Biomedical subjects

Hideaki Suzuki

Publications and source records attributed to Hideaki Suzuki.

At least 37 records · Page 2Linked to original sources

PubMed2005

Assignment of the gene for porcine insulin-like growth factor binding protein 1 to chromosome 18 and detection of polymorphisms in intron 2 by PCR-RFLP.

We have obtained a partial cDNA and three BAC clones for the porcine insulin-like growth factor binding protein 1 gene (IGFBP-1). Results of fluorescence in situ and radiation hybrid (RH) mapping assigned this gene to porcine chromosome (SSC) 18q24-qter. We found two types of polymerase chain reaction-restriction-fragment-length polymorphisms (PCR-RFLP) in intron 2 by using FokI and AluI.

Animals↗

PubMed2005

Delayed-onset temporary auditory threshold shift following head blow in guinea pigs.

This study attempts to investigate the development of sensorineural hearing loss following a head blow without skull fracture in association with physiological and histopathologic changes in an experimental animal model. With the head in a freely movable position, albino guinea pigs were given a single blow to the occipital region by a head blow device. At 1, 7, and 14 days after the blow, the animals' auditory brainstem response (ABR) and cochlear microphonics (CM) were examined, and both the temporal bone and brain stem were observed by light and electron microscopy. The ABR threshold was unchanged at day 1, was significantly increased at day 7, and was fully recovered at day 14. The I-V and I-II interpeak latencies were significantly prolonged at days 1 and 7, and wave I latency was significantly prolonged at day 7 only. These latencies were recovered to normal limits at day 14. On the other hand, no significant change in CM versus the control group was observed at any point in the measurements. Histopathologically, no abnormal finding was seen at the light microscopic level. However, at the electron microscopic level, there were some injuries to the eighth nerve. At day 1, the lamellar structure of the myelin sheath was irregular, and the periaxonal space was expanded; at day 7, the myelin sheath was disintegrated. At day 14, however, these changes were partially reversed. These results suggest that sensorineural hearing loss following a head blow in this model is attributed to dysfunction of the eighth nerve rather than to cochlear impairment.

Animals↗

PubMed2005

A gamma-lactone form nafuredin, nafuredin-gamma, also inhibits helminth complex I.

Nafuredin, a delta-lactone antibiotic, is a fungal metabolite showing selective helminth NADH-fumarate reductase inhibition, and whose target had been revealed as complex I. We found that nafuredin is easily converted to nafuredin-gamma by weak alkaline treatment. The structure of nafuredin-gamma was elucidated as a gamma-lactone form of nafuredin with keto-enol tautomerism. Nafuredin-gamma shows similar complex I inhibitory activity as nafuredin, and it also possesses anthelmintic activity in vivo.

Animals↗

PubMed2005

Giant myoepithelioma of the upper lip.

Myoepithelioma is a relatively rare form of salivary gland tumor composed entirely of myoepithelial cells. This tumor was formerly considered to be a subtype of pleomorphic adenoma; however, in the latest World Health Organization classification of 1991 it is listed as an independent entity. We report herein an extremely rare case of myoepithelioma of the upper lip. A 78-year-old Japanese female presented with a huge, painless mass on her upper lip. CT and MRI revealed a 50 x 40 mm(2) well-defined ovoid tumor. A benign minor salivary gland tumor was clinically suspected, and the patient underwent complete resection of the tumor under general anesthesia. The surgical defect was immediately reconstructed using an Abbe-Estlander flap. The tumor was histopathologically diagnosed as a benign myoepithelioma of the minor salivary gland. Immunohistochemically, the tumor cells were positive for vimentin, cytokeratins, alpha-smooth muscle actin and S-100 protein, confirming the morphological diagnosis of myoepithelioma. The patient's postoperative clinical course was uneventful, and satisfactory results were obtained both functionally and esthetically. The pathology, clinical manifestations and treatment of myoepithelioma are reviewed.

Aged↗

PubMed2005

[Surveillance of industrial physicians' knowledge and concern about sleep apnea syndrome].

