scholarly journals Secretion of phosphomannosyl-deficient arylsulphatase A and cathepsin D from isolated human macrophages

2002 ◽  
Vol 368 (3) ◽  
pp. 845-853 ◽  
Author(s):  
Nicole MUSCHOL ◽  
Ulrich MATZNER ◽  
Stephan TIEDE ◽  
Volkmar GIESELMANN ◽  
Kurt ULLRICH ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Transplantation ◽  
Cell Line ◽  
Marrow Transplantation ◽  
Cathepsin D ◽  
Lysosomal Enzymes ◽  
Brain Cells ◽  
Therapeutic Effects ◽  
Human Macrophages ◽  
Arylsulphatase A

The transfer of macrophage-secreted arylsulphatase A (ASA) to enzyme-deficient brain cells is part of the therapeutic concept of bone marrow transplantation in lysosomal storage diseases. Here we have investigated this transfer in vitro. The uptake of 125I-labelled recombinant human ASA purified from ASA-overexpressing mouse embryonic fibroblasts deficient for mannose 6-phosphate (M6P) receptors in a mouse ASA-deficient astroglial cell line was completely inhibited by M6P. In contrast, when ASA-deficient astroglial cells were incubated with secretions of [35S]methionine-labelled human macrophages or mouse microglia, containing various lysosomal enzymes, neither ASA nor cathepsin D (CTSD) were detected in acceptor cells. Co-culturing of metabolically labelled macrophages with ASA-deficient glial cells did not result in an M6P-dependent transfer of ASA or CTSD between these two cell types. In secretions of [33P]phosphate-labelled macrophages no or weakly phosphorylated ASA and CTSD precursor polypeptides were found, whereas both intracellular and secreted ASA from ASA-overexpressing baby hamster kidney cells displayed 33P-labelled M6P residues. Finally, the uptake of CTSD from secretions of [35S]methionine-labelled macrophages in rat hepatocytes was M6P-independent. These data indicated that lysosomal enzymes secreted by human macrophages or a mouse microglial cell line cannot be endocytosed by brain cells due to the failure to equip newly synthesized lysosomal enzymes with the M6P recognition marker efficiently. The data suggest that other mechanisms than the proposed M6P-dependent secretion/recapture of lysosomal enzymes might be responsible for therapeutic effects of bone marrow transplantation in the brain.

scholarly journals Optimization of busulfan dosage in children undergoing bone marrow transplantation: a pharmacokinetic study of dose escalation

Blood ◽  
1992 ◽  
Vol 80 (9) ◽  
pp. 2425-2428 ◽  
Author(s):  
AM Yeager ◽  
JE Jr Wagner ◽  
ML Graham ◽  
RJ Jones ◽  
GW Santos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Body Weight ◽  
Bone Marrow Transplantation ◽  
Young Children ◽  
Marrow Transplantation ◽  
Antineoplastic Agent ◽  
Area Under The Curve ◽  
Therapeutic Effects ◽  
Older Children ◽  
The Mean

Abstract Busulfan (BU) is a widely used myeloablative and antineoplastic agent in clinical bone marrow transplantation (BMT). The lower incidence of BU-associated toxicities and lower therapeutic effectiveness in young children given BU doses based on body weight (ie, 16 mg/kg) is associated with altered pharmacokinetics of BU; the area under the curve (AUC) of BU concentration versus time is significantly less in these patients than those observed in older children and adults. To optimize BU dosage in young BMT recipients, we developed a dosage regimen based on body surface area (BSA) and determined BU pharmacokinetics and BU-associated toxicities. Seven children (median age, 3.9 years, range, 1.1 to 5.7) undergoing allogeneic or autologous BMT for leukemia received 40 mg/m2/dose BU every 6 hours for 16 doses; BU concentrations were measured in the plasma, and AUCs were determined for each patient after the first and 13th doses. Expressed as a function of body weight, the median BU dosage was 26.4 mg/kg (range, 24.3 to 28.2), a 60% increase over the BU dosage based on body weight. Four patients developed mucositis, and one of them also developed nonfatal hepatic veno-occlusive disease (VOD). No patients receiving 40 mg/m2 BU developed neurotoxicity (eg, seizures) or interstitial pneumonitis. Prompt and sustained engraftment was observed in the allogeneic BMT recipients, and late graft failure was not seen. The mean BU AUCs were 1,105 mumol/L.min (range, 790 to 2,080) after the first dose and 1,022 mumol/L.min (range, 632 to 1,860) after the 13th dose of BU, comparable to the AUCs in adults given 16 mg/kg of BU. These studies suggest that, in young children, BSA-based dosing of BU (40 mg/m2) provides drug exposures (AUCs) closer to adult values with acceptable toxicities and may improve therapeutic effects.

scholarly journals Optimization of busulfan dosage in children undergoing bone marrow transplantation: a pharmacokinetic study of dose escalation

