59 research outputs found
Avian influenza viruses in Korean live poultry markets and their pathogenic potential
AbstractWe surveyed live-poultry markets in Korea in 2003 and isolated 9 H9N2, 6 H3N2, and 1 H6N1 influenza viruses. Antigenic and phylogenetic analyses showed that all 9 H9N2 isolates were of A/Chicken/Korea/25232-96006/96-like lineage (which caused disease in chickens in Korea in 1996) but were different from H9N2 viruses of southeastern China. They had at least 4 genotypes and replicated in chickens but not in mice. The H3N2 and H6N1 viruses were new to Korea and were probably reassortants of avian influenza viruses from southeastern China and recent Korean H9N2 viruses. All 8 segments of the H3N2 viruses formed a single phylogenetic cluster with 99.1 to 100% homology. The H3N2 viruses replicated in chickens and mice without preadaptation, but the H6N1 virus did not. Our results show an increasingly diverse pool of avian influenza viruses in Korea that are potential pandemic influenza agents
Highly Pathogenic Avian Influenza Virus (H5N1) in Domestic Poultry and Relationship with Migratory Birds, South Korea
During the 2006–2007 winter season in South Korea, several outbreaks of highly pathogenic avian influenza virus (H5N1) were confirmed among domestic poultry and in migratory bird habitats. Phylogenetic analysis showed that all isolates were closely related and that all belong to the A/bar-headed goose/Qinghai/5/2005–like lineage rather than the A/chicken/Korea/ES/2003–like lineage
Granulocyte Colony Stimulating Factor Attenuates Hyperoxia-Induced Lung Injury by Down-Modulating Inflammatory Responses in Neonatal Rats
Clinical Characteristics of a Nationwide Hospital-based Registry of Mild-to-Moderate Alzheimer's Disease Patients in Korea: A CREDOS (Clinical Research Center for Dementia of South Korea) Study
With rapid population aging, the socioeconomic burden caused by dementia care is snowballing. Although a few community-based studies of Alzheimer's disease (AD) have been performed in Korea, there has never been a nationwide hospital-based study thereof. We aimed to identify the demographics and clinical characteristics of mild-to-moderate AD patients from the Clinical Research Center for Dementia of Korea (CREDOS) registry. A total of 1,786 patients were consecutively included from September 2005 to June 2010. Each patient underwent comprehensive neurological examination, interview for caregivers, laboratory investigations, neuropsychological tests, and brain MRI. The mean age was 74.0 yr and the female percentage 67.0%. The mean period of education was 7.1 yr and the frequency of early-onset AD (< 65 yr old) was 18.8%. Among the vascular risk factors, hypertension (48.9%) and diabetes mellitus (22.3%) were the most frequent. The mean score of the Korean version of Mini-Mental State Examination (K-MMSE) was 19.2 and the mean sum of box scores of Clinical Dementia Rating (CDR-SB) 5.1. Based on the well-structured, nationwide, and hospital-based registry, this study provides the unique clinical characteristics of AD and emphasizes the importance of vascular factors in AD in Korea
Prediction of cognitive impairment via deep learning trained with multi-center neuropsychological test data
Background
Neuropsychological tests (NPTs) are important tools for informing diagnoses of cognitive impairment (CI). However, interpreting NPTs requires specialists and is thus time-consuming. To streamline the application of NPTs in clinical settings, we developed and evaluated the accuracy of a machine learning algorithm using multi-center NPT data.
Methods
Multi-center data were obtained from 14,926 formal neuropsychological assessments (Seoul Neuropsychological Screening Battery), which were classified into normal cognition (NC), mild cognitive impairment (MCI) and Alzheimers disease dementia (ADD). We trained a machine learning model with artificial neural network algorithm using TensorFlow (https://www.tensorflow.org) to distinguish cognitive state with the 46-variable data and measured prediction accuracies from 10 randomly selected datasets. The features of the NPT were listed in order of their contribution to the outcome using Recursive Feature Elimination.
Results
The ten times mean accuracies of identifying CI (MCI and ADD) achieved by 96.66 ± 0.52% of the balanced dataset and 97.23 ± 0.32% of the clinic-based dataset, and the accuracies for predicting cognitive states (NC, MCI or ADD) were 95.49 ± 0.53 and 96.34 ± 1.03%. The sensitivity to the detection CI and MCI in the balanced dataset were 96.0 and 96.0%, and the specificity were 96.8 and 97.4%, respectively. The time orientation and 3-word recall score of MMSE were highly ranked features in predicting CI and cognitive state. The twelve features reduced from 46 variable of NPTs with age and education had contributed to more than 90% accuracy in predicting cognitive impairment.
