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Biomedical subjects

T Sekitani

Publications and source records attributed to T Sekitani.

At least 55 records · Page 3Linked to original sources
PubMed1992

Expression of carbonic anhydrase isoenzymes in the developing endolymphatic sac of the human fetus and the mouse embryo.

The distribution of carbonic anhydrase isoenzymes (CA) was analyzed in the developing endolymphatic sac (ES) of the mouse embryo and human fetus using immunohistochemical method. The primordial ES epithelium was labelled with CA I and CA II, but was weakly labelled with CA III and CA V. In the thirteenth and fifteenth gestational day (GD) mice, the ES epithelium was positive for CA I and CA II. After seventeenth GD, the ES epithelium was however weakly positive for CA I and CA II. In the 11 and 12 week old human fetus, the ES epithelium was strongly labelled with CA I and CA II. In the 16 week old human fetus, the ES epithelium was however weakly positive for CA I and CA II. These results suggest that the fetal ES has an activity of CA and plays a role in the otoconial formation especially in the early stage during evolution.

Animals↗
PubMed1992

Histochemical localization of glycoconjugates in the developing endolymphatic sac and vestibular end organs of the mouse.

The distribution of glycoconjugates in the endolymphatic sac (ES) and vestibular end organs from the 12th gestational day (GD) in the developing mouse to the 6th day after birth was analyzed using six biotinylated lectins: wheat germ agglutinin (WGA), Abrus precatorius agglutinin (APA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin 120 (RCA120), Helix pomatia agglutinin (HPA), concanavalin A (conA). In the 13th and 15th GD sections, the luminal contents in the fetal ES were strongly labelled with lectins, while only a small amount of substance in the ES was labelled with lectins after the 17th GD. In the 13th GD sections, before the cupula and otoconia were formed, the fetal ES started to produce glycoconjugates labelled with WGA, APA, RCA120 and ConA. In the 17th GD sections, the immature cupula and otoconia were strongly labelled with WGA, APA and RCA120. Sugar residues stained by lectins detected in the substance of the fetal ES were the same as those found in the immature cupula and otoconia. HPA only stained the ES epithelium around the 13th and 15th GD. The fetal ES may interact with the formation of the cupula and otoconia, especially in the early stage during evolution and that HPA-reactive glycoconjugates may be related to the intracellular elements of the ES epithelium only during a well-defined phase of development.

Animals↗
PubMed1992

Laminin in the endolymphatic sac and vestibular endorgans of developing chick embryos.

The expression of laminin was analyzed in the vestibular endorgans of chick embryos using immunohistochemical methods. The basement membrane of the otocyst in the 5-day-old chick embryo was positive for laminin. In the 9-day-old chick embryo, the basement membrane of the macula of the saccule and utricle was positive, but the crista ampullaris showed a very weak positive reaction. The basement membrane of the endolymphatic sac in the 11-day-old chick embryo was strongly positive. These results suggest that laminin may be an essential substance with regard to the pathology of the vestibular endorgans. Moreover, the uneven distribution of laminin suggests that the basement membrane plays a role whose importance is yet to be determined in the physiology of the inner ear.

Animals↗
PubMed1991

Protein gene product 9.5 expression in the human fetal cochlea.

The distribution of protein gene product (PGP) 9.5 was analyzed in the human fetal cochlea using the indirect immunofluorescence method. In the 12- and 14-week-old human fetuses, the cells of the greater epithelial ridge and the lesser epithelial ridge were overall labelled with PGP 9.5, while the stria vascularis and the Reissner's membrane did not exhibit any staining. Spiral ganglion cells and cochlear nerve fibers were labelled with PGP 9.5 and PGP 9.5-positive nerve fibers made contact with the basement membrane of the Corti primordium in the 12-week-old human fetus. These results suggest that PGP 9.5 might be used as a histological marker of maturation and innervation in the human cochlea.

Biomarkers↗
PubMed1991

Glycoconjugates in the human fetal endolymphatic sac as detected by lectins.

The distribution of glycoconjugates in the 11 to 16 weeks old human fetal endolymphatic sac (ES) was analyzed using six biotinylated lectins; Wheat germ agglutinin (WGA), Abrus precatorius agglutinin (APA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin 120 (RCA120), Helix pomatia agglutinin (HPA), Concanavalin A (ConA). In the 11 week old human fetus, fluorescent reactions with WGA, APA, RCA120 and ConA were detected in the ES. There was almost no reaction with HPA and UEA-I. In the 14 week old human fetus, however fluorescent reactions with HPA and UEA-I appeared. This result suggests that the presence of glycoconjugates changes during the maturation process of the ES. Glycoconjugates detected with HPA were related to the epithelial cell elements of the ES epithelium. The reaction with UEA-I suggests that the stainable substance present in the ES lumen may be secreted locally by the ES itself.

