Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section, 1991
Pattern visual evoked potentials (VEPs) to transient and steady-state stimulation were recorded i... more Pattern visual evoked potentials (VEPs) to transient and steady-state stimulation were recorded in 10 normal subjects at 4 levels of luminance (180, 57, 22 and 11 cd/m2). VEPs were also recorded in 5 patients with optic neuropathy at a fixed luminance (180 cd/m2). The relationship between P100 latency of transient VEPs (T-VEPs) and the phase of steady-state VEPs (S-VEPs) was analyzed. As luminance decreased in normal subjects, P100 latency was prolonged and the phase lag increased. A significant linear relationship between the P100 latency and phase was found. Patients showed both the prolonged P100 latency and the delayed phase. The simple linear regression line of the phase-P100 latency function of normal subjects closely matched the patients' values. These results suggest that changes in the phase may be equivalent to changes in the P100 latency. S-VEPs, therefore, may be clinically useful in assessing visual function.
2009 ICME International Conference on Complex Medical Engineering, 2009
Dominant rhythm in electroencephalographic (EEG) records is seen at the posterior to occipital re... more Dominant rhythm in electroencephalographic (EEG) records is seen at the posterior to occipital region as a primary component of background activity during waking state with closed eyes and is decreased or disappeared by the exogenous factors such as visual stimuli to eyes and so on. Visual evoked potential (VEP) can also be seen in EEG at the posterior to occipital regions during photic stimulation (PS). Frequency components of VEP are depended upon the frequency of stimuli and that of dominant rhythm in case of healthy adult is around 10 Hz. Therefore, components of VEP and dominant rhythm are almost overlapped when the frequency of photo stimuli is near around 10 Hz. VEP component can be extracted from the background activity by using the averaging method, but the accurate estimation of dominant rhythm component in such condition has difficulties due to the overlapping of both components in frequency domain. Some of the authors have proposed the EEG model with Markov process amplitude (MPA EEG model) in the past. The MPA EEG model has possibilities to separate the components that construct the original EEG into each one in the frequency domain. In this study, component decomposition of VEP and dominant rhythm of recorded EEG was done by using the MPA EEG model. EEGs with PS were recorded from three healthy young adults. Five seconds continuous EEG time series with PS and without PS were selected from the original data, and were transferred to the periodogram information by the FFT method. Then, the model parameters were calculated. The initial values of model parameters were determined from the periodogram of raw EEG during PS, and were optimized by Fletcher-Powell method. In the original data under PS with 10 Hz, VEP component and dominant rhythm component were overlapped each other. Proposed method decomposed the original data into five components; first harmonic VEP, second harmonic VEP, dominant rhythm, slower noise and others. Characteristics for the depression of dominant rhythm and the amplitude of VEP were quantitatively analyzed from the decomposed component by the MPA EEG model. Effectiveness of the proposed decomposition method was also investigated.
Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section, 1995
In order to investigate the interaction of sensory electrophysiologic fields arising from the adj... more In order to investigate the interaction of sensory electrophysiologic fields arising from the adjacent second (II) and third (III) fingers and the distant second and fifth (V) fingers, direct recordings of somatosensory evoked potentials (SEPs) were performed from the sensory and motor cortices, the sensory thalamic nucleus (nucleus ventralis caudalis, VC) and the cuneate nucleus in humans during neurosurgical operations. Electrical stimulation was given to the II, III or V fingers individually, and also to pairs of either the II and III fingers or the II and V fingers simultaneously. The interaction ratio (IR) was devised as the ratio of amplitude attenuation caused by the simultaneous stimulation to two fingers compared with the amplitude of the arithmetically summed SEPs to the individual stimulation of two fingers. The IRs were calculated on N20 and P25 from the sensory cortex, P22 from the motor cortex, P17thal from the VC, and N16cune and P35cunefrOm the cuneate nucleus. With both stimulations to the II and III fingers and the II and V fingers, P25 showed the greatest IR, followed by P22, then by P17th ~, while N16cune exhibited the smallest IR. N20 and P35cune showed similar IRs and significantly greater IRs with II and III finger stimulation compared with II and V finger stimulation. These results thus indicate that the interaction of somatosensory impulses occurs in several structures along the sensory pathway in CNS, including the cuneate nucleus, the sensory thalamic nucleus, as well as sensory and motor cortices, with the greatest IRs in the cerebral cortices and the weakest ones in the brain-stem. They also suggest that the receptive fields of the fingers in the cortical area generating N20 are arranged according to the order of the fingers while those in the generating sites for cortical P25 and P22, thalamic P17th~l and cuneate N16cu~e tend to be arranged in clusters, while P35c,~e is possibly modulated by the somatosensory cortex through a long-loop feedback pathway.
