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Biomedical subjects

H Iseki

Publications and source records attributed to H Iseki.

At least 73 records · Page 4Linked to original sources
PubMed1988

Degenerative changes of primary neurons following tooth extraction.

In summarizing the present experimental results of tooth extraction, it can be emphasized that the disturbance of the sensory input units from the teeth resulted in a definite degeneration of the primary neurons. On this ground, it is suggested that the lesion of the sensory input units in the masticatory computer system, according to the individual age affected, may become a large factor in impeding the masticatory activity and accelerating the aging of the masticatory function.

Animals↗
PubMed1987

Surgical treatment of hypertensive intracerebral haematoma by CT-guided stereotactic surgery.

Ninety consecutive cases of hypertensive intracerebral haematoma were treated with CT guided stereotactic evacuation. The patients were composed of 61 males and 29 females, ranging from 42 to 87 years old. The location of haematoma was either in the putamen (59 cases) or in the thalamus (31 cases). The average volume of the evacuated haematoma was 21.4 ml in the putaminal haematoma and 14.0 ml in the thalamic haematoma. Postoperative follow-up study in 46 patients showed good recovery of neurological deficits both in putaminal and thalamic group. Criteria of surgical indication of CT-guided stereotactic evaluation of intracerebral haematoma were advocated based on the author's clinical experience.

Adult↗
PubMed1987

Short latency somatosensory-evoked potentials--direct recording from the human midbrain and thalamus.

Short latency somatosensory-evoked potentials were recorded from the human thalamus and the midbrain during stereotactic operations. Several subcomponents were recognized on the peak of N18. These were recorded with maximal amplitude at the border between the caudal portion of the thalamus and the rostral midbrain. Two positive-negative responses, not previously shown, were observed between P14 and N18. These responses were prominent in the rostral midbrain. These findings indicate that the ascending phase of N18, and the N18 itself, are the compound potential generated in the mesodiencephalic junction.

Brain Mapping↗
PubMed1987

[CT-guided stereotactic brachytherapy in deep-seated malignant gliomas--interstitial irradiation by double-catheter after-loading method].

CT-guided stereotactic brachytherapy has been performed for the deep-seated malignant gliomas using the double-catheter after-loading method. The catheter system consists of two coaxial polyethylene tubes with closed tips. The outer catheter is 3.0 mm in outer diameter and 2.4 mm in inner diameter. The inner catheter is 2.0 mm in outside diameter and 1.4 mm in inside diameter, and contains the radioactive sources. Localization of the target volume is determined by the preoperative findings of computed tomography (CT), magnetic resonance imaging (MRI), and cerebral angiography. Dosimetry and dose planning are so finalized for the target volume as to be irradiated interstitially more than tumoricidal dose. After stereotactic biopsy of the deep-seated brain tumors, stereotactic implantation of the outer catheters is performed using Iseki Stereotactic System in the CT room. Burr holes had been previously opened in the operating room. The inner catheters containing nonradioactive sources (dummy sources) are inserted, and skull X-p is taken to confirm the position of the dummy sources, and to calculate the dosimetry by computer. The inner catheters are replaced with catheters containing radioactive sources (226Ra) in the irradiation room. 226Ra sources deliver at least 500 rads/day (approximately 20 rads/hr) to the target volume as interstitial irradiation. Two patients of malignant gliomas treated with this procedure were shown as representative cases. These patients underwent CT-guided stereotactic brachytherapy as "boost" combined with conventional external irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Long-term follow-up study of rostral mesencephalic reticulotomy for pain relief--report of 34 cases.

A long-term follow-up study of rostral mesencephalic reticulotomy (RMR) for pain relief is presented. 34 patients (24 males and 10 females) were operated. Ages ranged from 18 to 65 years. The follow-up period was 1-70 months. The overall effectiveness of RMR showed good relief of pain in 23 patients (67%). The study of effectiveness of RMR according to type of pain showed good relief of pain in 5 out of 6 patients (83%) with nondenervation pain, whereas satisfactory pain relief was obtained in 18 out of 28 patients (64%) with denervation pain.

