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Biomedical subjects

Y Shiratsuchi

Publications and source records attributed to Y Shiratsuchi.

17 recordsLinked to original sources
PubMed2005

Healing of fractures in osteoporotic rat mandible shown by the expression of bone morphogenetic protein-2 and tumour necrosis factor-alpha.

We studied the healing process of mandibular closed fractures in osteoporotic rats using specific antibodies to bone morphogenetic protein-2 (BMP-2) and tumour necrosis factor-alpha (TNF-alpha). We confirmed the osteoporosis in rats after oophorectomy by micro-CT, and then caused unilateral closed fractures in the mandible and monitored the healing process after 7, 14, 21, and 28 days. Data were compared simultaneously with those from a group of rats that had a sham operation. During healing of the fracture in the osteoporotic group there was a prolonged phase of endochondral ossification, with an increased number of osteoclasts (p<0.01). Expressions of BMP-2 and TNFalpha were more pronounced in the osteoporotic group and there was an increase in the number of osteoblasts and TNFalpha(+) cells compared with the normal control (p<0.01). BMP-2 was related to the differentiation of osteoblasts and the higher values of TNFalpha were correlated with the up-regulation of osteoclasts during the prolonged phase of bone turnover. We conclude that the healing of fractures in osteoporotic bone is delayed about a week compared with controls. In the healing of fractures in osteoporotic bone, there were more osteoblasts and osteoclasts but there was a predominance of osteoclasts probably induced by TNFalpha. The prolonged phase of bone turnover with osteoclast predominance in the osteoporotic group is suggestive of the cause of delay in the healing of the fracture.

Animals↗
PubMed2002

Lymphoepithelial lesion of the parotid gland.

We describe a case of lymphoepithelial lesion of the parotid gland, also known as salivary lymphoepithelial lesion. Lymphoepithelial lesions are usually seen in conjunction with autoimmune disease of the salivary glands and these lesions do not always remain benign. Our case consisted of two masses that had different imaging features. Moreover, we could investigate the changes of the size and internal architecture on imaging due to the postponement of surgical intervention on the masses. At review 6 months later, the size of the masses had increased. The aims of this paper were to: (1) investigate the contribution of gray-scale sonography, power Doppler sonography, magnetic resonance imaging, and computed tomography to the diagnosis; and (2) consider the appropriate imaging modality to follow-up this case to monitor for recurrence or malignant transformation.

Diagnosis, Differential↗
PubMed2001

Immunohistochemical evaluation of PCNA and Ki-67 in ameloblastoma.

Thirty-two ameloblastoma tissues were immunohistochemically studied using monoclonal anti-proliferating cell nuclear antigen (PCNA) and anti-Ki-67 antibodies. Positive cells were evaluated and analyzed in relation to the WHO classification, cytological pattern of the outer layer cell, clinical appearance, tumor location, radiographic appearance and patient's age. In regard to the cytological pattern of the outer layer cells, the basal cell type had significantly higher PCNA and Ki-67 (P<0.05) labeling indices than the cuboidal cell type. The solid type had significantly higher PCNA and Ki-67 (P<0.05) labeling indices than the cystic and the mixed type. The labeling index of the younger patient was found to be the lowest, the middle age was in the middle and the older patient was the highest. These results indicated that the proliferating activities of ameloblastomas are quite variable, and the evaluations of Ki-67 and PCNA seem to be good indicators to assess the proliferating activity of each type of ameloblastomas.

Adolescent↗
PubMed2001

Two relatively distinct patterns of ameloblastoma: an anti-apoptotic proliferating site in the outer layer (periphery) and a pro-apoptotic differentiating site in the inner layer (centre).

