Yoshiyuki Mori

Novel metal allergy patch test using metal nanoballs

BackgroundPatch tests are often used in the clinical diagnosis of metal allergies. In currently available patch tests, high concentrations of metal salt solutions are used. However, diagnosis accuracy can be influenced not only by acute skin reactions to high concentrations of metal salt, but also by skin reactions to other components present in the patch or to pH changes. In this study, we developed Ni nanoparticles (termed “nanoballs”) for use in patch-test solutions.FindingsHighly soluble, spherical Ni nanoballs were prepared using plasma electrolysis. The Ni released from the nanoballs permeated through a dialysis membrane, and the nanoball-containing solution’s pH was maintained constant. Ni ions were released slowly at low concentrations in a time-dependent manner, which contrasted the rapid release observed in the case of a commercial patch test. Consequently, in the new test system, reactions caused by high concentrations of metal salts were avoided.ConclusionsBy exploiting the high specific surface area of Ni nanoballs, we obtained an effective dissolution of Ni ions that triggered Ni allergy in the absence of direct contact between the nanoballs and mouse skin. This novel patch system can be applied to other metals and alloys for diagnosing various types of metal-induced contact dermatitis.

Detection of trace metallic elements in oral lichenoid contact lesions using SR-XRF, PIXE, and XAFS

Oral lichen planus (OLP) and oral lichenoid contact lesions (OLCL) are chronic inflammatory mucocutaneous reactions with a risk of malignant transformation that alter the epithelium. OLP and OLCL have similar clinical and histopathological features and it is difficult to distinguish one from the other. Metallic restorations are suspected to generate OLCLs. Trace metal analysis of OLCL specimens may facilitate the discrimination of symptoms and identification of causative metallic restorations. The purpose of this study was to assess OLCL tissue samples for the prevalence of metallic elements derived from dental restorations, and to discriminate OLCL from OLP by using synchrotron radiation-excited X-ray fluorescence analysis (SR-XRF), particle-induced X-ray emission (PIXE), and X-ray absorption fine structure (XAFS). Typical elements of dental materials were detected in the OLCL, whereas no obvious element accumulation was detected in OLP and negative control specimens. The origin of the detected metallic elements was presumed to be dental alloys through erosion. Therefore, our findings support the feasibility of providing supporting information to distinguish OLCL from OLP by using elemental analysis.

High-risk oral leukoplakia is associated with aberrant promoter methylation of multiple genes

BackgroundEarly detection of oral squamous cell carcinomas (OSCCs) is urgently needed to improve the prognosis and quality of life (QOL) of patients. Oral leukoplakias (OLs), known as the most common premalignant lesions in the oral cavity, often precede OSCCs. Especially, OLs with dysplasia are known to have a high risk of malignant transformation. Here, we searched for the promoter methylation characteristic of high-risk OLs.MethodsTo identify methylation-silenced genes, a combined analysis of methylated DNA immunoprecipitation (MeDIP)u2009−u2009CpG island (CGI) microarray analysis and expression microarray analysis after treatment with a demethylating agent was performed in two OSCC cell lines (Ca9–22 and HSC-2). The methylation statuses of each gene were examined by methylation-specific PCR.ResultsA total of 52 genes were identified as candidates for methylation-silenced genes in Ca9-22 or HSC-2. The promoter regions of 13 genes among the 15 genes randomly selected for further analysis were confirmed to be methylated in one or more of five cell lines. In OSCC tissues (nu2009=u200926), 8 of the 13 genes, TSPYL5, EGFLAM, CLDN11, NKX2-3, RBP4, CMTM3, TRPC4, and MAP6, were methylated. In OL tissues (nu2009=u200924), seven of the eight genes, except for EGFLAM, were found to be methylated in their promoter regions. There were significantly greater numbers of methylated genes in OLs with dysplasia than in those without dysplasia (pu2009<u20090.0001).ConclusionsOLs at high risk for malignant transformation were associated with aberrant promoter methylation of multiple genes.

