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Murayama Y, Mohamed A, Takao H, Ishibashi T, Yuki I. E-005 Accuracy of software for intracranial aneurysm geometry quantification: Abstract E-005 Figure 1. J Neurointerv Surg 2012. [DOI: 10.1136/neurintsurg-2012-010455c.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Farnoush A, Qian Y, Takao H, Murayama Y, Avolio A. Effect of saccular aneurysm and parent artery morphology on hemodynamics of cerebral bifurcation aneurysms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2012:6677-6680. [PMID: 23367461 DOI: 10.1109/embc.2012.6347526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Morphological descriptors of aneurysms have been used to assess aneurysm rupture. This study investigated the relation between the morphological parameters and the flow related parameter of energy loss (EL). Four size indices and one shape index were assessed in idealized middle cerebral artery models with various aneurysm morphologies. Four patient-specific aneurysms (2 ruptured, 2 unruptured) were virtually manipulated by removing the aneurysms from their parent arteries and merging them with the idealized bifurcation models. EL was calculated from the energy difference between inflow and outflow. The results indicate that among size indices, EL is mostly dependent on bottleneck factor and less dependent on the aspect ratio. Results also showed that there is a direct relationship between nonsphericity index (NSI) and EL in manipulated models. No specific correlation was found between EL and NSI in patient-specific models.
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Yuki I, Kan I, Vinters HV, Kim RH, Golshan A, Vinuela FA, Sayre JW, Murayama Y, Vinuela F. The impact of thromboemboli histology on the performance of a mechanical thrombectomy device. AJNR Am J Neuroradiol 2011; 33:643-8. [PMID: 22207297 DOI: 10.3174/ajnr.a2842] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Recently we published a novel method of thrombus preparation for use in a swine model for evaluation of thrombectomy designs. The clot (fibrin rich clot) is characterized by its similarity in histologic characteristics to the thromboemboli recovered from stroke patients. The purpose of this latest study was to evaluate if the performance of a mechanical thrombectomy device was affected by the histologic characteristics of thromboembolus. Erythrocyte rich clot, which was created using exogenous thrombin, and the novel experimental clot with abundance of fibrin/cellular component were used for comparison. The Merci clot retriever was used for the evaluation and the angiographic outcomes were analyzed. MATERIALS AND METHODS Two histologically different types of experimental clot, a conventionally used thrombin-induced clot (erythrocyte-rich clot) and a novel experimental clot that is similar in histologic characteristics to the thromboemboli recovered from patients with stroke (fibrin-rich clot), were prepared. Eight extracranial arteries in swine were occluded with erythrocyte-rich clot (group A), and 8 were occluded with fibrin-rich clot (group B), and MT by using the Merci clot retriever device was performed. Angiographic results in each group were evaluated. RESULTS A total of 48 attempts at MT were made. The average number of attempts to achieve TIMI grade II or III recanalization was 2.75 times in group A and 4.5 times in group B (P < .001), respectively. The mean time to achieve recanalization was 15.5 minutes in group A and 81.5 minutes in group B (P < .01). Every vessel in group A showed recanalization (100%), whereas only 3 of 8 samples (37.5%) achieved recanalization in group B. CONCLUSIONS In this model, arteries occluded by fibrin-rich clot demonstrated a significantly lower recanalization rate, lower final TIMI score, and a longer mean recanalization time than did arteries occluded by erythrocyte-rich clot. The angiographic outcome of MT by using the Merci clot retriever system was influenced by the histologic characteristics of the occluding thromboembolus.
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Ozaki M, Murayama Y, Ebara M, Takao H, Abe T. Delayed hydrocephalus after embolization of unruptured aneurysms using bare platinum coils: report of 2 cases. AJNR Am J Neuroradiol 2011; 32:E188-90. [PMID: 21233231 DOI: 10.3174/ajnr.a2317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Postembolization hydrocephalus with bare platinum coils has not been reported, to our knowledge. We report 2 cases of unusual delayed hydrocephalus after treatment of unruptured intracranial aneurysms with bare platinum coils.
