An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding

The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators

Small-cell neuroendocrine carcinoma of the breast

A small-cell carcinoma is one of the histologic subtypes of primary neuroendocrine carcinomas of the breast. A small-cell carcinoma is a rare entity of the breast and exhibits similar morphologic features as neuroendocrine tumors of the gastrointestinal tract and lung. We present the imaging and pathologic findings of a primary small-cell neuroendocrine carcinoma of the breast. This is the first report of a primary small-cell carcinoma arising from the breast in Korea

A Novel Selective Sphingosine Kinase 2 Inhibitor, HWG-35D, Ameliorates the Severity of Imiquimod-Induced Psoriasis Model by Blocking Th17 Differentiation of Naïve CD4 T Lymphocytes

Sphingosine kinases (SK) catalyze the phosphorylation of sphingosine to generate sphingosine-1-phosphate. Two isoforms of SK (SK1 and SK2) exist in mammals. Previously, we showed the beneficial effects of SK2 inhibition, using ABC294640, in a psoriasis mouse model. However, ABC294640 also induces the degradation of SK1 and dihydroceramide desaturase 1 (DES1). Considering these additional effects of ABC294640, we re-examined the efficacy of SK2 inhibition in an IMQ-induced psoriasis mouse model using a novel SK2 inhibitor, HWG-35D, which exhibits nM potency and 100-fold selectivity for SK2 over SK1. Topical application of HWG-35D ameliorated IMQ-induced skin lesions and normalized the serum interleukin-17A levels elevated by IMQ. Application of HWG-35D also decreased skin mRNA levels of interleukin-17A, K6 and K16 genes induced by IMQ. Consistent with the previous data using ABC294640, HWG-35D also blocked T helper type 17 differentiation of naive CD4+ T cells with concomitant reduction of SOCS1. Importantly, HWG-35D did not affect SK1 or DES1 expression levels. These results reaffirm an important role of SK2 in the T helper type 17 response and suggest that highly selective and potent SK2 inhibitors such as HWG-35D might be of therapeutic use for the treatment of psoriasis

Combined Effects of Surface Morphology and Mechanical Straining Magnitudes on the Differentiation of Mesenchymal Stem Cells without Using Biochemical Reagents

Existing studies examining the control of mesenchymal stem cell (MSC) differentiation into desired cell types have used a variety of biochemical reagents such as growth factors despite possible side effects. Recently, the roles of biomimetic microphysical environments have drawn much attention in this field. We studied MSC differentiation and changes in gene expression in relation to osteoblast-like cell and smooth muscle-like cell type resulting from various microphysical environments, including differing magnitudes of tensile strain and substrate geometries for 8 days. In addition, we also investigated the residual effects of those selected microphysical environment factors on the differentiation by ceasing those factors for 3 days. The results of this study showed the effects of the strain magnitudes and surface geometries. However, the genes which are related to the same cell type showed different responses depending on the changes in strain magnitude and surface geometry. Also, different responses were observed three days after the straining was stopped. These data confirm that controlling microenvironments so that they mimic those in vivo contributes to the differentiation of MSCs into specific cell types. And duration of straining engagement was also found to play important roles along with surface geometry

Lepidopterous Insect Fauna of Gyeongju National Park in Korea

AbstractLepidopterous insect fauna of Gyeongju National Park, was investigated during 25-28 April and 10-11 August 2007, especially in Mt. Namsan Zone. In total, 150 species of 21 families belonging to Lepidoptera were identified through this study. Therefore, a total of 183 species under 25 families are recorded from Gyeongju National Park, including the previous studies

ArmA and RmtB Were the Predominant 16S RMTase Genes Responsible for Aminoglycoside-resistant Isolates in Korea

Pathogenic gram-negatives that produce 16S ribosomal RNA methyltransferases (16S RMTases) have already been distributed all over the world. To investigate the predominance of aminoglycoside resistance associated with 16S RMTases in Korea, we collected a total of 222 amikacin resistant Gram-negative clinical isolates from patient specimens between 1999 and 2015 from three hospital banks across Korea. ArmA and nntB were the predominant 16S RMTase genes responsible for aminoglycoside-resistant isolates circulating in Korean community settings although only one rmtA-producing isolate was detected in 2006.1

Quantitatively Controlled Fabrication of Uniaxially Aligned Nanofibrous Scaffold for Cell Adhesion

In light of tissue engineering, development of a functional and controllable scaffold which can promote cell proliferation and differentiation is crucial. In this study, we introduce a controllable collection method of the electrospinning process for regularly-distributed and uniaxially oriented nanofiber scaffold and evaluate the effects of aligned nanofiber density on adhesion of dermal fibroblasts. The suggested spinning collector features an inclined void gap, which allows easy transfer of uniformly aligned fibers onto other surfaces. By undergoing multiple transfers, the density of the nanofibers can be quantitatively controlled. The resultant polycaprolactone (PCL) nanofibers had well-defined nanotopography in a 400–600 nm range. Human dermal fibroblasts were seeded on aligned nanofiber scaffolds of different densities achieved by varying the number of transfers. Cell morphology and actin stress fiber formation was accessed after seven days. The experimental results indicate that the contact guidance of the cells along the fiber alignment can be more activated with more than one guidance feature on a cell; that is, the high density of fiber is attained in so much that fiber spacing gets below the cell size

Pig-to-Nonhuman Primate (NHP) Naked Islet Xenotransplantation

Islet transplantation is an established therapy for selected type 1 diabetes (T1D) patients with severe hypoglycemic unawareness and glycemic liability despite of insulin treatment. However, the donor organ is limited. Porcine islets are the best alternative source to overcome this limitation, and pig-to-nonhuman primate (NHP) naked islet xenotransplantation studies are being performed worldwide. Several studies including our own have presented successful proof-of-concept results based on immunosuppression regimen including the anti-CD154 monoclonal antibody. Particularly, long-term control of diabetes by adult porcine islet transplantation has been demonstrated in five consecutive monkeys, and the longest survival was ~1000 days after transplantation. Currently, pig-to-NHP islet xenotransplantation based on clinically applicable immunosuppression regimen is being pursued. In this chapter, we will describe all the procedures of pig-to-NHP naked islet xenotransplantation: (1) the porcine islet isolation from designated pathogen-free (DPF) miniature pigs, (2) diabetes induction in monkeys, (3) transplantation procedure via the portal vein, (4) immune monitoring comprising humoral and cellular immunity after porcine islet transplantation, and finally (5) liver biopsy and subsequent immunohistochemical procedure in detail