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Biomedical subjects

N Yanagihara

Publications and source records attributed to N Yanagihara.

At least 19 recordsLinked to original sources
PubMed1996

Bell palsy and herpes simplex virus: identification of viral DNA in endoneurial fluid and muscle.

OBJECTIVE: To determine whether herpes simplex virus type 1 (HSV-1) causes Bell palsy. DESIGN: Prospective study. SETTING: University inpatient service. PATIENTS: 14 patients with Bell palsy, 9 patients with the Ramsay-Hunt syndrome, and 12 other controls. MEASUREMENTS: Viral genomes of HSV-1, varicella-zoster virus, and Epstein-Barr virus were analyzed in clinical samples of facial nerve endoneurial fluid and posterior auricular muscle using polymerase chain reaction (PCR) followed by hybridization with Southern blot analysis. RESULTS: Herpes simplex virus type 1 genomes were detected in 11 of 14 patients (79%) with Bell palsy but not in patients with the Ramsay-Hunt syndrome or in other controls. The nucleotide sequences of the PCR fragments were identical to those of the HSV-1 genome. CONCLUSIONS: Herpes simplex virus type 1 is the major etiologic agent in Bell palsy.

Adult↗
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↗
PubMed1994

Differential up-regulation of voltage-dependent Na+ channels induced by phenytoin in brains of genetically seizure-susceptible (E1) and control (ddY) mice.

We investigated the effect of in vivo administration of an antiepileptic drug, phenytoin, on the saxitoxin binding capacity of receptor site 1 of the Na+ channel alpha-subunit, and the expression activity of the channel messenger RNA in epileptic El mouse brains, as compared with parental ddY mice. Subchronic treatment with phenytoin (25 mg/kg per day) for 14 days increased the [3H]saxitoxin binding to brain-derived synaptic membranes of both El and control ddY mice in a time dependent manner. This increase plateaued at 21 +/- 4% in El mice and 28 +/- 3% in ddY control mice after administration of phenytoin for seven days. After cessation of treatment with phenytoin, [3H]saxitoxin binding capacity returned to the basal level within two weeks in both ddY and El brains. Scatchard plot analysis revealed that the phenytoin treatment caused a 20-30% increase in maximum binding capacity of [3H]saxitoxin binding without any change in equilibrium dissociation constant in the brain cortical synaptic membranes of both epileptic El and control ddY mice. A single injection of phenytoin (25 mg/kg) elevated the level of Na+ channel messenger RNA within 1 h in ddY mouse brains. The increase in Na+ channel messenger RNA reached a peak (about 80% increase) after 5 h of phenytoin administration in a concentration-dependent manner (6.25-50 mg/kg). On the other hand, in El mouse brains, Na+ channel messenger RNA was not elevated until more than 5 h after phenytoin injection, and was increased by only about 33%.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphibian Proteins↗
PubMed1994

The receptor, metabolism and effects of androgen in osteoblastic MC3T3-E1 cells.

We investigated the androgen receptor (AR), metabolism and effects of androgens in osteoblastic MC3T3-E1 cells. AR was proved as a transcript of a 10-kb mRNA and as a 110-kDa protein. An immunocytochemical study showed that AR was located mainly in the nuclei. Specific binding of [3H]DHT was observed in both the nuclear and cytosol fractions. MC3T3-E1 cells possessed approximately 1190 binding sites per cell and most of the sites (1150 sites) situated in the nucleus. The apparent Kd value in the nuclear fraction was 1.35 nM for [3H]DHT binding, and it was similar to that for [3H]testosterone. In the competition analysis, there was not much difference in the displacement of the [3H]DHT binding from AR between the addition of radioinert DHT and testosterone. In studies of 5 alpha-reductase activity and aromatase activity of the cells, both activities were lower than the respective values in classical androgen target tissues. Androgens stimulated the incorporation of [3H]thymidine into the cell, and DHT and testosterone had a similar potency on the cell proliferation. Thus, these results suggest testosterone itself acts mainly on the osteoblasts without conversion to DHT.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1994

Regeneration of facial nerve after hypoglossal facial anastomosis: an animal study.

Hypoglossal-facial nerve anastomosis was carried out in 20 adult guinea pigs. Electromyographic responses of orbicularis oculi muscle evoked by blink reflex were recorded 2, 4, and 6 months after surgery. Then the anastomotic site was reopened, and a segment of buccal branch and the anastomotic trunk were resected for detailed histologic study. Regenerated axons were counted and the cross-sectional area of axons and fasciculi was measured. Data obtained from both blink reflex measurement and histologic study demonstrate a good quality of regeneration of the facial nerve from the hypoglossal nerve completed 6 months after the operation. In addition a new nerve bundle was regenerated from the proximal stump of the facial nerve connecting to the anastomotic site in 80% of the animals. Postoperative change in innervation pattern of the facial nerve was also illustrated.

