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Biomedical subjects

M Sakagami

Publications and source records attributed to M Sakagami.

At least 91 records · Page 5Linked to original sources
PubMed1993

Saponin and sapogenol. XLVIII. On the constituents of the roots of Glycyrrhiza uralensis Fischer from northeastern China. (2). Licorice-saponins D3, E2, F3, G2, H2, J2, and K2.

Following the characterization of licorice-saponins A3 (2), B2 (3), and C2 (4), the chemical structures of licorice-saponins D3 (5), E2 (6), F3 (7), G2 (8), H2 (9), J2 (10), and K2 (11), seven of the ten oleanane-type triterpene oligoglycosides isolated from the air-dried roots of Glycyrrhiza uralensis Fischer collected in the northeastern part of China, were investigated. On the basis of chemical and physicochemical evidence, the structures of licorice-saponins D3, E2, F3, G2, H2, J2, and K2 have been determined to be expressed as 3 beta-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucuronopyranosyl(1-- >2)-beta-D-glucuronopyranosyloxy]-22 beta-acetoxyolean-12-en-30-oic acid (5), 3-O-[beta-D-glucuronopyranosyl(1-->2)-beta-D- glucuronopyranosyl]glabrolide (6), 3-O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucuronopyranosyl(1--> 2)-beta-D-glucuronopyranosyl]-11-deoxoglabrolide (7), 24-hydroxyglycyrrhizin (8), 3-O-[beta-D-glucuronopyranosyl(1-->2)-beta- D-glucuronopyranosyl]liquiritic acid (9), 24-hydroxy-11-deoxoglycyrrhizin (10), and 3 beta-[beta-D- glucuronopyranosyl(1-->2)-beta-D-glucuronopyranosyloxy]-24-+ ++hydroxyoleana- 11,13(18)-dien-30-oic acid (11), respectively.

China↗
PubMed1993

Saponin and sapogenol. XLIX. On the constituents of the roots of Glycyrrhiza inflata Batalin from Xinjiang, China. Characterization of two sweet oleanane-type triterpene oligoglycosides, apioglycyrrhizin and araboglycyrrhizin.

Two sweet oleanane-type triterpene oligoglycosides named apioglycyrrhizin and araboglycyrrhizin were isolated from the air-dried roots of Glycyrrhiza inflata Batalin, collected in Xinjiang province (Shinkyo-Kanzo in Japanese), together with glycyrrhizin (3), licorice-saponins A3 (8), G2 (10), and H2 (11) and known flavonoid glycosides. On the basis of chemical and physicochemical evidence, the structures of apioglycyrrhizin and araboglycyrrhizin have been determined to be expressed as 3-O-[beta-D-apiofuranosyl(1-->2)-beta-D- glucuronopyranosyl]glycyrrhetic acid (1) and 3-O-[alpha-L- arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]glycyrrhet ic acid (2), respectively. During the course of these studies, it has been found that the hydroxyl groups in the oligosaccharide moiety of the glucuronide saponins may be partially methylated by prolonged treatment with diazomethane in methanol. The sweetness of the saponins hitherto isolated from various Glycyrrhizae Radix has been examined and a structure-sweetness relationship, as compared with glycyrrhizin, has been found.

China↗
PubMed1993

The role of summating potential in the diagnosis and management of Menière's disease.

To assess the role of a negative summating potential (-SP) in the clinical diagnosis and management of Menière's disease, the relationship of -SP abnormality to clinical symptoms, hearing level and caloric test results was examined in 70 patients with unilateral Meniere's disease. The click-induced -SP and action potential (AP) were recorded by extratympanic electrocochleography. When SP/AP ratio exceeded 0.43, the -SP was considered to be abnormal. No significant relationship was found between abnormal -SP and clinical symptoms (the duration of cochlear and vestibular symptoms, recent hearing fluctuation and recent vertigo attack). Ears with abnormal -SP had a significantly worse hearing loss at high frequencies (2-8 kHz) than ears with normal -SP, whereas there was no significant difference in hearing loss at low frequencies (0.25-1 kHz) between both ears. No significant relation was found between abnormal -SP and abnormal unilateral weakness in caloric test. The results indicate that the click-induced -SP reflects the pathophysiology of Menière's disease basically in the cochlear partition at high frequencies.

