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Biomedical subjects

N Yanagihara

Publications and source records attributed to N Yanagihara.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Fates of bone defects in the mastoid cavity studied from the findings of two-stage tympanoplasty].

The incidence and prognosis of bone defects occurring in the mastoid cavity were investigated in 205 ears of 197 patients who underwent planned two-stage tympanoplasty by the intact canal wall technique. Bone defects found at the first stage had spontaneously closed by the second stage in 43 of 62 ears at the mastoid tegmen, in 13 of 15 ears at the posterior wall of the mastoid cavity and in 2 of 17 ears at the posterior wall of the external ear canal. Twenty two ears developed bone defects at the ear canal between the first and second operations, despite the canal wall having been primarily preserved. Of the 6 ears with closure of the labyrinthine fistula using temporalis fascia at the first stage, the defects were obliterated with regenerated bone in 5 ears at the second stage. Bone defects at the facial canal were recognized in 67 ears at the first stage, 21 of which were no longer seen at the second stage.

Adolescent↗
PubMed1996

[Clinical features and prognosis of facial palsy and hearing loss in patients with Ramsay Hunt syndrome].

Clinical studies were performed on 325 patients with Ramsay Hunt syndrome who were treated in the Facial Nerve Clinic at Ehime University Hospital between 1976 and 1995. The clinical manifestations of Ramsay Hunt syndrome were various. Three major symptoms, auricular vesicles, facial paralysis and vestibulo-cochlear dysfunction, were found in 57.6% of the patients although these symptoms did not always appear simultaneously. Auricular vesicles appeared before (19.3%), during (46.5%), or after (34.2%) the onset of facial paralysis. Hearing loss was observed subjectively in only 20% but objectively in 48.2% of the patients. Hearing loss appeared before (34.3%), during (34.3%), or after (31.3%) the onset of facial paralysis. Complete recovery from facial paralysis was achieved in 52.4% of the patients. Good recovery of the facial nerve function was achieved in patients who had zoster vesicles or vestibulo-cochlear dysfunction preceding the development of facial paralysis. Complete recovery of hearing was also achieved in 45.4% of the patients, and the recovery was better in patients having light hearing loss, less than 35dB. The patients younger than 16 years old showed better recovery from both facial paralysis and hearing loss than the patients older than 60 years. Glossopharyngeal nerve or vagal nerve paralysis concomitant with facial paralysis was found in 8 (2.5%) patients. The outcome of glossopharyngeal nerve paralysis was good but that of the vagal nerve was poor.

Adolescent↗
PubMed1996

[Clinical studies on acute otitis media in infants less than one year old].

Epidemiological and bacteriological studies were made on 164 infants less than 1 year old with acute otitis media (OMA) treated at the Department of Otorhinolaryngology, Matsuyama Red Cross Hospital between January 1991 and December 1993. The patients consisted of 101 males (61.6%) and 63 females (38.4%). Compared with the general population in Matsuyama city, the preponderance of male patients with OMA is statistically significant at the level of P = 0.05. In infants less than 1 year old males are likely to be more susceptible to OMA than females. One hundred and four patients among the 164 (63.4%) were referred by pediatricians. Fever was the most common symptom (57.9%) and the next was otorrhea (19.5%). Between the patients younger than 6 months (younger group) and those 6 months old or older (older group) there were epidemiological differences which were statistically significant at the level of P = 0.05. The older group contained 128 patients (78.0%) and the younger group 36 (22.0%). The difference in incidence between the two groups indicates that infants 6 months old or older are more susceptible to OMA than those younger than 6 months. In the older group 76.6% of the patients had bilateral OMA, while in 38.9% of those in the younger group the OMA was bilateral. In infants 6 months old or older bilateral involvement and, in contrast, in infants younger than 6 months unilateral involvement was more frequent. The period needed to cure OMA was confirmed for 179 ears of 106 patients. For 80 (44.7%) of the 179 ears the period extended beyond 4 weeks. Seventy-five of the 80 ears were those of patients in the older group. OMA in the older group tended to be more resistant to treatment. The middle ear secretion of 117 ears was examined bacteriologically. Specimens were collected from middle ear effusion of 99 ears following myringotomy and from otorrhea in 18 ears. Cultures of 68 specimens were positive for one species of bacteria and 13 cultures yielded two species. Streptococcus pneumoniae, Staphylococcus epidermidis and Haemophilus influenzae were the three most common microorganisms in middle ear effusion. But it was considered that S. spidermidis was not pathogenic and was a result of contamination. In otorrhea S. aureus was frequently found. No difference in the results of bacteriological study was noted between the two groups. Transplacental IgG1 and IgG2 antibodies to S. pneumoniae and H. influenzae are known to decrease after birth and their serum levels are lowest between ages 6 months and 1 year. Then the serum levels of the immunoglobulins increase gradually with active production until age 4 years. The incidence and period of restitution of OMA in infants less than 1 year old in the present study seem to reflect the above Change in the serum levels of IgG1 and IgG2 mentioned. Based on the above results emphasis is placed on close cooperation between the otolaryngologist and the pediatrician in the treatment of OMA in an infant less than 1 year old. Particularly careful follow-up is important in patients in the older age group because they tend to be more susceptible to OMA and the disease is more resistant to treatment.

