Biomedical subjects

Shunro Endo

Publications and source records attributed to Shunro Endo.

At least 19 recordsLinked to original sources

PubMed2006

Enzymatic and biochemical properties of a novel human serine dehydratase isoform.

A cDNA clone similar to human serine dehydratase (SDH) is deposited in the GenBank/EMBL databases, but its structural and functional bases remain unknown. Despite the occurrence of mRNA, the expected protein level was found to be low in cultured cells. To learn about physicochemical properties of the protein, we expressed the cDNA in Escherichia coli, and compared the expressed protein with that of a hepatic SDH. The purified protein showed l-serine and l-threonine dehydratase activity, demonstrating to be an isoform of SDH. However, their Km and Vmax constants were different in a range of two-order. Removal of Pro128 from the hepatic SDH consisting of 328 residues, which is missing in the corresponding position of the isoform consisting of 329 residues, significantly changed the Michaelis constants and Kd value for pyridoxal 5'-phosphate, whereas addition of a proline residue to the isoform was without effect. These findings suggest the difference in the structures of the active sites of the two enzymes. Another striking feature was that the expressed level of the isoform in E. coli was 7-fold lower than that of the hepatic SDH. Substitution of Val for Leu287 in the isoform dramatically increased the protein level. The high yield of the mutated isoform was also confirmed by the in vitro transcription and translation experiment. The poor expression of the isoform could be explained by the more stable secondary structure of the mRNA than that of the hepatic SDH mRNA. The present findings may provide a clue as to why the protein level in cultured cells is low.

Amino Acid Sequence↗

PubMed2006

Verbal memory deficits in a preadolescent case of lesions of the left parahippocampal gyrus associated with a benign tumor.

The authors report cognitive functions of a 13-year-old boy with a cavernous angioma occupying the posterior left parahippocampal gyrus (PHG) and part of the left fusiform gyrus but not hippocampus. Neuropsychological examinations soon after the removal of the tumor showed selective deficits in semantic memory function, as evaluated by the Category Fluency Task and the Wechsler Memory Scale-Revised, while visual memory, attention, and IQ were not affected. These observations suggest the involvement of the PHG in the processing of semantic memory and provide an insight into the neural substrates underlying the distinct cognitive deficits in some of the psychiatric diseases such as schizophrenia.

Adolescent↗

PubMed2006

Warning headache of subarachnoid hemorrhage and infarction due to vertebrobasilar artery dissection.

OBJECTIVES: The authors describe the clinical features of headache in patients with vertebrobasilar artery dissection (VBAD) and emphasize the importance of recognition of warning headaches preceding subarachnoid hemorrhage. Headache in VBAD is already recognized, but the natural history and clinical features of the warning headache have not been well elucidated. METHODS: The clinical features of 30 patients with VBAD were analyzed retrospectively. RESULTS: Of the 30 VBAD patients, 16 presented with subarachnoid hemorrhage and 14 with ischemia. Headache (without any other symptoms or signs) was detected in 70% of patients with subarachnoid hemorrhage and 50% of patients with infarction. The headache started acutely, was localized to the occiput or nape of the neck, was sharp and severe in intensity, and was different from any previously experienced headaches. The interval from onset of headache to diagnosis of subarachnoid hemorrhage or infarction was 1 to 10 days. Three patients had sudden severe warning headaches without any evidence of subarachnoid hemorrhage at initial presentation and deteriorated within 24 hours due to subarachnoid hemorrhage, demonstrated later on computed tomography. Angiographic findings of patients with warning headaches were nonspecific compared with those of patients without headache. CONCLUSIONS: The present study confirms a high frequency of headache in patients with VBAD. Sudden severe occipital and nuchal pain, even without subarachnoid hemorrhage or any neurologic deficit, should be considered as a warning sign of subarachnoid hemorrhage. Computed tomography, magnetic resonance imaging, and magnetic resonance angiography should be performed urgently for screening of patients with a warning headache to prevent resultant life-threatening major vascular events.

Aged↗

PubMed2006

Safe removal of glioblastoma near the angular gyrus by awake surgery preserving calculation ability--case report.

