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Dive into the research topics where Shinichi Ohba is active.

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Featured researches published by Shinichi Ohba.


Journal of Oral Pathology & Medicine | 2010

Overexpression of GLUT-1 in the invasion front is associated with depth of oral squamous cell carcinoma and prognosis

Shinichi Ohba; Hiroaki Fujii; Shin Ito; Mitsuhisa Fujimaki; Fumihiko Matsumoto; Masayuki Furukawa; Junkichi Yokoyama; Takeshi Kusunoki; Katsuhisa Ikeda; Okio Hino

OBJECT Malignant cells show increased uptake, which is considered to be facilitated by glucose transporters (GLUTs). Increased GLUT-1 expression has been reported in many human cancers. We hypothesized that a oral squamous cell carcinoma, characterized by high frequency of lymph node metastasis, distant metastasis or local recurrences, was associated with GLUT-1 overexpression in invasion front. METHODS GLUT-1 immunostaining in invasion front was studied on 24 oral squamous cell carcinomas, and revealed the correlation with the clinical characteristics. RESULT The analysis showed that all oral squamous cell carcinoma patients and GLUT-1 expression correlated the depth of the tumors (P = 0.023 < 0.05). Furthermore the survival of patients who had overexpression of invasion front was significant shorter than that of patients with GLUT-1 weakly positive (P = 0.046 < 0.05). No significant association was noted between GLUT-1 immunostaining and either age, gender, subsites, tumor size, or lymph node status. CONCLUSION The present study shows that GLUT-1 served as a marker indicating that tumors with deep invasion tended to result in a worse prognosis in patients due to either lymph node metastasis, a recurrence of the primary lesion or distant metastasis.


OncoTargets and Therapy | 2013

A feasibility study of NIR fluorescent image-guided surgery in head and neck cancer based on the assessment of optimum surgical time as revealed through dynamic imaging

Junkichi Yokoyama; Mitsuhisa Fujimaki; Shinichi Ohba; Takashi Anzai; Ryota Yoshii; Shin Ito; Masataka Kojima; Katsuhisa Ikeda

Background In order to minimize surgical stress and preserve organs, endoscopic or robotic surgery is often performed when conducting head and neck surgery. However, it is impossible to physically touch tumors or to observe diffusely invaded deep organs through the procedure of endoscopic or robotic surgery. In order to visualize and safely resect tumors even in these cases, we propose using an indocyanine green (ICG) fluorescence method for navigation surgery in head and neck cancer. Objective To determine the optimum surgical time for tumor resection after the administration of ICG based on the investigation of dynamic ICG fluorescence imaging. Methods Nine patients underwent dynamic ICG fluorescence imaging for 360 minutes, assessing tumor visibility at 10, 30, 60, 120, 180, and 360 minutes. All cases were scored according to near-infrared (NIR) fluorescence imaging visibility scored from 0 to 5. Results Dynamic NIR fluorescence imaging under the HyperEye Medical System indicated that the greatest contrast in fluorescent images between tumor and normal tissue could be observed from 30 minutes to 1 hour after the administration of ICG. The optimum surgical time was determined to be between 30 minutes to 2 hours after ICG injection. These findings are particularly useful for detection and safe resection of tumors invading the parapharyngeal space. Conclusion ICG fluorescence imaging is effective for the detection of head and neck cancer. Preliminary findings suggest that the optimum timing for surgery is from 30 minutes to 2 hours after the ICG injection.


Head & Neck Oncology | 2011

A novel approach to translymphatic chemotherapy targeting sentinel lymph nodes of patients with oral cancer using intra-arterial chemotherapy - preliminary study

Junkichi Yokoyama; Shin Ito; Shinichi Ohba; Mitsuhisa Fujimaki; Katsuhisa Ikeda

BackgroundRecent progress in ICG (indocyanine green) fluorescence imaging has provided a means by which we can detect sentinel lymph nodes (SLNs) without the risk of exposing patients to radiation. Neck metastasis is the most significant prognostic factor. It is imperative that early metastasis can be controlled. Intra-arterial chemotherapy is performed in order to preserve organs and to improve prognosis when treating oral cancer.ObjectiveEvaluate translymphatic chemotherapy targeting SLNs in patients with oral cancer using intra-arterial chemotherapy. Evaluation will be carried out through the measurement of CDDP concentrations in SLNs.MethodsFive patients with tongue cancer (T3N0M0) were treated by intra-arterial chemotherapy as neoadjuvant chemotherapy from November 2010 to June 2011. After a week of chemotherapy, patients underwent surgical treatment including the partial resection of the tongue and neck dissection. Intra-arterial chemotherapy was administered at 50 mg/m2 of CDDP either one or two times weekly. 5 mg of ICG was administered to the lingual artery at the beginning of surgery. SLNs were detected using ICG fluorescence imaging. 0.1 g of SLNs and non-SLNs were resected in order to measure CDDP concentrations. The rests of each of the SLNs were examined intraoperatively by routine frozen pathological examination. SLNs were also identified using radioactive injection the day prior to surgery.ResultsThe mean CDDP concentrations in the SLNs and non-SLNs were 1.2 μg/g and 0.35 μg/g, respectively. Our intra- arterial infusion revealed that all metastatic lymph nodes, including SLNs, were without false negative SLNs. However, of 7 metastatic lymph nodes, one was not identified by means of conventional method.ConclusionOur findings verified the possibility that intra-arterial chemotherapy may be effective not only for organ preservation therapy, but also efficient in translymphatic chemotherapy targeting SLNs in patients with oral cancer through the use of ICG fluorescence imaging.