Sleep apnea syndrome (SAS) is a risk factor in lifestyle-related disease known to be closely associated with traffic and occupational accidents. Because of its high morbidity in middle-aged men, early diagnosis and management by industrial physicians are important. We clarified the degree of knowledge and concern about SAS among industrial physicians. We e-mailed questionnaires to 199 industrial physicians belonging to the Industrial Medical Promotion Society, and Most answered that industrial received responses from 51 (40 contracted and 11 part-time industrial physicians). physicians should participate in the management of SAS to prevent doze accidents, to control lifestyle-related diseases, to judge vocational fitness, and to lower economical expense. Fewer than 30% of physicians had conducted educational activities, and even fewer had practiced interviews and screening for SAS. Financial difficulty, lack of specialized hospitals for SAS, lack of labor, and a lack of concern among executives are major obstacles to SAS screening for employees. We concluded that, despite the concern industrial physicians, SAS is practically disregarded in their work. Cost-and time-effective screening and guidelines for employees with SAS should be established to facilitate the management of SAS by industrial physicians.

Accidents, Occupational↗

PubMed2004

A new organic superconductor beta-(meso-DMBEDT-TTF)2PF6.

A newly synthesized donor meso-DMBEDT-TTF [DMBEDT-TTF = 2-(5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene)-5,6-dihydro-5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin] afforded a superconducting salt beta-(meso-DMBEDT-TTF)2PF6, with a transition temperature at 4.3 K (onset) under a hydrostatic pressure of 4.0 kbar.

Crystallography, X-Ray↗

PubMed2004

[Rehabilitation and return-to-work after laryngectomy: the role of industrial otolaryngologists].

Rehabilitation and return-to-work are important problems for laryngectomized patients. Here, we report 2 cases of laryngectomized middle-aged men, and discuss the role of otolaryngologists from the viewpoint of an industrial physician. The first case is a 55-year-old post-office male clerk, who underwent radical and reconstructive surgery for hypopharyngeal carcinoma. He started light work following 3-month-rest at home after discharge, and fully returned to his previous work 3 years later. The second case is a 50-year-old mailman who also underwent radical and reconstructive surgery for hypopharyngeal carcinoma. He could not return to work because of the recurrence of tumor during rehabilitation. In such cases, comprehensive management including medical, mental and social supports is essential according to the occupational environment. Industrial otolaryngologists should play an important role in rehabilitation and return-to-work of laryngectomized patients.

Cervicoplasty↗

PubMed2004

Characterization of 298 ESTs from porcine back fat tissue and their assignment to the SSRH radiation hybrid map.

Following several criteria, we collected, clustered, and functionally categorized 653 expressed sequence tags (ESTs) of 5' ends from porcine back fat libraries from the >15,000 porcine ESTs collected to date. By searching the LocusLink and Mapviewer database, we knew the positions of these 653 ESTs on human chromosomes (HSAs). Sus scrofa radiation hybrid (SSRH) mapping revealed that 298 porcine EST clusters out of 653 were localized near microsatellite (MS) markers. Among these EST clusters, we could assign 182 to their porcine chromosomes (SSCs) on the SSRH map.

Adipose Tissue↗

PubMed2004

Effects of glucocorticoid receptor antagonist on CAPs threshold shift due to short-term sound exposure in guinea pigs.

OBJECTIVE: The steroid drugs are used for the standard treatment of sudden sensorineural hearing loss. However, clinical results on the effect of glucocorticoids in acoustic trauma have not yet been understood well. The effects of glucocorticoid receptor (GR) antagonist, mifepristone, on the cochlea sensitivity loss due to short-term sound exposure were studied in the guinea pig. METHODS: Mifepristone (20 mg/kg) was injected subcutaneously immediately after the noise exposure to 4 kHz pure tone of 100 or 120 dB SPL for 10 min and also at 1 day and 3 days later. Seven days after the sound exposure, the compound action potentials (CAPs) of the cochlear nerve and the 2f(1)-f(2) distortion product oto-acoustic emissions (DPOAEs) were recorded. RESULTS: No significant CAP threshold losses were observed in either mifepristone or saline administration after the exposure at 100 dB SPL. After the exposure at 120 dB SPL, administration of mifepristone elevated the CAP threshold at 5-8 kHz significantly as compared with the saline administration. The DPOAE output shifts of both saline and mifepristone groups were similar to each other. CONCLUSION: Mifepristone may influence inner hair cells (IHCs) and afferent nerve fibers beneath the IHC without having influence on outer hair cells (OHCs). It is suggested that glucocorticoid plays an important role in the improvement of hearing impairment after loud sound exposure.

