Maternal dendritic cells influence fetal allograft response following murine in-utero hematopoietic stem cell transplantation.

Background: Intrauterine hematopoietic stem cell transplantation (IUT), potentially curative in congenital haematological disease, is often inhibited by deleterious immune responses to donor cells resulting in subtherapeutic donor cell chimerism (DCC). Microchimerism of maternal immune cells (MMc) trafficked into transplanted recipients across the placenta may directly influence donor-specific alloresponsiveness, limiting DCC. We hypothesized that dendritic cells (DC) among trafficked MMc influence the development of tolerogenic or immunogenic responses towards donor cells, and investigated if maternal DC-depletion reduced recipient alloresponsiveness and enhanced DCC.

Maternal microchimerism and cell-mediated immune-modulation enhance engraftment following semi-allogenic intrauterine transplantation.

Successful intrauterine hematopoietic cell transplantation (IUT) for congenital hemoglobinopathies is hampered by maternal alloresponsiveness. We investigate these interactions in semi-allogenic murine IUT. E14 fetuses (B6 females × BALB/c males) were each treated with 5E+6 maternal (B6) or paternal (BALB/c) bone marrow cells and serially monitored for chimerism (>1% engraftment), trafficked maternal immune cells, and immune responsiveness to donor cells.

Fetoscopic versus Ultrasound-Guided Intravascular Delivery of Maternal Bone Marrow Cells in Fetal Macaques: A Technical Model for Intrauterine Haemopoietic Cell Transplantation.

Introduction: Significant limitations with existing treatments for major haemoglobinopathies motivate the development of effective intrauterine therapy. We assessed the feasibility of fetoscopic and ultrasound-guided intrauterine haemopoietic cell transplantation (IUHCT) in macaque fetuses in early gestation when haemopoietic and immunological ontogeny is anticipated to enable long-term donor cell engraftment.

Material And Methods: Fluorescent-labelled bone marrow-derived mononuclear cells from 10 pregnant Macaca fascicularis were injected into their fetuses at E71-114 (18.

In-vivo evaluation of subcutaneously implanted cell-loaded apatite microcarriers for osteogenic potency.

Cell-loaded apatite microcarriers present as potential scaffolds for direct in-vivo delivery of cells post-expansion to promote bone regeneration. The objective of this study was to evaluate the osteogenic potency of human foetal mesenchymal stem cells (hfMSC)-loaded apatite microcarriers when implanted subcutaneously in a mouse model. This was done by examining for ectopic bone formation at 2 weeks, 1 month and 2 months, which were intended to coincide with the inflammation, healing and remodelling phases, respectively.

Neo-vascularization and bone formation mediated by fetal mesenchymal stem cell tissue-engineered bone grafts in critical-size femoral defects.

Tissue-engineered bone grafts (TEBG) require highly osteogenic cell sources for use in fracture repair applications. Compared to other sources of mesenchymal stem cells (MSC), human fetal MSC (hfMSC) have recently been shown to be more proliferative and osteogenic. We studied the functional performance of hfMSC-mediated TEBG in 7 mm rat femoral critical-sized bone defects (CSD).

Microgel iron oxide nanoparticles for tracking human fetal mesenchymal stem cells through magnetic resonance imaging.

Stem cell transplantation for regenerative medicine has made significant progress in various injury models, with the development of modalities to track stem cell fate and migration post-transplantation being currently pursued rigorously. Magnetic resonance imaging (MRI) allows serial high-resolution in vivo detection of transplanted stem cells labeled with iron oxide particles, but has been hampered by low labeling efficiencies. Here, we describe the use of microgel iron oxide (MGIO) particles of diameters spanning 100-750 nm for labeling human fetal mesenchymal stem cells (hfMSCs) for MRI tracking.

Dynamic changes in microtubules and early development of reconstructed embryos after somatic cell nuclear transfer in a non-human primate.

