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Biomedical subjects

N Saeki

Publications and source records attributed to N Saeki.

At least 19 recordsLinked to original sources
PubMed1994

Three-dimensional audiogram.

We used a three-dimensional audiogram which displays duration of the disease on the X-axis, frequency on the Y-axis, and hearing level on the Z-axis, to aid observation of hearing changes during the course of various otologic diseases. An overall, quantitative view of the changes in a patient's hearing level with time was easily obtainable with this technique, as the temporal element is shown on the X-axis. The basal view position of the three-dimensional audiogram displays most of the information necessary to form a diagnosis, determine treatment, and evaluate is efficacy in various otologic diseases. The three-dimensional audiogram was found to be most useful in observing changes in hearing level in sudden deafness, with its often rapid recovery period, and Meniere's disease, with its long-term fluctuating hearing loss. In some patients, a better understanding of the hearing changes could be obtained from a view angle other than the basal view position.

Adult↗
PubMed1994

Assessment of prognosis in sudden deafness.

We investigated the usefulness of three-dimensional audiograms in assessing prognosis during the early phase in 116 patients with sudden deafness. The initiation time of improvement in middle-frequency hearing at 15 dB or more was valuable in assessing prognosis in patients with deafness and scale-out types of hearing loss. Improvement within 13 days in patients with the deafness type, and within 17 days in those with the scale-out type, was correlated with a high incidence of marked improvement or complete recovery. Patients with an initial mean hearing level below 80 dB, or in whom the glycerol test and electrocochleography results suggested the presence of endolymphatic hydrops, had a good hearing outcome. Patients without tinnitus showed an unfavorable hearing outcome.

Adult↗
PubMed1994

[Microsurgical anatomy of the anterior communicating artery and its perforating arteries important for interhemispheric trans-lamina terminalis approach: analysis based on cadaver brains].

Microsurgical anatomy of anterior communicating artery (ACoA) and its perforating arteries important for interhemispheric trans-lamina terminalis approach is examined in 25 cadaver brains under magnification using a surgical microscope. ACoA were found in all cases but 60% of those cases had variations such as plexiform ACoA, dimple ACoA, fenestrated ACoA, triple A2 and azygous ACA. In cases with variations such as plexiform ACoA, triple A2 and azygous ACA, it seems difficult to section and divide the ACoA to obtain a better operative field. Perforating arteries of ACoA were noted in all cases. They were classified into the subcallosal artery, hypothalamic artery and chiasmatic artery according to caliber, origin, course and termination. Among these three arteries, subcallosal artery is thought to be an offending artery in memory impairment, character change and psychological abnormalities, because it terminates at the bilateral subcallosal areas. We stress in this paper that the subcallosal artery is the most important perforating artery of ACoA and the incidence of variations of ACoA is higher than previously reported.

Aged↗
PubMed1992

[Oculomotor nerve palsy due to small midbrain infarct--functional topography based on MRI findings].

This is a report of 3 cases presented with oculomotor nerve palsy caused by small midbrain infarct. The aim of this report is to clarify the functional topography of intranuclear and intrafascicular portion of the oculomotor nerve with MRI. Three cases are 2 males and 1 female, ranging 51 to 68 years in age. Except for the long tract signs at the acute stage, cardinal sings were all eye-related, incomplete in 1 case and pupil sparing-type in 2 cases. In MRI, the size of the lesion extended 5 to 12 mm. In the incomplete palsy case, the infarction extended from the level immediately below the 3rd ventricle into the whole length of midbrain, whereas in the pupil-sparing types, more limited lesion excluding the upper part of the midbrain was noted. Anatomically the longitudinal size of the nucleus is 10mm and nerves functionally related to pupil reaction, eye motion and eyelid elevation are arranged in rosrocaudal order. Therefore, it is speculated that in midbrain, intrafascicular location of nerve fibers associated with pupil reaction is rostral and oculomotor nerve palsy of pupil sparing type is caused by the lesion excluding the rostral midbrain. MRI findings of the present 3 cases are compatible with this speculation. The lowest border of red nucleus is at the level of superior colliculus, whereas oculomotor nucleus has its lowest margin at the inferior colliculus. Therefore, red nucleus becomes an informative landmark to visualized the level of oculomotor nerve injury, since the red nucleus is clearly demonstrated in high intensity in T2 weighted image.