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Qian Y, Takao H, Umezu M, Murayama Y. Risk analysis of unruptured aneurysms using computational fluid dynamics technology: preliminary results. AJNR Am J Neuroradiol 2011; 32:1948-55. [PMID: 21903914 DOI: 10.3174/ajnr.a2655] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The decision as to the treatment of incidental IAs is complex. There are no certain quantitative methods that can be used to evaluate the risk of rupture in IAs. In recent years, CFD technology has been recognized as a potential risk-analysis tool. The aim of this article was to propose a hemodynamic parameter, EL, to determine the effects of stable unruptured aneurysms and of those that ruptured during the subsequent observation period. MATERIALS AND METHODS Four incidentally found ICA-PcomA aneurysms ruptured during the period of observation (ruptured-IAs). Another 26 unruptured aneurysms (stable-IAs) with similar location, size, and morphology were compared for the differences in hemodynamic factors, such as EL and WSS. RESULTS The EL calculated at the ruptured-IAs was nearly 5 times higher on average than that at the stable-IAs (ruptured, 0.00374 ± 0.0011; stable, 0.000745 ± 0.0001 mW/mm(3), P < .001). However, there was no difference between the ruptured and stable groups according to the results of time-averaged WSS (P = .8) for ruptured- and stable-IAs. According to flow visualization, though the mean average inflow speed of ruptured-IAs was 2 times higher than that of the stable-IAs, the flow inside ruptured-IAs appeared to undergo longer resident tracks, with stronger impact on the aneurysm wall. On the contrary, the flow inside stable-IAs passed smoothly through the aneurysms. CONCLUSIONS These preliminary results indicated that EL may be a useful parameter for the quantitative estimation of the risks of rupture for IAs.
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Okada H, Iwamaru Y, Imamura M, Masujin K, Matsuura Y, Murayama Y, Mohri S, Yokoyama T. Detection of disease-associated prion protein in the posterior portion of the small intestine involving the continuous Peyer's patch in cattle orally infected with bovine spongiform encephalopathy agent. Transbound Emerg Dis 2011; 58:333-43. [PMID: 21320296 DOI: 10.1111/j.1865-1682.2011.01208.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Twenty-eight calves were exposed to 5 g of homogenized brainstems confirmed as bovine spongiform encephalopathy (BSE) agents. Two to five animals were sequentially killed for post-mortem analyses 20 months post-inoculation (MPI) at intervals of 6 or 12 months. Samples from animals challenged orally with BSE agents were examined by Western blot and immunohistochemical analyses. Immunolabelled, disease-associated prion protein (PrPsc) was detected in a small portion of follicles in the continuous Peyer's patch from the posterior portion of the small intestine involving the entire ileum and the posterior jejunum but not in the discrete Peyer's patches in the remaining jejunum in preclinical animals at 20, 36, and 48 MPI. The PrPsc-positive cells corresponded to tingible body macrophages on double immunofluorescence labelling. In addition, PrPsc accumulated in 7 of 14 animals in the central nervous system (CNS) after 34 MPI, and five of them developed clinical signs and were killed at 34, 46, 58, and 66 MPI. Two preclinical animals killed at 36 and 48 MPI presented the earliest detectable and smallest deposition of immunolabelled PrPsc in the dorsal motor nucleus of the vagus nerve, the spinal trigeminal nucleus of the medulla oblongata at the obex region, and/or the intermediolateral nucleus of the 13th thoracic segment of the spinal cord. Based on serial killing, no PrPsc was detectable in the CNS, including the medulla oblongata at the obex level, before 30 MPI, by Western blot and immunohistochemical analyses. These results are important for understanding the pathogenesis of BSE.
