Hiroshige Chiba

Multi-center intervention study on glycohemoglobin (HbA1c) and serum, high-sensitivity CRP (hs-CRP) after local anti-infectious periodontal treatment in type 2 diabetic patients with periodontal disease

The purpose of this study was to examine whether periodontal treatment incorporating topical antibiotic therapy affects on levels of glycohemoglobin (HbA1c) and serum high-sensitivity C-reactive protein (hs-CRP) in type 2 diabetic patients with periodontal disease, and to explore the relationship between CRP and glycemic control. The whole intervention group (n=32), which underwent anti-infectious periodontal treatment, showed only transient reduction in HbA1c levels without any change in hs-CRP, while the control group (n=17) did not show any changes in HbA1c or hs-CRP. Multiple regression analysis of all subjects revealed that BMI and change in hs-CRP correlated significantly with the reduction of HbA1c at 6 months after the periodontal treatment. Based on the results of multiple regression analysis, the intervention group was subdivided into two groups: those in which hs-CRP levels decreased (CRP-D group), and those in which hs-CRP levels unchanged or increased (CRP-N group) (n=16, respectively), and re-analysis was conducted based upon these subgroups. In the CRP-D subgroup, HbA1c was significantly reduced at the end of the study, but it did not decrease in the CRP-N subgroup. The decrease of HbA1c in the CRP-D subgroup following periodontal treatment was significantly greater than that in the CRP-N subgroup. BMI of each group remained unchanged in this study at the end of the study. Thus, the results suggested that periodontal treatment with topical antibiotics improves HbA1c through reduction of CRP, which may relate to amelioration of insulin resistance, in type 2 diabetic patients with periodontal disease.

Bcl-xL confers multi-drug resistance in several squamous cell carcinoma cell lines

Abstract Carboplatin (CBDCA) alone or in combination with irradiation and other chemotherapeutic agents has been used for the treatment of oral squamous carcinoma. However, there are some limitations for such therapy because of inherent or acquired resistance to CBDCA. To gain some insights into the association of CBDCA resistance with Bcl-2 family level or p53 status, we established eight carcinoma cell lines, consisting of two resistant (MIT8, MIT16), two sensitive (MIT6, MIT7), and four intermediate lines. All of the five cell lines with p53 mutation belonged to the resistant ∼ intermediate group, whereas two of three other lines with wild-type p53 were in the sensitive group. Interestingly, both of the two resistant cell lines showed elevated levels of Bcl-x L , almost double that of sensitive line (MIL5), whereas either Bcl-2 or Bax-α level did not correlate with the CBDCA-resistance. To further verify the association between the Bcl-x L level and the drug resistance, two transformants (x L -3, x L -6) overexpressing Bcl-x L in the CBDCA-sensitive cell line MIT7 were established using the gene transfer method. Both clones showed resistance to multiple chemotherapeutic agents, including CBDCA, actinomycin D, etoposide, and mitomycin C. Moreover, MIT8 and MT16 also displayed cross-resistance to these agents. These findings suggest that Bcl-x L may function as one of the key components conferring multiple drug-resistance in squamous cell carcinomas.

Cleavage of Bax-α and Bcl-xL during carboplatin-mediated apoptosis in squamous cell carcinoma cell line

Abstract Although carboplatin (CBDCA) has been used for the treatment of several types of tumors, the complete response rate has been limited, probably because of inherent or CBDCA-induced resistance. As a first step to overcome these problems, we tried to elucidate the mechanisms of CBDCA-mediated cytotoxicity in the squamous cell carcinoma cell line MIT7. The treatment of cells with CBDCA resulted in apoptosis in a dose-dependent manner, as assessed by the propidium iodide staining method and DNA degradation in a nucleosomal pattern. The induction of apoptosis was accompanied by the decline of mitochondrial membrane potential (Δψm ) at 12 h following CBDCA stimulation. Variant forms of p18 Bax-α and p16 Bcl-xL were generated with the down-regulation of both Bax-α (p21) and Bcl-xL (p31) at 36 and 48 h following CBDCA stimulation, suggesting that the modulation of Bcl-2 family proteins Bax-α and Bcl-xL play some role in CBDCA-mediated apoptosis. The activation of caspase-3 and -8 occurred at 12 and 24 h following the stimulation, respectively. The pretreatment of cells with pan-caspase inhibitor Z-VAD-fmk markedly prevented CBDCA-mediated cytotoxicity/apoptosis and the modulation of Bcl-2 family proteins (generation of p18 Bax-α and p16 Bcl-xL ) with only slight prevention of decline of Δψm. Taken together, these results may suggest that activation of several caspases, including caspase-3 and -8, plays some role in CBDCA-mediated apoptosis, probably through the modification of Bcl-2 family proteins, Bax-α and Bcl-xL. Moreover, caspase activation may occur downstream of membrane depolarization.

