Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
World Neurosurg ; 2024 May 24.
Article in English | MEDLINE | ID: mdl-38797281

ABSTRACT

BACKGROUND: Schwannomas and meningiomas are the most common intradural extramedullary spinal tumors; however, differentiating between them using magnetic resonance imaging (MRI) is a frequent challenge. In this study, we aimed to investigate the use of the contrast ratio (CR) as a quantitative MRI method in the differentiation of schwannomas and meningiomas. METHODS: We analyzed the data of patients with intradural extramedullary spinal tumors who underwent surgery and were diagnosed with either schwannomas or meningiomas by histopathological analysis. Regions of interest were set for the entire spinal tumor on T2-weighted sagittal MRI. To obtain the CR values of spinal tumors (CRtumor), we used the signal intensity (SI) values of the tumor (SItumor) and spinal cord (SIcord) according to the following formula: [CRtumor = (SItumor-SIcord)/(SItumor+SIcord)]. RESULTS: The study included 50 patients (23 males and 27 females) with a mean age of 61.5 years old (11-85 years old). Histopathological analysis revealed that 33 and 17 patients were diagnosed with schwannomas and meningiomas, respectively. The mean CR values of the schwannomas and meningiomas were 0.3040 ± 0.1386 and 0.0173 ± 0.1929, respectively. The CR value of the schwannomas was statistically significantly higher than that of meningiomas (P < 0.01). The cutoff CR value obtained from the receiver operating characteristic curve was 0.143, with a specificity and sensitivity of 90.9% and 88.2%, respectively. Furthermore, the value for the area under the receiver operating characteristic curve was 0.925 (95% confidence interval: 0.852-0.998). CONCLUSIONS: The evaluation of CRs by using MRI to distinguish between schwannomas and meningiomas is a beneficial quantitative tool.

2.
Eur Spine J ; 33(5): 2116-2128, 2024 May.
Article in English | MEDLINE | ID: mdl-38436876

ABSTRACT

PURPOSE: Vertebral endplate lesions (EPLs) caused by severe disk degeneration are associated with low back pain. However, its pathophysiology remains unclear. In this study, we aimed to develop a vertebral EPL rat model mimicking severe intervertebral disk (IVD) degeneration by injecting monosodium iodoacetate (MIA) into the IVDs and evaluating it by assessing pain-related behavior, micro-computed tomography (CT) findings, and histological changes. METHODS: MIA was injected into the L4-5 and L5-6 IVDs of Sprague-Dawley rats. Their behavior was examined by measuring the total distance traveled and the total number of rearing in an open square arena. Bone alterations and volume around the vertebral endplate were assessed using micro-CT. Safranin-O staining, immunohistochemistry, and tartrate-resistant acid phosphatase (TRAP) staining were performed for histological assessment. RESULTS: The total distance and number of rearing times in the open field were significantly reduced in a time-dependent manner. Micro-CT revealed intervertebral osteophytes and irregularities in the endplates at 12 weeks. The bone volume/tissue volume (BV/TV) around the endplates significantly increased from 6 weeks onward. Safranin-O staining revealed severe degeneration of IVDs and endplate disorders in a dose- and time-dependent manner. Calcitonin gene-related peptide-positive nerve fibers significantly increased from 6 weeks onward. However, the number of osteoclasts decreased over time. CONCLUSION: Our rat EPL model showed progressive morphological vertebral endplate changes in a time- and concentration-dependent manner, similar to the degenerative changes in human IVDs. This model can be used as an animal model of severe IVD degeneration to better understand the pathophysiology of EPL.