Acute Disease↗
PubMed1996

The involvement of polyamines in the proliferation of cultured retinal pigment epithelial cells.

PURPOSE: To investigate the involvement of polyamines (putrescine, spermidine, and spermine) in the proliferation of retinal pigment epithelium (RPE) using cultured bovine RPE cells. METHODS: The polyamine content and the activities of rate-limiting enzymes in polyamine biosynthesis (ornithine decarboxylase [ODC] and S-adenosylmethionine decarboxylase [SAMDC]) and in polyamine biodegradation (spermidine spermine N1-acetyltransferase [SAT]) were measured after proliferative stimulation by 10% fetal calf serum (FCS). DNA synthesis was determined by [3H]thymidine incorporation into the acid-insoluble fraction after the addition of an inhibitor of ODC (alpha-difluoromethylornithine [DFMO]) or SAMDC (methylglyoxal bis[guanylhydrazone] [MGBG]). The effects of exogenous polyamines on DNA synthesis after the additions of inhibitors also were determined. RESULTS: ODC and SAMDC activities were elevated after stimulation by FCS and reached their peaks 16 hours and 4 hours, respectively, after the addition of FCS. SAT activity was not increased. Polyamine content was increased significantly after stimulation by FCS. DFMO did not inhibit DNA synthesis induced by FCS, and only putrescine content was decreased significantly among polyamines. However, MGBG inhibited DNA synthesis in a dose-dependent manner, and the amounts of spermidine and spermine were decreased significantly. Exogenous polyamines, especially spermine, restored MGBG-induced inhibition of DNA synthesis. CONCLUSIONS: Polyamines are essential for the proliferation of cultured bovine RPE cells. These data suggest that, of the polyamines, spermine has the greatest effect on DNA synthesis although other polyamines can substitute for spermine at higher concentrations with similar results. As for polyamine metabolism in RPE proliferation, it is possible that SAMDC is the key enzyme rather than ODC.

Acetyltransferases↗
PubMed1996

Inhibition by protamine of catecholamine secretion and ion influxes in bovine adrenal medullary cells in culture.

To elucidate the mechanism of protamine-induced hypotension, we examined the effects of protamine on catecholamine secretion in bovine adrenal medullary cells and on the serum norepinephrine in the rat. 1) in bovine adrenal medullary cells in culture, protamine at concentrations of 10 to 100 micrograms/ml inhibited catecholamine secretion stimulated by carbachol. The inhibitory effect of protamine was diminished by heparin at concentrations of 3.5 to 14 U/ml. Protamine suppressed carbachol-stimulated 22Na+ influx and 45Ca++2 influx at a concentration similar to that which inhibited catecholamine secretion. Protamine (10-100 micrograms/ml) also inhibited veratridine-induced 22Na+ influx and 45Ca++ influx and 56 mM K(+)-evoked 45Ca++ influx. The inhibition of these ion influxes by protamine was closely correlated with that of catecholamine secretion. 2) In rats, i.v. administration of protamine (10 mg/kg) attenuated the arterial blood pressure and the serum norepinephrine. There was a high correlation (r = 0.96) between the serum norepinephrine and the arterial blood pressure in protaminetreated rats. Furthermore, pretreatment with heparin (1000 U/kg) abolished the protamine-induced decreases in arterial blood pressure and serum norepinephrine. Because protamine seems to inhibit catecholamine secretion by interfering with Na+ influx and Ca++ influx to adrenal medullary cells, the protamine-induced hypotension may be, at least in part, due to inhibition of norepinephrine release and ion channel activities of sympathetic nerve terminals in rats.

Adrenal Medulla↗
PubMed1995

Inhibition by carbamazepine of various ion channels-mediated catecholamine secretion in cultured bovine adrenal medullary cells.

