Biomedical subjects

Maki Kimura

Publications and source records attributed to Maki Kimura.

8 recordsLinked to original sources

PubMed2006

Pathological localization of so-called posterior canal BPPV.

OBJECTIVE: Based on the hypothesis that the origin of nystagmus is from the posterior canal (PC), the nystagmus in the head hanging and sitting position should be mirror images. To clarify the anatomical origin of positioning nystagmus in BPPV patients, we analyzed the positioning nystagmus of benign paroxysmal positioning vertigo (BPPV) patients three-dimensionally. METHODS: Twenty-six patients with BPPV participated in this study. The positioning nystagmus was recorded in complete darkness from the patient's left eye by means of an infrared CCD camera. We performed three-dimensional analysis of nystagmus using video image analysis system (VIAS). Subsequently, the rotation axis of the 3D eye movements of the positioning nystagmus was calculated. RESULTS: Among the 26 patients tested, 20 patients demonstrated the axes of nystagmus in good or relatively good alignment to the PC axis. However, in 11 of these 20 patients there was poor alignment of the axis of nystagmus in the sitting position to the PC axis. In addition, six patients showed axes of nystagmus with poor alignment to the PC in the head hanging position. Among them, two patients exhibited axes of nystagmus in good alignment with the anterior canal, in spite of diagnosis of these patients as PC BPPV by experienced examiner based on the positioning nystagmus test. CONCLUSION: These results demonstrated that only one-third of patients who were diagnosed as BPPV, could be diagnosed as true BPPV which originates from a PC pathology. Besides the possibility that the pathology may originate from the AC, it is still unclear which part of the inner ear may be the candidate site of origin of the pathology of BPPV in the other 15 patients.

Adult↗

PubMed2005

Three-dimensional analysis of eye movements using four times high-speed video camera.

In order to record and analyze the rapid eye movement non-invasively in human subjects, a four times high-speed video camera (4TC) with a new computer software was developed and utilized. Nine healthy volunteers and four patients with vestibular dysfunction participated in this study. Caloric stimulation was applied to the healthy subjects and the eye movements were recorded using a standard camera (SC) and a 4TC. In four patients, the positional and/or positioning nystagmus was recorded using SC and 4TC. Analysis of the eye speed of the quick phase of nystagmus was performed manually from the print out of the chart. The quick phase of the caloric nystagmus was adequately analyzed from the data using 4TC. However, using SC the sampling rate was not sufficiently enough for this purpose, as prospected. The adaptability of the 4TC in clinical examination is exactly similar to that of SC, because of the size and weight of the camera. Although the time taken to analyze eye movements using 4TC is about four times longer than that using SC, this system is quite useful and adequate for analyzing the quick eye movements in vestibular nystagmus, in an out-patient clinic set up.

Adult↗

PubMed2004

Randomized controlled trial of sour milk on blood pressure in borderline hypertensive men.

BACKGROUND: A double-blind randomized controlled trial was carried out to assess the effect of sour milk, containing two tripeptides (valine-proline-proline and isoleucine-proline-proline), on blood pressure (BP). METHODS: A total of 46 borderline hypertensive men aged 23 to 59 years were recruited at their workplace for this trial. Subjects were randomly allocated into two groups; sour milk drink group (S-group, n = 23) and placebo (acidified milk) drink group (P-group, n = 23) for 4 weeks. Blood pressure was measured twice at each occasion by a physician, at the health center of the company, with a mercury at baseline, 2 and 4 weeks. Statistical analysis was performed by SPSS 10.0J. RESULTS: The S-group and P-group showed no significant difference in baseline systolic BP (mean [SD], S: 147.6 [9.6], P: 145.3 [13.0]) or diastolic BP (S: 95.3 [9.9], P: 91.5 [9.6]). In the S-group, change in systolic BP at 2 and 4 weeks were -4.3 mm Hg (95% confidence interval [CI] -8.3 to -0.4; P = .032) and -5.2 mm Hg (95% CI -10.1 to -0.3; P = .039), both statistically significant. Diastolic BP showed change from -1.7 mm Hg (95% CI -5.4 to 2.0) at 2 weeks and -2.0 (95% CI -5.4 to 1.5) at 4 weeks, respectively. In the P-group, change in systolic BP were -0.5 (95% CI -5.8 to 4.8) at 2 weeks and -3.7 (95% CI -8.3 to 0.9) and change in diastolic BP were -0.6 (95% CI -4.7 to 3.6) and -0.3 (95% CI -3.9 to 3.3), which were not statistically significant. CONCLUSIONS: This trial demonstrated the beneficial effect of sour milk on BP in borderline hypertensive men who were not taking antihypertensive medication.

Adult↗

PubMed2004

A head-mounted visual stimulator for neurotological examination.

