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Dive into the research topics where Yozo Orita is active.

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Featured researches published by Yozo Orita.


Plastic and Reconstructive Surgery | 1993

Free combined composite flaps using the lateral circumflex femoral system for repair of massive defects of the head and neck regions : an introduction to the chimeric flap principle

Isao Koshima; Hidekazu Yamamoto; Masaru Hosoda; Takahiko Moriguchi; Yozo Orita; Hisao Nagayama

Chimeric composite flaps combined using microanastomoses consist of two or more flaps or tissues, each with an isolated pedicle and a single vascular source. Free combined chimeric flaps using the lateral circumflex femoral system were used to treat massive composite defects of the head and neck in 10 cases. A combined anterolateral thigh flap and vascularized iliac bone graft based on the lateral circumflex femoral system and the deep circumflex iliac system was the most commonly used combination. An anteromedial thigh flap and a paraumbilical perforator-based flap were also combined with this principal combination. The advantages of this chimeric flap over other osteocutaneous flaps are: (1) The flap is relatively thin and the pedicle vessels are up to 10 cm longer and are wider than those of other flaps for easier harvesting of the flap. (2) It is unnecessary to reposition the patient. (3) The vascular pedicle to the skin can be separated from that of the bone. (4) The donor site is not close to the receipient site. (5) The donor scar is in an unexposed area. (6) The skin territory of this flap is extremely wide. (7) A combined anterolateral and anteromedial thigh flap and vascularized iliac bone graft can be easily obtained as an extended combined osteocutaneous flap. (8) Other neighboring skin flaps, such as a groin flap, a paraumbilical perforator-based flap, or a medial thigh flap, can be combined with this chimeric flap because several major muscle branches to be anastomosed derive from the lateral circumflex femoral system.Chimeric composite flaps using the lateral circumflex femoral system are considered suitable for the repair of massive composite defects of the head and neck. (Plast. Reconstr. Surg. 92: 411, 1993.)


Annals of Plastic Surgery | 1996

Free medial thigh perforator-based flaps: new definition of the pedicle vessels and versatile application.

Isao Koshima; Masaru Hosoda; Kiichi Inagawa; Takahiko Moriguchi; Yozo Orita

The medial thigh flap is a perforator-based flap nourished with septocutaneous or muscle perforators originating from the femoral vessels. To date, 8 patients have been repaired with this flap and extended or connected flaps including this flap: 4 patients with lower leg defects and 4 patients with intraoral and neck defects. The advantages of this flap are (1) several pedicle perforators exist for this flap, which makes possible duplicated vascular anastomoses to establish reliable circulation of the transferred flap; (2) the flap can be extended or connected to other neighboring flaps in the anterior thigh, so that extensively wide defects can be closed in one stage; (3) the great saphenous vein can be simultaneously used as a vein graft or for venous drainage for the flap; (4) the anterior branch of the femoral nerve can be used for sensory potential; and (5) there is minimum morbidity of the donor defect and a large dominant vessel for the leg can be preserved. The suitable indications for this flap are defects after removal of skin cancer in the foot or lower leg and wide defects after resection of head and neck cancer, which can be reconstructed with the flap connected to neighboring skin flaps. The disadvantages of this flap are that it has a small, short vascular pedicle and the bulkiness of the flaps fatty tissue often requires thinning.


Journal of Medical Virology | 1998

Detection of varicella-zoster virus DNA in peripheral mononuclear cells from patients with Ramsay Hunt syndrome or zoster sine herpete.

