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T Sekitani

Publications and source records attributed to T Sekitani.

At least 37 records · Page 2Linked to original sources
PubMed1993

Experimental reactivation of HSV-I in rat vestibular ganglia.

Rats with no clinical symptoms after inoculation were administered with cyclophosphamide in order to reactivate HSV-I in the vestibular ganglia. After this immunosuppression, the vestibular ganglia, trigeminal ganglia, cerebrum, cerebellum and brainstem were examined immunohistologically in order to detect HSV-I. HSV-I antigen could not be detected by using indirect immunofluorescence or the ABC method, however, it could be detected by using the PCR method. In this study, latent infection of HSV-I was shown but reactivation could not be established. We need further investigations to determine the reactivation of HSV-I in the vestibular ganglia, to obtain an animal model of vestibular neuronitis.

Animals↗
PubMed1993

Light and electron microscopic features of the rat vestibular ganglion cells.

The vestibular ganglion cells of the rat were characterized with regard to the cytoplasmic structure by light and electron microscopic observation. Light microscopy revealed four types of cells, depending upon the characteristics and distribution of Nissl granules. Electron microscopy gave a definite classification of these types by the arrangement and distribution of the roughly surfaced endoplasmic reticulum and neurofilament. The characteristics of the ganglion cells are discussed in relation to their size and function.

Animals↗
PubMed1993

Ultrastructure of the chick vestibular ganglion and vestibular nucleus. A scanning electron microscopic study.

The fine structure of the chick vestibular ganglion and vestibular nucleus was studied in three dimensions using a scanning electron microscope (SEM). NaOH and OSO4 maceration methods were applied to observe the configuration in the mechanically torn specimens. Also, Tanaka's aldehyde prefix OSO4-DMSO-OSO4 method (A-O-D-O method) was applied to observe the intracellular structure in the fractured specimens. The surface of the ganglion cell and the nerve processes were seen to be covered with abundant thin fibrous tissues in the specimen treated with OSO4 maceration. This surface fibrous tissue was completely removed with the NaOH maceration method. As a result, the ganglion cell and nerve processes could be seen to be enveloped in the myelin sheath. In the fractured vestibular ganglion treated by the A-O-D-O method, there were three patterns of perikaryal myelination in the vestibular ganglion cells: heavily myelinated, lightly myelinated, and unmyelinated, respectively. In the perinuclear region of the vestibular ganglion cell, well developed and aggregated cytoplasmic organelles such as endoplasmic reticulum, mitochondria, and Golgi apparati were observed. In the perinuclear region of the Schwann cell relatively large mitochondria were characteristically observed. In the fractured view of the vestibular nerves, most of vestibular fibers were compactly myelinated. In the vestibular nucleus, the gathering of the neuronal cells were observed with the NaOH maceration method.

Animals↗
PubMed1993

The expression of maturation factors in the vestibular ganglia in the human fetus.

The expression of laminin, Na+, K(+)-ATPase, carbonic anhydrase (CA) isoenzymes and calcitonin gene-related peptide (CGRP) in the human fetal vestibular ganglia was studied by immuno-histochemistry. In the 12-week-old fetus, the cell surface of the vestibular ganglion cells was positive for laminin. In the 14-week-old fetus, a few vestibular ganglion cells were positive for CA II. In the 15-week-old fetus, the cell surface of the vestibular ganglion cells and the nerve fibers were strongly labelled with laminin. CGRP positive nerve fibers were found in the ganglia. In the 16-week-old fetus, some ganglion cells were labelled with Na+, K(+)-ATPase. CA II stained the vestibular nerve fibers as well as the vestibular ganglion cells. The results suggest that these substances may be used as histological markers of maturation and innervation of the human vestibular ganglion cells.

Abortion, Induced↗
PubMed1993

Development of the chick vestibular ganglion and its nerve terminating in the endorgan.

We investigated the morphological maturation of the vestibular ganglion and its dendrites terminating in the sacculus of the chick embryo. The cytoplasm of the ganglion cells had acquired a granular feature due to the abundance of ribosomal clusters and rER by the 13th day of incubation. The myelination of the dendrites occurred before that of the perikarya. Compact myelin of the dendrites was observed on the 13th day of incubation, while that of the perikarya was observed in the 20th day of incubation. Nerve endings of afferent and efferent character were observed first in the sacculus on the 13th day of incubation. Positive immunoreactvity of substance P was observed on the 13th day of incubation. It is suggested that the morphological basis of functional activity is present on or around the 13th day of incubation.

Age Factors↗
PubMed1993

Vestibular neuronitis evaluated by the combined galvanic test.

Forty-two patients with unilateral vestibular neuronitis were examined by the combined galvanic test (CGT), consisting of the galvanic eye movement test (GEMT) and the galvanic body sway test (GBST). Results of the CGT were evaluated with respect to the time period from the onset of vestibular neuronitis. A favorable recovery was observed earlier with the GBST than the GEMT. We believe that this discrepancy may be due to the difference in compensation between the vestibulo-ocular reflex and the vestibulo-spinal reflex.

