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Dive into the research topics where Yoichi Matsui is active.

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Featured researches published by Yoichi Matsui.


Experimental Biology and Medicine | 2003

Promotive effects of far-infrared ray on full-thickness skin wound healing in rats.

Hideyoshi Toyokawa; Yoichi Matsui; Junya Uhara; Hideto Tsuchiya; Shigeru Teshima; Hideki Nakanishi; A-Hon Kwon; Yoshihiko Azuma; Tetsuo Nagaoka; Takafumi Ogawa; Yasuo Kamiyama

The biological effects of far-infrared ray (FIR) on whole organisms remain poorly understood. The aim of our study was to investigate not only the hyperthermic effect of the FIR irradiation, but also the biological effects of FIR on wound healing. To evaluate the effect of FIR on a skin wound site, the speed of full-thickness skin wound healing was compared among groups with and without FIR using a rat model. We measured the skin wound area, skin blood flow, and skin temperature before and during FIR irradiation, and we performed histological inspection. Wound healing was significantly more rapid with than without FIR. Skin blood flow and skin temperature did not change significantly before or during FIR irradiation. Histological findings revealed greater collagen regeneration and infiltration of fibroblasts that expressed transforming growth factor-β1 (TGF-β1) in wounds in the FIR group than in the group without FIR. Stimulation of the secretion of TGF-β1 or the activation of fibroblasts may be considered as a possible mechanisms for the promotive effect of FIR on wound healing independent of skin blood flow and skin temperature.


Pancreas | 2000

Selective thermocoagulation of unresectable pancreatic cancers by using radiofrequency capacitive heating.

Yoichi Matsui; Akihiko Nakagawa; Yasuo Kamiyama; Koji Yamamoto; Nobuo Kubo; Yuzo Nakase

Recent investigations indicated that hyperthermia has antitumor effects. Several interstitial hyperthermic techniques were developed, and their clinical usefulness and safety were evaluated. However, few authors have attempted to study the use of interstitial hyperthermia for the treatment of pancreatic carcinomas. Therefore the efficacy of local selective thermocoagulation by radiofrequency was evaluated in 20 patients with unresectable carcinomas of the pancreas. A laparotomy and radiofrequency heating were performed in 20 patients with unresectable pancreatic carcinomas after informed consent. Local heat coagulation was induced by a 13.56-MHz radiofrequency pulse, produced by the heating apparatus. Four 2-cm needle electrodes were placed in the tumor, in a square array, at intervals of 2 cm. The heat was then administered for 15 min at a controlled temperature of 50 degrees C in the radiofrequency field (2x2x2 cc). All the patients were evaluated by computed tomographic scanning. Tumor markers in the blood also were assayed before and after the heating. Follow-up computed tomographic scans demonstrated that the tumor mass was enhanced heterogeneously, and after selective thermocoagulation, images revealed a change to a homogeneous low-density area. The blood levels of tumor markers decreased to below pretreatment values in 15 patients. Of the 20 cases treated with thermocoagulation, two had critical complications. One patient had septic shock, and another had gastrointestinal bleeding. The other 18 patients had no significant complications. These observations suggest that the selective thermocoagulation of tumor tissues using this equipment was relatively safe. These results justify further clinical trials for the treatment of patients with unresectable tumors without metastasis, or patients with benign pancreatic tumors such as insulinomas.


Journal of Hepatology | 2002

Improved prognosis of postoperative hepatocellular carcinoma patients when treated with functional foods: a prospective cohort study

Yoichi Matsui; Junya Uhara; Sohei Satoi; Masaki Kaibori; Hitoshi Yamada; Hiroaki Kitade; Atsusi Imamura; Soichiro Takai; Yusai Kawaguchi; A-Hon Kwon; Yasuo Kamiyama

BACKGROUND/AIMS Active hexose correlated compound (AHCC) is a newly developed functional food. In vitro experiments have shown that AHCC enhances natural killer cell activity, and may be considered a potent biological response modifier in the treatment of cancer patients. However, the effects of AHCC in a clinical setting have not been reported. We seek to determine whether AHCC can improve the prognosis of hepatocellular carcinoma (HCC) patients following surgical treatment. METHODS A prospective cohort study was performed from February 1, 1992 to December 31, 2001. A total of 269 consecutive patients with histologically confirmed HCC were studied. All of the patients underwent resection of a liver tumor. Time to treatment failure (disease recurrence or death) and ten parameters related to liver function after surgery were examined. RESULTS Of the 269 patients, 113 received AHCC orally after undergoing curative surgery (AHCC group). The AHCC group had a significantly longer no recurrence period (hazard ratio (HR), 0.639; 95% confidence interval (CI), 0.429-0.952; P=0.0277) and an increased overall survival rate (HR, 0.421; 95% CI, 0.253-0.701; P=0.0009) when compared to the control group by Coxs multivariate analysis. CONCLUSIONS This study suggests that AHCC intake can improve the prognosis of postoperative HCC patients.


