Biomedical subjects

N Yanagihara

Publications and source records attributed to N Yanagihara.

At least 145 records · Page 8Linked to original sources

PubMed1991

[Influence of tonsillar hypertrophy to physical growth and diseases of the nose and ear in school-age children].

The authors investigated the influence of facial tonsillar hypertrophy to physical growth, and diseases of the nose and the ear for 7190 pupils of elementary schools in nine different areas in Japan. Tonsillar hypertrophy seemed to prevent physical growth of pupils of lower grades. In pupils without tonsillar hypertrophy, the number of pupils suffering from rhinitis gradually decreased from 16.9% in the first grade to 8% in the sixth degree. On the other hand, the number of pupils suffering from rhinitis remained to be large, ranging between 20.5% and 29.7% in the group of tonsillar hypertrophy. The number of pupils with hearing loss were much more in the group of tonsillar hypertrophy. Since an only available diagnostic mean of ear disease was an otoscopic examination, a significant number of pupils with serous otitis media may be labeled as hearing loss. For this reason, tonsillar hypertrophy possibly affected the number of pupils with hearing loss. There were no apparent relations between tonsillar hypertrophy and allergic rhinitis, chronic paranasal sinusitis and chronic otitis media.

Body Constitution↗

PubMed1991

Defects in the bony wall of the mastoid bowl: a study based on staged intact canal-wall tympanoplasty.

The incidence and outcome of bony wall defects in the mastoid bowl were studied in 175 ears of 167 patients who underwent staged tympanoplasty by the intact canal-wall technique. In the first stage, the middle fossa dura was exposed iatrogenically in 38 ears and pathologically in eight ears through a defect at the tegmen. In the second stage, the bone defect was cured in 27 ears of the former group and in 3 ears of the latter group. The overall cure rate of the defect in the tegmen during these stages was 65.2 percent (30/46). Exposure of the sigmoid sinus or posterior fossa dura, which had occurred iatrogenically in 12 ears in the first stage, was cured in 11 ears (91.7%) in the second stage. Defects of the anterior wall of the mastoid bowl, i.e., the posterior wall of the external auditory canal, were recognized in 105 ears in the first stage, 91 of which involved pathologic defects of the tympanic scutum caused by cholesteatoma. In the second stage, these defects remained unhealed with cures occurring in only two ears (1.9%), in which a small hole had been created iatrogenically in the middle of the canal wall. Defects in the canal wall due to bone resorption following the first stage operation were noted in the second stage in 26 of 175 ears (14.9%).

Adolescent↗

PubMed1991

Inflammatory pseudotumor of the facial nerve as a cause of recurrent facial palsy: case report.

This is a report of a case presenting recurrent facial palsy due to inflammatory pseudotumor of the facial nerve. The patient was a 41-year-old man suffering from facial palsy on the right side once in 1983, which recurred in 1988. The initial facial palsy was cured after conservative treatments including steroid administration. Three months after the recurrence, the same treatments were attempted without noticeable effect. He was referred to our clinic two and half months later. Electromyographic examination indicated pronounced denervation of the facial nerve. Imaging study including high resolution CT and MRI revealed a mass lesion around the geniculate ganglion. Facial neuroma was initially suspected. Surgical exploration revealed a tumor involving the geniculate ganglion and the horizontal portion of the facial nerve. The tumor was resected through a combined transmastoid and middle cranial fossa approach, followed by nerve grafting. Histologically, the tumor proved to be an inflammatory pseudotumor originating from the nerve sheath, although the etiologic factor causing the inflammation was not verified.

Adult↗

PubMed1990

Protein kinase C subtypes in tissues derived from neural crest.

Subtypes of protein kinase C were determined in tissues derived from neural crest. The bovine adrenal medulla and rat superior cervical ganglia contained type III enzyme as the major subtype with a small amount of type II enzyme. In PC12 cells, treated with or without nerve growth factor, type III was the major subtype but a minor peak which is distinct from types II and III was observed. These results show that the type III enzyme is prevalent in various differentiation stages of neural crest and suggest that the enzyme relevant to the regulation of catecholamine synthesis and release in these cells is type III.

Adrenal Gland Neoplasms↗

PubMed1990

Chronic otitis media and tympanoplasty in aged patients.

