The quantitative assessment of MHC II on thymic epithelium: implications in cortical thymocyte development

Yang, Soo Jung,Ahn, Sejin,Park, Chan Sik,Holmes, Kevin L,Westrup, Jenifer,Chang, Cheong Hee,Kim, Moon G Oxford University Press 2006 International immunology Vol.18 No.5

<P>The dynamics of MHC II expression in various thymic stromal compartments was investigated. By including MHC II in flow cytometry in addition to the cortical CDR1, medullary UEA-1 and pan-epithelial G8.8 markers, thymic stromal compartments were subdivided into at least six different populations. The total level of surface and cytoplasmic MHC II from fresh cortical thymic epithelial cells (cTECs) of normal mouse was as high as MHC II levels in medullary thymic epithelial cells (mTECs). MHC II levels as well as the percentages and cycling status of thymic epithelial cell populations expressing MHC II were not static during post-natal development, suggesting quantitative flexibility in presenting signals to the developing thymocytes. Although there was no evidence found for regulation of surface MHC II levels by TCR or by IFN-γ, the absence of class II transactivator reduced both the level of MHC II expression and the number of MHC II<SUP>+</SUP> cells. Surprisingly, MHC II molecules were found to form distinct focal aggregates on the surface of cTEC but not mTEC using high-resolution analysis by confocal microscopy. Moreover, these aggregates were formed independent of TCR or TCR-bearing cells in the thymus. These aggregates could potentially generate a functional unit containing a much higher local MHC II concentration to yield a higher avidity interaction. We discuss possible mechanisms for positive selection by weak interactions in the presence of such preformed MHC II aggregate units in cTEC.</P>

Management of complex surgical wounds of the back: identifying an evidence-based approach

Elizabeth G. Zolper,Meher A. Saleem,Kevin G. Kim,Mark D. Mishu,Sarah R. Sher,Christopher E. Attinger,Kenneth L. Fan,Karen K. Evans 대한성형외과학회 2021 Archives of Plastic Surgery Vol.48 No.6

Background Postoperative dehiscence and surgical site infection after spinal surgery can carry serious morbidity. Multidisciplinary involvement of plastic surgery is essential to minimizing morbidity and achieving definitive closure. However, a standardized approach is lacking. The aim of this study was to identify effective reconstructive interventions for the basis of an evidence-based management protocol. Methods A retrospective review was performed at a single tertiary institution for 45 patients who required 53 reconstruction procedures with plastic surgery for wounds secondary to spinal surgery from 2010 to 2019. Statistical analysis was performed for demographics, comorbidities, and treatment methods. Primary outcomes were postoperative complications, including dehiscence, seroma, and infection. The secondary outcome was time to healing. Results The overall complication rate was 32%, with dehiscence occurring in 17%, seroma in 15% and infection in 11% of cases. Median follow-up was 10 months (interquartile range, 4–23). Use of antibiotic beads did not affect rate of infection occurrence after wound closure (P=0.146). Use of incisional negative pressure wound therapy (iNPWT) was significant for reduced time to healing (P=0.001). Patients treated without iNPWT healed at median of 67.5 days while the patients who received iNPWT healed in 33 days. Demographics and comorbidities between these two groups were similar. Conclusions This data provides groundwork for an evidence-based approach to soft tissue reconstruction and management of dehiscence after spinal surgery. Timely involvement of plastic surgery in high-risk patients and utilization of evidence-based interventions such as iNPWT are essential for improving outcomes in this population.

<i>CAMK1D</i> amplification implicated in epithelial–mesenchymal transition in basal-like breast cancer

Bergamaschi, Anna,Kim, Young H.,Kwei, Kevin A.,La Choi, Yoon,Bocanegra, Melanie,Langerød, Anita,Han, Wonshik,Noh, Dong-Young,Huntsman, David G.,Jeffrey, Stefanie S.,Børresen-Dale, Anne-Lise,Pollack, J Elsevier 2008 Molecular Oncology Vol.2 No.4