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Takao H, Murayama Y, Qian Y, Mohamed A, Matsuda W, Umezu M, Abe T. O-018 A new hemodynamic parameter: energy loss to anticipate aneurysm rupture. J Neurointerv Surg 2010. [DOI: 10.1136/jnis.2010.003244.18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Kan I, Yuki I, Murayama Y, Viñuela FA, Kim RH, Vinters HV, Viñuela F. A novel method of thrombus preparation for use in a swine model for evaluation of thrombectomy devices. AJNR Am J Neuroradiol 2010; 31:1741-3. [PMID: 20093313 DOI: 10.3174/ajnr.a1991] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report the development of a novel technique of thrombus preparation for use in a swine model for evaluation of thrombectomy devices. The experimental thrombus prepared using plain sedimentation showed mechanical stability due to its solid fibrin-rich component. The thrombus also showed histologic similarity to the typical thromboemboli recovered from patients with stroke in the course of therapeutic thrombectomy. This new technique may be beneficial for preclinical evaluation of thrombectomy devices.
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Kan I, Yuki I, Murayama Y, Vinuela F, Kim R, Zhang B, Wu B, Vinters H, Vinuela F. E-019 Novel bioactive coil with modified PGLA. J Neurointerv Surg 2010. [DOI: 10.1136/jnis.2010.003251.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Murayama Y, Ishibashi T, Ebara M, Ikeuchi S, Takao H, Arakawa H, Kato M, Kobayashi N, Abe T. E-052 Robotic digital subtraction angiography systems within the hybrid operating room. J Neurointerv Surg 2010. [DOI: 10.1136/jnis.2010.003251.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Eschenko O, Canals S, Simanova I, Beyerlein M, Murayama Y, Logothetis N. Mapping of functional brain activity in freely behaving rats during voluntary running using manganese-enhanced MRI: Implication for longitudinal studies. Neuroimage 2010; 49:2544-55. [DOI: 10.1016/j.neuroimage.2009.10.079] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 10/28/2009] [Accepted: 10/29/2009] [Indexed: 10/20/2022] Open
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Lindahl OA, Constantinou CE, Eklund A, Murayama Y, Hallberg P, Omata S. Tactile resonance sensors in medicine. J Med Eng Technol 2009; 33:263-73. [PMID: 19384701 DOI: 10.1080/03091900802491188] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Tactile sensors in general are used for measuring the physical parameters associated with contact between sensor and object. Tactile resonance sensors in particular are based on the principle of measuring the frequency shift, Deltaf, defined as the difference between a freely vibrating sensor resonance frequency and the resonance frequency measured when the sensor makes contact to an object. Deltaf is therefore related to the acoustic impedance of the object and can be used to characterize its material properties. In medicine, tactile resonance sensor systems have been developed for the detection of cancer, human ovum fertility, eye pressure and oedema. In 1992 a Japanese research group published a paper presenting a unique phase shift circuit to facilitate resonance measurements. In this review we summarize the current state-of-the-art of tactile resonance sensors in medicine based on the phase shift circuit and discuss the relevance of the measured parameters for clinical diagnosis. Future trends and applications enabled by this technology are also predicted.