OBJECTIVES: Presently, the neurotological tests, using visual stimulation, such as optokinetic nystagmus test (OKN), eye-tracking test (ETT) is being widely used for the diagnosis of vertigo or disequilibrium. The problems of these tests are the large size of the visual stimulator and therefore a wide space requirement. Even if a small apparatus is developed, the apparatus itself would be very expensive. In this study, we developed a small visual stimulation test system comprising the virtual visor, which receives an image for visual stimulation from an on-line computer. METHODS: Using smooth pursuit and optokinetic stimulation onto a virtual visor we assessed the ENG recording in 20 normal subjects. RESULT: We found the 30 degrees /s OKN, horizontal eye tracking were adequately stimulated by this technique with reliable results. CONCLUSION: This new method of smooth pursuit and optokinetic stimulating by a virtual visor is capable of producing reliable results and may be used in the clinical laboratory of vertigo. However, this stimulator also has some limitations, mainly because of the visual angle of the virtual visor stimulator.

Adolescent↗

PubMed2004

Subcutaneous emphysema after tonsillectomy: a case report.

We experienced a case of a subcutaneous emphysema after tonsillectomy. The patient, a 24-year-old man, complained of a recurrent sore throat and was diagnosed as having chronic tonsillitis. Pre-operative general examinations revealed no abnormalities. The operation was carried out under general anesthesia. The adhesions between the tonsils and the surrounding tissues were moderate. The bi-lateral tonsils were easily removed. The recovery period was uneventful. On the next morning, marked swelling of the left cheek and submandibular area was noted. On palpation, there was a characteristic crepitation and softness in these areas. The X-ray examination revealed subcutaneous emphysema. There was no finding of airway obstruction. We diagnosed him as having a subcutaneous emphysema and administered antibiotics for 5 days. From clinical findings, the subcutaneous emphysema was thought to be caused by surgical rather than anesthetic factors. The subcutaneous emphysema gradually disappeared. One year after the tonsillectomy, the patient is under observation as an outpatient and is free from any abnormal symptoms. To avoid this kind of complication, we should pay attention to carefully separate the tonsil from its fossa and to make appropriate selection of surgical equipments.

Adult↗

PubMed2003

The effect of gravity on the stability of human eye orientation.

OBJECTIVE: The stabilization of both the horizontal (H) and vertical (V) eye movements during voluntary fixation is believed to depend upon the visual feedback system in the upright position. However, ocular stability in the tilted position has been less well investigated. Therefore, in the present study, we examined the gaze stability of healthy human subjects in the three dimensions in the tilted position using a video image analysis system (VIAS). METHODS: In 10 healthy human subjects, the eye movements were recorded after fixating the eye on a target in an upright position and also in the tilted position. The standard deviations of the eye movements in the three dimensions were calculated to evaluate the stability of the movements. RESULTS: In the tilted position, there were no significant changes in the horizontal and vertical eye movements as compared those in the upright position. However, the standard deviation of the torsional (T) segment was significantly larger in the tilted position, compared to that in the upright position. CONCLUSION: From these results, we speculate that, a combination of otolith and somatosensory inputs play a major role in maintaining the stability of eye movements.

Adult↗

PubMed2003

Traumatic perilymph fistula in infants: a case report.

Traumatic perilymph fistula is reported to be rare in infants because of the small size of the infant external meatus. We treated an infant with a traumatic perilymph fistula in the right ear. A metallic wire had penetrated the tympanic membrane. Horizontal-rotatory nystagmus was also observed. Computed tomographic images revealed dislocation of the ossicles. The perilymph fistula was closed under general anesthesia. The incus-stapes joint was separated and the footplate of the stapes was dislocated. Leakage of the perilymph fluid was apparent from the oval window and this fistula was closed with connective tissue. The perforation of the tympanic membrane was closed with temporal fascia. After surgery, the spontaneous nystagmus disappeared. The patient is under observation as an outpatient and is growing normally.

Child, Preschool↗

PubMed2002

Baclofen is neuroprotective and prevents loss of calcium/calmodulin-dependent protein kinase II immunoreactivity in the ischemic gerbil hippocampus.

Excessive release of glutamate during transient cerebral ischemia initiates a cascade of events that leads to the delayed and selective death of neurons located in the hippocampus. Activity of calcium calmodulin kinase II (CaM kinase), a protein kinase critical to neuronal functioning, disappears following ischemia. The in vivo link between glutamate excitoxicity and alterations in CaM kinase activity has not been extensively studied. Baclofen, a selective gamma-aminobutyric acid (GABA)(B) receptor agonist, has been shown to inhibit glutamate release. The present study evaluated the neuroprotective efficacy of this compound and assessed early changes in hippocampal-dependent behaviors and CaM kinase immunoreactivity following transient cerebral ischemia. Baclofen (50 mg/kg) prevented both the loss of hippocampal CA1 pyramidal cells and the reduction in hippocampal CaM kinase immunoreactivity observed in control animals following ischemic insult. Cerebral ischemia produced a significant increase in working memory errors; however, baclofen failed to attenuate this memory deficit. Results confirm that baclofen is neuroprotective and support a link between glutamate excitotoxicity and reductions in CaM kinase immunoreactivity.

Animals↗