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Y Orita

Publications and source records attributed to Y Orita.

At least 19 recordsLinked to original sources
PubMed2001

Ménière's disease in childhood.

We report 3 rare cases of Ménière's disease in children. In Case 1 and 3, vertigo, hearing loss and tinnitus recovered soon after medical therapy. In Case 2, however, vertigo recurred and the hearing level on the right side markedly deteriorated. The equal-loudness contours on three-dimensional audiogram showed that right-sided aggravated hearing loss fluctuated for 4 years at middle-and low-frequencies despite medication. Finally intratympanic injection of gentamicin sulfate was performed. The patient has had no definitive spell of vertigo after gentamicin therapy. At our department, the incidence of Ménière's disease in pediatric patients with vertigo was 2.9%.

Adolescent↗
PubMed2001

Temporal bone histopathological study of Noonan syndrome.

Four temporal bone specimens, obtained from three individuals 1--6 years of age with Noonan syndrome (NS), were studied histopathologically. All four specimens were accompanied by similar inner ear abnormalities including the reduced number of spiral ganglion cells, enlarged lateral semicircular canal, and dislocated endolymphatic sac and vestibular aqueduct. The mean population of spiral ganglion cells (15,699 cells) was approximately half of those (32,978 cells) in four age-matched control cases. In addition, they had several middle ear abnormalities including the remaining mesenchyme and dehiscence of the facial canal. To our knowledge, this is the first report to describe the histopathological temporal bone findings in patients with NS. We discuss the implications of the observed abnormalities with regard to clinical issues.

Child↗
PubMed2001

Transcardiac 8-iso-prostaglandin F(2 alpha)generation from acute myocardial infarction heart: insight into abrupt reperfusion and oxidant stress.

8-iso-prostaglandin F(2 alpha)(8-iso-PGF(2 alpha)), a representative isoprostane, has been reported to be a reliable marker for oxidant stress in vivo. To examine if 8-iso-PGF(2 alpha)is generated in patients with acute myocardial infarction (AMI), we measured the level of immunoreactive 8-iso PGF(2 alpha)in the great cardiac vein as well as classical eicosanoids, 6-keto-prostaglandin F(1 alpha)(6-keto-PGF(1 alpha)) and thromboxane B(2)(TXB(2)) in the process of urgent coronary balloon angioplasty. Fourteen patients with anterior AMI were divided into two groups: the totally occluded (n=7) and the already perfused groups (n=7). In the former, transient elevation of 8-iso-PGF(2 alpha)was observed immediately after the angioplasty, i.e. the ratio of post-angioplasty level to pre-level was approximately 2.4 for 8-iso-PGF(2 alpha), 14 for 6-keto-PGF(1 alpha), and 5 for TXB(2). In the already perfused group, the levels of these eicosanoids were unchanged. In the totally occluded group, peak creatine phosphokinase in a peripheral vein was correlated with the level of 8-iso-PGF(2 alpha)(r(2)=0.841, P<0.01), but not with those of the other two eicosanoids. In conclusion, transcardiac 8-iso-PGF(2 alpha)generation is a reliable marker for the size of myocardium exposed to oxidant stress.

6-Ketoprostaglandin F1 alpha↗
PubMed2001

Apoptosis induced by hypertonicity in Madin Darley canine kidney cells: protective effect of betaine.