The effects of carbamazepine (CBZ) on 22Na+ influx, 45Ca2- influx, catecholamine secretion and cyclic GMP production were examined in cultured bovine adrenal medullary cells. 1) CBZ (40-120 mumol/l) inhibited 22Na+ influx evoked by carbachol in a concentration-dependent manner. CBZ inhibited carbachol-evoked 45Ca2- influx and catecholamine secretion at concentrations similar to those which suppressed 22Na+ influx. 2) CBZ (4-120 mumol/l) inhibited veratridine-induced 22Na+ influx, 45Ca2+ influx and catecholamine secretion. 3) CBZ (12 or 40-120 mumol/l) suppressed 56 mmol/l K(+)-evoked 45Ca2+ influx and catecholamine secretion, respectively. 4) Combination of CBZ with nitrendipine or omega-agatoxin-IVA produced further inhibition of 56 mmol/l K(+)-evoked 45Ca2+ influx and catecholamine secretion, compared to the effect of CBZ alone, whereas CBZ plus omega-conotoxin-GVIA did not produce any further inhibition. 5) CBZ (40 mumol/l) attenuated the production of cyclic GMP caused by muscarine. These results suggest that CBZ at therapeutic concentrations (16-48 mumol/l; 4-12 micrograms/ml) inhibits catecholamine secretion by interfering with nicotinic acetylcholine receptor-associated ion channels, voltage-dependent Na+ channels and N-type voltage-dependent Ca2+ channels, and may have an antimuscarinic effect in adrenal medullary cells.

Adrenal Medulla↗
PubMed1995

Stimulatory effect of interleukin-1 alpha on proliferation through a Ca2+/calmodulin-dependent pathway of a human thyroid carcinoma cell line, NIM 1.

NIM 1 cells, a human thyroid cell line established from a patient with thyroid papillary adenocarcinoma, produce cytokines such as interleukin-1 alpha (IL-1 alpha) and granulocyte-colony stimulating factor. In the present study, we investigated the signal transduction pathway in the proliferation of NIM 1 cells evoked by IL-1 alpha. Incubation of NIM 1 cells with IL-1 alpha for 48 h increased the incorporation of 3H-thymidine (3H-TdR). The stimulatory effect of IL-1 alpha was evident at 0.01 ng/ml and the maximal effect was seen at 10 ng/ml. IL-1 alpha evoked an influx of 45Ca into NIM 1 cells within 3 min in a concentration-dependent manner (0.01-1 ng/ml). These stimulatory effects of IL-1 alpha on both 3H-TdR incorporation and 45Ca influx were similarly inhibited by nicardipine, an inhibitor of voltage-dependent Ca2+ channels, in a concentration-dependent manner (10-1000 nM). The stimulatory effect of IL-1 alpha on 3H-TdR incorporation was inhibited by N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), an antagonist of calmodulin, but not by 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H-7), an inhibitor of protein kinase C. While the culture medium initially contained 0.75 mM Ca2+, inhibition of 3H-TdR incorporation by nicardipine and W-7 under these baseline conditions was also recognized. These results suggest that IL-1 alpha stimulates cell proliferation through a Ca2+/calmodulin-dependent pathway in NIM 1 cells.

Biological Transport↗
PubMed1995

Facial nerve paralysis induced by herpes simplex virus in mice: an animal model of acute and transient facial paralysis.

We have been the first to succeed in producing an acute and transient facial paralysis simulating Bell's palsy, by inoculating herpes simplex virus into the auricles or tongues of mice. The KOS strain of the virus was injected into the auricle of 104 mice and the anterior two thirds of the tongue in 30 mice. Facial paralysis developed between 6 and 9 days after virus inoculation, continued for 3 to 7 days, and then recovered spontaneously. The animals were painlessly sacrificed between 6 and 20 days after inoculation for histopathologic and immunocytochemical study. Histopathologically, severe nerve swelling, inflammatory cell infiltration, and vacuolar degeneration were manifested in the affected facial nerve and nuclei. Herpes simplex virus antigens were also detected in the facial nerve, geniculate ganglion, and facial nerve nucleus. The pathophysiologic mechanisms of the facial paralysis are discussed in light of the histopathologic findings, in association with the causation of Bell's palsy.

Animals↗
PubMed1995

Effect of cAMP-dependent protein kinase on catecholamine secretion from bovine adrenal chromaffin cells.

