Yoshio Ohyama - Academia.edu (original) (raw)

Papers by Yoshio Ohyama

Scientific Reports, 2022

Amelogenesis Imperfecta (AI) represents a group of hereditary conditions that manifest tooth enam... more Amelogenesis Imperfecta (AI) represents a group of hereditary conditions that manifest tooth enamel defects. Several causative mutations in the WDR72 gene have been identified and patients with WDR72 mutations have brown (or orange-brown) discolored enamel, rough enamel surface, early loss of enamel after tooth eruption, and severe attrition. Although the molecular function of WDR72 is not yet fully understood, a recent study suggested that WDR72 could be a facilitator of endocytic vesicle trafficking, which appears inconsistent with the previously reported cytoplasmic localization of WDR72. Therefore, the aims of our study were to investigate the tissues and cell lines in which WDR72 was expressed and to further determine the sub-cellular localization of WDR72. The expression of Wdr72 gene was investigated in mouse tissues and cell lines. Endogenous WDR72 protein was detected in the membranous fraction of ameloblast cell lines in addition to the cytosolic fraction. Sub-cellular loc...

Journal of medical and dental sciences, 2009

To determine whether staining with iodine solution provides an efficient criterion for determinin... more To determine whether staining with iodine solution provides an efficient criterion for determining the area of resection for the lesions surrounding squamous cell carcinoma (SCC) and leukoplakia of the tongue, we determined the optimum density of iodine solution and staining procedure and analyzed the color of lightly stained lesions (LSLs) in relation to the histopathologic findings. Sixty-five patients with SCC or leukoplakia of the tongue were divided into two groups: lesions stained with 3% Lugol solution and restained with either 5% Lugol solution (n=38) or 10% iodine glycerin (n=27). Among the lesions stained with 5% Lugol solution, significant differences were found in all color values. Color difference values (DeltaE*ab) using 3% and 5% Lugol solutions were significantly different between epithelial hyperplasia/mild epithelial dysplasia and moderate to severe dysplasia (P < 0.05). According to the evaluations of five clinicians in 46 LSLs, a distinctive boundary was most ...

Indian Journal of Otolaryngology and Head & Neck Surgery, 2021

Background Maxillary gingival squamous cell carcinoma (MGSCC) occurs rather infrequently, compare... more Background Maxillary gingival squamous cell carcinoma (MGSCC) occurs rather infrequently, compared to tongue and mandibular gingival carcinomas, among the cancers of the oral cavity. Therefore, signi cant numbers of MGSCC cases have not been statistically analysed. The aim of this study is to clarify the prognostic factors for MGSCC. Methods We performed the statistical analysis of 90 MGSCC cases primarily treated in our department from 1999 to 2014. Conclusions The patients (male: 36, female: 54) were aged between 38 and 93 years, and the mean age was 68.7 years. The number of patients in each tumour stage according to the TNM classi cation was as follows: T1: 15 cases, T2: 32 cases, T3: 13 cases, and T4: 30 cases. Forty-two patients were treated only by surgery, 5 only by radiotherapy, 3 by preoperative radiotherapy and surgery, and 40 patients were treated

Scientific Reports, 2020

It is widely accepted that FAM20C functions as a Golgi casein kinase and has large numbers of kin... more It is widely accepted that FAM20C functions as a Golgi casein kinase and has large numbers of kinase substrates within the secretory pathway. It has been previously reported that FAM20C is required for maintenance of healthy periodontal tissues. However, there has been no report that any extracellular matrix molecules expressed in periodontal tissues are indeed substrates of FAM20C. In this study, we sought to identify the binding partner(s) of FAM20C. FAM20C wild-type (WT) and its kinase inactive form D478A proteins were generated. These proteins were electrophoresed and the Coomassie Brilliant Blue (CBB)-positive bands were analyzed to identify FAM20C-binding protein(s) by Mass Spectrometry (MS) analysis. Periostin was found by the analysis and the binding between FAM20C and Periostin was investigated in cell cultures and in vitro. We further determined the binding region(s) within Periostin responsible for FAM20C-binding. Immunolocalization of FAM20C and Periostin was examined us...

