Optimal conditions for lentiviral transduction of engrafting human CD34+ cells.

Cytokines are required for γ-retroviral transduction of human CD34+ cells. However, cytokines may reduce engraftment of CD34+ cells and may not be necessary for their lentiviral transduction. We sought to optimize transduction and engraftment of human CD34+ cells using lentiviral vectors.

Prostaglandin E2 enhances human cord blood stem cell xenotransplants and shows long-term safety in preclinical nonhuman primate transplant models.

Hematopoietic stem cells (HSCs) are used in transplantation therapy to reconstitute the hematopoietic system. Human cord blood (hCB) transplantation has emerged as an attractive alternative treatment option when traditional HSC sources are unavailable; however, the absolute number of hCB HSCs transplanted is significantly lower than bone marrow or mobilized peripheral blood stem cells (MPBSCs). We previously demonstrated that dimethyl-prostaglandin E2 (dmPGE2) increased HSCs in vertebrate models.

A pilot study evaluating the safety and CD34+ cell mobilizing activity of escalating doses of plerixafor in healthy volunteers.

This study evaluated the safety and CD34+ cell mobilizing activity of escalating doses of plerixafor in healthy volunteers. Three cohorts of six subjects received two different doses of plerixafor separated by at least 2 weeks to allow for adequate pharmacodynamic wash-out. The following dosing cohorts were evaluated: 0·24 and 0·32 mg/kg (Cohort 1); 0·32 and 0·40 mg/kg (Cohort 2); and 0·40 and 0·48 mg/kg (Cohort 3).

The assessment of human erythroid output in NOD/SCID mice reconstituted with human hematopoietic stem cells.

The third-generation NOD/LtSz-scid/IL2Rγ(null) (NOD/SCID IL2Rγ(null)) mouse represents a significantly improved xenograft model allowing high levels of human leukocyte engraftment over extended follow up. One remaining limitation of this mouse model, however, is the low level of circulating human erythrocytes. We established a practical ex vivo erythroid culture system of xenograft marrow progenitors to enrich for human erythroid progeny.

Chicken HS4 insulators have minimal barrier function among progeny of human hematopoietic cells transduced with an HIV1-based lentiviral vector.

Position effects limit the curative potential of gene transfer strategies for the hemoglobinopathies by inducing clonal variability of transgene expression. We evaluated the mitigating effects of the chicken hypersensitivity site 4 (HS4) insulator among lentiviral vector-transduced human hematopoietic cells. We constructed various lentiviral vectors using a green fluorescent protein (GFP) reporter under the control of a reverse-oriented murine stem cell virus (MSCV)-long-term repeat (LTR) promoter or a reverse-oriented β-globin expression cassette.

The influence of progesterone alone and in combination with estradiol on ventricular action potential duration and triangulation in response to potassium channel inhibition.

Introduction: Females are at increased risk for torsades de pointes (TdP). Some evidence suggests that progesterone may protect against TdP, but few data exist regarding the effects of progesterone on cardiac repolarization. We determined the effects of progesterone alone and in combination with estradiol on ventricular action potential duration (APD) and triangulation in response to potassium channel inhibition.

Significant human beta-cell turnover is limited to the first three decades of life as determined by in vivo thymidine analog incorporation and radiocarbon dating.

Aims: Diabetes mellitus results from an absolute or relative deficiency of insulin-producing pancreatic β-cells. The turnover rate of adult human β-cells remains unknown. We employed two techniques to examine adult human islet β-cell turnover and longevity in vivo.

Cardiomyogenesis in the adult human heart.

Rationale: The ability of the human heart to regenerate large quantities of myocytes remains controversial, and the extent of myocyte renewal claimed by different laboratories varies from none to nearly 20% per year.

Objective: To address this issue, we examined the percentage of myocytes, endothelial cells, and fibroblasts labeled by iododeoxyuridine in postmortem samples obtained from cancer patients who received the thymidine analog for therapeutic purposes. Additionally, the potential contribution of DNA repair, polyploidy, and cell fusion to the measurement of myocyte regeneration was determined.

5% dimethyl sulfoxide (DMSO) and pentastarch improves cryopreservation of cord blood cells over 10% DMSO.

Background: Cell number and viability are important in cord blood (CB) transplantation. While 10% dimethyl sulfoxide (DMSO) is the standard medium, adding a starch to freezing medium is increasingly utilized as a cytoprotectant for the thawing process. Similar to hetastarch, pentastarch has the advantages of faster renal clearance and less effect on the coagulation system.

A randomized, controlled study of amiodarone for prevention of atrial fibrillation after transthoracic esophagectomy.

Objective: Atrial fibrillation is common after esophagectomy. The objective of this study was to determine the efficacy and safety of amiodarone for prevention of atrial fibrillation after transthoracic esophagectomy.

Methods: Eighty patients undergoing transthoracic esophagectomy were randomly, prospectively assigned to receive amiodarone (n = 40) or no prophylaxis (control group, n = 40).

Glutaredoxin 5 deficiency causes sideroblastic anemia by specifically impairing heme biosynthesis and depleting cytosolic iron in human erythroblasts.

