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Biomedical subjects

Sugata Takahashi

Publications and source records attributed to Sugata Takahashi.

At least 19 recordsLinked to original sources
PubMed2007

Demographic characteristics of 3,659 Japanese patients with obstructive sleep apnea-hypopnea syndrome diagnosed by full polysomnography: associations with apnea-hypopnea index.

Information on obstructive sleep apnea-hypopnea syndrome (OSAHS) in Japan has been limited. The purposes of this clinical study were to evaluate the demographic characteristics of Japanese OSAHS patients and to assess how demographic factors are associated with OSAHS severity. We analyzed 3,659 OSAHS patients who underwent polysomnographic evaluation between January 2000 and December 2004 at 11 hospitals in Niigata Prefecture, Japan. Data consisted of apnea-hypopnea index (AHI) and demographic characteristics, including sex, age, and body-mass index, for statistical analysis. Levels of obesity were classified according to the WHO criteria. The male-to-female patient ratio for OSAHS was 4.6, and male patients presented more severe OSAHS than female patients. High AHI and a high proportion of moderate to serious OSAHS (AHI > or = 15) were found among the patients in their 30s, as well as female patients in their 70s and male patients in their 80s. The AHI and the proportion of moderate-to-serious OSAHS (AHI > or = 15) were greater in patients classified as underweight than in normal weight patients. In conclusion, there is a higher male predominance in the prevalence of OSAHS, and in both sexes, the results suggest different pathophysiological mechanisms of deteriorating OSAHS between adults under age 55 and adults 55 years or over. In addition, underweight patients exhibit more severe OSAHS than normal weight patients.

Age Distribution↗
PubMed2006

Investigation into dizziness before and after Epley's maneuver for benign paroxysmal positional vertigo using stabilometry.

OBJECTIVE: To investigate the cause of dizziness after Epley's maneuver using stabilometry. METHODS: Subjects were 35 patients with posterior canal type BPPV. First we performed stabilometry, next Epley's maneuver, then stabilometry was performed again. The enveloped area and the locus length per second of stabilometry were compared. RESULTS: Seventeen patients reported a feeling of dizziness after the treatment, whereas the other 18 patients did not. The patients were divided into two groups: 17 patients with dizziness (WD) and 18 patients without dizziness (WOD) after the treatment. In the WD group, the enveloped area (P=0.0495) and the locus length per second (P=0.0099) before Epley's maneuver were significantly lower than those after Epley's maneuver. In the WOD group, there was no significant difference in the stabilometry parameter between values obtained before and after Epley's maneuver. There were no significant differences found in either parameter between these two groups either before or after applying Epley's maneuver. CONCLUSIONS: Epley's maneuver is a treatment for the posterior semicircular canal. Malfunction of the otolith organ remains. It is considered that the cause of dizziness after Epley's maneuver comes from otolith dysfunction.

Adult↗
PubMed2006

Inactivation of tumor suppressor Dlg1 augments transformation of a T-cell line induced by human T-cell leukemia virus type 1 Tax protein.

BACKGROUND: The interaction of human T-cell leukemia virus type 1 (HTLV-1) Tax1 protein with the tumor suppressor Dlg1 is correlated with cellular transformation. RESULTS: Here, we show that Dlg1 knockdown by RNA interference increases the ability of Tax1 to transform a mouse T-cell line (CTLL-2), as measured interleukin (IL)-2-independent growth. A Tax1 mutant defective for the Dlg1 interaction showed reduced transformation of CTLL-2 compared to wild type Tax1, but the transformation was minimally affected by Dlg1 reduction. The few Tax1DeltaC-transduced CTLL-2 cells that became transformed expressed less Dlg1 than parental cells, suggesting that Dlg1-low cells were selectively transformed by Tax1DeltaC. Moreover, all human T-cell lines immortalized by HTLV-1, including the recombinant HTLV-1-containing Tax1DeltaC, expressed less Dlg1 than control T-cell lines. CONCLUSION: These results suggest that inactivation of Dlg1 augments Tax1-mediated transformation of CTLL-2, and PDZ protein(s) other than Dlg1 are critically involved in the transformation.

Animals↗
PubMed2006

Comparison between stabilometry with and without head tilts in a roll plane.