Japanese Journal of Oral and Maxillofacial Surgery, 2018

Dentistry Journal, 2019

Dentigerous cysts are one of the most prevalent types of odontogenic cysts and are associated wit... more Dentigerous cysts are one of the most prevalent types of odontogenic cysts and are associated with the crown of an unerupted tooth, especially of the mandibular third molar. In this study, the characteristics of a dentigerous cyst developed around a mandibular third molar on panoramic radiographs were investigated. The panoramic images of 257 consecutive dentigerous cyst cases associated with a mandibular third molar were analyzed. The mean age of the patients was 45.9 ± 13.3 years. The size of the cyst did not significantly correlate to the age of the patient. The unilocular type (89.1%) and the crown side type (68.5%) were significant. The associated mandibular third molars had a high frequency of class III (64.6%) and position B (48.3%) in Pell and Gregory classification and of horizontal position (36.3%) in angulation. Dentigerous cysts were thought to originate and grow commonly around deeply impacted third molars. The associated third molar with dentigerous cyst tends to have ...

Calcified Tissue International, 2018

Journal of Japanese Society of Oral Oncology, 2017

Bilateral chylothorax is a rare complication of radical neck dissection. We experienced a case of... more Bilateral chylothorax is a rare complication of radical neck dissection. We experienced a case of bilateral chylothorax after neck dissection on the left side. A 54-year-old man with pain in the mandibular gingiva was referred to our hospital from a dental clinic on 28 th January 200X, and was diagnosed with squamous cell carcinoma of the left oral floor. Left radical neck dissection, right supraomohyoid neck dissection, marginal dissection of the left mandible, tumor resection of the left tongue and left oral floor, rectus abdominal free flap reconstruction, and tracheotomy were performed after preoperative chemoradiotherapy. On day 3 postoperatively, his oxygen saturation was remarkably decreased. Chest X-ray revealed bilateral pleural effusion. Pulmonary specialists were consulted and thoracic cavity drainage of the left side was performed. Biochemical analysis of the milky white effusion indicated bilateral chylothorax. On day 6 postoperatively, pleural effusion of the right thoracic cavity was increased, therefore a right thoracic drainage tube was inserted. A central venous catheter had been installed and total parenteral nutrition was initiated. Drainage from both sides of the chest decreased over the following week. As the volume of drainage fluid did not increase, the thoracic drainage tubes were removed 21 days after the operation. On day 22 postoperatively, medium-chain triglyceride diet was started. Over the five-year follow-up, the patient remains free from chylothorax.

Case Reports in Dentistry

Endoscopic sinus surgery is commonly performed to treat odontogenic maxillary sinusitis. However,... more Endoscopic sinus surgery is commonly performed to treat odontogenic maxillary sinusitis. However, recurrence and natural ostium reclosure often occur due to the inadequate patency of the excretory route. Furthermore, classical maxillary sinus radical surgery is still performed for odontogenic maxillary sinusitis even though it can cause postoperative maxillary sinus deformation, loss of function, and a postoperative maxillary cyst. A management that addresses these issues has not yet been identified. This study reported a conservative maxillary sinus management, wherein a nasoantral window is prepared and the thickened maxillary sinus mucosa is preserved, using the Caldwell–Luc approach. This study presents a case of severe odontogenic maxillary sinusitis that spread to the frontal sinus. This novel management facilitated complete recovery from severe odontogenic maxillary sinusitis in this case.

