains in unsustained complete clinical remission for 48+ months showing no evidence of leukemia by cytological and cytogenetic analyses.

Adult↗
PubMed1995

Inhibition of CFU-C growth by VP-16 containing plasma samples obtained from patients after conditioning therapy for bone marrow transplantation.

The introduction of VP-16 into high-dose therapy regimens used for conditioning before BMT or PBSCT has resulted in higher remission rates and prolonged disease-free survival, even in high risk patients. VP-16 levels have been measured in plasma at the time of transplantation. The question is, is there a biological activity that corresponds with the risk of delayed engraftment or graft failure? We investigated the inhibitory effects of plasma samples obtained from patients under high-dose VP-16 therapy on the growth of human bone marrow progenitor cells. Bone marrow cells from healthy donors were exposed to the plasma samples and seeded into methylcellulose-culture (CFU-C-assay). We found a dose dependent CFU-C inhibition related to VP-16 plasma levels at the time of transplantation (k = 0.769, P < 0.01). There were signs of a correlation between CFU-C growth inhibition at the time of BMT and haematological recovery (k = 0.656, P < 0.05) between CFU-C inhibition and the time until leucocytes reached 0.2 x 10(9)/l. Patients with CFU-C growth inhibition at the time of BMT may show delayed engraftment of leucocytes and that there might be a correlation with VP-16 levels, but further investigation is necessary to determine the significance of the latter thesis and if VP-16 plasma levels could lead to failure of engraftment. We recommend a minimum time interval between VP-16 infusion and graft transplantation of 72 h.

Adolescent↗
PubMed1995

Increasing the yield of harvested bone marrow cells by raising room temperature during marrow collection.

The time it takes to harvest bone marrow before transplantation could be reduced significantly by increasing the temperature of the operating room by 8-10 degrees C, to about 28-30 degrees C. In healthy donors, the collected volume of marrow was increased from 22.45 to 36.31 mL/min; in patients who received chemotherapy previously, from 21.67 to 29.98 mL/min. The time to collect a volume of 1200 mL marrow could be reduced significantly, from 57.78 to 38.25 minutes in healthy donors and from 71.07 to 43.36 minutes in patients who received chemotherapy previously, without any loss of quality of the sampled marrow. Operation time and thereby time of anesthesia could be reduced significantly by heating the operating room to a temperature of 28-30 degrees C. Harvesting at higher room temperature did not result in any adverse side effects for the patients. The procedure to increase the body temperature could be simplified by using electric blankets and aluminum foils for wrapping to avoid heat emission.

Adolescent↗
PubMed1995

Bone marrow transplantation for Philadelphia-chromosome-positive acute lymphoblastic leukemia.

The outcome of 14 bone marrow transplants (BMT) (autologous 4; allogeneic 10) for Philadelphia-chromosome (Ph1) positive acute lymphoblastic leukemia (ALL) was analyzed. Preparative regimens consisted of etoposide (VP16) (30 or 45 mg/kg BW) (n = 14), cyclophosphamide (CY)(120 mg/kg BW) (n = 14), and total body irradiation (TBI)(12 Gy) (n = 13) or busulfan (Bu)(16 mg/kg) (n = 1). All patients receiving autologous marrow were in complete remission (CR) (three patients in 1.CR, one patient in 2.CR) at the time of BMT. For allogeneic BMT (nine related, one unrelated donor), seven patients were in first CR, two patients in first refractory relapse, and one patient in second relapse. With a median follow-up of 503 days (range 93-1522 days), eight out of 14 patients are alive in remission (six out of 10 patients receiving allogeneic, and two out of four patients receiving autologous BMT). Disease-free survival for all patients is 46%. Causes of death were relapse (n = 3) and transplant-related toxicity (n = 3). All patients tested for the bcr/abl rearrangement by reverse transcriptase-polymerase chain reaction (RT-PCR) were negative 4 weeks post-BMT. Two of the three patients who subsequently relapsed were repeatedly RT-PCR positive prior to relapse (test not done in the third). Considering the negligible cure rate of Ph1-positive ALL with conventional chemotherapy regimens, our data support the concept of early (> or = 1 CR) BMT (allogeneic > autologous (purged) following triple therapy with TBI, VP16, and CY.