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Takao H, Murayama Y, Ishibashi T, Ebara M, Arakawa H, Irie K, Abe T. 003 Development of new measurement software for cerebral aneurysms. J Neurointerv Surg 2009. [DOI: 10.1136/jnis.2009.000869c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Drob DP, Emmert JT, Crowley G, Picone JM, Shepherd GG, Skinner W, Hays P, Niciejewski RJ, Larsen M, She CY, Meriwether JW, Hernandez G, Jarvis MJ, Sipler DP, Tepley CA, O'Brien MS, Bowman JR, Wu Q, Murayama Y, Kawamura S, Reid IM, Vincent RA. An empirical model of the Earth's horizontal wind fields: HWM07. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013668] [Citation(s) in RCA: 392] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hyogo T, Taki W, Negoro M, Takahashi A, Edura M, Hyodo A, Kobayashi S, Komiyama M, Kuwayama N, Matsumaru Y, Miyachi S, Murao K, Murayama Y, Nakahara I, Nemoto S, Sakai N, Satoh K, Sonobe M, Sugiu K, Terada T, Yoshimura S, Abe T, Itoh Y, Kiyosue H, Nagashima H, Nakamura M, Matsushima S. Japanese society of neuro-endovascular treatment specialist qualification system. Six years' experience and introduction of an animal model examination. Interv Neuroradiol 2008; 14:235-40. [PMID: 20557719 DOI: 10.1177/159101990801400302] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Accepted: 07/01/2008] [Indexed: 11/15/2022] Open
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Pancheva D, Mukhtarov P, Mitchell NJ, Merzlyakov E, Smith AK, Andonov B, Singer W, Hocking W, Meek C, Manson A, Murayama Y. Planetary waves in coupling the stratosphere and mesosphere during the major stratospheric warming in 2003/2004. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009011] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Miwa H, Yokoyama T, Hori K, Sakagami T, Oshima T, Tomita T, Fujiwara Y, Saita H, Itou T, Ogawa H, Nakamura Y, Kishi K, Murayama Y, Hayashi E, Kobayashi K, Tano N, Matsushita K, Kawamoto H, Sawada Y, Ohkawa A, Arai E, Nagao K, Hamamoto N, Sugiyasu Y, Sugimoto K, Hara H, Tanimura M, Honda Y, Isozaki K, Noda S, Kubota S, Himeno S. Interobserver agreement in endoscopic evaluation of reflux esophagitis using a modified Los Angeles classification incorporating grades N and M: a validation study in a cohort of Japanese endoscopists. Dis Esophagus 2008; 21:355-63. [PMID: 18477259 DOI: 10.1111/j.1442-2050.2007.00788.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Los Angeles classification system is the most widely employed criteria associated with the greatest interobserver agreement among endoscopists. In Japan, the Los Angeles classification system has been modified (modified LA system) to include minimal changes as a distinct grade of reflux esophagitis, rather than as auxiliary findings. This adds a further grading M defined as minimal changes to the mucosa, such as erythema and/or whitish turbidity. The modified LA system has come to be used widely in Japan. However, there have been few reports to date that have evaluated the interobserver agreement in diagnosis when using the modified LA classification system incorporating these minimal changes as an additional grade. A total of 100 endoscopists from university hospitals and community hospitals, as well as private practices in the Osaka-Kobe area participated in the study. A total of 30 video clips of 30-40 seconds duration, mostly showing the esophagocardiac junction, were created and shown to 100 endoscopists using a video projector. The participating endoscopists completed a questionnaire regarding their clinical experience and rated the reflux esophagitis as shown in the video clips using the modified LA classification system. Agreement was assessed employing kappa (kappa) statistics for multiple raters. The kappa-value for all 91 endoscopists was 0.094, with a standard error of 0.002, indicating poor interobserver agreement. The endoscopists showed the best agreement on diagnosing grade A esophagitis (0.167), and the poorest agreement when diagnosing grade M esophagitis (0.033). The kappa-values for the diagnoses of grades N, M, and A esophagitis on identical video pairs were 0.275-0.315, with a standard error of 0.083-0.091, indicating fair intraobserver reproducibility among the endoscopists. The study results consistently indicate poor agreement regarding diagnoses as well as fair reproducibility of these diagnoses by endoscopists using the modified LA classification system, regardless of age, type of practice, past endoscopic experience, or current workload. However, grade M reflux esophagitis may not necessarily be irrelevant, as it may suggest an early form of reflux disease or an entirely new form of reflux esophagitis. Further research is required to elucidate the pathophysiological basis of minimal change esophagitis.
