Direct and Indirect Evidence of Effects of Bacteroides spp. on Obesity and Inflammation.

Metabolic disorders present a significant public health challenge globally. The intricate relationship between the gut microbiome, particularly Bacteroides spp. (BAC), and obesity, including their specific metabolic functions, remains partly unresolved. This review consolidates current research on BAC's role in obesity and lipid metabolism, with three objectives: (1) To summarize the gut microbiota's impact on obesity; (2) To assess BAC's efficacy in obesity intervention; (3) To explore BAC's mechanisms in obesity and lipid metabolism management. This review critically examines the role of BAC in obesity, integrating findings from clinical and preclinical studies. We highlight the changes in BAC diversity and concentration following successful obesity treatment and discuss the notable differences in BAC characteristics among individuals with varying obesity levels. Furthermore, we review recent preclinical studies demonstrating the potential of BAC in ameliorating obesity and related inflammatory conditions, providing detailed insights into the methodologies of these in vivo experiments. Additionally, certain BAC-derived metabolites have been shown to be involved in the regulation of host lipid metabolism-related pathways. The enhanced TNF production by dendritic cells following BAC administration, in response to LPS, also positions BAC as a potential adjunctive therapy in obesity management.

Synthesis and biological evaluation of novel purinyl quinazolinone derivatives as PI3Kδ-specific inhibitors for the treatment of hematologic malignancies.

Phosphatidylinositol 3-kinases (PI3Ks) mediate intracellular signal transduction. Aberrant PI3K signaling is associated with oncogenesis and disease progression in solid tumors and hematologic malignancies. Idelalisib (1), a first-in-class PI3Kδ inhibitor for the treatment of hematologic malignancies, was developed, but its sales were limited by black box warnings due to unexpected adverse effects. Therefore, to overcome these adverse events, various quinazolinone derivatives were synthesized and evaluated in vitro based on their inhibitory activity against the PI3K enzyme and the viability of cell lines such as MOLT and SUDHL. Among them, 6f (IC50 = 0.39 nM) and 6m (IC50 = 0.09 nM) showed excellent enzyme activity, and 6m displayed an approximately four-fold higher selectivity for PI3Kγ/δ compared with Idelalisib (1). Furthermore, in vivo PK experiments with 6f and 6m revealed that 6f (AUClast = 81.04 h*ng/mL, Cmax = 18.34 ng/mL, Tmax = 0.5 h, t1/2 = 10.2 h in 1 mpk dose) had improved PK compared with 1. Finally, further experiments will be conducted with 6f selected as a candidate, and the potential for it to be developed as a treatment with good efficacy for hematologic malignancies will be determined.

Pharmacoacupuncture for the Treatment of Frozen Shoulder: protocol for a systematic review and meta-analysis.

Objectives: Frozen shoulder (FS) is one of the most challenging shoulder disorders for patients and clinicians. Its symptoms mainly include any combination of stiffness, nocturnal pain, and limitation of active and passive glenohumeral joint movement. Conventional treatment options for FS are physical therapy, nonsteroidal anti-inflammatory drugs, injection therapy, and arthroscopic capsular release, but adverse and limited effects continue to present problems. As a result, pharmacoacupuncture (PA) is getting attention as an alternative therapy for patients with FS. PA is a new form of acupuncture treatment in traditional Korean medicine (TKM) that is mainly used for musculoskeletal diseases. It has similarity and specificity compared to corticosteroid injection and hydrodilatation, making it a potential alternative injection therapy for FS. However, no systematic reviews investigating the utilization of PA for FS have been published. Therefore, this review aims to standardize the clinical use of PA for FS and validate its therapeutic effect. Methods: The protocol was registered in Prospero (CRD42023445708) on 18 July 2023. Until Aug. 31, 2023, seven electronic databases will be searched for randomized controlled trials of PA for FS. Authors will be contacted, and manual searches will also be performed. Two reviewers will independently screen and collect data from retrieved articles according to predefined criteria. The primary outcome will be pain intensity, and secondary outcomes will be effective rate, Constant-Murley Score, Shoulder Pain and Disability Index, range of motion, quality of life, and adverse events. Bias and quality of the included trials will be assessed using the Cochrane handbook's risk-of-bias tool for randomized trials. Meta analyses will be conducted using Review Manager V.5.3 software. GRADE will be used to evaluate the level of evidence for each outcome. Results: This systematic review and meta-analysis will be conducted following PRISMA statement. The results will be published in a peer-reviewed journal. Conclusion: This review will provide scientific evidence to support health insurance policy as well as the standardization of PA in clinical practice.