Significance of Heterogeneous Nuclear Ribonucleoprotein B1 as a New Early Detection Marker for Oral Squamous Cell Carcinoma

The development of an early tumor detection marker for oral cancer is an obvious need due to the high recurrence rate and poor survival rate. Based on our previous report that overexpression of heterogeneous nuclear ribonucleoprotein (hnRNP) B1 protein was found in 100% of squamous cell carcinomas of human lung, we applied the same immunohistochemical method, using anti‐hnRNP B1 antibody, to human oral squamous cell carcinoma (OSCC). Seven human tissue sections of OSCC showed strong staining with anti‐hnRNP B1 antibody, and hnRNP B1 protein of 37 kDa was identified in protein fractions isolated from six of the cancerous tissue sections, while it was not found in adjacent noncancerous tissue. Moreover, three non‐homogeneous (nodular) leukoplakia sections showed significant anti‐hnRNP B1 staining. The results suggest that this antibody detects precancerous lesions as well as advanced lesions (stages I to IV) of OSCC. We also present positive results of cytodiagnosis for two smear specimens. All of the above results indicate that hnRNP B1 is a new and useful marker for early detection of OSCC.

Clinical application of a custom-made bioresorbable raw particulate hydroxyapatite/poly-l-lactide mesh tray for mandibular reconstruction

Mandibular reconstruction using particulate cancellous bone and marrow (PCBM) allows functional oral reconstruction. Although ready-made titanium trays are the most common material used in this method, they have some disadvantages such as difficulty in making them form a suitable contour for the defect, and the need for removal. A forged composite of raw particulate hydroxyapatite (HA)/poly-l-lactide (PLLA) is a bioresorbable material that is stronger than pure PLLA and induces bone formation more rapidly. We present two cases successfully treated with custom-made bioresorbable HA/PLLA mesh trays for mandibular reconstruction. A 29-year-old woman with recurrent ameloblastoma and a 66-year-old man with a recurrent keratinized odontogenic tumor of the mandible gave informed consent for this reconstruction technique. Mesh sheets of HA/PLLA were customized by a rapid prototyping method based on computed tomography (CT) data. Marginal resection of the tumor was carried out, and PCBM was harvested from the bilateral posterior iliac crests. PCBM and platelet-rich plasma were transferred to the tray, and the tray was fixed rigidly with HA/PLLA screws. In the second case, dental implants were inserted. There has been no bone resorption for over 2 years since reconstruction in these two cases, and the inserted dental implants have been free from any complications 1 year after loading. The average CT value in Hounsfield units (HU) of the implant sites of two cases was 790. In conclusion, the customized HA/PLLA tray was easily adapted to the mandible, and fine bone quality was obtained. These cases show that this tray system contributed to functional oral rehabilitation with dental implants.

Brain abscess in which Porphyromonas gingivalis was detected in cerebrospinal fluid

In this paper, we report one case of severe brain abscess in which Porphyromonas gingivalis was detected in the spinal fluid.

Effect of glycemic control on periodontitis in type 2 diabetic patients with periodontal disease

Diabetes mellitus and periodontitis are closely related. A huge number of reports has addressed the effect of periodontal intervention therapy on glycemic control, but no reports have addressed the effect of glycemic intervention therapy on periodontal disease in type 2 diabetic patients. The aim of this study was to examine the effect of improved glycemic control by glycemic intervention therapy on periodontitis in type 2 diabetic patients.