Although dysfunction of the sensory systems in sporadic amyotrophic lateral sclerosis (ALS) has b... more Although dysfunction of the sensory systems in sporadic amyotrophic lateral sclerosis (ALS) has been reported, the clinical characteristics of such cases still remain unknown. We therefore performed a clinico-electrophysiological analysis of sporadic ALS patients. Twelve ALS patients (aged 36-66 years), who had their somatosensory evoked potentials (SEPs) evaluated, were reviewed and their clinical characteristics were delineated. In addition, needle EMG, sensory nerve conduction velocities, motor evoked potentials (MEPs) and cervical MRI or plain X-ray of the neck were also recorded. Three cases were segregated from the other 9 patients because of predominant upper motor neuron signs with pseudobulbar palsy and abnormal posterior tibial nerve and/or median nerve SEPs. The MEPs were also abnormal in these 3 patients and the brainstem auditory evoked potentials were abnormal in one patient. EMG revealed less involvement in the lower motor neurons. Sporadic ALS with a predominant uppe...
Clinical Neurophysiology at the Beginning of the 21st Century, 11th International Congress of Electromyography and Clinical Neurophysiology, 2000
Publisher Summary Two principles in neuronal organization are pivotal to the understanding of vis... more Publisher Summary Two principles in neuronal organization are pivotal to the understanding of visual cortical processing: multiple parallel pathways and anatomical segregation of functionally specialized areas. The functional specialization of separate anatomical areas is confirmed by the effect of selected lesions producing deficits limited to color, spatial perception, or movement. It must be acknowledged that anatomical segregation is far from absolute and some lesions limited to specific areas only produce a temporary effect with subsequent recovery. Anatomical studies in primates have demonstrated 305 interconnecting pathways among the various visual areas. Question remains on the reconciliation of the hypotheses of multiple parallel channels, functional specialization, and hierarchical organization with the unitary integrated phenomenology of visual experience. The hypothesis of a distributed network may bring these separate concepts together. The visual system is modular; modules are added as needed to increase information processing and each module operates via a distributed network with crucial nodal points (or information bottlenecks). The most crucial nodal point is VI where all incoming information is received and then distributed to the other areas of the network. Lesions at crucial nodal points are likely to produce specific visual deficits for example, homonymous hemianopia in VI lesions. Lesions in the network may be silent or transient. Other modules or network connections may compensate for the damaged area (plasticity).
We investigated the nature of negative potential in the frontal region with an approximate latenc... more We investigated the nature of negative potential in the frontal region with an approximate latency of 100 ms ('frontal negativity') as a component of pattern-reversal visual evoked potential (PVEP) in healthy human subjects. It was recorded by stimulation of one-half of the visual field, with different reference electrodes and with experimental manipulations of the stimulating visual field ('central scotomata' and ' peripheral constriction'). A negative potential field was demonstrated to be localized in the frontal region, and its physiological properties detected by the visual field manipulations were shown to be different from those of the occipital positive (P100) and negative (N105) components of PVEP. We conclude, therefore, that frontal negativity of PVEP is an actual electrical event generated in the frontal region, independent of P100 and N105.