Action Potentials↗
PubMed1993

Morphological aspects of transport of potassium ion in the marginal cell.

Structure and function of the marginal cell in the stria vascularis were studied by freeze-fracture, cytochemistry and immunohistochemistry with special regard to the ion transport of potassium. Freeze-fracture showed that marginal cells were connected by tight junctions beneath the scala media K(+)-NPPase cytochemistry showed that Na+, K(+)-ATPase was abundant on the basolateral infoldings of the marginal cell. Immunohistochemistry of a rat Isk protein, which has a property of a potassium channel, revealed that the rat Isk protein was localized at the endolymphatic surface of the marginal cell. These findings supported the 'one-pump' theory (Offner et al. Hear Res 1987; 29: 117-24).

Animals↗
PubMed1993

The ultrastructure of the basilar papilla of the budgerigar's inner ear.

The basilar papilla in the inner ear of the adult budgerigar was studied by scanning and transmission electron microscopy. The sickle-shaped basilar papilla has short hair bundles on the proximal tip and long ones on the distal tip. The tectorial membrane shows a honeycomb-like pattern and enclosed a hair bundle in its alveolus. The papilla consists of two different types of hair cells; short and tall hair cells. The short hair cells with large efferent nerve endings are located on the free basilar membrane in the inferior part. The tall hair cells with large afferent nerve endings are located in the superior part. The similarity and difference of the structure are discussed between the budgerigar and other birds, and between birds and mammals.

Animals↗
PubMed1993

Electron microscopical observations of melanin in the endolymphatic sac.

Endolymphatic sacs of pigmented guinea pigs were examined by light and electron microscopy. Melanocytes were located not only in the subepithelial connective tissue but also in the intercellular spaces between the epithelial cells. They projected their dendrites into the epithelium extensively. Melanosomes in several stages of maturation and well-developed Golgi apparatus were seen in the cytoplasm of the melanocytes. Melanosomes were also observed in the membrane-bound vacuoles of the epithelial cells. These findings suggest that melanocytes in the endolymphatic sac are highly capable of producing tyrosinase, synthesizing melanin and transferring melanosomes to the epithelial cells, while melanocytes in the other parts of the inner ear do not show signs of melanogenesis under normal conditions.

Actin Cytoskeleton↗
PubMed1993

Measurement of anaphylatoxin activity during surgery.

We studied whether or not anaphylatoxins (ATs) are related to stress-related surgery by examining AT measurement in 51 patients undergoing operation. C3a plasma levels in patients who underwent the Caldwell-Luc operation increased from a pre-surgery concentration of 129 +/- 19 (mean +/- SD) ng/ml to 293 +/- 91 ng/ml during surgery under local anesthesia. However, pre- and post-surgery values were almost the same. No significant change occurred in the C5a plasma concentration at any time in patients undergoing the Caldwell-Luc operation, tonsillectomy or partial glossectomy. The mechanism underlying elevation in C3a during surgery is discussed.

Adult↗
PubMed1993

Pathological specimens of rat temporal bone--comparison between different fixative solution.

We investigated the difference in temporal bone specimens fixated by three sorts of fixative solution (10% formalin fixative, Wittmaack's fixative and Heidenhein-SuSa fixative). 1. 10% Formalin's fixative solution We found many pinkish precipitates, which are stained by hematoxy-eosin, in the scala media of the cochlea. Same substance is found in the perilymphatic space and endolymphatic space in the vestibulum. The fusion of the cells is indicated in the tectorial membrane, inner sulucus cell, outer sulucus cell especially in the apical turn of the cochlea. 2. Wittmaack's fixative solution The detachment of inner and outer sulucus cells are found from basilar membrane at the basal turn of the cochlea. The tendency in convex and concave form of the Reissner's membrane is most remarkable in these three fixative solution. 3. Heidenhein-SuSa fixative solution In this solution, no precipitates, no fusion of cells are found. No detachment of the inner or outer sulucus cells is also found. This study indicates that Heidenhein-SuSa fixation is most excellent fixative method.

Animals↗
PubMed1993

Immunological pathogenesis of endolymphatic hydrops and its relation to Menière's disease.

