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Biomedical subjects

Michiyasu Suzuki

Publications and source records attributed to Michiyasu Suzuki.

At least 37 records · Page 2Linked to original sources
PubMed2004

A marked exophthalmos and corneal ulceration caused by delayed massive expansion of a subgaleal hematoma.

CASE REPORT: A 12-year-old girl had the hair on the right side of her head pulled during a quarrel, after which a subgaleal hematoma (SGH) developed over her right cranium. The subcutaneous swelling progressed to the forehead, and a marked exophthalmos then developed on the left side. The bilateral, liquefied SGH was removed surgically, and two drainage catheters connected to a vacuum-drain pump were introduced. After the surgery, the SGH disappeared. The liquefied hematoma was aspirated by puncturing the superolateral portion of the left orbit. Thereafter, the left exophthalmos rapidly disappeared. A chemical analysis of the SGH revealed that it contained extremely low levels of fibrinogen and platelets, and high levels of fibrinogen and fibrin degradation products, suggesting that secondary fibrinolysis had occurred in the subgaleal space. DISCUSSION AND CONCLUSION: Subgaleal hematomas are usually treated conservatively. However, closed observation is necessary, and if increased expansion is seen, aspiration with a closed drainage system should be considered.

Child↗
PubMed2004

Mutism after evacuation of acute subdural hematoma of the posterior fossa.

CASE REPORT: A 7-year-old boy was involved in a road traffic accident. A computed tomography scan revealed an acute subdural hematoma (ASDH) of the posterior fossa, traumatic subarachnoid hemorrhage, and distortion of the brain stem. Removal of the ASDH was completed 3.5 h after injury. After extubation, the patient rapidly recovered consciousness. He was able to follow commands, although he did not speak. He began to utter 14 days after the injury. His speech became normal 39 days after injury. A magnetic resonance imaging scan revealed a post-contusional change in the right cerebellum and an ischemic lesion in the pons. DISCUSSION: Immediate removal of the hematoma is the only therapy for patients with ASDH of the posterior fossa. Although any lesions of the dentate nucleus, red nucleus, thalamus, cerebral cortex, and pons, all of which are involved in this case, are able to cause mutism, his mutism was primarily caused by the severe ASDH of the posterior fossa. The transient nature of this syndrome suggests that the cause of the mutism is trauma-related edema and/or transient ischemia of these structures.

Accidents, Traffic↗
PubMed2004

Analysis of magnetic resonance imaging (MRI) morphometry and cerebral blood flow in patients with hypoxic-ischemic encephalopathy.

The aim of this study was to analyze magnetic resonance imaging (MRI) morphometry and cerebral blood flow (CBF) in patients with hypoxic-ischemic encephalopathy, and determine the viability of such measurements for predicting cerebral outcome. The subjects were 26 patients with histories of cardiopulmonary resuscitation who had subsequently developed encephalopathy. We examined the CBF using stable xenon-computed tomography (Xe-CT) and MR images in the subacute period (8-20 days). Three signal-change patterns in the basal ganglia emerged in the MRI study. The first pattern, isointense areas evident in both the T1-weighted image (T1WI) and the T2-weighted image (T2WI), was observed in four patients with favorable outcomes. The second pattern, iso- or hypointense areas evident in the T1WI and hyperintense areas evident in the T2WI, was observed in six patients with favorable outcomes and three patients with poor outcomes. The third pattern, hyperintense areas evident in both the T1WI and T2WI, was observed in 13 patients with poor outcomes. Hemispheric CBFs were 38.9+/-4.6 (mean (SD)) ml/100 g/min in patients with favorable outcomes and 25.3+/-4.3 ml/100 g/min in patients with poor outcomes (p < 0.01). The CBF increase after acetazolamide administration was 13.3+/-3.4 ml/100 g/min in patients with favorable outcomes and 6.8+/-5.6 ml/100 g/min in patients with poor outcomes ( p < 0.05). The presence of hyperintense lesions in the basal ganglia in T1WI, low hemispheric CBF ( < 30 ml/100 g/min), and low acetazolamide reactivity ( < 10 ml/100 g/min) are all factors associated with poor outcome in patients with hypoxic-ischemic encephalopathy.

Adolescent↗
PubMed2004

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion.

BACKGROUND: In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion. METHODS: After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm. RESULTS: Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits. CONCLUSION: PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.