BACKGROUND: In mammals, the renal medulla is in a hypertonic environment related to the renal concentrating mechanism. Renal cells accumulate osmolytes such as betaine to protect cells from the perturbing effect of high concentration of electrolytes. Hypertonicity-induced cell death and the effect of betaine were investigated in Madin Darby canine kidney (MDCK) cells. METHODS: Cell viability was detected by 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyl tetrazolium bromide assay. DNA fragmentation was determined by FACS analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining and agarose gel electrophoresis. Activities of caspase-1, -3, -8, and -9 were measured. RESULT: When the cells were exposed to 700 mOsm medium for 24 h, 40% of the cells were detached. TUNEL staining showed that about 20% of detached cells were apoptotic, indicating that both necrosis and apoptosis contributed to the hypertonicity-induced cell death in MDCK cells. DNA laddering was demonstrated in hypertonic cells. Caspase-3, -8, and -9 activities of the adherent cells exposed to 700 mOsm for 24 h increased approximately 20-, 3-, and 4-fold the value of isotonic cells, respectively. However, there was no significant change in caspase-1 activity. Addition of 1 mM betaine into the medium protected the cells against the hypertonicity-induced cytotoxicity and apoptosis. Betaine prevented the induction of caspase-3, -8, and -9 activities after hypertonic exposure to about 50%. CONCLUSIONS: The present study demonstrates that (i) apoptosis is involved in the hypertonicity-induced cell death in MDCK cells; (ii) caspase-3, -8, and -9 may contribute to the apoptosis; and (iii) betaine has protective effect on the hypertonicity-induced apoptosis.

Animals↗
PubMed2001

Vestibular abnormalities in congenital disorders.

This paper reviews the histopathologic features of vestibular abnormalities in congenital disorders affecting the inner ear, based upon a comprehensive literature survey and a review of cases in our temporal bone collection. The review proceeds in three systematic steps. First, we surveyed associated diseases with the major phenotypic features of congenital abnormalities of the inner ear (including the internal auditory canal and otic capsule). Second, the vestibular anomalies are examined specifically. Finally, the anomalies are discussed from a developmental perspective. Among vestibular anomalies, a hypoplastic endolymphatic duct and sac are observed most frequently. Anomalies of the semicircular canals are also often observed. From embryological and clinical viewpoints, many of these resemble the structural features from fetal stages and appear to be associated with vestibular dysfunction. It is expected that progress in genetic analysis and accumulation of temporal bone specimens with vestibular abnormalities in congenital diseases will provide crucial information not only for pathology of those diseases, but also for genetic factors that are responsible for the specific vestibular abnormalities.

Animals↗
PubMed2000

Necrosis of the tongue after transient ischemic attack.

We report an unusual case of necrosis of the tongue after transient ischemic attack in a 67-year-old man. Angiography revealed occlusion of the right external carotid artery at the bifurcation of the common carotid artery. Debridement of the wound and removal of the necrotic tissue resulted in good healing.

Aged↗
PubMed2000

Liposarcoma of the tongue: case report and literature update.

Liposarcoma is an exceedingly rare tumor in the oral cavity. We report a case of a 70-year-old man with liposarcoma that presented as a lump on the tongue. The excised tumor was diagnosed as a well-differentiated lipoma-like liposarcoma. The majority of cases of well-differentiated liposarcoma follow a relatively benign course, but the disease has a high recurrence rate. It appears that accurate clinical and histopathologic diagnosis of this lesion is difficult. The prognosis seems to depend on the histologic type, size, and location of the lesion. Wide surgical excision is important for successful management of these liposarcomas.

Aged↗
PubMed2000

Evaluation of nasotracheal aspiration as a diagnostic tool for Rhodococcus equi pneumonia in foals.

The reliability of preparing bacteriological cultures from nasotracheal aspirates of foals routinely in order to diagnose R. equi pneumonia in foals was studied by isolating Rhodococcus equi from specimens obtained from 96 foals by nasotracheal aspiration with a silicon catheter. Results were compared with specimens obtained from 21 foals by transtracheal aspiration (percutaneous tracheal puncture). These 117 foals showed clinical signs of respiratory tract infection at sampling. R. equi was isolated from 14 of 21 (66.7%) specimens by transtracheal aspiration and from 59 of 96 (61.4%) specimens by nasotracheal aspiration, 649 of 655 isolates (99.1%) from the 73 positive specimens were virulent R. equi, and the culture-positive foals were diagnosed as having R. equi pneumonia. To assess the contamination of aspirates by organisms from the nasopharynx, the results of R. equi isolation from nasal swabs obtained from 56 of the 96 foals were compared to those obtained by nasotracheal aspiration from the same foals. R. equi was isolated from 2 of the 56 nasal swabs: one from a tracheal aspirate was positive, and the other was not. These results suggest that the nasotracheal aspiration technique, which is noninvasive and not associated with complications, could be used as an alternative to the transtracheal aspiration method, especially for the diagnosis of R. equi pneumonia in foals.

