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Dive into the research topics where Akihisa Kamataki is active.

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Featured researches published by Akihisa Kamataki.


International Journal of Rheumatic Diseases | 2012

Interleukin-6 upregulates expression of ADAMTS-4 in fibroblast-like synoviocytes from patients with rheumatoid arthritis

Yoshikuni Mimata; Akihisa Kamataki; Shinya Oikawa; Kenya Murakami; Miwa Uzuki; Tadashi Shimamura; Takashi Sawai

Aim:  A disintegrin‐like and metalloproteinase with thrombospondin type 1 motif (ADAMTS)‐4 and ADAMTS‐5 play crucial roles in the cleavage of aggrecan. Several recent studies have demonstrated the effect of cytokines such as interleukin (IL)‐1β, tumor necrosis factor‐α and transforming growth factor‐β on the expression of ADAMTS‐4 and ADAMTS‐5 in fibroblast‐like synoviocytes (FLS). However, the effect of IL‐6 remains unclear. The aim of this study is to investigate the expression of ADAMTS‐4 and ADAMTS‐5 in FLS of rheumatoid arthritis (RA) patients after IL‐6 stimulation.


The Journal of Rheumatology | 2011

Cartilage Destruction Is Partly Induced by the Internal Proteolytic Enzymes and Apoptotic Phenomenon of Chondrocytes in Relapsing Polychondritis

Naohisa Ouchi; Miwa Uzuki; Akihisa Kamataki; Yasuhiro Miura; Takashi Sawai

Objective. We analyzed 9 cases by immunohistochemical studies in order to elucidate the mechanisms of cartilage destruction in relapsing polychondritis (RP), which often involves the external auricle and respiratory tract through immunological disorder. Methods. Cartilage tissues were obtained during surgical operations. Cell species in the granulation tissues, especially near the cartilage, were identified by cell-surface markers [CD3, CD4, CD8, CD20, CD45 (LCA), and CD68]. The proteolytic enzymes expressed in the cells in the perichondral granulation and in chondrocytes themselves were analyzed by immunohistochemical studies using anti-matrix metalloproteinase (MMP) -1, -3, -8, -9, and -13, and cathepsin D, K, L, and elastase antibodies. Apoptosis and nitric oxide (NO), an apoptosis-related factor, were also examined using ApopTag and antinitrotyrosine antibody, respectively. Results. Among cell species that infiltrated in perichondral granulation, LCA, CD68 (monocytes/macrophages), and CD4 cells were dominant in number; MMP-8, MMP-9, and elastase were expressed only in the perichondral granulation; whereas MMP-3 and cathepsin K and L were detected in both chondrocytes and granulations. Out of 9 cases examined, 6 revealed apoptotic cells in excess of 50% of chondrocytes. There was a strong correlation between the number of apoptotic cells and the number of MMP-3-positive (r = 0.83) and cathepsin K-positive cells (r = 0.92). Abundant NO-expressing cells were observed in the chondrocytes in degenerated cartilage, similar to apoptosis. Conclusion. Cartilage destruction in polychondritis is induced not only by perichondral inflammation, but also by intrinsic factors expressed in chondrocytes themselves, including certain kinds of proteolytic enzymes and apoptosis.


International Journal of Rheumatic Diseases | 2011

Quantitative measurement of serum hyaluronic acid molecular weight in rheumatoid arthritis patients and the role of hyaluronidase

Yoshiko Sasaki; Miwa Uzuki; Kenji Nohmi; Hironoshin Kitagawa; Akihisa Kamataki; Masataka Komagamine; Kenya Murakami; Takashi Sawai

Aim:  Hyaluronic acid (HA) is a glycosaminoglycan and is essential for protecting the cartilage surface by its physical property. It is known that serum HA concentration in rheumatoid arthritis (RA) patients is higher than in healthy volunteer. However, molecular weight (MW) of serum HA in RA patients is not clear, since it needs a large sample volume to assay serum HA MW. The aim of this study is to establish the method for measuring serum HA MW in small sample sizes and to assess the association between serum HA MW and hyaluronidase (HAase) activity.