Adult↗
PubMed2004

Anxiety before and after surgical repair in patients with asymptomatic unruptured intracranial aneurysm.

BACKGROUND: Ruptured intracranial aneurysm is a serious condition with high mortality and morbidity. Patients notified of the presence of the unruptured intracranial aneurysm may become anxious because of the fear of rupture. We prospectively investigated the anxiety of patients with unruptured intracranial aneurysm before and after surgery. METHODS: Thirty-seven patients with an asymptomatic unruptured intracranial aneurysm were enrolled, 13 men and 24 women aged 32 to 70 years (mean age, 57.2 years), who underwent surgical repair of the aneurysm. The anxiety of patients was assessed one month before and after surgery using the Japanese version of the State-Trait Anxiety Inventory. RESULTS: The trait anxiety scores, which refer to stable personality factors reflecting the general level of fearfulness, did not change significantly after surgery. In contrast, the state anxiety scores, which refer to transient anxiety that varies according to the situation, decreased significantly after surgery (p = 0.001, paired t test). Only the preoperative high state anxiety scores among the multiple variables were associated with the significant decrease in state anxiety after surgery (p = 0.0183, logistic regression analysis). CONCLUSIONS: The anxiety of patients with asymptomatic unruptured intracranial aneurysm significantly decreased after surgery. Anxiety of patients with asymptomatic unruptured intracranial aneurysm may deserve attention in deciding whether to treat the aneurysm.

Adult↗
PubMed2004

Increased matrix metalloproteinase-9 in blood in association with activation of interleukin-6 after traumatic brain injury: influence of hypothermic therapy.

Recent experimental data have shown that levels of matrix metalloproteinase-9 (MMP-9) increase after traumatic brain injury (TBI), degrading components of the basal lamina disrupting the blood-brain barrier. However, the post-traumatic secretion patterns of MMP-9 in humans are unknown. We measured the concentration of MMP-9 in plasma after TBI at the same time as the concentration of interleukin-6 (IL-6) in serum. Levels of MMP-9 and IL-6 in systemic arterial and jugular venous blood from seven patients with TBI were measured on days 0 and 1 post-injury. All patients underwent hypothermia at 32-35 degrees C as soon as possible after admission. Before induction of hypothermia, levels of MMP-9 in arterial and internal jugular venous blood exceeded the normal range. Higher MMP-9 levels were detected in internal jugular venous blood than in arterial blood. After hypothermia had been induced, MMP-9 levels in arterial blood and internal jugular venous blood decreased significantly, to within the normal range. In addition to these changes, a significant correlation was seen between levels of MMP-9 and IL-6 in internal jugular venous blood during the investigation period. These results indicate that MMP-9 is elevated in patients with acute TBI, and may play an important role in traumatic brain damage. The elevation of MMP-9 is associated with inflammatory events following TBI. Hypothermic intervention may suppress the elevation of MMP-9 with suppression of the inflammatory response, affording neuroprotection in TBI.

Adolescent↗
PubMed2004

Vaccine therapy for murine glioma using tumor cells genetically modified to express B7.1.

OBJECTIVE: In a syngeneic mouse brain tumor model, we tested the hypothesis that vaccination with tumor cells genetically modified to express B7.1 molecules induces tumor-specific T cells and immunological antitumor effects. METHODS: Malignant glioma cells (RSV-MG) derived from a C3H/He mouse induced by Schmidt-Ruppin Rous sarcoma virus (RSV) were infected with an adenovirus encoding the B7.1 gene (AdB7). To investigate the effects of B7.1 expression on the tumorigenicity of RSV-MG cells, infected cells were implanted subcutaneously into C3H/He mice. The C3H/He mice were vaccinated with AdB7 transfectants injected subcutaneously and 2 weeks later were challenged intracerebrally with wild-type RSV-MG cells to determine whether or not the expression of B7.1 would enhance the immunogenicity of RSV-MG cells. RESULTS: Immunocytochemistry confirmed the expression of B7.1 and major histocompatibility complex Class I antigen on the infected cells. The growth of subcutaneous tumors was markedly retarded in the AdB7 group, whereas tumors had formed and progressively increased in size in the other control groups. In the vaccine experiments, the mice immunized with AdB7 transfectants survived longer than did the mice of the other groups, and a significant difference in survival times was noted. Immunocytochemistry revealed that brain tumors in mice previously vaccinated with AdB7 infectants had been infiltrated by a larger number of CD3(+) lymphocytes and that these CD3(+) lymphocytes contained not only CD4(+) and CD8(+) T cells but also CD25(+)-activated T cells. In addition, a cytotoxicity assay confirmed that vaccination with the AdB7 transfectants induced tumor-specific cytotoxicity. CONCLUSION: These results demonstrate the therapeutic potential of vaccination with tumor cells expressing B7.1 for the treatment of malignant glioma.