Actinomycetales Infections↗
PubMed1999

TUNEL staining of inner ear structures may reflect autolysis, not apoptosis.

A recent study (Usami et al., 1997) using the TUNEL method has suggested that age-related cell death in the senescence-accelerated mouse inner ear is due to apoptosis. TUNEL staining detects not only apoptosis but also late necrosis or autolysis because it detects DNA breaks. Autolysis may occur in inner ear structures during fixation. To determine whether or not age-related cell death is due to apoptosis, TUNEL staining of the inner ear of normal mice should be understood. However, studies of TUNEL staining of the normal inner ear have not yet been reported. We investigated whether the fixation method or the interval between the death of normal mice and the initiation of fixation influences the results of TUNEL staining of the inner ear. Marginal cells of the stria vascularis and hair cells of the saccule were TUNEL-positive, irrespective of the fixation method or the interval between death and fixation. Interdental cells, Reissner membrane cells, fibrocytes in the suprastrial region, and inner and outer hair cells were also occasionally stained. Transmission electron microscopy showed no morphological characteristics of apoptosis in the hair cells of the saccule. Moreover, patterns of TUNEL staining in the normal and senescence-accelerated mouse inner ear were similar. These stained tissues may require a high level of oxygen, making them more susceptible to autolysis. We concluded that the results of TUNEL staining in the inner ear require confirmation by morphological studies.

Animals↗
PubMed1999

4-methylcatechol, a potent inducer of nerve growth factor synthesis, protects spiral ganglion neurons from aminoglycoside ototoxicity--preliminary report.

The degeneration of spiral ganglion neurons after hair cell destruction following aminoglycoside ototoxicity is associated not only with the direct effect on the neurons, but also with a loss of neurotrophic factors provided by auditory hair cells. The neurotrophic factors, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), have been reported to be effective in enhancing neuronal survival against aminoglycoside ototoxicity in vivo. To determine whether 4-methylcatechol (4-MC), a potent inducer of nerve growth factor synthesis, can protect spiral ganglion neurons after aminoglycoside treatment in vivo, we studied the spiral ganglion neurons of gentamicin (GM)-treated mice with or without 4-MC administration. We found that the number of surviving spiral ganglion neurons of 4-MC-treated animals was significantly greater than for those treated with GM alone. Our results suggest that 4-MC promotes synthesis of NGF (and/or other neurotrophins), which enhances spiral ganglion neuron survival after gentamicin treatment.

Animals↗
PubMed1999

Does TUNEL staining during peri- and post-natal development of the mouse inner ear indicate apoptosis?

Terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labelling (TUNEL) is being used more frequently to investigate programmed cell death (PCD). We have applied this method in order to examine how PCD is involved in the development of the mouse inner ear. In a series of studies, we identified a population of TUNEL-positive cells in the perinatal mouse ear that could not be regarded as apoptosis based upon morphological features of the nuclei. Theoretically, TUNEL detects DNA fragmentation, which can also occur in necrosis. Other authors regard TUNEL-positive cells in the sensory epithelia of the rat equilibrium organs between gestational day (GD) 19 and 7 days after birth (DAB) as apoptosis. We determined whether or not cells in the inner ear of perinatal and post-natal mice were TUNEL-positive due to apoptosis. We stained the inner ears of BALB/c mice aged GD17.5-4 weeks by the TUNEL method and analysed morphology by light microscopy and transmission electron microscopy (TEM). TUNEL-positive cells were distinct in the saccule from DAB3, and in the cochlea from DAB8. The number of TUNEL-positive cells in the hair cells of the saccule and in the cochlea increased with age, and seemed to reach a plateau just before 2 weeks of age. However, morphological analyses did not reveal findings characteristic of apoptosis. We conclude that these TUNEL-positive cells were labelled not because of apoptosis, but due to necrosis or post-mortem autolysis. We surmise that TUNEL staining can identify vulnerable cells of the inner ear that consume high levels of oxygen and easily undergo autolysis.

