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Biomedical subjects

Hiroyuki Kinouchi

Publications and source records attributed to Hiroyuki Kinouchi.

At least 19 recordsLinked to original sources
PubMed2006

Unsuccessful tracer injection in radionuclide cisternography revisited.

Since cerebrospinal fluid (CSF) leakage is highlighted as a cause of persistent headache, radionuclide cisternography has been increasingly performed in Japan to confirm the disorder, although the limited ability of the examination should be recognized. We present 3 cases in which failure of a tracer injection was strongly suspected. In 2 cases with chronic symptoms, the tracer appeared to be injected into the epidural space, because of irregular initial accumulation of the tracer and lack of diffusion along the CSF cavity. Another is a case with spontaneous CSF leakage confirmed by MRI, and the tracer was thought to be injected into the leaked fluid accumulated in the spinal epidural space. Tracer in the CSF space rapidly disappeared within several hours in all cases. As such cisternographic images may be misdiagnosed as severe CSF leakage, careful interpretation of images in patients especially with no typical MR findings of CSF leakage is necessary. Excessive tracer clearance from the body suggests such technical failure.

Adult↗
PubMed2006

Subdural effusions in the posterior fossa associated with spontaneous intracranial hypotension.

BACKGROUND: Misdiagnosis of spontaneous intracranial hypotension remains a problem, despite increasing recognition. METHODS: Three patients with spontaneous intracranial hypotension presented with typical findings on lumbar puncture, magnetic resonance (MR) imaging, and radioisotope cisternography. All patients showed subdural effusions in the posterior fossa on axial T2-weighted MR imaging. Axial MR images of 112 patients with other conditions were also screened for this finding. RESULTS: One of three patients had typical orthostatic headache, and the other two had continuous headache. The finding of subdural effusions in the posterior fossa on axial T2-weighted MR imaging disappeared after treatment. Similar findings were found in 14 of 112 patients with other conditions. Most of the patients were over 60 years old or had dementia or previous radiation therapy. CONCLUSIONS: Subdural effusions in the posterior fossa can be identified by T2-weighted axial MR imaging, and are useful for the diagnosis of spontaneous intracranial hypotension and for verifying the effectiveness of treatment.

Adult↗
PubMed2006

[A middle cerebral artery dissecting aneurysm manifesting solely with pain, following a vertebral artery dissecting aneurysm].

A 41-year-old male had presented with severe neck pain and was diagnosed as having a left vertebral artery (VA) dissecting aneurysm. During the observation period, he suddenly suffered from a pain on his left temple. MR imaging revealed neither SAH nor cerebral infarction. MR angiography, computed tomographic (CT) angiography and cerebral angiography showed fusiform dilatation of the M1 portion of the left middle cerebral artery (MCA) which had been normal in the former study. The abnormality of the left MCA normalized on both MR and CT angiography 6 months after the second onset. Because of the chronological change of radiological findings compatible with the symptom, we diagnosed the second episode as a MCA dissecting aneurysm manifesting with isolated pain. Among the previous forty-four MCA dissecting aneurysms, all but one case presented with hemorrhagic or ischemic event. In addition, this is the only case of multiple dissecting aneurysms of VA and MCA manifesting with isolated pain.

Adult↗
PubMed2005

123I-metaiodobenzylguanidine single-photon emission computerized tomography in brain tumors - a preliminary study.

