Kenichi Yokobayashi
Hiroshima University
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Featured researches published by Kenichi Yokobayashi.
Parasites & Vectors | 2015
Shigehiko Uni; Masako Fukuda; Yasushi Otsuka; Nobuo Hiramatsu; Kenichi Yokobayashi; Hiroshi Takahashi; Susumu Murata; Kenji Kusatake; Eishin Morita; Haruhiko Maruyama; Hideo Hasegawa; Kuninori Shiwaku; Rosli Ramli; Mohd Sofian Azirun; Hiroyuki Takaoka
BackgroundZoonotic infections with Onchocerca species are uncommon, and to date only 25 clinical cases have been reported worldwide. In Japan, five previous zoonotic infections were concentrated in Oita, Kyushu (the southern island), with one previous case in Hiroshima in the western part of Honshu (the main island). The causative agent in Japan was identified as Onchocerca dewittei japonica Uni, Bain & Takaoka, 2001 from Japanese wild boars (Sus scrofa leucomystax Temminck, 1842). Here we report two infections caused by a female and male O. dewittei japonica, respectively, among residents of Hiroshima and Shimane Prefectures in the western part of Honshu.MethodsIn both cases, nodules were surgically removed. The parasites in nodules were identified on the basis of their histopathological characteristics. Identification was confirmed by sequencing the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from worms in the tissues used in the histological preparations.ResultsCase 1 was a 61-year-old woman from Hiroshima Prefecture who complained of a painful subcutaneous nodule on the back of her right hand. The causative agent was identified as a female O. dewittei japonica owing to transverse ridges on the cuticle and molecular analysis. Case 2 was a 78-year-old woman from Shimane Prefecture who had a painful nodule in the left temporal region. Histopathological characteristics and cox1 sequencing of the worm indicated that the causative agent was a male O. dewittei japonica.ConclusionsFor Cases 1 and 2, we diagnosed the causative agents as a female and male O. dewittei japonica, respectively. These findings indicate the spread of a zoonosis caused by O. dewittei japonica in the western part of Honshu, where wild boars have recently extended their habitats because of decreased annual snowfall, unused rice fields and a decline in the number of hunters in Japan. The O. dewittei japonica infection rate among wild boars was reported as 78% in Shimane Prefecture, in the western part of Honshu. Therefore, in the near future, zoonotic onchocercosis is likely to occur in Honshu as well as Kyushu, where wild boars, blackfly vectors and humans share the same habitat.
BMJ Open | 2014
Kenichi Yokobayashi; Masato Matsushima; Takamasa Watanabe; Yasuki Fujinuma; Susumu Tazuma
Objective To determine the incidence of fever among elderly persons under home medical management, diagnosis at fever onset and outcomes from a practical standpoint. Design Prospective cohort study. Setting 5 clinics in residential areas of Tokyo that process an average of 50–200 outpatients/day. Participants Patients (n=419) aged ≥65 years who received home medical management from the five clinics between 1 October 2009 and 30 September 2010. Main outcome measures Fever (≥37.5°C or ≥1.5°C above usual body temperature), diagnosis at onset and outcomes (cure at home, hospitalisation and death). Results The incidence of fever was 2.5/1000 patient-days (95% CI 2.2 to 2.8). Fever occurred at least once (229 fever events) among one-third of the participants during the study period. Fever was more likely to arise in the wheelchair users or bedridden than in ambulatory individuals (HR 1.9 (95% CI 1.3 to 2.8; p<0.01); in patients with moderate-to-severe rather than those with none-to-mild cognitive impairment (HR, 1.7 (95% CI 1.1 to 2.6, p=0.01); and in those whose care-need levels were ≥3 rather than ≤2 (HR, 4.5 (95% CI 2.9 to 7.0; p<0.01). The causes of fever were pneumonia/bronchitis (n=103), skin and soft tissue infection (n=26), urinary tract infection (n=22) and the common cold (n=13). Fever was cured in 67% and 23% of patients at home and in hospital, respectively, and 5% of patients each died at home and in hospital. Antimicrobial agents treated 153 (67%) events in the home medical care setting. Conclusions Fever was more likely to occur in those requiring higher care levels and the main cause of fever was pneumonia/bronchitis. Healthcare providers should consider the conditions of elderly residents with lower objective functional status.
Geriatrics & Gerontology International | 2013
Kenichi Yokobayashi; Masato Matsushima; Yasuki Fujinuma; Susumu Tazuma
In Japan, many elderly patients are managed at home, and fever is a common problem. This study examined the incidence of fever events in elderly patients on home medical management, and underlying disorders from the pragmatic standpoint. This study also investigated whether the care‐need level determined at the start of home care predicts fever onset.
Hepatology Research | 2015
Nobusuke Kishikawa; Keishi Kanno; Akiko Sugiyama; Kenichi Yokobayashi; Masafumi Mizooka; Susumu Tazuma
Ezetimibe inhibits cholesterol absorption by blocking Niemann–Pick C1‐like 1 proteins (NPC1L1) expressed in the small intestine. Because NPC1L1 is also expressed in human liver, ezetimibe conceivably alters biliary lipid compositions. Here, we performed a clinical trial investigating the effect of ezetimibe on biliary lipids using transnasal endoscopy for bile collection.
