Long-term follow-up after reimplantation of tumorous mandible bone treated with combination of decalcification and lyophilization.

Mandibular resection requires reconstruction, with often unsatisfactory morphofunctional results. Reimplantation of the resected mandible itself is one of ideal solutions to this problem. However, both devitalization of tumor cells involved in resected bone and preservation of osteoinductive activity are required for successful results. Lyophilization appears to enable devitalization of tumor cells, and decalcified bone implants are likely to have osteoinductive potential. Accordingly, we speculated that decalcification and lyophilization of resected bone would be an appropriate method for mandibular reconstruction. However, there is no study on the reimplantation of mandibles treated with these methods to date. The purpose of this study was to estimate the long-term follow-up of reimplanted mandibles treated with decalcification and lyophilization. Presented here are 2 patients of reimplanted mandibles treated by decalcification and lyophilization who were followed up for 8 and 9 years. We observed a good incorporation of the graft in 1 case, but severe absorption in the other. Our results suggest that treatment with decalcification and lyophilization is 1 strategy for reimplantation of the resected bone in mandibular reconstruction, but further study is needed to prevent absorption of the reimplanted bone over the long term.

Reconstruction of the mandible bone by treatment of resected bone with pasteurization.

The results of long-term follow-up for reimplantation of the mandibular bone treated with pasteurization are reported. Mandibulectomy was performed for mandibular malignancy in 3 cases. The resected bones were subsequently reimplanted after treatment with pasteurization in 3 cases to eradicate tumor cells involved in the resected bone. Although postoperative infection was observed in 2 of 3 cases, reimplantation of the resected mandibular bone treated by pasteurization was finally successful. Ten to 22 years of follow-up was carried out. Pasteurization was able to devitalize tumor cells involved in the resected bone and to preserve bone-inductive activity. Reimplantation of pasteurization could be a useful strategy for reconstruction of the mandible in patients with mandibular malignancy.

Expression of heat shock protein 47 in the fibrous tissue adjacent to mouse tumour subjected to photodynamic therapy.

The reaction of normal fibrous tissue adjacent to tumours subjected to photodynamic therapy (PDT) was investigated by assessment of the immunohistochemical expression of heat shock protein 47 (HSP47) and proliferating cell nuclear antigen (PCNA), as well as by immunoblot analysis of procollagen type I. PDT was administered to NR-S1 mouse squamous cell carcinoma or normal mouse skin. Each of four mice was investigated at several time points after receiving PDT. The levels of HSP47 expression were determined by computer-assisted image analysis. The expression of procollagen type I in the fibrous tissue adjacent to the tumours was examined by immunoblot analysis at intervals of 24 and 48h after PDT. The expression of HSP47 was first detected 6h post-PDT in the tumour-bearing mice, but no such expression was observed in the normal mice. It was also revealed that, after PDT, the fibroblast PCNA labeling indices at 24, 48, and 72h were significantly higher in both the tumour-bearing and the normal mice than in the control animals that did not receive PDT. Furthermore, procollagen type I was detected in the fibrous tissue adjacent to the tumours at 24 and 48h after PDT, but was not detected in the fibrous tissue adjacent to tumours of mice that did not receive PDT. Therefore, the present results suggest that PDT enhances the synthesis of collagen type I in the fibrous tissue adjacent to NR-S1 squamous cell carcinoma in mice, which contributes to the resultant encapsulation of such tumours.

Enhanced susceptibility of mouse squamous cell carcinoma to photodynamic therapy combined with low-dose administration of cisplatin.

