Sukehide Yamashita

Inhibition of Na+, K+ ‐ATPase Activity by Phospholipase A2 and Several Lysophospholipids: Possible Role of Phospholipase A2 in Noradrenaline Release from Cerebral Cortical Synaptosomes

Abstract— p‐Bromophenacyl bromide (PBPB), quinacrine and indomethacin, which inhibit phospholipase A2 (PLA2; EC 3.1.1.4) activity in several tissues, caused a dose‐dependent inhibition of prelabelled [3H]noradrenaline ([3H]NA) release evoked by high concentrations of K+ from rat cerebral cortical synaptosomes. Release of prelabelled [3H]NA was caused by natural lysophosphatidic acid (LPA; 10−6‐10−5 gmL−1) and lysophosphatidylcholine (LPC; 10−6‐10−5 g mL−1) and synthetic LPA (6 × 10−6, 2 × 10−5 M) and LPC (6 × 10−6, 2 × 10−5 M), but not by natural lysophosphatidylserine (LPS; 10−5 g mL−1), lysophosphatidylethanolamine (LPE; 10−5 g mL−1) and lysophosphatidylinositol (LPI; 10−5 g mL−1). The release evoked by natural LPA and LPC could be inhibited only marginally by PBPB and quinacrine. Phosphatidic acid (PA)‐specific and phosphatidylcholine (PC)‐specific PLA2 activities from rat cerebral cortical synaptosomes were stimulated in incubation medium containing high concentrations of K+ or calcium ionophore A23187. Low concentrations of PLA2 (10−6–10−8 g mL−1, from bee venom) inhibited the synaptic membrane Na+, K+‐ATPase activity in incubation media with intracellular levels of free Ca2+. Several lysophospholipids (LPLs), metabolites of the PLA2 type, also inhibited the synaptic membrane Na+, K+‐ATPase activity in a dose‐dependent manner. The minimum effective concentrations of natural LPA, LPC, LPS, LPI and LPE were 10−6, 4·7 × 10−6, 10−5,4·7 × 10−5 and 4·7 × 10−5 g mL−1, respectively. These results suggest that PLA2 and/or its metabolites, LPLs, especially LPA and LPC, may play partial roles in the depolarization and/or release of noradrenaline through their inhibitory action on the Na+, K+‐ATPase activity in the brain.

Chondroma and osteochondroma of the tongue

The first case of two separate tumors of the tongue, one cartilaginous and the other osteocartilaginous, is reported. The cartilaginous matrix of these two tumors contained elastic fibers and type II collagen. The histogenesis of these tumors is discussed.

Heterotopic central neural tissue of the tongue

A rare case is reported of a pedunculated tumor containing heterotopic central neural tissue in the tongue of a 3-month-old girl. The lesion was located near the foramen caecum and was composed of glial cells, ependymal cells, a small number of neuronal cells and a relatively thick peripheral nerve.

Eosinophilic Granuloma Showing Rapid Regression: Report of a Mandibular Case with Application of a Modified PNA Staining Method for Demonstration of Langerhans‐type Histiocytes

A mandibular eosinophilic granuloma in a 16‐year‐old male is reported. This case showed rapid regression, which was clearly demonstrated by histopathological examinations of both preoperative biopsy and surgical materials. Transformation from an eosinophilic granuloma to a xanthomatous granuloma with multinucleated giant cells was observed after only 26 days. Special staining of paraffin sections with peanut agglutinin (PNA) and use of electron microscopy showed that the main component of the lesion in the biopsy material was Langerhans‐type histiocytes. These cells had disappeared from the lesion by the time of the operation. At the same time, the number of infiltrating eosinophils was also markedly reduced. It seems appropriate to consider that the rapid regression of this disease was correlated with the rapid reduction in the number of Langerhans type histiocytes appearing in the granulomatous foci, as well as the number of infiltrating eosinophils.

Bone scintigraphy and pathological basis of the mucoepidermoid tumor of the mandible: Report of a case

Bone scintigraphy with 99m-Tc HMDP was investigated for its pathological basis in a patient with mucoepidermoid carcinoma in the right molar region of the mandible. An accumulation of 99m-Tc HMDP was remarkable in the bone surrounding the tumor. There were large numbers of osteoblasts and a large increase in the amount of osteoid tissue which lined most of the surface of the immature woven bone. The result of our investigation suggested that the concentration of 99m-Tc HMDP was not tumor specific in itself and mostly depend on production of reactive immature new bone. The bone scintigraphic finding was necessary to be interpreted according to the pathological basis.