Subject(s)
Disease Models, Animal , Intervertebral Disc Degeneration , Lumbar Vertebrae , Rats, Sprague-Dawley , Animals , Rats , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/pathology , Intervertebral Disc Degeneration/chemically induced , Intervertebral Disc Degeneration/pathology , Intervertebral Disc Degeneration/diagnostic imaging , Male , X-Ray Microtomography , Intervertebral Disc/pathology , Intervertebral Disc/diagnostic imaging , Iodoacetic Acid/toxicity
3.
Article in English | MEDLINE | ID: mdl-38504585

ABSTRACT

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: To characterize the motor evoked potential (MEP) when the epiconus or conus medullaris is compressed by a fracture of the T12 or L1 vertebra. SUMMARY OF BACKGROUND DATA: Although the characteristics of compressive cervical and thoracic myelopathy with transcranial magnetic stimulation MEP have been reported, the MEP parameters in compressive disorders of the epiconus and conus medullaris have not yet been characterized. METHODS: Twenty patients with T12 or L1 vertebral fractures who had lower extremity symptoms due to compression of the epiconus or conus medullaris were included. These patients were compared with 28 healthy controls and 32 patients with cervical spondylotic radiculopathy (CSR) without spinal cord compression. MEPs of abductor hallucis muscles were recorded using transcranial magnetic stimulation and electrical stimulation of the tibial nerve. MEP latency, central motor conduction time (CMCT), and peripheral conduction time (PCT) were evaluated. RESULTS: MEP latency, CMCT, and PCT were significantly longer in patients with fractures than in healthy controls and patients with CSR. MEP latency was most accurate for differentiating patients with fracture from healthy controls (cutoff value, 40.0 ms, sensitivity, 95.0%; specificity, 100%), and CMCT was most accurate for comparing patients with fracture and CSR (cutoff value, 15.5 ms, sensitivity, 80.0%; specificity, 93.8%). In the distinction between patients with fracture and CSR, 16 of the 20 patients with fracture exceeded the cutoff values for any of the parameters, and 12 of them exceeded the cutoff values for all parameters. There was no significant correlation between the linear distance from the most inferior end of the spinal cord to the site of compression and any of the MEP parameters. CONCLUSION: Both CMCT and PCT are often prolonged in compressive lesions of the epiconus and conus medullaris, and MEP latency and CMCT are useful in the diagnosis.

4.
Eur Spine J ; 33(3): 1061-1068, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38072862

ABSTRACT

PURPOSE: Corrective long spinal fusion is a widely accepted surgical method for patients with adult spinal deformities. However, instrumented long fusion is associated with a significant risk of complications. Therefore, we aimed to assess the success of short-segment spinal fusion, particularly for bone marrow edema (BME) adjacent to the vertebral endplate, in patients with low back pain (LBP) and spinal deformity. METHODS: A prospective study was performed at multiple hospitals wherein we monitored patients with spinal deformities and accompanying LBP. Patients aged ≥ 50 years with a minimum LBP severity score of 40 mm on the visual analog scale (VAS) were included in the study. We also included patients with lumbar BME on magnetic resonance imaging. Short spinal fusion was performed on segments with BME. Clinical evaluations of LBP on VAS and Oswestry Disability Index (ODI), and radiological parameters for sagittal vertical axis (SVA), pelvic incidence (PI), lumbar lordosis (LL) and pelvic tilt (PT) were carried out. RESULTS: Overall, 35 patients (22 men and 13 women), with a mean age of 66.7 years and a mean follow-up period of 32 months, were included in the study. The mean VAS and ODI scores were 72.4 mm and 49.0% before surgery and 25.5 mm and 29.9% at the final follow-up, respectively; these parameters significantly improved after surgery. The SVA, PI-LL, and PT scores were 70.1 mm, 20.9°, and 22.8° before surgery and 85.4 mm, 13.8°, and 22.7° at the final follow-up, respectively. The spinal alignment parameters did not change significantly after surgery. CONCLUSIONS: Short-segment spinal fusion is effective for treating LBP and spinal deformity with BME adjacent to the vertebral endplate without spinal correction.