Journal of Japan Society for Oral Tumors, 2014

Japanese Journal of Oral & Maxillofacial Surgery, 2008

Sixteen cases of accidental insertion of foreign bodies into the maxillary sinus are reviewed. Th... more Sixteen cases of accidental insertion of foreign bodies into the maxillary sinus are reviewed. The patients were referred to our clinic between May 1994 and April 2004. There were many kinds of foreign bodies, such as tooth roots (50%), implants (13%), root canal filling material (6%), a reamer for dental treatment (6%), an interdental brush (6 %), and a fractured elevator (6%). These foreign bodies were removed in 11 of the 16 patients. The other 5 patients were followed up without surgical tratment because they had no symptoms or symptoms improved with drug therapy.

Background The prognosis of advanced oral cancer remains dismal. While multimodal therapy is bene... more Background The prognosis of advanced oral cancer remains dismal. While multimodal therapy is beneficial, maintaining the quality of life of long-term survivors is important. Therefore, risk-adapted treatment regimens need to be designed. We herein investigated whether pathological responses in oral cancer patients treated with preoperative chemoradiotherapy predict locoregional recurrence. Methods We retrospectively reviewed the data of 51 oral cancer patients who received preoperative radiotherapy and concurrent pepleomycin, followed by curative surgery at our institution between January 2009 and June 2018. Each patient received preoperative external beam irradiation to the primary tumor and lymphatics (2 Gy per day for approximately 3 weeks) concurrent with pepleomycin (2.5 mg/day). Surgery was performed approximately 3–4 weeks after the completion of preoperative chemoradiotherapy. Pathological responses were defined based on the grading system of Oboshi and Shimosato. Results Ei...

BMC Cancer, 2020

Journal of Japanese Society of Oral Oncology, 2016

Purpose : We performed a clinical study to evaluate the N classification. Materials and methods :... more Purpose : We performed a clinical study to evaluate the N classification. Materials and methods : 281 cases of primary oral squamous cell carcinoma, which were surgically resected with neck dissection, were selected. Cases with pre-operative radiotherapy or that recurred after the surgery, were excluded. Clinical examination and images such as US, CT, MRI, and PET/CT were used to diagnose metastasis of neck lymph nodes. We studied the concordance rate of the clinical classification (cN) , which expresses the existence and developed area of neck lymph node metastasis, and histopathological classification (pN). We also examined the accuracy of diagnostic tools. Results : The concordance rate of cN and pN classification was 60.5％. cN1 showed the lowest concordance (30.2％). The highest specificity of diagnostic accuracy was US, 86.3％, and the highest sensitivity was PET/CT, 74.7％. Conclusions : It is necessary to select diagnostic tools based on their characteristics for accurate diagnosis for N classification.

Biochemistry and biophysics reports, 2016

Bone and dentin are mineralized extracellular matrices produced by osteoblasts and odontoblasts, ... more Bone and dentin are mineralized extracellular matrices produced by osteoblasts and odontoblasts, respectively, and their major organic portion is type I collagen. Dentinogenesis Imperfecta (DGI) is one of the most common clinically- and genetically-based disturbances of dentin formation, causing irreversible dentin defects. Among several types of DGI, patients with DGI type II exhibit opalescent dentin with partial or complete pulp obliteration. It has been previously reported that the non-sense mutation (c.133C>T) in Dentin Sialophosphoprotein (DSPP) was identified in DGI type II patients at glutamine residue 45, resulting in the premature stop codon (p.Q45X). DSPP is known to be synthesized as a single gene product and further processed at Gly(462)-Asp(463), resulting in the production of Dentin Sialoprotein (DSP) and Dentin Phosphoprotein (DPP). We hypothesized that the shorter form (Q45X) of N-terminal Dentin Sialoprotein (N-DSP) may cause over-production of type I collagen p...

