Recruitment of distinct immune cell populations to the lung after intratracheal TLR4 signaling activation by two different stimulations

The toll-like receptor 4 (TLR4)-mediated immune response is considered as one of the triggers of acute respiratory distresssyndrome. The agonistic monoclonal antibody UT12 specific for the TLR4/MD2 complex induces immune activation in a mannerdistinct from lipopolysaccharide (LPS). In order to compare the effects of this differential TLR4 signaling activation, we examinedimmune cell recruitment to the lung following intratracheal inoculation with UT12 and LPS in mice. The increase in pulmonaryneutrophils was much higher after LPS treatment compared with UT12 treatment, while CD11bhiCD11＋cells increased to similarlevels following both treatments. These changes were MyD88-dependent and TRIF-independent. These differential effects onimmune cell recruitment to the lung suggest distinct underlying mechanisms in response to TLR4 stimulation. These findingsfurther indicate that TLR signaling can lead to different outcomes depending on the ligand and activation pathway, which mayrelate to the complex pathogenesis of inflammatory lung diseases

Efficient and Directive Generation of Two Distinct Endoderm Lineages from Human ESCs and iPSCs by Differentiation Stage-Specific SOX17 Transduction

The establishment of methods for directive differentiation from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is important for regenerative medicine. Although Sry-related HMG box 17 (SOX17) overexpression in ESCs leads to differentiation of either extraembryonic or definitive endoderm cells, respectively, the mechanism of these distinct results remains unknown. Therefore, we utilized a transient adenovirus vector-mediated overexpression system to mimic the SOX17 expression pattern of embryogenesis. The number of alpha-fetoprotein-positive extraembryonic endoderm (ExEn) cells was increased by transient SOX17 transduction in human ESC- and iPSC-derived primitive endoderm cells. In contrast, the number of hematopoietically expressed homeobox (HEX)-positive definitive endoderm (DE) cells, which correspond to the anterior DE in vivo, was increased by transient adenovirus vector-mediated SOX17 expression in human ESC- and iPSC-derived mesendoderm cells. Moreover, hepatocyte-like cells were efficiently generated by sequential transduction of SOX17 and HEX. Our findings show that a stage-specific transduction of SOX17 in the primitive endoderm or mesendoderm promotes directive ExEn or DE differentiation by SOX17 transduction, respectively

Requirement of Interaction between Mast Cells and Skin Dendritic Cells to Establish Contact Hypersensitivity

The role of mast cells (MCs) in contact hypersensitivity (CHS) remains controversial. This is due in part to the use of the MC-deficient Kit W/Wv mouse model, since Kit W/Wv mice congenitally lack other types of cells as a result of a point mutation in c-kit. A recent study indicated that the intronic enhancer (IE) for Il4 gene transcription is essential for MCs but not in other cell types. The aim of this study is to re-evaluate the roles of MCs in CHS using mice in which MCs can be conditionally and specifically depleted. Transgenic Mas-TRECK mice in which MCs are depleted conditionally were newly generated using cell-type specific gene regulation by IE. Using this mouse, CHS and FITC-induced cutaneous DC migration were analyzed. Chemotaxis assay and cytoplasmic Ca2+ imaging were performed by co-culture of bone marrow-derived MCs (BMMCs) and bone marrow-derived dendritic cells (BMDCs). In Mas-TRECK mice, CHS was attenuated when MCs were depleted during the sensitization phase. In addition, both maturation and migration of skin DCs were abrogated by MC depletion. Consistently, BMMCs enhanced maturation and chemotaxis of BMDC in ICAM-1 and TNF-α dependent manners Furthermore, stimulated BMDCs increased intracellular Ca2+ of MC upon direct interaction and up-regulated membrane-bound TNF-α on BMMCs. These results suggest that MCs enhance DC functions by interacting with DCs in the skin to establish the sensitization phase of CHS

Pectus Excavatum Repair: Review of 80 Cases in 32 years

We examined the results for pectus excavatum (PE) repair using conventional methods?sternal elevation by modified Ravitch procedure (SEMR), sternal elevation elevation by metal struts (SEMS), sternal turnover (ST) and costoplasty (CP)?and minimally invasive repair of PE (MIRPE) in 80 patients (65 boys and 15 girls) operated between July 1972 and March 2005 at the First Department of Surgery, Nagasaki University Hospital. Of 80 patients, 23 (28.8%) had asymmetric PE, while 57 (71.2%) had symmetric PE. The medians of cosmetic appearance index, functional impairment index and CT index were 0.022, 0.160 and 5.0395, respectively. A significant (p<0.0001) difference was observed among the operative methods for operating time, blood loss and hospital stay; the median of operating time was 85, 252.5, 145, 170 and 170 min for MIRPE, ST, CP, SEMR and SEMS, respectively; the median of blood loss was 5, 299.5, 243, 105.5 and 547.5 mL for MIRPE, ST, CP, SEMR and SEMS, respectively; the median of hospital stay was 10, 18.5, 30.5, 9.0 and 23.5 days for MIRPE, ST, CP, SEMR and SEMS, respectively. Postoperative complications were noted in 23 patients (28.8%), and the most common complication was wound infections. Epidural analgesia was used for postoperative pain control in 12 (75.0%) of 16 patients receiving MIRPE and 4 (7.7%) of 52 patients receiving ST in 1991 or later. The present study suggests that SEMR and MIRPE will be most versatile methods for children among the 5 operation procedures because of minimum invasion and short hospital stay; MIRPE has advantages that it has no incision of anterior chest wall and that it does not require resection of rib cartilages