Bacterial meningitis from Rothia mucilaginosa in patients with malignancy or undergoing hematopoietic stem cell transplantation.

Opportunistic infections contribute to morbidity and mortality of patients undergoing hematopoietic stem cell transplantation and treatment for malignancies. Rothia mucilaginosa, a gram-positive bacterium, is responsible for rare, but often fatal meningitis in severely immunocompromised patients. We describe two cases of meningitis from discrete strains of R.

Correction of DNA protein kinase deficiency by spliceosome-mediated RNA trans-splicing and sleeping beauty transposon delivery.

Spliceosome-mediated RNA trans-splicing (SMaRT) is an emerging technology for the repair of defective pre-messenger RNA (pre-mRNA) molecules. It is especially useful in the treatment of genetic disorders involving large genes. Although viral vectors have been used for achieving long-lasting expression of trans-splicing molecules, the immunogenicity and suboptimal safety profiles associated with viral-based components could limit the widespread application of SMaRT in the repair of genetic defects.

A novel method for KIR-ligand typing by pyrosequencing to predict NK cell alloreactivity.

Studies have shown that KIR-ligand mismatching to predict NK cell alloreactivity may result in less relapse and better survival in patients with AML. KIR-ligands are distinguished by single nucleotide polymorphisms (SNPs) from HLA-B and HLA-C sequences. We hypothesized that pyrosequencing to determine KIR-ligand status by direct sequencing of the ligand epitope can be done as an alternative to high-resolution HLA-typing.

The host immune response is essential for the beneficial effect of adult stem cells after myocardial ischemia.

Objective: Multipotent adult progenitor cells (MAPCs) are adult stem cells derived from bone marrow. We investigated the capacity of MAPCs to aid in tissue healing after myocardial ischemia in mice with different levels of immune competence.

Methods: Adult murine C57BL/6 MAPCs were labeled with firefly luciferase and DsRed2 fluorescent protein and injected into the myocardium of immunocompetent C57BL/6 or T-, B- and natural killer-cell severe combined immunodeficient C57BL/6 Rag2/IL-2Rgammac(-/-) mice at the time of myocardial infarction (MI).

N-acetyl-L-cysteine improves outcome of advanced cerebral adrenoleukodystrophy.

Hematopoietic stem cell transplantation as a treatment for childhood cerebral adrenoleukodystrophy (ALD) has historically only been successful in early disease. As ALD is associated with oxidative damage, we reasoned that adjunctive therapy with an antioxidant agent, N-acetyl-L-cysteine (NAC), may provide protection from rapid neurologic decline in boys with advanced cerebral disease. We report three boys with advanced ALD, whose neurologic status and brain radiographic findings were stabilized by treatment including NAC 8-11 months after hematopoietic stem cell transplantation.

Hematopoietic reconstitution by multipotent adult progenitor cells: precursors to long-term hematopoietic stem cells.

For decades, in vitro expansion of transplantable hematopoietic stem cells (HSCs) has been an elusive goal. Here, we demonstrate that multipotent adult progenitor cells (MAPCs), isolated from green fluorescent protein (GFP)-transgenic mice and expanded in vitro for >40-80 population doublings, are capable of multilineage hematopoietic engraftment of immunodeficient mice. Among MAPC-derived GFP+CD45.

Engraftment and survival following hematopoietic stem cell transplantation for osteopetrosis using a reduced intensity conditioning regimen.

Autosomal recessive osteopetrosis (OP) is a disease characterized by osteoclast dysfunction, leading to multisystem morbidity and death of most affected children. Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for OP, but this patient population is particularly prone to post-transplant complications and death after myeloablative conditioning. To determine the potential of achieving improved overall outcomes in these patients by decreasing pre-transplant mortality, we investigated engraftment and survival following a reduced intensity regimen including busulfan, fludarabine and total lymphoid irradiation.

Sarcoma derived from cultured mesenchymal stem cells.

