The susceptibility of a mouse squamous cell carcinoma cell line to lymphokine activated killer (LAK) cells and cytotoxic T lymphocytes (CTL) was examined in terms of major histocompatibility complex (MHC) class I expression after various treatments with γ-rays and interferon-γ(IFN-γ). The original NR-S 1 cells were squamous cell carcinomas of C 3 H/He mice; these were used as target cells. The NR-S 1 cells were previously treated with (1) irradiation with 10 Gys of γ-rays, (2) 100 U/ml of IFN-γ, (3) a combination of γ-rays and IFN-γ, or (4) citric acid at pH 3. The highest expression of MHC class I was obtained in the combination group, followed by the IFN-γ and γ-ray groups. The lowest expression was obtained in the citric acid group. As for evidence of adhesion molecules, ICAM-1 was enhanced slightly in the IFN-γ group, but ICAM-2 was not enhanced in any group.
LAK cells were obtained from the splenic lymphocytes of C3H/He, C57BL/6 or BALB/c mice, and incubated with rIL-2 for 3 days. These LAK cells showed 17-27% cytotoxicity against P815 cells, 69-75% against YAC-1 cells, and about 30% against untreated NR-S 1 cells. The target cells in the combination group were the most resistant to LAK cells, and those in the citric acid group were more sensitive than the untreated cells. There was no significant difference in activities among the three strains of mice. Anti-CD 8 antibody or anti-asialo GM 1 antibody was intra-peritoneally administered to these three strains of mice, and the spleen cells were collected. The cytotoxicity of LAK cells from the mice given anti-CD 8 antibody was similar to that of the untreated mice.
In contrast, treatment with anti-asialo GM 1 antibody decreased the cytotoxic activities in all groups. These findings suggest a negative correlation between MHC class I expression and the susceptibility of NR-S 1 to LAK cells. The killer activity was predominantly due to asialo-GM1⁺ cells.
CTL were prepared from untreated C3H/He mice spleen cells. They were incubated with inactivated NR-S 1 cells for 7 days and cultured again with rIL-2 (5 JRU/ml) for 7 days. Although the cytotoxicity of CTL was lower than the LAK activity, it increased in direct proportion to the expression of MHC class I. These findings suggest that CTL would be most effective for adoptive immunotherapy when combined with radiotherapy or cytokine therapy.

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The BCL-2 gene product has been reported to block apoptosis and to contribute to tumorigenecity. This study examined whether BCL-2 expression was involved in the development of ameloblastoma. We carried out immunohistochemical studies of 20 cases of ameloblastoma using anti-BCL-2, anti-PCNA antibodies, and the TUNEL method to identify DNA fragmentation in situ. By immunohistochemical techniques, BCL-2 expression was observed in all specimens except those that were decalcified.
Localization of BCL-2 was found at nuclei and cell membranes of the peripheral layer. The TUNEL method showed positive reactions at epithelium with squamous metaplasia and a trend toward cornification. These results suggested that the BCL-2 gene product might contribute to the development of ameloblastoma by the blocking apoptosis at the peripheral layer of the epithelial islets.

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CD44 is an important adhesion molecule that serves as a cell surface receptor for hyaluronic acid and as a homing receptor for lymphocytes.
In this study, we immunohistochemically investigated the expression of CD44 in 12 human temporomandibular joint (TMJ) discs.
Four types of CD44 expression were found:(1) around round cells at the surface of the synovial membrane;(2) around round cells in the connective tissue, apparently indicating homing receptors for lymphocyte;(3) at the stroma of the synovial membrane; and (4) beneath vascular epithelial cells, apparently indicating cell surface receptors for hyaluronic acid.
No appreciable expression of CD44 was observed in specimens taken from a patient with an immobile disc because of contralateral TMJ ankylosis.

