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Biomedical subjects

Kazuhiro Hongo

Publications and source records attributed to Kazuhiro Hongo.

At least 19 recordsLinked to original sources
PubMed2006

Parkinsonism and midbrain dysfunction after shunt placement for obstructive hydrocephalus.

We report a patient in whom placement of a ventriculoperitoneal shunt for obstructive hydrocephalus secondary to non-neoplastic aqueductal stenosis was complicated by progressive parkinsonism and midbrain dysfunction. These sequelae were refractory to treatment, including shunt revision and levodopa therapy. These findings contradict the opinion from the literature that this type of parkinsonism is a reversible condition and levodopa therapy is effective for managing the symptoms. We discuss the pathophysiological mechanism of this complication.

Humans↗
PubMed2006

Continuous suction method in superficial temporal artery-middle cerebral artery anastomosis surgery. Technical note.

A new method was developed to maintain a bloodless microscopic operative field for superficial temporal artery-middle cerebral artery (MCA) anastomosis surgery. A silicone suction tube with multiple holes is placed circumferentially under the reflected dural flaps around the craniotomy. Blood and irrigated saline are continuously aspirated by the tube. Use of this method in nine patients significantly reduced the mean MCA trapping time (24.0 +/- 2.8 min) compared with nine patients treated using the conventional method (30.1 +/- 4.6 min). MCA trapping time is shortened because the surgery is not interrupted for manual suctioning of bloody cerebrospinal fluid.

Adult↗
PubMed2006

Middle cerebral artery occlusion associated with acute myocardial infarction in the perioperative period--case report.

A 68-year-old woman with no history of cardiac events suffered acute myocardial infarction after surgery for middle cerebral artery (MCA) occlusion manifesting as transient left motor weakness. Diffusion-weighted magnetic resonance imaging revealed multiple infarctions in the right cerebral hemisphere. Magnetic resonance angiography and cerebral angiography demonstrated an occlusion at the horizontal segment of the right MCA and no collateral circulation. Cerebral blood flow study 6 weeks after the initial presentation indicated decreased blood flow in the right cerebral hemisphere. Superficial temporal artery-MCA anastomosis was conducted to prevent recurrent cerebral infarction. Two hours after surgery, her systolic blood pressure fell to 60 mmHg and her consciousness worsened. Emergency coronary angiography indicated occlusion of the right coronary artery. Percutaneous coronary intervention was successfully performed and the subsequent course was uneventful. Preoperative evaluation of the coronary artery may be necessary before surgery for cerebral ischemic disease in both the intracranial and extracranial arteries.

Aged↗
PubMed2006

Transient cerebellar mutism caused by bilateral damage to the dentate nuclei after the second posterior fossa surgery. Case report.

The authors report on the case of a 6-year-old boy who underwent resection of a midline cerebellar tumor. The boy was able to speak fluently after the operation. Magnetic resonance (MR) imaging showed that the right dentate nucleus had been partially removed along with the tumor, but that the left dentate nucleus remained with the residual tumor. A second operation was performed to remove the residue, after which the child suffered mutism. Three weeks post-surgery, he could only communicate through gestures. He started speaking I week later and regained normal speech 2 months after the operation. Final MR imaging revealed gross-total removal of the tumor and dentate nucleus on the injured left side. The cerebellar mutism was considered to have been caused by bilateral damage to the dentate nuclei and not by unilateral damage.

Cerebellar Neoplasms↗
PubMed2006

[Intratumoral hemorrhage in choriocarcinoma during neuroendoscopic third ventriculostomy: case report].

The authors report a case of intratumoral hemorrhage in a pineal region choriocarcinoma during neuroendoscopic third ventriculostomy. A 12-year-old boy who presented with headache and vomiting had precocious puberty. Neuroimagings revealed a pineal region tumor with obstructive hydrocephalus and his serum HCG level was 4,280 mIU/ml. He was diagnosed as having choriocarcinoma and underwent neuroendoscopic third ventriculostomy for obstructive hydrocephalus. There were many tumor vessels observed on the tumor surface, some of which bled subcapsularly. Postoperative CT scan showed the tumor increased in size with the intratumoral hemorrhage. After irradiation and chemotherapy, the tumor disappeared with normalization of serum HCG level. His symptoms improved and no additional neurological deficit was observed in his clinical course. We might infer from this case that the intratumoral hemorrhage was induced by the intracranial pressure change during neuroendoscopic surgery. Perioperative management is very important for avoiding fetal intratumoral hemorrhage.

Brain Neoplasms↗
PubMed2005

Intraventricular administration of hepatocyte growth factor treats mouse communicating hydrocephalus induced by transforming growth factor beta1.

