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Dive into the research topics where Kenji Tani is active.

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Featured researches published by Kenji Tani.


Tissue Engineering Part B-reviews | 2014

Status and prospects of liver cirrhosis treatment by using bone marrow-derived cells and mesenchymal cells.

Shuji Terai; Taro Takami; Naoki Yamamoto; Koichi Fujisawa; Tsuyoshi Ishikawa; Yohei Urata; Haruko Tanimoto; Takuya Iwamoto; Yuko Mizunaga; Takashi Matsuda; Oono T; Marumoto M; Guzel Burganova; Fernando Quintanilha L; Isao Hidaka; Yoshio Marumoto; Issei Saeki; Kouichi Uchida; Tokiwa Yamasaki; Kenji Tani; Yasuho Taura; Yasuhiko Fujii; Hiroshi Nishina; Kohsuke Okita; Isao Sakaida

In 2003, we started autologous bone marrow cell infusion (ABMi) therapy for treating liver cirrhosis. ABMi therapy uses 400 mL of autologous bone marrow obtained under general anesthesia and infused mononuclear cells from the peripheral vein. The clinical study expanded and we treated liver cirrhosis induced by HCV and HBV infection and alcohol consumption. We found that the ABMi therapy was effective for cirrhosis patients and now we are treating patients with combined HIV and HCV infection and with metabolic syndrome-induced liver cirrhosis. Currently, to substantiate our findings that liver cirrhosis can be successfully treated by the ABMi therapy, we are conducting randomized multicenter clinical studies designated Advanced medical technology B for HCV-related liver cirrhosis in Japan. On the basis of our clinical study, we developed a proof-of-concept showing that infusion of bone marrow cells (BMCs) improved liver fibrosis and sequentially activated proliferation of hepatic progenitor cells and hepatocytes, further promoting restoration of liver functions. To treat patients with severe forms of liver cirrhosis, we continued translational research to develop less invasive therapies by using mesenchymal stem cells derived from bone marrow. We obtained a small quantity of BMCs under local anesthesia and expanded them into mesenchymal stem cells that will then be used for treating cirrhosis. In this review, we present our strategy to apply the results of our laboratory research to clinical studies.


Research in Veterinary Science | 2010

Fluconazole decreases cyclosporine dosage in renal transplanted dogs.

Masaaki Katayama; Hiroyuki Igarashi; Kazuhiro Fukai; Kenji Tani; Yutaka Momota; Hiroaki Kamishina; Masahiro Tagawa

The effect of fluconazole (Fcz) on the cyclosporine (CsA) dosage was investigated in renal transplanted dogs receiving CsA-based immunosuppressive therapy. Initially, CsA was administered orally twice daily to raise the blood trough level between 400 and 600 ng/ml. After the addition of Fcz, the CsA dosage was adjusted to maintain its therapeutic blood concentration. Fcz significantly decreased CsA dosage in both normal and renal transplanted dogs, but a higher dosage of CsA was needed in renal transplanted dogs. In conclusion, Fcz decreases required CsA dosage and thereby reduces the cost of immunosuppressive therapy in canine renal transplantation.


Indoor and Built Environment | 2017

Prediction of convective heat transfer coefficients for the upper respiratory tracts of rat, dog, monkey, and humans

Kazuhide Ito; Koki Mitsumune; Kazuki Kuga; Nguyen Lu Phuong; Kenji Tani; Kiao Inthavong

In vivo studies involving mammal surrogate models for toxicology studies have restrictions related to animal protection and ethics. Computer models, i.e., in silico models, have great potential to contribute towards essential understanding of heat and mass transfer phenomena in respiratory tracts in place of in vivo and in vitro studies. Here, we developed numerical upper airway models of a rat, a dog, a monkey, and two humans by using computed tomography data and then applied computational fluid dynamics analysis. Convective heat transfer coefficients were precisely analysed as a function of breathing airflow rate. Based on the computational fluid dynamics simulation results, the correlations between Nusselt (Nu) number and the product of the Reynolds (Re) and Prandtl (Pr) numbers were summarized. The heat transfer efficiency (order of hc and correlation of Nu and RePr) in the upper airway of the dog seems to match those of the human models. On the other hand, the results for the rat and monkey showed clear differences compared with those of human models. The identified fundamental qualities of convective heat transfer phenomena in airways for rats, dogs, monkeys, and humans, have enabled discussions about quantitative differences of heat and mass transfer efficiency between different animals/species.


