Biomedical subjects

Eiji Kohmura

Publications and source records attributed to Eiji Kohmura.

At least 19 recordsLinked to original sources

PubMed2007

Delayed onset massive oedema and deterioration in traumatic brain injury.

A 52-year-old man fell from standing and a computed tomography (CT) scan revealed traumatic intracerebral haematoma and subarachnoid haemorrhage in the temporal cortex. He was treated without surgery and discharged. On day 30 after the accident, he had no neurological deficit. On day 37 he complained of headache and urinary incontinence, and on day 39 he was hospitalized due to progressive neurological deterioration (reduced conciousness, dilated pupils, and left hemiplegia). A CT scan revealed a diffuse low-density in the right cerebral hemisphere with marked midline shift. Emergency decompressive craniectomy and right temporal lobectomy were performed. Angiography after surgery revealed moderate vasospasm in the right middle and anterior cerebral arteries. The patient remained severely disabled. Delayed onset neurological deterioration can be caused by brain oedema and vasospasm after traumatic brain injury, despite an intervening period of improvement.

Accidental Falls↗

PubMed2006

Quantification of distension in rat cerebral perforating arteries.

We developed a novel cerebral angiography procedure for rodents using monochromatic synchrotron radiation X-rays and obtained images of rat cerebral perforating arteries for the first time. In normotensive rat, hypercapnia rapidly distended the perforators between 3 and 15 min after induction and major trunk vessels distended more rapidly in 3-6 min. Systemic hypotension made by stepwise hemorrhage distended the perforators up to 158% of control values but constricted most of the large cerebral trunk vessels. In spontaneous hypertensive rats, systemic hypotension-induced distension disappeared in perforators, indicating that perforators with chronic hypertension lose their autoregulatory distensibility.

Animals↗

PubMed2006

In vivo X-ray angiography in the mouse brain using synchrotron radiation.

BACKGROUND AND PURPOSE: We, for the first time, performed in vivo x-ray angiography in the mouse brain using SPring-8, a third-generation synchrotron radiation facility. METHODS: A thin PE-50 tube was placed in the unilateral external carotid artery in adult male C57BL/6J mice. While maintaining the blood flow in the internal carotid artery, 33 muL of contrast agent was injected and then selective angiography of the hemisphere was performed. RESULTS: The average diameters of cerebral artery were as follows: 142.5+/-7.90 microm in middle cerebral artery, 138.3+/-9.35 microm in anterior cerebral artery, 120.5+/-5.53 microm in posterior cerebral artery, and 162.6+/-10.87 microm in internal carotid artery (n=5). To demonstrate the changes in diameter, we induced hypercapnia and detected the dilatation of the vessels between 121% and 124% of the original diameters (n=5). We also repeated angiography in the mice before and after intracarotid injection of vasodilatation drugs papaverine hydrochloride, ATP disodium, and fasudil hydrochloride hydrate and demonstrated the chronological changes in the diameters in each artery at 1, 5, 15, and 30 minutes after injection (n=1 for each drug). CONCLUSIONS: Using only a minimum volume of the contrast agent, synchrotron radiation enables us to study x-ray angiography in the mouse brain. The morphology of the vessels can be clearly observed under physiological conditions. The diameters and their changes can also be successfully studied in vivo.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2006

Synthetic Smac peptide enhances the effect of etoposide-induced apoptosis in human glioblastoma cell lines.

Smac/DIABLO is a mitochondrial protein released into cytosol during the progression of apoptosis. Smac/DIABLO promotes apoptosis by neutralizing the inhibitory effect of the inhibitor of apoptosis proteins (IAPs) on the processing and activity of the effecter of caspase. Here, we generated synthetic Smac peptide which possesses an IAP-binding domain and Drosophila antennapaedia penetration sequence, and examined whether it enhances the effect of the chemotherapeutic agent etoposide in the human glioblastoma cell line. Cellular uptake of Smac peptide in several glioma cell lines was most prominent at 6-12 h after addition. Caspase activity assay showed that our peptide successfully increased the activity of caspase-3 and caspase-9 in etoposide-induced apoptosis. In addition, Smac peptide increased the amount of cleaved PARP (poly ADP-ribose polymerase), but control peptides did not. Moreover, the addition of z-VAD-fmk, a caspase inhibitor, counterbalanced the effect of Smac peptide. Finally, we demonstrated that Smac peptide could enhance the growth inhibition effect of etoposide compared with control peptides. These results suggest that synthetic Smac peptide may be a new molecular targeting anti-tumor therapy for human glioblastoma.