<P><B>Abstract</B></P><P>Breast cancer exhibits clinical and molecular heterogeneity, where expression profiling studies have identified five major molecular subtypes. The basal-like subtype, expressing basal epithelial markers and negative for estrogen receptor (ER), progesterone receptor (PR) and HER2, is associated with higher overall levels of DNA copy number alteration (CNA), specific CNAs (like gain on chromosome 10p), and poor prognosis. Discovering the molecular genetic basis of tumor subtypes may provide new opportunities for therapy. To identify the driver oncogene on 10p associated with basal-like tumors, we analyzed genomic profiles of 172 breast carcinomas. The smallest shared region of gain spanned just seven genes at 10p13, including calcium/calmodulin-dependent protein kinase ID (<I>CAMK1D</I>), functioning in intracellular signaling but not previously linked to cancer. By microarray, <I>CAMK1D</I> was overexpressed when amplified, and by immunohistochemistry exhibited elevated expression in invasive carcinomas compared to carcinoma <I>in situ</I>. Engineered overexpression of CAMK1D in non-tumorigenic breast epithelial cells led to increased cell proliferation, and molecular and phenotypic alterations indicative of epithelial–mesenchymal transition (EMT), including loss of cell–cell adhesions and increased cell migration and invasion. Our findings identify <I>CAMK1D</I> as a novel amplified oncogene linked to EMT in breast cancer, and as a potential therapeutic target with particular relevance to clinically unfavorable basal-like tumors.</P>

Air–Liquid Interfacial Self-Assembly of Conjugated Block Copolymers into Ordered Nanowire Arrays

Cativo, Ma. Helen M.,Kim, David K.,Riggleman, Robert A.,Yager, Kevin G.,Nonnenmann, Stephen S.,Chao, Huikuan,Bonnell, Dawn A.,Black, Charles T.,Kagan, Cherie R.,Park, So-Jung American Chemical Society 2014 ACS NANO Vol.8 No.12

<P>The ability to control the molecular packing and nanoscale morphology of conjugated polymers is important for many of their applications. Here, we report the fabrication of well-ordered nanoarrays of conjugated polymers, based on the self-assembly of conjugated block copolymers at the air–liquid interface. We demonstrate that the self-assembly of poly(3-hexylthiophene)-<I>block</I>-poly(ethylene glycol) (P3HT-<I>b</I>-PEG) at the air–water interface leads to large-area free-standing films of well-aligned P3HT nanowires. Block copolymers with high P3HT contents (82–91%) formed well-ordered nanoarrays at the interface. The fluidic nature of the interface, block copolymer architecture, and rigid nature of P3HT were necessary for the formation of well-ordered nanostructures. The free-standing films formed at the interface can be readily transferred to arbitrary solid substrates. The P3HT-<I>b</I>-PEG films are integrated in field-effect transistors and show orders of magnitude higher charge carrier mobility than spin-cast films, demonstrating that the air–liquid interfacial self-assembly is an effective thin film fabrication tool for conjugated block copolymers.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2014/ancac3.2014.8.issue-12/nn505871b/production/images/medium/nn-2014-05871b_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn505871b'>ACS Electronic Supporting Info</A></P>

Concurrent Isolation of 3 Distinct Cardiac Stem Cell Populations From a Single Human Heart Biopsy

Monsanto, Megan M.,White, Kevin S.,Kim, Taeyong,Wang, Bingyan J.,Fisher, Kristina,Ilves, Kelli,Khalafalla, Farid G.,Casillas, Alexandria,Broughton, Kathleen,Mohsin, Sadia,Dembitsky, Walter P.,Sussman, Grune & Stratton 2017 Circulation research Vol.121 No.2

<P><B><U>Rationale:</U></B></P><P>The relative actions and synergism between distinct myocardial-derived stem cell populations remain obscure. Ongoing debates on optimal cell population(s) for treatment of heart failure prompted implementation of a protocol for isolation of multiple stem cell populations from a single myocardial tissue sample to develop new insights for achieving myocardial regeneration.</P><P><B><U>Objective:</U></B></P><P>Establish a robust cardiac stem cell isolation and culture protocol to consistently generate 3 distinct stem cell populations from a single human heart biopsy.</P><P><B><U>Methods and Results:</U></B></P><P>Isolation of 3 endogenous cardiac stem cell populations was performed from human heart samples routinely discarded during implantation of a left ventricular assist device. Tissue explants were mechanically minced into 1 mm<SUP>3</SUP> pieces to minimize time exposure to collagenase digestion and preserve cell viability. Centrifugation removes large cardiomyocytes and tissue debris producing a single cell suspension that is sorted using magnetic-activated cell sorting technology. Initial sorting is based on tyrosine-protein kinase Kit (c-Kit) expression that enriches for 2 c-Kit<SUP>+</SUP> cell populations yielding a mixture of cardiac progenitor cells and endothelial progenitor cells. Flowthrough c-Kit<SUP>−</SUP> mesenchymal stem cells are positively selected by surface expression of markers CD90 and CD105. After 1 week of culture, the c-Kit<SUP>+</SUP> population is further enriched by selection for a CD133<SUP>+</SUP> endothelial progenitor cell population. Persistence of respective cell surface markers in vitro is confirmed both by flow cytometry and immunocytochemistry.</P><P><B><U>Conclusions:</U></B></P><P>Three distinct cardiac cell populations with individualized phenotypic properties consistent with cardiac progenitor cells, endothelial progenitor cells, and mesenchymal stem cells can be successfully concurrently isolated and expanded from a single tissue sample derived from human heart failure patients.</P>