OBJECTIVE: (123)I-metaiodobenzylguanidine (MIBG) has been developed as a functional analog of the neurotransmitter norepinephrine. The success of MIBG as an imaging agent for neural crest tumors is derived from its chemical similarities to norepinephrine. The present study aimed to explore a potential of (123)I-MIBG to differentiate embryonal tumors from other types of brain tumors. METHODS: Sixteen patients with brain tumors including three medulloblastomas, one neuroblastoma, six gliomas, and six meningiomas were examined with single-photon emission computerized tomography (SPECT) using (123)I-MIBG. The (123)I-MIBG uptake of tumors was defined as the ratios of tumor/nontumor (early and delayed T/NT) on SPECT images scanned 30 min and 6 h after intravenous injection of the tracer, respectively. Retention index was calculated as (delayed T/NT - early T/NT)/early T/NT. RESULTS: The T/NT ratios on the early images for embryonal tumors (medulloblastomas and neuroblastoma), gliomas, and meningiomas were 3.2+/-1.7 (mean+/-SD), 1.4+/-0.3, and 1.6+/-0.5, respectively. The early uptake was significantly higher in the embryonal tumors than in gliomas (P<0.05). Delayed T/NT ratios for embryonal tumors were increased compared to the early T/NT ratios, while in contrast delayed T/NT ratios for the other tumors remained low (1.2-1.7). The high retention indices of the embryonal tumors indicate specific uptake of (123)I-MIBG in the tumors. CONCLUSION: Early high accumulation and high retention on delayed imaging may indicate a possibility of (123)I-MIBG SPECT in differentiating embryonal brain tumors from gliomas and meningiomas.

3-Iodobenzylguanidine↗
PubMed2005

Candesartan reduces superoxide production after global cerebral ischemia.

Excessive superoxide production after cerebral ischemia is known to mediate neuronal injury. Angiotensin II type 1 receptor activation results in production of superoxide, but whether angiotensin II type 1 receptor blockade prevents production of superoxide and subsequent neuronal injury after ischemia remains unclear. Normotensive rats received the angiotensin II type 1 receptor blocker, candesartan or only vehicle before induction of global cerebral ischemia. Approximately 30% of the hippocampal CA1 neurons survived in candesartan-treated animals, whereas only 2% of neurons survived in vehicle-treated animals. Superoxide production was significantly less in these vulnerable neurons in candesartan-treated animals than in vehicle-treated animals. Angiotensin II type 1 receptor may have an essential role in superoxide production and subsequent injury in vulnerable neurons after global cerebral ischemia.

Animals↗
PubMed2005

Novel dural closure technique using polyglactin acid sheet prevents cerebrospinal fluid leakage after spinal surgery.

OBJECTIVE: Extradural or subcutaneous cerebrospinal fluid (CSF) leakage is a common complication after spinal surgery and is associated with the risks of poor wound healing, meningitis, and pseudomeningocele. Numerous methods to prevent postoperative CSF leakage are available, but pressure-tight dural closure remains difficult, especially with synthetic surgical membranes. The efficacy of a novel dural closure technique was assessed by detecting extradural or subcutaneous CSF leakage on magnetic resonance imaging. METHODS: The novel dural closure technique using absorbable polyglactin acid sheet and fibrin glue and the conventional procedure using only fibrin glue were evaluated retrospectively by identifying extradural or subcutaneous CSF leakage on magnetic resonance imaging scans in the acute (2-7 d) and chronic (3-6 mo) postoperative stages after spinal intradural surgery in 53 patients. RESULTS: The incidence of extradural and subcutaneous CSF leakage was significantly lower (P < 0.05) in the acute (20%) and chronic (0%) stages using polyglactin acid sheet and fibrin glue in 15 patients compared with that in the acute (81%) and chronic (24%) stages using only fibrin glue in 38 patients. One patient in the fibrin glue-only group required repair surgery for cutaneous CSF leakage. CONCLUSION: The combination of polyglactin acid sheet and fibrin glue can achieve water-tight closure after spinal intradural surgery and can minimize the risk of intractable postoperative CSF leakage. This simple, economical technique is recommended for dural closure after spinal intradural surgery.

Adolescent↗
PubMed2005

[Four cases of spontaneous spinal epidural hematoma].