Conclusions
The machine learning algorithm for NPTs has suggested potential use as a reference in differentiating cognitive impairment in the clinical setting.The publication costs, design of the study, data management and writing the manuscript for this article were supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2017S1A6A3A01078538), Korea Ministry of Health & Welfare, and from
the Original Technology Research Program for Brain Science through the National Research Foundation of Korea funded by the Korean Government (MSIP; No. 2014M3C7A1064752)
Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza
The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections
Prion-like Propagation of α-Synuclein Is Regulated by the FcγRIIB-SHP-1/2 Signaling Pathway in Neurons
Summary: Recent evidence of prion-like propagation of α-synuclein (α-syn) into neighboring neurons set up a paradigm to elucidate the mechanism of progression of Parkinson’s disease (PD) and to develop therapeutic strategies. Here, we show that FcγRIIB expressed in neurons functions as a receptor for α-syn fibrils and mediates cell-to-cell transmission of α-syn. SHP-1 and 2 are activated downstream by α-syn fibrils through FcγRIIB and play an important role in cell-to-cell transmission of α-syn. Also, taking advantage of a co-culture system, we show that cell-to-cell transmission of α-syn induces intracellular Lewy body-like inclusion body formation and that the FcγRIIB/SHP-1/2 signaling pathway is involved in it. Therefore, the FcγRIIB-SHP-1/-2 signaling pathway may be a therapeutic target for the progression of PD. The in vitro system is an efficient tool for further high-throughput screening that can be used for developing a therapeutic intervention in PD. : Prion-like propagation of α-synuclein (α-syn) may contribute to the progression of Parkinson’s disease. Choi et al. demonstrate that FcγRIIB functions as a receptor for α-syn fibrils and that the FcγRIIB-SHP-1/2 signaling pathway mediates cell-to-cell transmission of α-syn. Blocking this signaling pathway attenuates transmission, suppressing Lewy body-like inclusion body formation. Keywords: α-synuclein, cell-to-cell transmission, FcγRIIB, SHP-1, SHP-
Identification of Porphyromonas gingivalis lipopolysaccharide-binding proteins in human saliva
Porphyromonas gingivalis causes periodontal diseases and its lipopolysaccharide (LPS) is considered as a major virulence factor responsible for pathogenesis. Since initial recognition of P. gingivalis LPS (Pg.LPS) in the oral cavity might be crucial for the host response, we identified Pg.LPS-binding proteins (Pg.LPS-BPs) using Pg.LPS-immobilized beads and a high-resolution mass spectrometry. LPS purified from P. gingivalis was conjugated onto N-hydroxysuccinimidyl-Sepharose (R) 4 Fast Flow beads. Notably, Pg.LPS-conjugated beads could stimulate Toll-like receptor 2 (TLR2) as determined by a TLR2-depdendent reporter expression system using CHO/CD14/TLR2. In addition, the Pg.LPS-conjugated beads induced the production of inflammatory mediators such as nitric oxide and interferon-gamma-inducible protein-10 in the macrophage cell-line, RAW 264.7. These results imply that Pg.LPS retained its immunological properties during the conjugation process. Then, the Pg.LPS-conjugated beads were mixed with a pool of saliva obtained from nine human subjects to capture Pg.LPS-BPs and molecular identities were determined by LTQ-Orbitrap hybrid fourier transform mass spectrometry. Pg.LPS-BPs captured at high frequencies included alpha-amylase, cystatin, prolactin-inducible protein, lysozyme C, immunoglobulin components, serum albumin, lipocalin-1, and submaxillary gland androgen-regulated protein 3B. These proteins are known to be involved in bacterial adhesion and colonization, anti-microbial functions or modulation of immune responses. (C) 2011 Elsevier Ltd. All rights reserved.This research was supported by the grants from the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (MEST) (Nos. 2009-0086835, 2010-0029116, and 20110001030), Republic of Korea.
A case of pemphigus vulgaris associated with ulcerative colitis
Pemphigus vulgaris is an autoimmune bullous disorder characterized by the production of autoantibodies against the intercellular space of the epithelium. It has rarely been reported in association with inflammatory bowel disease. Ulcerative colitis is one of the forms of inflammatory bowel disease. A 62-year-old woman who had been treated for ulcerative colitis for 16 years developed pruritic bullae on the skin of her face and body. Histological findings and direct immunofluorescence examination of the skin showed pemphigus vulgaris. She was treated with systemic steroids, mesalazine, and azathioprine. Her cutaneous lesions have remained in remission and her ulcerative colitis has remained well-controlled. The relationship between pemphigus vulgaris and ulcerative colitis is unclear. An autoimmune response has been suspected in the pathogenesis of ulcerative colitis. Pemphigus vulgaris is also associated with an autoimmune mechanism. To our knowledge, this is the first case of ulcerative colitis associated with pemphigus vulgaris reported in Korea. The association may be causal
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