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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 19 recordsLinked to original sources
PubMed2005

Single burr hole surgery for the spheno-orbital fibrous dysplasia using intraoperative computed tomography.

Total removal of spheno-orbital fibrous dysplasia was achieved through intraoperative CT-assisted surgery via a burr hole. A 32-year-old man had persistent headache. Radiological studies demonstrated a small osteolytic lesion in the sphenoidal bone underneath the superior orbital fissure. Intraoperative serial CT scans showed the depth and width of the tumor within the complicated structure of the skull base. The lesion was successfully removed by CT-guided minimally invasive surgery.

Adult↗
PubMed2003

Frameless stereotactic radiosurgery with mobile CT, mask immobilization and micro-multileaf collimators.

We present frameless stereotactic radiosurgery using mobile CT, thermal plastic mask fixation, a vacuum-form body immobilizer and micro-multileaf collimators. A linear accelerator and a self-moving helical CT scanner gantry were installed in the same room. The isocenter of irradiation can be also aligned with the center of the CT gantry by rotating the couch. A thermal plastic mask and vacuum-form body immobilizer was used for registration and immobilization. The advantages of this system are as follows: 1) Accurate and painless frameless fractionated irradiation can be performed smoothly, as the patient's head is fixed without exchanging the couch from CT scanning to irradiation system. 2) This mask system can be applied to children, infants or adults with a previous craniotomy bone flap that must have a fixation pin placed into it. This system can be also used for fractionated radiotherapy without painful skull pin-fixed frame. 3) 1 mm micro-multileaf collimators enable irregular contour irradiation. 4) Image fusion (among CT, MRI, angiography, and PET) and 3D images can be used for irradiation planning. 5) This system can be used on any part of the body. 6) This system can be installed in any irradiation room without any extension or new construction.

Brain Neoplasms↗
PubMed2001

Ultrastructure of NADPH diaphorase-positive nerve fibers and their terminals in the rat cerebral arterial system.

To investigate how perivascular NO synthase (NOS)-containing nerves in the cerebral arterial system are involved in controlling the cerebral circulation, we observed the ultrastructure of NOS-containing nerve fibers and their terminals by means of nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH-d) histochemistry. We also observed the correlation between NADPH-d stained perivascular nerves and the perivascular sympathetic nerves, by means of double staining with NADPH-d histochemistry and tyrosine hydroxylase (TH) immunohistochemistry at the light microscopic level. NADPH-d-positive nerve fibers showed dense distribution mainly in the rostral portion of the circle of Willis and proximal portions of its main branches, where some of the NADPH-d-positive fibers coexisted with TH-positive fibers in a single nerve bundle. NADPH-d-positive nerve fibers were unmyelinated and had close contact with NADPH-d-negative myelinated and unmyelinated nerve fibers in a single nerve bundle, and NADPH-d-positive nerve terminals also existed closely with NADPH-d-negative nerve terminals. The number of NADPH-d-positive nerve terminals and their ratio to all other terminals were significantly higher in the rostral portion of the circle of Willis and the proximal portion of its branches, than the caudal portion of the circle of Willis and the distal portion of its branches. Nerve terminals were observed to locate within 250 nm from the basal lamina of arterial smooth muscle cells in the rostral portion of the circle of Willis and proximal portion of its branching arteries. The present observation confirmed that NOS-containing nerve fibers truly innervate the smooth muscle cells of the arterial wall in the circle of Willis and its main branches. Close contact between NADPH-d-positive and -negative nerve fibers and terminals in these arterial portions may indicate that NOS-containing perivascular nerves may work to modulate the rest of the other perivascular nervous system, such as the sympathetic nerves, to regulate the homeostasis of the arterial tonus.

Animals↗
PubMed2001

Retroperitoneal fibrosis and immune-complex glomerulonephritis.

A 63-year-old man with rapidly progressive glomerulonephritis of the immune-complex type showed typical findings of idiopathic retroperitoneal fibrosis involving the left ureter resulting in hydronephrosis. Treatment with steroid improved both conditions. Our case and previously reported cases showing the same association of conditions support the hypothesis that the association is not fortuitous but reflects a common immunological mechanism.

Disease Progression↗
PubMed2001

[Contrivance for frozen section diagnosis of early minute lung cancer during operation].