Biohybrid Swimmers Developed from Human Stem Cell-Derived Cardiomyocytes

Keel Yong LEE,Sung-Jin PARK,David G. MATTHEWS,Sean L. KIM,Carlos Antonio MARQUEZ,John F. ZIMMERMAN,Herdeline Ann M. ARDOnA,Andre G. KLEBER,George V. LAUDER,Kevin Kit PARKER 한국생물공학회 2022 한국생물공학회 학술대회 Vol.2022 No.9

도시 강우 유출수를 처리하는 침투도랑의 영양물질 처리 메커니즘 분석

( Kimberly Ann Yano ),( Nash Jett D. G. Reyes ),( Franz Kevin Geronimo ),이유경 ( Yookyung Lee ),김이형 ( Lee Hyung Kim ) 한국물환경학회 2020 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2020 No.-

Stormwater runoff contains pollutants such as total suspended solids (TSS), nutrients and heavy metals that can cause harmful effects to the environment. Infiltration trenches (IT) are low impact development (LID) facilities that treat and reduce the volume of stormwater runoff through filtration, sorption processes and soil microbial activities. This study assessed the performance of an IT in treating nitrogen and phosphorus in stormwater runoff and to determine the characteristics and patterns of nutrient transport in an urban catchment area. Water samples from 46 monitored events from May 2009 to September 2019 were analyzed using standard methods for the examination of water and wastewater treatment. Primary hydrologic data were obtained from the Korea Meteorological Administration. The concentrations of total nitrogen (TN) and total phosphorus (TP) on stormwater runoff ranged from 1.7 to 21.2 mg/L and 0.16 to 6.6 mg/L, respectively. Organic forms of nutrients were dominant in urban stormwater runoff and constituted to 61% and 90% of the TN and TP forms, respectively. Greater rainfall intensities resulted to a decreased TN and TP removal efficiency. For a rainfall intensity of 11mm/hr, the recorded removal efficiency for TN and TP only amounted to 34% and 55%, respectively. Low rainfall intensities (<1mm/hr) resulted to 100% removal efficiency. Increasing rainfall depth and intensity resulted to a lower pollutant removal due to the increase in hydraulic loading rate. Filtration, adsorption and sedimentation mechanisms incorporated in the design of IT were found to be the main factors that affected the removal of nutrients within IT. Generally, the IT was capable of reducing nutrient concentrations in urban stormwater runoff. Moreover, hydraulic and hydrologic can greatly influence the performance of IT.

도시 강우 유출수를 처리하는 침투도랑의 영양물질 처리 메커니즘 분석

( Kimberly Ann Yano ),( Nash Jett D. G. Reyes ),( Franz Kevin Geronimo ),이유경 ( Yookyung Lee ),김이형 ( Lee Hyung Kim ) 한국물환경학회 2020 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2020 No.-

Stormwater runoff contains pollutants such as total suspended solids (TSS), nutrients and heavy metals that can cause harmful effects to the environment. Infiltration trenches (IT) are low impact development (LID) facilities that treat and reduce the volume of stormwater runoff through filtration, sorption processes and soil microbial activities. This study assessed the performance of an IT in treating nitrogen and phosphorus in stormwater runoff and to determine the characteristics and patterns of nutrient transport in an urban catchment area. Water samples from 46 monitored events from May 2009 to September 2019 were analyzed using standard methods for the examination of water and wastewater treatment. Primary hydrologic data were obtained from the Korea Meteorological Administration. The concentrations of total nitrogen (TN) and total phosphorus (TP) on stormwater runoff ranged from 1.7 to 21.2 mg/L and 0.16 to 6.6 mg/L, respectively. Organic forms of nutrients were dominant in urban stormwater runoff and constituted to 61% and 90% of the TN and TP forms, respectively. Greater rainfall intensities resulted to a decreased TN and TP removal efficiency. For a rainfall intensity of 11mm/hr, the recorded removal efficiency for TN and TP only amounted to 34% and 55%, respectively. Low rainfall intensities (<1mm/hr) resulted to 100% removal efficiency. Increasing rainfall depth and intensity resulted to a lower pollutant removal due to the increase in hydraulic loading rate. Filtration, adsorption and sedimentation mechanisms incorporated in the design of IT were found to be the main factors that affected the removal of nutrients within IT. Generally, the IT was capable of reducing nutrient concentrations in urban stormwater runoff. Moreover, hydraulic and hydrologic can greatly influence the performance of IT.

