Search PubMed⌕ Search

Biomedical subjects

H Masutani

Publications and source records attributed to H Masutani.

97 records · Page 6Linked to original sources
PubMed1986

Scanning electron microscopy of the microvascular system in the inner ear.

In the present work, vessels casts in the inner ear of the rat and guinea pig, prepared by casting method using Mercox resin, were subjected to scanning electron microscopic examination and following results were obtained: In adult guinea pig, numerous capillary nets were found in the following parts: stria vascularis, spiral ligament, spiral prominence, Corti's organ, spiral ganglion, plexus cochlearis, semicircular ampulla, saccule, utricle, and endolymphatic sac. These were consistent with functionally and morophologically important areas in the inner ear. In the central side of the area with capillary nets, arterioles were found to run throughout, like a complex coil, and peripheral capillary diameter was found to be unchanged in an experiment in which the injection pressure was altered, thus autoregulation of blood flow into these important areas is assumed. Vessels in the planum semilunatum were found to form a specific loop-shaped route, where secretion and reabsorption of endolymph is thought to occur. After kanamycin injection into the tympanic cavity, stenosis was observed in capillary nets in the cochlear lateral wall. In guinea pigs on the 30th day of fetal life, the main stem of the inner ear vessel had already formed; however, the peripheral capillary nets were as yet immature in form and vessel density was low.

Alprostadil↗
PubMed1985

The ciliary activity of the middle ear lining in some pathological states.

The ciliary activity in some pathological middle ear lining was discussed with special reference to the morphology of the epithelial cells in this paper. The changes in ciliary activity due to in vitro Staphylococcus aureus injection did not practically show any differences between the sites. On the other hand, the time-course changes in ciliary activity after in vivo S. aureus injection were found to differ between the sites. Ciliary activity was rather accelerated at the proximal site, while it was decelerated at the distal site. Few changes but for sporadic small compound cilia were observed at the proximal site, and some inflammatory changes were noted at the epithelium of the distal site. SO2 exposure affected the middle ear lining of rabbits. Fourteen days after 4 week's exposure to SO2, the middle ear lining displayed declined ciliary activity and many signs suggestive of secretory asthenia. In addition, the middle ear lining of rabbits given about 600 mg carbocysteine, both during and 2 weeks after the exposure displayed excellent ciliary activity and normal morphology of the epithelial structure.

Animals↗
PubMed1983

Enhancement of ciliary action by a beta-adrenergic stimulant.

It is known that beta-adrenergic stimulants enhance mucociliary transport in the respiratory tract. The present study clearly indicated that such an enhancement resulted from not only the alteration in secretory function but also the direct stimulation of ciliated cells. However, the enhancement of ciliary beating depended on the morphological changes in ciliated cells. On the other hand, the effect of terbutaline aerosol, a beta-adrenergic stimulant, on patients with chronic sinusitis was evaluated by paranasal sinus radiography. Consequently, marked improvements in shadows were achieved after 4 weeks in 40% of the cases examined.

Adult↗
PubMedDate not supplied

Observation of the otolithic membrane by low-vacuum scanning electron microscopy.

Untreated specimens (i.e. not fixed, dehydrated or embedded) of the otolithic membrane from the sacculus of guinea pigs were observed at the ultrastructural level by low-vacuum scanning electron microscopy (LVSEM). This technique revealed the presence of a 15- to 20-mu m-thick layer of an amorphous substance (the supraotolithic cupula zone) on the surface of the otoliths, which was not detectable by conventional methods. Elemental analysis of this substance revealed relatively high concentrations of oxygen, sodium, phosphorus, chlorine, potassium and calcium. This amorphous substance was thought to have a role in fixing the otoliths onto the sensory epithelium. In addition, the tips of the triangular portions of the otoliths were not sharp as shown by conventional SEM and were seen to be more rounded by LVSEM.

Animals↗
PubMedDate not supplied

Temporal bone pathology of a patient with cochlear implant.

A 66-year-old man with profound total deafness received a 22-channel cochlear implant. After surgery, his hearing improved and the postoperative course was uneventful except transient vertigo. The patient died of lung cancer after 2.5 years. Twelve hours after death, the temporal bone was harvested for histological and electron microscopic examination. The mastoid air cells were preserved, although a few mucosal folds were present. The Dacron mesh tie had largely been absorbed, but part remained embedded in fibrous tissue. No inflammation was noted in the tympanic cavity or the round window through which the electrodes were inserted. In the cochlea, the scala tympani was filled with fibrous tissue at the site of electrode insertion. The scala media had collapsed, while the organ of Corti and stria vascularis showed degeneration. Osseous spiral bundles and spiral ganglion cells were noted, though reduced in number.

Aged↗