Adenoviridae↗
PubMed2004

[A case of Rathke's cleft cyst in association with bilateral unruptured aneurysms of internal carotid artery].

Recent progress in diagnostic imaging techniques, such as MRI and CT, has shown that Rathke's cleft cyst is more common than once thought. However, few cases have been reported in which a cerebral arterial aneurysm was merged with a symptomatic Rathke's cleft cyst. We present a case of bilateral internal carotid aneurysms associated with a symptomatic giant Rathke's cleft cyst. A 66-year-old-woman with a visual disturbance was admitted to our hospital. CT and MRI showed a large mass in the frontal base to the suprasellar region. The mass showed isosignal intensity in T1-weighted images (WI), a ringed enhancement with Gd-DTPA, and hyperintensity in T2WI. An angiography showed bilateral A1 elevation but no tumor stain. In addition, unruptured aneurysms appeared in the inside back C2 portion of the bilateral internal carotid arteries. For these lesions, a bifrontal craniotomy was performed. In a single operative approach, the mass lesion was removed and the aneurysms were successfully clipped. The aneurysms adhered strongly to the wall of the mass. The histological diagnosis of the mass was Rathke's cleft cyst. A precise pre-operative understanding of the anatomical structure and a careful operative procedure are important for the treatment of these complex lesions.

Aged↗
PubMed2004

[A case of intractable epilepsy presenting epileptic spasm treated with callosotomy in childhood].

We present a case of intractable epilepsy presenting epileptic spasm successfully treated with anterior callosotomy in childhood. A 12-year-old boy had seizures frequently since the age of 11 months which were diagnosed as an infantile spasm. He underwent various treatments including ACTH therapy, but the seizures were intractable. Characteristics of his seizures were an abrupt axial movement leading to sustained posturing, most often truncal, and neck flexion with pronounced arm extension and abduction. He lost consciousness transiently and these seizures frequently occurred in clusters and the duration of seizure was 1 to 3 seconds. Neurologically he had no deficit, but his intelligence was below the standard level. Magnetic resonance image (MRI) showed no abnormalities in the brain. Electroencephalogram (EEG) demonstrated secondary bilateral synchrony (SBS) with left frontal dominance in amplitude. Subdural strip electrodes were implanted bilaterally over the frontal lobes to detect an epileptogenic region. However intracranial ictal-EEG demonstrated an abrupt bilateral desynchronization for 1-3 seconds. As the epileptogenic zone was not clearly identified and an abrupt bilateral desynchronization was identified, anterior callosotomy was performed. Since surgery, he has remained seizure-free for two years while taking anticonvulsants and the SBS has disappeared. This case may indicate that the corpus callosum influences the occurrence of epileptic spasm and SBS on EEG.

Child↗
PubMed2003

Brain and systemic temperature in patients with severe subarachnoid hemorrhage.

BACKGROUND: The significance of brain temperature (BT) in patients with severe brain damage remains unclear. This study investigated the relationships between BT, systemic temperature (ST), and clinical outcome in patients with severe subarachnoid hemorrhage. METHODS: Thirty-one comatose patients with severe subarachnoid hemorrhage underwent ventricular drainage immediately after admission. The ventricular catheter also allowed monitoring of BT. ST was continuously measured using a bladder catheter with thermistor probe. RESULTS: BT at the start of the monitoring was lower than ST in four patients, and all died of brain swelling. BT was higher than ST at first but later fell below ST ("temperature reversal") in 12 patients, who all died of acute brain swelling. BT was higher than ST throughout the monitoring in 15 patients. Five of these patients died of causes other than brain swelling such as rerupture of the cerebral aneurysm, multiple organ failure, or respiratory failure. The other 10 patients survived with various degrees of disability. CONCLUSIONS: Observation of BT and ST can predict the outcome of severe subarachnoid hemorrhage.

Adult↗
PubMed2003

Brain temperature and cerebral blood flow imaging in patients with severe subarachnoid hemorrhage: report of two cases.