This study was designed to investigate an immunologically induced endolymphatic hydrops (ELH) and to focus on the issue of its pathogenesis in relation to Menière's disease. The time course of ELH was evaluated by light microscopy in a 2-hour to 7-month period following direct antigen challenge to the endolymphatic sac (ELS) in systemically pre-sensitized guinea pigs. ELH began to appear in the vestibule and the basal turn 5-7 hours after inner ear challenge and developed gradually. During the interval from the second day to the first week, ELH rapidly developed in all the cochlear turns and reached a maximum size. During the period from the second week to the eighth week, ELH gradually reduced. After 9 weeks, ELH of the saccule and the cochlea gradually recurred. During the interval from the first week to the eighth week, the time course of ELH correlated well with the grade of cellular infiltration of the perisaccular tissue. These results suggest that recurrent immunological reaction in the ELS may result in disorders of the ELS which finally lead to the onset of Menière's disease.

Animals↗
PubMed1992

Absorption of horseradish peroxidase in the endolymphatic sac: ultrastructural cytochemistry using a new electrophoretic technique.

Using a newly developed injection technique, the absorption of horseradish peroxidase (HRP) in the endolymphatic sac (ES) of the guinea pig was examined by light and electron microscopy. HRP (molecular weight: 40,000; molecular diameter: about 5-nm) was directly injected into the lumen of the ES by electrophoresis after the recording of a direct current potential in the ES lumen. Both the macrophages floating in the ES lumen and the epithelial cells in the intermediate portion of the ES absorbed intraluminal HRP. The macrophages internalized the intraluminal HRP at a higher rate than the epithelial cells, suggesting that macrophages play a major role in macromolecular absorption in the ES. It was considered that the macrophages took up intraluminal HRP by phagocytosis, while the epithelial cells of the intermediate portion took it up by pinocytosis. In contrast, the epithelial cells in the proximal portion of the ES absorbed little HRP. No penetration through the junctional complexes between epithelial cells was observed in either the intermediate or the proximal portion at any interval after the injection of HRP. This finding indicates that these junctional complexes are impermeable to intraluminal HRP.

Absorption↗
PubMed1992

Mechanism of immune complex-mediated inner ear diseases.

Tissues of the stria vascularis of normal rabbits were collected as cochlear antigen and injected into the foot pad of guinea pigs. The mechanism of development of endolymphatic hydrops was studied by the tracer method. Damage to the capillary endothelium and an increase in vascular permeability were found in the stria vascularis. Therefore, we studied patients with a raised level of immunoglobulin (Ig) G-class circulating immune complexes (CICs). Hearing loss was found in 3 of 22 patients with significantly elevated IgG CIC levels (13.6%). The relationship between inner ear disease and the presence of CIC was considered to be very significant. The possible mechanism of CIC-mediated inner ear diseases is discussed.

Adult↗
PubMed1991

Endocytotic activity of the free floating cells and epithelial cells in the endolymphatic sac: an electron microscopic study.

The fine structure and its functional properties of both free floating cells and epithelial cells in the endolymphatic sac after injections of India ink particles or polystyrene latex beads, 0.24 micron in diameter, into the endolymphatic space, were studied using light and electron microscopy. Twenty-four to 48 hours after injections, these foreign materials had accumulated in the lumen of the endolymphatic sac and a large number of them were ingested into free floating cells, most of which appear to be macrophages. Granular leucocytes taking up the foreign materials into the cytoplasm were also recognized in the sac lumen. A few of these leucocytes passed through the epithelium and migrated to the subepithelial connective tissue, while the others were degenerated and phagocytosed by the free floating cells in the lumen of the sac. In addition to the free floating cells, ink particles, latex beads, and degenerated leucocytes were endocytosed into some of the epithelial cells. As we reported previously, the epithelial cells were clearly classified into two types; type-1 epithelial cells (cytoorganelle-rich cells) and type-2 epithelial cells (filament-rich cells). The foreign materials and degenerated cells were taken up mainly into the type-1 epithelial cells, while the type-2 epithelial cells did not show so marked endocytotic activity in comparison with the type-1 epithelial cells. Thus, it becomes clear that the endolymphatic sac plays an important role in the endocytotic activity for foreign materials and waste products, and both the free floating cells and the type-1 epithelial cells of the sac have strong endocytotic activity.