Adolescent↗
PubMed1986

[A new treatment of hypertensive intracerebral hematoma--a follow-up study on 46 patients with hematoma treated by CT guided stereotactic method].

During the last 2 years, 46 cases of hypertensive intracerebral hemorrhage in the basal ganglia were treated by CT guided stereotactic aspiration and their outcome was evaluated in terms of the rate of hematoma removal, the change of consciousness level and the recovery of motor and sensory functions. They are aged from 45 to 79 years old, the average 56, and aspirated 1 to 24 days after the onset, two third of them being within 1 week. The whole procedure was done in the CT room under direct CT guidance and by one trial. In putaminal type hemorrhage, the removed hematoma volumes ranged from 9 to 48 ml, average being 23.7 ml, in thalamic type from 5 to 29 ml, average being 15.5 ml. The average rate of removal was 81.1% in 30 cases within 1 week. In most cases, preoperative consciousness was not severely disturbed, in putaminal type, 19 were alert or confused, 4 somnolent, 5 stuperous and in thalamic type, 6, 6, 3 respectively and 2 were semicomatous, one of them had herniation sign. In putaminal type all but 2 cases recovered to alert or confused state, the first one had postoperative bleeding and the other was already apallic preoperatively. In thalamic type, we lost 3 cases, 2 by gastrointestinal bleeding and 1 DIC, by rehemorrhage 2 months after the operation. All but one who was semicomatous preoperatively recovered to alertness. In motor function, some cases of the putaminal bleeding with intact internal capsule remained hemiplegic. On the other hand, most of the cases with partial destruction of the internal capsule on CT recovered well in both types of hematoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

[Ascending limb of the N20 component of somatosensory evoked potential--an analysis on direct recording from the human midbrain].

Somatosensory evoked potential elicited by median nerve stimulation at the wrist was recorded from five loci on the trajectory of stereotactic rostral mensencephalic reticulotomy. Four distinct positive waves followed by one negative wave, the peak latency being 16.3 msec, were recorded from the rostral midbrain reticular formation near the medial lemniscus. The four positive waves were named as I, II, III, and IV respectively. Peak latency of these positive waves was 12.6, 13.7, 14.7 and 15.8 msec respectively. The first two positive waves (I, II) corresponded to P13 and P15 recorded over the scalp. The other two positive waves (III, IV) changed their polarity to negative at the level of the ventral thalamus and formed the ascending limb of N20 recorded over the scalp. N16 was most prominent at the level of nucleus ventrocaudalis externus. These findings suggest that the ascending limb of N20 is composed of at least three components, wave III, IV, and N16. The present report is compatible with the investigations by Abbruzzese et al.2) and Eisen et al.11) that there are several distinct dipoles between P15 and N20 of somatosensory evoked potential in man.

Afferent Pathways↗
PubMed1986

[Significance probability mapping of brain electrical activity--its problem and specified z-statistic mapping].

Significance probability mapping (SPM) of brain electrical activity first described by Duffy et al. is useful tool for studying functional aspects of brain disease. Z-statistic SPM is able to identify the area of brain electrical activity deviated with statistic significance from the control group. The problem of this method is, however, that the nature of deviation, i.e., whether it is increase or decrease of electrical activity, can not be displayed. From this point of view, we attempted to use modified z-statistic method. Statistically deviated region and its nature can be clearly displayed on the same picture by analyzing EEG with this method. This method can be applied to SPM of evoked potentials. SPM is not yet complete method for the assessment of brain electrical activity, but there is much room for adopting other statistic method that is more suitable for the aim of the study. Functional aspects of the brain will be more readily clarified by the use of modified SPM and by combination with findings of CT scan, NMR and PET that can give morphological and metabolic information.

Adult↗
PubMed1985

A new apparatus for CT-guided stereotactic surgery.