Veterinary Research Communications | 2013

Characterization of neuron-like cells derived from canine bone marrow stromal cells

Yasutaka Oda; Kenji Tani; Toshitaka Kanei; Tomoya Haraguchi; Kazuhito Itamoto; Hiroshi Nakazawa; Yasuho Taura

Regenerative therapy using bone marrow stromal cells (BMSCs) has begun to be clinically applied in humans and dogs for neurological disorders such as spinal cord injury. Under appropriate conditions in vitro, BMSCs differentiate into neuronal cells, which may improve the effects of regenerative therapy. In this study, we evaluated canine neuron-like cells (NLCs) derived from BMSCs. We speculated on their suitability for neuro-transplantation from the point of view of their morphological features, long-term viability, abundant availability, and ability to be subcultured. Canine NLCs were differentiated as follows: third-passage BMSCs were maintained in pre-induction medium containing 2-mercaptoethanol and dimethylsulfoxide for 5xa0h, and then cells were transferred to neuronal induction medium containing fetal bovine serum, basic fibroblast growth factor, epidermal growth factor, dibutyryl cyclic AMP, and isobutylmethylxanthine for 7 or 14xa0days. Canine NLCs fulfilled the transplantation criteria and expressed markers of both immature neurons (nestin, 84.7xa0%) and mature neuronal cells (microtubule-associated protein-2, 95.7xa0%; βIII-tubulin protein, 12.9xa0%; glial fibrillary acidic protein, 9.2xa0%). These results suggest that canine BMSCs can be induced to differentiate into neuronal cells and may be suitable for neuro-transplantation. This study may provide information for improving cellular therapy for neurological diseases.


World Journal of Gastroenterology | 2016

Effects of an oral iron chelator, deferasirox, on advanced hepatocellular carcinoma

Issei Saeki; Naoki Yamamoto; Takahiro Yamasaki; Taro Takami; Masaki Maeda; Koichi Fujisawa; Takuya Iwamoto; Toshihiko Matsumoto; Isao Hidaka; Tsuyoshi Ishikawa; Koichi Uchida; Kenji Tani; Isao Sakaida

AIM To evaluate the inhibitory effects of deferasirox (DFX) against hepatocellular carcinoma (HCC) through basic and clinical studies. METHODS In the basic study, the effect of DFX was investigated in three hepatoma cell lines (HepG2, Hep3B, and Huh7), as well as in an N-nitrosodiethylamine-induced murine HCC model. In the clinical study, six advanced HCC patients refractory to chemotherapy were enrolled. The initial dose of DFX was 10 mg/kg per day and was increased by 10 mg/kg per day every week, until the maximum dose of 30 mg/kg per day. The duration of a single course of DFX therapy was 28 consecutive days. In the event of dose-limiting toxicity (according to the Common Terminology Criteria for Adverse Events v.4.0), DFX dose was reduced. RESULTS Administration of DFX inhibited the proliferation of hepatoma cell lines and induced the activation of caspase-3 in a dose-dependent manner in vitro. In the murine model, DFX treatment significantly suppressed the development of liver tumors (P < 0.01), and significantly upregulated the mRNA expression levels of hepcidin (P < 0.05), transferrin receptor 1 (P < 0.05), and hypoxia inducible factor-1α (P < 0.05) in both tumor and non-tumor tissues, compared with control mice. In the clinical study, anorexia and elevated serum creatinine were observed in four and all six patients, respectively. However, reduction in DFX dose led to decrease in serum creatinine levels in all patients. After the first course of DFX, one patient discontinued the therapy. We assessed the tumor response in the remaining five patients; one patient exhibited stable disease, while four patients exhibited progressive disease. The one-year survival rate of the six patients was 17%. CONCLUSION We demonstrated that DFX inhibited HCC in the basic study, but not in the clinical study due to dose-limiting toxicities.


Journal of Veterinary Medical Science | 2015

Anatomical evaluation of hepatic vascular system in healthy beagles using X-ray contrast computed tomography

Yasuhisa Oishi; Kenji Tani; Hiroshi Nakazawa; Kazuhito Itamoto; Tomoya Haraguchi; Yasuho Taura

Liver contrast X-ray computed tomography (CT) has been used for evaluation of hepatic vessels for liver transplantation, liver lobectomy, interventional radiology and diagnosis of hepatocellular carcinoma in humans. However, there remains scant available anatomical information on normal hepatic vessels in the veterinary field. In this study, visualization of hepatic vessels was evaluated in 32 normal beagle dogs by X-ray contrast CT using triple phase images. The following hepatic vessels were clearly visualized: arterial, portal and hepatic veins. With regards to the running patterns of the portal vein and hepatic vein, there were no significant differences between the dogs. However, the hepatic artery exhibited some differences in each dog. In particular, the hepatic artery of the quadrate lobe and the right lateral lobe had many running patterns. The results of the present study could be useful for veterinary diagnosis, surgery and interventional radiology.


Journal of Veterinary Medical Science | 2014

Canine Bone Marrow Stromal Cells Promote Functional Recovery in Mice with Spinal Cord Injury

Yasutaka Oda; Kenji Tani; Yusuke Asari; Luiz Fernando Quintanilha; Tomoya Haraguchi; Yutaka Momota; Masaaki Katayama; Kazuhito Itamoto; Hiroshi Nakazawa; Yasuho Taura

ABSTRACT Regenerative therapy has begun to be clinically applied in humans and dogs to treat neurological disorders, such as spinal cord injury (SCI). Here, we show the therapeutic potential of transplantation of cultured canine bone marrow stromal cells (BMSCs) into mice with SCI. Canine BMSC transplantation therapy was performed, immediately after the spinal cord was injured. Canine BMSC therapy enhanced functional recovery of the hind limbs in mice with SCI. Nestin-positive cells were observed only in the lesion of mice with SCI that received BMSCs. These results suggest that canine BMSCs promote functional recovery in mice with SCI and that migration of nestin-positive cells may contribute to the efficacy of the BMSC treatment.