Antineoplastic Agents, Phytogenic↗

PubMed2006

Snoring associated with Ondine's curse in a patient with brainstem glioma.

UNLABELLED: Ondine's curse is an uncommon type of sleep apnea syndrome characterized by failure of automatic respiration. We present an adult patient with brainstem glioma who presented with snoring and Ondine's curse as the only symptoms. CASE REPORT: A 52-year-old female was brought to the hospital by a fellow resident due to exceptionally loud snoring. During the hospitalization, Ondine's curse was diagnosed after monitoring using Apnomonitor 5 (Chest Co., Tokyo), a cheap, non-invasive respiratory monitoring procedure. MRI and MR spectroscopy revealed a brainstem glioma. After radiation therapy, clinical response was documented using repeat apnomonitoring. CONCLUSION: Exceptionally loud snoring in non-obese adult patients with sleep apnea may be an early feature of a brainstem space-occupying lesion. Overnight sleep respiratory evaluation and neuroimaging should be considered in such instances.

Brain Stem Neoplasms↗

PubMed2006

New technique for decompressive duraplasty using expanded polytetrafluoroethylene dura substitute--technical note.

A new technique for decompressive craniectomy with duraplasty was developed for cases in which brain swelling was present at dural closure. Expanded polytetrafluoroethylene (ePTFE) membrane is placed under the dura, covering the brain surface, without the use of sutures. The dura is then loosely sutured. The procedure was used in 13 patients. No leakage of cerebrospinal fluid into the epidural space or signs of infection were observed. Sutureless insertion of an ePTFE membrane at external decompression may increase the ease of duraplasty, decrease operating time, and avoid injury to the brain resulting from suturing the dura. The technique might be especially useful in emergency cases.

Craniotomy↗

PubMed2006

Isolated oculomotor nerve paresis in anaplastic astrocytoma with exophytic invasion.

A 30-year-old man presented with a supratentorial malignant glioma manifesting as isolated progressive left oculomotor nerve paresis. Computed tomography and magnetic resonance imaging showed an intra-axial tumor in the left temporal lobe, extending to the basal and prepontine cisterns, and compressing the brainstem. The tumor was removed subtotally. The histological diagnosis was anaplastic astrocytoma. Malignant glioma with exophytic growth in the temporal lobe should be considered in the differential diagnosis of isolated oculomotor nerve paresis.

Adult↗

PubMed2006

Endovascular treatment for a unusually large mycotic aneurysm manifesting as intracerebral hemorrhage - case report.

A 62-year-old male presented with an unusually large mycotic aneurysm mimicking a saccular aneurysm manifesting as coma and hypotension. Computed tomography showed intracerebral and intraventricular hemorrhage. He was in septic shock due to acute infectious endocarditis. Cerebral angiography disclosed a large distal anterior cerebral artery aneurysm. The diagnosis was mycotic aneurysm based on the morphological features and associated endocarditis. The aneurysm and the parent artery were successfully occluded by endovascular embolization. High-dose antibiotic therapy in the following 6 weeks resulted in resolution of the infectious endocarditis. Early exclusion of ruptured mycotic aneurysm is mandatory because of the high risk of rerupture. Endovascular treatment is an effective alternative for mycotic aneurysms, especially if the patient's general condition is poor. Parent artery occlusion can be safely tolerated if the aneurysm is located distally.

Aneurysm, Infected↗

PubMed2006

Impaired response of perforating arteries to hypercapnia in chronic hyperglycemia.

Diabetes mellitus increases the risk of cerebrovascular disease, the effects of hypercapnia on CBF (cerebral blood flow) and cerebrovascular reactivity during diabetes are still inconsistent. Here, we have established a new microangiographic technique using synchrotron radiation (SPring-8, Japan), which enabled us to visualize rat cerebral vessels with high spatial resolution in real time. The goal of the study presented here was to identify the effects of chronic hyperglycemia on hypercapnia-induced vascular responses (endothelium-dependent vasodilatation) and nitric oxide (NO) donor- induced vascular responses (endothelium-independent) of perforating arteries and of the deeply located large cerebral arteries. We found a significant vasodilatation of rat perforating arteries after hypercapnia with a maximum diameter of approximately 140% of baseline in normal Wistar rats. Chronic hyperglycemia impaired vasodilatation of perforating arteries in genetically diabetic GK rats. SNP (sodium nitroprusside) caused a similar vasodilatation of perforating vessels in normal and chronic hyperglycemia, indicating that endothelium-dependent vasodilatation of perforating arteries may be specifically impaired in chronic hyperglycemia. Possible impairment of endothelium-dependent vasodilatation in perforating vessels during chronic hyperglycemia may cause decreased vascular reserve capacity of perforating artery, resulting in the increased ischemic insults and cerebrovascular diseases in diabetes.