We examined the role of cAMP-dependent protein kinase in Ca(2+)-elicited catecholamine secretion from bovine adrenal chromaffin cells. When the digitonin-treated cells were incubated with the catalytic subunit of cAMP-dependent protein kinase, the secretion of catecholamines from the cells occurred in the absence of Ca2+. The effect of the catalytic subunit was dependent on its activity (50-100 units/ml) and the presence of ATP-Mg2+ in the incubation medium. However, incubation of the cells with the regulatory subunit of cAMP-dependent protein kinase did not affect the secretion. Ca2+ (43 nM-10 microM) also increased the secretion, which was ATP-Mg(2+)-dependent. The catalytic subunit (25-200 units/ml) enhanced the Ca(2+)-evoked secretion at the suboptimal but not optimal Ca2+ concentration, which induced maximal secretion. A potent synthetic peptide inhibitor of cAMP-dependent protein kinase abolished the catalytic subunit-induced secretion, but not the Ca(2+)-evoked secretion. On the other hand, K-252a, a potent inhibitor of protein kinases, inhibited both the catalytic subunit-induced and the Ca(2+)-evoked secretion, but not KT5823, a much less potent inhibitor of protein kinases. These results strongly suggest that the catalytic subunit of cAMP-dependent protein kinase produces the secretion of catecholamines via protein phosphorylation. The results further suggest that the cAMP-dependent protein kinase does not participate in an intrinsic process of Ca(2+)-elicited secretion but it may act as a modulator.

Adrenal Cortex↗
PubMed1995

Herpetic vestibular neuritis: an experimental study.

An animal model of vestibular neuritis was developed by inoculating herpes simplex virus type 1 (HSV-1) into the auricle of mice. Postural deviation was observed in 5 of 99 mice at 6 to 8 days after inoculation. Following evaluation of the vestibular function, the animals were sacrificed and the vestibular nerves examined for histopathology and immunohistochemically. All mice developed postural deviation, presented as abnormal behaviour; they could not perform various vestibular tasks, such as gait, traversing a narrow path, climbing a rope, negative geotaxis, grasping a rod, and swimming. Degeneration of Scarpa's ganglion was observed in 4 of 5 mice that developed postural deviation, while HSV-1 antigens were found in 2 of them. No such histological findings were seen in animals with normal vestibular function.

Animals↗
PubMed1995

[Dilemma in surgical treatment of petrous cholesteatoma].

Surgical treatment of petrous cholesteatoma that involves the petrous pyramid and extends beyond the internal auditory canal is often difficult because of the site and extent of the cholesteatoma. Various problems pertaining to the operation are discussed from our experience with fourteen patients who underwent surgery in our hospital. When accompanied with otorrhea, the middle ear was eradicated by radical mastoidectomy before total removal of the cholesteatoma in order to avoid intracranial infection. Staging operation was conducted in 6 patients in which otorrhea could not be stopped by conservative treatment. The surgical approach was translabyrinthine in 10 patients, middle cranial fossa plus transmastoid in 2, and a combination of these methods in 2. The postoperative large cavity was totally exteriorized in 5 cases in which eradication of the cholesteatoma was deemed too risky, although the exposed internal auditory canal and the denuded dura were supplemented locally. In the other 9 cases, the cavity was obliterated with abdominal fat and/or muscle flap. Facial nerve palsy was present preoperatively in 11 patients. They were treated by decompression in 7 cases, nerve-anastomosis in 2 and nerve grafting in one. In one patient, atrophy of the nerve was too severe to perform nerve grafting. Plastic surgery, such as suspension of the eyelid and masseter muscle transfer, was additionally carried out in 6 of the above patients. Postoperative follow-up study with CT and MRI is very important. In 3 of our cases, the cholesteatoma recurred and the reoperation was needed.

Adult↗
PubMed1995

[Middle fossa acoustic neuroma surgery--indications and predictive factors for hearing restoration].

Between June 1990 and May 1993, 17 acoustic tumors were removed by the middle cranial fossa approach with attempted hearing preservation. Measurable hearing was restored in 13 patients (76.5%) and useful hearing (PTA < 50 dB, SDS > 50%) in 10 patients (58.8%). In addition, significant hearing improvement, greater than 10 dB in pure-tone average, was noted in 6 patients (35.3%). In the hearing improvement group, useful hearing was restored after tumor resection in two patients with poor preoperative hearing. These six patients with hearing improvement exhibited several findings in common: smaller tumors, sudden deterioration of hearing, trough type of audiogram, inferior vestubular nerve origin and short duration of hearing loss before surgery. Such signs suggested favorable preoperative prognostic factors for potential postoperative hearing improvement. Because there was no significant difference between postoperative facial nerve outcome in the middle cranial fossa approach and the translabyrinithine approach in our series of small tumors, we recommend the use of the middle cranial fossa approach for hearing preservation in patients with small tumors, even when their hearing is poor preoperatively.