Kihei Terada; Takahiro Niizuma; Shoji Kawano; Naoki Kataoka; Takeshi Akisada; Yozo Orita

On the basis of alterations in varicella‐zoster virus (VZV) antibody titers, it appears that Bells palsy in some patients could be associated with VZV reactivation, that is, zoster sine herpete. To obtain stronger evidence of this association, polymerase chain reaction (PCR) was used to detect VZV DNA in auricular lesions or peripheral blood mononuclear cells (PBMCs) from Bells palsy or Ramsay Hunt syndrome patients. VZV DNA was detected in the auricular lesions of Ramsay Hunt syndrome, in PBMCs from 2 Ramsay Hunt syndrome patients, and in 4 of 17 samples from 16 Bells palsy patients. Three of these four positive patients were thought to have zoster sine herpete because of hearing difficulty, vertigo, and pain. VZV IgM antibodies were positive in 1 of the 2 patients with Ramsay Hunt syndrome, and in 2 of the 17 samples from the Bells palsy patients. VZV IgG antibody titers during the acute phase were significantly higher in the patients positive for the PCR or VZV IgM antibody than in those negative for them. These findings provide evidence that Bells palsy in some patients could be associated with VZV reactivation. J. Med. Virol. 56:359–363, 1998.


European Journal of Radiology | 1995

Superselective cisplatin (CDDP)-carboplatin (CBDCA) combined infusion for head and neck cancers.

Shigeki Imai; Yasumasa Kajihara; Osamu Munemori; Tsuyoshi Kamei; Toshihiro Mori; Toru Handa; Ken Akisada; Yozo Orita

A group of 26 patients with carcinoma of the head and neck region was treated by superselective intra-arterial infusion of cisplatin (CDDP)-carboplatin (CBDCA). The tumor locations included the tongue (n = 4), oral base (n = 2), nasopharynx (n = 2), oropharynx (n = 8), hypopharynx (n = 4) and larynx (n = 4). Using the coaxial technique, a microcatheter was placed in the lingual, ascending pharyngeal, facial and superior thyroidal arteries according to the location of the tumor. Under imaging studies, CDDP (50 mg/m2)-CBDCA (300 mg/m2) was infused into the vessel, via injectors at the rate of 12.5 ml/min. One to five injections were given every 4 weeks. During and following the chemotherapy the patients received radiotherapy (n = 22), surgery (n = 4) or both (n = 3). Sixty-six sessions of intra-arterial chemotherapy were given with no major complications. Drug-related systemic side effects were mild. The overall response rate was 96% (complete response (CR) 50% and partial response (PR) 46%). Superselective CDDP-CBDCA combined infusion is feasible, relatively non-toxic, and important as multimodality therapy.


Acta Oto-laryngologica | 1998

Gap Junction Change in Supporting Cells of the Organ of Corti with Ryanodine and Caffeine

Yukihiro Sato; Toru Handa; Moto Matsumura; Yozo Orita

It has been demonstrated that the gap junctions of the supporting cells of the organ of Corti are controlled by H+ and Ca2+. Inside these cells there is a tubular structure. It is supposed that this network is endoplasmic reticulum. Calcium release from inside the cells, and the effect of calcium on the gap junctions of these cells, were investigated under whole cell clamping application of ryanodine and caffeine. Membrane capacitance and membrane resistance were calculated, with corrections for changes in whole cell parameters. Ryanodine-treated cells (1 microM-10 mM), caffeine-treated cells (5 mM 500 nM) and A23187-treated cells were uncoupled at their gap junctions. Therefore, Ca2+ plays a role in the uncoupling of the gap junctions in supporting cells of the organ of Corti from inside the cells.


Annals of Plastic Surgery | 1992

Extended latissimus dorsi musculocutaneous flaps for extremely wide cervical skin defects involving the cervical esophagus.

Isao Koshima; Takahiko Moriguchi; Shugo Soeda; Hidekazu Yamamoto; Yozo Orita; Akira Hara

Two cases using island distally and anteriorly extended latissimus dorsi musculocutaneous flaps for one-stage reconstruction of pharyngoesophageal defects of the entire front of the neck are reported. The advantage of this flap is its extremely large skin territory, which provides a reliable vascular supply. This flap is suitable for extremely wide cervical defects where the recipient vessels are damaged after severe infection and irradiation.