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Canals S, Beyerlein M, Keller AL, Murayama Y, Logothetis NK. Magnetic resonance imaging of cortical connectivity in vivo. Neuroimage 2008; 40:458-472. [PMID: 18222710 DOI: 10.1016/j.neuroimage.2007.12.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/22/2007] [Accepted: 12/03/2007] [Indexed: 11/26/2022] Open
Abstract
Magnetic resonance imaging of neuronal connectivity in vivo opens up the possibility of performing longitudinal investigations on neuronal networks. This is one main reason for the attention that paramagnetic ion manganese (Mn2+) has attracted as a potential anterograde neuronal tracer for MRI experiments. However, the correct and possibly repeated use of this tracer--or of any tracer for that matter, including heavy metals--requires the development of an administration strategy that minimizes its toxic effects. Here we first investigated the conditions that maximize the tracing efficiency of Mn2+ and preserve viability and tissue architectonics in combined MRI and histology experiments in rats. We demonstrate that most common protocols for neuronal tract tracing using Mn2+ result in large neuronal and glial lesions. The toxicity of manganese is distinct during intracortical injections and blocks the transfer of the tracer. After optimizing the technique, we could show that extensive cortical connectivity maps can be generated, with no sign of neuronal damage. Importantly, preservation of tissue viability improves the efficiency of Mn2+ in tracing neuronal connections. We have successfully used this technique to trace corticofugal somatosensory and motor pathways in individual animals and describe a connectivity index (CnI) based on Mn2+ transport that quantitatively reveals cortical heterogeneities in interhemispheric communication. Finally, we have significantly improved the resolution of the technique by continuously infusing very low concentrations of Mn2+ into the target area using osmotic pumps coupled to chronically implanted brain cannulae. The specific, nontoxic and quantitative nature of the neuronal tracings described here indicates the value of this tracer for chronic studies of development and plasticity as well as for studies of brain pathology.
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Yoshioka M, Miwa T, Horii H, Takata M, Yokoyama T, Nishizawa K, Watanabe M, Shinagawa M, Murayama Y. Characterization of a proteolytic enzyme derived from a Bacillus strain that effectively degrades prion protein. J Appl Microbiol 2007; 102:509-15. [PMID: 17241357 DOI: 10.1111/j.1365-2672.2006.03080.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The purpose of this paper was to screen candidate bacterial strains for the production of proteases suitable for application to the degradation of pathogenic forms of prion protein (PrP(Sc)). This paper describes the biochemical characteristics and proteolytic activity of the isolated protease. METHODS AND RESULTS After screening more than 200 bacterial proteases for keratinolytic activity, we identified a Bacillus stain that produced a protease exhibiting high-degradation activity against a scrapie PrP(Sc). Sequence analysis indicated that this serine-protease belonged to the Subtilisin family and had optimum pH and temperature ranges of 9-10 and 60-70 degrees C. Western blotting analysis revealed that the protease was also capable of decomposing bovine spongiform encephalopathy-infected brain homogenate. In addition, the protease was demonstrated to degrade dried PrP(Sc) that had become firmly attached to a plastic surface considerably more effectively than proteinase K or PWD-1, a previously reported keratinase. CONCLUSIONS These results indicate that the isolated protease exhibited higher activity for PrP(Sc) degradation compared with other proteases examined. SIGNIFICANCE AND IMPACT OF THE STUDY This protease could be used under moderate conditions for the decontamination of precision instruments that are susceptible to PrP(Sc) contamination.