Animals↗

PubMed2006

Carotid artery occlusion and collateral circulation in C57Black/6J mice detected by synchrotron radiation microangiography.

Using monochromatic synchrotron radiation, we performed microangiography in C57BL/6J mice and investigated their vasculature after unilateral and bilateral carotid artery occlusion. Bilateral occlusion of the carotid artery was made by a ligation of the left common carotid artery followed by a ligation of the right internal carotid artery (ICA) two days later (n=12). Five days after the second surgery, angiography was performed. Unilateral occlusion was made by clipping the right ICA and then angiography was performed immediately (n=5). The control mice did not undergo any occlusion (n=5). We removed the brain of the bilateral occlusion mice after angiography and examined the infarction area. The cerebral microvessels in all animals were clearly visualized. In the control mice, the posterior communicating artery (Pcom) was not visualized. In the unilateral occlusion mice, the anastomosis of the pterygopalatine artery (PPA) and the external carotid artery (ECA) were recognized. The PPA is thus considered to play a role in the collateral vessel between the ICA and the ECA. The Pcom was not visualized. In the bilateral occlusion mice, the Pcom was observed either unilaterally (n=5) or bilaterally (n=5). The Pcom supplied blood flow to the anterior circulation from the vertebrobasilar arteries. The bilateral occlusion mice that had at least one visualized Pcom did not have any infarction. We could successfully visualize the cerebral vasculature of normal mice and carotid artery occluded mice in an in vivo study. Microangiography can demonstrate the development of vasculature and the blood flow dynamics in mice.

Angiography↗

PubMed2006

Sca-1 and Thy-1 accelerate neuron-like differentiation in bone marrow stromal cells.

Bone marrow stromal cells taken from EGFP transgenic mice were sorted by magnetic beads with surface markers for Sca-1 and Thy-1. The cells were then co-cultured on organotypic hippocampal slice or with neuronal cell feeder in dish. On hippocampus, both Sca-1 and Thy-1 positive cells showed 4- 8 folds higher potential to show neuron-like morphology than negative cells. In dish, negative cells fewly survived but each positive cells survived and showed neuron-like differentiation. In both culture condition, retinoic acid supplement accelerate differentiation. Differentiated Sca-1 and Thy-1 positive cells were immunohistochemically GFAP- and NeuN-negative but nestin-, neurofilament- and NSE-positive. Neuron-like differentiation of bone marrow cells can be enhanced by selection using cell surface proteins.

Animals↗

PubMed2005

Outcome of surgical clipping for ruptured, low-grade, anterior circulation cerebral aneurysms: should clipping be omitted after International Subarachnoid Aneurysm Trial?

BACKGROUND: A recent randomized trial for ruptured aneurysm resulted in poorer outcomes for the surgical group than the endovascular group. However, the surgical results seemed to be worse than could be expected for experienced neurosurgeons in Japan. We therefore analyzed our own surgical results and evaluated them for a comparison with the trial results. METHODS: Data on patients with ruptured, small, anterior circulation aneurysms in good clinical condition (World Federation of Neurological Surgeons grade I or II) and treated with surgical clipping were obtained from various discharge databases for 1997 to 2001, and their outcomes were analyzed in a retrograde fashion. RESULTS: Of the total of 487 patients, 17.6% showed a poor outcome (modified Rankin Scales 3-6) at discharge, and after 1 year, 6.1% remained in poor clinical condition. However, fewer patients were in poor condition both at discharge and after 1 year compared with the surgical and endovascular results for patients entered in the International Subarachnoid Aneurysm Trial. Complete occlusion of the aneurysm was attained in 93.6% of our patients. Rebleeding from the treated aneurysm occurred in 0.6%, and there was no rebleeding after 1 year. CONCLUSIONS: Surgical clipping is a safe and reliable treatment and can be the first choice for small ruptured aneurysms of the anterior circulation with a good grade.