Solar-Powered AEM Electrolyzer via PGM-Free (Oxy)hydroxide Anode with Solar to Hydrogen Conversion Efficiency of 12.44.

Water electrolyzers powered by renewable energy are emerging as clean and sustainable technology for producing hydrogen without carbon emissions. Specifically, anion exchange membrane (AEM) electrolyzers utilizing non-platinum group metal (non-PGM) catalysts have garnered attention as a cost-effective method for hydrogen production, especially when integrated with solar cells. Nonetheless, the progress of such integrated systems is hindered by inadequate water electrolysis efficiency, primarily caused by poor oxygen evolution reaction (OER) electrodes. To address this issue, a NiFeCo─OOH has developed as an OER electrocatalyst and successfully demonstrated its efficacy in an AEM electrolyzer, which is powered by renewable electricity and integrated with a silicon solar cell.

Effect of immersive virtual mirror visual feedback on Mu suppression and coherence in motor and parietal cortex in stroke.

We investigated the activation pattern of the motor cortex (M1) and parietal cortex during immersive virtual reality (VR)-based mirror visual feedback (MVF) of the upper limb in 14 patients with chronic stroke and severe upper limb hemiparesis and in 21 healthy controls. Participants performed wrist extension with unaffected wrists (dominant side in controls). In the MVF condition, movement of the affected hand was synchronized with that of the unaffected hand. In the no-MVF condition, only the movement of unaffected hand was shown. Mu suppression in bilateral M1 and parietal cortex and mu coherence were analyzed. In patients with stroke, MVF induced significant mu suppression in both the ipsilesional M1 and parietal lobes (p = 0.006 and p = 0.009, respectively), while mu suppression was observed in the bilateral M1 (p = 0.003 for ipsilesional and p = 0.041 for contralesional M1, respectively) and contralesional parietal lobes in the controls (p = 0.036). The ipsilesional mu coherence between the M1 and parietal cortex in patients with stroke was stronger than controls, regardless of MVF condition (p < 0.001), while mu coherence between interhemispheric M1 cortices was significantly weaker in patients with stroke (p = 0.032). Our findings provide evidence of the neural mechanism of MVF using immersive VR in patients with stroke.

A Clinical Study on the Relationship Among Insomnia, Tongue Diagnosis, and Oral Microbiome.

Currently, there is a lack of adequate methods to assess insomnia objectively. This study addresses the usefulness of tongue features and oral microbial profile as a potential diagnostic biomarker of insomnia. One hundred insomniac patients and 20 healthy control subjects were selected. Their demographic and clinical characteristics, as well as the tongue diagnostic indices and oral microbial profile, were examined. Compared to the control group, insomniac patients showed a higher abnormal low-frequency/high-frequency (LF/HF) ratio. In tongue diagnosis, the indices related to lightness of tongue body and tongue coating were higher in the insomniac group vs. the control group. Furthermore, linear discriminant analysis (LDA) of oral microbial population revealed that the relative abundances of Clostridia, Veillonella, Bacillus and Lachnospiraceae were significantly higher in the insomniac patients than the control group. Additionally, the tongue features of the insomniac group exhibited that the non-coating group had a poor sleep condition compared to the thick-coating group, although the difference was insignificant. On the other hand, the oral microbial communities of the insomniac patients revealed greater alpha and beta diversities in the non-coating group vs. the thick-coating group. The alpha and beta diversities were higher in orotype1 than orotype2. Collectively, this study highlighted that the lightness of tongue body and tongue coating as well as oral microbial profiles of SR1, Actinobacteria, Clostridia and Lachnospiraceae_unclassified could be considered potential biomarkers of insomnia.

A survey of the clinical practice followed by Korean medicine doctors for scoliosis: Preliminary data for clinical practice guidelines.