Combining whole-body CT scan with a stereotactic system, the authors have developed and applied clinically an apparatus which readily provides intraoperative CT images, making it possible to confirm the location of the target point and ascertain the intraoperative environment. It takes about 9 s to obtain a CT image. Our purpose is to make stereotactic surgery, a kind of blind surgery, as safe and reliable as a visualized procedure by intraoperative CT scanning. By the method, in which there is very little invasion under local anesthesia, evacuation of deep-seated intracerebral hematomas as well as brain abscesses and also biopsy or brachytherapy of brain tumors in the brain can be done with safety and reliability.

Cerebral Hemorrhage↗
PubMed1985

CT-guided stereotactic surgery for evacuation of hypertensive intracerebral hematoma.

During the last 3 years, 46 cases of hypertensive intracerebral hemorrhage were treated by CT-guided stereotactic surgery. Our present report is concerned with the evaluation of this procedure in the treatment of hypertensive intracerebral hematoma, in terms of the rate of aspirated hematoma and follow-up study of patients. It is difficult to draw any definite conclusion about the operative indications. CT-guided stereotactic aspiration, however, can be evaluated as a less invasive and more definitive treatment of intracerebral hematoma in the basal ganglia and thalamus.

Aged↗
PubMed1985

Ultrastructural changes of neuromuscular receptor organs in the masseter muscles following unilateral transection of the rat infraorbital nerve.

Definite ultrastructural changes of the neuromuscular receptor organs were demonstrated in the young and adult rat masseter muscles either on the operated or unoperated side following the unilateral transection of the infraorbital nerve. The grade of the degeneration was intensive but quite similar in having no relation to the age of the rat when the operation was performed, while it increased drastically with time after the operation. On this base, it may be suggested that the sensory input coming from the various kinds of sensory receptors in the snout field do rather affect bilaterally the minor reflexive movements of the jaw. In other words, it can be said that the minor reflexive movements of the jaw might have been controlled by the sensory inputs coming from the snout sensory receptor organs. The definitely degenerated changes of the neuromuscular receptor organs in the masseter muscles should be regarded as disuse atrophy following the interception of the snout sensory input.

Animals↗
PubMed1985

[A new apparatus and stereotactic method for percutaneous high cervical cordotomy].

The authors devised a stereotactic apparatus for percutaneous cordotomy based on the experience of 191 percutaneous high cervical cordotomies on 150 patients suffering from intractable pain. This apparatus has two major components. One is a head and neck holder and the other is a guide and marker system. The head and neck holder contains fixed neck holder and head holder which can be movable in vertical direction. Using these holders, the operator can keep the patient's neck in neutral position. The marker system contains two markers of origin and a 10mm scale which indicates center line as well. The guide system, stereotactically designed, is movable in three direction and acrylic guide groove is attached. The guide needle for percutaneous cordotomy is inserted along the guide groove. The guide and marker system can be attached in both sides of the head and neck holder, therefore, the operator can insert the needle in both sides of the patient. This apparatus makes it possible to locate the target stereotactically for percutaneous cordotomy, since location of the inserted needle can be determined with the aid of cervical X-ray, even if there is no image intensifier of TV display screen available. Therefore it can be possible to reduce the X-ray exposure of the patient.

Cordotomy↗
PubMed1985

[Evaluation of anticonvulsant-induced bone changes by a microdensitometric method].

The effect of long-term anticonvulsants on bone change was evaluated by microdensitometric method (MD method) in 221 outpatients of Neurological Institute Tokyo Women's Medical College. Laboratory findings including serum Ca, P, Al-p were compared with severity of bone change. Following results were obtained; In 221 patients, 159 cases (72%) were normal, 31 cases (14%) were in the initial stage of abnormality, 23 cases (10%) in grade I, 7 cases (3%) in grade II and one case (1%) in grade III of abnormality. Incidence of abnormality was high in the age of 26-35 years old and in the age over 56 years old. Total dose, serum concentration of diphenylhydantoin (DPH) as well as phenobarbital (PB) and also duration of administration of PB correlated positively with severity of bone change. Duration of administration of DPH and valproic acid (VPA), total dose and serum concentration of VPA did not correlate with severity of bone change. Serum Ca correlated with severity of bone change, but P and Al-p did not correlate with severity of bone change. Pattern of bone change was estimated by two parameters of MD method (MCI and GSmax). Results showed that most of the osteopathy (grade I-III by MD method) fell into osteoporotic type. Based on these results, it is suggested that roentgenologic and biochemical supervision of the patients is required during long-term anticonvulsant therapy.

