Roles of Islet Toll-Like Receptors in Pig to Mouse Islet Xenotransplantation

Ro, Han,Lee, Eun Won,Hong, Joo Ho,Han, Kyu Hyun,Yeom, Hye-Jung,Kim, Hwa Jung,Kim, Myung-Gyu,Jung, Hye Seung,Oh, Kook-Hwan,Park, Kyong Soo,Ahn, Curie,Yang, Jaeseok SAGE Publications 2013 Cell transplantation Vol.22 No.9

<P>Although innate immunity plays important roles in xenograft rejection, there have been few studies on the role of toll-like receptors (TLRs) in xenotransplantation. Furthermore, most studies focused on the recipient's TLRs. Therefore, we investigated whether TLRs in porcine islets can contribute to islet xenograft rejection. Adult porcine islets were isolated and stimulated by polyinosinic/polycytidylic acid (poly I:C) or lipopolysaccharide (LPS). Both poly I:C and LPS stimulation in porcine islets induced expression of chemokines (RANTES, MCP-1, IP-10, and IL-8), cytokines (IL-6 and type I interferons), and adhesion molecules (VCAM-1 and ICAM-1). Porcine islet supernatants stimulated by TLR agonists induced chemotaxis of human leukocytes. They also induced procoagulant activation (tissue factor and fgl-2). However, TLR stimulation did not influence insulin secretion. When porcine MyD88 was knocked down using shRNA lentivirus, TLR-mediated induction of proinflammatory mediators and procoagulants was attenuated. When LPS was injected to MyD88 or TLR4 knockout mice after porcine islet transplantation, LPS stimulation on donor islets interfered with islet xenograft tolerance induction by anti-CD154 antibodies. Inflammatory cell infiltration and expression of proinflammatory chemokines and cytokines in islet xenografts also increased. In conclusion, TLR activation in porcine islets induced both a proinflammatory and procoagulant response and thereby contributed to xenograft rejection.</P>

Impact of Tacrolimus Intraindividual Variability and CYP3A5 Genetic Polymorphism on Acute Rejection in Kidney Transplantation

Ro, Han,Min, Sang-Il,Yang, Jaeseok,Moon, Kyung Chul,Kim, Yon Su,Kim, Sang Joon,Ahn, Curie,Ha, Jongwon Lippincott Williams Wilkins, Inc. 2012 Therapeutic drug monitoring Vol.34 No.6

BACKGROUND:: Wide variation in tacrolimus concentrations and low tacrolimus exposure have been reported to be associated with poor renal graft outcomes in non-Asians. The CYP3A5 polymorphism is a representative genetic factor that might affect this association, together with environmental factors. We investigated whether tacrolimus variability or the mean tacrolimus trough concentration can influence kidney allograft outcomes in Asians and whether the CYP3A5 polymorphism (rs776746) can affect this relationship. METHODS:: Data from renal transplant patients between 2000 and 2010 were analyzed retrospectively. The tacrolimus intraindividual variability (IIV) and the mean tacrolimus trough concentration were calculated from the tacrolimus concentrations between 6 and 12 months after transplantation. RESULTS:: A total of 249 renal transplant patients were enrolled. The patients with higher tacrolimus IIV had shorter rejection-free survival (P = 0.002). However, there was no difference in rejection-free survival between CYP3A5 expressers and nonexpressers. The tacrolimus IIV was not associated with the CYP3A5 polymorphism. High IIV of tacrolimus was an independent risk factor of biopsy-proven acute rejection after adjusting for mean tacrolimus concentration, HLA mismatch, induction therapy, donor type, and CYP3A5 polymorphism (hazard ratio 2.655, 95% confidence interval 1.394–5.056). Interestingly, the impact of tacrolimus IIV on acute rejection was significant in CYP3A5 expressers, whereas it was not in CYP3A5 nonexpressers. CONCLUSIONS:: The IIV of tacrolimus trough concentrations had a significant impact on rejection-free survival. The effect was influenced by CYP3A5 polymorphism, although the tacrolimus variability itself was not determined by the CYP3A5 polymorphism.

