Biomedical subjects

Izumi Koizuka

Publications and source records attributed to Izumi Koizuka.

At least 19 recordsLinked to original sources

PubMed2007

Life-style and environmental factors in the development of nasal NK/T-cell lymphoma: a case-control study in East Asia.

Cases of nasal NK/T-cell lymphoma (NKTCL) occur occasionally in Asian and Latin American countries but rarely in Western countries. The etiological role of life-style and environmental factors in nasal NKTCL was investigated. Five university hospitals in Japan and one each in Korea and China participated in this study; a total of 88 cases and 305 hospital controls were accrued during 2000-2005. The odds ratio (OR) of NKTCL obtained after adjustments of age, sex and country was 4.15 (95% confidence interval (CI), 1.74-9.87) for farmers, 2.81 (CI, 1.49-5.29) for producers of crops, 4.01 (CI, 1.99-8.09) for pesticide users, 11.65 (CI, 1.17-115.82) for residents near garbage burning plants, 2.95 (CI, 1.25-6.95) for former drinkers, and 0.49 (CI, 0.23-1.04) for current smokers. The ORs for crop producers, who minimized their exposure to pesticides by using gloves and glasses, and sprinkling downwind at the time of pesticide use, were 3.30 (95% CI, 1.28-8.54), 1.18 (95% CI, 0.11-12.13) and 2.20 (95% CI, 0.88-5.53), respectively, which were lower than those for producers who did not take these precautions. Exposure to pesticides and chemical solvents could be causative of NKTCL. Taken together, life-style and environmental factors might be risk factors for NKTCL.

Adult↗

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

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

Proteomic surveillance of autoantigens in relapsing polychondritis.

Relapsing polychondritis (RP) is a systemic inflammatory disease, in which autoimmunity to cartilage-related components is thought to be involved in its pathogenesis. However, the autoimmune profile in RP has not been studied fully. We therefore investigated autoantibodies/autoantigens in RP comprehensively, by 2-dimensional electrophoresis (2DE), subsequent western blotting (WB) and mass spectrometry, using cell-extracted proteins as the antigen source. As a result, we detected 15 autoantigens on 2DE-WB, and further identified five of them. On average, one RP serum recognized approximately 8 out of the 15 autoantigens. Frequencies of the autoantibodies to the 5 identified antigens of tubulin alpha ubiquitous/6, vimentin, alpha enolase, calreticulin, and colligin-1/-2 were 91%, 46%, 36%, 82%, and 36%, respectively. ELISA using recombinant proteins for them revealed that frequencies of the autoantibodies to tubulin alpha ubiquitous, vimentin, alpha enolase, calreticulin, and colligin-1 were 36%, 64%, 46%, 27%, and 18%, respectively. Our data demonstrated that the autoimmune reaction was not restricted to cartilagerelated components, rather a variety of autoimmune responses occurred in patients with RP, which may be involved in the pathophysiology of RP. In addition, the proteomic approach using cell-extracted proteins would be a powerful way to investigate autoantigens.

Autoantibodies↗

PubMed2006

[Flexibility of adaptation of vestibule-ocular reflex in human beings].