PURPOSE: We have investigated the antitumor effect of photodynamic therapy (PDT), using Photofrin as the photosensitizer, combined with low-dose cisplatin (CDDP) on NR-S1 mouse squamous cell carcinoma. MATERIALS AND METHODS: CDDP (5 mg/kg body weight) was injected intraperitoneally either 1 hour or 3 hours prior to PDT or immediately afterward. Twenty-four hours after each protocol, the antitumor effects were evaluated by percentage area of the tumor necrosis in hematoxylin-eosin stained specimens as well as terminal deoxynucleotidyl transferase-mediated d-UTP nick-end labeling indices. Furthermore, the tumor sizes were evaluated at 3, 7, and 10 days after each protocol. RESULTS: The antitumor effect of PDT was enhanced by administration of CDDP 3 hours before PDT, whereas the administration of CDDP 1 hour before PDT or immediately after PDT did not potentiate a PDT antitumor effect. CONCLUSION: Administration of low-dose CDDP 3 hours before PDT appears to be a useful treatment modality.

Fractionated photodynamic therapy for a human oral squamous cell carcinoma xenograft.

The aim of this study was to define the appropriate fractionation interval between photodynamic therapies (PDTs) for enhanced anti-tumour effects on human oral squamous cell carcinoma (HOSCC). Reoxygenation of HOSCC and the proliferative kinetics of the tumour cells following PDT exposure were evaluated in terms of immunohistochemical expression of vascular endothelial growth factor (VEGF) and the proliferating cell nuclear antigen (PCNA). The immunohistochemical expression of VEGF was quantitatively determined by computer-assisted image analysis. The VEGF expression and the PCNA labeling indices (LIs) of the tumour cells were assessed at varying time intervals after PDT. No significant differences were observed in PCNA LIs between the control group and experimental groups at 24, 48, and 72 h after PDT. The expression of VEGF after PDT exposure was demonstrated to be higher in the experimental group at 6 h than the control group, and then was comparable at 24 h between the both groups. These results indicate that the tumour cells surviving from PDT have proliferative potential, and that oxygenation in tumours subjected to PDT may be recovered after 24 h. In the next experiment, two protocols of laser irradiation in PDT were assessed on the basis of tumour volume between fractionated exposure with a 24-h interval and continuous exposure. Regrowth of the tumour was significantly suppressed by fractionated PDT. We propose here that fractionated light exposure with a 24-h interval should be utilized in PDT for an enhanced anti-tumour effect.

A case of mucoepidermoid carcinoma with melanin pigmentation manifested in the palate.

This paper describes the first documented case of mucoepidermoid carcinoma (MEC) with melanin pigmentation manifested in the palate. Histopathological sections showed a neoplasm composed of epidermoid, mucous-producing and intermediate cells. Numerous large cells contained dark pigmented materials. Fontana Masson staining revealed dendritic melanocytes and melanin granules. HMB-45, Melan A and S-100 protein were all positive for melanocytes. Histopathological examination was not typical for malignant melanoma; the lesion was diagnosed as a low-grade MEC with melanin pigmentation.

Morphometric analysis of mouse tumor nuclei subjected to photodynamic therapy.

PURPOSE: The diachronic changes in nuclei in tumor cells subjected to photodynamic therapy (PDT) were investigated using computer assisted analysis to elucidate the degeneration process of tumor cell nuclei. MATERIALS AND METHODS: A photosensitizer was injected intraperitoneally to mice bearing NR-S1 mouse squamous cell carcinoma in the dorsum 48 hours before laser irradiation. Mice were sacrificed at intervals of 0, 0.5, 1.5, 2.5, 6, 24, 48, and 72 hours after PDT, and tumors were excised. Neither photosensitizer nor laser irradiation was administered to control mice. A 4-mum section was prepared from each specimen, followed by hematoxylin and eosin staining. The nuclei of the tumor cells were examined under a light microscope. The mean nuclear area and coefficient of variation of the nuclear area of 100 nuclei per slide were calculated. RESULTS: Both nuclear area and coefficient of variation of the nuclear area were significantly lower in the experimental groups nuclei than in control mouse nuclei at 24 and 48 hours after PDT. CONCLUSION: These results suggest that maximum damage to tumor nuclei occurs between 24 to 48 hours after PDT.

Inhibitory effect of heat shock protein 70 on apoptosis induced by photodynamic therapy in vitro.