schizophrenia. The LFOs measured by the blood-related brain functional imaging methods can be rel... more schizophrenia. The LFOs measured by the blood-related brain functional imaging methods can be related to those in systemic cardiovascular dynamics. We previously analyzed the information transfer among LFOs around 0.1 Hz in the hemoglobin concentration change (HbCC) in the cerebral cortex, the heart rate (HR), and the mean arterial blood pressure (ABP) to understand the origin of spontaneous LFOs in cerebral hemodynamics. The analysis suggested that the LFOs in oxygenated HbCC (oxy-HbCC), a parameter of cerebral hemodynamics, originated mainly from the cerebral components, cerebral autoregulation and energetic metabolism. In this study we examined the information–theoretic relationships between LFOs in cerebral hemodynamics and cerebral pulse rate (CPR) to quantify the contribution of cerebral blood flow autoregulation to the genesis of the LFOs. Data for analysis were obtained from simultaneous measurements with optical topography, laser Doppler flowmetry electrocardiography, and infrared finger plethysmography under rest conditions. The CPR data were obtained from the pulsatile components in oxy-HbCC. As information-theoretic measures, we used the transfer entropy (TE) and the intrinsic transfer entropy (ITE). The present analysis demonstrated that ITE from CPR to oxy-HbCC was 23%, whereas ITE from HR to oxy-HbCC was 6%. This suggests that the cerebral blood flow autoregulation can account for about 20% of the information carried with oxy-HbCC. In addition, the analysis of their power spectra supported this result in the sense that the power spectrum of oxy-HbCC was more similar to that of CPR than to that of HR.
CHA microinjection into the anterior hypothalamus elicited the most marked body temperature decre... more CHA microinjection into the anterior hypothalamus elicited the most marked body temperature decrease compared with other regions such as the preoptic area, dorsomedial hypothalamus and posterior hypothalamus. Expression level of A1 receptor mRNA in anterior hypothalamus decreased transiently after 10 h hibernation onset. However, expression level of A1 receptor protein did not decreased across the hibernation cycles. These results suggest that adenosine lower Tb of Syrian hamsters by activation of A1 receptors in anterior hypothalamus during entrance phase of hibernation.
Thirty-five Japanese patients with relapsing remitting multiple sclerosis (RRMS) and 11 Japanese ... more Thirty-five Japanese patients with relapsing remitting multiple sclerosis (RRMS) and 11 Japanese patients with primary progressive MS (PPMS) were compared by a combined clinical, magnetic resonance imaging (MRI) and multimodality evoked potential (MEP) study. Patients with PPMS showed a more common occurrence of gait disturbance as the initial symptoms as well as a more common occurrence of cerebellar symptomatology than did those with RRMS, while spinal cord symptomatology was frequently observed in both conditions. On brain MRI, patients with PPMS had 3 times more lesions than did those with RRMS (P < 0.001, chi 2-test). The percentage of infratentorial lesions was also significantly higher in PPMS than in RRMS on MRI. Moreover, we found a significantly higher frequency of abnormal records in visual, brainstem auditory and somatosensory evoked potentials in PPMS than in RRMS. Interestingly, clinically unexpected abnormalities were significantly more common in PPMS than in RRMS throughout all modalities of MEPs. Thus, in Eastern MS, there exists a distinction between PPMS and RRMS in the MRI and MEP findings as well as in the clinical findings. Our result therefore suggest that there may be two distinct subtypes in MS.
Journal of Neurology, Neurosurgery & Psychiatry, 1998
An occurrence of acute localised myelitis was recently seen in four adult patients with atopic de... more An occurrence of acute localised myelitis was recently seen in four adult patients with atopic dermatitis who had hyperIgEaemia and mite antigen specific IgE. The total and mite antigen specific IgE was therefore studied in serum samples from 19 consecutive patients with acute localised myelitis of unknown aetiology, 56 patients with clinically definite multiple sclerosis, and 40 healthy controls. The total IgE concentration was significantly higher in acute localised myelitis (me-dian=360 U/ml) than in multiple sclerosis (median=52 U/ml, p<0.0001) and the controls (median=85 U/ml, p=0.0002). The specific IgE to Dermatophagoides pteronyssinus was found more often in patients with acute localised myelitis (95%) than in patients with multiple sclerosis (34%, p<0.0001) and the controls (35%, p<0.0001) and the specific IgE to Dermatophagoides farinae was similar (acute localised myelitis 79%, multiple sclerosis 29% (p<0.0001), controls 30%, (p=0.0003). Atopic dermatitis coexisted more commonly in patients with acute localised myelitis (37%) than in patients with multiple sclerosis (0%, p<0.0001) and the controls (7.5%, p=0.0089). Therefore, acute localised myelitis with hyperIgEaemia, in which atopy to mite antigens seems to exist, may be a distinct subtype of allergic myelitis-that is, atopic myelitis.