Adolescent↗

PubMed2005

Aggressive syringomatous carcinoma of the orbit.

A 68-year-old woman with an unusual tumor involving the right orbit presented with painful exophthalmos of the right eye. Excision biopsy of her right eyelid was performed. The specimen showed ductal differentiation with comma-like extensions identical to syringoma. Cellular atypia, an invasive growth pattern, and remarkable perineural invasion led to the diagnosis of syringomatous carcinoma. Magnetic resonance imaging showed that the tumor exhibited maxillary involvement, invading the supraorbital fissure and bone of the middle skull base. The patient underwent craniofacial resection and has been alive with no sign of recurrence for 2 years. This case suggests that wide excision of these tumors with a clear surgical margin using skull base surgical techniques may offer a good prognosis.

Case Reports↗

PubMed2005

Over-expression of Aurora-A targets cytoplasmic polyadenylation element binding protein and promotes mRNA polyadenylation of Cdk1 and cyclin B1.

Aurora-A is a centrosomal serine-threonine kinase that regulates mitosis. Over-expression of Aurora-A has been found in a wide range of tumors and has been implicated in oncogenic transformation. However, how Aurora-A over-expression contributes to promotion of carcinogenesis remains elusive. Immunohistochemical analysis of breast tumors revealed that over-expressed Aurora-A is not restricted to the centrosomes but is also found in the cytoplasm. This over-expressed Aurora-A appeared to be phosphorylated on Thr288, which is known to be required for its enzymatic activation. In analogy to Aurora-A's role in oocyte maturation and the early embryonic cell cycle, here we investigated whether ectopically over-expressed Aurora-A can similarly stimulate polyadenylation of mRNA in human somatic cultured cells by interacting with a human ortholog of cytoplasmic polyadenylation element binding protein, h-CPEB. In vitro experiments revealed that Aurora-A binds directly to, and phosphorylates, h-CPEB. We found that polyadenylation of mRNA tails of cyclin B1 and Cdk1 was synergistically stimulated when Aurora-A and h-CPEB were over-expressed, and they were further promoted in the presence of an Aurora-A activator Ajuba. Our results suggest a function of ectopically over-expressed Aurora-A that might be relevant for carcinogenesis.

Amino Acid Sequence↗

PubMed2005

Involvement of gamma protein kinase C in estrogen-induced neuroprotection against focal brain ischemia through G protein-coupled estrogen receptor.

The neuroprotective effects of estrogen were studied in the ischemic model mice by 90 min transient unilateral middle cerebral artery occlusion (MCAO) followed by 22.5 h reperfusion. The total infarct size in C57BL/6 female mice after MCAO and reperfusion was significantly smaller than that in male mice. Intraperitoneal injection of estrogen after the start of reperfusion significantly reduced the infarct volume in the male mice. However, no significant gender difference was found in total infarct size in gamma protein kinase C (PKC)-knockout mice, suggesting that the neuroprotective effects of estrogen are due to the activation of a specific subtype of PKC, gammaPKC, a neuron-specific PKC subtype, in the brain. We demonstrated that exogenous estrogen-induced neuroprotection was attenuated in gammaPKC-knockout mice. Immunocytochemical study showed that gammaPKC was translocated to nerve fiber-like structures when observed shortly after MCAO and reperfusion. We also visualized the rapid and reversible translocation of gammaPKC-GFP (green fluorescent protein) by estrogen stimulation in living CHO-K1 cells. These results suggest that the activation of gammaPKC through the G-protein-coupled estrogen receptors on the plasma membrane is involved in the estrogen-induced neuroprotection against focal brain ischemia.

Animals↗

PubMed2005

Treatment of cerebral vasospasm with intra-arterial fasudil hydrochloride.