AIMS: This study was performed to determine the apoptotic behaviour of ameloblastomas by analysing the role of bcl-2 family proteins in ameloblastomas and the location of terminally apoptotic cells in the ameloblastoma epithelial tissues. METHODS AND RESULTS: For immunohistochemistry, tissue sections of 32 patients were treated with an antigen-retrieval METHOD: Primary antibodies against the apoptosis-related proteins, bcl-2, bcl-X, bax, and bak were applied. Besides immunohistochemistry, Western blotting and TUNEL were also performed. Most of the outer layer cells were predominantly stained by the bcl-2 antibody, while most of the inner layer cells were stained by antibodies against the apoptosis-modulating proteins, bax and bak. Among the bcl-2 family, bcl-2 was the most ubiquitously expressed protein in ameloblastomas, while bcl-X was expressed in the greatest concentrations. The major bcl-X protein was bcl-XL. Some of the inner layer cells entered the terminal apoptotic stage, which were revealed by TUNEL. The acanthomatous areas over-expressed the apoptosis-modulating proteins, especially bak. CONCLUSIONS: Ameloblastoma has much more apoptosis-inhibiting protein than the apoptosis-modulating protein. Ameloblastoma has two relatively distinct patterns, an anti-apoptotic proliferating site in the outer layer (periphery) and a pro-apoptotic differentiating site in the inner layer (centre). The acanthomatous area, which was stained strongly by bak antibody and contained numerous terminally apoptotic cells, was considered as the differentiated area.

Adolescent↗
PubMed2001

[Significance of nucleic acid extraction for the performance of COBAS AMPLICOR Mycobacterium-PCR assay].

On an AMPLICOR-PCR assay for the diagnosis of mycobacterial infections, it has been found that approximately 10% of the routinely performed assays appear as indefinable cases with internal control (IC)-negative, which is caused by contaminant PCR-inhibitory substances in the extracted nucleic sample. To decrease the number of indefinable cases, we studied the IC performance of four nucleic acid extraction methods in one manual method(A) and three commercial kits(B, C and D). Thirty samples from 10 kinds of specimens without mycobacterial infections were subjected to the four nucleic extraction methods and the nucleic extracts were compared on PCR-inhibitory. The frequency of IC-negative samples was different among the four methods and the rates were 33.3%(n = 10) in A, 30.0%(n = 9) in B, 16.7%(n = 5) in C and 6.7%(n = 2) in D. In the PCR-inhibitory experiments using serially diluted IC-negative samples, the recovery of IC positivity was also different according to the method used. Although the IC-negative nucleic samples by D method easily became IC-positive at the 1/5 range of dilution, some of the IC-negative nucleic samples by A, B or C method were still IC-negative in the 1/10 range. These results indicate that the occurrence rate of indefinable cases with IC-negative is markedly different in the nucleic extraction method, suggesting that utilizing a suitable nucleic acid extraction method is important when using the diagnostic AMPLICOR-PCR assay.

DNA, Bacterial↗
PubMed1998

Long-term outcomes of nonsurgical treatment in nonreducing anteriorly displaced disk of the temporomandibular joint.

OBJECTIVES: The aim of this study was to evaluate long-term outcomes of nonsurgical treatment in patients with persistent anterior disk displacement without reduction of the temporomandibular joint. STUDY DESIGN: Thirty-five patients were treated with occlusal splints, and 12 patients underwent additional occlusal treatments after splint treatment. These patients were evaluated clinically and radiographically. At least 2 years after the treatment, the 34 patients' symptoms were assessed with the use of a questionnaire. RESULTS: The mean maximal interincisal distance (MID) was 27.6 mm before treatment and 44.4 mm at the end of treatment (p < 0.001). Before the treatment, all 35 patients had complained of pain, and mild pain persisted in 9 patients at the end of treatment. Flattening of the condylar head and of the articular eminence increased in prevalence from 12.1% and 9.1%, respectively, before treatment to 54.5% and 51.5%, respectively, at the time of follow-up observation. At the time of the survey, the mean self-reported MID was 46.8 mm (p < 0.01). CONCLUSIONS: After the nonsurgical treatment, the clinical signs and symptoms improved significantly, although the prevalence of osteoarthrotic findings increased.

Adolescent↗
PubMed1993

Stafne's bone cavity. Classification based on outline and content determined by computed tomography.

Fifteen cases (16 concavities) of the so-called "Stafne's bone cavity" were investigated with the use of computed tomography. The sizes, bony outlines, and contents were analyzed on axial images. In all cases, computed tomography clearly demonstrated the concavities on the lingual surface of the mandible. There were no empty concavities. The bony outlines and contents were divided into three types. The concavities with a portion of submandibular gland as a content were larger than those with other contents. Four of six concavities not extending to the buccal cortical plate were filled solely with fat tissue, whereas all concavities with expansion of the buccal cortical plate contained submandibular gland.

Adipose Tissue↗
PubMed1993

Mandibular reconstruction using hydroxylapatite granules, autogenous bone, and a cervical island skin flap.