Adult↗
PubMed1993

Interpretation of the combined galvanic test. Findings from cases with vestibular neuronitis.

The combined galvanic test (CGT) was developed in our department for simultaneous recording of galvanic eye movement test (GEMT) and galvanic body sway test (GBST). Twelve cases of vestibular neuronitis were studied first with the caloric test, and then with the CGT. The findings of the caloric test corresponded to those of the GEMT, but did not always correspond to those of the GBST. Thus we suggest that the GBST reflects an abnormality in a system different from that reflected by the caloric test and GEMT. It is likely that the caloric response mainly originates from the semicircular canal system. Thus the GEMT may reflect an abnormality in the semicircular canal system, while the GBST reflects an abnormality in the otolithic system. The CGT may thus be a feasible method of differentiating the disorders of the semicircular canal system from those of the otolithic system in the vestibular nervous system.

Adult↗
PubMed1993

Glial fibrillary acidic protein-like immunoreactivity in the human fetal inner ear.

The distribution of glial fibrillary acidic protein (GFAP)-like immunoreactivity (IR) was analyzed in the human fetal inner ear using immunohistochemical techniques. In the 11-week-old human fetal cochlea, nerve fibers labelled with GFAP had reached the basilar membrane, but innervation stained by antisera against GFAP to the hair cells reached only as far as the basal coil. In the 11-week-old human fetal vestibular organs, little GFAP-IR was present in the epithelia. In 14- and 15-week-old human fetal cochleae, rich immunoreactive neural networks were observed, including the inner spiral bundle. Many immunoreactive sites were found below inner hair cells in all coils. Outer spiral bundles in the first, second and third rows in the basal coil were labelled, but the outer spiral bundle in the third row in the apical coil was not stained by the antisera. In the macula utriculi, many heavily stained sites and a rich immunoreactive network in the sensory epithelium were labelled, while considerably fewer positive nerve fibers and sites were present in the sensory epithelia in the macula utriculi and cristae ampullares. These results suggest that GFAP-IR is a very useful marker of differentiation of Schwann cells in the peripheral nerve in the human inner ear.

Cell Differentiation↗
PubMed1993

Tympanic membrane temperature in a patient with vertigo.

Tympanic membrane temperature (TMT) is greatly influenced by the internal carotid artery and the jugular vein. Average human brain temperature is influenced by the differences between the temperature of the internal carotid artery and of the jugular vein. TMT has been used extensively as an indicator of brain temperature. Tympanic membrane temperature was measured in six healthy men (control group) and one patient with vertigo. In the control group, TMT showed considerable circadian changes parallel to the core temperature. In the patient with vertigo, TMT varied widely after the attack of vertigo. These data can provide a basis for the understanding of vertigo attacks.

Body Temperature↗
PubMed1993

The otolithic organ in the developing chick embryo. Scanning electron microscopic study on the utricular macula.

The long and short axes of utricular maculae were measured to calculate growth curves using an ocular micrometer under stereomicroscope. The mean lengths of the long and short axes on the 6th incubation day were 0.06 mm and 0.05 mm, respectively. Thereafter: 1.00 mm and 0.74 mm on the 11th incubation day; 1.34 mm and 1.03 mm on the 15th incubation day; and on hatching 1.51 mm and 1.07 mm, respectively. The surface structure, particularly the otoconia and the sensory hairs of the utricular maculae, on the 4.5th incubation day to the 7th post-hatching day of White Leghorn chicks were observed with a scanning electron microscope (SEM). A number of microvilli and primary cilium on the inner surface of the otocyst were found between the 4.5th and the 5th incubation day. Immature sensory hairs appeared on the 5th incubation day. The polarity of the sensory hairs became evident on and after the 9th incubation day. Mature sensory hairs were seen all over the utricular maculae between the 1st and the 3rd post-hatching day. Mature sensory hairs were mainly seen near the striola, and immature ones peripherally. Then, the various forms in the maturation phase of sensory hairs were seen between the striola and the periphery. These arrangements suggest some process of maturity from the peripheral region to the central striola region. Immature otoconia were first seen on the 6th incubation day. Mature otoconia were recognized on and after the 11th incubation day, and they were observed on the whole surface of the utricular maculae. Global substances on the macula with a rough surface and spongy structure were observed suggesting otoconial precursors transforming themselves into otoconial crystals.

Animals↗
PubMed1993

Vestibular compensation in vestibular neuronitis. Long-term follow-up evaluation.

We evaluated vestibular function, especially for positional, head shaking and caloric nystagmus, in 43 patients with vestibular neuronitis, for long periods from the onset. The results suggested that in these cases of vestibular neuronitis, which were studied for more than 10 years after onset of the disease, the disease may still be in the uncompensated stage or may have worsened in the partially compensated stage.