Concanavalin A↗
PubMed1991

Latent HSV-I infection in rat vestibular ganglia.

The vestibular ganglia of rats having no clinical symptoms after inoculation of HSV-I were examined by Polymerase Chain Reaction (PCR) in order to prove latent HSV-I infection. The rats were divided into two groups: one inoculated with HSV-I into the middle ear cavity (m.i. group), and the other into the peritoneal space (i.p. group). In the m.i. group, 67% of the vestibular ganglia on the inoculated side and 0% on the opposite side were positive. In the i.p. group, 60% of the vestibular ganglia on both sides were positive. These data indicate that HSV-I can establish latent infection in the vestibular ganglia. Furthermore, we assumed that reactivation of HSV-I genomes in the vestibular ganglia might lead to disorders of the vestibular system.

Animals↗
PubMed1991

Glycoconjugates in the otolithic organ of the developing chick embryo.

The presence of glycoconjugates in the otolithic organ of developing chick embryos was investigated histochemically using lectins. On the 6-day-old chick embryo, intense labelling with lectins was observed in the sensory epithelium, on the surface of the epithelium and on the immature otoconia. The otoconia were intensely labelled with lectins at every stage of the chick embryos, while the labelling with lectins in the sensory epithelium became weaker with the maturing of the otoconia. In TEM observation, the secretory granules of the supporting cells of the sensory epithelium were labelled with lectin. The reaction of lectin was more intense in the electronic dense zone of the otoconium than in the electronic lucent zone at every stage of the chick embryos. These findings indicate that the precursors of the otoconia are secreted by the supporting cells of the sensory epithelium and that glycoconjugates play an important role in otoconial formation.

Animals↗
PubMed1991

GABA distribution in the central vestibular system after retroauricular galvanic stimulation. An immunohistochemical study.

The changes of the neurotransmitter (GABA) distribution in the brain stem of rats by retroauricular galvanic stimulation were investigated using the immunohistochemical method. In the lateral vestibular nucleus GABA-like immunoreactivity was more intensive on the side ipsilateral to the anodal stimulation than on the other side. It is concluded that retroauricular galvanic stimulation causes some changes in the inhibitory activity of the lateral vestibulo-spinal tract and of the spinal motor neuron.

Animals↗
PubMed1991

Cell culture study of the vestibular ganglion cells. Morphology and immunohistochemical activity.

Incubation of vestibular ganglion cells from the rat fetus and chick embryos was successfully done demonstrating bipolar cells and two types of multipolar cells, small round cells and large cells, in the cell cultures produced. Vestibular ganglion cells were found to be highly irregular in size. Furthermore, the presence of neurotransmitters (choline acetyltransferase and substance P) was confirmed immunohistochemically. Substance P positive cells had many bipolar cells and some multipolar cells. However, choline acetyl transferase positive cells had some small multipolar cells but few bipolar cells. These findings suggest that all vestibular ganglion cells do not have the same function.

Animals↗
PubMed1991

Analysis of the fast phase of per-rotatory nystagmus.

We studied the relationship between the fast phase velocity and amplitude of per-rotatory nystagmus resulting from constant angular acceleration and deceleration stimulation. The relationship was nonlinear and was best fit to the exponential equation. We established the uppermost point of the data distribution along the resolution curve. In normal subjects the angular rotatory stimulation using a computer-controlled rotatory chair (ROKOS-6) with 5 degrees/s2 rotation was the best among three kinds of angular rotatory stimulation (1.2 and 5 degrees/s2). Compared to peripheral vestibular disorder the uppermost point of nystagmus had a tendency to be larger in amplitude in some cases with central vestibular disorder. In many cases with sudden deafness the same tendency was seen.

Acceleration↗
PubMed1991

Compensatory process of vestibular neuronitis. From findings of combined galvanic test and caloric test.

The compensatory process of vestibular neuronitis in 7 patients was followed up and evaluated using the Combined Galvanic Test (CGT) and other neuro-otological data. CGT is the simultaneous recording of both galvanic eye movement (GEM) and galvanic body sway (GBS), and has proved to be reliable in the diagnosis of retrolabyrinthine disorders. The results were as follows: The subjective symptoms remained in 3 cases from 1 month to 1 year. The recovery of the GBS response was seen earlier than that of both GEM and caloric responses. The recovery of GEM and caloric responses was observed at almost the same time. We observed the favorable recovery process of caloric response and GEM response in some cases which had recovery of GBS response within 4 weeks and suggest that the system of GBS response is different from that of GEM and caloric response. However, the systems of the latter two may be the same. We assume that the recovery of GBS response is earlier than that of GEM and caloric responses because the otolithic system recovers more easily than the semicircular canal system. The CGT and caloric test were reliable in examining the compensatory process of vestibular neuronitis.