BACKGROUND: Temperature reversal, which is defined as observation of higher brain temperature than systemic temperature followed by lower brain temperature than systemic temperature, implies a poor prognosis in patients with severe subarachnoid hemorrhage (SAH). Serial regional cerebral blood flow (CBF) imaging using single-photon emission tomography (SPECT) was performed in 2 patients with severe SAH who showed temperature reversal. CASE DESCRIPTION: 54-year-old woman and a 55-year-old man with severe SAH underwent ventricular drainage using a catheter that allowed monitoring of the brain temperature. SPECT imaging in these two patients showed that CBF was preserved before the occurrence of the temperature reversal and was exhausted afterwards. These patients died within 2 to 3 days. CONCLUSIONS: Temperature reversal may indicate the exact time when absence of brain perfusion occurs, causing irreversible brain damage.

Body Temperature↗
PubMed2003

Improvement in cognitive function after radical excision of an anterior skull base meningioma--a report of 2 cases.

It has been well documented that memory difficulties in patients with anterior skull base meningioma may improve after tumour resection. However, there have been few reports on studies where precise testing of cognitive function has been conducted before and after surgery. Here we report 2 cases of anterior skull base meningioma where 2 tests of cognitive function, the Wechsler adult intelligence scale-revised (WAIS-R) and the Wechsler memory scale-revised (WMS-R), were performed by the patient before and after surgical treatment. After the operation there was a dramatic increase in the performance IQ as measured by the WAIS-R. In addition, the scores for both the "Attention/Concentration" and the "Delayed Recall" subsets of the WMS-R scale improved. There were differences between the 2 patients in the length of time required for functional recovery and this was thought to be due to the tumour size and the age of the patient. The use of these scales would enable physicians who are treating patients with anterior skull base meningioma to assess the recovery time that is likely to be needed before full return of cognitive function after surgery.

Adult↗
PubMed2003

Mild hypothermia inhibits exogenous glutamate-induced increases in nitric oxide synthesis.

The purpose of this study was to investigate changes in nitric oxide (NO) synthesis induced by exogenous glutamate perfusion into the cerebral cortex, and the effects of mild hypothermia on this glutamate-induced NO synthesis. Glutamate-induced cortical lesions were produced by perfusion of 0.5 M glutamate solution via a microdialysis probe, and the extracellular concentrations of NO end-products (nitrite and nitrate) were measured by microdialysis in normothermic (37 degrees C) and hypothermic (32 degrees C) rats. The levels of NO end-products in the normothermia group were elevated markedly by glutamate perfusion, and this change was completely attenuated by the induction of hypothermia. The glutamate-induced increases were also attenuated markedly by both Nomega-nitro-L-arginine methyl ester (L-NAME) and 7-nitroindazole (7-NI). These results suggest that the perfusion of exogenous glutamate into the cortex induces NO synthesis, that is derived primarily from the activity of neuronal NO synthase. These results also demonstrate that hypothermia prevents this glutamate-induced increase in NO, suggesting that the protection afforded by the hypothermic condition is most likely linked to its inhibition of the glutamate-induced NO synthesis.

Animals↗
PubMed2003

Aspirin inhibits Chlamydia pneumoniae-induced NF-kappa B activation, cyclo-oxygenase-2 expression and prostaglandin E2 synthesis and attenuates chlamydial growth.

Infection with Chlamydia pneumoniae has been implicated as a potential risk factor for atherosclerosis. This study was designed to investigate the mechanisms of the anti-chlamydial activity of aspirin. A reporter gene assay for NF-kappa B activity, immunoblot analysis for cyclo-oxygenase (COX)-2 and radioimmunoassay for prostaglandin E(2) (PGE(2)) were performed. Following infection of HEp-2 cells with C. pneumoniae, NF-kappa B was activated, COX-2 was induced and PGE(2) was elevated. Aspirin inhibited NF-kappa B activation at a concentration of 0.1 mM, partially inhibited COX-2 induction and blocked PGE(2) synthesis completely. In addition, high doses of aspirin (1 and 2 mM) inhibited chlamydial growth in HEp-2 cells, decreasing the number and size of inclusion bodies; this effect could be overcome by adding tryptophan to the culture. Indomethacin also blocked the synthesis of PGE(2), but had no effect on COX-2 expression or chlamydial growth. These results indicate that aspirin not only has an anti-inflammatory activity through prevention of NF-kappa B activation but also has anti-chlamydial activity at high doses, possibly through depletion of tryptophan in HEp-2 cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Ictal onset and spreading of seizures of parietal lobe origin.