Vestibulo-ocular reflex (VOR) makes images remain relatively stable on the retina. To keep appropriate performance and minimize image slip throughout life, VOR is subject to long-term adaptive regulation by visual input. It has been reported that adaptive changes in VOR gain (eye velocity/head velocity) are evoked either by fitting subjects with magnifying, miniaturizing, or reversing spectacles during normal behavior or by moving a large visual field in or out of phase relative to the subject's head movement. These feature frequency-selectivity. We studied the flexibility of adaptive gain change in VOR required by a horizontal visual-vestibular mismatch in earth vertical axis rotation (EVAR), including adaptive gain change from EVA to off-vertical axis rotation (OVAR) and other velocities. The visual-vestibular mismatch was made by oscillating subjects in EVAR for 30 minutes at 0.3 Hz with the peak velocity of 30 deg/s and 60 deg/s, synchronized with both in-phase (gain decrease: x 0 experiment) and out-of-phase (gain increase: x 2 experiment) sinusoidal rotation of white-black stripe patterns. Subjects were 19 healthy adult volunteers with no history of neurological symptoms. Horizontal and vertical eye positions were recorded by bitemporal DC-coupled electrooculography. In the x 2 adaptation experiment with 0.3 Hz at the peak velocity of 30 deg/s, the percent change in gain (post-pre/ pre) was 110% at the same stimulation and 100% at 40 deg/s in EVA. In the x 0 adaptation experiment with 0.3 Hz at the peak velocity of 30 deg/s, the percent change in gain was -50% at the same stimulation in EVA. In the x 2 adaptation experiment with 0.3 Hz at the peak velocity of 60 deg/s, the percent change in gain was 66% at the same stimulation in EVA, 30% at the same stimulation in nose-up position, and 74% at the same stimulation in nose-down position. In the x 0 adaptation experiment with 0.3 Hz at the peak velocity of 60 deg/s, the percent change in gain was -34% at the same stimulation in EVA. No change in VOR gain was observed at other peak velocities. These results suggest that VOR adaptation depends frequency and maximum angular head velocity, and this characteristic is observed in OVAR.

Adaptation, Ocular↗

PubMed2005

Comparing the accuracy of video-oculography and the scleral search coil system in human eye movement analysis.

The measurement of eye movements in three dimensions is an important tool to investigate the human vestibular and oculomotor system. The primary methods for three dimensional eye movement measurement are the scleral search coil system (SSCS) and video-oculography (VOG). In the present study, we compare the accuracy of VOG with that of SSCS using an artificial eye. We then analyzed the Y (pitch) and Z (yaw) component of human eye movements during saccades, smooth pursuit and optokinetic nystagmus, and the X (roll) component of human eye movement during the torsional vestibulo-ocular reflex induced by rotation in normal subjects, using simultaneous VOG and SSCS measures. The coefficients of the linear relationship between the angle of a simulated eyeball and the angle measured by both VOG and SSCS was almost unity with y-intercepts close to zero for torsional (X), vertical (Y) and horizontal (Z) movements, indicating that the in vitro accuracy of VOG was similar to that of SSCS. The average difference between VOG and SSCS was 0.56 degrees , 0.78 degrees and 0.18 degrees for the X, Y and Z components of human eye movements, respectively. Both the in vitro and in vivo comparisons demonstrate that VOG has accuracy comparable to SSCS, and is a reliable method for measurement of three dimensions (3D) human eye movements.

Adult↗

PubMed2005

Ear involvement in patients with rheumatoid arthritis.

OBJECTIVE: This study evaluates the degree of hearing impairment in patients with rheumatoid arthritis (RA) and examines the correlation between hearing impairment and the clinical data or chemical mediators. BACKGROUND: Both sensorineural hearing loss (SNHL) and conductive hearing loss (CHL) have been reported in patients with RA, but the results of most studies are not in agreement, and the pathophysiology of hearing impairment in RA is not well known. METHODS: Hearing in patients with RA and controls was examined using pure-tone audiometry and tympanometry. Also, the amounts of pro-inflammatory cytokines and matrix metalloproteinases in addition to antibodies against type II collagen in plasma of the patients with RA were determined using enzyme-linked immunosorbent assay. RESULTS: The frequency of SNHL in the patients with RA was higher than in normal controls (36.1% versus 13.9%), and bone conduction at 2,000 Hz differed significantly between the patients with RA and the controls (p < 0.01). Moreover, the presence of SNHL was related to ESR (p < 0.05), plasma interleukin-6 (p < 0.05), and plasma matrix metalloproteinase-3 (p < 0.001). On the other hand, CHL was not observed, whereas As-type tympanograms increased in the patients with RA (p < 0.01). Abnormal tympanograms were not related to any clinical findings or any chemical mediators tested. CONCLUSION: We demonstrated that there is increased SNHL in patients with RA, which may result from systemic inflammation and tissue injury, and increased latent-type CHL caused by stiffness of the middle ear system whose mechanisms are not yet clear.

Acoustic Impedance Tests↗

PubMed2004

Properties of horizontal semicircular canal nerve-activated vestibulospinal neurons in cats.