Scoliosis is a spinal disease in which the Cobb angle is >10°. Scoliosis treatment can be surgical or conservative, and clinical practice guidelines (CPGs) for conservative treatments have been updated since 2006. There have been several articles regarding the efficacy and safety of Korean medicine (KM) in treating scoliosis, but there are no CPGs. Our study investigated the current clinical practice using a survey for the future establishment of KM-CPGs. The survey mainly comprised clinical practice status, diagnosis, treatment, progress and prognosis, and perception of KM on scoliosis, with reference to existing surveys of other musculoskeletal disorders and scoliosis-related articles. A web-based survey was conducted from February 16, 2021 to February 28, 2021. We found that 60% of KM doctors (KMDs) respondents treated patients with scoliosis, and they valued radiographical measurements and scoliosis-related factors in the diagnosis. KMDs used multiple KM treatments, including acupuncture, Chuna, cupping, pharmacopuncture, and herbal medicine, and they emphasized the importance of KM more in nonstructural scoliosis than in structural scoliosis. Although the perception of the prognosis of scoliosis was in agreement with that suggested by previous guidelines, KMDs showed outstanding focus on reduction of symptoms of scoliosis and improvement of quality of life. Despite some limitations, including low participation and the need for consulting other medical practitioners, our study may be helpful for the development of KM-CPGs because it is the first to analyze the perceptions of KMDs on scoliosis and to collect preliminary data that are of significance for preparing clinical guidelines.

Solanum melongena L. Extract Protects Retinal Pigment Epithelial Cells from Blue Light-Induced Phototoxicity in In Vitro and In Vivo Models.

N-retinylidene-N-retinylethanolamine (A2E) accumulation in the retina is a prominent marker of retinal degenerative diseases. Blue light exposure is considered as an important factor contributing to dry age-related macular degeneration (AMD). Eggplant and its constituents have been shown to confer health benefits, but their therapeutic effects on dry AMD remain incompletely understood. In this study, we showed that an extract of Solanum melongena L. (EPX) protected A2E-laden ARPE-19 cells against blue light-induced cell death via attenuating reactive oxygen species. Transcriptomic analysis demonstrated that blue light modulated the expression of genes associated with stress response, inflammation, and cell death, and EPX suppressed the inflammatory pathway induced by blue light in A2E-laden ARPE-19 cells by inhibiting the nuclear translocation of nuclear factor kappa B and transcription of pro-inflammatory genes (CXCL8 and IL1B). The degradation of intracellular A2E was considered the major mechanism underlying the protective effect of EPX. Moreover, chlorogenic acid isolated from EPX exerted protective effects against blue light-induced cell damage in A2E-laden ARPE-19 cells. In vivo, EPX administration in BALB/c mice reduced the fundus damage and degeneration of the retinal layer in a blue light-induced retinal damage model. Collectively, our findings suggest the potential role of Solanum melongena L. extract for AMD treatment.

The effectiveness and safety of Chuna manual therapy on scoliosis: A protocol for systematic review and meta-analysis.

BACKGROUND: Scoliosis is a spinal deformity and is diagnosed as Cobb angle being greater than 10°. Because it is accompanied with structural dysfunction, it can cause pain, worsen the patient's general health and quality of life. The prevalence of scoliosis has been increasing and many treatments, including surgical treatment and conservative treatment, such as observation, bracing, physiotherapy, and Chuna manual therapy (CMT), have been suggested. CMT is a manual therapy in Korean medicine that provides effective stimulation to the patient's body structure to treat structural dysfunction. After Korean national health insurance's coverage of CMT in 2019, the application of CMT for scoliosis has increased, and many studies have been reported. There have been attempts to elucidate the effectiveness of CMT on scoliosis; however, its effectiveness still remains unconfirmed. Therefore, the aim of this study is to evaluate the effectiveness and safety of CMT on scoliosis. METHODS: The published randomized controlled trials that evaluated the effectiveness and safety of CMT for scoliosis will be searched for in multiple electronic databases without the limitation of country and language. Data on characteristics of studies, interventions, comparators, outcome measures, results, and information for assessment of study quality will be extracted. The primary outcome will be the Cobb angle and the secondary outcomes will be the scales of pain, function, quality of life and disability, and adverse events. Data synthesis and analysis will be conducted using the Review Manager software for Windows (RevMan ver. 5.3.; Copenhagen; The Nordic Cochrane Center, The Cochrane Collaboration, 2014). Subgroup analysis to identify the differences between different CMT maneuvers will also be performed. For risk of bias assessment, the "risk of bias" tool from Cochrane Collaboration will be used. RESULTS: This study will present the clinical evidence on the effectiveness and safety of CMT on scoliosis. CONCLUSION: This study will propose useful evidence for treatment, further research, and health policies in the future.

Evolutionarily informed machine learning enhances the power of predictive gene-to-phenotype relationships.