OBJECTIVE: We examined the influence of head-tilting on stabilometry, which is similar to positional nystagmus in a sitting position. METHODS: The subjects were 35 healthy individuals and 11 patients with unilateral vestibular disorder. We compared parameters measured in an upright position and those with left head-tilt or right head-tilt. We used Wilcoxon's signed ranks test for statistical analysis. RESULTS: In the group of healthy adults, the Enveloped area with left head-tilt and right head-tilt increased significantly compared to that in the upright position (P=0.0111). The parameters that decreased significantly were Locus length per unit area (P=0.0007). The center of gravity on the Y-axis shifted backward significantly (P<0.0001). In the group of unilateral vestibular disorder, there were no parameters that showed significant difference CONCLUSION: One could argue that a combination of displacement of the body itself, influence of proprioceptive sensation, and influence of otolith affects the output of stabilometry. It would be possible to develop this test if the first and the second are excluded.

Adult↗
PubMed2006

Endolymphatic sac tumor located around semicircular canals.

We report a case of endolymphatic sac tumor (ELST). A 48-year-old female had recurrent and slowly progressive hearing loss, accompanied with dizziness like Meniere's disease. A tumor was located around the semicircular canals, and was detected on CT and MRI. The patient underwent total removal of the tumor using a transmastoid approach. Histopathological examinations agreed with features of an ELST. The tumor was highly suspected to have originated from the rugose portion of the endolymphatic sac or the endolymphatic duct, based on surgical and imaging studies. Structure of the membranous labyrinth was preserved regardless of the existence of the tumor around semicircular canals with bone destruction. ELSTs seem to have an osteolytic or osteophilic nature, by examining patterns of tumor infiltration.

Ear Neoplasms↗
PubMed2006

Caspase-3, caspase-8, and nuclear factor-kappaB expression in human cholesteatoma.

BACKGROUND: Cholesteatoma is characterized by the accumulation of keratinizing epithelium resulting from the proliferation and differentiation of epithelium. Researchers are presently unraveling the role that apoptosis plays in the disease seen in cholesteatoma epithelium. Caspases play a key role in apoptosis. Caspase-8, which is activated by the induction of tumor necrosis factor-alpha, leads to activation of caspase-3, which activates apoptotic nucleases. Nuclear factor-kappaB is a transcription factor known to inhibit apoptosis induced by tumor necrosis factor-alpha. HYPOTHESIS: In this study, we hypothesized that expression of caspase-3, caspase-8, and nuclear factor-kappaB is uniquely connected to the proliferation, differentiation, and programmed cell death of keratinocytes during the growth and development of cholesteatoma. METHODS: We obtained 41 cholesteatoma specimens for this study. The presence of these proteins in cholesteatoma was examined using immunohistochemistry and a colorimetric assay system. We also examined the patterns of apoptosis by using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining. RESULTS: Using the immunoperoxidase staining method, caspase-3 was found to be densely localized in the spinous and granular layers of cholesteatoma epithelium; caspase-8 was also found in the granular layer. Nuclear factor-kappaB was localized densely in the perinuclear region of the epithelium. The results obtained with immunoperoxidase staining agreed with those obtained with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining. In addition, the colorimetric assay method was used to measure the activity of caspase-3. CONCLUSION: These findings suggest that caspase-3 and caspase-8 play important roles in programmed cell death, which results in the accumulation of keratin debris during the growth of cholesteatoma. Nuclear factor-kappaB was found in cholesteatoma epithelium, but the transcription factor appeared to be inactivated.

Adolescent↗
PubMed2006

Transcranial fluorescence imaging of auditory cortical plasticity regulated by acoustic environments in mice.

Functional brain imaging using endogenous fluorescence of mitochondrial flavoprotein is useful for investigating mouse cortical activities via the intact skull, which is thin and sufficiently transparent in mice. We applied this method to investigate auditory cortical plasticity regulated by acoustic environments. Normal mice of the C57BL/6 strain, reared in various acoustic environments for at least 4 weeks after birth, were anaesthetized with urethane (1.7 g/kg, i.p.). Auditory cortical images of endogenous green fluorescence in blue light were recorded by a cooled CCD camera via the intact skull. Cortical responses elicited by tonal stimuli (5, 10 and 20 kHz) exhibited mirror-symmetrical tonotopic maps in the primary auditory cortex (AI) and anterior auditory field (AAF). Depression of auditory cortical responses regarding response duration was observed in sound-deprived mice compared with naïve mice reared in a normal acoustic environment. When mice were exposed to an environmental tonal stimulus at 10 kHz for more than 4 weeks after birth, the cortical responses were potentiated in a frequency-specific manner in respect to peak amplitude of the responses in AI, but not for the size of the responsive areas. Changes in AAF were less clear than those in AI. To determine the modified synapses by acoustic environments, neural responses in cortical slices were investigated with endogenous fluorescence imaging. The vertical thickness of responsive areas after supragranular electrical stimulation was significantly reduced in the slices obtained from sound-deprived mice. These results suggest that acoustic environments regulate the development of vertical intracortical circuits in the mouse auditory cortex.