A 67-year-old patient presented with progressive agraphia, alexia, and impaired ability to calculate persisting for 4 weeks. He showed preserved ability to do single-digit addition and subtraction. Magnetic resonance imaging demonstrated a tumor in the left parietal lobe. A malignant glioma was suspected, and awake craniotomy was performed to remove the tumor with functional cortical mapping to determine the cortices involved in calculation and language. His calculation ability was mapped on the angular gyrus, and partial resection of the tumor was achieved without deterioration of that ability. The histological diagnosis was glioblastoma multiforme. The patient's calculation ability improved dramatically after the operation.

Aged↗

PubMed2006

Transparent endoscopic sheath and rigid-rod endoscope used in endoscopic third ventriculostomy for hydrocephalus in the presence of deformed ventricular anatomy.

OBJECT: Endoscopic third ventriculostomy (ETV) has been widely performed for the treatment of noncommunicating hydrocephalus. In cases of hydrocephalus in conjunction with deformed and complex ventricular anatomy, it is preferable to use a rigid-rod endoscope for ETV, because the excellent visibility provided by this instrument yields a smooth and correct orientation in the ventricle. The authors report on ETV procedures in which they used a transparent endoscopic sheath that has a common channel in which a rigid-rod endoscope and an instrument can be inserted. METHODS: In 15 cases of noncommunicating hydrocephalus, a transparent endoscopic sheath and a rigid endoscope were used for ETV. In 11 of the 15 patients, the diameter of the foramen of Monro and the width of the third ventricle were greater than 5 mm, and thus a transparent endoscopic sheath and a rigid endoscope could be smoothly introduced through the foramen of Monro and an ETV successfully performed. Four patients had congenital or acquired narrowing of the foramen of Monro and an anatomically deformed ventricular system. In three of the patients, opening of the narrowed foramen and an ETV were successfully performed using the transparent endoscopic sheath under direct visualization through the rigid-rod endoscope. CONCLUSIONS: A transparent endoscopic sheath increases safety by offering a corridor to the third ventricle. It also provides excellent visibility without troublesome bleeding from tissues surrounding the foramen of Monro during endoscopic procedures in which a rigid endoscope is used.

Adolescent↗

PubMed2006

[A case of infundibular dilatation developed into an aneurysm and rupturing after the rupture of an aneurysm 10 years ago].

A 44-year-old female with subarachnoid hemorrhage caused by the left internal carotid-posterior communicating artery aneurysm rupture was presented. At that time, carotid angiography showed the left internal carotid-posterior communicating artery aneurysm and the right internal carotid-posterior communicating artery portion infundibular dilatation. Neck clipping for left internal carotid-posterior communicating artery aneurysm was done and she was discharged from our hospital without neurological deficit. After 10 years, she suffered a second subarachnoid hemorrhage. Carotid angiography demonstrated the right internal carotid-posterior communicating artery aneurysm developed from the opposite infundibular dilatation. Emergency clipping was performed with three Sugita fenestration clips, because that aneurysm had a very wide neck. We should examine the internal carotid-posterior communicating artery infundibular dilatation with opposite side aneurysms in young females carefully and serially.

Adult↗

PubMed2006

[Cognitive function in patients with severe carotid stenosis--evaluation of RBANS, WAIS-R and NART before treatment of carotid revascularization--].

PURPOSE: To evaluate the cognitive function in preoperative patients with severe carotid stenosis. PATIENTS AND METHOD: Twenty-five patients with severe carotid stenosis were examined on their cognitive function by RBANS (Japanese version), WAIS-R (Japanese version), and NART (Japanese version) before treatment of carotid revascularization (endarterectomy or stenting). They had full activities of daily living without any hemiparesis, aphasia, agnosia, and apraxia at the time of the examinations. RESULTS: Mean intelligent quotient (IQ) measured by WAIS-R and NART was 104.0 +/- 10.7 and 101.3 +/- 13.4, (ns) respectively. Mean total scale of RBANS was 90.0 +/- 13.4, which was significantly lower than both the results of WAIS-R and NART. A mean value of each RBANS index was 91.3 +/- 11.7 in immediate memory, 102.0 +/- 18.2 in visuospatial/constructional, 93.2 +/- 8.7 in language, 84.6 +/- 14.7 in attention, and 92.1 +/- 14.4 in delayed memory. RBANS index significantly declined in immediate memory, language, attention and delayed memory than visuospatial/constructional. CONCLUSIONS: Qualitative evaluation was available in RBANS, WAIS-R, and NART, which enabled the investigators to make a precise comparison between these methods. WAIS-R and NART showed a comparatively preserved function and were presumed to be useful for the evaluation of the baseline of cognitive function in preoperative patients. RBANS demonstrated a slight decrease in memory and attention in those patients and was expected to be useful to detect the cognitive dysfunction when compared with WAIS-R and NART.