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We performed arthrocentesis (upper joint compartment irrigation) in 28 patients with unilateral closed lock. In order to study indications for arthrocentesis, we statistically analysed clinical findings, which included age, duration of closed lock, maximal mouth opening (MMO), intensity of pain (VAS), and radiographic and arthrotomographic findings, in patients with a good clinical outcome and those with a poor outcome.
The results were as follows.
1. There was no significant difference between the groups in mean age, MMO, or VAS before treatment.
2. The mean duration of closed lock in poor responders to treatment (22±18 months) was significantly longer than that in good responders (7.4±5.0 months)(t-test, P<0.01).
3. The incidence of morphological changes of the mandibular condyle in poor responders (62.5%) was significantly higher than that in good responders (16.7%)(χ²-test, P<0.01).
4. The incidence of disk deformity in poor responders (87.5%) was significantly higher than that in good responders (50%)(χ²-test, P<0.05).
The results suggest that arthrocentesis is indicated in patients with a short (less than one year) duration of closed lock who have no morphological changes of the mandibular condyle or disk deformity.

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Basic studies were performed in vitro and in vivo to evaluate a new type of calcium phosphate cement. This time we studied an a -tricalcium phosphate (α-TCP)/dicalcium phosphate dibasic (DCPD)/tetracalcium phosphate monoxide (TeCP) system that was developed by improving an α-TCP/DCPD system. Columns of hardened cement were used for assess the relation between compressive strength and soaking time in simulated body fluid (SBF). In addition, disks of the hardened cement were soaked in SBF and implanted in subcutaneous tissues of rats to evaluate changes in the cement by means of XRD and SEM.
As compared with the former system, higher compressive strength was obtained and maintained longer, apparently because of a higher powder/liquid ratio. In XRD and SEM analyses, the cement showed HA formation after mixing, and transformation of powder components to HA as well as HA precipitation on the disks were seen both in vitro and in vivo. However, the degrees of transformation and precipitation differed between in vitro and in vivo. Histologically, the implanted disks in rats provoked the same reactions of the surrounding tissues as HA ceramics implanted in soft tissues. Significant resorption of the cement was not found histologically. However, there were signs of resorption in vivo, including SEM findings of increased surface porosity after implantation and histological evidence of multinucleate giant cells on the cement surface. Further studies of cement resorption should be performed over longer periods, in bone tissues, or both.

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A new system of calcium phosphate cement, consisting of α-tricalcium phosphate (α-TCP), dicalcium phosphate dibasic (DCPD), and tetracalcium phosphate (TeCP), was developed. In this study, columns of hardened cement were implanted on the inferior surface of rabbit mandibles and into the back muscle for 6 months, 1 year, and 1.5 years to evaluate responses of the surrounding tissues and changes in the materials in vivo.
Histologic, microradiographic and scanning electron micrographic investigations of the implants in mandibles revealed active bone formation along the surface of the cement and direct contact between new bone and the materials. The cement showed surface irregularities created by resorption, which were remarkable on surfaces bounded by soft tissue.
Histologic and microradiographic studies of the implants in back muscles showed the presence of a thin fibrous capsule without inflammatory cell infiltration; resorption was usually more remarkable than that with materials implanted in mandibles.
The results of this study suggest that the hardened cement is resorbable in vivo and is highly biocompatibile with living tissues.

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Dual-energy quantitative computed tomography (DEQCT) is useful in the quantitative analysis of bone mineral content (BMC). This study describes the use of DEQCT in the quantitative evaluation of the BMC of particulate cancellous bone and marrow grafted to the basal maxillary sinus and alveolar cleft defects.
Several regions of interest (ROI) were used for analysis. In all ROI, BMC increased after the graft in all patients. An irregular ROI may be best suited for the evaluation of whole grafted bone. If the placement of root form implants is planned, evaluation of a circular ROI is useful. On the other hand, a CT-profile permitted the localization of BMC.

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Six healthy volunteers underwent dynamic enhanced magnetic resonance (MR) imaging to evaluate the enhancement pattern of normal structures of the oral and maxillofacial region. Dynamic enhanced MR imaging was performed with a 1.5-T superconducting MR Imager and a T 1 weighted spin echo sequence in the coronal plane (five volunteers were evaluated at the mandibular molar plane, and one at the submandibular gland). The results of these study were as follows:
1. The mucosal surface of the inferior and middle conchae, nasal wall, hard palate, and tongue showed a short time to peak and a gradual wash-out pattern.
2. The submandibular gland and the sublingual space, which contained the sublingual gland, showed a short time to peak and a rapid wash-out pattern.
3. The intrinsic muscles of the tongue appeared as structures with higher signal intensity than extrinsic muscles on precontrast scans, and showed a long time to peak and a gradual wash-out pattern.
4. The bone marrow of the mandible, subcutaneous fat, and genioglossus muscle showed a pattern of no change.