Anxiety and depression in patients after surgery for head and neck cancer in Japan

OBJECTIVEnThe present study sought to examine the impact of physical symptoms, facial disfigurement, adequacy of preoperative information, and social support on anxiety and depression in Japanese patients with head and neck cancer (HNC) who had undergone surgery.nnnMETHODnA cross-sectional study with 194 patients was conducted using a self-administered questionnaire. This instruments included the Hospital Anxiety and Depression Scale (HADS), the European Organization for Research and Treatment of Cancer (EORTC) Head and Neck cancer module (QLQ-H&N35), and a Social Support Scale developed by Okabayashi et al. (1997).nnnRESULTSnThe majority (56.7%) had surgery two or more years before completing the questionnaire. More than 25% of respondents showed anxiety or depression. Higher levels of perceived social support were associated with lower rates of anxiety and depression (p < 0.01). Sensory problems were associated with anxiety, and reduced sexuality was associated with depression (p < 0.01). Perceived disfigurement and adequacy of preoperative information were not associated with anxiety or depression.nnnSIGNIFICANCE OF RESULTSnSurvivors of HNC experience anxiety and depression for an extended period of time. Social support may alleviate the severity of these disorders. More research is needed to confirm the impact of facial disfigurement and that of the preoperative information provided by surgeons on psychological distress in HNC patients.

Copper accumulation in the sequestrum of medication-related osteonecrosis of the jaw

Bisphosphonates (BPs) have been widely, efficiently, and safely used for the treatment of various bone-related diseases such as osteoporosis. However, concerns about jaw osteonecrosis associated with oral treatment (medication-related osteonecrosis of the jaw [MRONJ]) have been increasing. Although many risk factors for MRONJ have been elucidated, its precise etiology and methods of prevention remain unknown. In this study, we have applied various elemental analysis methods for MRONJ specimens (e.g., X-ray fluorescence with synchrotron radiation [SR-XRF], particle-induced X-ray emission [PIXE], X-ray absorption fine structure [XAFS]) in order to reveal the accumulation and chemical state of trace bone minerals. In four MRONJ sequestra, the characteristic localization of copper (Cu) was observed by SR-XRF. Using micro-PIXE analysis, Cu looked to be localized near the edge of the trabecular bone. The chemical state of the accumulated Cu was estimated using XAFS and the possibility of a Cu–BP complex formation was assumed. Thus, in this study we argue for the feasibility of the trace element analysis to evaluate the potential pathophysiological mechanism of MRONJ.

Six1 is required for mouse dental follicle cell and human periodontal ligament-derived cell proliferation

The periodontal ligament (PDL) is a connective tissue that attaches the tooth cementum to the alveolar bone and is derived from dental follicle cells (DFCs). The DFCs form fibroblasts, osteoblasts, cementoblasts, and PDL stem cells (PDLSCs). We previously reported homeobox transcription factor Six1 expression in mouse DFCs. However, the role of Six1 in periodontal tissue development is largely unknown. In this study, we analyzed SIX1 expression in mouse periodontal tissue cells during postnatal development and adulthood. We also addressed the role of SIX1 in mouse periodontium development and in human cultured PDL‐derived cells (PDLCs). In mouse development, SIX1 production was abundant in DFCs and PDL cells by 2 weeks, but it was greatly diminished in the PDL at 4 weeks and in adults. Although the SIX1‐positive cell distribution was sparse in the adult PDL, SIX1‐positive cells were observed with low expression levels. We used 5‐ethynyl‐2′‐deoxyuridine (EdU) for cell labeling to reveal numerous EdU/SIX1‐double positive cells at 2 weeks; however, a few EdU‐positive cells remained at 4 weeks. The proportion of DFCs that incorporated EdU was significantly lower in Six1‐deficient mice compared with wild‐type mice at E18.5. In human PDLCs, SIX1 was intensely expressed, and SIX1‐knockdown using siRNA reduced proliferating PDLCs. Our results suggest that SIX1 is a key proliferation regulator in mouse DFCs and human PDLCs, which provides novel insight into Six family gene function in mammals.

A method to visualize transdermal nickel permeation in mouse skin using a nickel allergy patch

Metal patch test is often used in clinical settings when metal-induced contact dermatitis is suspected. However, the transdermal permeation behavior of metal ions from the patch test remains unclear. Current patch tests using high concentrations of metal salt solutions have some side effects, e.g. acute skin reactions to high concentrations of metal salt. To resolve these, estimating metal ion transdermal permeation is wished. In this study, synchrotron radiation X-ray fluorescence (SR-XRF) and micro-focused particle-induced X-ray emission (micro-PIXE) were used to visualize the time-dependent Ni permeation in mouse skin. The cross-sectional diffusion of Ni was visualized in a time-dependent manner. Our results indicate that maximum Ni permeation occurs after 24 h of patch treatment, and the permeated Ni content was high in the epidermis and spread into the dermis beyond the basal layer. This method may be useful to determine the appropriate solution concentration and duration of administration for the patch test.