Results of tympanoplasty in patients over 60 years old were analyzed mainly in terms of hearing and postoperative course. Tympanoplasty was carried out in 78 ears of 67 patients during the last ten years. The following types of tympanoplasty were employed: type I in 34 ears, type III-Columella in 23 ears, type IV-Columella in 13 ears, and other types in 8 ears. The results were compared to those of 145 ears from 119 patients ranging from 20 to 59 years of age who had undergone tympanoplasty during the last 3 years. In tympanoplasty type I, closure of the air-bone gap within 20 dB was attained in 70% of the patients over 60 years old, 90% in the 50-59 year age group, and 100% in the 20-49 year age group. In type III-Columella, these values were 60, 78, and 94%, respectively. During the postoperative follow-up, perforation of the eardrum recurred in 5 of 78 ears (6.4%) in the patients over 60, in 5 of 52 ears (9.6%) in the 50-59 year group, and in 7 of 93 ears (7.5%) in the 20-49 year group. These results suggested that hearing results were worse in patients over 60 than in the other age groups, even though the incidence of graft failure did not greatly differ by age.

Adult↗

PubMed1990

Sodium/proton exchange in cultured bovine adrenal medullary cells.

We investigated the presence of Na+/H+ exchange in cultured bovine adrenal medullary cells. The intracellular pH in control cells measured by 5,5-dimethyl[2-14C]oxazolidine-2,4-dione was 7.13 +/- 0.02 (n = 6). Removal of Na+ from the incubation medium shifted the intracellular pH down to 6.67 +/- 0.12 (n = 6). Reintroduction of Na+ to the medium caused a rapid recovery in intracellular pH to 7.20-7.30 that was associated with an increase in uptake of 22Na+ by the cells. Both increases in intracellular pH and uptake of 22Na+ were inhibited by amiloride, an inhibitor of Na+/H+ exchange. The recovery of intracellular pH by addition of Na+ was partially inhibited by quinidine, another inhibitor of Na+/H+ exchange, but not by 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid, an anion-exchange (Cl-/HCO3-) inhibitor. Li+ could substitute for Na+ in the recovery of intracellular pH. Carbachol caused an increase in intracellular pH from 7.12 +/- 0.01 to 7.21 +/- 0.02 (n = 10). This increase in intracellular pH caused by carbachol was inhibited by amiloride. These results suggest the existence of an amiloride-sensitive Na+/H+ exchange that regulates the intracellular pH in adrenal medullary cells.

Adrenal Medulla↗

PubMed1990

Middle ear mucosa in Ramsay Hunt syndrome.

We report two patients with Ramsay Hunt syndrome, together with histopathologic findings of the middle ear mucosa near the facial canal. An attempt was made to find specific antigens of varicella zoster virus (VZV) and herpes simplex virus (HSV) by an immunofluorescence method. Histopathologic examination revealed inflammation of the middle ear mucosa. Specific VZV antigens were demonstrated in the cytoplasm and nucleus of elliptically shaped cells and round cells, but no specific antigens of HSV were found. The findings suggest a pathogenetic relationship between VZV infection and inflammatory changes in the middle ear mucosa.

Antibodies, Monoclonal↗

PubMed1990

[Recurrence of perilymphatic fistula].

Recurrence of the perilymphatic fistula is not rare and may be a tough problem for surgical treatment. This is because a graft is usually applied on the ruptured window(s) from the middle ear and therefore the perilymphatic pressure directly acts on the graft. The recurrence may be caused by a technical failure, use of an unsuitable graft material, poor postoperative bedrest, trauma, increased inner ear pressure, etc. In our clinic, the recurrence occurred in 7 of 48 cases surgically treated. Vertigo accompanied with spontaneous or positional nystagmus was seen in all 7 recurrent cases, while only 2 of them complained of worsening of the existing hearing loss. Re-operation was carried out in two patients. In the first case, closure of the round window by the previous operation was found incomplete, and the perilymph leaked through the gap around the graft. In the second case, closure of the round window was complete, but perilymph leaked from the oval window. In order to prevent the recurrence, the operation should be carefully performed by using strong and adhesive tissue as a graft material, applying a glue between the graft and the inner ear window(s), and keeping strict postoperative bedrest.

Adolescent↗

PubMed1990

[Multiple primary cancers of the head and neck].

