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Biomedical subjects

K Satomi

Publications and source records attributed to K Satomi.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Anesthetic management of pheochromocytoma by continuous intravenous injection of prostaglandin E1].

We had five cases of surgical removal of pheochromocytoma by continuous intravenous injection of prostaglandin E1. During anesthesia, we used Swan-Ganz catheter for circulatory monitoring and measured plasma catecholamines. When PGE1 dose was increased from 0.05 to 0.1 and 0.15 microgram.kg-1.min-1, total systemic vascular resistance and mean arterial pressure were decreased but heart rate and cardiac output were not significantly altered from the preanesthetic values. Plasma catecholamines were also similar to the preanesthetic values. Therefore, the results suggest that the mechanism of suppression of hypertension by PGE1 is by affecting vascular beds directly rather than by diminishing catecholamine excretion from sympathetic nerve and adrenal medulla. During manipulation of pheochromocytoma, mean arterial blood pressure increased extremely. Although PGE1 was injected at a rate of 0.3 to 0.5 microgram.kg-1.min-1 in some cases, we could not suppress the elevation of blood pressure. PGE1 alone could not normalize blood pressure and heart rate, and other cardiovascular agents were necessary.

Adolescent↗
PubMed1990

Experimental studies on spinal cord function using evoked action potentials.

Experiments were carried out on cats to determine the use of conductive evoked spinal cord action potentials in diagnosing motor function of the spinal cord. Direct stimulation from the dura produced three negative wave potentials, N1, N2 and N3. The intraspinal pathway of N2 and N3 was the dorsal column. The pathways of N1, determined by dorsal and ventral epidural recording, were the dorsilateral funicle and the extrapyramidal tracts. A collision experiment between potential N1 and pyramidal tract action potential did not reflect the function of the tract as the amplitude of the action potential was too small. Nevertheless, it is considered that conductive evoked spinal cord action potentials could become a valuable method of assessing spinal cord function as they reflect the function of the extrapyramidal tracts, as well as of the dorsilateral funicle and the dorsal column.

Action Potentials↗
PubMed1990

Initial interface between submerged hydroxyapatite-coated titanium alloy implant and mandibular bone after nontapping and tapping insertions in monkeys.

To clarify whether direct bone interface of submerged plasma-sprayed hydroxyapatite-coated implants could be achieved by nontapping insertion, histologic and histometric studies were made on the structure of the interface between the implant and the mandible in two monkeys. All hydroxyapatite-coated implants, whether by nontapping or tapping insertions, were healed with direct bone apposition. No histologic and histometric difference of interface structure was observed between nontapping and tapping insertions.

Alloys↗
PubMed1990

[Capsular pseudobulbar mutism in a patient of lacunar state].

A patient of mutism with pseudobulbar palsy and frontal lobe syndrome resulting from lacunar state was reported. The patient, a 64-year-old man, was admitted to Gifu University Hospital because of a decrease in spontaneous activity, lack of volition and anorexia. The CT scan, performed on July 29, 1987, demonstrated lacune in the right internal capsule (IC), periventricular lucency especially around the anterior horn of lateral ventricles, and ventricular dilatation. He was transferred to a medical ward because of repeated aspiration pneumonia. Neurological examination revealed mutism, pseudobulbar palsy, and frontal lobe signs. The CT scan, performed on March 30 1988, demonstrated the newly developed lacune in the left IC. The MRI also showed two coinciding lacunes, one in the genu of the right IC and the other in the anterior limb of the left IC. The SPECT with 123I iodoamphetamine showed decreased blood supply predominantly to the frontal lobes. A mechanism by which the mutism occurs is discussed from two points of view, pseudobulbar palsy and frontal lobe syndrome. He developed initially frontal lobe syndrome in which paucity of spontaneous speech was noted. The CT scan at that time demonstrated lacune in the right IC. About eight months later when he became mute, the CT scan showed lacunes in bilateral ICs without any other low density areas in frontal language areas such as Broca's area, subcortical area and supplementary motor area. As the MRI showed that the right lacune was in the genu but the left lacune was in the anterior limb of IC, the left cortico-bulbar tract was thought to be not directly involved. The SPECT showed decreased blood supply predominantly to the frontal lobes. Although dysphagia improved, mutism did not improve at all. Therefore it is postulated that both pseudobulbar palsy and frontal lobe dysfunction might play a role in producing the mutism of this patient.

Akinetic Mutism↗
PubMed1989

["My hand" sign associated with tactile extinction in two patients with callosal lesion].

Two patients with "my hand" sign in association with tactile extinction from callosal lesion, one due to left anterior cerebral artery occlusion, the other due to right anterior cerebral artery aneurysm rupture, were reported. The examination of "my hand" sign was performed with the methods proposed by Brion et al. Our patients correctly responded when they grasped their own or the examiner's thumb with their left hand. But they replied "my finger"when they grasped not only their own but also the examiner's thumb with their right hand. Left tactile extinction was observed after a routine extinction test in one patient, and it was observed in the other after the following method: both patient's index fingers were disposed in his midline position. In these methods of extinction test, they made errors in saying "right" when both fingers were touched simultaneously. However, they said "both" when their right index finger alone was touched (synchiria) during an extinction test using the following method: both index fingers of patients were approached by examiner to touch each other or for one of them to touch the examiner's finger. When they were asked whose finger they touched in this method (whose finger test), they made the same errors as seen in "my hand" sign test. These test results suggest that there is a common underlying mechanism in the "my hand" sign and extinction, because the sense of double stimulations felt when only one stimulation is given (synchiria), is a possible explanation for the "my hand" sign and the pathogenesis of synchiria appears to be related to extinction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Bone-implant interface structures after nontapping and tapping insertion of screw-type titanium alloy endosseous implants.