Animals↗
PubMed1998

Osteoma with cholesteatoma in the external auditory canal.

We report an unusual case of a 13-year-old girl with a benign osteoma associated with a cholesteatoma in the external auditory canal and serous otitis media. The osteoma was located in the antero-inferior wall of the right external auditory canal. A cholesteatoma was present between the osteoma and the tympanic membrane. Computed tomography revealed a soft tissue density within the external auditory canal and in the middle ear cleft. The shadow in the middle ear cleft was considered to represent the serous otitis media. Surgical removal of the osteoma and cholesteatoma proved successful, and no recurrences or complications have occurred in the first year postoperatively.

Adolescent↗
PubMed1998

Programmed cell death in the development of the mouse external auditory canal.

Programmed cell death (PCD) is an essential event for development. The purpose of this work was to ascertain how PCD, in vivo designated apoptosis, is involved in the development of the external auditory canal. We performed a time sequence study of the distribution of apoptosis during the development of external auditory canal (EAC) of the mouse. ICR mice ranging in age from embryonic day 11.5 (E11.5) to 12 days after birth (DAB) were used in the present study. A part of each head including both ears was removed and was processed according to its purpose. Light and electron microscopy for morphological studies and TUNEL method (Gavrieli et al. [1992] J Cell Biol., 119:493-501) for histochemical studies were used. On E11.5, distinct TUNEL-positive staining occurred in the branchial arch. Between E15.5 and 1DAB, TUNEL-positive cells were observed throughout the EAC and the number of these cells decreased with age. On E15.5 and E16.5, numerous TUNEL-positive cells were observed in a cavity remained in the epithelial plate. Transmission electron microscopy revealed that these cells had the features of apoptosis. From 3-12 DAB, no apoptosis was observed in the EAC except for the terminal differentiation of the skin of the EAC. Apoptosis was not observed during recanalization of the EAC, but occurred during the formation of the epithelial plate. The investigation established that PCD is involved in the formation of the epithelial plate, whereas only cornification of the epithelium of the EAC is associated with recanalization.

Animals↗
PubMed1998

Programmed cell death in the developing epithelium of the mouse inner ear.

Programmed cell death is as essential to development as is proliferation. Thus, the objective of this study was to elucidate the spatiotemporal involvement of programmed cell death in the development of the inner ear epithelia. Programmed cell death is seen in situ as apoptosis. A time-sequence study was performed on the distribution of apoptosis during the development of the inner ear epithelia of the mouse using the TdT-mediated dUTP-biotin nick labeling (TUNEL) method to detect apoptosis histochemically. Apoptosis occurred during the early stages of development of the inner ear and took place earlier in the organs of equilibrium than in the cochlea. These periods corresponded to those of active proliferation of epithelial cells in the inner ear. Since cell-cell interactions change after the removal of neighboring cells by apoptosis, apoptosis may influence cytodifferentiation.

Animals↗
PubMed1998

Gap junction change in supporting cells of the organ of Corti with ryanodine and caffeine.

It has been demonstrated that the gap junctions of the supporting cells of the organ of Corti are controlled by H+ and Ca2+. Inside these cells there is a tubular structure. It is supposed that this network is endoplasmic reticulum. Calcium release from inside the cells, and the effect of calcium on the gap junctions of these cells, were investigated under whole cell clamping application of ryanodine and caffeine. Membrane capacitance and membrane resistance were calculated, with corrections for changes in whole cell parameters. Ryanodine-treated cells (1 microM-10 mM), caffeine-treated cells (5 mM 500 nM) and A23187-treated cells were uncoupled at their gap junctions. Therefore, Ca2+ plays a role in the uncoupling of the gap junctions in supporting cells of the organ of Corti from inside the cells.

Animals↗