Adult↗
PubMed1991

Effect of electric stimulation on vestibular compensation in guinea pigs.

The effect of electric stimulation on vestibular compensation was studied in guinea pigs. Pharmacological labyrinthectomy was performed by injecting chloroform into the right middle ear under light ether anesthesia. The guinea pigs were divided into four groups: a control group which was not electrically stimulated after labyrinthectomy, a group stimulated with 0.6 mA square wave, a group stimulated with 0.3 mA square wave, and a group stimulated with 0.6 mA pulse wave. Electric stimulation, which started 1 h and 15 min after labyrinthectomy, was given through retroauricular electrodes. Nystagmus and head deviations were recorded and analyzed to assess the process of compensation at 1, 2, 3, 4, 5, 8, 12, 18 and 24 h after labyrinthectomy. Electrically stimulated groups, especially group 0.6 mA square wave and group 0.6 mA pulse wave, showed faster compensation in nystagmus and head-body deviation than the control group. Therefore, in this study, electric stimulation seemed to contribute favorably to vestibular compensation.

Animals↗
PubMed1991

[Localized amyloidosis of larynx. A case report and immunohistochemical study].

A case of the localized laryngeal amyloidosis was reported. The patient was a 51-year-old female who complained of hoarseness for about a year. Pathological study on the biopsy specimen taken from both the subglottic area under laryngeal microsurgery showed the deposit of amyloid. Laryngeal microsurgery showed the deposit of amyloid at bilateral subglottic area. Electron microscopic study disclosed a typical amyloid fibrillar structure. Amyloid protein, in this case, was confirmed as protein A lambda appeared through the potassium permanganate treatment and immunoperoxidase technique (ABC method).

Amyloid↗
PubMed1990

[Effect of retroauricular galvanic stimulation on the central vestibular system--immunohistochemical evaluation of GABA].

The changes of the neurotransmitter (GABA) distribution in the brain stem of the rats by retroauricular galvanic stimulation were investigated using immunohistochemical method. Twenty-one rats were divided into two groups: the control group which received no galvanic stimulation, and the galvanically stimulated group which received anodal galvanic stimulation (unipolar monoauricular, 5 mA in intensity, 500 msec of duration, 1 Hz in frequency) for 30 minutes. The specimens obtained as usual strict procedure for histological investigation were stained immunohistochemically using antisera against GABA. The results were as follows: 1. In the control group, GABA-like immunoreactivity was observed in all four main vestibular nuclei. In the superior, medial, and descending vestibular nuclei GABA-like immunoreactivity was found in the small cells and the terminals. Giant cells in the lateral vestibular nucleus were surrounded by GABA immunoreactive terminals. 2. In the galvanically stimulated group GABA-like immunoreactivity showed recognizable laterality in the lateral vestibular nucleus where GABA-like immunoreactivity surrounding giant cells showed more intensive on the side ipsilateral to the stimulation compared with the opposite side. On the other hand GABA-like immunoreactivity showed no laterality in the superior, medial, and descending vestibular nuclei. 3. It can be concluded that the retroauricular galvanic stimulation cause some changes in the inhibitory activity of the lateral vestibulo-spinal tract and of the spinal motor neuron.

Animals↗
PubMed1989

Vascular leiomyoma of the parotid gland.

Leiomyoma occurrence in the head and neck is rare. Vascular leiomyoma usually occurs in the skin of the limbs. Survey of the literature also revealed that there was no case of vascular leiomyoma in the parotid gland reported in Japan. A 50-year-old man with vascular leiomyoma which developed from the parotid gland was reported. The chief complaint of this patient was a painless preauricular mass on the right side. The tumor was a solitary mass of quail-egg size with round and smooth surface, elastic soft consistency and not tender. The tumor was completely removed under general anesthesia. This patient has been well without recurrence 5 years after operation.

Hemangioma↗
PubMed1989

Histogenetic study of the vestibular ganglion in the developing chick embryo by lectin-horseradish peroxidase methods.

Hatchery eggs of White Leghorn hens were incubated and the vestibular ganglion cells of 3.5- to 6-day-old chick embryos were studied by the lectin-horseradish peroxidase methods (WGA, UEA-1). In the 3.5-day-old chick embryos, the facial-acoustic ganglion mass was recognized close to the otic vesicle. The statoacoustic ganglion reacted to lectins on the rhombencephalic side, indicating that glycoconjugates play a role in the nerve connection between ganglion and rhombencephalon. In the 4-day-old chick embryos, a strong reaction to lectins was observed on the ganglion cell membrane of the geniculate and statoacoustic ganglions, suggesting that glycoconjugates may be related to their differentiation. In 4- and 5-day-old chick embryos, the mesenchymal tissue showed a strong reaction to lectins, suggesting that it plays an important part in the differentiation of the vestibular ganglion.

Animals↗