Aged↗
PubMed1991

[Simple allergen skin test device Multi skit (tentative name)].

We have developed a device tentatively named Multi Skit (Mu), a simple allergen test device, in order to conduct the skin test safely, accurately and conveniently. The utility of this device was evaluated by determining how the results obtained by the intradermal test (In) and Mu were correlated with those obtained by IgE RAST (RA) in 65 AD patients. RA values concerning nine antigens were compared to results obtained by the In and Mu in terms of the positive and negative response coincidence rates, overall coincidence rates, and false-positive and false-negative response rates. The correlation between RA data obtained from the literature and the results of the scratch test (Sc) was also evaluated. The results of In and RAST values showed no correlation regardless of the food antigen used. Mu and RAST values showed correlation with respect to all 4 food antigens except soy-bean, resulting in overall coincidence rates of 66.2 to 87.7%, which were higher than those concerning the Sc. With respect to false-positive responses to environmental antigens, the rate obtained by Mu was higher than that by the Sc, but it was lower than that by the In. However, Mu was the most excellent test with respect to the other indices, i.e., positive and negative response coincidence rates, overall coincidence rates (73.9-89.2%) and false-negative responses. The mechanism of Mu makers it possible to minimize variations from one investigator to another, and the major drawback of all other skin tests. Mu is a safe and convenient screening skin test device which provides accurate and specific test results.

Adolescent↗
PubMed1991

[Hemorrhagic type of moyamoya disease].

Clinical picture of Moya Moya Disease was analyzed in 18 cases. In 16 cases whose CT scan were available at the time of the first bleeding, hematoma at the basal ganglia was noted in 43.8%, primary ventricular hemorrhage in 37.5%, thalamic hemorrhage with ventricular rupture in 12.5% and subcortical hemorrhage in 6.3%. The frequencies shown above were well correlated to previous reports. In MRI performed 1 year or more after primary ventricular hemorrhage, the primary bleeding site was demonstrated at the lateral wall of the lateral ventricle, in proton weighted and T2 weighted images. MRI can detect the site of old bleeding points and its chronological change if the study is repeated. In a follow-up period of 5.4 years, 27.8% of the cases had rebleeding one or more times. As a result, good outcome was noted in 72.2% after the 1st bleeding, and in 55.6% after re-bleedings. Death occurred in 5.6% of patients after the 1st bleeding and in 22.2% after further rebleeding. Rebleeding worsened the outcome. Therefore, prevention of rebleeding is important. From a therapeutic viewpoint, although a direct relation between rebleeding and untreated hypertension could not be established, blood pressure control is critical at both the acute and the chronic stages. Reconstructive vascular surgery is a recommendable method for properly selected patients.

Adult↗
PubMed1990

Movement of vesicles in cytoplasmic streaming in plasmodium.

The moving velocities of vesicles in the cytoplasmic streaming of a slime mold were measured, in which all of the vesicles passing through a designated window were counted. Vesicles in the streaming are distributed in their moving velocities and the distribution itself varies with time. The mean velocity of vesicles and its standard deviation were found to exhibit a linear relationship, suggesting a possibility that vesicles in the cytoplasm would also be involved in force generation.

Cytoplasmic Streaming↗
PubMed1990

Dissecting aneurysms of the intracranial vertebral artery.

