Recent Advances in the Pathogenesis and Clinical Evaluation of Portal Hypertension in Chronic Liver Disease

Kotani Kohei,Kawada Norifumi 거트앤리버 소화기연관학회협의회 2024 Gut and Liver Vol.18 No.1

In chronic liver disease, hepatic stellate cell activation and degeneration of liver sinusoidal endothelial cells lead to structural changes, which are secondary to fibrosis and the presence of regenerative nodules in the sinusoids, and to functional changes, which are related to vasoconstriction. The combination of such changes increases intrahepatic vascular resistance and causes portal hypertension. The subsequent increase in splanchnic and systemic hyperdynamic circulation further increases the portal blood flow, thereby exacerbating portal hypertension. In clinical practice, the hepatic venous pressure gradient is the gold-standard measure of portal hypertension; a value of ≥10 mm Hg is defined as clinically significant portal hypertension, which is severe and is associated with the risk of liver-related events. Hepatic venous pressure gradient measurement is somewhat invasive, so evidence on the utility of risk stratification by elastography and serum biomarkers is needed. The various stages of cirrhosis are associated with different outcomes. In viral hepatitis-related cirrhosis, viral suppression or elimination by nucleos(t)ide analog or direct-acting antivirals results in recompensation of liver function and portal pressure. However, careful follow-up should be continued, because some cases have residual clinically significant portal hypertension even after achieving sustained virologic response. In this study, we reviewed the current and future prospects for portal hypertension.

Transportation Issues in Rural Healthcare

Kotani, Kazuhiko The Korean Society for Preventive Medicine 2020 Journal of Preventive Medicine and Public Health Vol.53 No.2

Exponentially Weighted Moving Average Chart for High-Yield Processes

Kotani, Takayuki,Kusukawa, Etsuko,Ohta, Hiroshi Korean Institute of Industrial Engineers 2005 Industrial Engineeering & Management Systems Vol.4 No.1

Borror et al. discussed the EWMA(Exponentially Weighted Moving Average) chart to monitor the count of defects which follows the Poisson distribution, referred to the $EWMA_c$ chart, as an alternative Shewhart c chart. In the $EWMA_c$ chart, the Markov chain approach is used to calculate the ARL (Average Run Length). On the other hand, in order to monitor the process fraction defectives P in high-yield processes, Xie et al. presented the CCC(Cumulative Count of Conforming)-r chart of which quality characteristic is the cumulative count of conforming item inspected until observing $r({\geq}2)$ nonconforming items. Furthermore, Ohta and Kusukawa presented the $CS(Confirmation Sample)_{CCC-r}$ chart as an alternative of the CCC-r chart. As a more superior chart in high-yield processes, in this paper we present an $EWMA_{CCC-r}$ chart to detect more sensitively small or moderate shifts in P than the $CS_{CCC-r}$ chart. The proposed $EWMA_{CCC-r}$ chart can be constructed by applying the designing method of the $EWMA_C$ chart to the CCC-r chart. ANOS(Average Number of Observations to Signal) of the proposed chart is compared with that of the $CS_{CCC-r}$ chart through computer simulation. It is demonstrated from numerical examples that the performance of proposed chart is more superior to the $CS_{CCC-r}$ chart.

An Efficient Fluorescence Sensor for Superoxide with an Acridinium Ion-Linked Porphyrin Triad

Kotani, Hiroaki,Ohkubo, Kei,Crossley, Maxwell J.,Fukuzumi, Shunichi American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.29

<P>Addition of potassium superoxide with 18-crown-6 ether (KO<SUB>2</SUB><SUP>•–</SUP>–18-crown-6) to a toluene solution of an acridinium ion-linked porphyrin triad (Acr<SUP>+</SUP>–H<SUB>2</SUB>P–Acr<SUP>+</SUP>) resulted in a remarkable enhancement of the fluorescence intensity. Thus, Acr<SUP>+</SUP>–H<SUB>2</SUB>P–Acr<SUP>+</SUP> acts as an efficient fluorescence sensor for superoxide. Electron transfer from KO<SUB>2</SUB><SUP>•–</SUP>–18-crown-6 to the Acr<SUP>+</SUP> moiety to produce the two-electron-reduced species (Acr<SUP>•</SUP>–H<SUB>2</SUB>P–Acr<SUP>•</SUP>) results in inhibition of the fluorescence quenching via photoinduced electron transfer, as revealed by laser flash photolysis measurements.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2011/jacsat.2011.133.issue-29/ja204161j/production/images/medium/ja-2011-04161j_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja204161j'>ACS Electronic Supporting Info</A></P>