Although lentivirus vectors hold promise for ocular gene therapy, they also have potential safety... more Although lentivirus vectors hold promise for ocular gene therapy, they also have potential safety issues, particularly in the case of the current human immunodeficiency virus-based vectors. We recently developed a novel lentivirus vector derived from the nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to minimize these potentials. In this preclinical study, we evaluated whether SIV vector could be efficiently and safely applicable to retinal gene transfer by assessing the transgene expression, retinal function and histology over a 1-year period following subretinal injection in adult rats. The functional assessment via electroretinogram after both titers of SIV-lacZ (2.5 Â 10 7 or 2.5 Â 10 8 transducing units/ml) injection revealed both the dark and light adaptations to soon be impaired, in a dose-dependent manner, after a buffer injection as well, and all of them recovered to the control range by day 30. In both titers tested, the retinas demonstrated a frequent transgene expression mainly in the retinal pigment epithelium; however, the other retinal cells rarely expressed the transgene. Retinas exposed to a low titer virus showed no significant inflammatory reaction throughout the observation period, and also maintained the transgene expression over a 1-year period. In the retinas exposed to a high titer virus, however, mononuclear cell infiltration persisted in the subretinal area, and the retina that corresponded to the injected area finally underwent degeneration by around day 90. No retinal neoplastic lesions could be found in any animals over the 1-year period. We thus propose that SIV-mediated stable gene transfer might be useful for ocular gene transfer; however, more attention should be paid to avoiding complications when administering high titer lentivirus to the retina.
IN an attempt to examine dynamic involvement of multiple brain regions in the auditory selective ... more IN an attempt to examine dynamic involvement of multiple brain regions in the auditory selective attention process, negative difference wave (Nd) generators were assessed using a high-resolution EEG system (128 ch) and scalp current density (SCD) analysis. Ten normal volunteers participated in the study. Eventrelated potentials were recorded during a selective attention task. Sequential SCD mappings revealed that current sinks were located in the bilateral temporal regions at 160 ms subsequent to the onset of stimuli, shifting the dipole orientation more tangentially to the scalp at around 220 ms. Moreover, a current sink was demonstrated in the midfrontal region at around 320 ms. These ®ndings con®rm that different cortical regions are sequentially involved in the auditory selective attention process. NeuroReport 10:3837±3842 #
Posters were no significant differences in both latency and amplitude between the two groups. Con... more Posters were no significant differences in both latency and amplitude between the two groups. Conclusions: These findings suggested that an early automatic processing specific to fearful faces within the occipital areas (probably, the primary visual cortex) was impaired in ASD adults. Therefore, we conclude that the explicit social abnormalities observed in individuals with ASD can be explained by such deficits in the preattentive face processing within the lower visual areas.
Posters face of 18 persons (8 males and 10 females). Frontal and deviated faces were presented wi... more Posters face of 18 persons (8 males and 10 females). Frontal and deviated faces were presented with a fixed gaze direction, followed by an apparent movement of eyes either toward the subject or away from the subject. Furthermore, eyes photographs with the apparent motion cut out from the face were also used as the stimulus. Subjects were eighteen student volunteers (8 males and 9 females). In 'Direct gaze condition', gaze direction moved toward the subject either from 30 degrees right or left location, and in 'Averted gaze condition', it moved away 30 degrees either right or left direction from the subject. EEG were recorded from Fz, Cz, Pz, C3, C4, T3, T4, T5 and T6 locations referred to nose-tip. The negative ERP component about 170 ms after stimulus onset (N170) were observed to the apparent movement of eyes both for face and eyes stimulus. This component was larger in 'Direct gaze condition' than in 'Averted gaze condition', suggesting that gaze contact relates to the specific processing different from averted gaze. Furthermore this N170 was interacted with the diretion of face.
Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section, 1991
Pattern visual evoked potentials (VEPs) to transient and steady-state stimulation were recorded i... more Pattern visual evoked potentials (VEPs) to transient and steady-state stimulation were recorded in 10 normal subjects at 4 levels of luminance (180, 57, 22 and 11 cd/m2). VEPs were also recorded in 5 patients with optic neuropathy at a fixed luminance (180 cd/m2). The relationship between P100 latency of transient VEPs (T-VEPs) and the phase of steady-state VEPs (S-VEPs) was analyzed. As luminance decreased in normal subjects, P100 latency was prolonged and the phase lag increased. A significant linear relationship between the P100 latency and phase was found. Patients showed both the prolonged P100 latency and the delayed phase. The simple linear regression line of the phase-P100 latency function of normal subjects closely matched the patients&#39; values. These results suggest that changes in the phase may be equivalent to changes in the P100 latency. S-VEPs, therefore, may be clinically useful in assessing visual function.