Acoustic Stimulation↗
PubMed2006

Evidence of antibody production in the rat cervical lymph nodes after antigen administration into the cerebrospinal fluid.

We previously showed histologically that, in the rat, the cerebrospinal fluid drains from the subarachnoid space along the olfactory nerves to the nasal lymphatics and empties into the superficial and deep cervical lymph nodes. The present study was performed to investigate whether these lymph nodes play a role in the immune response of the central nervous system. For this purpose, keyhole limpet hemocyanin conjugated with fluorescein isothiocyanate (KLH-FITC) was administered into the subarachnoid space of the rat brain, and the time-kinetics and location of FITC and anti-FITC antibody forming cells in the cervical lymph nodes were studied histologically and immunohistochemically. FITC fluorescence was detected in superficial and deep cervical lymph nodes as well as the subarachnoid space and the nasal mucosa 2 h after FITC-KLH injection into the subarachnoid space. The specific antibody-forming cells first appeared in both the superficial and deep cervical lymph nodes on the 4th day after antigen administration although the reaction was more intense in the deep than in the superficial cervical lymph nodes. These cells were located in the medullary cords of the cervical lymph nodes. The number of antibody forming cells increased thereafter, reached a peak around the day 6, and then declined on day 10. These findings indicate that antigens introduced in the cerebrospinal fluid are drained into the cervical lymph nodes through the nasal lymphatics and initiate the antigen-specific immune response there. Thus, the cervical lymph nodes probably act as a monitoring site for cerebrospinal fluid and play a major role in the central nervous system immune response.

Animals↗
PubMed2005

Differential diagnosis and management of airway obstruction in Riedel's thyroiditis: a case report.

A case of Riedel's thyroiditis, which required differential diagnosis from malignant tumor of the thyroid gland, and the strategy of surgical treatment is reported. Differential diagnosis prior to the treatment was difficult, but the diagnosis was decided by the histopathological findings of an open biopsy specimen obtained simultaneously in an emergent tracheostomy required for progressive airway stenosis. First-choice treatment for Riedel's thyroiditis has been reported to be steroid administration, however, this treatment was difficult for the present case due to continuous steroid treatment for complicated neuro-Behçet's disease. Therefore, vaporization of the lesion using KTP-LASER and T-tube placement was chosen for the surgical treatment strategy of this patient. After 1 year of follow-up since the operation, the T-tube was removed and the tracheostoma was closed, and the patient has remained symptom free for 412 years. Careful long-term follow-up is still needed for this patient to prevent recurrence of the disease, subsequent complications of autoimmune diseases, and thyroid malignancies.

Airway Obstruction↗
PubMed2005

Middle ear carcinoma originating from a primary acquired cholesteatoma: a case report.

OBJECTIVES: To describe middle ear carcinoma originating from the matrix of primary acquired cholesteatoma in a 43-year-old man and to discuss the relationship between middle ear carcinoma and cholesteatoma. STUDY DESIGN: Case report. SETTING: Department of Otolaryngology, Head and Neck Surgery of Niigata University Medical and Dental Hospital, which is a tertiary care center, Niigata, Japan. PATIENT: A 43-year-old man demonstrated symptoms resembling those of cholesteatoma: facial palsy, gradually progressive hearing loss, and chronic draining of the right ear. Other objective findings also supported a finding of cholesteatoma, but a computed tomographic scan and magnetic resonance imaging scan showed a well-enhanced mass and extensive bony erosion in the middle ear. At surgery, a granulous tumor in the mastoid cavity was diagnosed as squamous cell carcinoma, and closely coexisting cholesteatoma was found. Surgical specimen demonstrated carcinoma and cholesteatoma in the same field. INTERVENTION: Radiation and chemotherapy were performed followed-up by mastoidectomy. CONCLUSION: Because middle ear carcinoma has a poor prognosis, it is important to detect lesions early. It is necessary to consider that middle ear carcinoma arises from not only chronic otitis media or surgical invasion but also from primary acquired cholesteatoma.

Adult↗
PubMed2005

[Congenital anterior cervical fistula originating from the Wharton duct].

