Cytoplasmic localization of DGKζ exerts a protective effect against p53-mediated cytotoxicity.

The transcription factor p53 plays a crucial role in coordinating the cellular response to various stresses. Therefore, p53 protein levels and activity need to be kept under tight control. We report here that diacylglycerol kinase ζ (DGKζ) binds to p53 and modulates its function both in the cytoplasm and nucleus. DGKζ, a member of the DGK family that metabolizes a lipid second messenger diacylglycerol, localizes primarily to the nucleus in various cell types. Recently, reports have described that excitotoxic stress induces DGKζ nucleocytoplasmic translocation in hippocampal neurons. In the study reported here we found that cytoplasmic DGKζ attenuates p53-mediated cytotoxicity against doxorubicin-induced DNA damage by facilitating cytoplasmic anchoring and degradation of p53 through a ubiquitin-proteasome system. Concomitantly, decreased levels of nuclear DGKζ engender downregulation of p53 transcriptional activity. Consistent with these in vitro cellular experiments, DGKζ-deficient brain exhibits high levels of p53 protein after kainate-induced seizures and even under normal conditions. These findings provide novel insights into the regulation of p53 function and suggest that DGKζ serves as a sentinel to control p53 function both during normal homeostasis and in stress responses.

Supernumerary impacted teeth in a patient with SOX2 anophthalmia syndrome.

SOX2 anophthalmia syndrome characteristically presents as anophthalmia or microphthalmia, with various extraocular symptoms, such as hypogonadotropic hypogonadism, brain anomaly, and esophageal abnormalities. In this report, we describe a patient with SOX2 anophthalmia syndrome complicated with a dental anomaly, multiple supernumerary impacted teeth, and persistence of deciduous teeth. Multiple supernumerary teeth are usually not solitary symptoms, but indicate systemic syndrome such as cleidocranial dysplasia. In odontogenesis, many transcriptional factors, such as BMPs, FGFs, and Wnts, play significant roles and SOX2 is known to interact with some of them. The role of SOX2 in dental development remains unknown, however, multiple supernumerary teeth can be considered as extraocular symptoms of SOX2 anophthalmia syndrome, rather than the coincidence of two rare diseases.

A case of multiple osseous choristomas arising on the medial side of the lateral pterygoid muscle.

Osseous choristoma is a rare entity in the oral and maxillofacial region. The most common site is the tongue, followed by the buccal mucosa. Osseous choristoma of the muscle is unusual and few cases have been described in the literature. No reports have described osseous choristoma arising on the medial side of the lateral pterygoid muscle. Herein, we report the first such case. A 61-year-old woman was referred to our facility for treatment of temporomandibular joint disorder. Computed tomography (CT) revealed two osseous lesions on the medial side of the lateral pterygoid muscle. Preoperatively, a three-dimensional (3D) life-sized model of the skull was fabricated from the CT imaging data. The 3D skull model was used to clarify the 3D positional relationships of the osseous lesions relative to the surrounding anatomical structures. Surgery to remove the osseous lesions was performed under general anesthesia. Unfortunately, only the larger of the two masses was able to be resected because of the risk of nerve and vascular injury. Histological examination revealed that the resected lesion comprised mature lamellar bone with regular osteocytes and no atypia. The diagnosis was multiple osseous choristomas based on the histological and clinical findings.

Myoepithelioma of the upper lip.

Myoepithelioma is a rare form of salivary gland tumor composed entirely of myoepithelial cells. This tumor was formerly considered to be a subtype of pleomorphic adenoma; however, in the 1991 World Health Organization classification, it is listed as an independent entity. The most favorable site of occurrence of myoepithelioma is the parotid gland. Here, we report an extremely rare case of myoepithelioma of the upper lip. A 56-year-old woman presented with a painless mass on her upper lip. Magnetic resonance imaging revealed a 23 mm × 18 mm well-defined ovoid tumor. A benign minor salivary gland tumor was clinically suspected, and the patient underwent complete resection of the tumor under general anesthesia. The tumor was histopathologically diagnosed as a benign myoepithelioma of the minor salivary gland. Immunohistochemically, the tumor cells were positive for S-100 protein, AE1/AE3, CAM5.2, CK7, vimentin, and calponin, confirming the morphologic diagnosis of myoepithelioma. The patient's postoperative clinical course was uneventful, and satisfactory results were obtained both functionally and esthetically. To the best of our knowledge, this is the sixth case of myoepithelioma of the upper lip reported in English-language research.

Usefulness of a nutrition assessment system for parenteral/enteral nutrition therapy.

Since a nutrition support team (NST) began to work in our hospital in March, 2003, we constructed our original nutrition assessment system that supports the prescription formulation of total parenteral nutrition (TPN). However, in daily NST activities, the re-evaluation of this system became necessary because of a high incidence of enteral nutrition (EN) and marked revisions in the dietary reference intakes in Japanese (7th revision). Therefore, we improved this system and added a prescription formulation support function that is also applicable to EN, and also added a function that automatically calculates the necessary doses of nutrients that tend to become deficient in patients with decubituses. This new system allowed the selection/evaluation of EN solutions in a short time with consideration of the 7th revision, and readily identified deficient nutrients and their levels in decubitus patients. We used this system in patients with high-level malnutrition complicated by decubituses and observed certain treatment effects.

Periodontal regeneration of transplanted rat molars after cryopreservation.

