Immunohistological examination of guinea pig cochleas was performed using a panel of 25 monoclonal antibodies directed to various lacto-, ganglio- and globo-series carbohydrate epitopes as well as mucin-type epitopes. Lacto-series structures were found to be localized at specific sites of the tectorial membrane (TM) and Corti's organ, i.e. alpha 1-->3 fucosyl type 2 chain (Le(x)) at Kimura's membrane, marginal band and covering net of TM; alpha 1-->2, alpha 1-->3 difucosyl type 2 chain (Le(y)) at covering net; and sialosyl-Le(x) and sialosyl-i at Kimura's membrane and sensory epithelia, particularly sensory tips of hair cells of Corti's organ. In striking contrast, ganglio-series structures (GM3, GD3, GD2, 9-O-Ac-GD3) were detected at spiral ganglion cells, neuronal fibres and stria vascularis, but were completely absent from Corti's organ and most of the TM. Other epitope structures defined by various antibodies were not detectable at any location. The functional roles of lacto-series carbohydrate epitopes expressed at TM and Corti's organ remain unknown. However, the expression of Le(y) (but not other structures) in association with developmental deficiency of TM induced by 6-N-propyl-2-thiouracil in rats suggests that Le(y) plays some role in normal TM development. The presence of Le(x) at Kimura's membrane and sialosyl-Le(x) at hair cell sensory tips of Corti's organ suggests the intriguing possibility that these fucosylated/sialosylated carbohydrate structures play some role in interactions (either attractive or repulsive) of these inner ear components, which have been implicated in the physiology of hearing, i.e. the conversion of sound waves to nerve impulses.
NGFR-immunoreactivity was first detected in the epithelia of the otic placode at E 10 and the entire epithelium of the otic vesicles was NGFR-immunoreactive at E 11. At this stage no nerve fibers were present in the epithelia and the immunoreactivity was confined to portions of the otic epithelium where the immunoreactive nerve bundles penetrated. As the development proceeded and the organ of Corti was matured, NGFR-immunoreactivity was localized on the plasma membrane of intraepithelial nerve fibers, that of adjacent epithelial cells apposed to the nerve fibers, and apical microvillous membrane of the supporting cells directly apposed to the hair cells. The occurrence of NGFR-immunoreactivity in the otic epithelial cells from early stages of development suggests that NGFR in the epithelia might provide a means to concentrate NGF on the cells which would become the substratum for growing nerve fibers in development. Furthermore, the specific appearance of NGFR-immunoreactivity in the apical microvillous membrane of the maturing supporting cells implies that NGF secreted into the endolymph from somewhere in the otic epithelia may exert some, yet to be defined effects on the supporting cells in the maturation of the organ of Corti.
This paper reported both ultrastructural and biochemical studies of nasal polyps from 32 patients: 5 with an aspirin-induced asthma; 14 allergic patients with rhinitis; and 13 nonallergic patients with negative skin tests against the major inhalant allergens. The results of the studies have clearly shown that there are two different types of nasal polyps, neutrophil-dominant polyps and eosinophil-dominant polyps, and both leukocytes play a major role as important effector cells in the formation of nasal polyps. Cytotoxic effector molecules from both leukocytes initiate the connective tissue damage of the capillary basement membrane, bringing about enormous tissue edema, with broad disruptions of the epithelial lamina, causing polyp formation.
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