Integration of Tactile Information and Visual Information Using A Glass Substrate Surface Acoustic Wave Tactile Display

Hiroyuki Kotani,Masaya Takasaki,Takeshi Mizuno,Takaaki Nara 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Accuracy of Pedicle Screw Placement in Scoliosis Surgery: A Comparison between Conventional Computed Tomography-Based and O-Arm-Based Navigation Techniques

Toshiaki Kotani,Tsutomu Akazawa,Tsuyoshi Sakuma,Kayo Koyama,Tetsuharu Nemoto,Kento Nawata,Atsuro Yamazaki,Shohei Minami 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.3

Study Design: Retrospective study. Purpose: We compared the accuracy of O-arm-based navigation with computed tomography (CT)-based navigation in scoliotic surgery. Overview of Literature: No previous reports comparing the results of O-arm-based navigation with conventional CT-based navigation in scoliotic surgery have been published. Methods: A total of 222 pedicle screws were implanted in 29 patients using CT-based navigation (group C) and 416 screws were implanted in 32 patients using O-arm-based navigation (group O). Postoperative CT was performed to assess the screw accuracy, using the established Neo classification (grade 0: no perforation, grade 1: perforation <2 mm, grade 2: perforation ≥2 and <4, and grade 3: perforation ≥4 mm). Results: In group C, 188 (84.7%) of the 222 pedicle screw placements were categorized as grade 0, 23 (10.4%) were grade 1, 11 (5.0%) were grade 2, and 0 were grade 3. In group O, 351 (84.4%) of the 416 pedicle screw placements were categorized as grade 0, 52 (12.5%) were grade 1, 13 (3.1%) were grade 2, and 0 were grade 3. Statistical analysis showed no significant difference in the prevalence of grade 2–3 perforations between groups C and O. The time to position one screw, including registration, was 10.9±3.2 minutes in group C, but was significantly decreased to 5.4±1.1 minutes in group O. Conclusions: O-arm-based navigation facilitates pedicle screw insertion as accurately as conventional CT-based navigation. The use of O-arm-based navigation successfully reduced the time, demonstrating advantages in the safety and accuracy of pedicle screw placement for scoliotic surgery.

Korea - Japan Joint Symposium on Joining Technology : New Precise Joining Technology ) ; REACTION OF ALLOYING ELEMENT WITH SUPERFICIAL OXIDE FILM OF AL - ALLOYS DURING DIFFUSION BONDING

(K . Kotani),(K . Ikeuchi),(J . P . Jung),F . Matsuda 서울시립대학교 산업기술연구소 2000 국제학술SYMPOSIUM논문집 Vol.8 No.2

Evaluation of flick-motion based representation used for presenting Japanese kana characters by tactile information display device

Kentaro Kotani,Hiroki Sato,Satoshi Suzuki,Takafumi Asao 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

This study introduces a potential technique for Japanese kana characters on tactile information display device (tactile display) that allows the user effectively perceived. Currently tactile display has not been developed for the purpose of character information transmission due to poor performance of recognition rates in terms of characters. The purpose of this study is to evaluate a novel technique, flick motion based display, for presenting Japanese kana characters on the tactile display (FMR tactile display). Flick motion is normally used as an input scheme for mobile devices, as one of touch screen gestures. In Japan, a set of flick motions on 10 isolated areas on the touch screen is especially assigned as Japanese kana character entry. Many Japanese mobile phone users have its mental model, which was applied to present character information as an output scheme into tactile display. Experiments were conducted to evaluate how the implemented presentation system can perform well to let the user perceive kana characters. A total of 10 subjects, including users unfamiliar to FMR, participated in the study. The subjects located their right hand on the tactile display and a kana character by using FMR was given on the display. They responded the characters as soon as they perceived. Number of correct recognition of the characters were obtained throughout the set of trials consisted of 20 character presentations. The results showed that the average correct recognition rates were 41.5 percent and the average reaction time was 6.8 seconds, which were faster than conventional trace-based character representations. The results suggested that fine adjustment of the palm to the tactile display and changing stimulus duration would improve the performance of recognition rates.

