Naoaki Rikihisa
Chiba University
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Publication
Featured researches published by Naoaki Rikihisa.
Plastic and Reconstructive Surgery | 2013
Shinsuke Akita; Nobuyuki Mitsukawa; Naoaki Rikihisa; Yoshitaka Kubota; Naoko Omori; Akira Mitsuhashi; Shinichi Tate; Makio Shozu; Kaneshige Satoh
Background: Although early diagnosis is important for selecting an effective surgical treatment for secondary lymphedema, an efficient screening test for detecting early-stage lymphedema has not yet been established. Serial changes of lymphatic function before and after lymph node dissection and risk factors for secondary lymphedema are important indicators. Methods: A prospective cohort observational study was conducted with 100 consecutive gynecologic cancer patients who underwent pelvic lymph node dissection. Lymphatic function was assessed by noninvasive lymphography using indocyanine green fluorescence imaging on a routine schedule. Earliest findings after lymphadenectomy and risk factors for lower leg lymphedema were investigated. Results: Atypical transient dermal backflow patterns were observed in an early postoperative period in 50 cases, all of which disappeared within 3 months. Of these patterns, the splash pattern was observed in 31 patients, of which five improved to normal following a natural course. In contrast, the stardust pattern was observed in 27 patients, and none had improved with conservative therapy. Postoperative radiotherapy was a significant risk factor for the stardust pattern. Conclusions: All patients who undergo lymphadenectomy for gynecologic malignancies should be examined for secondary lower extremity lymphedema by qualitative evaluation methods on a routine schedule to determine the earliest possible diagnosis. Because the splash pattern on indocyanine green lymphography is a reversible lymphatic disorder following a natural course, surgical treatments are not recommended. The decision regarding surgical treatment can be made after observing the stardust pattern. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.
Vaccine | 2001
Seiko Saito; Fumie Aosai; Naoaki Rikihisa; Hye-Seong Mun; Kazumi Norose; Mei Chen; Tomoaki Kuroki; Takehide Asano; Takenori Ochiai; Hidekazu Hata; Masaharu Ichinose; Akihiko Yano
Vaccine effects of in vivo gene-vaccinated skin graft were evaluated against Toxoplasma gondii (T. gondii) infection. By using a gene gun, cDNA coding T. gondii SAG1 molecule was intracutaneously vaccinated into C57BL/6 (B6; a susceptible strain), BALB/c (a resistant strain) and (C57BL/6 x BALB/c) F1 (CBF1) mice, and the gene-vaccinated skin of these strains was transplanted to CBF1 mice. Regarding the antibody production against SAG1, CBF1-recipient mice transplanted with the SAG1 gene-vaccinated B6 skin were high responders, whereas CBF1 mice skin grafted with vaccinated skin of both BALB/c and CBF1 mice were low responders. The donor-derived LC/DC migrated to the draining lymph nodes of the recipients from the skin graft within 3 days. The vaccine effect against T. gondii challenge infection was obtained in CBF1 mice which received the skin graft of the SAG1 gene-vaccinated BALB/c mice.
Journal of Plastic Reconstructive and Aesthetic Surgery | 2012
Yoshitaka Kubota; Tomoaki Kuroki; Shinsuke Akita; Tomoe Koizumi; Masakazu Hasegawa; Naoaki Rikihisa; Nobuyuki Mitsukawa; Kaneshige Satoh
BACKGROUND Titanium-based plates used to repair facial fractures are sometimes removed despite their high biocompatibility. Local discomfort can lead to plate removal surgery. Local discomfort may differ according to patient characteristics, tissue properties and plate thickness; however, little is known about the relationship between these conditions and plate removal. METHODS We performed a hospital-based, retrospective cohort study of patients who underwent internal fixation for facial or frontal bone fracture. To identify factors associated with plate removal, we used multivariate logistic regression models. RESULTS Data from 138 patients were analysed. All plates were made of commercially pure titanium, and all screws were made of titanium, 6% aluminium and 4% vanadium alloy. Plate thickness was 1.2 mm or 0.6 mm. Among plate locations, the frontozygomatic suture showed the highest percentage of complications (84%, 86 of 102 patients). The majority consisted of palpability and visibility. In patients who underwent plate removal (n = 96), all plates and screws were removed successfully. All plate-related complications were resolved after plate removal. No complications were introduced by plate removal. Plates 1.2 mm in thickness on the frontozygomatic suture had a relative risk of complications 2.48 times (95% confidence interval, 1.13-5.43) that of plates 0.6 mm in thickness. By multivariate analysis, the presence of plates on the frontozygomatic suture was a significant and independent risk factor for removal. Patients with plates on the frontozygomatic suture had a risk of plate removal 3.95 times (95% confidence interval, 1.55-10.07; P < 0.01) that of patients without plates on the frontozygomatic suture. CONCLUSION Plates on the frontozygomatic suture have a high rate of complications. Thick plates increase these risks. Patients with plates on the frontozygomatic suture are more likely to undergo plate removal surgery than patients without plates on the frontozygomatic suture.