Activities of Daily Living↗

PubMed2005

Adenovirus-mediated expression of heparin cofactor II inhibits thrombin-induced cellular responses in fibroblasts and vascular smooth muscle cells.

Heparin cofactor II functions as a physiological inhibitor of thrombin activity. The rate of inactivation of thrombin by heparin cofactor II is increased in the presence of dermatan sulfate, which is produced by fibroblasts or smooth muscle cells. To elucidate the role of heparin cofactor II in the extravascular cells, we induced expression of heparin cofactor II in cultured human fibroblasts or vascular smooth muscle cells using adenovirus-mediated gene transfer. After infection of adenovirus vector, these cells secreted heparin cofactor II protein into culture medium. The expressed heparin cofactor II formed the complex with exogenous thrombin and inhibited the proteolytic activity of thrombin. Expression of heparin cofactor II by infection of adenovirus vector inhibited thrombin-induced tissue-type plasminogen activator and interleukin-6 releases from fibroblasts and thrombin-induced interleukin-6 release from vascular smooth muscle cells. These findings show that fibroblasts and vascular smooth muscle cells expressing heparin cofactor II are resistant to thrombin-induced cellular responses.

Adenoviridae↗

PubMed2005

Place-related neural responses in the monkey hippocampal formation in a virtual space.

Place cells in the rodent hippocampal formation (HF) are suggested to be the neural substrate for a spatial cognitive map. This specific spatial property of the place cells are regulated by both allothetic cues (i.e., intramaze local and distal cues) as well as idiothetic sensory inputs; the context signaled by the distal cues allows local and idiothetic cues to be employed for spatial tuning within the maze. To investigate the effects of distal cues on place-related activity of primate HF neurons, 228 neurons were recorded from the monkey HF during virtual navigation in a similar situation to a rodent water maze, in which distal cues were important to locate the animal's position. A subset of 72 neurons displayed place-related activity in one or more virtual spaces. Most place-related responses disappeared or changed their spatial tuning (i.e., remapping) when the arrangements of the distal cues were altered/moved in the virtual spaces. These specific features of the monkey HF might underlie neurophysiological bases of human episodic memory.

Animals↗

PubMed2005

Inhibition of cellular proliferation and induction of apoptosis by curcumin in human malignant astrocytoma cell lines.

Nuclear factor (NF)-kappaB is known to control cellular proliferation and apoptosis. In malignant astrocytoma cells, it was reported that NF-kappaB was activated aberrantly and promoted their proliferation. Thus, inhibition of NF-kappaB activity is considered to be a promising therapeutic strategy for malignant astrocytoma. Recently, curcumin, the major constituent of turmeric, was reported to inhibit NF-kappaB activity. In this study, we investigated inhibitory effects of curcumin on NF-kappaB activity and cellular proliferation, and induction of apoptosis by curcumin in human malignant astrocytoma cell lines. Alteration of NF-kappaB activity in NP-2 human malignant astrocytoma cell line after treatment with curcumin was examined using electrophoretic mobility shift assay. Alterations of DNA synthesis and cellular growth in five human malignant astrocytoma cell lines after treatment with curcumin were examined using [(3)H]thymidine incorporation assay and the trypan blue dye exclusion method, respectively. Induction of apoptosis by curcumin in NP-2 and NP-3 human malignant astrocytoma cell lines was examined by DNA-fragmentation analysis and morphological observation. We found that the NF-kappaB activity in NP-2 was significantly reduced by curcumin. The DNA synthesis and the cellular growth were inhibited by curcumin in dose-dependent manner in all the five malignant astrocytoma cell lines. Nuclear condensation and fragmentation, and DNA fragmentation were observed in both NP-2 and NP-3 after the treatment with curcumin. These results indicate that curcumin inhibits the cellular proliferation and induces apoptosis in human malignant astrocytoma cell lines. These results are considered to be resulted from the inhibition of NF-kappaB activity by curcumin.

Antineoplastic Agents↗

PubMed2005

Multiple aneurysms arising from the origin of a duplication of the middle cerebral artery.