To compare different surgical insertion procedures, histologic and histometric studies were made on the structure of the interface between jaw bone and implants in two monkeys. Two materials were tested; TiO2 coated and noncoated, screw-type titanium alloy endosseous implants. All implants by tapping insertion were healed with direct bone apposition whereas implants by nontapping insertion revealed some degrees of fibrous connective tissue intervention between bone and implant. No difference was found between TiO2 coated and non-coated materials.

Alloys↗
PubMed1988

Level diagnosis of cervical myelopathy using evoked spinal cord potentials.

The ESCPs (evoked spinal cord potentials) resulting from both median nerve and spinal cord stimulation were recorded from the interlaminar yellow ligaments posteriorly or intervertebral discs anteriorly on patients with cervical myelopathy in order to determine the most significant lesion in the spinal cord electrophysiologically. The normal median-nerve-evoked spinal cord potential (MN-ESCP) consisted of P1N1 and N2(P2) deflections, while normal spinal cord-ascending evoked spinal cord potential (SC-AESCP) consisted of N1 and N2 deflections. The abnormal ESCPs obtained from 65 patients were classified into three grades. The spinal level recording the highest grade of ESCP, which was mostly positive wave, generally corresponded to the level that was clearly diagnosed as the main lesion by neurologic and radiologic examinations, such as a case of single level disc hernia. With these techniques, the level diagnostic rates of primary lesions were 94.7% in posterior recordings and 74.1% in anterior recordings.

Adult↗
PubMed1988

Tissue response to implanted ceramic-coated titanium alloys in rats.

In order to assess the tissue compatibility of the hybrid materials for the dental implant (hydroxyapatite, titanium oxide and titanium nitride coated titanium alloys), tissue response to these materials implanted in the rat subcutaneous tissue was histologically examined. Initial inflammatory response was less evident in titanium oxide coated and non-coated titanium alloys. All materials were encapsulated by thin fibrous connective tissues. The membrane thickness of hydroxyapatite coated titanium alloy was significantly higher than that of titanium nitride coated one. These results suggest that all materials possess favourable tissue compatibility and may encourage clinical use as the dental implant.

Alloys↗
PubMed1986

Initial bone-implant interfaces of submergible and supramergible endosseous single-crystal sapphire implants.

Three types of bone-single-crystal sapphire implant interfaces were histologically determined in submergible and supramergible implant: direct bone apposition (type I), thin connective tissue with poor collagen fibers (type II), and dense fibrous connective tissue (type III). Type I interface was predominant and type III interface was sparsely seen in submergible implants. In contrast to these findings, type III interfaces frequently appeared in supramergible implants, primarily at the apical region. These differences were considered to occur by the biomechanical variable of postoperative healing.

Aluminum↗
PubMed1985

Comparison of evoked spinal potentials by stimulation of the sciatic nerve and the spinal cord.

Spinal cord monitoring during surgery using evoked spinal potentials (ESP) is now popular. In cats, ESPs due to both sciatic nerve (SN-ESP) and spinal cord stimulation (SC-AESP and SC-DESP) were recorded from the epidural space. Both SN-ESP and SC-AESP were compared by parameter studies. Stimulus frequencies up to 100 Hz did not significantly alter the SC-AESP, whereas the later components of the SN-ESP decreased greatly in amplitude. The SN-ESP was more sensitive to asphyxia than the SC-AESP. Augmentation of the ESP occurred approximately 5 minutes after the asphyxia was introduced, which was interpreted as an impending sign of anoxia of the spinal cord. The SN-ESP had more potentials arising from synaptic and postsynaptic activities, while the SC-AESP was mainly derived from the spinal tracts. To monitor the function of the spinal cord, both methods should be used.

Animals↗
PubMed1983

Expansive open-door laminoplasty for cervical spinal stenotic myelopathy.

Although the operative results have been improving since the air drill was introduced for cervical laminectomy instead of an ordinary rongeur, post-laminectomy complications, such as postoperative fragility of the cervical spine to acute neck trauma, posterior spur formation at the vertebral body, and malalignment of the lateral curvature have still remained as unsolved problems. In order to avoid these disadvantages, a new surgical technique called "expansive open-door laminoplasty" was devised by the author in 1977, which is relatively easier, safer, and better than the ordinary laminectomy from the standpoint of structural mechanics of the cervical spine. The operative procedure is described in detail. Operative results in the patients with cervical OPLL, spondylosis, and canal stenosis were satisfactory, and optimal widening of the AP diameter of the spinal canal is considered to be over 4 mm. From this procedure a bilateral, open-door laminoplasty has been devised for extensive exploration at the intradural space.

Animals↗