Multiple primary cancers of the head and neck are not always rare. We have experienced 30 cases of multiple primary cancers in the Department of Otolaryngology, Ehime University School of Medicine from 1976 to 1989. The incidence ranged from 3.6% to 8.9% with flexible criteria. The minimum was 14 of 393 cases of all index cancers, strictly conformed with Warren's definition. The maximum was 29 of 327 cases of index cancers on the mucosal surfaces, including a combination of both head and neck cancers. In view of organic specificity of the index cancers, the incidence was high in the larynx and oral cavity, low in the nasopharynx and maxillary sinus. The concept of "multicentric cancerization" was verified by the result that 60% of the additional cancers were head and neck, esophagus and lung. During following-up studies of oropharyngeal, hypopharyngeal and laryngeal cancers, we have to examine the esophagus periodically due to high risk of occurrence of cancer. To compare the data of multiple primary cancers of the head and neck between institutions, adequate and detailed criteria should be established.

Aged↗

PubMed1990

[Audiological evaluation of the middle ear implant--temporal auditory acuity].

Temporal auditory acuities provided by the middle ear implant (MEI) and by the hearing aid (HA) were compared in ten patients implanted with the MEI. Test sounds used in the experiment were tone bursts [rise and fall time: 25 msec, duration (t): 982-1000 msec, interval (T): 1000 msec] of 500 Hz or 2000 Hz at 70 dBSPL. A speaker was placed in front of a subject one meter apart. At first, the subject adjusted the gain control of outer unit at the most comfortable loudness level. He heard totally fifty times of the test sounds, which varied in duration each 2 msec difference between 982 and 1000 msec and were provided in random manner. Therefore, sound of each duration was given 5 times. The notch [= (T-t) x 2] of the test sounds recognized by the patients was regarded as time gap. Fifty percent discrimination thresholds, which were indicated by the gap times of the test sounds half identified, were obtained as the index of the temporal auditory acuity. Following the above test, performance of the HA was investigated by use of the same procedure. The results indicated that the temporal auditory acuities of the MEI were superior to those of the HA at 500 Hz (P less than 0.01) and 2000 Hz (P less than 0.001). When the intensity of the test sound at 2000 Hz decreased from 70 dBSPL to 60 or 50 dBSPL, the temporal auditory acuities of the MEI and the HA were almost depreciated together with consistent difference in the test of 6 patients (P less than 0.01, 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[Audiological evaluation of the middle ear implant--speech discrimination under noise circumstances].

Speech discrimination scores under noise circumstances were studied by use of the middle ear implant (MEI) and the conventional hearing aid (HA, HA-33, RION, Co, Ltd). The studies were performed in 10 patients implanted with the MEI and in 12 adult volunteers with normal hearing as a control. The tests were carried out using Japanese monosyllabic lists from 57S-speech discrimination test list as a test sound and multi-talker noise as a noise source. A speaker was placed in front of a subject in one meter apart. Sound characteristics of HA were adjusted as far as possible to those of the MEI by use of a sound equalizer. The intensity of speech sound pressure was adjusted at 65dB SPL, while that of the noise was changed to 65, 70 and 75dB SPL in the position of patients. Audiological evaluation of the MEI, the HA and control obtained by percentages of correct answers to 50 words in speech discrimination test with and without noise (65, 70, 75dB SPL). When the test was performed without noise, speech discrimination scores by the MEI and the HA were either 96.8 +/- 3.6% and 94.8 +/- 4.1%. However, under noise circumstances (65dB SPL) that by both devices were either 81.6 +/- 9.1% and 66.8 +/- 10.6% (P less than 0.001). When the intensity of the noise increased to 70 and 75dB SPL, speech discrimination scores by both devices deprecated together with consistent difference (P less than 0.01). Moreover speech discrimination scores by the MEI were almost same as control.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

[Influence of tonsillar hypertrophy to school-life of children].