Roles of Toll-Like Receptors in Allogeneic Islet Transplantation

Ro, Han,Hong, Juho,Kim, Beom Seok,Lee, Eun Won,Kim, Myung-Gyu,Han, Kyu Hyun,Yeom, Hye-Jung,Lee, Eun Mi,Jeong, Jong Cheol,Oh, Kook-Hwan,Ahn, Curie,Yang, Jaeseok Lippincott Williams Wilkins, Inc. 2012 Transplantation Vol.94 No.10

BACKGROUND: Toll-like receptors (TLRs) are involved in the rejection of solid organ allografts. However, the roles of TLRs in islets are still controversial. We investigated the roles of TLRs in donor islets together with those in recipients in allogeneic islet transplantation. METHODS: To assess the roles of TLRs in either donor islets or recipients, allogeneic islet transplantation was performed using myeloid differentiation factor 88 (MyD88)-knockout (KO), TLR4-KO, or Toll/interleukin-1 receptor domain-containing adaptor-inducing interferon-&bgr; (TRIF)-KO mice. RESULTS: Both polyriboinosinic polyribocytidylic acid and lipopolysaccharide (LPS) stimulation induced the mRNA expression of regulated and normal T cell expressed and secreted, interferon-&ggr;–inducible protein-10, monocyte chemotactic protein-1, interleukin-8, and inducible nitric oxide synthase in murine islets, whereas the induction was attenuated in TRIF-KO, interferon-&bgr; promoter stimulator-1-KO, and TLR4-KO mice. When islets from MyD88-KO, TLR4-KO, or TRIF-KO C57BL/6 mice were transplanted to BALB/c recipients, graft survival was not better than that of wild-type (WT) islets. However, the survival of the MyD88-KO islet allograft was significantly prolonged when combined with anti-CD40L. In parallel, LPS stimulation in donor islets interfered with anti-CD40L blockade-mediated long-term survival of islet allografts in TLR4-KO recipients. LPS stimulation increased the perigraft infiltration of both T cells and macrophages. Then again, when islets from WT BALB/c mice were transplanted to MyD88-KO, TRIF-KO, or WT C57BL/6 mice, there was no difference in graft survival, although some of the MyD88-KO recipients obtained long-term graft survival. However, anti-CD40L prolonged graft survival significantly in MyD88-KO recipients. The absence of MyD88 in either donors or recipients decreased the perigraft infiltration of inflammatory cells when combined with anti-CD40L. CONCLUSIONS: TLRs in both donor islets and recipients are involved in islet allograft rejection.

학생들을 위한 추천도서

Rohan Lewis Blair 한국초등영어교육학회 2009 한국초등영어교육학회회보 Vol.- No.26

Recovery of Bioavailable Calcium from Alaska Pollack (Theragra chalcogramma) Fish Backbone By-products by Pepsinolytic Hydrolysis

Rohan Karawita,Soo-Jin Heo,Bae-Jin Lee,Se-Kwon Kim,Choon Bok Song,You-Jin Jeon 한국식품영양과학회 2006 Preventive Nutrition and Food Science Vol.11 No.2

Fish backbone, a major by-product in the fish processing industry, accounts for about 15% of whole fish weight. In this study, recovery of bioavailable calcium from Alaska pollack (Theragra chalcogramma) backbone by-products using enzymatic hydrolysis was investigated. Finely ground fish backbones were hydrolyzed with two proteolytic enzymes (pepsin and protease) to obtain soluble calcium from the by-products. The pepsin digest had a higher degradation efficiency (88%) than protease. Four different concentrations of the fish backbone calcium (100, 250, 500 and 1000 ㎎/L) prepared by the pepsin digest were treated with Na₂HPO₄ at a concentration gradient (0, 1, 2, 4, 8, 10, 15 and 20 mM) to evaluate their solubility, revealing that solubilities of the fish backbone calcium were superior to those of CaCl₂ at all the calcium and Na₂HPO₄ concentrations. Among the tested concentrations the highest solubility was found in the pepsin digest containing a calcium concentration of 1000 ㎎/L. Thus, hydrolyzing with pepsin is an effective mode of recovering bioavailable calcium from Alaska pollack fish backbones.