Blood ◽  
1992 ◽  
Vol 80 (9) ◽  
pp. 2425-2428 ◽  
Author(s):  
AM Yeager ◽  
JE Jr Wagner ◽  
ML Graham ◽  
RJ Jones ◽  
GW Santos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Body Weight ◽  
Bone Marrow Transplantation ◽  
Young Children ◽  
Marrow Transplantation ◽  
Antineoplastic Agent ◽  
Area Under The Curve ◽  
Therapeutic Effects ◽  
Older Children ◽  
The Mean

Busulfan (BU) is a widely used myeloablative and antineoplastic agent in clinical bone marrow transplantation (BMT). The lower incidence of BU-associated toxicities and lower therapeutic effectiveness in young children given BU doses based on body weight (ie, 16 mg/kg) is associated with altered pharmacokinetics of BU; the area under the curve (AUC) of BU concentration versus time is significantly less in these patients than those observed in older children and adults. To optimize BU dosage in young BMT recipients, we developed a dosage regimen based on body surface area (BSA) and determined BU pharmacokinetics and BU-associated toxicities. Seven children (median age, 3.9 years, range, 1.1 to 5.7) undergoing allogeneic or autologous BMT for leukemia received 40 mg/m2/dose BU every 6 hours for 16 doses; BU concentrations were measured in the plasma, and AUCs were determined for each patient after the first and 13th doses. Expressed as a function of body weight, the median BU dosage was 26.4 mg/kg (range, 24.3 to 28.2), a 60% increase over the BU dosage based on body weight. Four patients developed mucositis, and one of them also developed nonfatal hepatic veno-occlusive disease (VOD). No patients receiving 40 mg/m2 BU developed neurotoxicity (eg, seizures) or interstitial pneumonitis. Prompt and sustained engraftment was observed in the allogeneic BMT recipients, and late graft failure was not seen. The mean BU AUCs were 1,105 mumol/L.min (range, 790 to 2,080) after the first dose and 1,022 mumol/L.min (range, 632 to 1,860) after the 13th dose of BU, comparable to the AUCs in adults given 16 mg/kg of BU. These studies suggest that, in young children, BSA-based dosing of BU (40 mg/m2) provides drug exposures (AUCs) closer to adult values with acceptable toxicities and may improve therapeutic effects.

Intensive melphalan chemotherapy and cryopreserved autologous bone marrow transplantation for the treatment of refractory cancer.

1983 ◽  
Vol 1 (6) ◽  
pp. 359-367 ◽  
Author(s):  
H M Lazarus ◽  
R H Herzig ◽  
J Graham-Pole ◽  
S N Wolff ◽  
G L Phillips ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Transplantation ◽  
Marrow Transplantation ◽  
Autologous Bone Marrow Transplantation ◽  
Severe Infection ◽  
Autologous Bone Marrow ◽  
Maximum Tolerated Dose ◽  
High Dose ◽  
Therapeutic Effects ◽  
Autologous Bone

Thirty-three adult and pediatric patients with refractory malignancies were treated with escalating doses of melphalan (120-225 mg/m2 IV over 3 days) followed by reinfusion of previously harvested and cryopreserved autologous marrow. The hematological and nonhematological toxicities and the therapeutic effects of this regimen were evaluated. Increasing doses of melphalan did not alter the rate of decline nor the recovery of peripheral blood counts. Granulocyte (greater than 500/microL) and platelet count (greater than 20,000/microL) recovery occurred in a median of 19 (range 12-54) and 24 (range: 12-54) days after bone marrow transplantation, respectively. Five patients experienced severe infection, three of which were fatal, and one patient died due to thrombocytopenic hemorrhage. Toxicity to the gastrointestinal system was dose limiting. The maximum tolerated dose of melphalan was 180 mg/m2; only three of 24 patients experienced severe stomatitis, esophagitis, and diarrhea at this level or less, while eight of nine patients at 225 mg/m2 were affected (p less than 0.005). Administration of cyclophosphamide (300 mg/m2 IV) 1 week before melphalan therapy did not reduce the incidence of severe gastrointestinal toxicity. Plasma melphalan concentration peaked 30-60 min after infusion (4.8-11.5 micrograms/mL) but declined rapidly. Cerebrospinal fluid concentration was 10% of the corresponding plasma concentration and was undetectable at 3 hours. Antitumor responses occurred in nine of 13 patients with malignant melanoma (five complete and four partial remissions), and ranged 2-12+ months with a median of 5 months. Four of six neuroblastomas demonstrated responses (three complete and one partial remission( lasting a median of 7.5 (range: 5-10) months. Other tumors in which this regimen had activity included breast cancer and Ewing's sarcoma. The overall response rate for the 33 patients was 30% complete remissions (10 patients) and 21% partial remissions (seven patients). High dose melphalan and autologous bone marrow transplantation is a promising therapy for patients with malignancies for which no effective treatment is known or for patients whose cancer is refractory to conventional therapeutic agents.

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