Journal of Pathology Informatics | 2010

The state of telepathology in Japan

Takashi Sawai; Miwa Uzuki; Akihisa Kamataki; Ikuo Tofukuji

Telepathology began in Japan in the early 1990s in response to advances in computing and telecommunications equipment development and a dearth of pathologists. Telepathology in Japan is most often used for rapid intraoperative pathological diagnosis using frozen section, followed by second opinions and consultation. Intraoperatively, telepathology is used to determine malignancy, metastasis of malignant tumors, and the extent of excision. Infrastructure and equipment has evolved from analog lines to digital lines like integrated services digital network (ISDN) and asymmetric digital subscriber line (ADSL), and recently to fiber optics. The use of communications satellites is also being considered. Image quality is being improved to Hi-Vision (HDTV), and from still images to real-time video. Digital microscopy has been introduced, and is used in education and consultation.


Allergology International | 2011

A Histopathological Study of Pulmonary Hypertension in Connective Tissue Disease

Nobuhito Sasaki; Akihisa Kamataki; Takashi Sawai

Connective tissue diseases (CTD), such as systemic sclerosis (SSc), systemic lupus erythematosus (SLE), and mixed connective tissue disease (MCTD), develop pulmonary hypertension (PH). Generally all PH cases associated with any CTD are classified into the same PH group. However, histological examination shows both common and specific lesions for each disease. In patients with SLE, fibrosis is generally rare and mild. The findings of PH in SLE are similar to those in primary pulmonary hypertension. Many cases of SSc are accompanied by fibrosis. MCTD is rather close to SSc. Arterial and arteriolar lesions of MCTD are characterized by fibrous intimal thickening. In this review, we describe the pathological features of PH associated with each CTD.


Diagnostic Pathology | 2012

Development of a teledermatopathology consultation system using virtual slides

Ikunori Nakayama; Tsubasa Matsumura; Akihisa Kamataki; Miwa Uzuki; Kenji Saito; James Hobbs; Toshihide Akasaka; Takashi Sawai

BackgroundAn online consultation system using virtual slides (whole slide images; WSI) has been developed for pathological diagnosis, and could help compensate for the shortage of pathologists, especially in the field of dermatopathology and in other fields dealing with difficult cases. This study focused on the performance and future potential of the system.MethodIn our system, histological specimens on slide glasses are digitalized by a virtual slide instrument, converted into web data, and up-loaded to an open server. Using our own purpose-built online system, we then input patient details such as age, gender, affected region, clinical data, past history and other related items. We next select up to ten consultants. Finally we send an e-mail to all consultants simultaneously through a single command. The consultant receives an e-mail containing an ID and password which is used to access the open server and inspect the images and other data associated with the case. The consultant makes a diagnosis, which is sent to us along with comments.Because this was a pilot study, we also conducted several questionnaires with consultants concerning the quality of images, operability, usability, and other issues.ResultsWe solicited consultations for 36 cases, including cases of tumor, and involving one to eight consultants in the field of dermatopathology. No problems were noted concerning the images or the functioning of the system on the sender or receiver sides. The quickest diagnosis was received only 18 minutes after sending our data. This is much faster than in conventional consultation using glass slides. There were no major problems relating to the diagnosis, although there were some minor differences of opinion between consultants. The results of questionnaires answered by many consultants confirmed the usability of this system for pathological consultation. (16 out of 23 consultants.)ConclusionWe have developed a novel teledermatopathological consultation system using virtual slides, and investigated the usefulness of the system. The results demonstrate that our system can be a useful tool for international medical work, and we anticipate its wider application in the future.Virtual slidesThe virtual slides for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/1902376044831574


Pathology Research and Practice | 2011

Histological analysis of esophageal muscular layers from 27 autopsy cases with mixed connective tissue disease (MCTD)

Miwa Uzuki; Akihisa Kamataki; Mika Watanabe; Nobuhito Sasaki; Yasuhiro Miura; Takashi Sawai

