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Biomedical subjects

A Komatsuzaki

Publications and source records attributed to A Komatsuzaki.

At least 19 recordsLinked to original sources
PubMed1992

Membranous cytoplasmic bodies in the lateral wall of the cat cochlea.

Membranous cytoplasmic bodies (MCBs) were observed both in the intermediate cells of the stria vascularis and in the fibrocytes of the spiral ligament in normal cats. The MCBs in the intermediate cells were round or ovoid, ranged from 1 to 5 microns in diameter, and consisted of 2 to 40 or more layers disposed concentrically about a core. The core was composed of not only cytoplasm but also of mitochondria in various stages of disintegration, empty vacuoles, and many kinds of dense bodies similar to lysosomes. The MCBs in the fibrocytes were similar to those in the intermediate cells, but they were a little smaller in diameter and consisted of fewer than 10 layers. Both in the intermediate cells and in the fibrocytes, MCBs seem to have a phagocytic function.

Animals↗
PubMed1992

Effects of frequency and intensity of sound on cochlear blood flow.

Laser Doppler flowmetry demonstrates that loud sound induces a decrease of blood flow in the cochlea of the guinea pig. In this experiment, we observed the effects of frequency and intensity of sound on cochlear blood flow using 15 guinea pigs. In the first 5 guinea pigs, a Doppler probe was attached to the basal turn of the cochlea and sounds of 6, 7, 8, 9 and 10 kHz were delivered to the ear serially from lower to higher frequency, i.e. from 6 kHz to 10 kHz. In the next 5 guinea pigs, the sound was delivered from higher to lower frequency, i.e. from 10 kHz to 6 kHz. The sound intensity delivered to the ear was changed from lower to higher intensity (80 to 120 dB SPL by 10 dB width) at each frequency. In the last 5 guinea pigs, the blood flow in the basal, second, third, and fourth turns of the cochlea was measured at 120 dB SPL of 10 kHz. No change of blood flow was seen in the cochlear basal turn at 6 and 7 kHz up to 120 dB SPL, but a decrease of blood flow was found at 110 and 120 dB SPL at 8, 9, and 10 kHz. On the other hand, the sound of 120 dB SPL at 10 kHz induced a decrease of blood flow only in the basal turn of the cochlea. Our results suggest that there is a corresponding blood flow area which is sensitive to specific frequency in the cochlea.

Animals↗
PubMed1992

[Jugular bulb position in the cranial base and its relation to cranial venous system].

Target CT images of 147 patients and digital subtraction angiography (DSA) images of 15 patients were examined to assess the relation between jugular bulb position and intracranial veins. First, relation of jugular bulb position to venous volume was examined from CT. The height of the jugular bulb was measured from the lower margin of the tympanic annulus to the apex of the jugular bulb by counting CT slices individually on the both side. The heights of the right and left jugular bulbs were 4.0 +/- 3.9 mm and 2.0 +/- 3.9 mm respectively, indicating that the right jugular bulb was higher than the left, consistent with previous reports. The depth of the sigmoid sinus sulcus, which may reflect the venous volume, was measured on the slice showing the internal auditory canal. The right side was 6.7 +/- 2.2 mm deep, while the left side was 5.3 +/- 2.0 mm in depth. These measurement also showed that the height of jugular bulb and depth of the sulcus of the sigmoid sinus were closely related. The jugular bulb was higher on the side with the deeper sigmoid sinus sulcus (correlation coefficient r = 0.73). Frontal head and neck angiography were performed after bolus injection of contrast medium. Angiographic images were modified and examined by means of a digital subtraction process. A result from angiography was consistent with the measurement of CT. The side with greater venous flow has the higher jugular bulb. And such difference in right and left venous flows was observed at and pproximately to the transverse sinuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography, Digital Subtraction↗
PubMed1992

[Exostosis of the external auditory canal and sensorineural hearing loss in professional divers].

Audiometric survey and endoscopic study of the external auditory canal were performed on a group of 31 professional divers, all of whom had experienced frequent exposure to dysbaric conditions. The results are as follows. 1) Over 40% had exostosis of the external auditory canal. There was no relationship between the incidence of the exostosis and the length of their occupational career as a diver. Many of the divers had hearing loss whether they had exostosis or not. 2) Over 70% had sensorineural hearing loss, taking into account hearing loss due to aging. Most had no experience of inner ear barotrauma on descent, causing sudden a shift in hearing threshold. Deafness was related to the length of their occupational career as a diver. In conclusion, we speculate that repetitive small changes in barometric pressure on the outer ear influences the pressure on the middle ear and further on that of the perilymph, finally damaging the inner ear auditory system.