Auris Nasus Larynx | 2009

A case report of metastasizing myoepithelial carcinoma of the parotid gland arising in a recurrent pleomorphic adenoma

Shinichi Ohba; Masato Fujimori; Shin Ito; Fumihiko Matsumoto; Masateru Hata; Hiroyuki Takayanagi; Ryo Wada; Katsuhisa Ikeda

Myoepithelial carcinoma, arising in a recurrent or in a pre-existing pleomorphic adenoma of the parotid gland is an extremely rare cancer. We herein report the case of myoepithelial carcinoma occurring in a recurrent pleomorphic adenoma, which showed a high metastatic potential. A 53-year-old male, who had undergone a superficial parotidectomy of the pleomorphic adenoma 2 years previously, presented with recurrent parotid swelling and with multiple coin lesions in the lung. A total parotidectomy and a thoracoscopic biopsy of the lung lesion revealed both lesions to be myoepithelial carcinoma. The patient died about 12 months later despite undergoing intensive chemotherapy.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2016

Significant preservation of swallowing function in chemoradiotherapy for advanced head and neck cancer by prophylactic swallowing exercise

Shinichi Ohba; Junkichi Yokoyama; Masataka Kojima; Mitsuhisa Fujimaki; Takashi Anzai; Hiroaki Komatsu; Katsuhisa Ikeda

Dysphagia is a serious complication of chemoradiotherapy (CRT) in patients with head and neck cancer. Approximately 20% to 30% of patients who have dysphagia require feeding tubes. The purpose of this study was to evaluate the impact of prophylactic swallowing exercises on swallowing function.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2015

Relationship between insulin-like growth factor-1 receptor and human papillomavirus in patients with oropharyngeal cancer

Fumihiko Matsumoto; Mitsuhisa Fujimaki; Shinichi Ohba; Masataka Kojima; Junkichi Yokoyama; Katsuhisa Ikeda

Human papillomavirus (HPV)‐positive oropharyngeal squamous cell carcinoma (SCC) is associated with better prognosis than HPV‐negative oropharyngeal SCC. The purpose of this study was to assess the expression of insulin‐like growth factor‐1 receptor (IGF‐1R) in patients with oropharyngeal SCC, its relationship to HPV status and various clinical parameters, and its relationship with clinical outcome.


Case reports in pathology | 2015

Cytological Features of Mammary Analogue Secretory Carcinoma of the Parotid Gland in a 15-Year-Old Girl: A Case Report with Review of the Literature

Takako Inaba; Yuki Fukumura; Tsuyoshi Saito; Junkichi Yokoyama; Shinichi Ohba; Atsushi Arakawa; Takashi Yao

Mammary analogue secretory carcinoma (MASC) is a recently recognized tumor of salivary glands characterized by the ETV6-NTRK3 fusion gene. This tumor is very rare in children and adolescents. We report a case of MASC in a 15-year-old girl, the fifth youngest case so far reported. The patient complained of a left infra-auricular mass that gradually enlarged for a year. Fine-needle aspiration cytology/imprint cytology showed individual tumor cells that had faintly eosinophilic granular cytoplasm with secretion granules sometimes seen adjacent to the tumor cells. These cytological features overlapped between those of zymogen granule-poor acinic cell carcinoma (AciCC) and MASC. In addition to the case report, we present a review of the related literature with a focus on the cytological features of MASC. The differential diagnostic clues are also discussed.