Communicating hydrocephalus may occur spontaneously in elderly patients or occur as a complication of meningitis or intracranial hemorrhage, typically as a result of fibrosis along the route of cerebrospinal fluid (CSF) flow. Hepatocyte growth factor (HGF) has anti-fibrotic properties and is a promising candidate for the treatment of various fibrotic diseases. Thus, the goal of this study was to examine the effect of exogenous HGF (30 microg of human recombinant (hr) HGF intraventricularly for 7 or 14 days) in a model of hr transforming growth factor beta1-induced communicating hydrocephalus in C57BL/6 mice. HGF treatment resulted in a reduction of ventriculomegaly, as demonstrated by magnetic resonance imaging, and improved spatial memory. Further, ink passage test demonstrated improvement of normalized CSF in flow in mice receiving HGF treatment as opposed to delayed CSF flow in the hydrocephalic mice at baseline. Finally, histological examination in hydrocephalic mice undergoing HGF treatment revealed reduction of collagen fibers in the meninges and normalization of their structures. These results indicate that exogenous HGF may be of utility in the treatment of hydrocephalus in humans.

Animals↗
PubMed2005

Thalamic stimulation for disabling tremor in a patient with spinocerebellar degeneration.

Thalamic stimulation alleviated coarse action tremor in a patient with spinocerebellar degeneration (SCD) and led to substantial improvement in daily functioning, though disability from ataxia remained. Intraoperative microrecording revealed a significant correlation between neuronal activity of the ventral intermediate nucleus (Vim) and tremor electromyograms. The tremor-correlated activities of Vim neurons and abolition of the tremor by Vim stimulation suggest that Vim may be related to the generation of action tremor in SCD. Thalamic stimulation can be a useful treatment option for SCD patients with disabling tremor.

Aged↗
PubMed2005

A container for transporting small laboratory animals for magnetic resonance imaging.

We have constructed a simple container, consisting of a propylene tube, a High-Efficiency Particulate Aerosol (HEPA) filter and a rubber glove, for transporting small animals to magnetic resonance imaging (MRI) facilities that are located outside a pathogen-free environment. Results of pathogens analysis indicate that the container is able to prevent infection by several microorganisms. The quality of the MR images of mice and rats transported in, and imaged while in the container was satisfactory. This container can be useful for examinations that required the use of instruments located outside clean animal units, ensuring safety for both humans and animals.

Aerosols↗
PubMed2005

Postoperative vasospasm of unruptured paraclinoid carotid aneurysms: analysis of 30 cases.

This study was conducted to determine the incidence, severity, and causes of delayed vasospasm after clipping of unruptured paraclinoid aneurysms of the internal carotid artery (ICA). A retrospective analysis was made of 30 patients, who underwent clipping of unruptured paraclinoid aneurysms in our institution between 1991 and 1998. We compared angiograms before and after operation and classified them into two groups: vasospasm group and non-vasospasm group. Eleven variables were assessed as to their relationship to delayed vasospasm. There were 9 patients (30%) in the vasospasm group, of which 3 patients (10%) were clinically symptomatic. For all symptomatic patients, aggressive treatment, including triple-H therapy, was conducted with good outcome. The number of clips used (p<0.04) and temporary occlusion of the ICA (p<0.005) were statistically significant factors associated with the incidence of vasospasm. It is suggested that mechanical stimulation to the vascular wall of the ICA is responsible for causing spasm in addition to intraoperative bleeding around the dural ring.

Adult↗
PubMed2005

A saccular-like dissecting aneurysm of the anterior cerebral artery that developed 2 years after an ischemic event.

BACKGROUND: A rare case of a growing dissecting aneurysm, which was located at the horizontal (A1) segment of the anterior cerebral artery (ACA), is reported. CASE DESCRIPTION: A 53-year-old woman experienced left hemiparesis and alien hand syndrome. A computerized tomography scan showed an infarction in the right frontal lobe, and cerebral angiography revealed a false lumen and intimal flap at the A1 segment of the ACA. Magnetic resonance angiography demonstrated that the stenosis progressed 6 months later and improved 1 year later. Cerebral angiography showed a saccular-like aneurysm 2 years later. The surgery was planned for prevention of aneurysmal rupture. The aneurysm, which was cocoon shaped, was exposed surgically and was resected. Histological examination of the aneurysm showed arterial dissection. The postoperative course was uneventful without additional neurological deficits. CONCLUSION: This is the first case report of A1 dissecting aneurysm presenting with an ischemic event in the literature. The sequential change of the configuration was curious to develop aneurysmal dilatation in 2 years. Long-term follow-up is necessary even after disappearance of the arterial dissection.

Aortic Dissection↗
PubMed2005

Surgical treatment for aneurysmal subarachnoid hemorrhage in the 8th and 9th decades of life.