Inferring phenotypic outcomes from genomic features is both a promise and challenge for systems biology. Using gene expression data to predict phenotypic outcomes, and functionally validating the genes with predictive powers are two challenges we address in this study. We applied an evolutionarily informed machine learning approach to predict phenotypes based on transcriptome responses shared both within and across species. Specifically, we exploited the phenotypic diversity in nitrogen use efficiency and evolutionarily conserved transcriptome responses to nitrogen treatments across Arabidopsis accessions and maize varieties. We demonstrate that using evolutionarily conserved nitrogen responsive genes is a biologically principled approach to reduce the feature dimensionality in machine learning that ultimately improved the predictive power of our gene-to-trait models. Further, we functionally validated seven candidate transcription factors with predictive power for NUE outcomes in Arabidopsis and one in maize. Moreover, application of our evolutionarily informed pipeline to other species including rice and mice models underscores its potential to uncover genes affecting any physiological or clinical traits of interest across biology, agriculture, or medicine.

A long term results of external beam radiation therapy in hemophilic arthropathy of the ankle in children.

Bleeding into joint space is critical to develop hemophilic arthropathy. To reduce the frequency of bleeding in the ankle joint of children with hemophilic arthropathy, low dose external beam irradiation was performed for 37 patients. Among them, 35 patients followed-up for longer than 1 yr (median 87 months) were enrolled for analysis. The average number of bleedings per month was 3.6 during one year prior to radiation therapy. After radiation therapy, it was decreased to 2.1 during the first year, after then it was maintained in the range of 1.0 to 1.5 until the tenth year. The bleeding frequency was reduced to 42% at the first year and it was maintained in the range of 58% to 73% from the second to the tenth year. Especially the patients who had 3 or more bleedings per month, and who had MRI score more than 3 showed significant decreases. During the follow-up period, growth disturbances and secondary malignancies were not found. External beam radiotherapy can be considered for the hemophilic patients with surgical or isotope therapies are not amenable.

Virtual Prism Adaptation Therapy: Protocol for Validation in Healthy Adults.

Hemispatial neglect is a common impairment after stroke. It is associated with poor functional and social outcomes. Therefore, an adequate intervention is imperative for the successful management of hemispatial neglect. However, the clinical use of various interventions is limited in real clinical practice. Prism adaptation therapy is one of the most evidence-based rehabilitation modalities to treat hemispatial neglect. To overcome any possible shortcoming that may occur with prism therapy, we developed a new system using immersive virtual reality and depth-sensing camera to create a virtual prism adaptation therapy (VPAT). To validate the VPAT system, we designed an experimental protocol investigating the behavioral errors and changes in cortical activation via the VPAT system. Cortical activation was measured by functional near infrared spectroscopy (fNIRS). The experiment consisted of four phases. All four included clicking, pointing or rest applied to right-handed healthy people. Clicking versus pointing was used for investigating the cortical region related with the gross motor task, and pointing with VPAT versus pointing without VPAT was used for investigating the cortical region associated with visuospatial perception. The preliminary results from four healthy participants showed that pointing errors by the VPAT system was similar to the conventional prism adaptation therapy. Further analysis with more participants and fNIRS data, as well as a study in patients with stroke may be required.

The effectiveness and safety of acupuncture for scoliosis: A protocol for systematic review and/or meta-analysis.

BACKGROUND: Scoliosis is a disease that affects all age groups and alters the three-dimensional deviation of the spinal axis. It is diagnosed when Cobb angle presents over 10 degrees and the reasons include aging, traumatic injuries, unknown origin, and disorders of congenital, neurological, musculoskeletal, and connective tissue. Scoliosis treatments are divided into surgical and conservative options. Surgery can correct the curved spine but has associated risks and economic burden. Conservative treatments, particularly bracing, prevent the progression of scoliosis, but still remains potential ingredient of curvation and patients poor compliance. Recent studies reported that various types of acupuncture can improve the curvation and the associated pain. However, there has been no systematic review on this issue. Therefore, this study will review the effectiveness and safety of acupuncture on scoliosis. METHODS: Searching randomized controlled trials about the use of acupuncture for scoliosis will be performed using multiple electronic databases, manual search, and contact to authors e-mail if needed. We will select studies by the pre-defined criteria and summarize the data on study participants, interventions, control groups, outcome measurement, adverse events, and risk of bias. The primary outcome will be the Cobb angle, which is objective, and the secondary outcomes are associated with patient-centered indices (pain, functional status, and quality of life), which are subjective and adverse events. We will use Review Manager software (Version 5.3; Copenhagen; The Nordic Cochrane Center, The Cochrane Collaboration, 2014) to perform a meta-analysis and Cochrane Collaboration "risk of bias" tools to assess the risk of bias. RESULTS: Our study will investigate the clinical evidence on the effectiveness and safety of acupuncture on scoliosis. CONCLUSION: Our study will be informative to scoliosis patients, clinicians, policy makers, and researchers working with conservative management for scoliosis.