European Journal of Clinical Investigation | 2008
D. Kuramochi; Hiroyuki Unoki; Hideaki Bujo; Yoshitaka Kubota; Meizi Jiang; Naoaki Rikihisa; Akikazu Udagawa; Shinya Yoshimoto; Masaharu Ichinose; Yasushi Saito
Background Fat tissue is a common material for autologous transplantation in plastic and reconstructive surgery. Basic fibroblast growth factor (bFGF) ameliorates the fat graft survival. A transplantation model has shown the gene expression of matrix metalloproteinases (MMPs) to increase in adipocytes. The aim of this study is to investigate the role of MMPs in the amelioration of survival by bFGF.
Biochemical and Biophysical Research Communications | 2008
Yoshitaka Kubota; Hiroyuki Unoki; Hideaki Bujo; Naoaki Rikihisa; Akikazu Udagawa; Shinya Yoshimoto; Masaharu Ichinose; Yasushi Saito
The increased population of TLR2/TNF-alpha co-expressing adipocytes is associated with the development of insulin resistance. We have herein shown the significance of low-dose growth hormone (GH) supplementation for the regulation of TLR2 and TNF-alpha expressions in visceral fat using different kinds of mouse models fed with a high-fat diet. Low-dose GH supplementation reduced the increased population of TLR2/TNF-alpha co-expressing adipocytes in high-fat fed mice. The neutralization of IGF-1 abolished the effect of GH supplementation on the TLR2 expression using GH-overexpressing mice. IGF-1, but not GH, inhibited the FFA-induced TLR2 and TNF-alpha expression in 3T3-L1 cells. Finally, low-dose GH supplementation reduced the TLR2 expression without an obvious change in the visceral fat volume in ob/ob mice. These results indicate that low-dose GH supplementation possibly inhibits the high-fat induced change of the adipocytes to TLR2/TNF-alpha co-expressing cells through the action of IGF-1.
Microsurgery | 2014
Shinsuke Akita; Nobuyuki Mitsukawa; Naoaki Rikihisa; Motone Kuriyama; Yoshitaka Kubota; Masakazu Hasegawa; Tomoe Koizumi; Tatsuya Ishigaki; Yuuki Uchida; Kaneshige Satoh
Reconstruction of the great toe defect is difficult. The most distal point of the rotation arc of a retrograde‐flow medial plantar flap is the plantar side of the proximal phalanx. The purpose of this report was to present a new procedure that extends the rotation arc of this flap. Results of anatomic study and application in two patients were presented.
Plastic and Reconstructive Surgery | 2013
Shinsuke Akita; Nobuyuki Mitsukawa; Naoaki Rikihisa; Juni Himeta; Yoshitaka Kubota; Natsuko Shimada; Hideki Tokumoto; Takane Suzuki; Kaneshige Satoh
Background: Reconstruction of intractable ulcers on the lateral malleolus is challenging because affected patients suffer various complications. A lateral supramalleolar flap, nourished by the superficial cutaneous branch of the perforating branch of the peroneal artery, has been described as one of the most reliable methods for reconstructing this difficult region. Although the deep descending branch of the perforating branch of the peroneal artery has a tiny cutaneous perforator, a flap based on this perforator has not been described. Methods: The vascular anatomy of an island flap based on the descending branch perforator of the perforating branch of the peroneal artery was investigated using 20 cadaver legs. Distances from the lateral malleolus and the external diameters were investigated. Based on the anatomical study results, a perforator–based island flap was developed for clinical use and implemented in five cases. Results: The anatomical study revealed the descending branch perforator diameter to be smaller than the superficial cutaneous branch diameter, and the location to be considerably closer to the lateral malleolus. All five island flaps used clinically survived without complications. Conclusions: A new perforator-based island flap of the descending branch of the perforating branch of the peroneal artery for reconstruction of the lateral malleolus was designed. The territory covered by the flap could be enlarged by including the adjacent angiosome area of the superficial cutaneous branch. This flap elevation technique was uncomplicated and sufficiently straightforward to be used for patients at high risk for complications with extended surgical procedures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.