Adult↗
PubMed1995

Transplantation of allogeneic rhG-CSF mobilized peripheral CD34+ cells from an HLA-identical unrelated donor.

We describe the case of a 41-year-old female who underwent allogeneic blood cell transplantation with CD34(+)-enriched cells from an HLA-matched unrelated donor for AML in second CR. The conditioning regimen consisted of TBI (12 Gy), VP16 (1800 mg), cyclophosphamide (7200 mg), and ATG (7200 mg). GVHD prophylaxis consisted of CsA and a short course of MTX. Receiving G-CSF from day +1, engraftment occurred on day +19 after stem cell infusion. Starting on day +10, GVHD grade II (skin and liver) developed that responded to high-dose steroid therapy. The patient died on day +38 due to suspected cerebral aspergillus infection. This case demonstrates the feasibility of primary transplantation of CD34(+)-enriched allogeneic peripheral stem cells from a matched unrelated donor leading to engraftment of donor cells.

Adult↗
PubMed1994

Pharmacokinetics of undiluted or diluted high-dose etoposide with or without busulfan administered to patients with hematologic malignancies.

PURPOSE: We used two different methods to administer high-dose etoposide (VP-16) during a myeloablative conditioning chemotherapy regimen before bone marrow transplantation (BMT). VP-16 was administered either diluted (0.5 mg/mL) or undiluted (20 mg/mL), with or without busulfan. PATIENTS AND METHODS: Blood samples were drawn from 17 patients during the infusion (6 hours) and thereafter daily until 2 days after BMT. VP-16 concentrations were measured in all plasma samples by high-performance liquid chromatography (HPLC) and electrochemical detection, and the results were analyzed with a pharmacokinetic data analysis system. RESULTS: All calculated pharmacokinetic parameters in the two patient groups (VP-16 administered diluted or undiluted) were similar. There were no statistically significant differences in half-lives, mean residence time (MRT), volume of distribution, total clearance, or area under the curve (AUC). VP-16 was found in blood samples from eight of 17 patients at the time of BMT. Significant differences in systemic drug exposure and systemic clearance were found when patients were grouped according to treatment with busulfan or with total-body irradiation (TBI). CONCLUSION: The two administration modes for VP-16, either diluted or undiluted, are bioequivalent in pharmacokinetic terms. The terminal half-lives were longer than expected and resulted in significant VP-16 plasma levels at the time of BMT. The biologic significance remains unclear. Busulfan and/or concomitant medication with phenytoin influence plasma clearance (clp) and systemic drug exposure significantly.

Adolescent↗
PubMed1994

Pharmacokinetics of high-dose VP-16: 6-hour infusion versus 34-hour infusion.

VP-16 was administered in high doses (30-45 mg/kg) in combination with busulfan (BU) and cyclophosphamide (CY). The anticancer activity of VP-16 is thought to be schedule-dependent. We investigated a 6-h and a 34-h infusion of VP-16 to compare pharmacokinetic parameters and toxicity. Blood samples were taken from a total of 16 patients during infusion time (6 h and 34 h, respectively) and thereafter up to 2 days after bone marrow transplantation (BMT). VP-16 concentrations were measured in all plasma samples with HPLC technique and electrochemical detection and the results were analyzed with a pharmacokinetic data analysis system. All calculated pharmacokinetic parameters in the two patient groups were essentially similar. There were no statistically significant differences in half-lives, mean residence time, volume of distribution, total clearance and area under the curve. The treatment-related toxicity was not different between groups. The major difference was the maximal concentration in the case of 6-h infusions (122 +/- 35 micrograms/ml) and in the case of 34-h infusions (23.2 +/- 4.9 micrograms/ml) and the duration of VP-16 concentrations with > 10 and > 1 microgram/ml. Drug levels above these thresholds were always longer in case of 34-h infusions. In 8 of 16 patients VP-16 concentrations were measured in plasma samples at the time of BMT ranging from 80 to 820 ng/ml. The two different schedules for VP-16 administration, either given as a 6-h infusion or as a 34-h infusion, are bioequivalent in pharmacokinetic terms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