Axonal pathways, projection levels, and locations of horizontal semicircular canal (HC) nerve-activated vestibulospinal neurons were studied. The HC nerve was selectively stimulated. Vestibulospinal neurons were activated antidromically with four stimulating electrodes, inserted bilaterally into the lateral vestibulospinal tracts (LVST) and medial vestibulospinal tracts (MVST) at the C1/C2 junction. Stimulating electrodes were also positioned in the C3, T1, and L3 segments and in the oculomotor nuclei. Most HC nerve-activated vestibulospinal neurons were located in the ventral portion of the medial, lateral, and the descending nuclei. Among the 157 HC nerve-activated vestibular neurons, 83 were antidromically activated by stimulation at the C1/C2 junction. Of these 83 neurons, axonal pathways of 56 HC nerve-activated vestibulospinal neurons were determined. Most (48/56) of these had axons that descended through the MVST, with the remainder (8 neurons) having axons that descended through the ipsilateral (i-) LVST. Laterality of the axons' trajectories through the MVST was investigated. The majority of vestibulospinal neurons (24/28) with axons descending through the contralateral MVST were also antidromically activated from the oculomotor nucleus, whereas almost all vestibulospinal neurons (19/20) with axons descending through the i-MVST were not. Most HC nerve-activated vestibulospinal neurons were activated antidromically only from the C1/C2 or C3 segments. Only one neuron that was antidromically activated from the T1 segment had an axon that descended through the i-LVST. None of the HC nerve-activated vestibulospinal neurons were antidromically activated from the L3 segment. It is likely that the majority of HC nerve-activated vestibulospinal neurons terminate in the cervical cord and have strong connections with neck motoneurons.

Animals↗

PubMed2004

The management of possible fishbone ingestion.

OBJECTIVE: We assessed the usefulness of computed tomography (CT) in cases of suspected impaction of fish bones in the esophagus. The findings of this study were also compared with those of studies in which surgery was used to remove or confirm the presence of fish bones. We accordingly propose a management protocol to ensure optimum outcome for patients with a history of fish bone ingestion. METHODS: X-ray and CT imaging were performed in 76 patients in whom esophageal impaction of fish bones was suspected. RESULTS: Plain X-ray revealed impacted fish bones in 17 patients (22%), soft-tissue swelling but no evidence of foreign body in 5 (7%), and no abnormal findings in 54 (71%). These findings were apparent on CT scans in 31 (41%), 8 (10%), and 37 (49%), respectively. Of the 31 patients in whom CT revealed a fishbone, 17 (55%) also exhibited X-ray evidence of foreign body. Of the remainder, X-ray revealed only soft-tissue swelling in 3 (10%), and was unremarkable in 11 (35%). Among the 5 patients in whom X-ray demonstrated only soft-tissue swelling, CT was positive for foreign body in 3 (60%). Of the 54 patients in whom X-ray appearances were normal, CT revealed foreign bodies in 11 (20%) and other abnormalities in 6 (11%). CONCLUSION: In the present study, sensitivity and specificity of plain X-ray was 54.8% (17 of 31) and 100% (45 of 45), respectively. However, for CT, both sensitivity and specificity were 100%. CT was determined to be very useful in the diagnosis of impacted fish bones in the esophagus.

Algorithms↗

PubMed2004

Abnormalities of the electrogastrogram in globus pharyngeus.

There appear to be multiple indicators for the presence of globus pharyngeus. We have assumed that patients with abnormal gastric motility can be included among those suffering from globus pharyngeus. Gastric motility can be examined non-invasively using the electrogastrogram (EGG). In this study, 32 patients (22 females, 10 males; mean age 55+/-13 years) with symptoms of globus pharyngeus consented to EGG recording. The EGGs of asymptomatic healthy adults (6 females, 10 males; mean age 28+/-5 years) were obtained as controls. No significant statistical difference was found in any of the measurement parameters between the two groups. However, we found that 9.4% of patients with globus pharyngeus exhibited abnormal gastric myoelectrical activity as measured by the EGG. This suggests that a small proportion of patients who complain of globus pharyngeus have abnormal gastric motility.