Evaluation of the Reliability, Reproducibility and Validity of Digital Orthodontic Measurements Based on Various Digital Models among Young Patients.

The advantages of intraoral model scanning have yielded recent developments. However, few studies have explored the orthodontic clinical use of this technique particularly among young patients. This study aimed to evaluate the reliability, reproducibility and validity of the orthodontic measurements: tooth width, arch length and arch length discrepancy in each digital model obtained by model scanner and intraoral scanner, relative to a plaster model. Arch length measured using two methods: curved arch length (CAL) measured automatically by digital program and sum of sectional liner arch length (SLAL) measured sum of anterior and posterior liner arch lengths. Arch length discrepancy calculated each arch length measurement methods: curved arch length discrepancy (CALD) and sum of sectional liner arch length discrepancy (SLALD). Forty young patients were eligible for the study. A plaster model (P), model-scanned digital model (MSD) and intraoral scanned digital model (ISD) were acquired from each patient. The reliability of the measurements was evaluated using Pearson's correlation coefficient, while the reproducibility was evaluated using the intraclass correlation coefficient. The validity was assessed by a paired t-test. All measurements measured in P, MSD and ISD exhibited good reliability and reproducibility. Most orthodontic measurements despite of CAL in MSD exhibited high validity. Only the SLAL and SLALD in ISD group differed significantly, despite the good validity of the tooth width, CAL and CALD. The measurements based on the digital program appeared high reliability, reproducibility and accurate than conventional measurement. However, SLAL and SLALD in ISD group appeared shorter because of distortion during intraoral scanning. However, this could be compensated by using digital programed curved arch. Although the validity of SLAL and SLALD in the ISD group differed statistically, the difference is not considered clinically significant. Although MSD and ISD are acceptable for a clinical space analysis, clinicians should be aware of digital model-induced errors.

A low cost kinect-based virtual rehabilitation system for inpatient rehabilitation of the upper limb in patients with subacute stroke: A randomized, double-blind, sham-controlled pilot trial.

BACKGROUND: We designed this study to prove the efficacy of the low-cost Kinect-based virtual rehabilitation (VR) system for upper limb recovery among patients with subacute stroke. METHODS: A double-blind, randomized, sham-controlled trial was performed. A total of 23 subjects with subacute stroke (<3 months) were allocated to sham (n = 11) and real VR group (n = 12). Both groups participated in a daily 30-minute occupational therapy for upper limb recovery for 10 consecutive weekdays. Subjects received an additional daily 30-minute Kinect-based or sham VR. Assessment was performed before the VR, immediately and 1 month after the last session of VR. Fugl-Meyer Assessment (FMA) (primary outcome) and other secondary functional outcomes were measured. Accelerometers were used to measure hemiparetic upper limb movements during the therapy. RESULTS: FMA immediately after last VR session was not different between the sham (46.8 ±â€Š16.0) and the real VR group (49.4 ±â€Š14.2) (P = .937 in intention to treat analysis). Significant differences of total activity counts (TAC) were found in hemiparetic upper limb during the therapy between groups (F2,26 = 4.43; P = .22). Real VR group (107,926 ±â€Š68,874) showed significantly more TACs compared with the sham VR group (46,686 ±â€Š25,814) but there was no statistical significance between real VR and control (64,575 ±â€Š27,533). CONCLUSION: Low-cost Kinect-based upper limb rehabilitation system was not more efficacious compared with sham VR. However, the compliance in VR was good and VR system induced more arm motion than control and similar activity compared with the conventional therapy, which suggests its utility as an adjuvant additional therapy during inpatient stroke rehabilitation.

Basics of particle therapy I: physics.

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest.

Co-authorship patterns and networks of Korean radiation oncologists.