MR imaging of tumor-like swelling in the submandibular region

Tumor-like swellings in the submandibular region were evaluated in seven patients with MR imaging. Two cases of pleomorphic adenoma and two of sialoadenitis were selected as examples of submandibular gland lesions, while a plunging ranula, dermoid cyst and lymphadenitis were selected as examples of extraglandular lesions. The pleomorphic adenoma was connected with the remaining gland on T1-weighted images. The sialoadenitis showed changes in the size, signal intensity and homogeneity of the submandibular gland itself. On the other hand, extragland lesions showed zonal interpositions between the lesion and the submandibular gland, which showed either low or high signal intensity on T1-weighted images. On T1-weighted images, the intensity of all of the lesions was either lower than or the same as the normal submandibular gland. On the other hand, all lesions showed higher signal intensity, ranging from slight to very high on T2-weighted images. Sharp margins were seen in all lesions except one sialoadenitis. The sialoadenitis showed inflammatory infiltration into the surrounding tissue. A homogeneous internal pattern was observed in the case of cystic lesions, while an inhomogeneous internal pattern was noted in the pleomorphic adenoma and in the inflammatory lesions. Gd-DTPA enhanced the T1-weighted images in three cases. Pleomorphic adenoma and lymphadenitis were enhanced inhomogeneously, whereas the ranula was not enhanced.

Scanning electron microscopic study of odontogenic keratocysts

Three odontogenic keratocysts were examined with a scanning electron microscope (SEM) on their surface cells, prickle cells, basal cells, and the epithelial-connective tissue interface. The microridges of the surface cells had a short, discontinuous, branched or beaded appearance. Intracellularly, the flattened keratinized cells formed a network consisting of delicate microfilaments. The prickle cells had numerous cytoplasmic projections and a large round nucleus that occupied most of the cytoplasm. The basal cells had two types of cytoplasmic process and a large oval polarized nucleus. The epithelium and the lamina propria were connected by a fibrous and fibrillar network.

Clinico-statistical observation of malignant tumors in our clinic. Report on 285 cases over the past 15 years.

1976年1月から1990年12月までの15年間に, 鹿児島大学医学部歯科口腔外科および鹿児島大学歯学部第1口腔外科において, 治療を行った悪性腫瘍患者285例を対象として臨床統計的観察を行い, 以下の結果を得た。1.対象症例285例中, 癌腫は267例 (93.7％) , 肉腫は16例 (5.6％) , その他は2例 (0.7％) であり, また, 性別は男性173例, 女性112例で, 男女比は1.5: 1であった。初診時年齢は21～92歳, 平均59.8歳, 年齢分布では60歳台 (30.9％) が最も多かった。2.癌腫267例の初発症状としては, 疼痛 (29.6％) , 腫瘤 (27.9％) , びらん・潰瘍形成 (20.0％) が多く, 一方, 一次症例271例の発生部位では, 舌が103例 (38.0％) と圧倒的に多かった。3.組織型別では, 扁平上皮癌が234例に達し, 全体の82.1％, 癌腫の87.6％を占めていた。4.治療法としては, 術前化学療法後に手術を行ったものが87例 (30.5％) , 手術単独が85例 (29.8％) などであった。5.一次症例271例の5年累積生存率は66.3％, 組織型別では, 癌腫は67.1％, 肉腫は45％, その他の悪性腫瘍は100％であった。

Eosinophilic granuloma of the ramus similar to malignant neoplasm or osteomyelitis: Report of a case

An eosinophilic granuloma was discovered in the region of the ramus of the mandible. This case occured in a very rare location limited only to the ramus, and showed similar features resembling osteomyelitis or malignant neoplasm at different stages of the disease. The radiographic findings indicated a diagnosis of malignant neoplasm and the scintigraphic manifestations showed that of osteomyelitis. The histopathological examinations showed different manifestations in accordance with the respective stages of the disease. This case was finally diagnosed as eosinophilic granuloma showing rapid regression.

Pemphigus vulgaris. Report of a case with electron microscopic observations of the lesion.

Pemphigus vulgaris is a chronic autoimmune bullous disease with a severe prognosis which involves the epidermis and mucous membranes.A 24-year-old woman was referred to our clinic for diagnosis and treatment of bullae and erosion of oral mucosa.Intraoral examination revealed numerous extensive erytheraatous erosion on the palate, tongue, buccal mucosa, and labial mucosa.Specimen for biopsy was obtained from lower lip mucosa.Histopathological features showed suprabasal intraepithelial bulla formation with acantholysis typical of pemphigus vulgaris.Direct immunofluorescent staining demonstrated intercellular substance deposition of IgG.Ultrastructural investigation in oral pemphigus vulgaris showed loss of desmosomes, widened intercellular spaces and the tonofilaments accumulated around the nucleus.The diagnosis of pemphigus vulgaris was established, and treatment with 40mg prednisone daily was instituted. With progressive improvement the dosage was tapered.The skin and oral lesions remitted and a maintenance dose of 5mg of prednisone every other day and 25mg of gold sodium thiomalate once a week was instituted.