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Inui H, Mizuno J, Nakamura H, Akaishi K, Murayama Y, Omata S. Reliable ovum evaluation system by engineering technology, micro tactile sensor (MTS) system for elective single embryo transfer (ESET) on human ART. Fertil Steril 2007. [DOI: 10.1016/j.fertnstert.2007.07.330] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Arakawa H, Murayama Y, Davis CR, Howard DL, Baumgardner WL, Marks MP, Do HM. Endovascular embolization of the swine rete mirabile with Eudragit-E 100 polymer. AJNR Am J Neuroradiol 2007; 28:1191-6. [PMID: 17569986 PMCID: PMC8134130 DOI: 10.3174/ajnr.a0536] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Both adhesive and nonabrasive embolic agents are available for arteriovenous malformation (AVM) embolization. The purpose of this study was to evaluate a novel ethanol-based nonadhesive liquid embolic material in a swine AVM model. MATERIALS AND METHODS Eudragit (copolymer of methyl and butyl methacrylate and dimethylaminoethyl methacrylate) was dissolved in 50% ethanol and 50% iopamidol. Eudragit was injected into 9 retia mirabilia (RMs). Ethanol and iopamidol mixture were injected into 4 RMs for comparison. Three RMs embolized with Eudragit mixture were evaluated both angiographically and histopathologically acutely (3-24 hours) and at 30 days and 90 days after embolization. RESULTS No procedural complications from Eudragrit embolization were noted, including retention or adhesion of the microcatheter. Various degrees of inflammation were observed in the acute and 30-day specimens. Two RMs showed partial recanalization on both histopathology and follow-up angiography in the 30-day group. Arterial fibrosis and calcification were observed in the 30- and 90-day specimens. The internal elastic lamina was disrupted in the 30- and 90-day specimens, but there was no evidence of Eudragit extravasation or hemorrhage. Endothelial damage was seen in all specimens and was particularly severe in the 30- and 90-day specimens. CONCLUSION Eudragit polymer induced inflammation in thrombosis similar to n-butyl 2-cyanoacrylate, but without the disadvantages of perivascular hemorrhage and extravasation of embolization material. Although recanalization of some embolized RMs was noted, further investigation into Eudragit as a potentially useful embolic material for brain AVMs is warranted.
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Shohji T, Ishibashi T, Murayama Y, Saguchi T, Ebara M, Irie K, Takao H, Abe T. Radiation Exposure during Cerebral Artery Aneurysm Coil Embolization: the Current Situation and Measures to Prevent Radiation Injury. Interv Neuroradiol 2007; 13 Suppl 1:73-83. [PMID: 20566081 PMCID: PMC3345352 DOI: 10.1177/15910199070130s110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Accepted: 01/15/2007] [Indexed: 11/15/2022] Open
Abstract
SUMMARY Coil embolization is the treatment of choice for cerebral artery aneurysms at our institution. The duration of a fluoroscopic study and frequency of radiation exposure are varied, and the safety measures against radiation injury have not yet been established. Guidelines about radiation injury prevention with IVR have been published. However, there is not yet a detailed report for the head region. We also report our measures to try to reduce the amount of radiation exposure during the embolization procedure in our institution.
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Itoi F, Himaki T, Kubota C, Hirose J, Miyamura M, Hamano S, Murayama Y, Omata S, Yoshida M. 181 DIFFERENCES EXIST IN ZONA PELLUCIDA HARDNESS BETWEEN IN VIVO- AND IN VITRO-GENERATED BOVINE EMBRYOS. Reprod Fertil Dev 2007. [DOI: 10.1071/rdv19n1ab181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The zona pellucida (ZP) of mammalian ova plays an important role during maturation, fertilization, and early embryonic development. The hardness of ZP of mammalian ova has been mainly evaluated by a biochemical method, such as a difference in ova dissolution speed with an enzyme or an acid reagent treatment. However, the physical hardness of ZP in bovine embryos is largely unknown. Recently, we developed a system measuring the physical hardness of ZP of mammalian ova with a micro bio-sensor (MBS). The objective of this study was to examine the physical ZP hardness of in vivo- and in vitro-derived bovine embryos using an MBS. In the measurement system, the thin glass needle was connected at the tip of a piezo-electric ceramic tactile sensor, and the sample was pushed into a sensor at fixed speed under the computer-controlled micromanipulation system. The change in frequency at the time of displacement of the sample into the sensor was recorded using the computer program. Measurement of gelatin samples of known concentration (4 to 8%) was used to determine the basic characteristic of a sensor and to make a standard curve. In vivo-generated embryos were recovered from 6 superovulated Japanese Black cows with multiple injection of FSH. On Day 7 after insemination, morulae (M), early blastocysts (EB), and blastocysts (BL) were recovered by nonsurgical flushing of uterine horns. In vitro-generated embryos were produced as described earlier (Yoshida et al. 1998 J. Vet. Med. Sci. 60, 549–554). The M, EB, and BL at Days 5 to 7 of post-insemination in vitro were used for measurement of ZP hardness. When a sensor made contact with a harder gelatin sample, the change in frequency was large; the change in frequency has the characteristic of being small for a softer gelatin sample. By comparison with a standard curve, ZP hardness converted into gelatin concentration for each stage of bovine embryos generated in vivo was 3.95% (M: n = 9), 4.14% (EB: n = 32), and 3.92% (BL: n = 14), respectively. On the other hand, ZP hardness of bovine embryos generated in vitro was 3.42% (M: n = 56), 3.33% (EB: n = 36), and 3.25% (BL: n = 23), respectively. There was a significant difference (P < 0.01) in the hardness of ZP between in vivo- and in vitro-generated bovine embryos.