Multiple primary malignant neoplasms of the glottis, renal pelvis, urinary bladder, oral floor, prostate, and esophagus in a Japanese male patient: a case report.

Owing to recent advances in diagnostic and surgical techniques for cancer, a patient diagnosed with two or more neoplasms is not rare. We report on the case of a 58-year-old male with multiple primary malignant neoplasms, who suffered from three histological types of malignant neoplasm in six organs, namely the glottis, renal pelvis, urinary bladder, oral floor, prostate, and esophagus in chronological order. The first neoplasm was a squamous cell carcinoma of the glottis diagnosed in 2006. The second and third neoplasms were urothelial carcinomas of the right renal pelvis and urinary bladder, respectively, diagnosed in 2008. The remaining three neoplasms were diagnosed in 2010, namely a squamous cell carcinoma of the oral floor, an adenocarcinoma of the prostate, and a squamous cell carcinoma of the esophagus. The glottic cancer and esophageal cancer were treated by external radiation therapy. The malignant neoplasms of the oral floor and those which originated in the urinary tract were surgically resected. All neoplasms except the malignant neoplasm of the oral floor were well controlled. The patient died of cervical lymph node metastasis from the squamous cell carcinoma of the oral floor in January 2011. As far as we know, the present report is the first one on this combination of primary malignant neoplasms.

Expression of protein arginine methyltransferase-5 in oral squamous cell carcinoma and its significance in epithelial-to-mesenchymal transition: PRMT5 in oral SCC

Protein arginine methyltransferases (PRMT) 5, a member of type II arginine methyltransferases, catalyzes the symmetrical dimethylation of arginine residues on histone and non‐histone substrates. Although the overexpression of PRMT5 has been reported in various cancers, its role in oral squamous cell carcinoma (OSCC) has not been elucidated. In the present study, we immunohistochemically examined the expression of PRMT5 in surgically resected oral epithelial dysplasia (OED, nu2009=u20098), oral intraepithelial neoplasia (OIN)/carcinoma in situ (CIS) (nu2009=u200911) and OSCC (nu2009=u200952) with or without contiguous OED lesions. In the normal epithelium, PRMT5 was weakly expressed in the cytoplasm of basal layer cells. In OED, OIN/CIS, and OSCC, its expression consistently and uniformly increased in the cytoplasm of dysplastic and cancer cells. Moreover, nuclear and cytoplasmic localization was detected in the invasive front of cancer cells, particularly in cases showing poor differentiation or aggressive invasion patterns. The concomitant nuclear and cytoplasmic expression of PRMT5 correlated with the loss of E‐cadherin and cytokeratin 17, and the upregulation of vimentin, features that are both indicative of epithelial‐to‐mesenchymal transition. PRMT5 may play a role from early oncogenesis through to the progression of OSCC, particularly in the aggressive mode of stromal invasion.

Evaluation of postoperative changes in vascularized iliac bone grafts used for mandibular reconstruction

Vascularized iliac bone grafts are used for mandibular reconstruction, but the factors affecting graft maintenance are unknown. This study explored the postsurgical changes in vascularized iliac bone grafts in patients who had undergone mandibular reconstruction after segmental resection. The study involved 24 patients (16 men and eight women) with oral tumours or osteoradionecrosis. Thirteen patients required bare bone grafting (BBG) and 11 patients required reconstruction with soft tissue coverage (six with a skin paddle and five with direct closure). The bone graft maintenance rate (with regard to the height of the centre of the graft) was calculated immediately after surgery and at 3, 6, 12, 24, and 36months after surgery. The maintenance rate was significantly lower in the BBG group than in the soft tissue coverage group at 3, 6, 12, 24, and 36months, and in those who were fitted with dentures compared to those who were not at 6, 12, 24, and 36months. Local infection also influenced the maintenance rate, but not significantly so. These findings indicate that the reconstruction technique and denture use can affect the bone graft maintenance rate after mandibular reconstruction with vascularized iliac bone grafts.