Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Akira Ohshima is active.

Publication


Featured researches published by Akira Ohshima.


American Journal of Surgery | 2002

Video-assisted thyroid lobectomy through a small wound in the submandibular area

Hiroyuki Yamashita; Shin Watanabe; Eisuke Koike; Akira Ohshima; Shinya Uchino; Syoji Kuroki; Masao Tanaka; Shiro Noguchi

BACKGROUND Endoscopic thyroidectomy has not gained wide acceptance because of the expertise required, the long operation time, the wide dissection, and the extra cost of specialized instruments. We developed a video-assisted hemithyroidectomy procedure that requires only one small incision at the upper neck. METHODS Hemithyroidectomy was performed through a 25 to 30 mm transverse incision made in the upper lateral neck for the treatment of benign thyroid nodule. No gas or external lift dissection was needed. RESULTS The mean age of 39 patients was 33.8 years. The tumor size ranged from 1.9 to 5.5 cm (mean 3.1 cm). All patients underwent total lobectomy without conversion to traditional cervicotomy. The mean operation time was 56 minutes (range 36 to 90). Follicular adenoma was the final pathologic diagnosis in 25 patients and adenomatous goiter in 14. Transient recurrent laryngeal nerve palsy was seen in 1 patient. CONCLUSIONS Our technique is safe, minimally invasive, less time consuming, and cosmetically excellent.


Japanese Journal of Cancer Research | 1999

Somatic Mutations in RET Exons 12 and 15 in Sporadic Medullary Thyroid Carcinomas: Different Spectrum of Mutations in Sporadic Type from Hereditary Type

Shinya Uchino; Shiro Noguchi; Hiroto Yamashita; Mari Sato; Mitsuo Adachi; Hiroyuki Yamashita; Shin Watanabe; Akira Ohshima; Shoshu Mitsuyama; Toshihide Iwashita; Masahide Takahashi

Germline mutations in the RET proto‐oncogene are responsible for multiple endocrine neoplasia type 2 (MEN 2A and 2B) and familial medullary thyroid carcinoma (FMTC). Point mutations or in‐frame deletions of exons 10, 11, 13, 14 and 16 are associated with sporadic medullary thyroid carcinoma (MTC). To understand further the role of the RET gene in sporadic MTC, we examined mutations in exons 12 and 15 of RET in patients with sporadic MTC. DNAs were extracted from 39 formalin‐fixed tumor tissues and corresponding normal thyroid tissues or peripheral blood leukocytes. DNA sequencing was used to identify mutations in exons 12 and 15 of RET. In this study, one novel somatic mutation was found in exon 12 and five novel mutations or deletions were found in exon 15. Of the patients with mutations, one had an in‐frame 12‐bp deletion (nt. 2625‐2636), one had point mutations in both codons 884 and 908, and the remaining three had point mutations in codons 748, 876 and 901, respectively. Together with our previous identification of somatic mutations in exons 10, 11, 13, 14 and 16, somatic alterations were found in 10 out of 39 (25.6%) sporadic MTCs. There was no association of RET gene mutations with tumor recurrence or prognosis. These results suggest that mutations occur frequently in the RET coding region in addition to the previously reported mutation hot spots, and there is a different spectrum of mutations between sporadic and hereditary MTC.


European Journal of Surgery | 2001

Effect of Combining Ultrasonography and Ultrasound-Guided Fine-Needle Aspiration Biopsy Findings for the Diagnosis of Thyroid Nodules

Eisuke Koike; Hiroyuki Yamashita; Shiro Noguchi; Tsukasa Murakami; Akira Ohshima; Junko Maruta; Hitoshi Kawamoto; Hiroto Yamashita

OBJECTIVE To assess the accuracy of ultrasonography and cytology in predicting malignancy in thyroid nodules. DESIGN Prospective open study. SETTING Thyroid centre, Japan. SUBJECTS 329 nodules in 309 patients examined by a new ultrasound scanner and ultrasound-guided fine-needle aspiration biopsy. INTERVENTIONS Comparison of ultrasonographic, cytological, and combined diagnosis with the histological diagnosis. MAIN OUTCOME MEASURES Sensitivity, specificity, and accuracy of each diagnostic method. RESULTS The sensitivity, specificity, accuracy were 84%, 87%, 85% for cytological diagnosis, and 82%, 91%, and 87% for ultrasonographic diagnosis. By using ultrasonographic diagnosis when cytological specimens were inadequate or gave false negative results, the sensitivity, specificity, and accuracy went up to 89%, 91%, and 90%, respectively. We could not diagnose follicular carcinomas accurately by combined cytology and ultrasonography. CONCLUSION The combination of ultrasonography and cytology improves the accuracy of diagnosis of thyroid nodules, but is less effective with follicular tumours.