Action Potentials↗

PubMed2004

Effect of salicylate on electrically evoked otoacoustic emissions elicited in the first and third turns of the guinea pig cochlea.

OBJECTIVE: Electrically evoked otoacoustic emissions (EEOAEs) are sounds emitted in the ear canal when an alternating current is delivered to the cochlea. Salicylate, which causes reversible hearing loss, decreases both the electromotility of the outer hair cells (OHCs) and the EEOAE output. The frequency response of EEOAEs is known to depend on the location of the stimulating electrode. Using electrodes placed in the first or third turn of the cochlea, we measured EEOAEs before and after salicylate administration in order to clarify the frequency range of EEOAEs from which exact information can be acquired. MATERIAL AND METHODS: A sinusoidal electrical signal (160 microA root-mean-square) at frequencies ranging from 500 Hz to 16 kHz was delivered to the first or third turn of the scala tympani of the guinea pig cochlea in order to determine EEOAEs. The EEOAE outputs were measured before and every 5 min after administration of salicylate (500 mg/kg) for 60 min. The threshold of the compound action potential (CAP) was measured before and 60 min after salicylate administration. RESULTS: CAP thresholds were reduced at frequencies ranging from 2 to 12 kHz after salicylate administration. The maximum EEOAE output recorded with the first-turn electrode was obtained at 12 kHz with a gentle slope of low cutoff, whereas the frequency response of the EEOAE recorded with the third-turn electrode demonstrated a steep dip at 2 kHz. CONCLUSION: EEOAE reduction after salicylate administration was restricted to frequencies close to that of the characteristic frequency (CF) of the electrode position. This was probably related to the fact that the EEOAE is the sum of waves from the CF of the electrode position and the stimulus frequency. In terms of studying the electromotility of OHCs, useful information obtained from EEOAEs is restricted to the narrow frequency band close to the CF of the electrode location.

Action Potentials↗

PubMed2004

Pioglitazone prevents acute liver injury induced by ethanol and lipopolysaccharide through the suppression of tumor necrosis factor-alpha.

BACKGROUND: Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), which is a ligand-dependent transcriptional factor, forms a heterodimer with retinoid X receptor (RXR) and controls many genes that are relevant to the regulation of lipid metabolism and insulin sensitization. Recent studies have shown that stimulation of PPAR-gamma inhibits the production of inflammatory cytokines in monocytes and macrophages. Alcohol and lipopolysaccharide (LPS) have already been shown to induce liver injury through the activation of many inflammatory cytokines. Thus, the activation of PPAR-gamma by its ligand may represent a potential effect causing liver injury. In this study, we investigated the effects of pioglitazone, a ligand for PPAR-gamma, on acute liver injury induced by ethanol and LPS. METHODS: Female Sprague-Dawley rats that weighed 300 g were given ethanol (5 g/kg body weight) intragastrically and received an intraperitoneal injection of LPS 24 hr later. Subsequently, pioglitazone (1 mg/kg body weight) or vehicle alone was injected intraperitoneally 10 min and 24 hr after ethanol administration. Plasma levels of aspartate transaminase and alanine aminotransferase were measured by spectrophotometer. Plasma levels of tumor necrosis factor-alpha (TNF-alpha) were also determined using an enzyme-linked immunosorbent assay. Plasma and hepatic levels of lipid peroxide were measured, and the histologic findings of the liver were examined. Reverse transcription-polymerase reaction analysis of TNF-alpha, PPAR-gamma, RXR-alpha, and beta-actin mRNA was performed. Western blot analysis using the p65 subunit of NF-kappaB was also performed. RESULTS: Pioglitazone prevented increase in plasma aspartate transaminase, alanine aminotransferase, and TNF-alpha levels but had no effect on plasma and hepatic levels of lipid peroxide. Pioglitazone also prevented hepatic inflammation and necrosis induced by ethanol and LPS. Ethanol and LPS induction of TNF-alpha mRNA in the liver was blunted by pioglitazone; however, RXR-alpha mRNA was not affected. PPAR-gamma mRNA levels were suppressed by ethanol and LPS but recaptured by pioglitazone. Western blot analysis showed that pioglitazone did not inhibit translocation of NF-kappaB to nuclei. CONCLUSION: These results suggest that pioglitazone may prevent liver injury induced by ethanol and LPS through the suppression of TNF-alpha.

