Polymyxin B binding sites in Escherichia coli as revealed by polymyxin B-gold labeling

A complex of polymyxin B, bovine serum albumin, and colloidal gold was prepared and used for the ultrastructural localization of polymyxin B binding sites on thin sections of Epon-embedded Escherichia coli cells. Gold particles were found on the outer membrane of E. coli, which is consistent with reported biochemical findings. We concluded that gold labeling with polymyxin B is useful in localizing the binding sites of polymyxin.

Cytochemical localization of specific carbohydrates in the cochlea using wheat germ agglutinin-gold

Localization of specific carbohydrates in the cochlea was examined by postembedding labelling by wheat germ agglutinin (WGA)-gold at the electron microscopic level. Gold labelling was observed in the tectorial membrane, basilar membrane, basal membrane of the capillary and other connective tissues. In these areas, the labelling was observed over either fibrous structures or the ground substance. WGA is known to bind specifically with N-acetylneuraminic acid, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and its beta-(1-4)-linked oligosaccharides. The labelled sites, therefore, are considered to indicate the presence of glycoconjugates that contain these carbohydrates as their constituent.

Wheat germ agglutinin binding sites in the organ of Corti as revealed by lectin-gold labeling

The distribution of wheat germ agglutinin(WGA)-binding sites in the organ of Corti of the guinea pig and mongolian gerbil was studied. WGA was conjugated with gold particles and applied on thin sections of the cochlea embedded in Spurr's resin and in Lowicryl K4M. WGA-binding sites were found on the plasma membrane, lysosomes and cytoskeletons of hair and supporting cells as well as on the tectorial and basilar membranes. No distinct difference was discovered between hair cells and supporting cells in terms of WGA-binding activities.

Amylase secretion by nasal glands. An immunocytochemical study

Amylase, an enzyme that hydrolyzes starch, has been localized in the nasal mucosa for the first time by the protein A-gold technique. The amylase appeared to be produced by serous cells of the nasal glands. This enzyme has the potential for use as a tumor marker for cancer of the nasal cavity. The function of amylase in the physiology of nasal secretions is discussed.

Lysozyme producers in nasal mucosa. An immunocytochemical study

The question of whether or not goblet cells in the nasal mucosa are lysozyme producers has yet to be examined. In the present study, lysozyme was localized by the protein A-gold technique in human nasal mucosa with special attention to goblet cells. Both light and electron microscopic immunostaining revealed lysozyme in the secretory granules of the goblet cells, although far less than the amount present in the serous cells of the nasal glands. We concluded that the nasal glands were the main producer and goblet cells the subsidiary producer of lysozyme in nasal mucosa.

Aminoglycoside binding sites in the cochlea as revealed by neomycin-gold labelling

Neomycin/bovine serum albumin/gold was used as a probe to detect the binding sites of aminoglycosides on the thin sections of the cochlea embedded in Spurr. The binding sites were mainly located on the stereocilia, the cuticular plate of hair cells, the head plates of Deiters' cells, fibrous structures in pillar cells, in the spiral limbus and tectorial membrane and basilar membrane, plasma membranes, mitochondria and the chromatin of various kinds of cells. Triphosphoinositide, acidic glycosaminoglycans, and RNA were considered to be responsible for the binding activity.

Polymyxin-B-binding sites in the cochlea as demonstrated by polymyxin-B/gold labeling

A polymyxin-B/bovine-serum-albumin/gold complex was used as a probe to detect the binding sites of polymyxin B on thin sections of cochlea embedded in Spurr's resin. The binding sites were found to be mainly located on the stereocilia, the cuticular plate of hair cells, the head plate of Deiters' cells, the tonofilaments in pillar cells and Deiters' cells, fibrous structures in the spiral limbus, the tectorial membrane and the basilar membrane and neural elements such as nerve endings, fibers, and the myelin sheath. The mitochondria, plasma membrane, and chromatin of the nuclei of the cells observed also exhibited binding. Our results suggest that phospholipids, glycoconjugates, cytoskeletal proteins and nucleic acids are responsible for this binding activity.

Bacteriolytic activity of lysozyme in the nasal mucosa

During an experiment to study the localization of the lysozyme in the nasal mucosa of humans by the protein A-gold technique, we observed the accumulation of lysozymes around bacteria possibly causing bacteriolysis. The lysozyme, therefore, seems to play a preventive role against some kind of bacterial infection in the nasal mucosa in situ.

Binding sites of an aminoglycoside in the cochlea examined by immunocytochemistry

To localize the binding sites of aminoglycosides in the cochlea, immunocytochemistry was used with the antibody to gentamicin and the protein-A/gold complex. We found that the main binding sites were the stereocilia, the cuticular plates of hair cells, the head plates of Deiters' cells, cell filaments and the cones of pillar cells, tectorial membranes, basilar membranes, the matrix of the spiral limbus, plasma membranes, mitochondria, and the chromatin of various kinds of cells. Triphosphoinositide and acidic glycosaminoglycans are the two most likely candidates for the cause of binding activity.

Experimental immune complex otitis media: localization of IgG by protein A-gold technique

Immune complex (IC) was made of bovine serum albumin (BSA) and anti-BSA guinea pig serum, and instilled into the tubotympanic cavity of untreated guinea pigs. The location of IgG was determined by using the protein A-gold technique to trace IC in the tubotympanic mucosa of the otitis media with effusion (OME) caused by the instillation. IgG was found on the effusion, degenerated ciliated cells and on granules of goblet cells. There was no evidence of intense accumulation of IgG on the basement membrane of the mucosal epithelium or the capillaries. It is likely that IC activates complements in the tubotympanic cavity to cause OME.