Adult↗

PubMed2004

Identification of beta-tubulin isoform V as an autoantigen in allergic rhinitis by a proteomic approach.

Autoantibodies to IgE and beta2-adrenergic receptor have been reported in patients with allergic rhinitis. To investigate whether autoimmunity in allergic rhinitis is directed to such limited molecules or directed to a wide range of self proteins, we here attempted to survey autoantigens/autoantibodies comprehensively, using proteomics. Specifically, we separated proteins extracted from peripheral blood mononuclear cells by 2-dimensional electrophoresis and then detected autoantigens by subsequent western blotting with sera from patients with allergic rhinitis. As a result, we detected multiple autoantigens, some of which were further identified by mass fingerprinting. Next, we confirmed antigenicity of one of the identified autoantigens, beta-tubulin isoform V (beta-tubV), using a recombinant protein and then measured prevalence of the anti-beta-tubV autoantibodies. As a result, 52% of the tested patients with allergic rhinitis were found to possess anti-beta-tubV autoantibodies. Our study indicates that autoimmunity is a common phenomena and beta-tubV is one of the major autoantigens in allergic rhinitis.

Adult↗

PubMed2004

[Clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis].

The clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis was evaluated. A bipolar radiofrequency system (CelonLab ENT) was used to treat 16 patients suffering from allergic rhinitis between February 2003 and August 2003. The thermotherapy was performed under local anesthesia at the otolaryngology outpatient clinic of St. Marianna University Toyoko Hospital. Data were collected by questionnaire and rhinomanometry preoperatively and 2 months postoperatively. The mean visual analogue scale (VAS) score for intraoperative pain was 31 mm (range, 0-100), and nearly all the patients felt no or a subtle pain during the thermotherapy. Postoperative pain was also well tolerated, with nearly all the patients not requiring analgesic drugs. Postoperative bleeding was minor, and none of the patients required additional treatment for bleeding. Nearly all the patients reported an improvement in their nasal patency, rhinorrhea, headaches, and sleeping. Statistically significant improvements were observed for all the measured VAS scores: nasal patency, rhinorrhea, headache, and olfactory function. Nasal resistance, as measured by anterior rhinomanometry, significantly improved after treatment. The effect of decongestion was also measured using anterior rhinomanometry. The ratio of nasal resistance before and after decongestion was significantly higher after thermotherapy, suggesting that nasal decongestion had a smaller effect on nasal patency after treatment. The current results suggest that the CelonLab ENT device is an effective and safe treatment for allergic rhinitis.

Adolescent↗

PubMed2003

Adaptive plasticity in the otolith-ocular reflex.

This review focuses on the plasticity in the vestibulo-ocular reflex (VOR), especially in the otolith-ocular reflex (OOR). The VOR is a mechanism for the production of rapid compensatory eye movements during head movements. The VOR is under adaptive control which corrects VOR performance when visual-vestibular mismatch arises during head movements. It has been demonstrated that chronic exposure to certain visual environments, those generated by magnifying lenses and reversing prisms, alter the gain and phase of VOR in the dark in numerous species. Most experiments concerning such modification of the VOR have used semicircular canal stimulation. The VOR consists of the semicircular-ocular reflex (ScOR) and the OOR. There are few results regarding the relationship between the gain of the ScOR and the OOR. This review summarizes the studies on plasticity in the OOR. In addition, the difficulty in evaluating the OOR using current conventional methods including earth horizontal axis (EHA) rotation, off-vertical axis rotation (OVAR) and linear sled, is discussed. We believe that the ScOR and the OOR share common neural pathways in such a way that a change in the synaptic efficacy of one pathway is accompanied by a change in the other.

Animals↗

PubMed2003

Wallenberg's syndrome: neurotological classification.