Among 86 patients with aneurysms arising from the vertebral artery or its branches, 24 had dissecting aneurysms. The patients with dissecting aneurysms were characteristically relatively young males. Twenty-one patients presented with subarachnoid hemorrhage (SAH) and three with ischemia. Severe headache or neck pain occurred in all three patients with ischemia. Five of the 21 patients with SAH and all three patients with ischemia experienced recurrent episodes. Angiography typically showed fusiform dilatation and proximal and/or distal narrowing of the affected artery. The difficulty of diagnosing this disorder is pointed out. Surgery was performed in 19 patients, the most common technique being clip-occlusion of the proximal vertebral artery. There were no postoperative deaths or rebleeding; a lateral medullary syndrome developed in three patients. The observation at surgery of intramural clot with characteristic discoloration was limited to the cases operated on within 36 days after the ictus. After this period, the aneurysm was whitish gray in color and had become firm. Of 36 other cases of vertebral dissecting aneurysm reported in the literature, 20 were operated on. The indications for surgery are discussed.

Adult↗
PubMed1990

[One and a half syndrome and MRI--a case report and functional neuroanatomy of the syndrome].

This is a case report of 63 year old men who presented one and a half syndrome with ipsilateral peripheral type facial palsy due to lacunar infarct. MRI taken one week after the onset (TR 2000, TE 38) demonstrated small high intensity lesion, 4 mm in diameter, located at the dorsal portion of pontine tegmentum, contacting with the floor of 4th ventricle. This MRI coincides with the lesion limited to the abducens nucleus and genu of facial nerve. Traditionally, projections from the PPRF to the ipsilateral abducens nucleus and opposite MLF was postulated. Recently, however, experiment on monkey and autopsy cases showed projection from abducens nucleus, instead of PPRF, to the opposite MLF has been proposed. MRI findings in this case support the latter hypothesis. It is expected that, with the advent of MRI, more meticulous functional neuroanatomy will be developed.

Dementia, Multi-Infarct↗
PubMed1990

[Intravenous DSA as a screening method for cerebral aneurysms].

Intravenous DSA (IVDSA) was evaluated as a screening method for cerebral aneurysms. It was performed 390 times in 372 cases. Clinically useful images were obtained in 94.1% in all examinations. Nineteen aneurysms were visualized in cerebral angiography among 21 cases with SAH or 3rd nerve palsy, whereas in IVDSA 15 aneurysms were noted. Aneurysms not visualized in IVDSA were all 4 mm or less in size. Therefore, aneurysms, more than 4 mm in size, which have higher risks for rupture, were detectable in IVDSA. Based on these findings, IVDSA is considered to be clinically useful in screening for aneurysms. In all 372 cases, 33 aneurysms were suspected in IVDSA findings, whereas in cerebral angiography 21 of them turned to be aneurysms. Such 12 false positive cases were distributed mainly at anterior communicating and middle cerebral arteries. Improvement of image resolution, avoidance of vessel overlapping and proper selection of screened cases should be investigated for further development of this screening method.

Angiography, Digital Subtraction↗
PubMed1989

Post-traumatic intention tremor--clinical features and CT findings.

Eight patients with post-traumatic intention tremor were reported. Intention tremor developed in the young as a late complication of severe head injury (Glasgow Coma Scale was below 8 in all cases) and impaired their functional outcome. This state was treatable with medication or by stereotactic thalamotomy. Neurologically, all the patients lapsed into coma immediately after the injury and many patients manifested clinical signs of a midbrain lesion in the chronic stage. The characteristic CT (computed tomography) findings in the acute stage were a high density area in the midbrain, accompanied by diffuse cerebral swelling or intraventricular hemorrhage, and in the chronic stage, brain atrophy or ventricular enlargement were the most prominent CT findings. These characteristics, indicating diffuse brain damage in addition to midbrain injury, may suggest the presence of shearing injury. The midbrain damage is consistent with the classical hypothesis that the damage to the Dentate-Rubro-thalamic system accounts for the occurrence of intention tremor. Furthermore, the presence of diffuse brain damage suggests that a more widespread brain injury may participate in its development.

Adolescent↗
PubMed1989

[Intention tremor after head injury. Clinical features and computed tomographic findings].