We examined the apoptotic effects of photodynamic therapy (PDT) in leukemia cells (HL60) and lymphoma cells (Raji). Moreover, we also investigated the relationship of apoptosis induced by PDT to heat shock protein (HSP) expression. To induce 80% of cell death by PDT, HL60 cells required 6 microg/mL and Raji cells required 9 microg/mL of Photofrin. PDT induced apoptosis in 77.2% of HL60 and in 0.4% of Raji at lethal dose (LD80) conditions. The cell line in which apoptosis is predisposed may be more susceptible to PDT compared with the cell line in which necrosis is predisposed. Furthermore, HSP-70 was expressed constitutively in Raji cells but not in HL60 cells. Heat treatment of HL60 cells induced expression of HSP-70 and resulted in significant reduction of PDT-mediated apoptosis. From the results of this experiment, it is suggestive that HSP-70 contributes to inhibition of apoptosis mediated by PDT.

Expression of vascular endothelial growth factor and prognosis of oral squamous cell carcinoma.

The correlation between expression of vascular endothelial growth factor (VEGF) and prognosis for oral squamous cell carcinoma was investigated. Tissue samples of oral squamous cell carcinoma were obtained from 63 patients. Of these patients, 11 had stage I, 17 had stage II, 9 had stage III, and 26 had stage IV tumours. Immunohistochemical expression of VEGF was quantitatively determined by computer-assisted image analysis. The value of VEGF expression was significantly higher for the patients with poor prognosis than for those with good prognosis (P=0.0423). Regarding regional lymph node metastasis, VEGF showed no significant difference between metastasis positive and negative patients. Expression of VEGF may thus be a prognostic marker for oral squamous cell carcinoma.

Predictability of lymph node metastases by preoperative nuclear morphometry in squamous cell carcinoma of the tongue.

AIM: This study was undertaken to assess the predictability of lymph node metastases by analyzing preoperative nuclear morphometry of squamous cell carcinoma of the tongue. METHODS: Twenty-eight cases of well-differentiated squamous cell carcinoma (13 cases with metastasized lymph nodes, 15 node-negative cases) were examined. Using a computerized image system, the mean nuclear area, the nuclear perimeter, the circular rate, the largest to the smallest dimension ratio (LS ratio) of the nuclei, and the coefficient of variation of the nuclear area (NACV) were measured. The relationship between these results and the lymph node involved was evaluated retrospectively. RESULTS: The nuclear area and perimeter were significantly higher in cases with metastasized lymph nodes than in node-negative cases (P<0.05). The circular rate was also higher in cases with no metastasized lymph nodes than in node-positive cases (P<0.05). The LS ratio was higher in cases with metastasized lymph nodes than in node-negative cases (P=0.072). The NACV value was also higher in cases with metastasized lymph nodes than in node-positive cases, which showed no significant differences (P=0.322). CONCLUSIONS: Preoperative quantitative estimations of nuclear features could provide a feasible criterion for the prediction of lymph node metastases in squamous cell carcinoma of the tongue.

Preoperative assessment of the relationship between the mandibular third molar and the mandibular canal by axial computed tomography with coronal and sagittal reconstruction.

OBJECTIVE: We sought to evaluate the relationship between the mandibular third molar and the mandibular canal by using axial computed tomography with coronal and sagittal reconstruction for third molar surgery. STUDY DESIGN: Forty-seven impacted third molars in 41 patients were found in close association with the mandibular canal during a panoramic radiographic assessment. The relationship between the mandibular third molar and the mandibular canal was evaluated by using computed tomography and compared in terms of operative exposure of the inferior alveolar nerve and postoperative labial dysesthesia. RESULTS: Twenty-four (51%) mandibular canals were buccal relative to the third molar, 12 were lingual, 9 were inferior, and 2 were between roots. At the time of the surgical procedure, the inferior alveolar nerve was visible in 7 patients. Postoperative lower lip dysesthesia occurred in 1 patient whose mandibular canal was in the lingual position. CONCLUSIONS: Axial computed tomography with coronal and sagittal reconstruction provides useful information to surgeons regarding the relationship between the mandibular third molar and the mandibular canal.