Epidemiological study of malignant tumors in the oral and maxillofacial region: survey of member institutions of the Japanese Society of Oral and Maxillofacial Surgeons, 2002

We studied 1809 patients with oral cancer who visited and were treated, in 2002, at the 148 institutions certified as training facilities by the Japanese Society of Oral and Maxillofacial Surgeons. Of these institutions, 39 are dental university hospitals, 44 are medical university hospitals, 64 are general hospitals, and for 1 institution, the classification was not known. The patients consisted of 1071 (59.2%) males and 738 (40.8%) females (male: female ratio, 1.45:1), who had a average age of 65.2 years. The tongue (40.2%) was the most common site affected, followed by the gingiva (32.7%), buccal mucosa (10.1%), and oral floor (9.0%). There were 6 cases of multiple intraoral cancers. On histopathological examinations, squamous cell carcinoma (88.7%) was the most common type found, followed by adenoid cystic carcinoma (2.1%), and mucoepidermoid carcinoma (1.7%). Cases classified as T2N0 were the most common (32.1%), followed by T1N0 (21.4%), T4N0 (8.0%), and T2N1 (7.6%). Distant metastasis occurred in 17 patients (1.0%). Nonepithelial tumors, among which malignant melanoma was the most common type, accounted for 1.8% of the tumors. The sizes of the nonepithelial malignant tumors ranged from 1.0 to 7.0 cm, with an average size of 3.7 cm.

Expression of mouse osteocalcin transcripts, OG1 and OG2, is differently regulated in bone tissues and osteoblast cultures.

Abstract. Osteocalcin is a noncollagenous protein that is abundant in mineralized bone matrix. Mice have a gene cluster of osteocalcin that consists of OG1, OG2, and ORG. We established a new method to directly analyze the expression levels of OG1, OG2, and ORG mRNAs relative to total osteocalcin mRNA. They were amplified as 371-bp fragments by reverse transcription-polymerase chain reaction (RT-PCR) at the same time using common primers, digested with ApaLI, and separated in a polyacrylamide gel. ApaLI digestion did not affect the mobility of the OG1-derived 371-bp fragment, whereas both 371-bp fragments, derived from OG2 and ORG, were digested into 350 bp. Total RNA prepared from mouse bone was then subjected to RT-PCR followed by ApaLI digestion. OG1 and OG2 mRNAs were found to be expressed at ratios of 80%–86% and 14%–20%, respectively, to the total osteocalcin mRNA in mouse bone. The ratios were almost constant in various bones in vivo, independent of the animals genetic background, age, or gender, or different parts of bone. RT-PCR using specific primers revealed that mouse bone tissues strongly expressed osteocalcin mRNA derived from OG1 and OG2, but not ORG. In contrast, cells cultured in vitro showed different expression ratios of osteocalcin mRNA: 53%–65% for OG1 and 35%–47% for OG2 to the total osteocalcin mRNA in the osteoblast cell line and primary osteoblasts in culture even though they formed many mineralized bone nodules. Similar results were obtained in both KS483 osteoblasts and C2C12 myoblasts, when they were cultured with bone morphogenetic protein-2 (BMP-2) to induce osteocalcin mRNA. Taken together, these findings indicate that OG1 is the predominant transcript among the three osteocalcin genes in mouse bone in vivo. It is also suggested that the expression of OG1 and OG2 is regulated differently in bone tissues and osteoblast cultures.

Diagnosis of intra-oral MALT lymphoma using seminested polymerase chain reaction

Diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma based on histological examination alone is difficult. We report three patients with histologically suspected MALT lymphoma who developed lymphoproliferative lesions of the sublingual gland. Seminested polymerase chain reaction (PCR) analysis applied to formalin-fixed and paraffin-embedded specimens showed clonal rearrangement of immunoglobulin heavy chain genes in two patients and a polyclonal characteristic in one. The clinical findings and Southern blot analysis confirmed the accuracy of the diagnosis. The molecular method described can be applied routinely to processed specimens to obtain helpful information for the diagnosis of low-grade malignancies of lymphoproliferative disorders, such as MALT lymphoma.