World Journal of Surgery | 2005

Intraoperative parathyroid hormone assay in patients with Graves' disease for prediction of postoperative tetany

Taiki Moriyama; Hiroyuki Yamashita; Shiro Noguchi; Yuji Takamatsu; Takahiro Ogawa; Shin Watanabe; Shinya Uchino; Akira Ohshima; Syoji Kuroki; Masao Tanaka

We measured intraoperative parathyroid hormone (IOPTH) levels before and after thyroidectomy in a large group of patients to test whether changes in IOPTH can predict postoperative tetany. Subjects were 111 consecutive patients (94 females and 17 males) with Graves’ disease undergoing subtotal thyroidectomy. Blood samples for IOPTH assay were obtained after anesthesia (basal) and following skin closure (postoperative). Data were compared between patients who developed tetany (n = 9) and those who did not (n = 102). There was no significant difference in sex, age, period of antithyroid drug administration, or the weight of the thyroid between the two groups. The preoperative serum calcium level was significantly lower (p < 0.05) and the basal IOPTH significantly higher (p < 0.05) in the tetany group than in the non-tetany group. The IOPTH level was significantly lower (p < 0.005) and the average percent decrease in IOPTH levels was higher (p < 0.001) in the tetany group than in the non-tetany group. A decrease in IOPTH of more than 70% was shown to be 78% sensitive, 94% specific, and 93% accurate, and it has 78% positive predictive value and 94% negative predictive value for the development of tetany. Our study shows that a postoperative decrease of IOPTH level is the most predictive of postoperative tetany of the clinical risk factors investigated. We recommend IOPTH measurement as an adjunct to postoperative management of patients with Graves’ disease to assist in preventing hypocalcemia and determining the earliest time for safe discharge.


Breast Cancer | 2004

A Case of Breast Cholesterol Granuloma Accompanied by Cancer

Chizu Furuhira; Akira Ohshima; Kazuo Shimada; Syoji Kuroki; Kenji Nakano; Mikimasa Ishikawa; Hidetaka Yamamoto; Masao Tanaka

Cholesterol granuloma of the breast is a very rare benign disease with clinical and imaging features that are often indistinguishable from cancer preoperatively. We report a case of breast cholesterol granuloma accompanied by cancer. The patient was a 78-year-old woman who complained of a lump in her right breast. Mammography and ultrasonography showed a well-circumscribed mass. Fine needle aspiration cytology showed many cholesterol crystals and inflammatory cells without malignancy. With a diagnosis of cholesterol granuloma, tumor extirpation was performed. Histopathologic examination revealed cholesterol granuloma together with breast cancer, and additional partial mastectomy was subsequently performed. It is noted that breast cholesterol granuloma could be accompanied by cancer.


Surgery Today | 2002

Is a bilateral modified radical neck dissection beneficial for patients with papillary thyroid cancer

Akira Ohshima; Hiroyuki Yamashita; Shiro Noguchi; Shinya Uchino; Shin Watanabe; Eisuke Koike; Hiroto Yamashita; Syoji Kuroki; Masao Tanaka

Abstract.Purpose: We previously reported a poor prognosis in papillary thyroid carcinoma patients with recurrence in the contralateral cervical lymph nodes after thyroidectomy and ipsilateral modified radical neck dissection (MRND) with a curative intent. The aim of this study was to investigate whether bilateral MRND improved prognosis in patients at risk for contralateral nodal recurrence. Methods: We retrospectively reviewed the cases of 86 patients with contralateral nodal metastasis who underwent a thyroidectomy with bilateral MRND (group 1) and the cases of 32 patients who suffered contralateral nodal recurrence after a thyroidectomy with ipsilateral MRND (group 2). Results: Although tumor progression was considered similar in patients from groups 1 and 2, group 1 developed fewer distant metastases than group 2 (6.8% vs 31.1%), thus resulting in a lower cancer death rate (5.8% vs 28.1%). Group 1 had a better 10-year survival rate than of group 2 (97.1% vs 83.7%). Conclusion: Bilateral MRND during initial surgical management is thus considered to improve the prognosis of some papillary carcinoma patients at risk for recurrence in the contralateral cervical lymph nodes.


European Journal of Surgery | 2000

Calcium and its regulating hormones in patients with graves disease: sex differences and relation to postoperative tetany.