Duplication of the middle cerebral artery is an anomalous vessel arising from the internal carotid artery. There have only been 14 reports of aneurysms arising from the origin of a duplication of the middle cerebral artery and 5 of these patients had multiple aneurysms. Aneurysms at this site have a high rupture rate compared to aneurysms in other locations and aggressive management is indicated.

Aged↗

PubMed2005

Case report: acute subdural hematoma due to angiographically unvisualized ruptured aneurysm.

BACKGROUND: We report a case of acute subdural hematoma (SDH) due to angiographically unvisualized ruptured aneurysm. CASE DESCRIPTION: A 57-year-old man presented with sudden-onset headache and nausea. Computed tomography revealed right acute SDH and cerebral angiography revealed no abnormal vessels, but at operation, we found an aneurysm arising from the precentral artery causing an acute SDH. CONCLUSION: In a case of spontaneous acute SDH, the possibility of a cortical artery aneurysm should be considered even if no aneurysm is recognized at angiography.

Acute Disease↗

PubMed2005

Isolation of an antiviral polysaccharide, nostoflan, from a terrestrial cyanobacterium, Nostoc flagelliforme.

A novel acidic polysaccharide, nostoflan, was isolated from a terrestrial cyanobacterium, Nostoc flagelliforme. Nostoflan exhibited a potent anti-herpes simplex virus type 1 (HSV-1) activity with a selectivity index (50% cytotoxic concentration/50% inhibitory concentration against viral replication) of 13,000. Sugar composition and methylation analyses revealed that it was mainly composed of -->4)-D-Glcp-(1-->, -->6,4)-D-Glcp-(1-->, -->4)-D-Galp-(1-->, -->4)-D-Xylp-(1-->, D-GlcAp-(1-->, D-Manp-(1--> with a ratio of ca. 1:1:1:1:0.8:0.2. Two pyridylaminated oligosaccharides were prepared by partial acid hydrolysis and pyridylamination. On the basis of MALDI-TOF-MS and NMR analyses, they were found to be beta-D-Glcp-(1-->4)-D-Xyl-PA and beta-D-GlcAp-(1-->6)-beta-D-Glcp-(1-->4)-D-Gal-PA. From these results, nostoflan might be mainly composed of the following two types of sugar sequence: -->4)-beta-D-Glcp-(1-->4)-D-Xylp-(1--> and -->4)-[beta-D-GlcAp-(1-->6)-]-beta-D-Glcp-(1-->4)-D-Galp-(1-->. Besides anti-HSV-1 activity, nostoflan showed potent antiviral activities against HSV-2, human cytomegalovirus, and influenza A virus, but no activity against adenovirus and coxsackie virus was observed. Therefore, nostoflan has a broad antiviral spectrum against enveloped viruses whose cellular receptors are carbohydrates. Furthermore, nostoflan showed no antithrombin activity, unlike sulfated polysaccharides.

Adenoviridae↗

PubMed2005

Endoscopic aqueductal stenting via the fourth ventricle under navigating system guidance: technical note.

OBJECTIVE: We report three patients with symptomatic isolated fourth ventricle after ventriculoperitoneal shunt placement for hydrocephalus associated with ventricular hemorrhage. All three patients were treated successfully with our new method of endoscopic aqueductal stenting under navigating system guidance. METHODS: A therapeutic rigid endoscope was inserted through the thin cerebellar hemisphere, and endoscopic aqueductal stenting was performed via the enlarged fourth ventricle under navigating system guidance. RESULTS: All three patients underwent successful procedures with good outcomes. CONCLUSION: Our method of aqueductal stenting is a reasonable choice for initial treatment of patients with isolated fourth ventricle, and it entails less invasive neurosurgery.

Cerebral Aqueduct↗

PubMed2005

Lower incidence of symptomatic vasospasm after subarachnoid hemorrhage owing to ruptured vertebrobasilar aneurysms.