Animals↗
PubMed1991

Cellular localization of rat Isk protein in the stria vascularis by immunohistochemical observation.

A novel rat membrane protein, termed Isk protein, that exhibits a voltage-dependent potassium channel activity was first reported through molecular cloning combined with an electrophysiological assay (Takumi et al., 1988). In the present study, we made an attempt to identify the cellular localization of the rat Isk protein in the stria vascularis using two types of antibodies that specifically react with the distinct parts of the rat Isk protein. Immunohistochemical analysis showed that the rat Isk protein was present only on the endolymphatic surface of the marginal cell. The possibility that the Isk protein is involved in potassium permeation in the luminal membrane of the marginal cell will be also discussed.

Amino Acid Sequence↗
PubMed1991

Capillary permeability and basolateral endocytic pathway of the epithelium in the mouse endolymphatic sac in vivo.

The capillary permeability and the basolateral endocytic pathway of the mouse endolymphatic sac (ES) epithelium were examined in vivo using intravenous injection of horseradish peroxidase (HRP). The capillaries of the ES were classified as either fenestrated or non-fenestrated. Because dense reaction products were observed soon after injection of HRP in macrophages near both types of capillaries, they were both considered to be permeable to macromolecules. In non-fenestrated capillaries, the basement membrane and small vesicles of the endothelium of the ES were stained with reaction product. These non-fenestrated capillaries were considered to be of muscle type. After 15 min, ES epithelial cells absorbed HRP basolaterally, and the multivesicular bodies and lysosomes of epithelial cells were stained with reaction product. The process of basolateral absorption in the ES epithelium was similar to that in the intestinal epithelium. Our results provide further evidence that the ES is a metabolically active organ which plays an important role in fluid transport in the inner ear.

Absorption↗
PubMed1991

Transport of 5-hydroxydopamine and horseradish peroxidase through the perilymph-endolymph barrier.

The distribution of 5-hydroxydopamine (5-OHDA) and horseradish peroxidase (HRP) in the cochlea was examined by light and electron microscopy after perilymphatic perfusion. Reaction product of 5-OHDA was observed along the endolymphatic surface of the cochlear duct in both 10-minute and 30-minute perfusions, while that of HRP was observed only in the 30-minute perfusion. Both tracers were found in pinocytotic vesicles of Reissner's membrane, Claudius' cells, and Hensen's cells. No labeling was seen in tight junctions of the epithelial cells lining the scala media. The epithelial cells of the spiral prominence showed various degrees of degeneration in the 5-OHDA experiment. These morphologic findings suggest that 5-OHDA and HRP can enter the endolymphatic space from the perilymphatic space by pinocytosis and that the degree of transport depends on the size of the particles.

Animals↗
PubMed1991

Centric and eccentric VOR tests in patients with Menière's disease and vestibular Menière's disease.

Pendular rotation in the eccentric position produces the same angular stimulation as that in conventional pendular rotation and, in addition, involves linear centrifugal and tangential acceleration forces which act on the otolith organs. In the eccentric position, normal subjects showed an increase in gain at 0.64 Hz, when compared with the gain with the head in the centered position. Therefore, we concluded that it is possible to diagnose otolith dysfunction by this comparison. In this study, we applied centric and eccentric pendular rotation tests to patients with Menière's disease and vestibular Menière's disease and investigated their otolith function. Patients with Menière's disease or vestibular Menière's disease within 1 month after the first attack or the most recent attack showed no gain enhancement with eccentric rotation. However, others showed gain enhancement with eccentric rotation. Therefore, we concluded that there seems to be no difference in the otolith function, especially in utricular function between Meniere's disease and vestibular Menière's disease.

Adult↗
PubMed1991

Vascular permeability of the stria vascularis in experimental endolymphatic hydrops.

Vascular permeability of the stria vascularis was morphologically examined in hydrops animals, using the tracer method of horseradish peroxidase (HRP). The reaction product of HRP was observed in the capillary of the stria vascularis, not outside of it. The finding suggests that the vascular permeability of the stria vascularis is unchanged in Kimura's hydrops model.

Animals↗