Adolescent↗
PubMed1993

[Motility of isolated vestibular hair cells induced by potassium].

Many studies of the outer hair cells in cochlea have demonstrated active motility. However, very few studies have been done on vestibular hair cells. This study was designed to demonstrate the motile responses of isolated vestibular hair cells of the chick, induced by potassium promoting contraction. Reversible cell shape changes were observed in 4 of 6 type I hair cells and 3 of 5 type II hair cells by applying the contraction solution. The cell shape changes were revealed mainly in the cuticular plate and infracuticular region. It was suggested that contraction in the cuticular plate of the isolated hair cells might be converted into tension which increases the stiffness of the sensory hairs and restricts their motions, based on the results of the present study, and the structure of contractile proteins and hair behaviors reported by previous investigators.

Animals↗
PubMed1993

[Paranasal sinusitis due to Pasteurella multocida].

A case of paranasal sinusitis due to Pasteurella multocida (P. multocida) is reported. A 39-year-old woman presented with chief complaints of rhinorrhea and headache. The patient kept a cat in her house and kept such close contact with it as to wake up by being licked every morning. Bacteriological examination revealed P. multocida isolated from her nasal discharge and also from the saliva of the cat kept by the patient. The two isolates were compatible with respect to biochemical properties, serotype and drug susceptibility. Therefore, P. multocida infection in this case was considered to have originated from the pet cat. P. multocida infection has been increasing recently. One of the reasons is a pet boom. In order to prevent acquiring the infection from a pet animal, we should have knowledge about this infection, advise the patient to avoid close contact with pets, and provide valuable information concerning these problems to society from the viewpoint of zoonosis.

Adult↗
PubMed1993

Vestibular endorgan of the frog after the space flight and postural alteration of the neurectomized frog--its morphological and functional resilience.

The vestibular organ of frogs returned from space were observed by SEM. Morphology of the sensory epithelia was normal, including ultrastructure, such as tip links and side links. The frogs' behavior and vestibular morphology after various types of vestibular neurectomy were studied. Vestibular neurectomy resulted in tilting posture toward that side. This tilting gradually decreased to zero and the nerve regenerated. When the same nerve was cut again after postural recovery, the tilting angle was smaller and recovery period was shorter than after the first neurectomy. When the bilateral nerves were cut and neural regeneration was inhibited on one side, tilting slowly developed toward that side. These results show that frogs' postural change is modified by both central compensation and peripheral vestibular function.

Animals↗
PubMed1993

Follow-up of square drawing test in vestibular neuronitis.

The square drawing test (SDT) devised by Sekitani (1975), which is a modification of Fukuda's vertical writing test, was performed to evaluate vestibular dysfunction in 15 patients with vestibular neuronitis followed up for a long period. In particular, two parameters (distance and total length) were analyzed in the present study. Distance was analyzed by dividing the 15 cases into 3 groups. The largest group showed a tendency to shorten at an early stage. Total length was examined by dividing the 15 cases into 3 groups. The largest group showed a tendency towards macrographism at an early stage. It was found that as the degree of caloric responses recovered, the range of distance and total length decreased. Considering the correlation between parameters of the SDT (distance and total length) and caloric responses we concluded that the SDT is a feasible method to evaluate and follow up patients with vestibular dysfunction.

Adolescent↗
PubMed1992

Expression of carbonic anhydrase isoenzyme-like immunoreactivity in the limbus spiralis of the human fetal cochlea.

The distribution of carbonic anhydrase isoenzymes (CA I, II, III, V) was analyzed the 14-, 15- and 16-week-old human fetal cochleae using immunohistochemical methods. The interdental cells in the limbus spiralis were strongly labelled with antibodies against CA I and III and the spiral ligament was also positive for CA I and III. The stria vascularis and organ of Corti were however negative for CA I, II, III and V. These results suggest that the interdental cells in the human fetus may be related to fluid and ion transport of endolymph especially in the early stages of development.

Basilar Membrane↗
PubMed1992

Distribution of tyrosine hydroxylase-like immunofluorescence in guinea pig vestibular ganglia and sensory areas.

The distribution of tyrosine hydroxylase (TH)-like immunofluorescence was analyzed in the guinea pig vestibular ganglia and end organs using a monoclonal antibody to TH. TH was chosen as a marker for the sympathetic fibers because TH regulates the first step of catecholamine synthesis by converting tyrosine to dopa. In the vestibular ganglia, there were TH-positive nerve fibers having distinct varicosities surrounding the vestibular ganglion cells. In the sensory areas, there was a sympathetic plexus in the subepithelial tissue of the saccule, the utricle, and the crista ampullaris. We speculated that the sympathetic innervation has a direct influence on the vestibular ganglion cells and diffuse influence on the capillary permeability.

Adrenergic Fibers↗