Archives of Oral Biology, 2016

Objective-Our objectives were to determine the expression of EVC2 in craniofacial tissues and inv... more Objective-Our objectives were to determine the expression of EVC2 in craniofacial tissues and investigate the effect of Evc2 deficiency on craniofacial bones using Evc2 knockout (KO) mouse model. Design-Evc2 KO mice were generated by introducing a premature stop codon followed by the Internal Ribosomal Entry Site fused to β-galactosidase (LacZ). Samples from wild-type (WT), heterozygous (Het) and homozygous Evc2 KO mice were prepared. LacZ staining and *

PloS one, 2016

Recent studies have shown that Notch signaling is involved in many types of cancers, including or... more Recent studies have shown that Notch signaling is involved in many types of cancers, including oral squamous cell carcinomas (OSCCs). However, the role of Notch signaling in the tumor microenvironment is not yet fully understood. In this study, we investigated the roles of NOTCH3 signaling in cancer associated fibroblasts (CAFs) in OSCCs. Immunohistochemical study of 93 human tongue OSCC cases indicated that about one third of OSCCs showed NOTCH3 expression in CAFs, and that this expression significantly correlated with tumor-size. In vitro study showed that OSCC cell lines, especially HO1-N-1 cells stimulated NOTCH3 expression in normal human dermal fibroblasts (NHDFs) through direct cell-to-cell contact. Immunohistochemical and morphometric analysis using human OSCC samples demonstrated that NOTCH3 expression in CAFs significantly correlated with micro-vessel density in cancer stroma. In vitro angiogenesis assays involving co-culture of NHDFs with HO1-N-1 and human umbilical endot...

Anatomical record (Hoboken, N.J. : 2007), Aug 18, 2016

Ellis-van Creveld (EvC) syndrome is a genetic disorder with mutations in either EVC or EVC2 gene.... more Ellis-van Creveld (EvC) syndrome is a genetic disorder with mutations in either EVC or EVC2 gene. Previous case studies reported that EvC patients underwent orthodontic treatment, suggesting the presence of craniofacial bone phenotypes. To investigate whether a mutation in EVC2 gene causes a craniofacial bone phenotype, Evc2 knockout (KO) mice were generated and cephalometric analysis was performed. The heads of wild type (WT), heterozygous (Het) and homozygous Evc2 KO mice (1-, 3- and 6-week-old) were prepared and cephalometric analysis based on the selected reference points on lateral X-ray radiographs was performed. The linear and angular bone measurements were then calculated, compared between WT, Het and KO and statistically analyzed at each time point. Our data showed that length of craniofacial bones in KO was significantly lowered by ∼20% to that of WT and Het, the growth of certain bones, including nasal bone, palatal length and premaxilla was more affected in KO, and the r...

Scientific Reports, 2016

Mutations in the Family with sequence similarity (FAM) 20 gene family are associated with mineral... more Mutations in the Family with sequence similarity (FAM) 20 gene family are associated with mineralized tissue phenotypes in humans. Among these genes, FAM20A mutations are associated with Amelogenesis Imperfecta (AI) with gingival hyperplasia and nephrocalcinosis, while FAM20C mutations cause Raine syndrome, exhibiting bone and craniofacial/dental abnormalities. Although it has been demonstrated that Raine syndrome associated-FAM20C mutants prevented FAM20C kinase activity and secretion, overexpression of the catalytically inactive D478A FAM20C mutant was detected in both cell extracts and the media. This suggests that FAM20C secretion doesn't require its kinase activity, and that another molecule(s) may control the secretion. In this study, we found that extracellular FAM20C localization was increased when wild-type (WT), but not AI-forms of FAM20A was co-transfected. On the other hand, extracellular FAM20C was absent in the conditioned media of mouse embryonic fibroblasts (MEFs) derived from Fam20a knockout (KO) mouse, while it was detected in the media from WT MEFs. We also showed that cells with the conditioned media of Fam20a WT MEFs mineralized, but those with the conditioned media of KO MEFs failed to mineralize in vitro. Our data thus demonstrate that FAM20A controls FAM20C localization that may assist in the extracellular function of FAM20C in mineralized tissues.