Lectin histochemistry of cystic jaw lesions: an aid for differential diagnosis between cystic ameloblastoma and odontogenic cysts.

The binding sites for Ulex europaeus agglutinin I (UEA-I), Bandeirea simplicifolia agglutinin I (BSA-I), and peanut agglutinin (PNA) were comparatively examined in the surgical materials from 41 cases of cystic and solid ameloblastomas and 42 cases of non-neoplastic odontogenic cysts including dentigerous cyst, odontogenic keratocyst, and radicular cyst. In non-neoplastic cysts, most of epithelial lining layers gave positive binding with UEA-I and BSA-I. However, no positive reactions were obtained for these two lectins in the epithelial components of ameloblastoma, except for limited UEA-I binding to markedly keratinized tumor cells in four cases. PNA binding was irregular and did not make any clear distinction between ameloblastomas and cysts. The results suggest that the lectin staining for UEA-I and BSA-I is a useful histologic aid for differential diagnosis between cystic ameloblastoma and non-neoplastic jaw cysts.

Immunolocalization of basement membrane molecules in the stroma of salivary gland pleomorphic adenoma.

In order to determine the participation of basement membrane molecules in formation of its characteristic stroma, 30 cases of salivary gland pleomorphic adenoma were examined by immunohistochemical staining for type IV collagen, laminin, heparan sulfate proteoglycan, and entactin. The stroma was histopathologically classified into four types: hyaline, fibrous, myxoid, and chondroid. Immunohistochemically, type IV collagen and laminin were more intensively localized in hyaline, fibrous and chondroid types of stroma, whereas heparan sulfate proteoglycan was more prominent in myxoid areas. The results suggest that the stroma contains these basement membrane components, which are possibly biosynthesized by epithelial tumor cells, and that histological variety of the stroma depends on proportion of local contents of each basement membrane molecule.

[Changes of muscle activities in neck and shoulder region during sustained isometric contractions of jaw muscles].

Eight healthy participants performed horizontal isometric jaw movements with maximum voluntary contractions of the jaw muscles until they could not tolerate the task. Electromyographic activities bilaterally recorded from the superior and inferior regions of the sternocleidomastoid muscle and the nuchal and shoulder regions of the trapezius muscle were observed. The results obtained were as follows: 1. In more than 94% of 32 trials, the amplitude of EMGs during the task were higher than those at rest, and in more than 79%, temporal changes in EMG burst were synchronized with the onset-offset of the exercise. 2. In more than 72% of all trials, small amplitude EMG lasted after cessation of the task. 3. Muscle activities of the lateral cervical region during the exercise were superior to the activity of the nuchal and shoulder regions, and amplitude of EMGs in the neck and shoulder regions tended to be the highest during isometric retrusion. 4. These results don't contradict with our hypotheses that occlusal habits might be one cause of the unpleasant sensation in the neck and shoulder regions and that sustained isometric retrusion might have heavier effects on it.