OBJECTIVES: Visually induced eye movements were investigated in 26 patients with Wallenberg's syndrome. METHODS: Slow-phase optokinetic nystagmus (OKN) velocities, pursuit gains, and percentage fixation suppression (%FS) of caloric nystagmus were recorded by DC electrooculography (EOG), and stored directly onto FM magnetic tape. RESULTS: OKN velocities, pursuit gains, and %FS decreased toward the lesion side (group A), whereas OKN velocities and pursuit gains decreased toward the side contralateral to the lesion side. %FS decreased toward the lesion side (group B). MR images in group A showed that lesions were only in and near to the vestibular nuclei, and images in group B showed that lesions extended to the cerebellum. CONCLUSION: Visually guided eye movements allow classification of Wallenberg's syndrome into two types, one with brainstem lesions and one with both brainstem and cerebellar lesions. This demonstrates that assessing eye movements is helpful in supplementing MRI data.

Adult↗

PubMed2003

Saccadic adaptation in the horizontal and vertical directions in normal subjects.

We studied the properties of adaptive gain control in the saccadic system and examined whether the adaptations in the horizontal direction transferred to those in the vertical direction, and vice versa, in 16 normal subjects. Eye movements were measured using search coil system. In the adaptive session, a target moved randomly in amplitude steps of 20 degrees or 30 degrees, with half of the subjects performing in the horizontal direction and the others in the vertical direction. The target eccentricity was changed by a constant percentage (70%) during each saccade aimed at the target. Gains were gradually decreased during the course of 120 repetitions, and then approached approximately 70%. Comparison was made of the accuracy (saccadic amplitude/first target step amplitude) of horizontal and vertical vectors of oblique saccades before and after the adaptation. After the horizontal adaptation, the accuracy of horizontal vectors decreased in the horizontal direction (P<0.05) but not in the vertical direction. After the vertical adaptation, however, the accuracy of horizontal and vertical vectors did not decrease. Our data show that adaptive gain control in the horizontal direction might not transfer to that in the vertical direction, nor vice versa.

Adult↗

PubMed2003

End-to-end anastomosis in chronic tracheal stenosis.

OBJECTIVE: This study assessed the efficacy and safety of end-to-end anastomosis of the trachea following segmental resection in chronic tracheal stenosis. METHODS: End-to-end anastomoses of the trachea were performed in 35 patients with chronic tracheal stenosis; 18 patients with tracheal invasion of thyroid cancer and 17 patients with long-term intubation and blunt injuries of the trachea. RESULTS: All operations were successful, except one whose unilateral recurrent nerve had not been identified in the recurrent thyroid cancer invasion with trachea. CONCLUSION: This operation provides a one-step cure for the stenosed trachea and can be applied to the resection of less than six tracheal segments.

Adenocarcinoma↗

PubMed2003

A case of large dermoid cyst in the floor of the mouth.

Dermoid cysts in the floor of the mouth are rarely observed. When they develop, they do not appear until they grow large enough or appear through infection. Some operative approaches and management have been performed to large dermoid cysts in the floor of the mouth with some variations. Intra-oral approach is the most useful for cosmetic appearance. We presented a 24-year-old female who underwent expedient surgical excision using finger end serviceable enucleation through the intra-oral approach.

Adult↗

PubMed2003

Horizontal eye response to an abrupt lateral head drop in normal subjects and patients with Meniere's disease.

OBJECTIVE: To detect the endolymphatic hydrops by using the otolithic nature in patients with Meniere's disease and delayed hydrops. METHODS: We developed a new technique for measuring horizontal eye movements, corresponding to lateral head drop in total darkness, approximately 1g environment. Normal subjects (n=16, mean age: 27.3 years old) and patients (seven for pre-operative state, four for furosemide test at pre-operative state; two for post-operative state) were employed in the test. The principle of the test is to drop the head in a lateral position separately from the body with a rapid release exposing the head. Bitemporal EOG, accelometric and trigger signals for the releaser were recorded for processing at 1 KHz sampling time. RESULTS: The drop was performed five times in succession. The latency of horizontal eye response was of 40 ms order in normal subjects on both sides and were never beyond 60 ms. Eye response of the patients was in different patterns from normal subjects and the latencies delayed either to normal side or to the affected side. Following furosemide intravenous injection, more certain information was obtained. Three of four patients were recovered to normal range as to the latency. CONCLUSIONS: We emphasize that this test may provide a new measure sensitive to the hydrops and can underline this test to detect the hydrops in Meniere's disease.

Adult↗