Adult↗
PubMed1992

[Difference between horizontal enlargement and vertical enlargement of the internal auditory meatus in acoustic neuroma].

Twenty-one patients with acoustic neuroma were investigated. The vertical diameter of the internal auditory meatus was measured by polytomography, the horizontal by target imaging CT. The ratio of the abnormal side to the normal side was calculated in each dimension. Two dimensional ratios were compared with each other in order to investigate the difference between horizontal and vertical enlargement of the internal auditory meatus. The results were as follows: 1) Horizontal enlargement of the internal auditory meatus was greater than that of the vertical one in 15 cases (75%). Vertical enlargement was greater in 6 cases but the difference between the two dimensions was not significant. 2) With horizontal enlargement, the posterior wall of the internal auditory meatus was more extended or destroyed than that of anterior wall. 3) With enlargement of the posterior wall, the bony eminence forming the inner side of the porus was predominantly extended or destroyed in every case.

Adolescent↗
PubMed1992

Ultrastructural findings of capillaries in nasal polyps.

The permeability of capillaries in nasal polyps is very high. The continuous capillary is the typical type but the discontinuous type and fenestrated type are also observed. These fenestrated capillaries are found near the stalk region. Although discontinuous capillaries undoubtedly have high permeability, many morphological findings which show this high permeability are observed even if they are continuous capillaries. There are many endothelial projections into the capillary lumen, well-developed marginal folds and pinocytotic vesicles. The endothelial projections complicatedly agglutinate to another part of the endothelium or projections and sometimes form the reticulation. Morphological findings inhibiting the interstitial oedema are also observed. Several layers of basement membrane appear around the capillaries, endothelial projections into the interstitium and the formation of the appositional junction between the pericytes and endothelium. Well-developed basement membrane inhibits the leakage of large molecules. The large spaces which are enclosed by external projections demonstrate the efficient absorption of interstitial fluid. The external projections and the formation of the appositional junction between pericyte and endothelium may support the findings of the rebirth capillaries. The capillaries in nasal polyps are very small in number. If the capillaries or venules were quickly created the interstitial fluid would be efficiently absorbed in the vessels.

Adult↗
PubMed1991

Primary position upbeat nystagmus. Clinicopathologic study of four patients.

We report an electro-oculographic study (EOG) of upbeat nystagmus and neuroradiological correlations in 4 patients and neuropathological findings in 1 patient. All 4 patients revealed responsible lesions in the lower pontine tegmentum. The EOG data suggest that our patients had a deficit in vertical smooth eye movement balance. The nystagmus stopped or reversed direction during convergence or changes of head position. These EOG findings might be caused by vertical imbalance in the otolithic ocular reflex, superimposed on an imbalanced vestibulo-ocular reflex (VOR), secondary to a damage to the pontomedullary tegmentum.

Adult↗
PubMed1991

Intratympanic gentamicin therapy for Menière's disease placed by a tubal catheter with systematic isosorbide.

In 1974 (6), 6 patients with incapacitating unilateral Meniere's disease were given an empiric treatment with intratympanic gentamicin sulfate via the eustachian tube using a catheter with a small side-branch. These patients showed excellent results, gaining relief from vertigo over a 13-year period. Since 1980 (7. 8), we have treated patients suffering from Menière's disease with isosorbide. When the patients could not be controlled by this therapy, isosorbide was given in addition to intratympanic gentamicin therapy using a tubal catheter. Of 75 patients with Menière's disease who received gentamicin and isosorbide therapy, 41 could be evaluated by the classification of the American Academy of Opthalmology and Otolaryngology (AAOO) in 1987 (9). Three of these patients suffered from repeated attacks of vertigo for 2 years. However, all of them could be easily controlled by additional intratympanic gentamicin or isosorbide therapy on an out-patient basis. Thereafter, of a further 40 patients with incapacitating Menière's disease who received gentamicin and isosorbide therapy, 15 could be evaluated by the AAOO classification. In summary, of the 115 patients with incapacitating Menière's disease treated with intratympanic gentamicin after isosorbide treatment, 56 could be evaluated by the AAOO criteria from 1987 to 1990. These patients ranged in age from 21 to 79 years. Vertigo improved in 80% of the patients: 19 patients (34%) were group A. 22 patients (39%) were group B, 4 patients 7%) were group C and 11 patients (20%) were group D, of whom 9 patients required subsequent endolymphatic-mastoid shunt operations. This treatment also effectively controlled patients with bilateral Menière's disease.