The authors examined degree of facial tonsillar hypertrophy for 7190 pupils of elementary schools in nine different areas in Japan. The frequency of the third degree of tonsillar hypertrophy, based on Mackenzie's criteria, decreased gradually from 6.9% of the first-year pupils to 2.9% of the sixth-year pupils with a mean of 4.8%. We also studied the relation between the degree of tonsillar hypertrophy of each pupil and the reply to the questionnaire from his or her teacher regarding various aspects of his or her school-life. The third degree of tonsillar hypertrophy of each pupil and the reply to the questionnaire from his or her teacher regarding various aspects of his or her school-life. The third degree of tonsillar hypertrophy seemed to affect school-life of pupils. For example, the frequency of pupils whose speech can be clearly recognized, was less in pupils with the third degree of tonsillar hypertrophy than in pupils without any tonsillar hypertrophy. Pupils of higher grades with the third degree of tonsillar hypertrophy were classified into two groups. One was the pupils whose school-life was not altered by tonsillar hypertrophy. The other was the pupils who were often absent from school due to chronic or acute tonsillar inflammation.

Child↗

PubMed1990

Present status and outlook of the implantable hearing aid.

An implantable hearing aid (IHA), in which the direct driving of the stapes by a ceramic vibrator is a fundamental mechanism, was applied to 24 patients with mixed hearing loss of varying degree due to chronic otitis media. The instrument used in the present study was a partial IHA, in which only the vibrator and secondary coil were implanted and the remaining components were packed in a unit to be located behind the auricle. All the patients reported that quality of sound provided by the IHA was natural, clear, and intelligible without causing fatigue with long use. Speech discrimination tests conducted under conditions with background noise demonstrated that speech perception with the partial IHA was superior to that with a conventional hearing aid. These advantages may be ascribed to the direct oscillation of the stapes by the piezoelectric element.

Adult↗

PubMed1989

A theoretical method for distinguishing between soluble and membrane proteins.

A method for distinguishing between membrane and soluble proteins in an amino acid sequence was developed, using only two parameters associated with the hydrophobicity: the average hydrophobicity and the power spectral density of period longer than 30 residues. The power spectral density was calculated by a maximum entropy method of Fourier transformation. Membrane proteins could be distinguished from soluble proteins with a distinction rate as high as 97%. This fact strongly suggests that the morphology of proteins, i.e., membrane or soluble forms, is determined thermodynamically through the hydrophobicity of polypeptides.

Amino Acid Sequence↗

PubMed1989

Veratridine-induced phosphorylation and activation of tyrosine hydroxylase, and synthesis of catecholamines in cultured bovine adrenal medullary cells.

The mechanism of the synthesis of catecholamines by veratridine was studied in cultured bovine adrenal medullary cells. (1) Veratridine increased the phosphorylation and activity of tyrosine hydroxylase as well as the synthesis of [14C]catecholamines from [14C]tyrosine, all of which were inhibited by tetrodotoxin. Veratridine-induced activation of tyrosine hydroxylase and synthesis of [14C]catecholamines were reduced in 20 mmol/l extracellular Na+ or in Ca2+-free medium. (2) 12-O-Tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C, increased the synthesis of [14C]catecholamines. In the presence of TPA, veratridine did not produce any additional increase in [14C]catecholamine synthesis. In protein kinase C-deficient cells which were prepared by pretreatment with 1 mumol/l TPA for 24 h, TPA failed to increase [14C]catecholamine synthesis and veratridine-induced [14C]catecholamine synthesis was suppressed by 50%. (3) Polymyxin B, an inhibitor of protein kinase C and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), an inhibitor of calmodulin, inhibited veratridine-stimulated synthesis of [14C]catecholamines as well as veratridine-induced influx of 22Na+ and 45Ca2+ with similar potencies. (4) In digitonin-permeabilized cells, polymyxin B attenuated the activation of tyrosine hydroxylase caused by Ca2+. These results suggest that veratridine-induced synthesis of catecholamines and activation of tyrosine hydroxylase were mediated by Ca2+-dependent phosphorylation of this enzyme, and protein kinase C may be responsible, at least in part, for this process.

Adrenal Medulla↗

PubMed1989

cis-unsaturated fatty acids stimulate catecholamine secretion, tyrosine hydroxylase and protein kinase C in adrenal medullary cells.