Spontaneous spinal epidural hematoma (SSEH) is a rare clinical entity. Although approximately 500 cases have been reported, controversy exists concerning timing of the treatment and the validity of decompression surgery. We recently encountered four cases of SSEH. Evacuation of the hematoma was carried out in two patients with severe or persistent neurological deficits. Other two patients were treated conservatively because of the rapid resolution of the symptoms. All four patients improved after the treatment; three patients fully recovered and one patient required rehabilitation for moderate quadriparesis. Many previous reports recommended decompression surgery within 48 hours after the onset, however, one patient in our series fully recovered after surgery 4 days after the onset. We reviewed 183 operative cases of SSEH with incomplete neurological deficits in the literature and found that 93% of the patients who underwent surgery more than 48 hours after symptom onset showed good neurological recovery. Conservative treatment should be undertaken for rapidly improving patients, but surgical intervention should be considered in symptomatic patients regardless of the time from the onset.

Adolescent↗
PubMed2005

Comparison of technetium Tc 99m hexamethylpropyleneamine oxime single-photon emission tomograph with stump pressure during the balloon occlusion test of the internal carotid artery.

BACKGROUND AND PURPOSE: Measuring blood pressure (stump pressure) in the distal internal carotid artery during occlusion of the internal carotid artery is reportedly a reliable safety index with which to predict ischemia following permanent occlusion of the internal carotid artery. We compared the stump pressure during occlusion of the internal carotid artery with single-photon emission CT (SPECT) using technetium Tc 99m hexamethylpropyleneamine oxime (HMPAO). METHODS: Twenty-seven patients underwent the balloon occlusion test. After occlusion of the internal carotid artery was performed by a balloon catheter, technetium Tc 99m HMPAO was injected, and then the balloon remained inflated for 15 minutes. The stump pressure was continuously monitored for those 15 minutes. After the balloon catheter was deflated and removed, SPECT was performed. Sixty-four symmetric pairs of regions of interest were set on both sides of the cerebral hemisphere. The radioactivity count ratio (L/n ratio) of the occluded side to the contralateral normal side was calculated. We defined hypoperfusion as an area with an L/n ratio <0.8. The minimum mean stump pressure (minMSP) during the balloon occlusion test and the pressure ratio of the minMSP to the mean systemic pressure were compared with the hypoperfusion area on SPECT. RESULTS: The number of regions of interest with hypoperfusion was significantly (P < .001) greater in patients with a minMSP <40 mm Hg (mean [+/-SD] = 31.5 +/- 13.7) than in patients with a minMSP > or =40 mm Hg (5.1 +/- 4.0). The number of regions of interest with hypoperfusion was also significantly (P < .001) greater in patients with a pressure ratio <0.5 (26.7 +/- 15.8) than in patients with a pressure ratio > or =0.5 (4.5 +/- 3.5). CONCLUSION: The minMSP during the balloon test occlusion reflects the extent of the hypoperfused area measured by SPECT using technetium Tc 99m HMPAO.

Adult↗
PubMed2004

Prevention of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage by intraoperative cisternal fibrinolysis using tissue-type plasminogen activator combined with continuous cisternal drainage.

The efficacy of intraoperative cisternal irrigation using tissue-type plasminogen activator (tPA) combined with continuous cisternal drainage was assessed for the prevention of symptomatic vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). Seventy consecutive patients underwent direct surgery for aneurysm clipping within 48 hours of SAH and had computed tomography (CT) findings classified as Fisher group III or IV with densities of more than 65 Hounsfield units (HU). Fibrinolysis of the cisternal clots was performed during surgery using 1.6 mg tPA in 55 cases or 3.2 mg tPA in 15 cases. If postoperative CT within 24 hours of surgery showed areas with density more than 65 HU, additional tPA (0.8 mg/day) was administered into the cisternal catheter until the high density areas disappeared. The cisternal drainage catheters were left in place until day 14. Additional tPA injection was necessary in four of the 55 patients receiving 1.6 mg tPA. Symptomatic vasospasm occurred in three patients (4.3%) and two patients had low density areas on CT. Permanent deficit (hemiparesis) due to cerebral vasospasm remained in only one patient. Intraoperative cisternal irrigation with tPA combined with cisternal drainage is safe and effective for the prevention of symptomatic vasospasm following SAH.

Adolescent↗
PubMed2004

Direct repair of a blisterlike aneurysm on the internal carotid artery with vascular closure staple clips. Technical note.

Vascular closure staple clips made of titanium were originally developed for microvascular anastomosis. Clinical applications for these clips include arteriotomy closure for carotid endarterectomy, extracranial-intracranial bypass, and dural closure. This is the first report in which vascular closure staple clips have been used successfully for direct repair of a tear on the internal carotid artery (ICA). This report involves a 65-year-old man who presented with sudden onset of headache. Admission computerized tomography scans demonstrated a diffuse and thick subarachnoid hemorrhage in the basal cisterns. Cerebral angiograms demonstrated a broad-based, small bulge on the superomedial wall of the left ICA. Intraoperatively, an extremely thin-walled aneurysm was seen on the segment of the ICA at the C-2 vertebral level. The aneurysm ruptured abruptly, although no surgical manipulation was being performed on the aneurysm itself. After temporary clips were applied on the vessel, a large tear of the ICA was repaired with vascular closure staple clips. Reconstruction with the vascular closure staple clips required only a short period of temporary occlusion of the ICA. Postoperative angiograms revealed reduction of the aneurysm bulge and good patency of the ICA. The postoperative course was uneventful, and the patient has been free of symptoms. The vascular closure staple clipping procedure is useful for urgent repair of an aneurysm tear. This method is a new treatment option for these fragile aneurysms in cases in which other options, such as encircling clips or bypass procedures, may have drawbacks or be impossible.

Aged↗
PubMed2004

Simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery aneurysms.

OBJECT: The authors of this study evaluated the efficacy of simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery (ICA) aneurysms. METHODS: The endoscopic technique was applied during microsurgery in 11 patients with 13 aneurysms. Nine of these lesions were located on the posterior communicating artery (PCoA), three in the paraclinoid region, and one on the anterior choroidal artery (AChA). Eight patients had unruptured aneurysms and three had ruptured aneurysms. The endoscope was introduced after first exposing the aneurysm through the microscope and was gripped firmly by an airlocked holding arm fitted with a steering system throughout the entire surgery, including dissection of the perforating arteries and application of the aneurysm clips. Regarding paraclinoid aneurysms, clips were applied through direct visualization of the ophthalmic artery and the proximal neck. In a case involving a superior hypophyseal artery aneurysm in the paraclinoid segment, a ring clip was applied without removing the bone structure around the optic canal. In all aneurysms of the PCoA and the AChA, perforating arteries behind the lesion were identified and dissected using endoscopic control. The aneurysm clip was applied in the best position in a single attempt in 10 of 11 patients. There was no surgical complication related to the endoscopic procedures. CONCLUSIONS: Simultaneous monitoring with the microscope and endoscope is extremely useful in applying clips to ICA aneurysms. This combined method allows for direct dissection of the aneurysm, perforating vessels, and the main trunk in an area not visible through the microscope's eyepiece and promises better surgical results.

Adult↗
PubMed2004

[Supratentorial primitive neuroectodermal tumor: report of a surgical case].

We reported a rare case of supratentorial primitive neuroectodermal tumors (sPNET) and reviewed the literature. A 15-year-old girl presented with a one-month history of headache and vomiting. CT scans showed a huge, solid and cystic tumor with calcification, occupying the left anterior cranial fossa. The solid portion of the tumor was hypointense on T1-weighted images, slightly hyperintense on T2-weighted images, hyperintense on diffusion- weighted images, isointense on fluid-attenuated inversion recovery (FLAIR) images, and strongly enhanced after administration of contrast medium. The expansile tumor had a broad attachment to the dura matter of the anterior cranial fossa. The patient underwent an uneventful extirpation of the tumor. Microscopically, the solid tumor contained small, round poorly-differentiated cells with pleomorphic nuclei and brisk mitotic activity. The tumor cells were immunoreactive for synaptophysin and GFAP, whereas lack of MIC2 gene product expression was confirmed using the monoclonal antibody 12E7. The MIB-1-positive rate was 43%. The histological diagnosis was sPNET. Postoperatively, a dose of 30.6Gy was administrated to the whole brain and a boost of 19.6Gy to the T2-hyperintensity lesion. The patient successively received a dose of 30.4Gy to the whole spine and Linac stereotactic radiotherapy with a marginal dose of 16.8Gy at the tumor bed. Three months after radiotherapy the patient received chemotherapy using carboplatin and etoposide. Follow-up MR images showed no evidence of recurrent tumor 5 months after the radiochemotherapy. On the basis of MR findings on both diffusion-weighted and FLAIR images, preoperative diagnosis of sPNET may be important for choosing appropriate therapeutic strategies for this tumor.

Adolescent↗
PubMed2004

[Unusual MR appearance of intracranial dissemination from cervical glioblastoma].

We reported a rare case of cervical glioblastoma with intracranial dissemination at an early stage of clinical course and reviewed the literature. An 8-year-old girl presented with failure of vision 3 months prior to admission to our hospital. Neurological examination on admission disclosed no definitive abnormalities except for bilateral visual disturbance and optic atrophy. Cranial MR images revealed a homogeneously enhancing tumor in the left sylvian fissure. Multiple spotty T2-hyperintensity lesions without contrast enhancement were also disclosed in bilateral cerebellum. Spinal MR images showed an enhancing tumor at C7 and tiny enhancing lesions on the surface of T11. The patient underwent an uneventful excision of the exophytic tumor at C7. The histological diagnosis was glioblastoma. The enhancing tumor in the left sylvian fissure treated by Linac stereotactic radiotherapy with a marginal dose of 38.4Gy in 12 fractions has diminished, whereas the residual tumor at C7 remained unchanged after radiation of 44Gy. In contrast, the multiple spotty lesions without contrast enhancement dispersedly spread in the cerebellum and infiltrated into brain stem despite 4 courses of chemotherapy using ifosfamide, cisplatin, and etoposide. Stereotactic biopsy of the multiple spotty lesions in the cerebellum was performed. Histological examination revealed anaplastic astrocytoma. The patient died 2 weeks after the biopsy despite additional chemotherapy and focal irradiation to the cerebellum. Early detection and selection of optimal therapeutic strategies are important in management of spinal glioblastoma with subarachnoid dissemination, since neuroradiological findings and therapeutic sensitivity are varied according to differentiation of disseminated tumors.

Brain Neoplasms↗
PubMed2004

[A case of pleomorphic TSH-producing pituitary adenoma with calcification].

We reported a rare case of pleomorphic TSH-producing pituitary adenoma with calcification and reviewed the literature. A 25-year-old female was admitted to our hospital with a complaint of anterior neck swelling. An endocrinological examination demonstrated elevated serum levels of free triiodothyronine (FT3: 5.6 pg/ml), free thyroxin (FT4: 2.2 ng/dl), TSH (5.85 microIU/ml), and TSH a-subunit (5.9 ng/ml), whereas a physical examination revealed no goiter. CT scan showed a suprasellar isodensity mass with dense calcification. Contrast-enhanced T1-weighted images revealed a less enhancing tumor extending from the left upper portion of pituitary fossa into suprasellar cistern. The patient underwent gross total removal of the tumor via the right pterional approach. Microscopically, medium-sized to enlarged tumor cells with marked pleomorphism and prominent calcification were observed. The tumor cells displayed positive reaction for TSH (beta-subunit). The MIB-1 index averaged 2.9%. The histological diagnosis was a pleomorphic TSH-producing pituitary adenoma. Postoperatively, the serum levels of FT3, FT4, TSH, and TSH alpha-subunit decreased to normal range. Follow-up MR images showed no evidence of recurrent tumor 3 years after the resection. All of six patients with densely calcified TSH-producing pituitary adenoma, previously reported in the literature, remained well without tumor recurrence. We suggest that this type of TSH-producing pituitary adenoma may be associated with favorable prognosis despite histologically pleomorphic appearance.

Adenoma, Pleomorphic↗
PubMed2003

Induction of heat shock protein 40 and GrpE mRNAs following transient focal cerebral ischemia in the rat.

Cerebral ischemia is associated with the induction of several heat shock proteins (HSPs), but the effects on HSP40 and GrpE are less clear. The present study investigated the induction of Hsp40 and GrpE mRNAs following 30 min of middle cerebral artery occlusion in the rat model. Reverse transcription-polymerase chain reaction (PCR) and in situ hybridization analyses showed significant induction of both mRNAs in the ischemic cortex. These results demonstrate the synergic induction of HSP70 molecular chaperone machinery in cerebral ischemia.

Animals↗
PubMed2003

Oxidative damage to the endoplasmic reticulum is implicated in ischemic neuronal cell death.

The endoplasmic reticulum (ER), which plays important roles in apoptosis, is susceptible to oxidative stress. Because reactive oxygen species (ROS) are robustly produced in the ischemic brain, ER damage by ROS may be implicated in ischemic neuronal cell death. We induced global brain ischemia on wild-type and copper/zinc superoxide dismutase (SOD1) transgenic rats and compared ER stress and neuronal damage. Phosphorylated forms of eukaryotic initiation factor 2 alpha (eIF2 alpha) and RNA-dependent protein kinase-like ER eIF2 alpha kinase (PERK), both of which play active roles in apoptosis, were increased in hippocampal CA1 neurons after ischemia but to a lesser degree in the transgenic animals. This finding, together with the finding that the transgenic animals showed decreased neuronal degeneration, indicates that oxidative ER damage is involved in ischemic neuronal cell death. To elucidate the mechanisms of ER damage by ROS, we analyzed glucose-regulated protein 78 (GRP78) binding with PERK and oxidative ER protein modification. The proteins were oxidatively modified and stagnated in the ER lumen, and GRP78 was detached from PERK by ischemia, all of which were attenuated by SOD1 overexpression. We propose that ROS attack and modify ER proteins and elicit ER stress response, which results in neuronal cell death.

Animals↗
PubMed2003

[Therapeutic results of eight patients with intracranial ependymomas].

Between 1985 and 2001, eight patients with intracranial ependymomas underwent surgery at our hospital. The cases included six infratentorial ependymomas, one supratentorial ependymoma and one supratentorial anaplastic ependymoma. Infratentorial ependymomas were classified according to origin and extension. The lateral type tumors originated from the lateral part of the fourth ventricle in four cases. The midfloor type tumors originated from the inferior half of the fourth ventricular floor in two cases. The three totally resected tumors were the lateral type tumors. The remaining one case with the lateral type tumor underwent nearly total resection of the tumor, since the tumor involved lower cranial nerves. All patients with the midfloor type tumors underwent incomplete resections of the tumors, because the tumors infiltrated into brain stem. Lower cranial nerve involvement and brain stem invasion implied incomplete resection and had the poor prognosis. In intracranial ependymomas, all four patients with total resections have been alive, whereas three of four patients with incomplete resections have died. The mean survival time of all patients with intracranial ependymomas was 127 months from the time of the initial surgery. There were no deaths in the patients with tumors showing MIB-1 index < 10% (n = 4). The mean survival time of the patients with tumors showing MIB-1 index > or = 10% (n = 4), was 30 months. The extent of the resection, the age of the patients and MIB-1 index are important factors in the outcome in patients with intracranial ependymomas. Two representative children aged less than 3 years with the midfloor type tumors were presented. In a patient treated with conventional radiation and chemotherapy, residual tumor repeatedly enlarged within 12 months despite several resections of the tumor. The patient died 32 months after the initial resection. In contrast, the other patient received multidisciplinary treatment including Linac stereotactic radiotherapy (SRT) with a marginal dose of 27 Gy in 9 fractions, have been still alive for 45 months after the initial resection. The residual tumor slightly decreased in size and remained stable without evident growth 12 months after SRT. SRT may provide good local control for patients with intracranial ependymomas and have a favorable impact on survival.

Adolescent↗