Adult↗
PubMed1991

IgA-mediated inhibition of human leucocyte function by interference with Fc gamma and C3b receptors.

The inhibitory effects of IgA from human colostrum, and IgA1 and IgA2 from human serum on the chemiluminescence (CL) response and phagocytosis of polymorphonuclear leucocytes (PML) to Staphylococcus epidermidis and the CL response to formylmethionyl-leucyl-phenylalanine (FMLP) were studied. The dose-dependent inhibition of the luminol-mediated CL response of human PML to the bacteria was observed in the presence of more than 0.1 mg/ml IgA from both colostrum and serum. The preincubation of PML with a solution of IgA enhanced the suppressive effect of IgA on the cells. Removal of IgA from the reaction mixture after preincubation resulted in recovery, with time, of the response of PML to the bacteria. The bacteria treated with IgA did not give rise to any inhibition of the response. The CL response of PML to FMLP was not affected by the presence of IgA in the reaction mixture. The decrease of phagocytic activity of PML in the presence of IgA resulted in a decrease of NADPH oxidase activity of PML after stimulation with the bacteria as compared with the absence of IgA. The effect of IgA on the receptors of Fc and C3b (CR1) on the surface of PML was measured by monitoring erythrocyte-antibody (EA) or erythrocyte-antibody-complement (EAC) rosette formation and by direct and indirect immunofluorescence techniques using anti-CR1 antibody and Fc-specific antibodies. The presence of IgA in the reaction mixture led to a quantitative decrease in CR1 and the ability to bind IgG to the surface of PML.

Antigens, Differentiation↗
PubMed1991

Histological changes of vestibular nerves and ganglion cells in the acoustic tumor in relation to clinical functions.

The superior vestibular nerves and vestibular ganglion cells were observed electron microscopically in acoustic tumors removed surgically from 15 patients. Furthermore, the sensory cells of the vestibular organs were examined. Histological changes of vestibular nerves and ganglion cells were compared with the caloric responses of the patients. In most cases, the degree of degeneration of myelinated nerve fibers was proportional to the reduced responses of vestibular nerves. The myelinated nerve fibers decreased in number and showed some features of demyelination. The alteration of vestibular ganglion cells was unremarkable in comparison with vestibular nerves. In some cases, the number of lipofuscin granules, vacuolar organelles and amorphous materials markedly increased in the ganglion cells. However, the sensory cells of the vestibular organs appeared normal.

Adolescent↗
PubMed1990

Ultrastructural pathology of the vestibule in patients with acoustic neurinomas: secondarily operated cases after posterior fossa operation.

The vestibular sensory epithelia from two patients with acoustic neurinomas were examined ultrastructurally. Both patients had first undergone posterior fossa operations 8 months and 3 years before residual tumors in the acoustic canals were removed by a secondary translabyrinthine operation. Labyrinthine sensory tissues were also removed for microscopic studies. In case 1, the utricular macula and the lateral and anterior cristae were observed, with all sensory epithelia showing fairly normal findings. Myelinated nerve fibers below the sensory epithelia also appeared normal. In case 2, only the utricular macula could be observed. The sensory epithelium showed severe degeneration, disappearing sensory cells and increasing cytoplasmic filaments of both the sensory cell and the supporting cell. Myelinated nerve fibers below the sensory epithelia were only rarely found.

Adult↗
PubMed1990

[Acute hearing loss in the contralateral ear after acoustic tumor removal].

Two patients suffered from acute hearing loss of the contralateral side after acoustic tumor surgery were reported. The first patient was a 42-year-old-male. He had had a right progressive hearing loss over two years and CT scan revealed a mass of 20mm in diameter in the right cerebellopontine angle. The patient noticed the contralateral hearing loss on next morning after the total removal of tumor by translabyrinthine approach. However he had no complaint of vertigo or facial palsy. An audiogram of the contralateral side just after the onset showed flat type audiogram of sensorineural hearing loss with positive recruitment. With steroid therapy for two weeks, hearing and ABR findings improved and returned to nearly normal. The second case was a 47-year-old male. The patient had chronic renal failure treated by hemodialysis. His hearing loss in the right ear had gradually decreased over two years and an acoustic tumor of 2.5cm in diameter was demonstrated by CT scan. The tumor was removed by translabyrinthine approach. Nine day after the operation, he noted total deafness in contralateral ear and vertigo. He was given steroid hormone and his hearing improved up to 68 dB. Four cases have been reported in the literature. The mechanisms of acute sensorineural hearing loss observed in these cases were discussed. The cause remained unknown, however there were some hypothesis such as the compression to the opposite brainstem, peripheral nerve or feeding vessels by tumor or brain edema after operation, and local vasospasms might be also the cause of hearing impairment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

Bilateral internal auditory canal enlargement without acoustic nerve tumor in von Recklinghausen neurofibromatosis.