Glutaredoxin 5 (GLRX5) deficiency has previously been identified as a cause of anemia in a zebrafish model and of sideroblastic anemia in a human patient. Here we report that GLRX5 is essential for iron-sulfur cluster biosynthesis and the maintenance of normal mitochondrial and cytosolic iron homeostasis in human cells. GLRX5, a mitochondrial protein that is highly expressed in erythroid cells, can homodimerize and assemble [2Fe-2S] in vitro.

Prophylaxis of atrial fibrillation after noncardiac thoracic surgery.

Atrial fibrillation (AF) occurs commonly after noncardiac thoracic surgery, including lobectomy, pneumonectomy and esophagectomy. While not as extensively investigated as AF following cardiac surgery, some strategies for prophylaxis of AF after noncardiac thoracic surgery have been studied. Evidence from prospective, randomized controlled studies supports the use of beta-blockers, diltiazem, amiodarone or magnesium for prevention of AF after pulmonary resection.

Allogeneic hematopoietic stem-cell transplantation for sickle cell disease.

Background: Myeloablative allogeneic hematopoietic stem-cell transplantation is curative in children with sickle cell disease, but in adults the procedure is unduly toxic. Graft rejection and graft-versus-host disease (GVHD) are additional barriers to its success. We performed nonmyeloablative stem-cell transplantation in adults with sickle cell disease.

Over a thousand ambulatory hernia repairs in a primary care setting.

Introduction: This paper outlines the development and feasibility of a dedicated ambulatory primary care hernia service and examines the outcomes achieved during the period 1 March 2005 to 31 December 2008.

Patients And Methods: A prospective analysis of 1164 patients who underwent abdominal wall hernia repair at Probus Surgical Centre during the study period. The operations were carried out by two GPs with a special interest (GPwSI) and one retired surgeon.

Word learning, phonological short-term memory, phonotactic probability and long-term memory: towards an integrated framework.

Word learning is studied in a multitude of ways, and it is often not clear what the relationship is between different phenomena. In this article, we begin by outlining a very simple functional framework that despite its simplicity can serve as a useful organizing scheme for thinking about various types of studies of word learning. We then review a number of themes that in recent years have emerged as important topics in the study of word learning, and relate them to the functional framework, noting nevertheless that these topics have tended to be somewhat separate areas of study.

A randomized trial evaluating amiodarone for prevention of atrial fibrillation after pulmonary resection.

Background: Atrial fibrillation (AF) occurs commonly after anatomic pulmonary resection. In this study, the efficacy of amiodarone for prevention of post-pulmonary resection AF was investigated.

Methods: One hundred thirty patients undergoing lobectomy, bilobectomy, or pneumonectomy were randomly assigned prospectively to receive amiodarone (n = 65) or no prophylaxis (control group, n = 65).

Development of a human immunodeficiency virus type 1-based lentiviral vector that allows efficient transduction of both human and rhesus blood cells.

Human immunodeficiency virus type 1 (HIV-1) vectors transduce rhesus blood cells poorly due to a species-specific block by TRIM5alpha and APOBEC3G, which target HIV-1 capsid and viral infectivity factor (Vif), respectively. We sought to develop a lentiviral vector capable of transducing both human and rhesus blood cells by combining components of both HIV-1 and simian immunodeficiency virus (SIV), including SIV capsid (sCA) and SIV Vif. A chimeric HIV-1 vector including sCA (chiHIV) was superior to the conventional SIV in transducing a human blood cell line and superior to the conventional HIV-1 vector in transducing a rhesus blood cell line.

Paroxysmal beta-adrenergic receptor-mediated alterations in ventricular repolarization at rapid heart rates during inhibition of delayed rectifier currents.

The contribution of the slow component of the delayed rectifier current (IKs) to ventricular repolarization is increased during rapid heart rates and prolonged repolarization. The objective was to characterize physiologically relevant paroxysmal beta-adrenergic receptor-mediated alterations on ventricular repolarization under these conditions. Paced guinea pig hearts were perfused with (1) control, (2) sparfloxacin (IKr inhibitor), or (3) sparfloxacin and HMR 1556 (IKs inhibitor).

Granulocyte colony-stimulating factor (G-CSF) administration in individuals with sickle cell disease: time for a moratorium?

Granulocyte colony-stimulating factor (G-CSF) is used commonly in an attempt to reduce the duration of neutropenia and hospitalization in patients undergoing chemotherapy and to obtain hematopoietic stem cells (HSC) for transplantation applications. Despite the relative safety of administration of G-CSF in most individuals, including subjects with sickle cell trait, severe and life-threatening complications have been reported when used in individuals with sickle cell disease (SCD), including those who were asymptomatic and undiagnosed prior to administration. The administration of G-CSF has now been reported in a total of 11 individuals with SCD.

Transient in vivo beta-globin production after lentiviral gene transfer to hematopoietic stem cells in the nonhuman primate.

Inherited disorders of globin synthesis remain desirable targets for hematopoietic stem cell (HSC)-based therapies. Gene transfer using retroviral vectors offers an alternative to allogeneic HSC transplantation by the permanent integration of potentially therapeutic genes into primary autologous HSCs. Although proof of principle has been demonstrated in humans, this approach has been met by formidable obstacles, and large-animal models have become increasingly important for the preclinical development of gene addition strategies.