Localization of lysozyme in the frozen section of nasal mucosa by protein A-gold technique

The location of lysozyme was studied in frozen sections of the nasal gland by protein A-gold technique, modified for the frozen section. Serous glands were enriched with lysozyme. Within the glands, the apical portion of the serous cells was most heavily stained. The epithelial layer was virtually unstained for lysozyme. The result was essentially the same as that obtained by the peroxidase-antiperoxidase method. Electronmicroscopic examination of the stained sections supports the possible application of this method for pre-embedding immunostaining, although further improvement of the technique is necessary.

Studies of the substructures of the lysozyme-rich secretory granule of the serous cell in the human nasal gland

Using a protein A-gold immunohistochemical technique, the lysozyme rich core and the lysozyme free peripheral rim were differentiated in the secretory granule of the serous cell in the human nasal mucosa, under the electronmicroscope. The shperical lysozyme rich core, which had been excreted into the gland lumen, was also wrapped with the peripheral rim. This finding suggests that the peripheral rim defends the integrity of the core and inhibits the release of lysozyme from the core.

The site of involvement of hypertension within the cochlea. A comparative study of normotensive and spontaneously hypertensive rats

The function and morphology of the cochlea of the spontaneously hypertensive rat (SHR) were examined and compared with the age-paired normotensive Wistar Kyoto rat (WKY). Electro- cochleographic study revealed that the function of the cochlea in the SHR declined with increasing age to a greater extent than that of WKY. Electronmicroscopic study revealed that the primary site of the cochlear deterioration of the SHR was the vascular stria, followed by the organ of Corti. Some hypotheses to explain this phenomenon are proposed for further study.

Freeze-replica observations of guinea pig middle ear muscles

The histological characteristics of the middle ear muscles, Musculus tensor tympani and M. Stapedius, of the guinea pig were studied using freeze-fracturing technique. No gap junction was observed but the tight junction was found in the tensor tympani muscle, possibly between muscle cells. No distinct difference was found between the size distributions of the apertures and caveolae on the fracture face of the sarcolemma of the two kinds of muscles.

Localization of triphosphoinositide in the cochlea. An electronmicroscopic immunocytochemical study

Triphosphoinositide (TPI) has been demonstrated to be a receptor for aminoglycosides in the cochlea and may regulate ionic permeability by its binding with Ca++. This phospholipid was localized by a protein A-gold technique in the cochlea at the electronmicroscopic level. TPI was prepared by a neomycin column and antibodies to it were raised in rabbits. The antibody used in this study reacted virtually only to TPI among the tested lipids. TPI was localized mainly at stereocilia, cuticular plates, head plates of Deiters' cells, plasma membrane, and mitochondria of various cells in the organ of Corti. In the vascular stria, TPI was found mainly at the plasma membrane of basal infoldings of the marginal cells. Possible physiological and pathophysiological roles of TPI in the cochlea are briefly discussed.

Establishment and characterization of a carcinoembryonic antigen producing cell line derived from human pancreatic exocrine cancer

A human pancreatic carcinoma cell line derived from well differentiated tubular adenocarcinoma of the pancreas head has been established and maintained for nearly 4 years. This established cell line produces and releases carcinoembryonic antigen into the culture medium. The cell line grows as a monolayer in RPMI-1640 medium containing 10 percent fetal calf serum. Xenotransplantation in athymic nude mice after subcutaneous injection of EDTA-trypsin treated cells did not succeed.

Fine morphology of the secretory mode of the tetragastrin-stimulated chief cells of human and dog gastric mucosa

The chief cells of the gastrin-stimulated gastric mucosa of human and dog were observed under a light and electron microscope. Four microgram/kg AOC-tetragastrin were given parenterally by a single shot to a man and three dogs respectively. Pepsinogen in the gastric mucosa increased at the wash-out stage and at the following dynamic equibrium stage of the chief cell secretion cycle after the administration of AOC-tetragastrin. During those stages, the chief cells released zymogen granules intensively. As the main ultrastructural process for releasing the zymogen granules, the emiocytosis in man and the apical cytoplasm dissociation in dog were discussed.

On the periodically aggregated particles on the fracture face of the cochlear hair cell

By means of the freeze-fracture technique, the membrane specialization of the cochlear hair cell of guinea pigs was studied. Periodically aggregated particles were revealed on the PF face of the plasma membrane of the outer hair cell. The particles were around 12 nm in diameter and 10 to 17 nm in center-to-center spacing. Their arragement was hexagonal, orthogonal or parallel. Possible involvement of this structure in the electrical excitability of the membrane was discussed.

Membrane unbound crystals in pancreatic acinar cells of the mouse

The exocrine pancreas of normal mice was investigated electron microscopically. The crystals were encountered in the basal cytoplasm of the acinar cells. They exhibited usually rectangular or rhomboidal profiles, measuring less than 5 mum in length and more than 0.1 mum in width. The matrices of these crystals displayed substructures of parallel dense linear pattern. The center-to-center distances between the dense lines were 100 similar to 150 A. The crystals were not limited at their surface by any membrane, but rather were densely circumscribed or sporadically surrounded by ribosomes. Filaments were interposed between ribosomes and crystal matrices and also between matrices of abutting crystals. The significance of the close relation of ribosomes to crystals was discussed.