The American Journal of Gastroenterology | 2001

Functional hepatic volume measured by technetium-99m-galactosyl-human serum albumin liver scintigraphy: comparison between hepatocyte volume and liver volume by computed tomography.

A.-Hon Kwon; Yoichi Matsui; Sang Kil Ha-Kawa; Yasuo Kamiyama

OBJECTIVES:We investigated the usefulness of measuring the functional hepatic volume by single-photon emission CT with 99m-technetium galactosyl-human serum albumin scintigraphy (GSA-LV). We then compared this value to the total hepatocyte volume and the hepatic volume determined from CT (CT-LV) in the patients with hepatobiliary tumors.METHODS:Forty-seven patients were divided into two groups, the SM group (subsegmentectomy and monosegmentectomy) and the DT group (disegmentectomy and trisegmentectomy). These groups were further divided into subgroups with or without chronic hepatitis or cirrhosis. The GSA-LV, CT-LV, and the total hepatocyte volume were then calculated. The GSA-LV and CT-LV measurements were performed preoperatively, at 2 and 4 wk, and at 3 and 6 months after surgery.RESULTS:The preoperative GSA-LV values were significantly correlated with the hepatocyte volume and the 15-min retention rate of indocyanine green (ICGR15). Similarly, the hepatocyte volume correlated well with the CT-LV and ICGR15. However, the CT-LV was correlated only with the ICGR15. Recovery of the GSA-LV in the DT group was delayed, and about 90% of the volumetric and functional regeneration was observed within 6 months after the hepatectomy. In contrast, the CT-LV of DT group patients with normal liver remnants returned to approximately 90% of their initial volume within 1 month after the hepatectomy, whereas patients with injured livers regenerated gradually and regained approximately 80% of their preoperative value by 6 months after the hepatectomy.CONCLUSIONS:We conclude that the measurement of functional hepatic volume using the GSA-LV is useful in fully evaluating hepatic function based on hepatocyte volume.


Pancreas | 2009

Surgical results after preoperative chemoradiation therapy for patients with pancreatic cancer.

Sohei Satoi; Hiroaki Yanagimoto; Hideyoshi Toyokawa; Kanji Takahashi; Yoichi Matsui; Hiroaki Kitade; Hynek Mergental; Noboru Tanigawa; Soichiro Takai; A-Hon Kwon

Objectives: The results of surgical therapy alone for pancreatic cancer are disappointing. We explored surgical results after neoadjuvant chemoradiation therapy (NACRT) for patients with pancreatic cancer that extended beyond the pancreas. Methods: Sixty-eight consecutive patients with pancreatic cancer who underwent pancreatic resection were included. Twenty-seven patients underwent surgical resection after NACRT (NACRT group). The other 41 patients were classified as surgery-alone group. Surgical results were compared in patients who underwent curative resection (R0/1) who were followed up for at least 25 months and underwent no adjuvant therapy. Results: A lower frequency of lymph node metastasis was observed in the NACRT group (P < 0.05). The frequency of residual tumor grading in the NACRT group was significantly different from that in surgery-alone (R0/1/2%, 52/15/33 vs 22/51/27; P = 0.0040). In R0/1 cases, overall survival and disease-free survival rates in the NACRT group (n = 18) were significantly longer than in surgery-alone (n = 30, P < 0.05). The rate of local recurrence in the NACRT group was significantly less than in surgery-alone (11% vs 47%, P = 0.0024). Conclusions: This single-institution experience indicates that NACRT is able to increase the resectability rate with clear margins and to decrease the rate of metastatic lymph nodes, resulting in improved prognosis of curative cases with pancreatic cancer that extended beyond the pancreas.


Cancer | 2001

Perioperative blood transfusion in hepatocellular carcinomas

A-Hon Kwon; Yoichi Matsui; Yasuo Kamiyama

The postoperative recurrence of hepatocellular carcinomas (HCC) associated with perioperative blood transfusion has been the subject of controversy. The authors prospectively investigated the relation between perioperative allogeneic blood transfusions, the recurrence free survival, and the immunologic profiles of patients with HCC who had undergone curative hepatic resections.


Journal of Surgical Oncology | 2009

Hepatic resection for hepatocellular carcinoma in the elderly

Masaki Kaibori; Kosuke Matsui; Morihiko Ishizaki; Takamichi Saito; Hiroaki Kitade; Yoichi Matsui; A-Hon Kwon

Aging of the population has significantly increased the number of elderly patients undergoing surgery for hepatocellular carcinoma (HCC). We aimed to compare the results of hepatectomy for HCC in patients ≥70 years old with those for younger patients.


World Journal of Surgery | 2006

Laparoscopic cholecystectomy in patients aged 80 years and over.