OBJECTIVE: In this study, we evaluated the difference in incidence of symptomatic vasospasm between ruptured aneurysms in the anterior and posterior circulation using multiple logistic regression analysis. METHODS: A total of 145 consecutive patients who underwent surgery for aneurysms within 72 hours after subarachnoid hemorrhage (SAH) were studied. RESULTS: The ruptured aneurysm was in the anterior circulation in 128 patients (88.3%) and in the posterior circulation in 17 patients (11.7%). Forty patients (27.6%) had symptomatic vasospasm and 105 patients (72.4%) did not. Univariate and multivariate analyses were performed to assess relationships among various variables and the occurrence of symptomatic vasospasm after SAH. Finally, Grade III to V (Hunt and Hess grade) and Group 3 (Fisher's classification) on admission were found to be independently positively associated with the occurrence of symptomatic vasospasm while ruptured vertebrobasilar aneurysm were negatively associated. CONCLUSION: Although a poor clinical grade and a severe SAH classification on admission such as Hunt and Hess grade and Fisher's classification are established powerful predictors of symptomatic vasospasm, ruptured vertebrobasilar aneurysm are for the first time reported to be a predictor of symptomatic vasospasm based on results of a recent reliable statistical analysis.

Aged↗

PubMed2005

Duration of cerebrospinal fluid drainage in patients with aneurysmal subarachnoid hemorrhage for prevention of symptomatic vasospasm and late hydrocephalus.

The optimal duration of cerebrospinal fluid (CSF) drainage after acute aneurysm surgery is unclear. The association between the occurrence of symptomatic vasospasm or late hydrocephalus and the duration of CSF drainage was investigated using multiple logistic analysis in 95 consecutive patients with aneurysmal subarachnoid hemorrhage who underwent surgery within 72 hours after onset. The duration of drainage was significantly related to the occurrence of symptomatic vasospasm and late hydrocephalus. The cut-off values of the duration of drainage for preventing symptomatic vasospasm and late hydrocephalus were 11 days (adjusted odds ratio 0.347, 95% confidence interval 0.135-0.889, p = 0.0274) and 6 days (adjusted odds ratio 4.86, 95% confidence interval 1.46-16.2, p = 0.0099), respectively. Prevention of both symptomatic vasospasm and late hydrocephalus is not possible without additional procedures such as cisternal irrigation using fibrinolytic agents.

Adult↗

PubMed2005

Multiple epidermoid cysts located in the pineal and extracranial regions treated by neuroendoscopy.

A 22-year-old woman presented with a rare case of multiple epidermoid cysts located in the pineal and extracranial regions. Magnetic resonance (MR) imaging showed a lesion in the pineal region as hypointense on the T(1)-weighted image and hyperintense on the T(2)-weighted image, without enhancement. Neuroendoscopic treatment was performed under a diagnosis of pineal cyst. However, the cyst wall was too thick to perforate, although third ventriculostomy was performed. Diffusion-weighted MR imaging demonstrated the lesions in the pineal and extracranial regions as marked hyperintensity. The diagnosis was epidermoid cyst. Subsequently, neuroendoscopic treatment of the pineal epidermoid cyst was performed. Careful preoperative diagnosis of epidermoid cysts based on diffusion-weighted MR imaging is required.

Adult↗

PubMed2005

Surgical anatomy of the cervical carotid artery for carotid endarterectomy.

Carotid endarterectomy (CEA) is the main treatment for atherosclerotic plaque of the cervical internal carotid artery. The surgical anatomy of the carotid arteries was studied in the carotid triangle of 49 cadavers. The carotid bifurcation was located at the level of the lower third of C-3. The superior thyroid artery arose from the anterior wall of the external carotid artery in 70% of specimens and from the distal portion of the common carotid artery in 30%. The lingual artery arose as a separate trunk between the origins of the superior thyroid and facial arteries in 81% of specimens, with the facial artery from a common trunk in 18%, and with the superior thyroid artery in 1%. The occipital artery arose from the posterior aspect of the external carotid artery above the level of origin of the facial artery in 57% of specimens, between the origins of the facial and lingual arteries in 32%, and below the origin of the lingual artery in 11%. The origin of the occipital artery was positioned low and the distal portion of the occipital artery was crossed by the hypoglossal nerve in 20%. The ascending pharyngeal artery arose from the posterior wall of the external carotid artery above the level of origin of the lingual artery in 66% of specimens, below the origin of the lingual artery in 9%, from the proximal portion of the occipital artery in 19%, from the carotid bifurcation in 2%, and from the internal carotid artery in 2%. The branches of the external carotid artery are the key landmarks for adequate exposure and appropriate placement of cross-clamps on the carotid arteries. It is necessary to understand the surgical anatomy of the carotid arteries to carry out successful removal of plaque and minimize postoperative complications in a bloodless surgical field.

Aged↗