We reported the technique of pathological diagnosis for minute lung cancer lesion of early stage during operation. Target lesion for our technique may be less than 1 cm in size and not be detected by palpation. Our technique may superior to usual method of frozen section of tissue specimen without fixation. At first, resected lung specimen was fixed by injection of 20% formalin solution subsequent warming by microwave oven for 40 seconds. Almost all lesions may be detected in proper thickness of specimen. Specimen was washed out and steeped in the 20% of sucrose solution for 30 to 60 seconds in order to avoid crystallization of water that was contained within lung specimen. Then thin sliced section of specimen was made by Cryostat in usual method. The minute cancer lesion was able to detect more easy than usual method of making frozen section of specimen. Formalin fixed and sucrose steeped frozen section may be able to evaluate the surgical margin from cancer exactly than the section made by non-fixed specimen.

Frozen Sections↗
PubMed2000

Effect of an antioxidant, ebselen, on development of chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

BACKGROUND: Oxidation and/or free radical reactions after subarachnoid hemorrhage (SAH) may be involved in the development of chronic cerebral vasospasm. The inhibition of these reactions is thought to be one of the therapeutic strategies for prevention of cerebral vasospasm. We investigated the effect of Ebselen, a synthetic seleno-organic compound, which exhibits anti-oxidation by glutathione peroxidaselike activity to inhibit free radical reactions by lipid peroxidation on the development of chronic cerebral vasospasm in a primate model. METHODS: Seventeen monkeys were used. SAH was produced by introduction of a blood clot around the right middle cerebral artery and the right side of the circle of Willis in all animals. The monkeys were randomly divided into three groups according to Ebselen dosage: 1) no dosage or non-treated group; 2) high-dose Ebselen group; and 3) low-dose Ebselen group. The drug was administered at 10 mg/Kg in the high-dose group and 5 mg/Kg in the low-dose group twice a day in each group for 7 days after SAH. The vessel diameter was evaluated on angiograms before the induction of SAH and at Day 7 following SAH. RESULTS: In the untreated group, the angiograms showed significant (p < 0.05) reductions of the mean vessel caliber of the right internal carotid (ICA) (38 +/- 10% reduction) and the middle cerebral artery (MCA) (56 +/- 9.7%) compared with the baseline value before SAH. In the high-dose Ebselen-treated group, the mean percent reduction in vessel caliber of the right ICA (16 +/- 11%) and MCA (28 +/- 9.5%) on Day 7 angiograms were significantly (p < 0.05) lower than those in the nontreated group, whereas the mean percent reduction of these vessels in the low-dose Ebselen-treated group showed no significant difference compared with the untreated group. CONCLUSIONS: Chronic cerebral vasospasm was inhibited in the animals in which a relatively large amount of Ebselen was administered for 7 days after SAH. The results suggest that the oxidation or free radical reaction by lipid peroxidation after SAH might be involved in the pathogenesis of vasospasm, and that inhibition of these reactions by drugs, such as Ebselen, may have a promising effect for prevention of vasospasm.

Animals↗
PubMed2000

Relationship between EMG signals and force in human vastus lateralis muscle using multiple bipolar wire electrodes.

This paper describes the relationship between knee extension force and EMG signals detected by multiple bipolar wire electrodes inserted into the human vastus lateralis muscle under isometric conditions. Six healthy male volunteers participated in this study. Eight pairs of bipolar wire electrodes were inserted into the right vastus lateralis muscle and the EMG data were simultaneously detected and analyzed. The EMG raw data and individual force-IEMG relations were influenced by the location of the electrode inserted into the muscle. The force and IEMG relationship averaged across subjects detected from the eight electrodes, however, showed almost the same linear correlation in spite of different electrode locations. No linear correlation was observed between MdF and the knee extension force. This result suggests that, if all of the muscle fibers participate in the same action at the same time, the averaged normalized IEMG from any places using wire electrodes could reflect the total activities of that muscle even if the muscle is large.

Adult↗
PubMed2000

Computer-aided generation of stimulation data and model identification for functional electrical stimulation (FES) control of lower extremities.

Standard stimulation data for unassisted standing up of paraplegic patients was generated by dynamic optimization linked with model simulation, to overcome the difficulties in the present electromyogram (EMG)-based method. The generated stimulation data were roughly in agreement with the normal subjects' EMG. From these, it is suggested that the 'model-based' method is useful as an alternative of the 'EMG-based method'. The same technique can be applied to generation of patient-specific stimulation data once the musculoskeletal system of a patient is properly identified. The musculoskeletal system must be identified from data taken from simple and noninvasive experiments for the identification method to be practically acceptable. We developed a musculoskeletal model and systematic identification protocols for this purpose. They were validated for the vastus lateralis muscle at the knee joint. The identification was successful and the predicted joint angle trajectories closely matched the experimental data. This implies that the model-based generation of patient-specific stimulation data is possible.