A-Hon Kwon; Yoichi Matsui

IntroductionThe aging population has led to a significant rise in the number of patients undergoing operations such as cholecystectomy. We have evaluated and compared the results of laparoscopic cholecystectomy (LC) in patients aged 80 years and over with those of patients aged between 65 and 79 years.MethodsA total of 471 patients aged 65 to 79 years (group 1) and 45 patients aged ≥80 years (group 2) underwent LC. All patients underwent preoperative spiral computed tomography after intravenous infusion cholangiography and intraoperative cholangiography.ResultsThere was a higher incidence of choledocholithiasis and gallbladder cancer in the patients ≥80 years of age. In addition, group 2 patients had a higher incidence of cardiopulmonary disease and higher American Association of Anesthesiology scores than did those in group 1. With respect to the conversion rate to open surgery, morbidity, mortality, and length of hospital stay, there were no significant differences between the two groups. There was a significantly higher incidence of positive bile cultures and gram-negative rods in group 2 patients than in those in group 1.ConclusionsOctogenarians tolerated LC well. Therefore, early elective LC should be encouraged to minimize morbidity and mortality in these elderly patients who have symptomatic cholelithiasis.


In Vitro Cellular & Developmental Biology – Animal | 1998

A SIMPLIFIED MODEL OF HYPOXIC INJURY IN PRIMARY CULTURED RAT HEPATOCYTES

Tomoo Kamiya; A-Hon Kwon; Toshiki Kanemaki; Yoichi Matsui; Shouji Uetsuji; Tadayoshi Okumura; Yasuo Kamiyama

SummaryThe Anaeropack system for cell culture, which was originally designed for the growth of anaerobic bacteria, was used to produce a hypoxic atmosphere for cultured hepatocytes. We measured changes in the oxygen and carbon dioxide concentrations and the atmospheric temperature in an airtight jar. We also measured changes in the pH of the medium during hypoxia to assess the accuracy of this system. Moreover, we used three durations (2, 3, and 4 h) of hypoxia and 8 h of reoxygenation in cultured rat hepatocytes, and then measured the lactate dehydrogenase (LDH), ketone body concentration (acetoacetate + β-hydroxybutyrate), and the ketone body ratio (KBR: acetoacetate/β-hydroxybutyrate) in the medium in order to assess the suitability of this system as a model for reperfusion following liver ischemia. The oxygen concentration dropped to 1% or less within 1 h. The concentration of carbon dioxide rose to about 5% at 30 min after the induction of the hypoxic conditions, and was maintained at this level for 5 h. No effect of the reaction heat produced by the oxygen absorbent in the jar was recognized. The extent of cell injury produced by changing the hypoxic parameters was satisfactorily reflected by the KBR, the ketone body concentration, and the LDH activity released into the medium. Because this model can duplicate the conditions of the hepatocytes during revascularization following ischemic liver, and the Anaeropack system for cell culture is easy to manipulate, it seems suitable for the experimental study of hypoxic injury and revascularization in vitro.


Nutrition and Cancer | 2008

Immunological effect of active hexose correlated compound (AHCC) in healthy volunteers: a double-blind, placebo-controlled trial.

Naoyoshi Terakawa; Yoichi Matsui; Sohei Satoi; Hiroaki Yanagimoto; Kanji Takahashi; Tomohisa Yamamoto; Jun Yamao; Soichiro Takai; A-Hon Kwon; Yasuo Kamiyama

The aim of this study was to evaluate the effects of active hexose correlated compound (AHCC) intake on immune responses by investigating the number and function of circulating dendritic cells (DCs) in healthy volunteers. Twenty-one healthy volunteers were randomized to receive placebo or AHCC at 3.0 g/day for 4 wk. The number of circulating cluster of differentiation (CD)11c+ DCs (DC1) and CD11c− DCs (DC2) were measured. Allogeneic mixed-leukocyte reaction (MLR) was performed. Natural killer (NK) cell activity and the proliferative response of T lymphocytes toward mitogen (phytohemagglutinin [PHA]) were measured. We also measured cytokine production stimulated by lipopolysaccharide [interleukin (IL)-2, IL-4, IL-6, IL-10, interferon gamma-γ, tumor necrosis factor-α). The AHCC group (n = 10) after AHCC intake had a significantly higher number of total DCs compared to that at baseline and values from control subjects (n = 11). The number of DC1s in the AHCC group after intake was significantly higher than at baseline. DC2s in the AHCC group were significantly increased in comparison with controls. The MLR in the AHCC group was significantly increased compared to controls. No significant differences in PHA, NK cell activity, and cytokine production were found between groups. AHCC intake resulted in the increased number of DCs and function of DC1s, which have a role in specific immunity.

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Sohei Satoi

Kansai Medical University

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A-Hon Kwon

Kansai Medical University

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Satoshi Hirooka

Kansai Medical University

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Yasuo Kamiyama

Kansai Medical University

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So Yamaki

Kansai Medical University

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Masaki Kaibori

Kansai Medical University

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