Michiaki Nakai

Immunohistochemical distribution of monoclonal antibodies against keratin in papillomas and carcinomas from oral and nasopharyngeal regions

Papillomas (40) and squamous cell carcinomas (75) were examined for the presence of three keratin proteins with the use of an immunohistochemical technique. Polyclonal keratin antibody (TK, detecting 41 to 65 kDa keratin) and monoclonal antibodies KL1 and PKK1 (55 to 57 kDa and 41 to 56 kDa, respectively) were used. Squamous epithelium in normal oral mucosa showed marked TK staining in cells of upper strata and relatively slight staining in basal layer cells, moderate KL1 staining in spinous and granular layers and was negative in basal cells. Positive PKK1 staining was noted in cells of the basal layer. Columnar epithelium in the nasal mucosa showed TK staining in all layers, KL1 staining on the apical side of epithelial cells and trace or negative staining in basal layer cells. There was moderate PKK1 staining along the apical side of cells and variable staining in basal cells. Keratin distribution in oral papillomas was similar to that in normal oral epithelium, whereas in nasal and nasopharyngeal papillomas, keratin distribution was restricted to the upper layers. Tonsillar papillomas showed a strong TK reaction, negative KL1 in upper layer cells, and marked PKK1 staining in basal cells. Well-keratinized squamous carcinomas indicated an irregular TK distribution and decreased KL1 and negative PKK1 stainings. Intermediate and poorly differentiated keratinizing squamous carcinoma showed irregular staining patterns for the three classes of keratins studied. Immunohistochemically detectable keratins utilizing monoclonal antibodies were described as useful markers of epithelial tumors of squamous origin. Keratin expression within benign tumors was related to normal regional distribution, whereas in malignant tumors, keratin distribution was irregular in its distribution profile.

Lectin-binding patterns in the developing tooth

SummaryThe lectin-binding patterns of the cells involved in amelogenesis and dentinogenesis in developing teeth of rats, were studied. Undifferentiated odontogenic epithelia exhibited very slight staining with almost all of the lectins examined. The lectin-staining affinities of secretory ameloblasts could be divided into two categories: Concanavalin-A (Con-A), Wheat germ agglutinin (WGA) and Soybean agglutinin (SBA) binding occurred from the middle to apical cytoplasm, whereas Ricinus communis agglutinin-I (RCA-I) and Ulex europeus I (UEA-I) binding predominated in the basal regions. The cells of the stratum intermedium exhibited relatively stranges lectin staining, which appeared to be dependent on ameloblastic maturation. The basement membranes in undifferentiated epithelia were markedly positive for lectin binding. Odontoblasts showed moderate Con-A staining on the apical side of the cells, as well as slight-to-moderate reactions with WGA and SBA. Pulp cells and dental papillae showed slight-to-moderate lectin staining, and predentin and dentin were also moderately positive for Con-A and RCA-I binding and slightly so for WGA and SBA. The lectin-binding affinities were enhanced during the formation of enamel and dentin, and appeared to be dependent on the degree of cellular differentiation in ameloblasts and odontoblasts.

Distribution of keratin proteins in neoplastic and tumorlike lesions of squamous epithelium

Seventy-six cases of tumorlike and neoplastic lesions from epidermis and oral epithelium were analyzed by a histochemical technique for the demonstration of keratin. Formalin-fixed paraffin sections were reacted with rabbit antihuman keratin antiserum (dilution of 1:40). The types of distribution of keratin in cells of lesions were classified into five categories: (1) regional, as found in normal squamous epithelia and benign hyperkeratinized lesions, and papilloma, and keratinized squamous cell carcinoma; (2) total, as seen in intensely keratinized lesions, such as verruca vulgaris and highly keratinized squamous cell carcinoma; (3) negative, as displayed by basal cell carcinoma; (4) scattered, as in the most poorly differentiated squamous cell carcinomas; and (5) mixed cellular, as found in both poorly and moderately differentiated squamous cell carcinomas.

Distribution profiles of keratin proteins during rat amelogenesis

SummaryWe examined rat cells undergoing amelogenesis for the presence of three types of keratin proteins using a polyclonal antibody to keratin (against total keratins (TK) with molecular masses ranging from 41 to 65 kilodaltons (kd) and monoclonal antibodies keratins to KL1 and PKK1 (reactive with keratins with molecular masses of 55–57 and 41–56 kd, respectively). In normal oral epithelia from young rats, the TK, KL1, and PKK1 antibodies bound to all of the epithelial strata. The epithelial cap on the top of incisors and the dental lamina of molar teeth exhibited strong TK staining, moderate staining KL1, and little or no PKK1 staining. In developing molar enamel organs, both the outer and inner enamel epithelia, the stratum intermedium, and stellate reticulum cells were all positively stained by the TK immunoreagent. In developing incisors, TK only bound strongly to stratum-intermedium cells, and no KL1 and PKK1 staining antibodies was observed in ameloblasts or the stratum intermedium.

A case of impacted first molar with chronic mandibular osteomyelitis

A case of a completely impacted first molar in the mandibular is described in a 44-year-old Japanese male. He complained of chronic inflammation of the mandible, and histopathological findings revealed osteomyelitis around the impacted tooth.