2009 ICME International Conference on Complex Medical Engineering, 2009
Dominant rhythm in electroencephalographic (EEG) records is seen at the posterior to occipital re... more Dominant rhythm in electroencephalographic (EEG) records is seen at the posterior to occipital region as a primary component of background activity during waking state with closed eyes and is decreased or disappeared by the exogenous factors such as visual stimuli to eyes and so on. Visual evoked potential (VEP) can also be seen in EEG at the posterior to occipital regions during photic stimulation (PS). Frequency components of VEP are depended upon the frequency of stimuli and that of dominant rhythm in case of healthy adult is around 10 Hz. Therefore, components of VEP and dominant rhythm are almost overlapped when the frequency of photo stimuli is near around 10 Hz. VEP component can be extracted from the background activity by using the averaging method, but the accurate estimation of dominant rhythm component in such condition has difficulties due to the overlapping of both components in frequency domain. Some of the authors have proposed the EEG model with Markov process amplitude (MPA EEG model) in the past. The MPA EEG model has possibilities to separate the components that construct the original EEG into each one in the frequency domain. In this study, component decomposition of VEP and dominant rhythm of recorded EEG was done by using the MPA EEG model. EEGs with PS were recorded from three healthy young adults. Five seconds continuous EEG time series with PS and without PS were selected from the original data, and were transferred to the periodogram information by the FFT method. Then, the model parameters were calculated. The initial values of model parameters were determined from the periodogram of raw EEG during PS, and were optimized by Fletcher-Powell method. In the original data under PS with 10 Hz, VEP component and dominant rhythm component were overlapped each other. Proposed method decomposed the original data into five components; first harmonic VEP, second harmonic VEP, dominant rhythm, slower noise and others. Characteristics for the depression of dominant rhythm and the amplitude of VEP were quantitatively analyzed from the decomposed component by the MPA EEG model. Effectiveness of the proposed decomposition method was also investigated.
Electroencephalography and Clinical Neurophysiology/Evoked Potentials Section, 1995
In order to investigate the interaction of sensory electrophysiologic fields arising from the adj... more In order to investigate the interaction of sensory electrophysiologic fields arising from the adjacent second (II) and third (III) fingers and the distant second and fifth (V) fingers, direct recordings of somatosensory evoked potentials (SEPs) were performed from the sensory and motor cortices, the sensory thalamic nucleus (nucleus ventralis caudalis, VC) and the cuneate nucleus in humans during neurosurgical operations. Electrical stimulation was given to the II, III or V fingers individually, and also to pairs of either the II and III fingers or the II and V fingers simultaneously. The interaction ratio (IR) was devised as the ratio of amplitude attenuation caused by the simultaneous stimulation to two fingers compared with the amplitude of the arithmetically summed SEPs to the individual stimulation of two fingers. The IRs were calculated on N20 and P25 from the sensory cortex, P22 from the motor cortex, P17thal from the VC, and N16cune and P35cunefrOm the cuneate nucleus. With both stimulations to the II and III fingers and the II and V fingers, P25 showed the greatest IR, followed by P22, then by P17th ~, while N16cune exhibited the smallest IR. N20 and P35cune showed similar IRs and significantly greater IRs with II and III finger stimulation compared with II and V finger stimulation. These results thus indicate that the interaction of somatosensory impulses occurs in several structures along the sensory pathway in CNS, including the cuneate nucleus, the sensory thalamic nucleus, as well as sensory and motor cortices, with the greatest IRs in the cerebral cortices and the weakest ones in the brain-stem. They also suggest that the receptive fields of the fingers in the cortical area generating N20 are arranged according to the order of the fingers while those in the generating sites for cortical P25 and P22, thalamic P17th~l and cuneate N16cu~e tend to be arranged in clusters, while P35c,~e is possibly modulated by the somatosensory cortex through a long-loop feedback pathway.