Ten patients with gingival carcinoma who were treated by marginal mandibulectomy were reconstructed using hydroxylapatite granules, autogenous bone chips, and a cervical island skin flap. The cervical flap was used to produce a cover and partition, designed to prevent the displacement of the mixture of hydroxylapatite and bone. Reconstruction was successfully achieved in all patients. Loss of height of the reconstructed mandible over an average 18-month follow-up ranged from 8% to 22%. One patient has worn a full denture and five patients wear partial dentures.

Aged↗
PubMed1991

Evaluation of masticatory function following orthognathic surgical correction of mandibular prognathism.

Masticatory function was examined in 17 patients with mandibular prognathism before and after bilateral sagittal splitting osteotomy of the mandibular rami. Masticatory efficiency was measured by means of a spectrophotometer, using adenosine triphosphate (ATP) granules, the biting force and occlusal contact area. Masticatory functions showed a tendency to gradual improvement postoperatively. Concerning masticatory efficiency, mean values of absorbance of ATP granules in patients with mandibular prognathism were inferior to those of subjects who possess a normal occlusion, even 12 months after operation.

Bite Force↗
PubMed1990

Multiple endocrine neoplasia type 3: three cases with mucosal neuromata.

Three female patients (ages 10, 18 & 25 years) with multiple endocrine neoplasia type 3 are reported. They had all characteristic facial appearances, with mucosal neuromata, rubbery swollen lips, tubercles on the tongue and eversion of the eye lids. Clinical signs and symptoms appeared to be progressive with increase in age, suggesting the importance of the correct diagnosis and early evaluation of endocrine function leading to a better prognosis for the patient.

Adolescent↗
PubMed1988

Familial occurrence of oral cancer: report of cases.

Four cases of familial occurrence of oral cancer are described and the postulated causes and predisposing factors of oral cancer are reviewed. None of these factors could satisfactorily explain the unusual familial occurrence observed in the cases presented.

Adult↗
PubMed1988

Mandibular ameloblastoma associated with salivary gland tumor.

2 cases of mandibular ameloblastoma associated with salivary gland tumor are presented. Case no. 1, a 32-year-old male was diagnosed as mandibular ameloblastoma and acinic cell tumor of the submandibular gland, both of which were found on the left side. Case no. 2, a 62-year-old male was diagnosed as recurrent ameloblastoma of the mandible and adenolymphoma adjacent to a lower pole of the parotid gland.

Adenolymphoma↗
PubMed1988

[An easily and immediately releasable intermaxillary fixation appliance for use after the correction of surgical orthognathic cases of jaw deformity or fracture].

In oral surgery, intermaxillary fixation is routinely applied after surgery in cases of surgical orthognathic correction of jaw deformity or fractures. Intermaxillary fixation requires two conflicting factors: Stiff fixation and quick release in an emergency, as in nausea and vomiting. Conventional methods of intermaxillary fixation require multiple stiff ligation after an operation, but in an emergency these ligations can not be cut quickly to free the airway. We have developed a new fixation method placing a third wire (locking bow) above the upper splint or below the lower splint. The locking bow is hooked onto the splint on the unoperated side and firmly ligated to the splint on the jaw being operated upon. The ligatures can be quickly and easily released by pulling out the locking bow. This can be done by the patient himself or another person. This article describes the principles and clinical application of the method. We have found it to be useful in clinical practice.

Equipment Design↗
PubMed1987

Hemorrhagic cyst of the mandible associated with a retained root apex of the lower third molar.

An unusual case of hemorrhagic cyst of the mandible, associated with a retained root of the lower right third molar, is reported. The cyst was revealed by routine radiologic examination as part of treatment of the lower right second molar. Radiologically, a faintly outlined cavity with radiopaque mass was found in the third molar region. A final diagnosis of this condition was made after surgical intervention and histologic examination. A nonepithelial lining cavity was found, and the radiopaque mass was identified as a root apex.

Adult↗
PubMed1986

Posterior lingual mandibular bone depression.

An unusual case of posterior lingual mandibular bone depression in a 39-year-old Japanese man is reported. The bilocular type of this condition was composed of 2 large ovoid radiolucent areas which were adjacent to each other. The diagnosis of this condition was made by sialography and tomography. The present case was compared with other unusual cases reported in the Japanese literature.

Adult↗