To study the biodistribution of MSCs, we labeled adult murine C57BL/6 MSCs with firefly luciferase and DsRed2 fluorescent protein using nonviral Sleeping Beauty transposons and coinfused labeled MSCs with bone marrow into irradiated allogeneic recipients. Using in vivo whole-body imaging, luciferase signals were shown to be increased between weeks 3 and 12. Unexpectedly, some mice with the highest luciferase signals died and all surviving mice developed foci of sarcoma in their lungs.

Marked increased risk of Epstein-Barr virus-related complications with the addition of antithymocyte globulin to a nonmyeloablative conditioning prior to unrelated umbilical cord blood transplantation.

Umbilical cord blood (UCB) is increasingly used as an alternative source of hematopoietic stem cells for transplantation for patients who lack a suitable sibling donor. Despite concerns about a possible increased risk of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disorder (PTLD) after UCB transplantation, early reports documented rates of PTLD comparable to those reported after HLA-matched unrelated marrow myeloablative (MA) transplantations. To further investigate the incidence of EBV PTLD after UCB transplantation and potential risk factors, we evaluated the incidence of EBV-related complications in 335 patients undergoing UCB transplantation with an MA or nonmyeloablative (NMA) preparative regimen.

Optimization of conditioning for marrow transplantation from unrelated donors for patients with aplastic anemia after failure of immunosuppressive therapy.

In 87 patients with aplastic anemia who failed to respond to immunosuppressive treatment, we determined the minimal dose of total body irradiation (TBI) required when added to antithymocyte globulin (ATG, 30 mg/kg x 3) plus cyclophosphamide (CY, 50 mg/kg x 4) to achieve engraftment of unrelated donor marrow. TBI was started at 3 x 200 cGy, to be escalated or deescalated in steps of 200 cGy depending on graft failure or toxicity. Patients were aged 1.

Adeno-associated virus-mediated delivery of a mutant endostatin in combination with carboplatin treatment inhibits orthotopic growth of ovarian cancer and improves long-term survival.

A human ovarian cancer cell line, which migrates to mouse ovaries and establishes peritoneal carcinomatosis, was used to evaluate the cooperative effect of an antiangiogenic gene therapy combined with chemotherapy. The ovarian carcinoma cell line MA148 was genetically modified by "Sleeping Beauty" transposon-mediated delivery of DsRed2 fluorescent protein. Stable, high-level expression of DsRed protein enabled in vivo imaging of peritoneal dissemination of ovarian cancer.

Host factors that impact the biodistribution and persistence of multipotent adult progenitor cells.

Multipotent adult progenitor cells (MAPCs) are marrow-derived pluripotent stem cells with a broad differentiation potential. We sought to identify factors that affect adoptively transferred MAPCs. In vitro, MAPCs expressed low levels of major histocompatibility complex (MHC) antigens, failed to stimulate CD4(+) and CD8(+) T-cell alloresponses, and were targets of NK cytolysis.

Cardiac functional and histopathologic findings in humans and mice with mucopolysaccharidosis type I: implications for assessment of therapeutic interventions in hurler syndrome.

Hurler syndrome (mucopolysaccharidosis type I [MPS I]) is a uniformly lethal autosomal recessive storage disease caused by absence of the enzyme alpha-l-iduronidase (IDUA), which is involved in lysosomal degradation of sulfated glycosaminoglycans (GAGs). Cardiomyopathy and valvar insufficiency occur as GAGs accumulate in the myocardium, spongiosa of cardiac valves, and myointima of coronary arteries. Here we report the functional, biochemical, and morphologic cardiac findings in the MPS I mouse.

Stable gene transfer and expression in human primary T cells by the Sleeping Beauty transposon system.

The Sleeping Beauty (SB) transposon system is a nonviral DNA delivery system in which a transposase directs integration of an SB transposon into TA-dinucleotide sites in the genome. To determine whether the SB transposon system can mediate stable gene expression in human T cells, primary peripheral blood lymphocytes (PBLs) were nucleofected with SB vectors carrying a DsRed reporter gene. Plasmids containing the SB transposase on the same molecule as (cis) or on a molecule separate from (trans) the SB transposon mediated long-term and stable reporter gene expression in human primary T cells.