도시 강우 유출수를 처리하는 침투도랑의 영양물질 처리 메커니즘 분석

( Kimberly Ann Yano ),( Nash Jett D. G. Reyes ),( Franz Kevin Geronimo ),이유경 ( Yookyung Lee ),김이형 ( Lee Hyung Kim ) 한국물환경학회 2020 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2020 No.-

Stormwater runoff contains pollutants such as total suspended solids (TSS), nutrients and heavy metals that can cause harmful effects to the environment. Infiltration trenches (IT) are low impact development (LID) facilities that treat and reduce the volume of stormwater runoff through filtration, sorption processes and soil microbial activities. This study assessed the performance of an IT in treating nitrogen and phosphorus in stormwater runoff and to determine the characteristics and patterns of nutrient transport in an urban catchment area. Water samples from 46 monitored events from May 2009 to September 2019 were analyzed using standard methods for the examination of water and wastewater treatment. Primary hydrologic data were obtained from the Korea Meteorological Administration. The concentrations of total nitrogen (TN) and total phosphorus (TP) on stormwater runoff ranged from 1.7 to 21.2 mg/L and 0.16 to 6.6 mg/L, respectively. Organic forms of nutrients were dominant in urban stormwater runoff and constituted to 61% and 90% of the TN and TP forms, respectively. Greater rainfall intensities resulted to a decreased TN and TP removal efficiency. For a rainfall intensity of 11mm/hr, the recorded removal efficiency for TN and TP only amounted to 34% and 55%, respectively. Low rainfall intensities (<1mm/hr) resulted to 100% removal efficiency. Increasing rainfall depth and intensity resulted to a lower pollutant removal due to the increase in hydraulic loading rate. Filtration, adsorption and sedimentation mechanisms incorporated in the design of IT were found to be the main factors that affected the removal of nutrients within IT. Generally, the IT was capable of reducing nutrient concentrations in urban stormwater runoff. Moreover, hydraulic and hydrologic can greatly influence the performance of IT.

Organic Thin‐Film Transistors: Simultaneous Modification of Bottom‐Contact Electrode and Dielectric Surfaces for Organic Thin‐Film Transistors Through Single‐Component Spin‐Cast Monolayers (Adv. Funct. Mater. 8/2011)

Acton, Orb,Dubey, Manish,Weidner, Tobias,O’Malley, Kevin M.,Kim, Tae‐,Wook,Ting, Guy G.,Hutchins, Daniel,Baio, J. E.,Lovejoy, Tracy C.,Gage, Alexander H.,Castner, David G.,Ma, Hong,Jen, Alex K.& WILEY‐VCH Verlag 2011 Advanced functional materials Vol.21 No.8

<P><B>Abstract</B></P><P>An efficient process is developed by spin‐coating a single‐component, self‐assembled monolayer (SAM) to simultaneously modify the bottom‐contact electrode and dielectric surfaces of organic thin‐film transistors (OTFTs). This effi cient interface modifi cation is achieved using <I>n</I>‐alkyl phosphonic acid based SAMs to prime silver bottom‐contacts and hafnium oxide (HfO<SUB>2</SUB>) dielectrics in low‐voltage OTFTs. Surface characterization using near edge X‐ray absorption fi ne structure (NEXAFS) spectroscopy, X‐ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, atomic force microscopy (AFM), and spectroscopic ellipsometry suggest this process yields structurally well‐defi ned phosphonate SAMs on both metal and oxide surfaces. Rational selection of the alkyl length of the SAM leads to greatly enhanced performance for both <I>n</I>‐channel (C<SUB>60</SUB>) and p‐channel (pentacene) based OTFTs. Specifi cally, SAMs of <I>n</I>‐octylphos‐phonic acid (OPA) provide both low‐contact resistance at the bottom‐contact electrodes and excellent interfacial properties for compact semiconductor grain growth with high carrier mobilities. OTFTs based on OPA modifi ed silver electrode/HfO<SUB>2</SUB> dielectric bottom‐contact structures can be operated using < 3V with low contact resistance (down to 700 Ohm‐cm), low subthreshold swing (as low as 75 mV dec<SUP>−1</SUP>), high on/off current ratios of 107, and charge carrier mobilities as high as 4.6 and 0.8 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, for C60 and pentacene, respectively. These results demonstrate that this is a simple and efficient process for improving the performance of bottom‐contact OTFTs.</P>