Plastic and Reconstructive Surgery | 2017
Naoaki Rikihisa; Shoji Watanabe; Kaneshige Satoh; Yoshiaki Saito; Hiromi Sakai
Background: The complete removal of port-wine stains has remained challenging. Based on the principle of treating port-wine stains with a dye laser, intravenous injection of artificial red cells (hemoglobin vesicles) immediately before laser treatment might improve the clinical outcome of the therapy. The hemoglobin vesicle injection increases the hemoglobin concentration in microvessels. Photons of dye laser are absorbed by the mixture of red blood cells and this newly added hemoglobin, potentially producing more heat and photocoagulation and, ultimately, necrosis of the endothelial cells effectively. Methods: To confirm the performance of hemoglobin vesicles as a photosensitizer, the authors compared the absorbance of hemoglobin vesicles and human blood against 595-nm wavelength and the temperature increases that occur following dye laser irradiation. Furthermore, the authors investigated the microvessel transformation induced by the hemoglobin vesicle intravenous injection. Finally, the authors investigated the effect of the hemoglobin vesicle on the vascular destruction of dye laser irradiation with chicken wattle. Results: Results show that hemoglobin vesicles have the same absorbance as that of human blood. They produce the same level of heat as human blood after laser irradiation. The hemoglobin vesicle intravenous injection caused dilatation of microvessels in animal models. The dye laser with hemoglobin vesicle can destroy the vessel wall effectively in animal models. Conclusions: Hemoglobin vesicles can function as photosensitizers to destroy the vessel wall. A possible mechanism of pulsed dye laser–resistant port-wine stains is that overly small vessels do not contain sufficient red blood cells. They are therefore poor absorbers/heaters for these lasers. Hemoglobin vesicle combination therapy will improve clinical outcomes of dye laser treatment against such lesions only.
Journal of Plastic Surgery and Hand Surgery | 2011
Shinsuke Akita; Tomoaki Kuroki; Shinya Yoshimoto; Naoaki Rikihisa; Kaneshige Satoh
Abstract We raised thenar island flaps that were supplied by perforators that originated in the superficial palmar arch or the superficial palmar branch of the radial artery for the reconstruction of fingertip defects in eight patients. The flap was so well-vascularised that a large flap with increased mobility could be raised. The donor site was covered with well-vascularised thick tissue, and skin grafting of the donor site was avoided in all cases. No patient developed a complication, and all flaps survived. Functional and cosmetic results of both fingertips and donor sites were excellent. A perforator island flap from the thenar eminence can be raised easily without injuring any digital and palmar arteries. They have a good colour and texture that matches the fingertips and donor site defects on the palm.
Journal of Functional Biomaterials | 2017
Naoaki Rikihisa; Shoji Watanabe; Yoshiaki Saito; Hiromi Sakai
We suggest a novel method that uses artificial blood cells (hemoglobin vesicles, Hb-Vs) as photosensitizers in dye laser treatment (at 595-nm wavelength) for port-wine stains (i.e., capillary malformations presenting as red birthmarks) based on the results of animal experiments. As compared with human red blood cells, Hb-Vs have the same absorbance of 595 nm wavelength light and produce the same level of heat following dye laser irradiation. Small sized Hb-Vs (250 nm) distribute in the plasma phase in blood and tend to flow in the marginal zone of microvessels. Intravenous injections of Hb-Vs caused the dilatation of microvessels, and dye laser treatment with Hb-Vs destroyed the vessel wall effectively. Following the intravenous injection of Hb-Vs, the microvessels contained more Hb that absorbed laser photons and produced heat. This extra Hb tended to flow near the endothelial cells, which were the target of the laser treatment. These attributes of Hb-Vs will potentially contribute to enhancing the efficacy of dye laser treatment for port-wine stains. Hemoglobin is a type of porphyrin. Thus, our proposed treatment may have aspects of photodynamic therapy using porphyrin that leads to a cytotoxicity effect by active oxygen.