PURPOSE: This research aimed to analyze the patterns of co-authorship network among the Korean radiation oncologists and to identify attributing factors for the formation of networks. MATERIALS AND METHODS: A total of 1,447 articles including contents of 'Radiation Oncology' and 'Therapeutic Radiology' were searched from the KoreaMed database. The co-authorship was assorted by the author's full name, affiliation and specialties. UCINET 6.0 was used to figure out the author's network centrality and the cluster analysis, and KeyPlayer 1.44 program was used to get a result of key player index. Sociogram was analyzed with the Netdraw 2.090. The statistical comparison was performed by a t-test and ANOVA using SPSS 16.0 with p-value < 0.05 as the significant value. RESULTS: The number of articles written by a radiation oncologist as the first author was 1,025 out of 1,447. The pattern of co-authorship was classified into five groups. For articles of which the first author was a radiation oncologist, the number of single-author articles (type-A) was 81; single-institution articles (type-B) was 687; and multiple-author articles (type-C) was 257. For the articles which radiation oncologists participated in as a co-author, the number of single-institution articles (type-D) was 280 while multiple-institution articles (type-E) were 142. There were 8,895 authors from 1,366 co-authored articles, thus the average number of authors per article was 6.51. It was 5.73 for type-B, 6.44 for type-C, 7.90 for type-D, and 7.67 for type-E (p = 0.000) in the average number of authors per article. The number of authors for articles from the hospitals published more than 100 articles was 7.23 while form others was 5.94 (p = 0.005). Its number was 5.94 and 7.16 for the articles published before and after 2001 (p = 0.000). The articles written by a radiation oncologist as the first author had 5.92 authors while others for 7.82 (p = 0.025). Its number was 5.57 and 7.71 for the Journal of the Korean Society for Therapeutic Radiology and Oncology and others (p = 0.000), respectively. Among the analysis, a significant difference in the average number of author per article was indicated. The out-degree centrality of network among authors was 4.26% (2.03.7.09%) while in-degree centrality was 1.31% (0.53.2.84%). The three significant nodes were classified and listed as following: Choi, Eun Kyung for 1991-1995, Kim, Dae Young for 1998-2001, Park, Won and Lee, Sang Wook for 2003-2010. Choi, Eun Kyung and Kim, Dae Young appeared in two cases, and ranked as the highest degree in centrality. In the key player analysis, Choi, Eun Kyung and Lee, Sang Wook appeared in two cases, and ranked as the highest. From the cluster analysis, Sungkyunkwan University, Seoul National University and Yonsei University revealed as the three large clusters when Ulsan University, Chonnam National University, and Korea Institute of Radiological & Medical Science as the medium clusters. CONCLUSION: The Korean radiation oncologist's society shows a closed network with numerous relationships among the particular clusters, and the result indicates it is different from other institutions in the pattern of co-authorship formation of the major hospitals.

Analysis of Scientific Publication Networks among Medical Schools in Korea.

OBJECTIVES: This research was intended to analyze the special characteristics and structure of social networks among Korean medical schools for the purpose of providing knowledge regarding medical field structure, dynamics, and potential paradigm development. METHODS: A collaborative 12-year data set of 35,469 published articles in the SCOPUS® database was analyzed. Among ISI subcategories, 61 having more than 20 articles were scrutinized. Following identification of correspondence and co-authorship, centralization indices and Key Player analysis were run for each subcategory. Medical schools were grouped into uniform clusters with convergence of iterated correlation (CONCOR) for structural equivalence. Finally, multidimensional scaling was used to visualize similarities. RESULTS: All centralization indexes analyzed demonstrated a shift in the degree of centralization in the network of medical schools throughout the period examined. Betweenness centrality and eigenvector centrality in particular revealed a dramatic change indicating minimization of the role of a specific "gatekeeper". Key Player analysis confirmed Seoul National University as a constant 'key player' throughout the period evaluated and for the subcategories examined as well. CONCLUSIONS: This study provided insight into the scientific network among the medical schools of Korea. By understanding this network, a strategy to strengthen the basis of research may be developed.

RNA interference in vitro and in vivo using an arginine peptide/siRNA complex system.

Efficient delivery systems are required to exploit the enormous potential of RNA interference. We introduced an arginine peptide-based small-interference RNA (siRNA) delivery system for in vitro and in vivo RNA interference. Arginine peptides formed stable complexes with siRNA and transduced siRNA into COS-7 cells in vitro, resulting in efficient gene silencing. The intracellular path of the peptide/siRNA complex was investigated in live cells using fluorescent labeling and confocal microscopy. At 24h after transfection, most of the siRNA signals were observed in the perinuclear region, indicating that siRNA was targeted to the perinuclear region for interactions with RNA-induced silencing complex (RISC). Effective in vivo RNA interference was achieved in a mouse model bearing a subcutaneous tumor. Intratumoral administration of HER-2-specific siRNA/peptide complexes resulted in a marked reduction of tumor growth. Body weight monitoring during treatment showed that our delivery system was nontoxic. Our approach offers the potential for siRNA delivery in various in vitro and in vivo applications.