A 14-year-old boy presented with a spontaneous anterior cervical fistula, which exuded a saliva-like fluid during eating. Cervical examination revealed a hole 7 mm posterior to the hyoid bone, 5mm left of the median. Magnetic resonance imaging showed a low-intensity spindly mass with high-intensity margins. The mass was connected to the left submandibular gland. Contrast radiography of the fistula using Gastrografin demonstrated an ascending fistula that extended to the submandibular area. Intraoperatively, the fistula was shown to have ascended superficial to the level of the anterior cervical muscles, and it formed a cyst anterior to the hyoid bone. It then continued to the left submandibular gland. The fistula and submandibular gland were removed together. Wharton's duct was not found, and the orifice of the duct was unclear. Pathological examination of the fistula showed the lining epithelium at the side of the submandibular gland to be composed of columnar epithelial cells with stratified squamous cells at the epidermal side. Several acinar systems were found along the orifice of the fistula. There have been no previous reports of the Wharton duct running from the submandibular gland to the anterior cervical skin.

Adolescent↗
PubMed2004

The dynamics of precursor cells in the olfactory epithelium of juvenile and adult guinea pigs.

The dynamics of precursor cells in the olfactory epithelium of juvenile and adult guinea pigs were examined by immunohistochemical double staining using bromodeoxyuridine (BrdU), the neural cell adhesion molecule (N-CAM) and the protein gene product 9.5 (PGP9.5). Expression of apoptotic cells in the olfactory epithelium with the use of the TdT-mediated dUTP biotin nick end labeling (TUNEL) method was also observed. BrdU was given to healthy guinea pigs at the ages of 2 weeks and 6 months old. Tissue specimens were serially collected 1 h to 28 days after administration. BrdU-labeled cells were seen above the basal cell layer after 1 h and migrated to the middle layer of the olfactory epithelium, after 1 day in juveniles and 5 days in adults with expression of N-CAM. PGP9.5 was observed in BrdU-labeled cells after 5 days in juvenile guinea pigs and 7 days in adult. At 14 days after administration, BrdU-labeled cells in the epithelium appeared to decrease. However, a few of these cells were recognized above the basal cell layer after 28 days. The number and location of TUNEL-positive cells did not significantly differ between the juvenile and adult olfactory epithelium. Therefore, we conclude that the division speed from stem cells in juveniles is faster than that in adults, and apoptosis is unaffected by aging in the normal olfactory epithelium.

Age Factors↗
PubMed2004

A method for displaying two images on a screen in distance medical education.

This article describes a method for simultaneously displaying several images on a screen during an online multimedia presentation. Users with 'REALPLAYER' software and Web browsers can view images with synchronous audio on their personal computers via the Internet. Medical researchers and physicians often find it useful to compare images after treatment with those before treatment, by displaying several arranged images simultaneously. Medical care providers can browse this type of multimedia content in their offices and universities at their convenience. There presently exist two methods for creating multimedia content with voice and images using RealSystem technology. Electronic lectures of otorhinolaryngology explaining new surgical procedures for patients with chronic otitis media were created with this method and made available to otorhinolaryngologists through the Internet.

Computer Terminals↗
PubMed2004

Cytoarchitecture of the normal rat olfactory epithelium: light and scanning electron microscopic studies.

The three-dimensional cytoarchitecture of the normal rat olfactory epithelium was examined by scanning electron microscopy (SEM) of KOH digested tissues as well as by light and transmission electron microscopy of plastic sections. Observations specimens from the lateral side of the olfactory epithelium allowed identification of four cell types by their surface structure: olfactory neurons, supporting cells, basal cells, and duct cells of the Bowman's gland. The olfactory neurons were characterized by the presence of a thick apical process (i.e., dendrite) and a thin basal process (i.e., axon). These olfactory neurons tended to be aligned along the vertical axis of the epithelium. Immature olfactory neurons were present at the basal part of the epithelium and had a pear-shaped cell body with a thin and long axon and a short dendrite which failed to reach the epithelial surface. Supporting cells were roughly columnar in shape and occupied the full length of the epithelium. They became thinner in the basal two thirds of their length but had branched foot processes spreading on the basal surface of the epithelium. Basal cells located in the basal epithelial region were oval, round or cuboidal and present among the foot processes of the supporting cells. The ducts of the Bowman's gland entered the epithelium from the lamina propria and took straight, perpendicular courses within the epithelium. These intraepithelial ducts were composed of several slender cells. The acinar cells are sometimes present in the epithelium and appeared as a globular bulge of the duct at the basal part of the epithelium. SEM observation of the basal surface of the olfactory epithelium also clearly showed that axon bundles were surrounded by the sheet-like processes of Schwann cells, the investment being found at the base of the epithelium just before axon bundles leave the epithelium.