Leptin:Adiponectin Ratio and Metabolic Syndrome in the General Japanese Population

Kazuhiko Kotani,Naoki Sakane 대한진단검사의학회 2011 Annals of Laboratory Medicine Vol.31 No.3

Background: Circulating leptin:adiponectin ratio (L:A) is a potential surrogate marker for cardiometabolic diseases; however, the relationship of the L:A with the occurrence of metabolic syndrome (MetS) has not yet been fully explored in the general Japanese population. Methods: We enrolled 678 Japanese subjects (208 men and 470 women, mean age: 58.8±14.4 [SD] yr; mean body mass index: 23.6±3.3 kg/m2) in this study, and determined their MetS status by using the National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP) recommendations with minor modifications for the Japanese population. Biochemical markers such as leptin and adiponectin present in blood were measured. The statistical analyses performed were gender-based. Results: The L:A in subjects with MetS was significantly higher than that in subjects without MetS, regardless of gender. The L:A also showed a significant and gradual increase corresponding to the increase in the number of components of MetS present in both the genders (trend P<0.01). The cut-off level of the L:A to detect MetS was 0.59 (sensitivity: 0.72, specificity: 0.70) in men and 1.04 (sensitivity: 0.72, specificity: 0.69) in women. Conclusions: These results suggest that the L:A can serve as a clinically useful marker for detecting MetS characteristics in the general Japanese population. The clinical application of this laboratory index for detecting MetS should be assessed in future studies. Background: Circulating leptin:adiponectin ratio (L:A) is a potential surrogate marker for cardiometabolic diseases; however, the relationship of the L:A with the occurrence of metabolic syndrome (MetS) has not yet been fully explored in the general Japanese population. Methods: We enrolled 678 Japanese subjects (208 men and 470 women, mean age: 58.8±14.4 [SD] yr; mean body mass index: 23.6±3.3 kg/m2) in this study, and determined their MetS status by using the National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP) recommendations with minor modifications for the Japanese population. Biochemical markers such as leptin and adiponectin present in blood were measured. The statistical analyses performed were gender-based. Results: The L:A in subjects with MetS was significantly higher than that in subjects without MetS, regardless of gender. The L:A also showed a significant and gradual increase corresponding to the increase in the number of components of MetS present in both the genders (trend P<0.01). The cut-off level of the L:A to detect MetS was 0.59 (sensitivity: 0.72, specificity: 0.70) in men and 1.04 (sensitivity: 0.72, specificity: 0.69) in women. Conclusions: These results suggest that the L:A can serve as a clinically useful marker for detecting MetS characteristics in the general Japanese population. The clinical application of this laboratory index for detecting MetS should be assessed in future studies.

Disambiguation of Coordinate Expressions in Japanese by Extracting Mutual Case Relation

( Yoshiyuki Kotani ) 한국언어정보학회 2002 국제 워크샵 Vol.2002 No.-

Japanese coordinate noun phrases by the particle TO are often ambiguous on whether it means two parallel propositions (and) ,or a mutual case relation (with or against) , as deep case structure. It was a hard problem to determine it, though they are widely used. We propose a method of solving the ambiguity by analyzing mutualness of verbs and adjectives. The mutualness is determined by three features of each verb or adjective. The first feature indicates permission of mutual expression in the subject, and the second in the object. The last shows if a verb is voluntary. Using this method we design a parsing mechanism, where matching of features is represented as neutralization between predicate arguments.