PLOS ONE | 2017
Kenichi Yokobayashi; Ichiro Kawachi; Katsunori Kondo; Naoki Kondo; Yuiko Nagamine; Yukako Tani; Kokoro Shirai; Susumu Tazuma
Aim The present study examined whether social support, informal socializing and social participation are associated with glycemic control in older people. Methods Data for this population-based cross-sectional study was obtained from the Japan Gerontological Evaluation Study (JAGES) 2010 linked to the annual health check-up data in Japan. We analyzed 9,554 individuals aged ≥65 years without the certification of needed long-term care. Multivariate logistic regression models were used to assess the effect of social support, informal socializing and social participations on glycemic control. The outcome measure was HbA1c ≥8.4%. Results 1.3% of the participants had a level of HbA1c over 8.4%. Better glycemic control was significantly associated with meeting with friends one to four times per month (odds ratio [OR] 0.51, 95% confidence interval [CI]0.30–0.89, compared to meeting with friends a few times per year or less) and participation in sports groups (OR 0.50, 95% CI 0.26–0.97) even after adjusting for other variables. Meeting with friends more than twice per week, receiving social support, and being married were not associated with better control of diabetes. Conclusions Meeting with friends occasionally is associated with better glycemic control among older people.
Journal of General and Family Medicine | 2017
Rinne Takeda; Masafumi Mizooka; Tomoki Kobayashi; Nobusuke Kishikawa; Kenichi Yokobayashi; Keishi Kanno; Susumu Tazuma
Fever of unknown origin (FUO) has many possible causes, so detailed history taking and physical examination are required. We identified key diagnostic features of medical history and physical findings for an efficient diagnosis of FUO.
Journal of Hepato-biliary-pancreatic Sciences | 2016
Nobusuke Kishikawa; Keishi Kanno; Akiko Sugiyama; Kenichi Yokobayashi; Masafumi Mizooka; Susumu Tazuma
Certain lipid‐lowering drugs increase bile lithogenicity. Here we investigated whether long‐term administration of ezetimibe, a new class of hypocholesterolemic agents designed to inhibit intestinal cholesterol absorption by inhibiting Niemann‐Pick C1‐like 1, alters bile lithogenicity in patients with hepatobiliary diseases.
Journal of General and Family Medicine | 2015
Masatoshi Matsumoto; Keisuke Takeuchi; Kenichi Yokobayashi; Susumu Tazuma
Despite massive intervention from Japans national and local governments, the skewed distribution of physicians remains a serious social problem. This review paper summarizes past literature and proposes a future strategy to deal with this sophisticated issue based on scientific evidence. There are several ways to achieve a more balanced distribution, the most feasible of which is to increase the number of generalists. This increase might be imminent with the establishment of a formal board certification for general practitioners (sougou‐shinryou‐i) and raising the number of rural subquota (chiikiwaku) entrants to medical school. All the stakeholders should co‐operate to take advantage of this great opportunity to increase the number of generalist physicians and solve Japans distribution problem.
Internal Medicine | 2018
Kazuki Kimura; Masafumi Mizooka; Kiyoshi Migita; Ryoko Ishida; Masatoshi Matsumoto; Satoshi Yamasaki; Nobusuke Kishikawa; Akihiro Kawahara; Yuka Kikuchi; Yuichiro Otani; Tomoki Kobayashi; Daisuke Miyamori; Takuya Ikuta; Hiroshi Nakamura; Kenichi Yokobayashi; Shuichi Iwamoto; Keishi Kanno; Hiromasa Ohira; Susumu Tazuma
Familial Mediterranean fever (FMF) is the most common genetic autoinflammatory disease, but it has been considered a rare disease in Japan. We herein describe five patients with FMF who were diagnosed both clinically and genetically at a single Japanese institute. A genetic investigation of Mediterranean fever (MEFV) detected heterozygosity for the compound mutations L110P/E148Q (n=2) and L110P/148Q/P369S/R406Q (n=1), and heterozygosity for M694I (n=1) and S503C (n=1). Colchicine prevented febrile attacks and accompanying symptoms in four patients. One patient with an S503C mutation showed resistance. Physicians should be aware of the characteristic symptoms, as well as the more unusual symptoms such as headache, when diagnosing FMF.
Internal Medicine | 2016
Ayuko Sokabe; Masafumi Mizooka; Rinne Sakemi; Tomoki Kobayashi; Nobusuke Kishikawa; Kenichi Yokobayashi; Keishi Kanno; Susumu Tazuma
Jugular paraganlioma is a benign, slow-growing tumor originating from the paraganglion cells and it is associated with catecholamine secretion. Paragangliomas can secrete Interleukin-6 (IL-6) and present as a systemic inflammatory syndrome; these characteristics have not been previously associated with jugular paragangliomas. A 63-year-old man with a jugular tumor in the skull base was referred to our hospital for an evaluation of pyrexia, back pain, and acute inflammation. His serum IL-6 level was elevated on admission and it decreased after radiotherapy. This is the first known case of a jugular paraganglioma exhibiting systemic inflammatory syndrome.