Animals↗

PubMed2003

Ischemia of the intestinal mucosa during cardiopulmonary bypass.

Bacterial translocation is believed to occur during cardiopulmonary bypass (CPB) because serum endotoxin concentrations rise. Intestinal ischemia during CPB, however, has never been proven directly. The condition of the intestinal mucosa during CPB was studied by measuring serum diamine oxidase (DAO) activity, an index of intestinal ischemia. Serum DAO activity, blood lactate concentration, and the arterial ketone body ratio (AKBR) were measured intraoperatively in four successive patients who underwent aortic arch replacement by the open distal anastomosis method. DAO activity rose after restoration of blood flow to the lower half of the body, and continued to rise throughout CPB. The lactate concentration also rose, mirroring the change in DAO activity, and returned to nearly normal 12 h after the operation. The AKBR decreased during CPB, with a mean minimum vale of 0.16-0.07 immediately after the restoration of blood flow to the lower half of the body. The parallel rise in DAO activity and serum lactate concentration once blood flow to the lower half of the body was restored implies that ischemic injury to the mucosa of the small intestine occurs during CPB. The continued rise in these parameters throughout CPB is consistent with ongoing injury due to splanchnic hypoperfusion, as reflected in the decrease in the AKBR during the same period.

Aged↗

PubMed2003

An example of design optimization for high evolvability: string rewriting grammar.

As an example of the optimization of an evolutionary system design, a string rewriting system is studied. A set of rewriting rules that defines the growth of a string is experimentarily optimized in terms of maximizing the 'replicative capacity', that is the occurrence ratio of self-replicating strings. It is shown that the most optimized rule set allows many strings to self-replicate by using a special character able to copy an original string sequentially. Then, using various different rewriting rule sets, the connectivity between self-replicating strings is studied. A set of 'hyperblobs' covering the self-replicating strings is extracted and their connectivity is studied. The experimental results show that a large replicative capacity assures strong connectivity between self-replicating genotypes, making the system highly evolvable.

Algorithms↗

PubMed2003

Epithelial-myoepithelial carcinoma of the parotid gland.

We report a rare case of epithelial-myoepithelial carcinoma (EMC) of the parotid gland. A 70-year-old man presented with a 4-months-history of right-sided subauricular swelling. Computed tomographic scans revealed a well-defined mass with cystic lesion, measuring about 40 mm in diameter, in the right parotid gland. Because the tumor occupied superficial lobe, he underwent superficial parotidectomy with preservation of the facial nerve. On the basis of the histological and immunohistochemical findings, the tumor was diagnosed as EMC. His post-operative course was uneventful, and he is currently free from disease 6 months after surgery. Diagnosis, clinical behavior and treatment of EMC are reviewed from perusal of the literature.

Aged↗

PubMed2003

Orbital apex syndrome caused by sphenoethmoid mucocele.

We report a rare case of complete orbital apex syndrome due to sphenoethmoid mucocele. A 61-year-old male presented with a 3-day-history of right-sided sudden proptosis, ophthalmoplegia, and visual loss. Computed tomographic scan and magnetic resonance imaging revealed a cystic mass measuring 25-mm in diameter of the right sphenoethmoid region. At first intravenous antibiotics and corticosteroids had been given but not effective. He underwent endonasal marsupialization using endoscopy. His post-operative course was good. The eye symptoms gradually recovered, and his visual acuity completely recovered 3 months after surgery.

Ethmoid Sinus↗

PubMed2003

Surgical treatment of subperiosteal abscess of the orbit: Sendai's ten-year experience.