In digitonin-permeabilized bovine adrenal medullary cells, arachidonic acid and oleic acid, the cis-unsaturated fatty acids, enhanced Ca2+-induced secretion of catecholamines, whereas elaidic acid, a trans-unsaturated fatty acid and stearic acid, a saturated fatty acid, had no effect. Indomethacin, an inhibitor of cyclooxygenase and nordihydroguaiaretic acid, an inhibitor of lipoxygenase, failed to inhibit the stimulatory effect of arachidonic acid. Stimulation of catecholamine secretion by arachidonic acid was abolished by the removal of adenosine 5'-triphosphate and Mg2+ from the incubation medium. Pretreatment of the cells with phorbol 12-myristate 13-acetate, an activator of protein kinase C, enhanced Ca2+-induced catecholamine secretion. In cells pretreated with phorbol 12-myristate 13-acetate, the stimulatory effect of arachidonic acid on Ca2+-induced catecholamine secretion was greatly reduced. In digitonin-permeabilized cells, arachidonic acid and oleic acid enhanced Ca2+-induced activation of tyrosine hydroxylase in the presence of adenosine 5'-triphosphate and Mg2+, whereas elaidic acid and stearic acid did not activate the enzyme. In a soluble fraction of adrenal medullary cells, 32P incorporation to histone by protein kinase C was increased by arachidonic acid and oleic acid, but not by elaidic acid and stearic acid. These results suggest that cis-unsaturated fatty acids modulate Ca2+-induced catecholamine secretion and tyrosine hydroxylase activity by activation of protein kinase C in adrenal medullary cells.

Adenosine Triphosphate↗

PubMed1989

High-affinity and selectivity of neosurugatoxin for the inhibition of 22Na influx via nicotinic receptor-ion channel in cultured bovine adrenal medullary cells: comparative study with histrionicotoxin.

In cultured bovine adrenal medullary cells, neosurugatoxin and histrionicotoxin inhibited carbachol-induced influx of 22Na, 45Ca and secretion of catecholamines with IC50 of 27 nM and 3 microM, respectively. The inhibitory effects of neosurugatoxin were reversed by the increased concentrations of carbachol, whereas those of histrionicotoxin were not. Histrionicotoxin at concentrations higher than 10 microM also reduced veratridine-induced influx of 22Na, 45Ca and secretion of catecholamines, while neosurugatoxin had no effects. High K-induced 45Ca influx and catecholamine secretion were not altered by either neosurugatoxin or histrionicotoxin. The present findings suggest (1) neosurugatoxin competitively inhibits nicotinic receptor-ion channel complex at nanomolar concentrations, but has no effects on voltage-dependent Na channel and voltage-dependent Ca channel; (2) histrionicotoxin at micromolar concentrations non-competitively suppresses nicotinic receptor-ion channel complex. Higher concentrations of histrionicotoxin also interferes with voltage-dependent Na channel, but has no effect on voltage-dependent Ca channel; (3) neosurugatoxin, due to its high-affinity and selectivity, may be a useful probe for studying nicotinic receptors in nervous tissues.

Adrenal Medulla↗

PubMed1989

Carbachol-induced cosecretion of immunoreactive atrial natriuretic peptides with catecholamines from cultured bovine adrenal medullary cells.

The distribution and secretion of atrial natriuretic peptides (ANPs) were investigated in bovine adrenal medulla. (1) Cultured bovine adrenal medullary cells (2 x 10(6)/dish) contained 100.4 +/- 6.0 fmol of immunoreactive ANP (IR-ANP) and 207.3 +/- 6.6 nmol of catecholamines as epinephrine plus norepinephrine. (2) Stimulation of nicotinic but not muscarinic acetylcholine receptors caused a cosecretion of IR-ANP and catecholamines corresponding to the ratio of IR-ANP to catecholamines in cultured bovine adrenal medullary cells. (3) Carbachol-stimulated secretion of IR-ANP was dependent on the presence of extracellular Ca2+. (4) Chromaffin granules isolated from bovine adrenal medulla contained large amounts of IR-ANP and catecholamines, in the same ratio as did cultured adrenal medullary cells. (5) Reverse-phase HPLC analysis showed that both stored and secreted IR-ANP consisted of two components, which eluted at the position of ANP(99-126) or ANP(1-126). These results indicate that ANPs are stored as ANP(99-126) and ANP(1-126) in chromaffin granules, and are cosecreted in parallel with catecholamines in a Ca2+-dependent manner by the stimulation of nicotinic acetylcholine receptors.

Adrenal Medulla↗