Plastic and Reconstructive Surgery | 1997

a Full-thickness Chondrocutaneous Flap from the Auricular Concha for Repair of Tracheal Defects

Isao Koshima; Naoto Umeda; Takahiko Moriguchi; Toru Handa; Ken Akisada; Yozo Orita

&NA; A free full‐thickness chondrocutaneous flap from the auricular concha for the repair of large tracheal defects was transferred successfully. The flap is based on the superficial temporal vessels (reversed flow) and the posterior auricular vessels. The advantages of this flap for the repair of tracheal defects are (1) its dissection is easy, (2) thin components of the flap provide a wide postoperative airway, (3) the structure of the reconstructed trachea is made firm by the conchal cartilage with vascularization, (4) the highly vascularized cartilage results in less resorption than a free cartilage graft, (5) the donor site can be repaired easily and is concealed by the remnant auricle, and (6) a long arterial pedicle (reversed flow) can be obtained. The disadvantages are (1) there may be temporary postoperative congestion of the flap, (2) postoperative narrowing of the auriculocephalic sulcus may occur, and (3) a short venous pedicle often requires a vein graft. (Plast. Reconstr. Surg. 99: 1887, 1997.)


American Journal of Otolaryngology | 1988

An inner ear anomaly in golden hamsters

Hiroshi Fujita; Yozo Orita

A new mutation of the inner ear was discovered in golden hamsters raised in our laboratories. Although scanning electron microscopy showed a normal arrangement of individual stereocilia on the first row of outer hair cells, the entire bundle of stereocilia were irregular in orientation and scattered in several directions. Seventy per cent to 85% of the stereociliary bundles were found to be abnormal throughout the cochlea, with no apparent difference between the right and left sides. Transmission electron microscopy showed that the cuticles of the first row of the outer hair cells were dislocated, but no dislocation due to this mutation was apparent in the lower portions. This mutation of the inner ear was already present in the basal turn four days after birth. The kinocilium was located outside of the stereocilia in the first row of outer hair cells, but sensory hairs were scattered in every direction, as in the adult animals. A comparison of auditory brainstem response tests revealed no difference between the abnormal and normal hamsters.


International Journal of Clinical Oncology | 1998

Arterial embolization for control of bleeding in advanced head and neck malignancy

Shigeki Imai; Yasumasa Kajihara; Tsuyoshi Kamei; Kuwako Komaki; Tsutomu Tamada; Hiroshi Shirai; Masayuki Gyoten; Toru Handa; Takeshi Akisada; Yozo Orita

BackgroundThis study was undertaken to assess the efficacy and suitability of an arterial embolization technique for the control of bleeding in advanced head and neck malignancies.MethodsEmbolization was performed on 6 patients with advanced head and neck malignancy using various embolic materials for the control of bleeding. The primary tumors were located in the nasopharynx, hypopharynx (n=2), oral base, face, and external auditory canal. All of these patients had severe anemia and 5 had massive regional hemorrhages.All bleeding was well controlled by the arterial embolization; 2 patients were cured of hypovolemic shock. None of the patients died as a direct result of tumor bleeding, and there were no massive rebleeding cases in our series.ConclusionArterial embolization offers an effective, safe, and fast method for controlling bleeding from advanced head and neck malignancies. A good working relationship between the surgeon and the interventional radiologist provides the greatest chance for sucess in such cases.


Practica oto-rhino-laryngologica | 1998

A Case of Cat Scratch Disease

Masaya Oku; Takeshi Akisada; Tsuyoshi Yoshihiro; Kanae Okumoto; Takuji Takemoto; Yozo Orita

We present a case of cat scratch disease. The patient was an 18 year-old female with no history of cat scratches, although she kept five cats. She noticed lymph node swelling in the right subparotid region. A malignant lymphoma was suspected, so the mass was surgically removed. Histopathologically, focal granulomatous lesions with necrosis were found in the subparotid lymph node. The necrosis was surrounded by a layer of epithelioid cells. The diagnosis of cat scratch disease was made on the basis of the clinical and histopathological features.

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Toru Handa

Kawasaki Medical School

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