Animals↗
PubMed2003

[Head and neck malignant tumors in Niigata Prefecture. The first report: demographics in 4,053 cases].

In 1986, the Niigata Registration Committee of Head and Neck Malignant Tumors was established by otolaryngologists in Niigata Prefecture to register cases of head and neck malignancies. Between 1986 and 1999, 4,053 cases were registered and we epidemiologically analyzed them. Men accounted for 2,866 (70.7%) and women for 1,187 (29.3%). The mean age and standard deviation of the age at diagnosis were 63.4 and 12.4 in men and 59.5 and 16.0 in women. The larynx was the most common site (1,154 cases) in men, followed by the oral cavity (360 cases), hypopharynx (273 cases), mesopharynx (239 cases), and maxillary sinus (154 cases). The thyroid gland was the most common site (416 cases) in women, followed by the oral cavity (214 cases), nasal cavity and paranasal sinuses (excluding the maxillary sinus) (76 cases), salivary glands (72 cases), and mesopharynx (71 cases). The site with the highest mean age was the lip (71.3 years old) in men and the larynx (68.7 years old) in women. The thyroid gland showed the lowest mean age for both genders (men: 56.7, women: 53.6), and that markedly lowered the female mean age because the thyroid gland accounted for one third of all cases in women. Comparing our data to national statistics, the incidence of oral malignancy was almost half in our data. We concluded that, in Niigata Prefecture, the dental professions treated as many cases of oral malignancy as we did. A high gender ratio (male/female) was seen for the larynx (22.2), hypopharynx (4.3), and mesopharynx (3.4). It was more than 1 and less than 2 for the oral cavity, salivary gland, neck lymphoma, ear, and nasal cavity and paranasal sinuses (excluding the maxillary sinus). The thyroid gland showed the lowest gender ratio (0.3), which was the only female-dominant site. We concluded that many sites of malignant head and neck tumors have a lower gender ratio than previously anticipated.

Adolescent↗
PubMed2002

Surgical treatment of 52 cases of auditory ossicular malformations.

OBJECTIVE: The aim of this study was to determine the relationship between hearing improvements and the pathological conditions of auditory ossicular malformations. METHODS: Fifty-two ears (49 patients) with auditory ossicular malformations without congenital aural atresia were studied. The classification of the pathological conditions was based on surgical findings. Group 1 showed defects in the incudo-stapedial (I-S) joint, Group 2, fixation of the stapes, Group 3, fixation of the malleus and incus and Group 4, defects in the I-S joint with fixation of the stapes. Hearing improvements at the final examination were designated as successful when both of the following were satisfied. (1) Air-bone gap was reduced to 20 dB or less. (2) Postoperative hearing gain exceeded 15 dB. RESULTS: Successful hearing improvements after operations were achieved in 20 ears (95%) in Group 1, 21 ears (91%) in Group 2, three ears (75%) in Group 3 and two ears (50%) in Group 4. They were observed in 88% of all cases. CONCLUSIONS: Postoperative hearing improvements of auditory ossicular malformations yielded good results, particularly in Groups 1 and 2. In retrospect, the unsuccessful cases with fixation of the stapes would have been improved if stapedectomy were chosen rather than mobilization. In defects to the long process of Group 4, we wished to perform a reconstruction using the malleus attachment piston after small-fenestra stapedectomy with regard to the long-term hearing results.

Adolescent↗
PubMed2002

Malignant lymphoma in the head and neck associated with benign lymphoepithelial lesion of the parotid gland.

Lymphoepithelial lesion is a benign lymphoproliferative disease occasionally arises in the salivary glands, but association with malignant diseases or autoimmune diseases has also been discussed. We herein present three cases of malignant lymphoma arose in the parotid gland and the lacrimal gland, following parotid surgery for benign lymphoepithelial lesion (BLEL) of the parotid gland. Two cases had mucosa associated lymphoid tissue (MALT) lymphoma in the parotid gland; one arose in the ipsilateral parotid gland as a recurrent swelling, and the other arose in the contralateral parotid gland of the previous BLEL surgery. The third case of malignant lymphoma arose in the lacrimal gland on the ipsilateral side, and the following contralateral parotid gland remained BLEL. All three patients were female, and one patient had a past history of Sjögren's syndrome and Hashimoto's disease. All three patients were treated by chemotherapy and one patient received additional radiotherapy. To follow-up lymphoproliferative diseases in the salivary glands such as BLEL, careful observation should be made on the same gland, other major salivary glands, and other organs in the head and neck, especially in females with autoimmune diseases.

Aged↗