Absorptiometry, Photon↗
PubMed1985

Structural and functional adaptation of the pulpal nerve fibers in the rat incisor.

Special fine structure of the pulpal nerve fibers adapted to the continuously growing incisor was studied on 20 rats (25-d-old-males) electron microscopically and was compared with that of the molars of limited growth. The incisal pulp was innervated by 2 kinds of the nerve fibers derived from the cervical sympathetic and the trigeminal ganglia: polyaxonal unmyelinated and monoaxonal myelinated. In the apical pulp, however, the pulpal nerve fibers were unmyelinated, showing 3 different profiles in the fine structure: 1. polyaxonal, 2. polyaxonal with dial plate-like profile and 3. monoaxonal. The monoaxonal unmyelinated fiber reflected the transverse profile of the unmyelinated part of the myelinated axon derived from the trigeminal ganglion. It can be concluded that the pulpal nerve fibers derived from the trigeminal ganglion maintain the immatured nature in the apical proliferating pulp to adapt to the continuous growth of the incisor.

Animals↗
PubMed1985

[An assessment of outcome prediction in patients with severe brain damage with auditory brainstem response and blink reflex].

Results of auditory brainstem response (ABR) and electrically elicited blink reflex (BR) recorded from 43 patients with severe brain damage within three days after the onset of illness were analyzed to assess the prognostic value of ABR and BR with respect to patient outcome evaluated by the criteria proposed by Jennett and Bond. It was possible to recognize, in recordings obtained from patients with severe brain damage, three basic patterns of BR as well as five patterns of ABR within three days after the onset. Three basic patterns of BR were composed of Type I, which closely approximated the BR of normal subjects except for moderately prolonged latency of R2, Type II, which indicated absence of bilateral R2 activities, and Type III, which showed absence of R1 as well as bilateral R2. ABRs were graded, in increasing order of abnormality, from Type I to Type V. Type I was almost normal pattern from wave I to wave V. Type II indicated prolonged latency or markedly reduced amplitude of waves IV and V. Type III showed absence of waves IV and V. Type IV had only wave I. Type V indicated absence of all waves. BR abnormalities significantly proved useful in predicting vital prognosis of the comatose patients with supratentorial lesion. In patients who had Type II of BR, additional studies of ABR enhanced the reliability of prediction of functional prognosis. On the other hand, ABR was recognized as stronger basis for predicting outcome in patients with infratentorial lesion. All patients with Type IV or Type V of ABR were expired within one month after the onset.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[A case with postoperative calcified epidural hematoma].

In the literature, postoperative calcified epidural hematoma is not common. The authors report a case of calcified epidural hematoma after ventriculoperitoneal shunt, and radiotherapy for pinealoma. A 14-year-old boy was admitted to author's department on December 9, 1983, complaining of headache. He underwent a ventriculoperitoneal shunt on August 28, 1980 under the diagnosis of hydrocephalus caused by pinealoma. After the operation hydrocephalus improved. The patient had radiotherapy of 5090 rad. CT scan taken after the irradiation revealed reduction of the size of the tumor. On August 30, 1983, a ring calcification of epidural hematoma in the right parietal region was noticed on CT and plain skull X-rays. He was readmitted because of headache. There was no history of head injury. The calcified epidural hematoma was totally removed on December 12, 1983. The extirpated calcified epidural hematoma was 7.0 X 7.5 cm and 2.5 cm in thickness. Capsule formation was observed and ossification was also seen at dural side. No inflammatory finding was seen on histological examination. The postoperative course was uneventful. Etiology of calcified intracranial hematoma was discussed in relation to the present report, the relevant literature reviewed.

Adolescent↗