Computer Simulation↗
PubMed2000

Localization of mRNAs for novel, atypical as well as conventional protein kinase C (PKC) isoforms in the brain of developing and mature rats.

Using in situ hybridization histochemistry, the localization of mRNAs for 10 isoforms of protein kinase C (PKC) in the rat brain was studied at embryonic and postnatal stages. In the embryonic brain, the gene expression was positive only for PKCepsilon, mu, lambda, and zeta with the former three more evident: The expression for PKCmu and lambda in the ventricular germinal zone and that for PKCepsilon, zeta, and lambda in the mantle zone. In the postnatal brain, the expression for PKCdelta, eta, and theta was detected differentially in a few circumscribed loci such as the thalamus, the habenula, the septum, and the cerebellar granule cells, whereas that for the other isoforms was seen widely in various loci of the gray matter with different intensity. The expression in the cerebellar external granule cell layer was positive only for PKCbeta (betaI and betaII), mu, and lambda with that for PKCbeta confined to its inner zone. There is a general tendency for all PKC isoforms that the expression levels reach at peaks in early postnatal brain and decreases more or less in adult specimens. This is the first report on the spatio-temporal heterogeneity in the gene expression for the whole members of PKC family in the brain throughout development, especially at embryonic days.

Aging↗
PubMed1999

Establishment of a simple and practical procedure applicable to therapeutic angiogenesis.

BACKGROUND: Therapeutic angiogenesis is thought to be beneficial for serious ischemic diseases. This investigation was designed to establish a simple and practical procedure applicable to therapeutic angiogenesis. METHODS AND RESULTS: When cultured skeletal muscle cells were electrically stimulated at a voltage that did not cause their contraction, vascular endothelial growth factor (VEGF) mRNA was augmented at an optimal-frequency stimulation. This increase of VEGF mRNA was derived primarily from transcriptional activation. Electrical stimulation increased the secretion of VEGF protein into the medium. This conditioned medium then augmented the growth of endothelial cells. The effect of electrical stimulation was further confirmed in a rat model of hindlimb ischemia. The tibialis anterior muscle in the ischemic limb was electrically stimulated. The frequency of stimulation was 50 Hz and strength was 0.1 V, which was far below the threshold for muscle contraction. After a 5-day stimulation, there was a significant increase in blood flow within the muscle. Immunohistochemical analysis revealed that VEGF protein was synthesized and capillary density was significantly increased in the stimulated muscle. Rats tolerated this procedure very well, and there was no muscle contraction, muscle injury, or restriction in movement. CONCLUSIONS: We propose this procedure as a simple and practical method of therapeutic angiogenesis.

Animals↗
PubMed1999

Localization of mRNA for Dri 42, subtype 2b of phosphatidic acid phosphatase, in the rat brain during development.

The expression of a gene termed Dri 42, a differentiation-related gene originally identified from intestine and a gene encoding phosphatidic acid phosphatase 2b isoform, was localized in developing and matured rat brains by in situ hybridization histochemical analysis. The gene expression was dominant in the ventricular germinal zone without significant expression in the intermediate, mantle and marginal zones throughout embryonic brain and spinal cord. The dominant expression in the ventricular germinal zone was maintained at P0 and P7, but it markedly decreased at later postnatal stages, while persistently high expression was detected in Bergmann glial cells of the cerebellar Purkinje cell layer throughout the postnatal development.

Animals↗
PubMed1999

Alterations of calcium/calmodulin-dependent protein kinase II activity in ischaemia-induced neuronal death and neuronal protection against ischaemia in the gerbil hippocampus.