World Journal of Surgical Oncology | 2012

Problems of primary T-cell lymphoma of the thyroid gland -A case report

Junkichi Yokoyama; Shin Ito; Shinichi Ohba; Mitsuhisa Fujimaki; Eriko Sato; Norio Komatsu; Katsuhisa Ikeda; Makoto Hanaguri

In the following report we discuss a very rare case of malignant T-cell lymphoma of the thyroid gland that developed in a 70-year-old woman with a past history of hypothyroidism due to chronic thyroiditis. The chief complaint was a rapidly growing neck mass. CT and ultrasonographic examination revealed a diffuse large thyroid gland without a nodule extending up to 13 cm. Although presence of abnormal lymphoid cells in the peripheral blood was not found, the sIL-2 Receptor antibody and thyroglobulin measured as high as 970 U/ml and 600 ng/mL respectively. Fine needle aspiration cytology diagnosed chronic thyroiditis. A preoperative diagnosis of suspicious malignant lymphoma of the thyroid gland accompanied by Hashimoto’s thyroiditis was made, and a right hemithyroidectomy was performed to definite diagnosis. Histological examination revealed diffuse small lymphocytic infiltration in the thyroid gland associated with Hashimoto’s thyroiditis. Immunohistochemical examination showed that the small lymphocytes were positive for T-cell markers with CD3 and CD45RO. The pathological diagnosis was chronic thyroiditis with atypical lymphocytes infiltration. However, Southern blot analysis of tumor specimens revealed only a monoclonal T-cell receptor gene rearrangement. Finally, peripheral T cell lymphoma was diagnosed. Therefore, the left hemithyroidectomy was also performed one month later. No adjuvant therapy was performed due to the tumor stage and its subtype. The patient is well with no recurrence or metastasis 22 months after the surgical removal of the thyroid. As malignant T-cell lymphoma of the thyroid gland with Hashimoto’s thyroiditis was difficult to diagnose, gene rearrangement examination needed to be performed concurrently.


Oral Oncology | 2012

Significant improvement in superselective intra-arterial chemotherapy for oral cancer by using indocyanine green fluorescence

Shinichi Ohba; Junkichi Yokoyama; Mitsuhisa Fujimaki; Shin Ito; Masataka Kojima; Keigo Shimoji; Katsuhisa Ikeda

BACKGROUND Recent advances in indocyanine green (ICG) fluorescence imaging have enabled the visualization of the blood supply to tissues. For advanced head and neck cancer, intra-arterial chemotherapy has been applied for organ preservation and improvement of the prognosis. To identify the tumor-feeding artery, through which the intra-arterial chemotherapy should be administered, CT angiography has been shown to be useful. However, the precise evaluation for oral cancer patients depends on the oral environment, that is, whether they have been treated with dental metal. OBJECTIVES To assess the feasibility of the ICG fluorescence technique during intra-arterial chemotherapy for advanced oral cancer. MATERIAL AND METHOD Twenty-five patients with oral cancer who were treated by intra-arterial chemotherapy were included in this study. Conventional CT angiography followed by 5mg of ICG injection was performed to confirm the areas in which the drug had dispersed. Intra-arterial chemotherapy was administered at 75 mg/m(2) of CDDP. Additional information about the arteries feeding the tumors provided by ICG was evaluated. RESULTS Out of 25 cases, in 15 (56%) the blood supply to the cancer was clearly detected by CT angiography. Using the infrared ICG evaluation, the blood supply to the tumor was confirmed easily in all cases. The information obtained from fluorescence imaging was helpful for making decisions concerning the administration of chemo-agents for oral cancers. CONCLUSION ICG fluorescence imaging during intra-arterial chemotherapy compensated for the deficiencies of CT angiography, especially for oral cancer. ICG fluorescence provided us clearer and more useful information about the feeders to tumors.


Auris Nasus Larynx | 2009

Biopsy of cervical lymph node

Fumihiko Matsumoto; Shin Itoh; Shinichi Ohba; Hidenori Yokoi; Masayuki Furukawa; Katsuhisa Ikeda

OBJECTIVE This report examines 60 non-cancer patients who underwent a cervical lymph node biopsy, and discusses the value of the cervical lymph node biopsy as a diagnostic tool. METHODS Sixty patients with cervical lymph node enlargement who had lymph node biopsies at the Juntendo University between 2004 and 2007 were examined. The clinical parameters including age, size of the lymph node, white blood cell (WBC), C reactive protein (CRP), lactate dehydrase (LDH), soluble interleukin-2 receptor (sIL-2r) were measured at initial examination. Fine needle aspiration cytology was carried out in all patients. The patients were divided into 2 groups, including the malignant lymphoma (ML) group and the benign disease group. These groups were compared based on the patients clinical parameters. RESULTS Serum levels of LDH, sIL-2r, age and lymph node size in the ML group were significantly higher than in the benign group. WBC and CRP showed no significant differences. Simple regression analysis showed that there are correlation between the size of enlargement lymph node and serum levels of LDH and sIL-2r in ML group. CONCLUSION The results of this study suggest that a biopsy should be considered early to patients with an advanced age, large swollen lymph nodes or high levels of serum sIL-2r or LDH.

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