Hiroyuki Yamashita; Shiro Noguchi; Tukasa Murakami; Shinya Uchino; Shin Watanabe; Akira Ohshima; Hitoshi Kawamoto; Masakatsu Toda; Hiroto Yamashita

OBJECTIVE To find out why female sex is the most important risk factor for tetany, as calcium and bone metabolism may differ between the sexes. DESIGN Prospective study. SETTING Thyroid centre, Japan. PATIENTS AND METHODS 45 men (mean age 35 years, SD 13) and 178 women (mean age 33 years, SD 12) with Graves disease treated by subtotal thyroidectomy. INTERVENTIONS Measurement of serum concentrations of intact parathyroid hormone (iPTH), calcium, electrolytes, 25-hydroxyvitamin D (25 (OH) D), and 1,25-dihydroxyvitamin D (1,25 (OH) 2D). MAIN OUTCOME MEASURES Mean values of these substances, together with reductions in serum calcium concentration, relative youth, increased alkaline phosphatase activity, large goitre, and increased serum TSH binding inhibitory globulin concentration. RESULTS Women had significantly lower calcium concentrations than men (mean (SD) 2.37 (0.13) compared with 2.43 (0.07), p = 0.003). Serum calcium concentrations correlated significantly with concentrations of 25 (OH) D (p < 0.001). 121 of the women (68%) compared with 13 (29%) of men had vitamin D deficiency as defined as 25 (OH) D < 25 nmol/l (p < 0.05). 15 patients (8%) developed tetany postoperatively compared with I man (2%, p = 0.2). CONCLUSION Women with Graves disease are more susceptible to calcium and vitamin D deficiency than men, which may account for the higher incidence of postoperative tetany among women with the disease.


Surgery Today | 1995

Effects of medroxyprogesterone acetate therapy on advanced or recurrent breast cancer and its influences on blood coagulation and the fibrinolytic system

Osahiko Abe; Kazuaki Asaishi; Masaru Izuo; Kohji Enomoto; Hiroki Koyama; Takeshi Tominaga; Yasuo Nomura; Akira Ohshima; Nobuo Aoki; Toshiyasu Tsukada

The effects of medroxyprogesterone acetate (MPA) therapy on advanced or recurrent breast cancer and its influence on blood coagulation and the fibrinolytic system were compared among three different therapy regimens consisting of cyclophosphamide, adriamycin, and 5-fluorouracil (CAF) + MPA and CAF or MPA alone. A clinical response was observed in 42.9% (9/21) of the patients for CAF + MPA, 36.4% (8/22) for CAF and 23.8% (5/21) for MPA alone. No marked thrombosis or its prodromal condition was observed in any group. The effects on the test values for blood coagulation and the fibrinolytic system did not significantly change in the CAF group. However, both AT-III and protein C significantly increased above the normal ranges in the CAF + MPA and MPA groups. Increases in factor X, plasminogen, and α2-plasmin inhibitor/plasmin complex (PIC) and decreases in fibrinogen, tissue plasminogen activator, and D-dimer, were all observed in the MPA and CAF + MPA groups, especially in the MPA group, although these changes remained within the normal ranges. The data indicated that MPA has various influences on blood coagulation and the fibrinolytic system, but these changes did not suggest activation of the blood coagulation system.


Case reports in endocrinology | 2012

A Poor Prognostic Case of Mucoepidermoid Carcinoma of the Thyroid: A Case Report

Koji Shindo; Shinichi Aishima; Masayuki Okido; Akira Ohshima

Mucoepidermoid carcinoma (MEC) of the thyroid is very rare and low-grade indolent neoplasm. In past reports of the thyroid MEC, only seven cases were described as poor prognosis. A 91-year-old woman presented with a rapidly growing mass of the left upper neck. She was followed thyroid papillary carcinoma (PC) without operation for two years. Fine needle aspiration cytology (FNAC) showed undifferentiated cells. Total thyroidectomy and bilateral neck dissection were performed. In pathological findings, the tumor had two areas of MEC and PC. The boundary of them was mixed. She died of multiple lung metastases only after four months from the operation. We report a rare case of thyroid MEC which had an aggressive behavior and poor prognosis. This case is a precious in that thyroid MEC occurred during observation of PC and suggests a possibility of the transformation from PC to MEC.


Archives of Surgery | 2001

Ultrasonographic characteristics of thyroid nodules : Prediction of malignancy

Eisuke Koike; Shiro Noguchi; Hiroyuki Yamashita; Tsukasa Murakami; Akira Ohshima; Hitoshi Kawamoto; Hiroto Yamashita

Collaboration


Dive into the Akira Ohshima's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Shinya Uchino

Fukushima Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge