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Biomedical subjects

Satoshi Kuroda

Publications and source records attributed to Satoshi Kuroda.

At least 55 records · Page 3Linked to original sources
PubMed2004

Pretreatment and posttreatment evaluation of hemodynamic and metabolic parameters in intracranial dural arteriovenous fistulae with cortical venous reflux.

OBJECTIVE: Retrograde drainage into the cortical veins results in poor outcome in patients with an intracranial dural arteriovenous fistula. However, the pathophysiological features of dural arteriovenous fistulae remain obscure. This study aimed to clarify hemodynamic and metabolic conditions in these patients using positron emission tomography. METHODS: This study included eight patients with an intracranial dural arteriovenous fistula. All patients had cortical venous reflux, as demonstrated by angiography. Regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional cerebral metabolic rate for oxygen, and regional oxygen extraction fraction (rOEF) were measured before and after surgical or endovascular treatment using positron emission tomography. RESULTS: Pretreatment positron emission tomographic studies revealed that all patients had abnormal hemodynamic and metabolic parameters in the area that was drained by the involved cortical veins. A severe increase in rCBV was noted in seven of the eight patients. A significant decrease in rCBF also was observed in all eight patients. A negative correlation was observed between rCBF and rCBV. Three patients had an elevated rOEF. Oxygen metabolism was impaired in seven patients. All patients underwent successful treatment. Follow-up studies demonstrated significant improvements in rCBF, rCBV, and regional cerebral metabolic rate for oxygen. The improvement in regional cerebral metabolic rate for oxygen varied among the patients. Normalization of rOEF also was confirmed in three patients who had increased rOEF before the treatment. CONCLUSION: The present results suggest that hemodynamic and metabolic characteristics vary widely among patients with cortical venous reflux. It is essential to precisely evaluate hemodynamic and metabolic conditions to predict their outcomes and therapeutic effects.

Adult↗
PubMed2004

[A case of jugular phlebectasia: usefulness of color Doppler ultrasonography in the diagnosis].

We present a rare case of jugular phlebectasia, which was able to be diagnosed by a color Doppler sonography. A 69-year-old female patient complained of a painless neck mass on the left side and consulted our hospital. MRI showed a round and regular mass with a diameter of 2.5 cm. B-mode ultrasonography showed a soft, tubular mass in addition to the common carotid artery. In addition, color Doppler sonography revealed a very slow (about 6 cm/sec) turbulent flow in the mass. Valsalva maneuver immediately stopped the slow flow in the mass and increased the diameter. These findings were immediately resolved after the termination of the Valsalva maneuver. The patient was diagnosed as having jugular phlebectasia, and was conservatively followed up. The specific findings of ultrasonography and color Doppler sonography were very useful to diagnose, non-invasively, jugular phlebectasia, a very rare disorder.

Aged↗
PubMed2004

Reduced blood flow and preserved vasoreactivity characterize oxygen hypometabolism due to incomplete infarction in occlusive carotid artery diseases.

UNLABELLED: Recent studies have clarified that hemodynamically compromised patients are at high risk for subsequent stroke. The acetazolamide test is widely used to detect the patients with hemodynamic compromise due to occlusive carotid artery disease. Previous studies have suggested that patients with impaired reactivity to acetazolamide had an increased oxygen extraction fraction (OEF) on PET. However, the underlying pathophysiology has not been defined in patients with reduced blood flow and preserved reactivity to acetazolamide due to carotid occlusive diseases regardless of a normal appearance on MRI. This study aimed to clarify hemodynamic and metabolic parameters in such patients, using (15)O gas and (11)C-flumazenil (FMZ) PET. METHODS: Our study included 15 patients who had reduced cerebral blood flow (CBF) and preserved cerebrovascular reactivity (CVR) to acetazolamide in the ipsilateral middle cerebral artery territory due to occlusive carotid diseases on N-isopropyl-p-(123)I-iodoamphetamine ((123)I-IMP) SPECT. We determined the CBF, cerebral metabolic rate for oxygen (CMRO(2)), cerebral blood volume (CBV), and OEF using (15)O gas PET. The binding potential for (11)C-FMZ was also measured in 5 patients. All patients were medically treated and followed-up during a mean period of 2.7 y. RESULTS: (15)O gas PET scans revealed that the ipsilateral CBF and CMRO(2) were reduced to 80% +/- 11% (P < 0.0001) and 78% +/- 8% (P < 0.0001) of the contralateral side, respectively. However, there was no significant side-to-side difference in the CBV and OEF. The ipsilateral binding potential for (11)C-FMZ was also significantly reduced to 82% +/- 2% of the contralateral side (P < 0.05), being very similar to the asymmetry of the CBF and CMRO(2). No patients suffered further ischemic stroke in the ipsilateral hemisphere during the follow-up period. CONCLUSION: Our results strongly suggest that a reduced CBF and a normal CVR characterize oxygen hypometabolism probably due to ischemia-related neuronal loss-namely, incomplete infarction. Such an ischemic lesion is not hemodynamically compromised and is at very low risk for a subsequent ischemic stroke even if the patient is medically treated.

Acetazolamide↗
PubMed2004

[Complete resolution of radiculopathy due to cervical vertebral artery dissection after intravascular treatment: a case report].

The authors report the case of a rare manifestation by vertebral artery dissection. A 15-year-old boy who presented with left shoulder weakness and numbness of the left arm was admitted to our hospital. Neurological examination on admission revealed muscle weakness of the left deltoid muscle and sensory disturbance of the left C5 area. MRI/MRA and 3D-CT angiography demonstrated an aneurysm-like dilatation of the left vertebral artery mainly at the C4/5 level. Partial thrombosis was noted in the dilated artery. The left vertebral angiogram showed that the second and third portions of the left vertebral artery had a dilated pseudo-lumen due to arterial dissection. The pseudo-lumen of the dissected vertebral artery was largest in diameter at the C4/5 level. The patient successfully underwent proximal occlusion of the dissected vertebral artery using detachable balloon and Guglielmi detachable coils. Proximal vertebral artery occlusion using an intravascular technique was regarded as a non-invasive and effective option for patients with a cervical radiculopathy due to cervical vertebral artery dissection.

Adolescent↗
PubMed2004

[Surgical treatment for cerebral aneurysm after incomplete Guglielmi detachable coil embolization].

The frequency of surgical treatment for intracranial aneurysms that have been incompletely treated by endovascular coiling will increase in time. The authors describe their experience in the following 3 patients. There was one non-ruptured aneurysm and two ruptured ones. The intervals between coiling and surgery were 1, 5, and 10 months. Surgery was indicated because of partial treatment and/or growth of residual neck. Observation during surgery revealed that coils were exposed to the subarachnoid space at the tip of the aneurysm in the cases of ruptured aneurysms. When the residual neck was large enough for the size of the clip blades, there was no need to remove the coils. The coils in the neck were able to be removed when the interval between coiling and surgery was very short, but could not be removed when the interval was prolonged. Intraoperative angiography and reconstructive bypass surgery may be essential in these complex cases. As pointed out previously, the operative approach should be determined by the need for coil removal and the duration since coiling.

Adult↗
PubMed2004

[Joint therapy of a dural arteriovenous fistula in the transverse-sigmoid sinus using surgical excision and direct sinus packing: a case report].

Combined therapy of direct sinus packing and surgical excision for intracranial dural arteriovenous fistula (dAVF) has not been reported in the literature. A 53-year-old male was admitted to our hospital due to sudden onset of seizure and consciousness disturbance. Plain CT scan showed subcortical hematoma in the right temporal lobe. Cerebral angiography revealed dAVF involved in the right transverse and sigmoid sinuses. The lesion was associated with retrograde venous drainage into the right cerebellum, temporal, and occipital lobes. Positron emission tomography (PET) showed typical findings of venous hypertension in the involved areas. MRI also demonstrated a high intensity lesion in the medulla oblongata, suggesting critical venous congestion. First, we aimed to pack the involved sinus through a minor craniotomy, but cannulation into the sinus was impossible probably because of a marked fibrosis in the involved sinus. Then, we completely exposed the involved sinus through craniotomy. Through a microcatheter inserted into the sinus, the lower part of the sigmoid sinus was directly packed, and the remaining lesion was excised. Postoperative course was uneventful. Disappearance of dAVF resolved the findings on PET and MRI. Combined therapy would be a safe, non-invasive, and useful option for patients with a complex intracranial dAVF.

Central Nervous System Vascular Malformations↗
PubMed2003

Source localization of the re-build up phenomenon in pediatric moyamoya disease-a dipole distribution analysis using MEG and SPECT.

OBJECTS: The "re-build up" phenomenon is a pathognomonic finding induced after hyperventilation in pediatric moyamoya disease, and is closely related to ischemic attacks. However, its precise mechanism remains unknown. METHODS: In this study, MEG, MRI, and SPECT were used to clarify its mechanism in 4 children with moyamoya disease. Cerebral blood flow before and after acetazolamide administration was measured. Spontaneous magnetic brain activity was measured using a whole-head MEG system. The quantified dipole distribution was shown on 3D-MRI. RESULTS AND CONCLUSION: The original current dipoles of the "re-build up" slow waves were predominantly located in the deep cortical sulci in the area with impaired reactivity to acetazolamide. The results suggested that the re-build up waves derive from the deep cortical sulci due to the reduction in the cerebral perfusion reserve.

Adolescent↗
PubMed2003

Calcium-induced mitochondrial swelling and cytochrome c release in the brain: its biochemical characteristics and implication in ischemic neuronal injury.

The objective of the present study was to determine the biochemical characteristics of Ca(2+)-induced mitochondrial swelling (mitochondrial permeability transition; mPT) and cytochrome c release in the brain, and to clarify its role in neuronal injury following transient forebrain ischemia. Mitochondria were isolated from rat brain and liver. Changes in mitochondrial volume were measured via light absorbance at 540 nm. Using Western blot analysis, we examined the in vitro release of mitochondrial cytochrome c under these conditions. Transient forebrain ischemia was induced by 5 min occlusion of the common carotid arteries in the gerbil. Cyclosporin A (CsA), a specific mPT blocker, and/or trifluoperazine, a blocker of phospholipase A(2), were given before and 24 h after ischemia. The number of surviving neurons in the hippocampal CA1 sector was counted 7 days after ischemia. Calcium induced a moderate decrease of light absorbance in brain mitochondria, which was inhibited by CsA. However, calcium induced a much larger decrease of light absorbance in liver mitochondria. Calcium induced a moderate release of cytochrome c from brain mitochondria, which was not inhibited by CsA. However, calcium induced the release of a larger amount of cytochrome c from liver mitochondria. Selective neuronal injury due to transient forebrain ischemia was significantly ameliorated by treatment with high-dose CsA. The biochemical properties of Ca(2+)-induced mitochondrial swelling in the brain are different from those in the liver. Cytochrome c is released from brain mitochondria through an mPT-independent mechanism. CsA potentially ameliorates delayed neuronal injury in the hippocampus due to transient forebrain ischemia.

Animals↗
PubMed2003

Descending aorta to carotid bypass for takayasu arteritis as a redo operation.

In Takayasu arteritis recurrent brain ischemia, due to bypass graft failure, is frequent. Redo bypass grafting from the ascending aorta may be at risk if a failing but patent graft that is critical for brain blood flow is present, because partial clamping the ascending aorta may disturb graft flow if the ascending aorta is short. We report such a patient who successfully underwent redo bypass grafting from the descending aorta. In type I Takayasu arteritis, this operation may be valuable because the descending aorta is usually disease free and brain blood flow is maintained during the operation.

Adult↗
PubMed2003

Role of Chlamydia pneumoniae-infected macrophages in atherosclerosis developments of the carotid artery.

Chlamydia pneumoniae (C. pneumoniae) infection has been recently accepted as an important cause of atherosclerosis. However, the precise mechanisms remain unclear. The present study was aimed to clarify the distribution link among C. pneumoniae, chlamydial HSP 60, and activated macrophages. Atheromatous carotid plaques were obtained from 40 consecutive carotid endarterectomies (CEA). The specimens were prepared for HE and elastica-van Gieson staining. Parallel sections were stained immunocytochemically with monoclonal antibodies for a C. pneumoniae-specific antigen, chlamydial HSP 60, activated macrophages, and smooth muscle cells. Immunoreactivity for the C. pneumoniae-specific antigen was observed within the endothelial cells, activated macrophages, and smooth muscle cells in 36 of 40 specimens (90%). Chlamydial HSP 60 was found in all specimens positive for the C. pneumoniae-specific antigen, and mainly co-localized with the C. pneumoniae-specific antigen within the activated macrophages. The present results suggest that C. pneumoniae is a key microbial organ that causes atheroma developments in the carotid artery. Chlamydia pneumoniae-infected macrophages may come into the arterial intima and mediate inflammatory and autoimmune processes through the production of chlamydial HSP 60, leading to atherosclerosis.

Aged↗
PubMed2003

Migration and differentiation of nuclear fluorescence-labeled bone marrow stromal cells after transplantation into cerebral infarct and spinal cord injury in mice.

There is increasing evidence that bone marrow stromal cells (BMSC) have the potential to migrate into the injured neural tissue and to differentiate into the CNS cells, indicating the possibility of autograft transplantation therapy. The present study was aimed to clarify whether the mouse BMSC can migrate into the lesion and differentiate into the CNS cells when transplanted into the mice subjected to focal cerebral infarct or spinal cord injury. The BMSC were harvested from mice and characterized by flow cytometry. Then, the BMSC were labeled by bis-benzimide, a nuclear fluorescence dye, over 24 h, and were stereotactically transplanted into the brain or spinal cord of the mice. The cultured BMSC expressed low levels of CD45 and high levels of CD90 and Sca-1 on flow cytometry. A large number of grafted cells survived in the normal brain 4 weeks after transplantation, many of which were located close to the transplanted sites. They expressed the neuronal marker including NeuN, MAP2, and doublecortin on fluorescent immunohistochemistry. However, when the BMSC were transplanted into the ipsilateral striatum of the mice subjected to middle cerebral artery occlusion, many of the grafted cells migrated into the corpus callosum and injured cortex, and also expressed the neuronal markers 4 weeks after transplantation. In particular, NeuN was very useful to validate the differentiation of the grafted cells, because the marker was expressed in the nuclei and was overlapped with bis-benzimide. Similar results were obtained in the mice subjected to spinal cord injury. However, many of the transplanted BMSC expressed GFAP, an astrocytic protein, in injured spinal cord. The present results indicate that the mouse BMSC can migrate into the CNS lesion and differentiate into the neurons or astrocytes, and that bis-benzimide is a simple and useful marker to label the donor cells and to evaluate their migration and differentiation in the host neural tissues over a long period.

Animals↗
PubMed2003

Uncleaved legumin in developing maize endosperm: identification, accumulation and putative subcellular localization.

While identifying proteins present in the cytoskeleton and protein body fractions from maize (Zea mays L.) endosperm, a 51 kDa protein was discovered in a fraction containing small (approximately 200 nm in diameter) protein bodies. Based on partial amino acid sequences of V8 protease fragments, degenerate primers were made and fragments of cDNA encoding these partial sequences were cloned. Using 3' and 5' PCR, a full-length cDNA encoding this 51 kDa protein was obtained, which was identified as legumin-1. In other plants, this protein is generally cleaved into 20 and 35 kDa subunits after synthesis. However, SDS-PAGE of both the native and denatured protein indicates that cleavage does not occur in corn endosperm, even though the cleavage site (asparagine) is conserved. The lack of cleavage is presumably because the canonical cleavage sequence downstream from the cleavage site is almost totally absent. levels of transcript and encoded protein were compared in all three varieties and it was shown that both are more abundant in wild-type maize than in opaque-2 or sweet corn. Finally, using TEM, it was shown that the protein apparently occurs in morphologically distinct protein bodies, very similar to the protein bodies in legumes.

Amino Acid Sequence↗
PubMed2003

[Subclavian steal syndrome associated with the right aortic arch in a patient with Peutz-Jeghers syndrome: case report].

We report an adult case who presented vertigo attacks due to subclavian steal syndrome associated with the right aortic arch in a patient with Peutz-Jeghers syndrome. A 29-year-old male diagnosed as having Peutz-Jeghers syndrome developed frequent vertigo attacks and was admitted to our hospital. Blood pressure of the left arm was 20 mmHg lower than that of the right arm. Aortagraphy showed that he had a right aortic arch and isolation of the left subclavian artery. Right vertebral angiography opacified the left vertebral artery and the subclavian artery in retrograde fashion, suggesting subclavian steal phenomenon. Blood flow studies disclosed impaired reactivity to acetazolamide in the bilateral cerebellar hemispheres. We successfully carried out left common carotid artery-transverse cervical artery bypass. Postoperative angiography confirmed the patency of the graft and the disappearance of subclavian steal phenomenon. Vasoreactivity to acetazolamide normalized in the cerebellum. Vertigo attacks were not noted during the one-year follow-up period.

Adult↗
PubMed2003

[Clinical manifestations of infantile moyamoya disease].

PURPOSE: The present study aimed to clarify clinical manifestations of infantile moyamoya disease by comparing them with those of schoolchild moyamoya disease. SUBJECTS AND METHODS: This study included a total of 55 patients who were diagnosed as moyamoya disease on cerebral angiography. Their medical records were precisely evaluated. CT or MRI was performed to examine the location of cerebral infarction in all subjects. Cerebral blood flow was measured in 33 patients before surgery, using the 133-xenon inhalation method and single photon emission computed tomography (SPECT). Postoperative full-scale IQ (FSIQ) was also examined. RESULTS: Of 55 patients, onset age was < 6 yr in 32 (infantile group) and > or = 6 yr in 23 (schoolchild group). Completed stroke was significantly more frequent in the infantile group than in schoolchild group (p = 0.0014). Incidence of cerebral infarct was also higher in the infantile group than in the schoolchild group (p = 0.0023). PCA stenosis/occlusion was observed in 14 of 32 infantile patients, but only in 4 of 23 schoolchild patients (p = 0.0474). Mean cerebral blood flow value was significantly lower than control value in the infantile group, but not in the schoolchild group. The effect of bypass surgery on cerebral ischemic attack was satisfactory in both groups. However, the postoperative FSIQ value was significantly lower in the infantile group than in the schoolchild group (p = 0.0452). CONCLUSIONS: The present study showed that infantile moyamoya disease involves a higher risk for cerebral infarct and completed stroke due to its more advanced stage, and that earlier diagnosis and treatment should be performed to improve the mental prognosis of patients.

Adolescent↗
PubMed2003

[Clinical features and outcomes of 10 asymptomatic adult patients with moyamoya disease].