A picornaviral 2A-like sequence-based tricistronic vector allowing for high-level therapeutic gene expression coupled to a dual-reporter system.

The 2A-like sequences from members of the picornavirus family were utilized to construct a tricistronic vector bearing the human iduronidase (IDUA) gene along with the firefly luciferase and DsRed2 reporter genes. The 2A-like sequences mediate a cotranslational cleavage event resulting in the release of each individual protein product. Efficient cleavage was observed and all three proteins were functional in vitro and in vivo, allowing for supratherapeutic IDUA enzyme levels and the coexpression of luciferase and DsRed2 expression, which enabled us to track gene expression.

Real-time in vivo imaging of stem cells following transgenesis by transposition.

Previous studies have identified Sleeping Beauty transposons as efficient vectors for nonviral gene delivery in mammalian cells. However, studies demonstrating the usefulness of transposons as gene delivery vehicles into adult stem cells are lacking. Multipotent adult progenitor cells (MAPC) are nonhematopoietic stem cells with the capacity to form most, if not all, cell types of the body and as such hold great therapeutic potential.

Intravenous 6-mercaptopurine decreases salvage after relapse in childhood acute lymphoblastic leukemia: a report from the Children's Cancer Group study CCG 1922.

Purpose: To compare outcomes of patients with NCI standard risk acute lymphoblastic leukemia (ALL) who relapsed after being randomized to receive either oral or intravenous 6-mercaptopurine (6MP) in the Children's Cancer Group study CCG 1922.

Patients And Methods: CCG 1922 accrued patients from March 1993 to August 1995. A total of 1,060 patients were randomly assigned to four treatment groups: oral 6MP plus prednisone (OP), intravenous 6MP plus prednisone (IP), oral 6MP plus dexamethasone (OD), and intravenous 6MP plus dexamethasone (ID).

Induction of comprehensible models for gene expression datasets by subgroup discovery methodology.

Finding disease markers (classifiers) from gene expression data by machine learning algorithms is characterized by a high risk of overfitting the data due the abundance of attributes (simultaneously measured gene expression values) and shortage of available examples (observations). To avoid this pitfall and achieve predictor robustness, state-of-the-art approaches construct complex classifiers that combine relatively weak contributions of up to thousands of genes (attributes) to classify a disease. The complexity of such classifiers limits their transparency and consequently the biological insights they can provide.

Germline mutations in BRCA2: shared genetic susceptibility to breast cancer, early onset leukemia, and Fanconi anemia.

The breast cancer susceptibility gene BRCA2 has recently been identified as identical to the Fanconi anemia (FA) gene FANCD1. Here we expand the clinical implications of this discovery. Notably, we identified 6 children in 5 kindreds exhibiting the co-occurrence of BRCA2 mutations, FA, and early onset acute leukemia.

Transplacental and other routes of cancer transmission between individuals.

Cancer in pregnancy is not rare, and the possibility of transmission of malignancy from mother to child, while infrequent, represents a clinical challenge for the primary pediatric hematologist-oncologist. The authors summarize all reported cases of vertically transmitted cancer and review other reported cases of person-to-person transfer of malignancy. As these cases represent a unique physiologic model of tumor transplantation, the biology of cancer transmission is discussed and provisional guidelines are given for the screening of infants born to women with cancer.

Acute polyosteal osteomyelitis in a patient with congenital ichthyosis and acute lymphoblastic leukemia.

Osteomyelitis can develop after bacteremia in children and is a rare complication of chemotherapy for acute lymphoblastic leukemia. A child with congenital ichthyosis, acute lymphoblastic leukemia and multifocal hematogenous osteomyelitis is described herein. A breached skin barrier secondary to ichthyosis during induction chemotherapy, coupled with impaired immunity, likely provided the opportunity for bacterial seeding, leading to an extensive multifocal osteomyelitis.