OBJECTIVE: Symptomatic cerebral vasospasm is a major cause of disability and death in patients with aneurysmal subarachnoid hemorrhage. The purpose of this study was to determine the efficacy of intra-arterial infusion (IAF) of fasudil hydrochloride for symptomatic vasospasm in terms of neurological improvement and the angiographic features of cerebral vessels. METHODS: A consecutive series of 23 patients underwent IAF therapy for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Angiographic vasospasm was assessed before and after the IAF treatment. Immediate clinical effect was assessed within 24 hours after the IAF treatment, and the Glasgow Outcome Scale was used to evaluate late clinical outcome at 3 months after the onset. RESULTS: IAF treatment was performed on 34 occasions for 23 patients (16 women, 7 men). Angiographic improvement was observed on all occasions (100%), and immediate clinical improvement was observed on 15 occasions (44.1%). At 3-month follow-up, 15 patients (65.2%) showed good recovery or moderate disability on the Glasgow Outcome Scale. CONCLUSION: IAF therapy was effective in dilating spastic arteries, and clinical improvement was observed in approximately half of the fasudil hydrochloride infusions. Our findings suggested that the IAF therapy was safe and effective for patients with symptomatic vasospasm after subarachnoid hemorrhage.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2005

Comparison of conventional region of interest and statistical mapping method in brain single-photon emission computed tomography for prediction of hyperperfusion after carotid endarterectomy.

OBJECTIVE: Hyperperfusion after carotid endarterectomy (CEA) has been proposed as the main mechanism of intracerebral hemorrhage, which is a disastrous complication. The aim of this study was to compare the predictive value of cerebral blood flow (CBF) abnormalities for hyperperfusion after CEA with the conventional region of interest (ROI) analysis and statistical brain mapping analysis. METHODS: For 46 patients with unilateral carotid stenosis of 70% or more, CBF and cerebral vasoreactivity were investigated with resting and acetazolamide-challenge single-photon emission computed tomography before CEA and 1 day after CEA. Three-dimensional stereotactic surface projection (3-D-SSP) analysis of CBF changes was performed by automatic quantification with a predefined template. RESULTS: Logistic regression analysis demonstrated CBF reduction (z-score) to be the only significant variable for postoperative hyperperfusion on 3-D-SSP with thalamic normalization but no significant variable with the ROI method. Receiver operating characteristic (ROC) analysis demonstrated significant improvement in the predictive value of CBF reduction (z-score) on 3-D-SSP (area under the ROC curve = 0.93) in comparison with the ROI method (area under the ROC curve = 0.78) (P = 0.049). According to the optimal cutoff values provided by ROC analysis, patients were categorized into two groups: Type I (CBF decrease < 20%, n = 23) and Type II (CBF decrease > or = 20%, n = 23) on ROI analysis and Type A (z-score < or = 2, n = 40) and Type B (z-score > 2, n = 6) on 3-D-SSP. There was a significant difference in incidence of hyperperfusion between Type A (1 of 40) and Type B (5 of 6) on 3-D-SSP (P = 0.00003) but not between Type I (1 of 23) and Type II (5 of 23) on ROI analysis. Cerebral vasoreactivity did not show significant value in the prediction of hyperperfusion with either the ROI or the 3-D-SSP method. CONCLUSION: Objective assessment of CBF status, especially baseline CBF reduction (z-score), with automatic quantification by 3-D-SSP with normalization had a higher diagnostic value than conventional ROI analysis to identify patients at risk for hyperperfusion after CEA.

Acetazolamide↗

PubMed2005

Presacral meningocele associated with hereditary sacral agenesis and treated surgically: evaluation in three members of the same family.

OBJECTIVE AND IMPORTANCE: Presacral meningocele in hereditary sacral agenesis is a complex and unusual spinal dysgenetic syndrome. Recognition of the syndromic triad, its natural history, and familial presentation has important practical applications for the management of this disease as well as its complications. CLINICAL PRESENTATION: This report concerns three patients in one family with Currarino syndrome. We detail its clinical presentation, operative management, and outcome and suggest management procedures based on reports in the literature and the results of our surgical techniques, which focus on cases with an "incomplete" triad. INTERVENTION: Three members of the same family, one adult and two children, underwent surgery through the posterior sacral approach tying off the communication between dural sac and anterior meningocele. The adult underwent a second surgical procedure in which a custom-designed surgical technique was used to resolve postoperative cerebrospinal fluid leakage. One of the children underwent an additional posterior sagittal anorectoplasty to remove a presacral teratoma. CONCLUSION: We report a rare occurrence of three familial cases of sacral agenesis accompanied by a presacral mass with various degrees of phenotypic expression and with male dominant transmission. Because of its rarity, the best surgical technique and timing remain an open question especially in cases with incomplete triad syndrome.

Abnormalities, Multiple↗