Adult↗
PubMed1995

[Operative results in fourteen cases of paranasal sinus and anterior cranial fossa lesions surgically treated by an extended transbasal approach].

We describe the outcomes and complications of 14 patients with paranasal sinus and anterior cranial fossa lesions surgically treated by an extended transbasal approach, originally described by Kawakami, in our department. They were 10 patients with malignant tumors, 2 with benign tumors, and 2 with inflammatory diseases. A bifrontal craniotomy was performed using a high coronal skin incision, and the orbital rim and roof were removed after the dissection of the dura mater from the anterior skull base. Transcranial resection of the tumor was performed, and assisted by transnasal and transmaxillar resection using a nasal endoscope. Reconstruction of the anterior skull base was performed with the fasica lata and galeopericranial flap in all cases, temporal musculo-pericranial flap in 3 and free bone flap from the cranial convex in 3. Among 10 patients with malignant tumors (malignant melanoma; 4, squamous cell carcinoma; 2 adenocarcinoma; 1, malignant plemorphic adenoma; 1, chondrosarcoma; 1, and neuroblastoma; 1), total removal was performed in 5 patients and subtotal removal in 5 patients. Though local recurrence of the tumor was recognized in 6 patients, only one underwent additional surgery. Eight patients survived, and 2 patients died of systemic metastasis of the tumor and complications due to liquorrhea. Seven patients obtained a good quality of life, and the mean survival period in 8 patients still living was 27 months after the first surgery. In 2 patients with benign tumors (chordoma and osteoma), partial and total removal was performed. The patient with chordoma was operated on several times by this approach and the transoral approach, respectively. Each had a good postoperative course.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Partially implantable hearing aid using piezoelectric ceramic ossicular vibrator. Results of the implant operation and assessment of the hearing afforded by the device.

The aim of designing an implantable hearing aid (IHA) is to compensate for some of the disadvantages of conventional hearing aids. The IHA described in this article is a direct oscillation type in which the piezoelectric ceramic ossicular vibrator coupled directly to the stapes transmits sound signals to the perilymph effectively. This type of IHA can give a better fidelity of sound perception than a conventional hearing aid.

Adult↗
PubMed1995

[The detection of anti-cerebellar antibody western blot analysis in serum from a patient with Miller Fisher syndrome].

We here report a case of Miller Fisher syndrome (MFS) in which serum anti-cerebellar antibody was detected by Western blot analysis. The 32-year-old male studied suffered from diplopia, gait ataxia and sensory disturbance in the distal portion of the upper limbs preceded by cold-like symptoms. Neurological examination on admission revealed that he had external ophthalmoplegia with bilateral ptosis, cerebellar ataxia and areflexia. A cerebrospinal fluid examination showed albuminocytologic dissociation with a protein concentration of 60 mg/dl. Brain CT and MRI showed no significant abnormalities. The patient was diagnosed as MFS, and treated it with two sessions of immunoadsorption plasmapheresis (IAPP). After receiving IAPP therapy, the patient's neurological symptoms and signs were improved. Western blot analysis showed the existence of antibody directed against mouse cerebellum but not against mouse cerebrum, brain stem, and spinal cord in his serum, the level of which was decreased after the IAPP therapy. Serum anti-GQ1b antibody was also elevated. As far as we are aware, there have been no reports showing the existence of anti-cerebellar antibodies detected by Western blot analysis. Though the pathogenesis of MFS remains unclear, our findings suggest that anti-cerebellar antibody detected by Western blot analysis may be caused by cerebellar ataxia in MFS.

Adult↗
PubMed1994

Stimulatory effect of IL-1 beta on catecholamine secretion from cultured bovine adrenal medullary cells.

We investigated the effect of recombinant human interleukin-1 beta (IL-1 beta) on catecholamine secretion from cultured bovine adrenal medullary cells. Treatment of cultured cells with IL-1 beta (10 ng/ml) for 24 hr caused an increase in accumulation of catecholamines in the cultured medium. The accumulation of catecholamines stimulated by IL-1 beta was observed in time (4-48 hr)- and concentration (3-30 ng/ml)-dependent manners. The stimulatory effect of IL-1 beta (10 ng/ml) was completely inhibited by recombinant human IL-1 receptor antagonist (1 microgram/ml). IL-1 beta had little effect on [3H]norepinephrine uptake to cultured cells. These results suggest that IL-1 beta stimulates catecholamine secretion through activation of IL-1 receptors in adrenal medullary cells.

Adrenal Medulla↗