Anastomosis, Surgical↗
PubMed1994

Experimental cholesteatomas arising from autologous free skin grafting in the middle ear cavity.

An autologous free skin graft taken from the upper or the lower external ear canal or the auricle was implanted in the otic bulla of 28 guinea pigs. An epidermal cyst simulating middle ear cholesteatoma was successfully produced in 25 (89.3%) animals 8 weeks after grafting. Using this model, the histological reaction of middle ear granulation tissue to the debris was studied. Cysts originated from the auricular skin showed the strongest activity with regard to growth rate, amount of debris produced, and inflammatory reaction to the exposed debris. We conclude that the exposed debris plays an important role in chronic granulomatous inflammation in association with cholesteatoma.

Animals↗
PubMed1994

Change in facial nerve innervation following hypoglossal-facial anastomosis. An animal study.

Hypoglossal-facial nerve anastomosis was carried out in 20 adult guinea pigs. Horseradish peroxidase (HRP) was applied to the buccal branch of the facial nerve at intervals of 2, 4 and 6 months after the anastomosis operation. HRP labeled neurons and the number of regenerated axons in the buccal branch were counted to determine postoperative nerve regeneration. The number of surviving neurons in the facial and hypoglossal nuclei was also counted to determine postoperative change of these nuclei. Following anastomosis, 97% of the hypoglossal neurons remained surviving, while the facial neurons underwent pronounced degeneration of 65% survival ratio at 2 months and 37% at 6 months after the anastomosis operation. In 80% of the animals, a new nerve bundle regenerated from the proximal stump of the facial nerve to the anastomotic trunk. A linear increase of HRP-labeled neurons in the facial and hypoglossal nuclei paralleled the increase of the axons in the buccal branch. The HRP-labeled neurons in the facial nucleus were demonstrated to have direct connection with the newly formed bundle and the facial mimetic muscles were dually innervated by both the hypoglossal and facial nerves. Although the present study design might not fully represent the clinical situation, possible advantages of hypoglossal-facial nerve anastomosis are discussed from the view of nerve regeneration.

Anastomosis, Surgical↗
PubMed1994

Effects of combined rupture of Reissner's membrane and the round window on hearing in the guinea pig.

Hearing impairment caused by sequential rupture of Reissner's membrane and the round window was investigated in guinea pigs to determine if the double-membrane break can cause acute profound sensorineural hearing loss. Reissner's membrane was lacerated through the stria vascularis at one of the turns of the cochlea, followed by rupture of the round window to create leakage of the perilymph. Action potentials (APs) to tone pip stimuli were recorded from the Fallopian canal electrode before and 90 min after these procedures. The results showed that the ears with the double-membrane break at the second turn showed a larger increase in AP threshold than did the control ears with only round window rupture. However, this was not seen when Reissner's membrane had been ruptured at the other turns.

Acoustic Stimulation↗
PubMed1994

Postoperative recurrence of perilymphatic fistulas.

Postoperative follow-up study of perilymphatic fistulas (PLFs) showed that recurrence of PLF was not rare and revision was sometimes needed to relieve the symptoms associated with leakage of perilymph. Of the 54 PLF patients surgically treated in our clinic, some sign or symptom of recurrence was found in 9 cases (17%). Vertigo accompanied by spontaneous or positional nystagmus was noted in all 9 cases, while only 3 complained of exacerbation of the existing hearing loss. Revision was indicated in 3 patients since they had no predisposition to spontaneous healing. Various etiological and underlying factors contributed to the incidence of recurrence. Careful operative procedures together with strict postoperative management are required for surgical treatment of PLF.

Adolescent↗
PubMed1994

Detection of human alpha-herpesvirus DNA using consensus primers and specific probes.

A simple and rapid diagnostic assay system was developed for detecting and identifying human alpha-herpesviruses, such as herpes simplex virus types 1 and 2 and varicella-zoster virus, by polymerase chain reaction. This system was based on an amplification step, using primers that bind the DNA polymerase consensus sequence of alpha-human herpesviruses, and a detection step, using non-radioactive virus-specific probes. This method could be used to amplify any human alpha-herpesviruses, and each virus-specific probe was highly specific for identification of the amplified product. This system is readily applicable for implementation in the clinical laboratory.

Cytomegalovirus↗