The characteristics of seizures associated with parietal lobe epilepsy were investigated in six consecutive patients with medically intractable epilepsy due to parietal lobe lesions. Intracranial electrode recordings were retrospectively reviewed to investigate the seizure onset symptoms and spreading patterns associated with the disorder. All six patients underwent implantation of subdural or depth electrodes and subsequent video/electroencephalography monitoring. Common symptoms included motionless stare, contralateral eye deviation, and head turn. Tonic posturing, contralateral sensory disturbance, and motor weakness were also seen. Asymmetrical generalized tonic and clonic seizures were seen in all six patients. All seizure activities began in the parietal lobe harboring the lesions, and then spread immediately to the adjacent lobes in most seizures, where the clinical symptoms were produced. The parietal lobe is a pure generator of seizures, whereas most clinical symptoms originate from adjacent lobes following seizure onset. No apparent specific symptoms other than sensory disturbance arising from the parietal lobe proper were recognized. Regardless of clinical symptoms, the seizure onset occurred in the parietal lobe harboring the lesion.

Adult↗
PubMed2003

[Surgical reconstruction of the common carotid artery by an ePTFE graft for invasive thyroid cancer: a case report].

Surgical reconstruction of the carotid artery using a synthetic graft is rarely performed. A 71-year-old woman developed hoarseness and was diagnosed as having thyroid cancer. Computed tomography (CT) and angiography revealed an irregular thyroid tumor invading the left common carotid artery, and encasement of the artery by the tumor. Left common carotid angiography showed an irregularity of the common carotid artery wall and a dense tumor stain fed by the superior thyroid artery. Dissection of the thyroid cancer from the common carotid artery was judged to be impossible during surgery, so resection of the whole tumor together with the common carotid artery was carried out. The left common carotid artery was reconstructed using an expanded polytetrafluoroethylene (ePTFE) graft. No cerebral ischemia was evident after surgery. Postoperative CT and magnetic resonance angiography demonstrated patency of the carotid artery, and no tumor recurrence was confirmed at a 27-month follow up. The ePTFE graft appears to be a suitable synthetic graft for reconstruction of the carotid artery.

Aged↗
PubMed2002

Sphingosylphosphorylcholine is a novel messenger for Rho-kinase-mediated Ca2+ sensitization in the bovine cerebral artery: unimportant role for protein kinase C.

Although recent investigations have suggested that a Rho-kinase-mediated Ca2+ sensitization of vascular smooth muscle contraction plays a critical role in the pathogenesis of cerebral and coronary vasospasm, the upstream of this signal transduction has not been elucidated. In addition, the involvement of protein kinase C (PKC) may also be related to cerebral vasospasm. We recently reported that sphingosylphosphorylcholine (SPC), a sphingolipid, induces Rho-kinase-mediated Ca2+ sensitization in pig coronary arteries. The purpose of this present study was to examine the possible mediation of SPC in Ca2+ sensitization of the bovine middle cerebral artery (MCA) and the relation to signal transduction pathways mediated by Rho-kinase and PKC. In intact MCA, SPC induced a concentration-dependent (EC50=3.0 micromol/L) contraction, without [Ca2+]i elevation. In membrane-permeabilized MCA, SPC induced Ca2+ sensitization even in the absence of added GTP, which is required for activation of G-proteins coupled to membrane receptors. The SPC-induced Ca2+ sensitization was blocked by a Rho-kinase inhibitor (Y-27632) and a dominant-negative Rho-kinase, but not by a pseudosubstrate peptide for conventional PKC, which abolished the Ca2+-independent contraction induced by phorbol ester. In contrast, phorbol ester-induced Ca2+ sensitization was resistant to a Rho-kinase inhibitor and a dominant-negative Rho-kinase. In primary cultured vascular smooth muscle cells, SPC induced the translocation of cytosolic Rho-kinase to the cell membrane. We propose that SPC is a novel messenger for Rho-kinase-mediated Ca2+ sensitization of cerebral arterial smooth muscle and, therefore, may play a pivotal role in the pathogenesis of abnormal contraction of the cerebral artery such as vasospasm. The SPC/Rho-kinase pathway functions independently of the PKC pathway.

Animals↗