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Metallothionein (MT), a low molecular weight metal binding protein, has been implicated in the proliferative activity of carcinoma cells. In this report, tissue sections from six cases of mucoepidermoid carcinoma of the oral mucosa were studied immunohistochemically to characterize the expression of MT and to evaluate implications for tumor histological differentiation. The mean percentage of MT positive cells in the mucoepidermoid carcinomas (3.1%, n=6) was significantly lower than those in normal oral mucosa (38.0%, n=10) and oral squamous cell carcinomas (56.0%, n=7). When analyzed according to cell type of the mucoepidermoid carcinomas, 1.1% of the mucous cells, 4.7% of the epidermoid cells, and 1.7% of the intermediate cells were positive for MT immunoreactivity. The incidence of MT expression was significantly lower than that of the normal oral mucosa and the oral squamous cell carcinomas (p<0.001).

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An ectopic adrenocorticotropic-hormone (ACTH)-producing tumor of the maxillary sinus is described. A 50-year-old man was referred to our department from the department of internal medicine because of an abnormal accumulation in right maxilla on ^99mTc scintigraphy. Examination of a biopsy specimen revealed small cell carcinoma (ectopic ACTH producing). After radiation therapy (30 Gy), the patient underwent a partial maxillectomy. Radiation therapy (20 Gy) was performed postoperatively.
No recurrence has been noted as of 2 years 6 month after surgery.

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Malignant fibrous histiocytoma (MFH) is a mesenchymal tumor rarely found in the maxilla, and its prognosis is very poor. We report a case of MFH arising in the right maxilla of a patient who has survived for a prolonged period after tumorectomy.
A 78-year-old man was referred to our department because of a mass in the right palatal region. Initial biopsy examination revealed a sarcoma; however, the histological type was unable to be determined. On immunohistochemical and transmission electron microscopic examination of a second biopsy specimen, a diagnosis of MFH was made. Continuous arterial infusion of 5 -FU and external irradiation with Co60-γ rays were given preoperatively. After chemotherapy and radiotherapy, the size of the tumor mass decreased. The tumor was excised with a partial maxillectomy. Thers is no clinical evidence of recurrence as of 8.5 years postoperatively.

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Extramedullary plasmacytomas rarely arise in the submandibular region. Here we report a case of extramedullary plasmacytoma occurring in the submandibular region and briefly review the literature.
A 93-year-old woman noticed a tumor arising in the right submandibular region. The tumor was exised and was suspected to be a plasmacytoma or multiple myeloma on pathological examination. Subsequent examinations ruled out the possibility of multiple myeloma.
On immunohistological examination, the excised specimen was identified to be an extramedullary plasmacytoma. At present, 2 years 9 months postoperatively, there are no signs of recurrence.

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We describe a 28-year-old man with a papillary cyst adenoma arising in the hard palate. The patient came to the hospital for further evaluation of a mass in the hard palate. MRI examination revealed a mass in the hard palate and signs of bone resorption. The mass was enucleated in a single mass under general anesthesia. The histopathological diagnosis was a papillary cyst adenoma. Forty-two months have passed since the operation, and the patient's progress has been good, without any signs of recurrence.

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Three cases of angiomyoma arising in the oral cavity are reported. The first case was in a 24-year-old man with a hemangiomatous swelling of the hard palate. The second case was in a 55-year-old woman with an elastic hard mass in the buccal mucosa. The third case was in a 64-year-old man with a slightly reddish swelling of the hard palate. The clinical diagnosis in the first case was hemangioma, whereas benign tumor was the clinical diagnosis in the two other cases. The tumors were completely excised under local anesthesia. Histological examination revealed well-demarcated nodular tumors consisting of smooth muscle-like tumor cells, which proliferated perivascularly in all cases. The histopathological diagnoses were angiomyoma.