OBJECTIVE: Industrialized countries are facing a rapid increase of their senior populations. Consequently, the number of elderly patients with aneurysmal subarachnoid hemorrhage is increasing. The purpose of this study was to assess the results of surgical repair for ruptured aneurysm in elderly patients. METHODS: We retrospectively investigated elderly patients (ages 70-89 yr) who were undergoing surgical treatment for ruptured aneurysm during the 15-year period 1988 to 2002 and compared patients in the 8th and 9th decades of life. Generally, patients were treated surgically within 72 hours after ictus. RESULTS: Of the total of 2835 patients, there were 509 patients (18.0% of total patients) in the 8th decade and 99 patients (3.5%) in the 9th decade of life. Because data were incomplete and patients who received ventricular drainage or ventriculoperitoneal shunt without aneurysmal repair were excluded, 449 and 89 patients in the 8th and 9th decades of life, respectively, were analyzed. No differences in sex, preoperative grade, preoperative computed tomographic findings, location of aneurysm, and aneurysm size were observed between the two decades. Preoperative grade and computed tomographic findings were predictors of favorable outcomes in the 8th and 9th decades. Patient age was a significant predictor of outcome in the 8th but not in the 9th decade. CONCLUSION: To the best of our knowledge, this study is the largest series of its kind to date. Advanced age alone does not exclude adequate surgical repair in patients with aneurysmal rupture in the 9th decade of life.

Aged↗
PubMed2004

Pediatric embryonal tumor with epithelial immunophenotype showing absence of hSNF5/INI1 expression.

CASE REPORT: A case of a histologically unclassified brain tumor in a 32-month-old boy is reported. He presented with vomiting, appetite loss, and right motor weakness. MR images revealed a huge mass in the left frontoparietal region that was enhanced after the administration of Gd-DTPA. The mass was removed three times because of its recurrence. RESULTS: Histologically, the tumor was composed largely of small-undifferentiated round cells without any patterns of differentiation. Immunohistochemically, the tumor cells were positive for cytokeratin and focally for epithelial membrane antigen (EMA). Glial fibrillary acidic protein (GFAP), S-100 protein and neuronal markers were negative. Electron microscopic investigations demonstrated no evidence of specific differentiation. MIB-1 staining index was 10-40%. The origin of the tumor was not detected. Expression of the hSNF5/INI1 of this tumor was not detected by reverse transcription-polymerase chain reaction (RT-PCR). The patient has been in a good condition for 7 years after the first operation. CONCLUSIONS: Based on the immunohistochemical findings, the tumor was descriptively diagnosed as an embryonal tumor with an epithelial immunophenotype. The hSNF5/INI1 gene has recently been reported to act as a tumor suppressor in atypical teratoid/rhabdoid tumors. The hSNF5/INI1 gene may lead to tumorigenesis in this case.

Biomarkers↗
PubMed2004

Endovascular therapy versus surgical clipping for basilar artery bifurcation aneurysm: retrospective analysis of 117 cases.

OBJECTIVE: The purpose of this study was to retrospectively evaluate and compare the feasibility, indication and limitations of two treatment options, clipping and coil embolization, for basilar artery (BA) bifurcation aneurysms. MATERIALS AND METHODS: During the last 13 years, 117 patients with 117 BA bifurcation aneurysms were treated exclusively with direct surgery until February 1997, and with either direct surgery or coil embolization therapy since March 1997. Of them, 76 (65%) aneurysms were treated with direct clipping and 41 (35%) were treated with Guglielmi detachable coils (GDCs) embolization. The 76 surgically clipped aneurysms were analyzed on the basis of the pre-operative angiograms as to whether coil embolization would be feasible or not if each case had been attempted. The 41 embolized aneurysms, on the other hand, were analyzed as to whether clipping surgery would be feasible or not if it had been attempted. RESULTS: In the total 117 aneurysms, complete coil obliteration was judged to be possible and simple in 61 (52%) aneurysms, possible with complex techniques (difficult) in 29 (25%) and impossible in 27 (23%). Whereas, complete obliteration with direct clipping was judged to be simple in 66 (57%) aneurysms, difficult in 38 (32%) and impossible in the remaining 13 (11%). Linear correlation as to the technical difficulty was found in 61 (52%) aneurysms, but 14 (12%) had marked discrepancy between the two methods. Of the 76 patients treated with clipping surgery, 17 (22%) were left with some post-operative neurological deficits, and in six out of the 17 aneurysms, embolization might have been simple. There were complications in two patients; one procedure-related and the other with late re-bleeding due to aneurysmal re-growth, in the embolization, group. CONCLUSIONS: Endovascular therapy is an effective alternative for treating BA bifurcation aneurysms, although a quarter of the cases cannot be obliterated completely. It is important to select a suitable treatment option in each case depending on the patient's condition and the angiographical features of each aneurysm as well as the characteristics of the two methods.

