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Expression of retinoblastoma (Rb) protein was immunohistochemically examined in laryngeal squamous cell neoplasias from 72 patients. Staining patterns were considered with reference to such prognostic factors as patient's age, histologic grade, tumour size and lymph node status, and 5-year survival rate. Rb protein negativity, either partial or complete, was noted in 28.8% of cases and was associated with a significantly lower 5-year survival rate, as well as with a higher likelihood of lymph node metastasis. This suggests that Rb alteration may be a prognostic indicator in patients with laryngeal carcinoma.

Glyconjugate expression in formalin-fixed, paraffin-embedded Sjögren's syndrome labial glands (nine cases) was compared with that in normal glands (12 samples) using a wide panel of lectins. Mucous cells expressed mainly mucous-type glycoproteins including sialyl, fucosyl, galactosyl and galactosaminosyl residues, and some N-linked glycoconjugates. Demilunar cells expressed mainly alpha D-mannose, GlcNAc and Gal beta 1.3-GalNAc. Duct cells and cellular glycocalyx expressed O-linked and N-linked residues. Sjögren's syndrome samples showed a statistically significant increase in the expression of GlcNAc. A significantly decreased expression of Gal beta 1,3-GalNAc and alpha D-mannose, residues not usually present in mucous cells, was found (p0.05). This suggests that anatomic rather than functional alterations determine mucous cell impairment and the symptoms in Sjögren's syndrome.

Sialoglycoconjugates in the developing murine tubotympanum were characterized using lectin histochemistry with wheat germ agglutinin (WGA), Limax flavus agglutinin (LFA), Sambucus nigra agglutinin (SNA), Maackia amurensis agglutinin (MAA), peanut agglutinin (PNA), and neuraminidase treatment. WGA, LFA, MAA, and neuraminidase-PNA labeled epithelial goblet cells, glandular mucous cells, and cell surfaces of adult and newborn murine tubotympanum. SNA did not label any secretory components. PNA labeled secretory cells and cell surfaces of the fetal tubotympanum without neuraminidase treatment. After birth, these secretory cells and cell surfaces were labeled with PNA only after neuraminidase treatment. These results revealed that: Sialoglycoconjugates are produced from glandular mucous cells and epithelial goblet cells and are present on cell surfaces and within the mucous blanket; their terminal tri-saccharide linkage appears to be the sequence Neu5Ac(alpha 2-3)Gal(beta 1-3)GalNAc; sialic acids appear before birth and gradually increase; terminal galactose residues are masked by sialic acids after birth.

Ueno K, Wang ZH, Hanamure Y, Yoshitsugu M, Fukuda K, Furuta S, Uehara F, Ohyama M. Reduced sialylation of glycoproteins in nasal glands of patients with chronic sinusitis. Acta Otolaryngol (Stockh) 1997; 117: 420-423.This study was conducted to investigate the sialylations of glycoproteins in the nasal glands of patients with chronic sinusitis. Sialic acids were detected using lectin histochemistry, and the mRNA of sialyltransferase was evaluated by in situ hybridization histochemistry. Sambucus nigra agglutinin (SNA), which recognizes terminal sialic acids, strongly stained the glandular mucous cells of normal subjects, but not those of patients with chronic sinusitis. In situ hybridization histochemistry showed that the expression of α2,6 sialyltransferase mRNA was decreased in the secretory cells of patients with chronic sinusitis. Our present results suggest that a reduction in sialyltransferase activity at the mRNA level in the nasal glands may lead to the persistence of chronic sinusitis.