The effects of cryopreservation on periodontal regeneration of transplanted rat molars were investigated histologically and histochemically in rats. Bilateral first and second maxillary molars of 4-week-old Wistar rats were gently extracted and transplanted into the abdominal subcutaneous connective tissue immediately or after cryopreservation in liquid nitrogen overnight. Donor teeth were slowly frozen by a rate-controlling freezer (program freezer) using 5% dimethylsulfoxide (DMSO) and 6% hydroxyethyl starch (HES) as cryoprotectants. One-four weeks after transplantation, they were carefully excised with the surrounding tissues. Regeneration of acellular cementum, periodontal ligament, and alveolar bone were observed 2 weeks after immediate transplantation. The pulp was repaired by the ingrowth of granulation tissue from the root apex followed by the formation of calcified tissue. The regenerated periodontal ligament was positive for alkaline phosphatase (ALP). Small or mononuclear tartrate resistant acid phosphatase (TRAP) positive cells were scattered on the newly formed alveolar bone and on the hard tissue in the pulp, but there was no external or internal progressive root resorption at 4 weeks. Cryopreserved teeth had acellular cementum with a rough surface at 1 week, but with the increase of cementoblasts and the appearance of periodontal ligament and alveolar bone, the surface became smooth at 3 weeks. Epithelial rests of Malassez (ERM) also revived. After regeneration of the periodontal tissues at 4 weeks, there was no evidence of root resorption. Although the process proceeded slowly, the cryopreserved teeth showed the periodontal regeneration substantially similar to that of the immediately transplanted teeth without progressive root resorption, indicating that they could be applicable for clinical use.

Effects of occupational environmental controls and work management on chromosomal damage in dental technicians in Japan.

Dental technicians use various materials, particularly metal alloys and monomers and polymers based on methylmethacrylate. Environmental hygiene issues surrounding the work of dental technicians have been recognized. Despite the need for observance of occupational environmental controls and work management, compliance among dental laboratories appears to be low. We evaluated the relationship between genotoxic effects in dental technicians and occupational environmental controls and work management. We used cytokinesis-blocked micronuclei (CB-MN) frequencies in peripheral lymphocytes and metal levels in scalp hair. We also assessed nutritional factors related to anti-genotoxic effects using a self-administered brief diet history questionnaire. Study subjects were 54 male dental technicians and 38 male clerical workers. The parameters on the micronuclei (MN) frequency in dental technicians and clerical workers were analyzed by forward stepwise multiple regression analyses. Age (P < 0.01, ß = 0.561), occupation as a dental technician (P < 0.01, ß = 0.636) and aluminum levels in scalp hair (P < 0.05, ß = 0.213) were risk factors that significantly increased MN frequency. The significant parameters on the MN frequency in dental technicians were observance of hand-washing as work management (P < 0.01, ß = -0.304), work period (P < 0.01, ß = 0.509), germanium levels in scalp hair (P < 0.01, ß = -0.314) and workplace (P < 0.05, ß = 0.235). To avoid genotoxic effects, observance of occupational environmental controls and work management is necessary for dental technicians.

The use of enamel matrix derivative (Emdogain) for improvement of probing attachment level of the autotransplanted teeth.

The enamel matrix derivative (EMD, Emdogain) was used for the purpose to obtain the periodontal regeneration on the denuded root-surfaces of the donor teeth in two cases of the immediate tooth-transplantation. The root-surfaces at the cervical portion of the teeth were denuded because of extrusion. The healthy periodontium of each tooth remained at the apical portion of the roots. The denuded root-surfaces were cleansed before extraction. Then, the donor teeth were gently extracted with forceps, administered EMD, and transplanted so that the denuded surfaces were covered by gingival flaps. After the transplantation, the mean probing attachment level (PAL) improved 3.2 mm and 1.5 mm, respectively. The mean probing pocket depth was within normal level. The actual supporting areas of the roots of the transplanted teeth increased and the teeth worked as the abutments of prosthetic bridges.

Effects and distribution of the enamel matrix derivative Emdogain in the periodontal tissues of rat molars transplanted to the abdominal wall.

The enamel matrix derivative Emdogain (EMD) has been found to promote regeneration of lost periodontal tissues. We have studied the effects and distribution of EMD in the periodontal tissues of maxillary rat molars transplanted to a subcutaneous position in the abdominal wall. The molars were transplanted with or without EMD either immediately after extraction or after drying for 30 min. After 2 days, 1, 2 or 4 weeks the rats were killed and the teeth were examined by means of light microscopy and immunohistochemistry with anti-amelogenin antibodies. Teeth transplanted immediately after extraction showed formation of alveolar bone separated from the dental roots by a periodontal space, regardless of the use of EMD. Among the teeth that were transplanted with EMD after drying for 30 min, new alveolar bone was formed in five out of eight teeth after 2 and 4 weeks. None of the teeth that were dried for 30 min and transplanted without EMD showed alveolar bone formation. Only one tooth transplanted with EMD showed root resorption after drying, while resorption was noted in all teeth transplanted without EMD. All teeth that were transplanted with EMD and none of the teeth that were transplanted without EMD showed an immunohistochemical reaction for amelogenin. After 2 days, amelogenin was precipitated on all surfaces exposed at the transplantation procedure. Later, the immunoreactive material was redistributed to cells at the root surface, where it was still demonstrable after 4 weeks. In conclusion, EMD is accumulated in cells at the root surface and promotes regeneration of the periodontal tissues of the transplanted teeth. It also seems to promote healing of root resorption.