Subject(s)
Lordosis , Low Back Pain , Spinal Fusion , Adult , Male , Humans , Female , Aged , Low Back Pain/diagnostic imaging , Low Back Pain/etiology , Low Back Pain/surgery , Spinal Fusion/methods , Prospective Studies , Bone Marrow , Treatment Outcome , Lordosis/surgery , Retrospective Studies , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/surgery
5.
Medicina (Kaunas) ; 59(9)2023 Aug 28.
Article in English | MEDLINE | ID: mdl-37763680

ABSTRACT

Background and objectives: Although chemonucleolysis with condoliase for lumbar disc herniation (LDH) has become common, few reports have described its application in the treatment of recurrent LDH. Therefore, this study aimed to evaluate the safety and efficacy of condoliase treatment in six patients with recurrent LDH and review the available literature on condoliase treatment for LDH. Materials and Methods: Six patients (four men and two women; mean age, 64.7 years) with recurrent LDH who were treated with condoliase at our hospital between 2019 and 2022 were included. The clinical records and images of the patients were retrospectively evaluated. In addition, the available English literature on condoliase treatment for LDH was retrieved and reviewed. Results: Among the six patients included in the study, three showed >50% improvement in leg pain after treatment, which is a lower efficacy rate than that in previous reports. In addition, two patients required surgery after treatment, which is a higher rate than that in previous reports. The mean intervertebral disc height significantly decreased from 8.4 mm before treatment to 6.9 mm after treatment, consistent with the results of previous studies. None of the cases showed Modic type I changes on magnetic resonance imaging. Conclusions: Although the efficacy of condoliase treatment for recurrent LDH may be lower than that for primary LDH, this treatment was found to be safe and applicable for recurrent LDH.

6.
Acta Neurochir (Wien) ; 164(6): 1493-1499, 2022 06.
Article in English | MEDLINE | ID: mdl-35124747

ABSTRACT

BACKGROUND: To determine the optimal treatment for spontaneous spinal epidural hematoma (SSEH). The aim of this study was to identify factors associated with SSEH. METHODS: In 62 patients with SSEH, several patient-related parameters were analyzed as candidate factors associated with Frankel grade before treatment or at the last follow-up. These parameters were compared between patients with and without surgery. In addition, multivariate ordinal logistic regression analysis was used to identify factors significantly associated with Frankel's grade before treatment or at the last follow-up. RESULTS: There were significant differences in age, location of the hematoma, and Frankel grade before treatment and at the last follow-up between surgical and nonsurgical cases in all patients, but there were no significant differences in any of these parameters when comparing patients with pre-treatment Frankel grade C. The location of the hematoma was significantly associated with the severity of paralysis before treatment. In surgical cases, the time from onset to surgery and the location of the hematoma was significantly associated with the prognosis. When the time from onset to surgery was evaluated using the criteria of 12, 24, and 48 h, 24 and 48 h had a significant impact on the prognosis. In the analysis of nonsurgical cases, only the vertical size of the hematoma was significantly associated with prognosis. CONCLUSION: The time from onset to surgery and the location of the hematoma were prognostic factors in surgical cases, while the vertical size of the hematoma was a prognostic factor in nonsurgical cases.


Subject(s)
Hematoma, Epidural, Spinal , Case-Control Studies , Hematoma, Epidural, Spinal/diagnostic imaging , Hematoma, Epidural, Spinal/surgery , Humans , Magnetic Resonance Imaging , Paralysis , Prognosis
7.
Eur Spine J ; 30(7): 2020-2032, 2021 07.
Article in English | MEDLINE | ID: mdl-33733329