Design of Fuzzy Logic Based Controller for Gyroscopic Inverted Pendulum System

Rohan, Ali,Rabah, Mohammed,Nam, Kang-Hyun,Kim, Sung Ho Korean Institute of Intelligent Systems 2018 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.18 No.1

Anti-rolling gyro systems (ARG) were introduced long time ago for reducing the roll motion of ships caused by the ocean waves. These systems are composed of gyroscopic stabilizer, which typically controls the roll motion by generating some counteracting roll stabilizing torque. These systems are very sensitive to the outer disturbances and require robust control mechanism to maintain the stable state. In this work, gyroscopic inverted pendulum based on gyroscopic stabilizer is considered to develop control technique for reducing the roll motion effect of the system. The gyroscopic inverted system was modeled in MATLAB/Simulink and fuzzy logic based control technique was developed. The proposed control technique was implemented and tested with the practical system. Furthermore, the performance of the proposed system is compared with a typical PD type controller. Simulation and experimental results show that the proposed system performs well and maintains a stable state under various disturbances.

Fault Detection and Diagnosis System for a Three-Phase Inverter Using a DWT-Based Artificial Neural Network

Rohan, Ali,Kim, Sung Ho Korean Institute of Intelligent Systems 2016 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.16 No.4

Inverters are considered the basic building blocks of industrial electrical drive systems that are widely used for various applications; however, the failure of electronic switches mainly affects the constancy of these inverters. For safe and reliable operation of an electrical drive system, faults in power electronic switches must be detected by an efficient system that is capable of identifying the type of faults. In this paper, an open switch fault identification technique for a three-phase inverter is presented. Single, double, and triple switching faults can be diagnosed using this method. The detection mechanism is based on stator current analysis. Discrete wavelet transform (DWT) using Daubechies is performed on the Clarke transformed (-) stator current and features are extracted from the wavelets. An artificial neural network is then used for the detection and identification of faults. To prove the feasibility of this method, a Simulink model of the DWT-based feature extraction scheme using a neural network for the proposed fault detection system in a three-phase inverter with an induction motor is briefly discussed with simulation results. The simulation results show that the designed system can detect faults quite efficiently, with the ability to differentiate between single and multiple switching faults.

Condylar jugular diverticulum: A report of 3 cases

Rohan Jagtap,Taggreed Wazzan,Matthew Hansen,Deeba Kashtwari 대한영상치의학회 2019 Imaging Science in Dentistry Vol.49 No.3

Jugular bulb diverticulum is an irregular extension of the jugular bulb into the temporal bone that may be symptomatic or asymptomatic. The jugular bulb has rarely been reported to extend into the occipital condyle; such extension is termed a condylar jugular diverticulum and is characterized as a defect in the occipital condyle contiguous with the jugular bulb. This report details 3 cases of condylar jugular diverticulum. Extension of the jugular bulb into the ipsilateral occipital condyle was noted as an incidental finding on cone-beam computed tomographic (CBCT) images of 3 patients. All 3 patients were asymptomatic, and this finding was unrelated to the initial area of interest. CBCT use is becoming ubiquitous in dentistry, as it allows 3-dimensional evaluation, unlike conventional radiography. Proper interpretation of the entire CBCT is essential, and recognition of the indicators of condylar jugular diverticulum may prevent misdiagnosis of this rare entity.

An Integrated Fault Detection and Identification System for Permanent Magnet Synchronous Motor in Electric Vehicles

Rohan, Ali,Rabah, Mohammed,Kim, Sung Ho Korean Institute of Intelligent Systems 2018 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.18 No.1

This paper proposes an efficient and integrated fault detection and identification system for power converters and permanent magnet synchronous motor in electric vehicles. Switching faults of power converters (single, double and triple switching faults), electrical and mechanical faults of the permanent magnet synchronous motor (bearing fault, stator electrical faults) are considered. Fault detection is done using Clarke transformed (${\alpha}-{\beta}$) three-phase current analysis. Features are extracted from the current signals and artificial neural network (ANN) is used for the fault identification. Using motor current signature analysis and by selecting simple and suitable features, the system can detect and distinguish between overall faults of power converters and permanent magnet synchronous motor in an electric vehicle; it requires no complex calculations. The proposed system is designed in MATLAB/Simulink. The system is tested under different fault scenarios and performance is evaluated. The simulation results have proved that the proposed system can detect and identify overall faults of power converters and permanent magnet synchronous motor easily and effectively with no need for complex calculations and techniques.

A Case of Bilateral Occipital Lobe Infarcts Following Indian Tree Viper Bite

Rohan Mahale,Anish Mehta,Mahendra Javali,R. Srinivasa 대한뇌졸중학회 2014 Journal of stroke Vol.16 No.3