The free deltoid flap: microscopic anatomy studies and clinical application to oral cavity reconstruction.

The deltoid free flap is a fasciocutaneous flap that should be thin, hairless, of an adequate size, and capable of sensory reinnervation. Because of its excellent color-matching and texture-matching characteristics, it has recently been widely used for the reconstruction of soft-tissue defects during oral and maxillofacial surgery. Furthermore, a characteristic of oral and maxillofacial soft-tissue defects is that they are not large; therefore, flap size will be small, allowing the donor site to be directly closed. Because of natural variation in parts of the anatomy, there has sometimes been great difficulty in clinical application. The authors decided to study this by performing anatomical studies of the deltoid region on 21 cadavers. The result indicates that the pedicle of the deltoid free flap penetrates the "quadrangular space" in 90 percent of cases but passes and does not penetrate the quadrangular space in the remaining cases. The authors also confirmed that the skin has a vascular network comprising five layers and, furthermore, that the vascular network of the deep fascia is dense. The authors also report six cases of its clinical use complicated by anatomic variation and local infection in which the deltoid flap showed a completely successful outcome.

[A case report of tongue squamous cell carcinoma showing a complete response to TS-1].

A 75-year-old female with squamous cell carcinoma in the left margin of the tongue (T2N0M0) was referred to our hospital. She was treated with oral administration TS-1 80 mg/day as preoperative chemotherapy. After commencement of TS-1 administration, the tumor size was reduced at 1 week and had disappeared clinically at 4 weeks. Oral administration of TS-1 was done in 2 courses at the same dose. After two courses, histological examination reveled a complete disappearance of the cancer cells. No adverse effects were seen during the treatment period. She remains under oral administration of UFT for maintenance chemotherapy and there is no evidence of recurrence of the tumor.

Antisense oligonucleotide against collagen-specific molecular chaperone 47-kDa heat shock protein suppresses scar formation in rat wounds.

The 47-kDa heat shock protein (HSP47) is a molecular chaperone specifically targeting the processing and quality control of collagen molecules. This study was performed to investigate whether antisense therapy preventing HSP47 expression might affect the scar formation occurring during wound healing of skin. In wound healing of neonatal rat skin, the number of HSP47-positive cells and the amount of HSP47 protein consistently increased up to 7 days after surgical wounding. The increase in HSP47-positive cell number and protein content was efficiently suppressed by daily injections of HSP47-antisense deoxynucleotide (30 nmol) for 7 days. This treatment also suppressed the accumulation of collagen type I in the wound. Moreover, the disorder of collagenous fibers was relieved in the healed portion of the wounds subjected to the antisense treatment. Taken together, the authors propose that HSP47 is an important determinant in scar formation and that the antisense treatment against HSP47 gene may have a therapeutic potential to suppress the scar formation of skin.

Hyperthermic photodynamic therapy combined with topical administration of OK-432 in the mouse carcinoma.

This study investigated the combined effect of photodynamic therapy (PDT) using high power laser irradiation (HPL), which generates both a hyperthermic and a photodynamic effect, and OK-432 on NR-S1 mouse squamous cell carcinoma. The photosensitizer (haematoporphyrin oligomers 20 mg/kg BW) was injected to the mice intraperitoneally 48 h before laser irradiation. OK-432 was injected into the tumour 3 h prior to laser irradiation. The experimental protocols consisted of HPL-PDT with or without OK-432, low power laser PDT with or without OK-432, HPL alone and OK-432 alone, and a control group. The tumour necrotic area was determined, and tumour sizes were measured 3, 7 and 10 days after each protocol. The anti-tumour effect of HPL-PDT was enhanced by preadministration with OK-432. Treatment with OK-432 alone or hyperthermic HPL irradiation presented little anti-tumour effect. HPL-PDT in combination with OK-432 topically administered 3 h before photo-irradiation is considered to be a promising therapeutic modality.