ABSTRACT

PURPOSE: Treatment of low back pain (LBP) associated with elderly degenerative lumbar scoliosis (DLS) remains controversial. We have developed percutaneous intervertebral-vacuum polymethylmethacrylate injection (PIPI) targeting to the intervertebral vacuum as a minimally invasive surgery. The present study compared the long-term clinical outcomes of PIPI to that of nonoperative treatment. METHODS: Patients with de novo DLS, aged ≥ 65 years, who had LBP with visual analog scale (VAS) of ≥ 50 for ≥ 6 months with intervertebral vacuum on computed tomography and bone marrow edema (BME) on magnetic resonance imaging were included. The clinical outcomes were evaluated using VAS and the Oswestry Disability Index (ODI) at baseline, 1, 6, 12, 24 months, and at the final follow-up. The course of BME was also evaluated. RESULTS: One hundred and one patients underwent PIPI and 61 received nonoperative treatment. The mean follow-up duration after PIPI and nonoperative treatment was 63.7 ± 32.4 and 43.9 ± 20.9 months, respectively. VAS and ODI after PIPI were significantly improved compared to post-nonoperative treatment. BME decreased substantially in the PIPI group and it was significantly correlated with VAS and ODI improvement. Following PIPI, LBP recurred in 28 patients (35%). LBP recurrence was identified at the same level of PIPI in 10 patients, at the adjacent level of PIPI in 11 patients, and at the non-adjacent level of PIPI in seven patients. Eighteen patients underwent additional PIPIs, and both VAS and ODI were significantly improved after additional PIPIs. CONCLUSION: Bone marrow lesions of the endplate are strongly associated with the presence of LBP. PIPI can be considered as an effective, safe and repeatable treatment for LBP in elderly DLS patients.


Subject(s)
Low Back Pain , Scoliosis , Spinal Fusion , Aged , Humans , Low Back Pain/diagnostic imaging , Low Back Pain/therapy , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/surgery , Lumbosacral Region , Scoliosis/diagnostic imaging , Scoliosis/surgery , Treatment Outcome
8.
J Phys Chem A ; 121(8): 1577-1586, 2017 Mar 02.
Article in English | MEDLINE | ID: mdl-28191974

ABSTRACT

Supramolecular complexation of γ-cyclodextrin (γ-CD) with N,N'-bis(2,6-dimethylphenyl)perylene-3,4,9,10-tetracarboxylic diimide (DMP-PDI) or N,N'-bis(2,6-dioctyl)perylene-3,4,9,10-tetracarboxylic diimide (C8-PDI) dye in an aqueous solution and in a γ-CD solid film were investigated via ensemble and single-molecule fluorescence spectroscopy. These two perylene diimide derivatives possess almost the same electronic structure but have different terminal functional groups. This structural difference leads to formation of an inclusion complex of γ-CD with DMP-PDI but not with C8-PDI in aqueous solution. In a γ-CD solid film, the distributions of the wavelengths of emission maximum (λmaxem) are strikingly different between these two dyes; a much narrower and blue-shifted λmaxem distribution was observed for C8-PDI relative to DMP-PDI. This difference is attributed to the fact that the C8-PDI molecules are bound at the γ-CD/glass interface as a result of spin-coating of the sample solution, whereas the DMP-PDI molecules form 1:1 and 1:2 inclusion complexes with conformational heterogeneities in the film. In comparison to the case for C8-PDI, more frequent on-off blinking events were observed for DMP-PDI. The blinking statistics of DMP-PDI in the γ-CD film exhibit both single-exponential and nonexponential (i.e., dispersive) kinetics, revealed by robust statistical analysis. Energetic consideration with the aid of theoretical calculations suggests that the underlying photophysics most probably involves hydrogen atom transfer (HAT) between the DMP-PDI guest and γ-CD host via higher excited (n, π*) triplet states. The hypothesis of HAT in the inclusion complex reasonably explains the experimental results; however, a charge transfer hypothesis cannot explain the results. The dispersive kinetics is attributable to the effect of thermal fluctuation in the forward and backward HAT reactions.

9.
Neuro Endocrinol Lett ; 35(6): 510-7, 2014.
Article in English | MEDLINE | ID: mdl-25433845

ABSTRACT

BACKGROUND: This study investigated the relationships between psychopathy and impulsive and risky decision making, by utilizing intertemporal and probabilistic choices for both gain and loss, in addition to the Iowa gambling task. METHODS: The Psychopathic Personality Inventory-Revised - a 154-item measure that assesses psychopathic traits by self-report - was used with a 4-point response scale to assess 113 undergraduate students from three Japanese universities. Participants' performance on the Iowa Gambling Task and four behavioral neuroeconomic tasks of discounting - delayed gain, delayed loss, uncertain gain, and uncertain loss - were estimated. RESULTS: Risky decisions in probability discounting of gain and loss were associated with psychopathy. Psychopathic traits had no relationship with performance on the Iowa Gambling and were not significantly related to delay discounting. CONCLUSIONS: Psychopathy is predicted by risky decision in probability discounting of gain and loss, but not strongly associated with future myopia. Implications of the present findings for neuroeconomics and neurolaw are discussed.