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The combined effects of G-CSF (50 to 150μ g/one time) and erythropoietin (3, 000 IU/one time) on peripheral blood platelets were examined in 6 patients with oral and maxillary sinus carcinomas (2 were primary cases and 4 were secondary cases) who received concomitant chemoradiotherapy. In all patients who received both cytokines, blood platelets and white blood cells increased within a shorter period than in the control group.
The results indicate that combined treatment with G-CSF and erythropoietin is useful in the management of thrombocytopenia induced by cancer therapy.

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We report a case of a malignant tumor at the left side of the soft palate in a 47-year-old man who underwent immediate reconstruction using both a superiorly based pharyngeal flap and a palatal island flap. Velopharyngeal functions were studied with a nasopharyngeal fiberscope one month after operation. The velopharynx, divided into two orifices by the pharyngeal flap, showed complete closure on both deglutition and/p/production, but not on/a/production at the right orifice. One the surgical side, no space between the bulb of a obturator prosthesis and the pharyngeal walls was observed on either deglutition or/p/production, but a very small space was seen on/a/production. A proper amount of space around the obturator reflected the potential for muscular movement related to the production of speech. The defect of the soft palate was restored effectively with the prosthesis, with no loss of function. The usefulness of a pharyngeal flap for reconstruction of acquired lateral soft palate defects was discussed with respect to patients in whom residual velopharyngeal movement is expected.

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This paper describes a patient with a severely hypoplastic mandible that was corrected with a bilateral distraction procedure. The patient was an 8-year-old boy with Pierre-Robin syndrome who had received a bilateral costochondral graft 2 years ago to lengthen the mandible.
A corticotomy was performed in the mandibular body proximal to the previous bone grafts. With the use of external distraction devices, the mandible was maintained in fixation for 6 days to permit callus formation. The devices were then serially lengthened at 0.75mm per day, and the mandible was lengthened about 14 mm in total. After 8 weeks of consolidation, the external fixation was removed, and bony union was confirmed on X-ray examination.
This technique proved to be very useful for correcting the bilateral hypoplastic mandible.

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A 73-year-old man was referred to our hospital on December 3, 1993, because of secondary hemorrhage after extraction of the right mandibular molars. In 1990, a diagnosis of dissecting aortic aneurysm (DAA) was made and he had been receiving an anticoagulant until two months previously, when he stopped taking it for no particular reason.
Because local hemostatic procedures were only effective temporarily and because hematological examinations on variables, admission showed abnormal coagulation, we consulted the Third Department of Internal Medicine, Hokkaido University Medical Hospital. Coagulation tests at that department revealed low function of platelets, low values of VIII and XII factors, and high values of thrombin-antithrombin complex, plasmin-a plasmin inhibitor complex, and D-dimer. These findings fulfilled the diagnostic criteria for DIC established by the study group of the Ministry of Health and Welfare of Japan. Thus, a diagnosis of chronic DIC related to and DAA was made, because the patient's past history and family history were unremarkable, except for the DAA and a mild bleeding tendency. The local hemorrhage was well controlled after two days of oral treatment with tranexamic acid.

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A 49-year-old woman was referred to our department on April 18, 1990 for a continuous burning pain in her gingiva near the upper left molar. She complained that the pain had been provoked by endodontic therapy of her upper left second molar. The pain had persisted for the past three years despite medical treatment.
She had no clinical disorders other than pain. The characteristics of her pain and the patient's history of minor nerve injury caused by dental treatment led to a diagnosis of reflex sympathetic dystrophy (RSD).
Stellate ganglion block was effective. However, more than 200 procedures were required to eliminate all pain.

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It is difficult to identify foreign bodies by simple X-ray, CT, and MRI examination if the foreign body is radiolucent or resides in a deep region.
In this paper, we describe a patient with a foreign body (an ear of rice) in the left submandibular gland. Differentiation of the foreign body from simple inflammatory or tumorous lesions was difficult owing to the rare clinical characteristics of this case.

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