Esophageal symptoms in mixed connective tissue disease (MCTD) have been investigated radiologically. We investigated the esophageal lesions in MCTD histopathologically, and analyzed relationships between these lesions and autoantibodies extracted from the serum of MCTD patients. Esophageal tissues from 27 MCTD patients submitted to autopsy were examined. We compared histopathological features of the esophagus in different wall layers from the mucosa, submucosa, and muscular layer to the adventitia, and in the upper, middle, and lower portions of esophagus. The most striking change observed was severe atrophy and occasional loss of smooth muscle cells in the muscular layer, followed by fibrosis. These muscular changes were particularly prominent in the inner layer of the lower esophagus. Immunohistochemically, degenerated muscular tissues of the esophagus were positive for anti-IgG and anti-C3 antibodies, but not for anti-IgM antibodies. IgG fractions extracted from three MCTD patients were immunohistochemically used to examine whether some antibodies in MCTD patients showed reactivity for esophageal components. The IgG fractions isolated from MCTD patients reacted with smooth muscle from non-connective tissue disease cases, suggesting that some serum antibodies may trigger esophageal changes. These findings suggest that esophageal lesions associated with clinical dysphagia in MCTD may be related to autoantibodies.


Experimental Lung Research | 2010

Analysis of pulmonary allergic vasculitis with eosinophil infiltration in asthma model of mice

Kohei Yamauchi; Nobuhito Sasaki; Miyuki Niisato; Akihisa Kamataki; Toshiki Shikanai; Yutaka Nakamura; Hitoshi Kobayashi; Akira Suwabe; Hiroyuki Kanno; Takashi Sawai; Hiroshi Inoue

ABSTRACT Here the authors report pulmonary allergic vasculitis with eosinophil infiltration in an asthma model of mice and investigated its pathogenesis. C57BL/6 and BALB/c mice were sensitized with ovalbumin (OVA). After the inhalation of OVA, the authors measured the cell number and cytokine concentration in the blood and bronchoalveolar lavage fluid (BALF). The authors also examined the histological changes of the pulmonary. The number of eosinophils increased in the blood and BALF in both strains; however, the number in C57BL/6 in BALF was significantly higher than that in BALB/c. Histological analysis demonstrated severe vasculitis of the pulmonary arteries with derangement of the muscle layer and smooth muscle cell hyperplasia in C57BL/6. Semiquantitative analysis of the severity of vasculitis in the pulmonary arteries revealed that the internal vascular space was highly reduced by smooth muscle hyperplasia in C57BL/6 compared to BALB/c mice. The concentrations of interleukin (IL)-4, IL-5, and interferon (IFN)-γ in BALF of C57BL/6 were significantly high compared to those of BALB/c. C57BL/6 mice exhibited severe allergic vasculitis in the pulmonary arteries compared to BALB/c mice. The high concentrations of IL-4, IL-5, and IFN-γ in the lung may play a critical role in the pathogenesis of allergic vasculitis in C57BL/6 mice.


Journal of Electron Microscopy | 2013

Serial block-face scanning electron microscopy combined with double-axis electron beam tomography provides new insight into cellular relationships

Takashi Sawai; Akihisa Kamataki; Miwa Uzuki; Kinji Ishida; Tomohito Hanasaka; Kensuke Ochi; Takahito Hashimoto; Takashi Kubo; Akinari Morikawa; Takahiro Ochi; Koujiro Tohyama

To evaluate the advantages of combination of two advanced electron microscopic technologies such as serial block-face scanning electron microscopy and double-axis electron beam tomography, we analyzed the three-dimensional morphology of cellular relationships between dendritic and plasma cells in the synovial membrane from patients with rheumatoid arthritis, using the combined approach.


International Journal of Rheumatic Diseases | 2016

Zymographic analysis using gelatin-coated film of the effect of etanercept on the extracellular matrix-degrading activity in synovial fluids of rheumatoid arthritis patients

Akihisa Kamataki; Mutsuko Ishida; Masataka Komagamine; Masaaki Yoshida; Takanobu Ando; Takashi Sawai

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Most RA patients develop cartilage and bone destruction, and various proteinases are involved in the destruction of extracellular matrix of cartilage and bone. The aim of this study is to evaluate the utility of our newly developed method to measure total gelatinolytic activity. We adopted this method for measurement in synovial fluid from RA patients treated by the anti‐rheumatic drug etanercept (ETN), a recombinant human soluble tumor necrosis factor receptor fusion protein, and compared the findings with clinical and laboratory data.

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Takashi Sawai

Iwate Medical University

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Miwa Uzuki

Iwate Medical University

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Yasuhiro Miura

Iwate Medical University

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Kenya Murakami

Iwate Medical University

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Kenji Saito

Iwate Medical University

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