Recent development of non-invasive diagnostic technology, such as magnetic resonance imaging (MRI) and angiography (MRA), is believed to have made possible on increase in the diagnoses of asymptomatic moyamoya disease. However, no criteria have been established for the management of such cases. The present study aimed to clarify the natural history of asymptomatic moyamoya disease retrospectively. Ten patients were included in this study. None of them had experienced any episode due to moyamoya disease and were only incidentally diagnosed as having moyamoya disease. There were 4 males and 6 females. Their ages ranged from 30 to 67 years, with the mean age of 46.2. Cerebral angiography showed there was the tendency of disease progression in elder patients. MRI detected cerebral infarction in 3 of 10 patients (30%). Hemodynamic ischemia, such as impaired reactivity to acetazolamide and/or elevated oxygen extraction fraction, was observed in 4 of 10 patients. Only one patient underwent surgical revascularization. Antiplatelet or anticonvulsant medication was administered in 5 of 10 patients. The mean follow-up period was 4.1 years, ranging from 0.5 to 13 years. During follow-up periods, the moyamoya lesion markedly progressed and caused cerebral infarction in one patient. However, neither ischemic nor hemorrhagic stroke occurred in the other 9 patients. Multi-center nation-wide study should be planned to clarify the natural course of asymptomatic moyamoya disease and establish the management guidelines for patients with asymptomatic moyamoya disease.

Adult↗
PubMed2003

[Normalization of cerebral hemodynamics and metabolism after carotid stenting in patients unfit for major surgery].

There is increasing evidence that stenting is a useful strategy for internal carotid artery (ICA) stenosis in patients unfit for drastic surgery. However, it should be remembered that perioperative complications including seizure or intracerebral hemorrhage due to hyperperfusion are not so rare. The authors describe a case with severe ICA stenosis, who successfully underwent stenting as a result of intensive medical care for postoperative hyperperfusion. A 77-year-old man with a recent history of angina pectoris and transient ischemic attack was referred to our hospital. Cerebral angiography showed subtotal occlusion of the left ICA. SPECT/PET studies revealed a disturbed reactivity to acetazolamide and an increase in regional oxygen extraction fraction in the left hemisphere, suggesting a marked reduction in cerebral perfusion pressure. He successfully underwent carotid stenting. Intraoperative near-infrared monitoring showed an increase in the concentration of total and oxidized hemoglobin in the left frontal area after stenting. A SPECT study just after stenting also demonstrated hyperperfusion in the left middle cerebral artery territory. His blood pressure was carefully controlled to avoid "hyperperfusion syndrome" including headache, seizure and intracerebral hemorrhage. Follow-up SPECT/PET studies showed a normalization of hemodynamic and metabolic parameters. SPECT/PET studies are quite valuable to predict and prevent hyperperfusion syndrome after carotid stenting, and result in good clinical outcome.

Aged↗
PubMed2002

Surgical treatment of intracranial dural arteriovenous fistulas.

BACKGROUND: When considering the treatment strategies for dural arteriovenous fistulas (DAVFs), it is important to clarify the exact location of the fistula and venous drainage route from both DAVFs and normal brain tissue. DAVFs with leptomeningeal retrograde venous drainage carry a high risk of neurological deficits and require aggressive treatment. When AVFs involve the dural sinus, transvenous embolization via the transfemoral approach is usually the first choice of treatment. For DAVFs draining directly into the cortical veins without dural sinus involvement, transarterial embolization may be a curative treatment. However, when embolization is technically difficult or results in incomplete occlusion, surgical treatment is required. The purpose of the present study was to review our experience with surgical treatment of DAVFs. METHODS: The present series included 17 patients; 9 had DAVFs involving the dural sinus with leptomeningeal retrograde venous drainage and 8 had DAVFs draining directly into the cortical veins. For DAVFs involving the sinus, embolization of the diseased sinus by direct surgical exposure was performed in 8 patients, and surgical excision in one. For DAVFs draining directly into the cortical veins, interruption of the draining veins close to DAVFs was undertaken in 7 and surgical excision in 1. RESULTS: Complete obliteration of DAVFs was demonstrated in 16 patients. At final follow-up, 15 patients were asymptomatic and the other 2 showed clinical improvement. CONCLUSIONS: For DAVFs involving the dural sinus, direct operative sinus packing is indicated. For DAVFs directly draining into the cortical veins, surgical interruption of the draining veins is indicated.

Adult↗