A model of modified meta-iodobenzylguanidine conjugated gold nanoparticles for neuroblastoma treatment

Iodine-131 meta-iodobenzylguanidine (¹³¹I-mIBG) has been utilized as a standard treatment to minimize adverse side effects by targeting therapies to bind to the norepinephrine transporter (NET) expressed on 90% of neuroblastoma cells. However, only a minority of patients who receive ¹³¹I-mIBG radiotherapy have clinical responses, and these are usually not curative. In this study, novel ligand-conjugated gold nanoparticles (GNPs) based on mIBG were synthesized and evaluated biologically with neuroblastoma cells in vitro. To induce specific internalization to the tumor cells and utilize it as a model for radioenhancement, ¹²⁷I-modified mIBG was successfully synthesized and grafted covalently to the surface of carboxylated PEG-GNPs. 49.28% of the novel mIBG derivative was grafted on carboxylated PEG-GNPs. The particles were stable and not toxic to the normal fibroblast cell line, L929, even at the highest concentration tested (10¹³ NPs per mL) at 24, 48, and 72 h. Moreover, the cellular uptake of the model was decreased significantly in the presence of a NET inhibitor, suggesting that there was specific internalization into neuroblastoma cells line (SH-SY5Y) via the NET. Therefore, this model provides useful guidance toward the design of gold nanomaterials to enhance the efficiency of ¹³¹I-mIBG treatment in neuroblastoma patients. However, the investigation of radio-therapeutic efficiency after radioisotope ¹³¹I substitution will be further conducted in a radiation safety laboratory using an animal model.

¹²⁷I-modified mIBG was successfully synthesized and grafted covalently to the surface of carboxylated PEG-GNPs. The particles were not toxic to the normal fibroblast cells while specifically internalized into neuroblastoma cells line via NET.     

Suppression of adrenal function in children with acute lymphoblastic leukemia following induction therapy with corticosteroid and other cytotoxic agents

OBJECTIVE: To evaluate adrenal function in children with acute lymphoblastic leukemia (ALL) after induction therapy with corticosteroid and other cytotoxic agents.Study design Children with ALL (N=24) were treated with prednisolone (40 mg/m(2) per day) for 28 days during the induction phase followed by 1 week of oral dexamethasone every 4 weeks. A low-dose (1 microg) adrenocorticotropin (ACTH) test was performed 2 weeks after discontinuation of prednisolone; it was repeated 2 weeks later and then every 4 weeks in patients with adrenal suppression until normal response was achieved. RESULTS: Adrenal suppression was found in 46% of patients at 2 weeks after discontinuation of prednisolone; it persisted in 38%, 29%, and 13% of patients through 4 weeks, 8 weeks, and 20 weeks, respectively. Adrenal suppression appeared to last significantly longer in children aged >or=5 years than in children aged <5 years. Four children developed febrile neutropenia; all belonged to the adrenal suppressed group and were unable to mount an adequate adrenal response to the stress. CONCLUSIONS: About 50% of children with ALL developed adrenal suppression 2 weeks after a 4-week induction therapy with prednisolone. The suppression could persist through 20 weeks and may hinder an adequate adrenal response during acute febrile illness.     

Allogeneic peripheral blood stem cell transplantation in children with homozygous beta-thalassemia and severe beta-thalassemia/hemoglobin E disease

To determine the outcome of children with homozygous beta-thalassemia (beta/beta) and severe beta-thalassemia/hemoglobin E disease (beta/E) who underwent allogeneic peripheral blood stem cell transplantation (PBSCT). The authors conducted a cohort study of allogeneic PBSCT in beta/beta and beta/E patients who had 6/6 or 5/6 HLA-matched sibling donors. All patients received a conditioning regimen including busulfan and cyclophosphamide, except one who received busul-fan and cyclophosphamide plus antithymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and methotrexate for eight patients and cyclosporine and mycophenolate mofetil for one patient. Donors received G-CSF for 4 days before leukapheresis collections. There were five beta/beta and four beta/E patients in this study. The median age was 9 years (range 1.5-10 years). The median CD34+ cell count was 7.4 x 10(6) cells/kg recipient body weight. All patients achieved neutrophil and platelet engraftment with a median time of 15 days and 21 days respectively. Acute GVHD grade 2 to 4 appeared in four patients (grade 2, n = 3; grade 4, n = 1). Three patients developed chronic GVHD (limited, n = 2; extensive, n = 1). All patients were alive with a median follow-up time of 23 months (range 7-52 months). Neither graft failure nor graft rejection was observed. Allogeneic PBSCT is feasible for children with beta/beta and beta/E, although the incidence of GVHD was apparently high compared with bone marrow transplant study in Thais.     

The impact of early resection of primary neuroblastoma on the survival of children older than 1 year of age with stage 4 disease: the St. Jude Children's Research Hospital Experience

BACKGROUND: It remains unclear whether primary tumor resection benefits patients with metastatic neuroblastoma. The authors assessed the impact of extent and timing of resection on outcome in these patients. METHODS: The authors reviewed the records of 124 patients > 1 year of age at diagnosis of International Neuroblastoma Staging System Stage 4 neuroblastoma. The survival estimates of those who did and did not have a gross total resection (GTR) and of those who had initial versus delayed GTR were compared. Surgical complications were reviewed. RESULTS: The 5-year survival estimates were comparable for the 90 patients who had a GTR and the 17 who underwent surgery but did not have a GTR (29.9% +/- 5.1% [standard error] vs. 29.4% +/- 10.1%). The 7 patients who underwent GTR at the time of diagnosis had a higher 5-year survival estimate than the 83 patients who had a GTR after induction chemotherapy (83.3% +/- 13.9% vs. 25.2% +/- 5.0%) (P = 0.001). Five-year event-free survival estimates were similarly higher in the initial-GTR group (57.1% +/- 18.7% vs. 14.5% +/- 4.2%) (P = 0.002). These two groups did not differ significantly in age at diagnosis (P = 0.118), site of primary tumor (P = 0.34), MYCN amplification status (P = 1), serum lactate dehydrogenase activity at diagnosis (P = 0.34), or treatment protocol (P = 0.22). Twenty-two (21%) patients had a surgical complication. CONCLUSIONS: In this small cohort of patients with metastatic neuroblastoma, GTR at the time of diagnosis offered a survival benefit. Further prospective studies are warranted before this approach can be applied to all patients with metastatic neuroblastoma.     

Hypercalcemia and altered biochemical bone markers in post-bone marrow transplantation osteopetrosis: a case report and literature review

Autosomal recessive osteopetrosis is a rare disorder of bone resorption defect that results in generalized sclerotic bones and bone marrow failure. Allogeneic BMT is the only treatment for cure. One of the complications following a successful BMT is hypercalcemia that is a unique complication in this group of patients. We report a three-yr-old boy with osteopetrosis who developed hypercalcemia following the successful BMT. His maximal calcium level was 13.3 mg/dL. Markedly increased both bone formation and resorption markers were demonstrated along with hypercalcemia. These findings indicated an active donor-derived osteoclastic function and thus bone resorption following the successful donor engraftment in the patient. Treatment with hyperhydration, furosemide and bone resorption inhibitors, calcitonin, and bisphosphonate led to normalization of the serum calcium level. Bone resorption but not bone formation marker was persistently elevated despite having normocalcemia during a 16.5-month follow-up period.