OBJECTIVE: One of the common complications of acute infection of the paranasal sinus is cellulitis of the orbit. This is secondary to the spread of infection through the very thin bony wall between the ethmoid sinuses and the orbit, the roof of the orbit in frontal sinusitis, and the floor of the orbit in maxillary sinusitis. When the infection does not penetrate the periorbita, it dissects under the periosteum and forms subperiosteal abscess. METHODS: We experienced 10 patients with subperiosteal abscess for 10 years from 1992 to 2002 that required surgical drainage. The age of the patients ranged from 4 to 76 years including five males and five females. RESULTS: Successful and safe drainage of the abscess with endoscopic sinus surgery was obtained in four patients while six patients required external surgery. The selection of the surgical approach depended upon the localization of abscess in the orbit. Five of the seven patients with visual disturbance resulted in a complete recovery of vision after surgery. However, there was no improvement of visual acuity in the other two patients who had already shown severe damage of vision prior to treatment. CONCLUSION: Ocular symptoms such as exophthalmos, double vision, and ptosis subsided completely in all patients. It is suggested that prompt diagnosis and surgical drainage before severe loss of visual acuity rescue or recover the vision.

Abscess↗

PubMed2003

Defibrinogenation therapy for idiopathic sudden sensorineural hearing loss in comparison with high-dose steroid therapy.

OBJECTIVE: The efficacy of defibrinogenation therapy for idiopathic sudden sensorineural hearing loss was studied in comparison with high-dose steroid therapy. MATERIAL AND METHODS: Eighty-eight consecutive patients with hearing levels > 40 dB and who had suffered hearing loss for < or = 30 days were enrolled: 40 patients for high-dose steroid therapy (PSL group) and 48 for defibrinogenation therapy (BX group). Hearing recovery was evaluated by grade assessment and by the improvement in hearing compared to the unaffected contralateral ear. RESULTS: The overall hearing outcomes of the two groups were roughly equivalent. However, with regard to patients with initial hearing levels < 80 dB, the hearing improvement rate of the BX group was significantly worse than that of the PSL group (61.2% +/- 7.3% vs 88.7% +/- 8.9%; p < 0.05), whereas in patients with initial hearing levels > or = 80 dB, the hearing outcomes did not differ between the 2 groups. Three patients in the PSL group manifested hyperglycemia while no serious side-effects were observed in the BX group. CONCLUSION: These results indicate that high-dose steroid therapy should be employed in preference to defibrinogenation therapy for patients with moderate hearing loss, whereas defibrinogenation therapy has an advantage for those with severe hearing loss, in view of its lower frequency of side-effects.

Administration, Oral↗

PubMed2003

Study of nocturnal sleep and the carryover effects of triazolam and brotizolam using neurophysiological and subjective methods.

In the present study, the effects of short-acting benzodiazepines on nocturnal sleep and the carryover effects of these drugs were studied. The study involved 10 young, healthy male subjects who had given their written informed consent to participate. Either a placebo (PLA), 0.125 mg triazolam (TRZ), 0.25 mg TRZ or 0.25 mg brotizolam (BRZ) was administered to the subjects in a double-blind crossover design by randomized allocation with a single oral administration at 23.00 h. A polysomnography (PSG) was recorded for each subject from 23.00 to 07.00 h the following day. Then, the Stanford Sleepiness Scale (SSS) and Kwansei Gakuin Sleepiness Scale (KSS) were checked between 07.55 and 08.00 h, and the sleep latency test (SLT) was performed between 08.00 and 08.20 h. Event-related potentials (ERPs) were then recorded with an oddball paradigm; the reaction time (RT) was measured simultaneously. According to the PSG, treatment with 0.25 mg TRZ resulted in a statistically significant increase in the percentage of stage 2 sleep (p < 0.05) and a reduction in the percentage of rapid eye movement sleep (p < 0.05) compared with PLA. None of the drugs had any effect on the percentage of slow-wave sleep compared with PLA. With regard to carryover effects, although none of the drugs had any effect on SSS, KSS, RT or ERPs, BRZ did cause a statistically significant decrease in sleep latency (p < 0.05) compared with PLA. TRZ (0.125 and 0.25 mg) and 0.25 mg BRZ exerted different effects on SLT. We suggest that these different effects are attributable to differences in the half-life of these hypnotics.

Adult↗