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Sutani A, Nagai Y, Udagawa K, Uchida Y, Koyama N, Murayama Y, Tanaka T, Miyazawa H, Nagata M, Kanazawa M, Hagiwara K, Kobayashi K. Gefitinib for non-small-cell lung cancer patients with epidermal growth factor receptor gene mutations screened by peptide nucleic acid-locked nucleic acid PCR clamp. Br J Cancer 2006; 95:1483-9. [PMID: 17106442 PMCID: PMC2360739 DOI: 10.1038/sj.bjc.6603466] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
This study was prospectively designed to evaluate a phase II study of gefitinib for non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations. Clinical samples were tested for EGFR mutations by peptide nucleic acid-locked nucleic acid PCR clamp, and patients having EGFR mutations were given gefitinib 250 mg daily as the second treatment after chemotherapy. Poor PS patients omitted chemotherapy. Of 107 consecutive patients enrolled, samples from 100 patients were informative, and EGFR mutations were observed in 38 patients. Gefitinib was given to 27 patients with EGFR mutations, and the response rate was 78% (one complete response and 20 partial responses; 95% confidence interval: 58–93%). Median time to progression and median survival time (MST) from gefitinib treatment were 9.4 and 15.4 months, respectively. Grade 3 hepatic toxicity and skin toxicity were observed in one patient each. There were significant differences between EGFR mutations and wild-type patients in response rates (78 vs 14%, P=0.0017), and MST (15.4 vs 11.1 months, P=0.0135). A Cox proportional hazards model indicated that negative EGFR mutation was a secondary prognostic factor (hazards ratio: 2.259, P=0.036). This research showed the need for screening for EGFR mutations in NSCLC patients.
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Ishii A, Viñuela F, Murayama Y, Yuki I, Nien YL, Yeh DT, Vinters HV. Swine model of carotid artery atherosclerosis: experimental induction by surgical partial ligation and dietary hypercholesterolemia. AJNR Am J Neuroradiol 2006; 27:1893-9. [PMID: 17032861 PMCID: PMC7977876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
INTRODUCTION Limited availability of a large animal model of carotid atherosclerosis has limited preclinical evaluation of endovascular therapeutic devices. The present study is aimed at developing such animal models with a novel approach, emphasizing the role of hemodynamics. METHODS Using 18 carotid arteries from 9 miniswine, surgical partial ligation (approximately 80% stenosis) was carried out in untreated (group I; n = 6) and balloon-injured arteries (group II; n = 9). Three arteries were subjected to sham-operation for control (group III; n = 3). All animals were fed with a high-fat diet until sacrifice. Angiograms and histologic sections of the vessels were analyzed to evaluate both models. RESULTS Atherosclerotic changes were confirmed in 6 of 6 in group I and 6 of 9 arteries in group II, whereas all in group III remained intact. Three arteries in group II resulted in thrombotic occlusion. Advanced plaques with intraplaque hemorrhage and/or calcification were seen in 4 of 6 arteries in group I but none in group II. The cross-sectional area stenosis and atherosclerotic stage for plaques in group I were both significantly higher than that in groups II and III. CONCLUSION In this series, surgical partial ligation with concomitant dietary hyperlipidemia is an appropriate experimental technique to develop advanced atherosclerotic plaques with minimal technical complications. This model showed no evidence of such benefits when applied in balloon-injured arteries.
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