The common (and definitive) intracranial tumors in patients with one form of neurofibromatosis (NF), bilateral acoustic NF (NF-2), are bilateral acoustic neuromas. In this study, we present 2 cases with what appears to be another form of NF, namely, NF-1, who showed bilateral enlargement of the internal auditory canals. Bilateral caloric responses were remarkably impaired in both cases; a unilateral sensorineural hearing loss was observed in 1. No tumor was demonstrated in the enlarged internal auditory canals in either case. Although the pathophysiology remains uncertain, some patients with NF-1 show abnormal cochleovestibular function in association with bilateral internal auditory canal enlargement without an acoustic tumor.

Child↗
PubMed1989

[Selective impairment of downward gaze; report of two cases of midbrain and bilateral paramedian thalamic infarction].

Selective paralysis of downward gaze, first described by André-Thomas et al. in 1933, is rare to be observed and not many cases have been so far reported in the literature. Two additional cases of selective impairment of downward gaze have been reported. X-ray CT scan revealed the infarcted areas in the midbrain tegmentum and bilateral paramedian thalami in both cases. Angiographic studies have revealed that the arteries occluded might be the paramedian thalamic arteries and their mesencephalic branches. According to the reported clinico-pathological studies and, in addition, to the results of the physiological studies in animal models, the responsible site of lesion for downward gaze failure is thought to be the rostral interstitial nucleus of MLF (riMLF). In one of the cases (28 year-old female, case 1), while vertical slow pursuit eye movements and upward saccade were normal in speed and range, maximum speed of eyes in voluntary downward saccade was markedly reduced and the eyes moved down slowly as if moving in oil (slow eye movement, viscosité). Passively extending the patient's head while she tried to fix her eyes on an unmoving object (doll's eye phenomenon), the speed of her eyes in downward saccade did not increase. In the other case (45 year-old male, case 2), the patient's voluntary and reflex downward eye movements were completely impaired and he could not look down nor follow the object below extending the horizontal meridian level. With regard to the unique features of abnormal eye movements observed in our cases, the possibility of coexistence of saccadic and slow pursuit eye movement systems in the vertical plane was discussed.

Adult↗
PubMed1988

An electronmicroscopic study of the lateral line organ of the guppy, Poecilia reticulatus var.

We examined the ultrastructure of the lateral line of the guppy, Poecilia reticulatus var. by using both scanning electron microscopy and transmission electron microscopy. The neuromast was seen to be composed of receptor cells, supporting cells and mantle cells. The receptor cell has one kinocilium and approximately 29 stereocilia. Two kinds of nerve endings were found in the basal portion of the receptor cells. These two types of nerve endings were similar to the efferent and afferent nerves reported previously. The cytoplasm of the supporting cells contains numerous mitochondria, filaments and melanin-like granules. The lateral wall of the neuromast is covered by a few layers of crescent-shaped mantle cells.

Animals↗
PubMed1988

Clinical evaluation of medical treatment for Menière's disease, using a double-blind controlled study.

There are great variations in the clinical evaluations of the effectiveness of antivertiginous drugs for Meniere's disease. In our clinical evaluation, subjective and objective signs and symptoms of 128 patients with Meniere's disease and of 98 with other peripheral vestibular disorders were analyzed in a double-blind controlled study comparing adenosine triphosphate (ATP) (300 mg) and betahistine (36 mg) each given daily for 4 weeks. The method of administration was the matched-pair-group-method for this double-blind controlled trial. The attending physicians concluded that ATP was significantly more effective than betahistine in the treatment of Meniere's disease and other peripheral vestibular disorders.

Adenosine Triphosphate↗
PubMed1983

[Clinical studies of cefotiam in otorhinolaryngologic infections].

Cefotiam (CTM) was intravenously or intramuscularly given to 14 patients with infections in the field of otorhinolaryngology including 5 cases with chronic suppurative otitis media. Daily doses of CTM were 1 to 3 g and its administration period was 3 to 10 days. Clinical responses were excellent in 1 patient, good in 8, fair in 2 and poor in 3, the rate of satisfactory clinical responses (excellent and good) being 64.3% (9/14). Staphylococci were most frequently isolated from the clinical materials. As for side effects, elevation of GOT and GPT was observed in 1 patient.

Adult↗