Subject(s)
Antisocial Personality Disorder/diagnosis , Antisocial Personality Disorder/psychology , Gambling/psychology , Impulsive Behavior , Risk-Taking , Adolescent , Adult , Choice Behavior , Female , Games, Experimental , Humans , Male , Models, Psychological , Predictive Value of Tests , Probability , Young Adult
10.
Org Lett ; 12(12): 2856-9, 2010 Jun 18.
Article in English | MEDLINE | ID: mdl-20462201

ABSTRACT

We have established a methodology to determine the absolute configuration of alpha-chiral primary amines by derivatization to the corresponding imines with each enantiomer of 2'-methoxy-1,1'-binaphthalene-8-carbaldehyde (1). This methodology proceeds on the basis of modified Mosher's method, and sufficiently large Deltadelta(R)(S) values can be obtained to elucidate the stereochemistry of the amines.


Subject(s)
Amines/chemistry , Magnetic Resonance Spectroscopy/methods , Molecular Structure , Stereoisomerism
11.
Neuro Endocrinol Lett ; 30(2): 185-91, 2009.
Article in English | MEDLINE | ID: mdl-19675524

ABSTRACT

According to theories of cultural neuroscience, Westerners and Easterners may have distinct styles of cognition (e.g., different allocation of attention). Previous research has shown that Westerners and Easterners tend to utilize analytical and holistic cognitive styles, respectively. On the other hand, little is known regarding the cultural differences in neuroeconomic behavior. For instance, economic decisions may be affected by cultural differences in neurocomputational processing underlying attention; however, this area of neuroeconomics has been largely understudied. In the present paper, we attempt to bridge this gap by considering the links between the theory of cultural neuroscience and neuroeconomic theory of the role of attention in intertemporal choice. We predict that (i) Westerners are more impulsive and inconsistent in intertemporal choice in comparison to Easterners, and (ii) Westerners more steeply discount delayed monetary losses than Easterners. We examine these predictions by utilizing a novel temporal discounting model based on Tsallis' statistics (i.e. a q-exponential model). Our preliminary analysis of temporal discounting of gains and losses by Americans and Japanese confirmed the predictions from the cultural neuroeconomic theory. Future study directions, employing computational modeling via neural networks, are outlined and discussed.


Subject(s)
Choice Behavior , Culture , Economics , Attention , Humans , Models, Neurological , Reinforcement, Psychology , Time Factors
12.
Chem Commun (Camb) ; (4): 385-400, 2009 Jan 28.
Article in English | MEDLINE | ID: mdl-19137164

ABSTRACT

The first asymmetric total syntheses of botcinins C (18), D (19), E (20), and F (21), botcinic acid (22), botcinic acid methyl ester (23), botcineric acid (26), and 3-O-acetylbotcinic acid methyl ester () were achieved. The structures of these compounds have been unequivocally determined through their total syntheses and those of 20, 22, 23, 26, and are identified with the revised forms of the natural products formerly assumed to be 2-epibotcinolide (10), botcinolide (6), 4-O-methylbotcinolide (7), homobotcinolide (11), and 3-O-acetyl-5-O-methylbotcinolide (8), respectively. It was further proved that the proposed nine-membered ring structure of 2-epibotcinolide (10) is very unstable and the ineluctable translactonization easily occurred to form the corresponding gamma-lactone .