Eight cases of intention tremor as a late complication of head injury were investigated. The patients ranged in age from 3 to 24 years. All received severe head injuries and lapsed into coma immediately afterward (Glasgow Coma Scale scores less than or equal to 8). Six patients exhibited decerebration or decortication. Hemiparesis was present in six cases and oculomotor nerve palsy in four. In the chronic stage, all patients displayed some degree of impairment of higher cortical function and five had dysarthria and/or ataxia. Initial computed tomography (CT) scans within 3 hours after the injury were obtained in five cases, of which four showed a hemorrhagic lesion in the midbrain or its surroundings. Other CT findings were diffuse cerebral swelling (four cases), intraventricular hemorrhage (three), and multiple hemorrhagic lesions (two). In the chronic stage, generalized cortical atrophy or ventricular enlargement was noted in five cases. These clinical features and CT findings indicate diffuse brain damage as well as midbrain damage and may reflect shearing injury.

Adolescent↗
PubMed1989

[Umbilical blood-gas status at cesarean section for breech presentation: a comparison with vertex presentation].

Umbilical blood-gas status at elective cesarean section with oxygen inhalation for breech presentation (25 cases) was compared with that for vertex presentation (25 cases), so as to confirm the security of full-term breech fetuses delivered by cesarean section under spinal anesthesia. Umbilical arterial oxygen levels were significantly lower in the breech group (Mean PO2:18.9 mmHg; SO2:37.3%; Oxygen content:7.6 ml/dl). The number of hypoxemic fetuses was significantly higher in the breech group (the breech: 7; the vertex; 0). The other umbilical blood-gas values revealed no significant differences between the breech and vertex groups, and were within normal limits in both groups. Oxygen extraction in the breech (Mean: 49.0%) was higher than that in the vertex (32.9%). Therefore decreased umbilical blood flow in the breech was suggested. The incidence of depression at 1 minute after delivery in the breech infants (24%) was significantly higher than that in the vertex infants (0%). It became obvious in the breech that as the interval between the uterine incision and delivery increased, umbilical arterial blood tended to acidosis and the 1 minute Apgar score decreased. Cesarean section for breech presentation requires sufficient and optimal incisions of the abdominal wall and uterus as well as a skillful manual delivery technique, because the fetus or neonate should be protected against asphyxia resulting from umbilical compression and prolonged delivery interval.

Adult↗
PubMed1988

[Effects of maternal hyperventilation and oxygen inhalation during labor on fetal blood-gas status].

The effects of maternal hyperventilation and oxygen inhalation on fetal blood-gas status were studied in 54 fetuses, vaginally delivered of mothers without medical and obstetrical complications. The cases were divided into four groups according to MA (maternal arterial) pH and PCO2 values and by respiring either oxygen or room-air as follows. Group N: pH less than 7.5, PCO2 greater than 23 mmHg (normoventilation), without maternal oxygen inhalation, group H: pH greater than 7.5, PCO2 less than 23 mmHg (hyperventilation), without oxygen inhalation, group NO: pH less than 7.5, PCO2 greater than 23 mmHg, with oxygen inhalation and group HO: pH greater than 7.5, PCO2 less than 23 mmHg, with oxygen inhalation. Umbilical venous (UV) PO2 (27.8 mmHg: mean), SO2 (60.8%) and CO2 (oxygen content, 12.4 ml/dl), and umbilical arterial (UA) PO2 (17.9 mmHg), SO2 (35.6%) and CO2 (7.3 ml/dl) values in group H were significantly lower than those in group N. The fetal oxygenation in group HO was similar to that in group N, and the fetal oxygen values in group NO were significantly higher than those in the other groups. The fetuses in groups H and HO tended to respiratory alkalosis. The UV oxygen values had negative correlations with MA pH and positive correlations with the MA PCO2 value in both oxygen and no-oxygen groups. There was no significant correlation between maternal and fetal PCO2 values, and higher fetal oxygen extraction (41%: mean) in group H. These facts suggest that severe maternal respiratory alkalosis due to hyperventilation may lead to a disorder in placental circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