To clarify the relation between neuronal protection against ischaemia and calcium/calmodulin-dependent protein kinase II (CaM kinase II) activity, we investigated temporal alterations of the kinase activity in the hippocampus after transient forebrain ischaemia under neuroprotective conditions, employing the gerbil bilateral carotid artery occlusion model. The hippocampal CA1 neuronal density at 2 hours after 5 minutes of forebrain ischaemia was 214.7 +/- 25.8/mm (mean +/- S.D.), and did not differ from the control significantly; however, it decreased to 11.7 +/- 4.2/mm at 7 days after the ischaemia. The neuronal density at 7 days after the ischaemia was 185.1 +/- 18.5 under the hypothermic conditions, 128.7 +/- 19.6 with the brief ischaemic pretreatment, 65.0 +/- 13.4 with administration of MK-801, and 20.5 +/- 4.2 with the repetitive hyperthermic pretreatment, respectively. The Ca2+/calmodulin-dependent activity of CaM kinase II in the hippocampal cytosolic fraction was decreased to 47.5% of the control value at 2 hours after the ischaemia, when CA1 neuronal death was not observed. In contrast, the activity was 98.8% of the control under the hypothermic conditions, 91.4% with the brief ischaemic pretreatment, 71.2% with administration of MK-801, and 47.9% with the repetitive hyperthermic pretreatment, respectively. These results indicated that the preservation of the Ca2+/calmodulin-dependent activity of cytosolic CaM kinase II after ischaemia parallelled the neuroprotective effect in the gerbil hippocampus. Thus, it is suggested that the preservation of the activity may be involved in the mechanism of neuronal protection against ischaemia.

Animals↗
PubMed1999

Tubal pregnancy in a unicornuate uterus with rudimentary horn: a case report.

OBJECTIVE: To report a case of tubal pregnancy in a unicornuate uterus with rudimentary horn on the side of the rudiment and its pathology. DESIGN: Case report. SETTING: University hospital. PATIENT: An 18-year-old woman, primigravida, with tubal pregnancy. INTERVENTION(S): Systemic administration of methotrexate, salpingectomy by laparotomy, and laparoscopic surgery for resection of rudimentary horn. MAIN OUTCOME MEASURE(S): Emergent laparotomy revealed that the intraperitoneal hemorrhage was caused by the rupture of the tubal pregnancy on the same side as the rudimentary horn of the unicornuate uterus. A corpus luteum was found at the ipsilateral ovary of the rudimentary horn. RESULT(S): Image diagnosis and pathological examination of the rudimentary horn revealed that this uterine malformation was a unicornuate uterus with a noncommunicated, noncavitary rudimentary horn, corresponding to class IIc of the American Fertility Society classification of müllerian anomalies. CONCLUSION(S): This is the first report of a tubal pregnancy on the side of the noncommunicating rudimentary horn with the ipsilateral ovary carrying a corpus luteum in a unicornuate uterus.

Abortifacient Agents, Nonsteroidal↗
PubMed1999

Reduction in subluxation and improved muscle function of the hemiplegic shoulder joint after therapeutic electrical stimulation.

Seventeen hemiplegic patients with chronic shoulder subluxation secondary to a cerebrovascular accident (CVA) were divided into three groups, two of which were subjected to 6 weeks of therapeutic electrical stimulation (TES) for 15 minutes twice a day, in order to assess the effectiveness of the treatment in reducing subluxation, and in improving shoulder abduction function. The third group was used as a control (C group). After 6 weeks of electrical stimulation of the supraspinatus (S group) and deltoid (D group), a significant (p<0.05) reduction in subluxation was observed in both groups when compared to the C group. The maximal force of shoulder abduction showed a tendency to increase in the S group (p<0.10). A significant increase in maximal force was also observed in the D group. In most of the TES-treated muscles, the interference pattern of EMG at maximum voluntary contraction increased. The amplitude of the EMG activity of the stimulated muscle also increased. Thus, we concluded that electrical stimulation therapy of the supraspinatus and the deltoid muscle is an effective treatment modality for shoulder subluxation and shoulder abduction function in hemiplegic patients.

Chronic Disease↗
PubMed1999

Hemodynamic and metabolic changes following cerebral revascularization in patients with cerebral occlusive diseases.

Changes in cerebral hemodynamics and metabolism following cerebral revascularization were evaluated using positron emission tomography (PET). Ten patients who had received nonsurgical treatment for 3-6 months for minor completed stroke underwent superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery. All patients showed no extensive infarction on MR, and responsible vascular lesions were detected in the anterior circulation. A PET study of cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate for oxygen (CMRO2), and cerebral metabolic rate for glucose (CMRGlu) measurements was performed before and 1.5 months after surgery using a steady state technique. Angiographically, anastomotic sites were patent in all patients. Seven patients showed neurological improvement after surgery and the others showed no improvement. The decreases in CBF, CMRO2 and CMRGlu recovered to some extent not only on the lesion side but also on the contralateral side after surgery. The increase in OEF values on the lesion side subsequently decreased after surgery. CMRO2 and CMRGlu showed parallel changes. It is concluded that the metabolic improvement afforded by the cerebral revascularization resulted in the neurological improvement, and that PET study is a powerful method for evaluating patients with cerebral occlusive diseases.

Aged↗