Subject(s)
Decanoates/chemical synthesis , Lactones/chemical synthesis , Pyrones/chemical synthesis , Decanoates/chemistry , Decanoates/isolation & purification , Lactones/chemistry , Lactones/isolation & purification , Pyrones/chemistry , Pyrones/isolation & purification
13.
Org Lett ; 10(14): 3153-6, 2008 Jul 17.
Article in English | MEDLINE | ID: mdl-18549237

ABSTRACT

Stereoselective total synthesis of botcinins C, D, and F is effectively carried out through asymmetric aldol reactions, 6-endo ring closure, and SmI2-mediated 3,4-trans or -cis stereoselective intramolecular Reformatsky reaction. Rapid esterification of the main skeleton of botcinins with the chiral side chain using MNBA and DMAP produced botcinin D, an antifungal chemical against a pathogen of rice blast disease.


Subject(s)
Antifungal Agents/chemical synthesis , Magnaporthe/drug effects , Pyrones/chemical synthesis , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Botrytis/chemistry , Molecular Structure , Plant Diseases/microbiology , Pyrones/chemistry , Pyrones/pharmacology , Stereoisomerism
14.
Chem Asian J ; 3(2): 462-72, 2008 Feb 01.
Article in English | MEDLINE | ID: mdl-18203212

ABSTRACT

We have developed effective methods for the total synthesis of 2-hydroxytetracosanolide and 2-hydroxy-24-oxooctacosanolide, the defensive salivary secretions of termites. The former natural product isolated from Armitermes neotenicus, a species of termite that inhabits Guyana, contains a 25-membered lactone backbone, and the latter, extracted from Pseudacanthoterme springer, an African termite, includes a 29-membered lactone moiety. The key cyclization to produce the 25- or 29-membered lactone core is performed by using 2-methyl-6-nitrobenzoic anhydride (MNBA) with a stoichiometric amount of 4-(dimethylamino)pyridine (DMAP) or a catalytic amount of 4-(dimethylamino)pyridine N-oxide (DMAPO).


Subject(s)
Macrolides/chemical synthesis , Benzoates/chemistry , Catalysis , Copper/chemistry , Macrolides/chemistry , Molecular Structure
15.
Nat Protoc ; 2(10): 2312-7, 2007.
Article in English | MEDLINE | ID: mdl-17947971

ABSTRACT

This protocol describes a procedure for the synthesis of a 29-membered macrolactone. The facile mixed-anhydride method is very effective for the preparation of carboxylic esters and lactones using substituted benzoic anhydrides by the promotion of Lewis acid or basic catalysts under mild reaction conditions. Owing to the reaction rapidly proceeding to produce the monomeric compounds with high chemoselectivity, the protocol is quite powerful for the synthesis of not only the giant-sized lactones but also the highly strained cyclic compounds such as medium-sized lactones. The remarkable efficiency of the lactonizations promoted by the substituted benzoic anhydrides has been already shown in the synthesis of many natural complex molecules. It takes approximately 19 h to complete the protocol: 0.5 h to set up the reaction, 13.5 h for the reaction and 5 h for isolation and purification.


Subject(s)
Benzoates/chemistry , Lactones/chemical synthesis , Chemistry, Organic/methods , Lactones/chemistry
17.
Org Lett ; 8(23): 5279-82, 2006 Nov 09.
Article in English | MEDLINE | ID: mdl-17078697

ABSTRACT

[Structure: see text] The total synthesis of pseudo 2-epibotcinolide (1b) through several featured synthetic approaches has been attained. First, the chiral linear precursors of the nine-membered ring compound is stereoselectively constructed by the asymmetric aldol reaction for producing beta-hydroxy ester units. Second, the key cyclization reaction to form the nine-membered lactone moiety is efficiently achieved by the extremely facile and powerful mixed-anhydride method promoted by 2-methyl-6-nitrobenzoic anhydride (MNBA) with basic promoters.