Adult↗
PubMed2004

Re-occlusion of the superior sagittal sinus after surgical recanalisation.

A 24-year-old woman was struck on the head by a hammer. Because of early signs and symptoms of intercranial hypertension, she underwent surgery for elevation of the depressed fragments which was compressing the superior sagittal sinus (SSS). After operation, the intracranial pressure (ICP) once decreased, but it gradually increased again. After hypothermia and barbiturate therapy, she recovered fully except for partial visual field defect due to brain contusion. A carotid angiogram 28 days after injury revealed complete occlusion of the whole SSS with good collateral circulation. After brain edema had subsided, a follow-up angiogram revealed normal blood flow through the SSS. Elevation of depressed bony fragments is required for a case presenting with early signs and symptoms of intracranial hypertension due to sinus compression. In a case with severe destruction of the SSS, one needs to know that re-occlusion of the dural sinus may occur after surgical recanalisation.

Adult↗
PubMed2004

Spatial learning transiently disturbed by intraventricular administration of ouabain.

The presence of sodium-potassium-adenosine triphosphatase (Na+,K+-ATPase) on the surface of arachnoid cells indicates that active transport of electrolytes and water occurs there. Previously, we accidentally found that intraventricular administration of TGF-beta1 impaired rat spatial learning. Levels of Na+,K+ -ATPase were decreased in arachnoid cells with fibrosis. To characterize the role of the Na+,K+ -ATPase, Wistar rats were intraventricularly administered a total of 200 microl of ouabain, at concentrations of 10(-5), 10(-4) and 10(-3) M, for one week with an osmotic pump, and were examined with a Morris water maze. Latency for reaching the platform did not significantly differ between ouabain-administered rats and controls. Spatial learning was impaired in a dose-dependent manner. Na+,K+ -ATPase activity of arachnoid cells ceased during ouabain administration, and recovered completely three weeks after the end of ouabain administration. The present results suggest that the Na+,K+ -ATPase on the surface of arachnoid cells contributes to maintenance of rat spatial learning.

Animals↗
PubMed2004

Ruptured distal middle cerebral artery aneurysm.

OBJECT: Ruptured distal middle cerebral artery (MCA) aneurysms are uncommon, and their clinical and radiological features are poorly understood. To clarify characteristics of these lesions, the authors undertook a retrospective analysis of nine patients with ruptured distal MCA aneurysms. METHODS: The medical records of patients who underwent surgical repair of ruptured intracranial aneurysms between 1988 and 2002 at Shinshu University Hospital and its affiliated hospitals were retrospectively evaluated. The authors found only nine patients with a ruptured distal MCA aneurysm, and their clinical, neuroimaging, and intraoperative findings were evaluated. CONCLUSIONS: This study of nine patients with distal MCA aneurysms is the largest series to date. Eight lesions were saccular aneurysms that were clipped and the remaining one was a mycotic aneurysm that was trapped. Eight of the nine patients suffered cerebral hematomas with subarachnoid hemorrhage. All patients had good outcomes after obliteration of their aneurysm, although their preoperative condition was not good.

Aged↗
PubMed2004

Functional role of the Na+/H+ exchanger in the regulation of cerebral arteriolar tone in rats.

OBJECT: In vascular smooth-muscle cells, the Na+/H+ exchanger (NHE) is involved in the regulation of [Na+]i, pHi through [H+], and cell volume. Recently, investigations have determined that this exchanger contributes to ischemia and reperfusion injury in coronary circulation. Nonetheless, there is limited information on this glycoprotein in cerebral circulation, especially microcirculation. Thus, the authors in the present study examined the role of NHE in the regulation of cerebral arteriolar tone and its related mechanisms in vitro. METHODS: The internal diameter of isolated pressurized intracerebral arterioles in rats was monitored with the aid of a microscope. To examine the basal activity of NHE two kinds of Na+/H+ exchange inhibitors (FR183998 and 5-[N,N-hexamethylene]amiloride) were administered in the arterioles. Furthermore the authors studied the effects of nitric oxide (NO) synthase inhibitor (NG methyl-L-arginine), Na+/K+ -adenosine triphosphatase (NKA) inhibitor (ouabain), and the Na+/Ca++ exchange inhibitor (SEA0400) on the vascular response induced by either of the Na+/H+ exchange inhibitors. Both of the Na+/H+ exchange inhibitors constricted the arteriole. Subsequent application of NO synthase inhibitor further decreased the diameter of the arterioles. The Na+/H+ exchange inhibitor-induced constriction was completely abolished in the presence of ouabain and SEA0400. CONCLUSIONS: The NHE is active in the basal condition and regulates cerebral arteriolar tone through NKA and the Na+/Ca++ exchanger. Endogenous NO is not related to the activity of NHE in basal conditions.

Amiloride↗