In order to improve somatic cell nuclear transfer (SCNT) efficiency and to understand cellular changes in SCNT, the dynamic changes in microtubules/DNA and early development of SCNT embryos with single or multiple pronuclei were investigated, along with activation timing on efficiency of SCNT, were studied in the Cynomolgus monkey. The confocal images showed that microtubules assembled around condensed DNA at 1h after cell injection; normal or abnormal reconstructed spindle formed at 2 h after cell injection; and reconstructed spindle separated at 2 h after activation. The results of nuclear formation showed that 61.

An e-learning portal for nurses in Singapore General Hospital.

Singapore General Hospital (SGH) pioneered e-learning systems in Singapore as a knowledge management initiative for nurses. This paradigm shift in nursing education is a proactive step taken to address the increasing sophistication of healthcare systems, expanding demand and perennial shortage of nursing talent. E-learning has been a success at SGH, through providing systematic sharing of knowledge and capture of experience, through both formal and informal online channels.

Nursing intranet for communication and knowledge management.

Leveraging on staff's familiarity with the global Internet and the Hospital Information Technology infrastructure, nurses at Singapore General Hospital (SGH) first took the challenge to design and develop an in-house intranet, which serves as a communication network in 1997. This nursing intranet was further enhanced using multi-media technology to develop e-learning modules on nursing specialty, skill-based, and audio slides presentation training. In addition, it also serves as a repository for policies, operational, nursing procedure documents and catalogue of forms, patient instruction pamphlets.

Early development of reconstructed embryos after somatic cell nuclear transfer in a non-human primate.

To improve efficiency and assess variation in nuclear transfer techniques in non-human primates, we investigated the following factors: type of donor cell, interval between enucleation and cell injection, activation after electrical pulsing and cytokinesis inhibitors. An average of 16.4 oocytes were recovered from 91 retrievals; however, 15 (14%) additional retrieval attempts yielded no oocytes due to a failure of follicular stimulation.

Aberrant profile of gene expression in cloned mouse embryos derived from donor cumulus nuclei.

Somatic cell nuclear transfer has successfully been used to clone several mammalian species including the mouse, albeit with extremely low efficiency. This study investigated gene expression in cloned mouse embryos derived from cumulus cell donor nuclei, in comparison with in vivo fertilized mouse embryos, at progressive developmental stages. Enucleation was carried out by the conventional puncture method rather than by the piezo-actuated technique, whereas nuclear transfer was achieved by direct cumulus nuclear injection.

Developmental competence of transported in-vitro matured macaque oocytes.

This study examines in-vitro maturation (IVM) in a non-human primate model, Macaca fascicularis. The animals had hormonal injections and laparoscopic oocyte retrieval (OR)) at 12- and 24- h after human chorionic gonadotrophin (HCG). The immature oocytes were placed in tightly capped tubes containing pre-equilibrated IVM medium and transported for 5 h in a dry portable 37 degrees C incubator without CO2 supplement.

Influence of cysteamine supplementation and culture in portable dry-incubator on the in vitro maturation, fertilization and subsequent development of mouse oocytes.

The need to transport oocytes and embryos between two laboratories have prompted us to evaluate the effects of in vitro maturation of immature mouse oocytes in a CO2-deficient dry heat portable incubator and subsequent in vitro development of these fertilized mouse oocytes in a standard CO2 incubator. In addition, the effects of cysteamine supplementation on maturation rate and embryonic development during in vitro maturation (IVM) and culture of embryos in the portable incubator were also investigated. Germinal vesicle stage mouse oocytes, recovered at 40-h post-FSH from 6- to 8-week-old C57BL/6xCBA F1 healthy female mice, were matured in vitro in a modified TCM-199 supplemented with or without 100 microM cysteamine in a standard incubator (5% CO2; 37 degrees C) or cultured in a CO2-deficient dry heat portable incubator for 5 h at 37 degrees C and thereafter transferred to a standard incubator for further culture.

The first cell cycle after transfer of somatic cell nuclei in a non-human primate.

Production of genetically identical non-human primates through somatic cell nuclear transfer (SCNT) can provide diseased genotypes for research and clarify embryonic stem cell potentials. Understanding the cellular and molecular changes in SCNT is crucial to its success. Thus the changes in the first cell cycle of reconstructed zygotes after nuclear transfer (NT) of somatic cells in the Long-tailed Macaque (Macaca fascicularis) were studied.