Subject(s)
Decanoates/chemical synthesis , Lactones/chemical synthesis , Pyrones/chemical synthesis , Botrytis/metabolism , Cyclization , Decanoates/metabolism , Lactones/metabolism , Molecular Structure , Pyrones/metabolism
18.
Neuroimage ; 32(2): 913-20, 2006 Aug 15.
Article in English | MEDLINE | ID: mdl-16682235

ABSTRACT

One of the most powerful ways of succeeding in complex social interactions is to read the minds of companions and stay a step ahead of them. In order to assess neural responses to reciprocal mind reading in socially strained human relationships, we used a 3-T scanner to perform an event-related functional magnetic resonance imaging study in 16 healthy subjects who participated in the game of Chicken. Statistical parametric mapping showed that the counterpart effect (human minus computer) exclusively activated the medial frontal area corresponding to the anterior paracingulate cortex (PCC) and the supramarginal gyrus neighboring the posterior superior temporal sulcus (STS). Furthermore, when we analyzed the data to evaluate whether the subjects made risky/aggressive or safe/reconciliatory choices, the posterior STS showed that the counterpart had a reliable effect regardless of risky or safe decisions. In contrast, a significant opponent x selection interaction was revealed in the anterior PCC. Based on our findings, it could be inferred that the posterior STS and the anterior PCC play differential roles in mentalizing; the former serves as a general mechanism for mentalizing, while the latter is exclusively involved in socially risky decisions.


Subject(s)
Attention/physiology , Cerebral Cortex/physiology , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Interpersonal Relations , Magnetic Resonance Imaging , Personal Construct Theory , Social Behavior , Adult , Aggression/physiology , Decision Making , Frontal Lobe/physiology , Game Theory , Humans , Male , Nonverbal Communication , Prefrontal Cortex/physiology , Risk-Taking , Temporal Lobe/physiology , Video Games
19.
Neuroimage ; 24(1): 253-9, 2005 Jan 01.
Article in English | MEDLINE | ID: mdl-15588617

ABSTRACT

Risk anticipation is an important cognitive/emotional component of decision making. The Iowa Gambling Task [Bechara, A., Damasio, A.R., Damasio, H., Anderson, S.W., 1994. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition 50, 7-15], which is the most widely used "risk-anticipation task" in clinical studies, has been demonstrated to be sensitive to lesions involving the ventromedial prefrontal cortex or amygdala. However, the critical neural circuitry involved in this complex task has not yet been fully clarified even in healthy subjects. Using a 3-T scanner, we performed an event-related functional magnetic resonance imaging study in 14 healthy subjects performing the task. The statistical parametric mapping showed that the risk anticipation component (risky decisions minus safe decisions) exclusively activated the medial frontal gyrus. Furthermore, we found a significant interindividual correlation between the task performance and the magnitude of brain activity during risky decisions. These results indicate that the Iowa Gambling Task does recruit the neural circuitry that is critical in decision making under uncertainty, particularly when subjects perceive the risk of their decision.


Subject(s)
Decision Making/physiology , Frontal Lobe/physiology , Gambling/psychology , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Nerve Net/physiology , Prefrontal Cortex/physiology , Adult , Arousal/physiology , Artifacts , Attention/physiology , Brain Mapping , Emotions/physiology , Evoked Potentials/physiology , Female , Games, Experimental , Humans , Male , Risk-Taking , Statistics as Topic
20.
J Org Chem ; 68(20): 7800-5, 2003 Oct 03.
Article in English | MEDLINE | ID: mdl-14510558

ABSTRACT

Various 1,1-difluoro-1-alkenes such as monosubstituted 1,1-difluoro-1-alkenes, 2-bromo-1,1-difluoro-1-alkenes, and 3,3-difluoroallylic alcohols are synthesized in two simple steps from 1-trifluoromethylvinylsilane: (i) its SN2' reaction with nucleophiles to construct 2,2-difluorovinylsilanes and (ii) the subsequent substitution of electrophiles for the vinylic silyl group. The combination of these two processes allows a one-pot synthesis of the functionalized 1,1-difluoro-1-alkenes starting from 1-trifluoromethylvinylsilane, which functions as a CF2=C(-)-CH2+ synthon.

SELECTION OF CITATIONS
SEARCH DETAIL
...