Veterinary Dermatology | 2016

The modified corneocyte surface area measurement as an index of epidermal barrier properties: inverse correlation with transepidermal water loss.

Yutaka Momota; Kenichiro Shimada; Azusa Noguchi; Akio Saito; Satoshi Nozawa; Ayaka Niina; Kenji Tani; Daigo Azakami; Katsumi Ishioka; Toshinori Sako

BACKGROUNDnCorneocyte surface area (CSA) is as established parameter for skin barrier function in humans. Measurement of canine CSA has been previously reported but has not been validated.nnnHYPOTHESIS/OBJECTIVESnThe aim of this study was to evaluate the validity of CSA as a barrier function parameter in dogs.nnnANIMALSnSix clinically normal beagle dogs.nnnMETHODSnCSA was measured and compared with transepidermal water loss (TEWL) using sequential tape stripping of the stratum corneum as a model of acute barrier disruption. Then, CSA and TEWL were measured at four anatomical sites (groin, lower back, nasal bridge and pinna). The correlation between the two indices was also evaluated.nnnRESULTSnFrom the results of sequential tape stripping, CSA values gradually decreased with increasing number of tape strippings. The CSA values were inversely correlated with the TEWL ones. The two indices at different sites were variable and were strongly correlated.nnnCONCLUSIONS AND CLINICAL IMPORTANCEnCanine CSA was demonstrated to be a useful parameter for the canine skin barrier function. The results from the anatomical sites imply that the cephalic sites (nasal bridge and pinna) were lower than others in skin barrier function.


Journal of Veterinary Medical Science | 2017

Comparison of postoperative pain and inflammation reaction in dogs undergoing preventive laparoscopic-assisted and incisional gastropexy

Tomoya Haraguchi; Shiho Kimura; Harumichi Itoh; Shimpei Nishikawa; Masato Hiyama; Kenji Tani; Toshie Iseri; Yoshiki Itoh; Munekazu Nakaichi; Yasuho Taura; Kazuhito Itamoto

This study compared the effects of postoperative pain and inflammation reaction after preventive laparoscopic-assisted gastropexy (LAG) and incisional gastropexy (IG) in 10 clinically normal Beagles. Surgical time, incision length, visual analog scale (VAS) score, University of Melbourne Pain Scale (UMPS) score, and plasma C-reactive protein (CRP), plasma cortisol (COR), and serum interleukin-6 (IL-6) levels were evaluated. The VAS and UMPS scores and COR and IL-6 levels were recorded at 0.5, 1, 2, 4, 8, 12, 18 and 24 hr after surgery. CRP level was recorded at 12, 24 and 48 hr after surgery. The VAS and UMPS scores showed no significant intergroup differences. Compared to IG, LAG had significantly lower surgical time (45 ± 9.91 min vs 64 ± 5.30 min; P<0.05), incision length (46 ± 8.21 mm vs 129 ± 19.49 mm; P<0.05), CRP level (12 hr after surgery; 4.58 ± 1.58 mg/dl vs 12.4 ± 1.34 mg/dl; P<0.01), and COR level (1 hr after surgery; 10.79 ± 3.07 µg/dl vs 15.9 ± 3.77 µg/dl; P<0.05). IL-6 levels showed no significant intergroup differences at any time point. However, LAG resulted in lower IL-6 levels than did IG at all postoperative time points. Neither procedure resulted in significant surgical complications. LAG produced lower surgical stress than did IG, suggesting that LAG is a safe, minimally invasive, and highly useful technique for preventing canine gastric dilatation-volvulus. Nevertheless, since this study used experimental models, its usefulness should be evaluated in future cases.


Journal of Veterinary Medical Science | 2017

Aldehyde dehydrogenase activity identifies a subpopulation of canine adipose-derived stem cells with higher differentiation potential

Harumichi Itoh; Shimpei Nishikawa; Tomoya Haraguchi; Yu Arikawa; Masato Hiyama; Shotaro Eto; Toshie Iseri; Yoshiki Itoh; Kenji Tani; Munekazu Nakaichi; Yasuho Taura; Kazuhito Itamoto

Adipose-derived stem cells (ADSCs) are abundant and readily obtained, and have been studied for their clinical applicability in regenerative medicine. Some surface antigens have been identified as markers of different ADSC subpopulations in mice and humans. However, it is unclear whether functionally distinct subpopulations exist in dogs. To address this issue, we evaluated aldehyde dehydrogenase (ALDH) activity—a widely used stem cell marker in mice and humans—by flow cytometry. Approximately 20% of bulk ADSCs showed high ALDH activity. Compared to cells with low activity (ALDHLo), the high-activity (ALDHHi) subpopulation exhibited a higher capacity for adipogenic and osteogenic differentiation. This is the first report of distinct ADSC subpopulations in dogs that differ in terms of adipogenic and osteogenic differentiation potential.

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Yutaka Momota

Nippon Veterinary and Life Science University

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