Although dysfunction of the sensory systems in sporadic amyotrophic lateral sclerosis (ALS) has b... more Although dysfunction of the sensory systems in sporadic amyotrophic lateral sclerosis (ALS) has been reported, the clinical characteristics of such cases still remain unknown. We therefore performed a clinico-electrophysiological analysis of sporadic ALS patients. Twelve ALS patients (aged 36-66 years), who had their somatosensory evoked potentials (SEPs) evaluated, were reviewed and their clinical characteristics were delineated. In addition, needle EMG, sensory nerve conduction velocities, motor evoked potentials (MEPs) and cervical MRI or plain X-ray of the neck were also recorded. Three cases were segregated from the other 9 patients because of predominant upper motor neuron signs with pseudobulbar palsy and abnormal posterior tibial nerve and/or median nerve SEPs. The MEPs were also abnormal in these 3 patients and the brainstem auditory evoked potentials were abnormal in one patient. EMG revealed less involvement in the lower motor neurons. Sporadic ALS with a predominant uppe...
Clinical Neurophysiology at the Beginning of the 21st Century, 11th International Congress of Electromyography and Clinical Neurophysiology, 2000
Publisher Summary Two principles in neuronal organization are pivotal to the understanding of vis... more Publisher Summary Two principles in neuronal organization are pivotal to the understanding of visual cortical processing: multiple parallel pathways and anatomical segregation of functionally specialized areas. The functional specialization of separate anatomical areas is confirmed by the effect of selected lesions producing deficits limited to color, spatial perception, or movement. It must be acknowledged that anatomical segregation is far from absolute and some lesions limited to specific areas only produce a temporary effect with subsequent recovery. Anatomical studies in primates have demonstrated 305 interconnecting pathways among the various visual areas. Question remains on the reconciliation of the hypotheses of multiple parallel channels, functional specialization, and hierarchical organization with the unitary integrated phenomenology of visual experience. The hypothesis of a distributed network may bring these separate concepts together. The visual system is modular; modules are added as needed to increase information processing and each module operates via a distributed network with crucial nodal points (or information bottlenecks). The most crucial nodal point is VI where all incoming information is received and then distributed to the other areas of the network. Lesions at crucial nodal points are likely to produce specific visual deficits for example, homonymous hemianopia in VI lesions. Lesions in the network may be silent or transient. Other modules or network connections may compensate for the damaged area (plasticity).
We investigated the nature of negative potential in the frontal region with an approximate latenc... more We investigated the nature of negative potential in the frontal region with an approximate latency of 100 ms ('frontal negativity') as a component of pattern-reversal visual evoked potential (PVEP) in healthy human subjects. It was recorded by stimulation of one-half of the visual field, with different reference electrodes and with experimental manipulations of the stimulating visual field ('central scotomata' and ' peripheral constriction'). A negative potential field was demonstrated to be localized in the frontal region, and its physiological properties detected by the visual field manipulations were shown to be different from those of the occipital positive (P100) and negative (N105) components of PVEP. We conclude, therefore, that frontal negativity of PVEP is an actual electrical event generated in the frontal region, independent of P100 and N105.
schizophrenia. The LFOs measured by the blood-related brain functional imaging methods can be rel... more schizophrenia. The LFOs measured by the blood-related brain functional imaging methods can be related to those in systemic cardiovascular dynamics. We previously analyzed the information transfer among LFOs around 0.1 Hz in the hemoglobin concentration change (HbCC) in the cerebral cortex, the heart rate (HR), and the mean arterial blood pressure (ABP) to understand the origin of spontaneous LFOs in cerebral hemodynamics. The analysis suggested that the LFOs in oxygenated HbCC (oxy-HbCC), a parameter of cerebral hemodynamics, originated mainly from the cerebral components, cerebral autoregulation and energetic metabolism. In this study we examined the information–theoretic relationships between LFOs in cerebral hemodynamics and cerebral pulse rate (CPR) to quantify the contribution of cerebral blood flow autoregulation to the genesis of the LFOs. Data for analysis were obtained from simultaneous measurements with optical topography, laser Doppler flowmetry electrocardiography, and infrared finger plethysmography under rest conditions. The CPR data were obtained from the pulsatile components in oxy-HbCC. As information-theoretic measures, we used the transfer entropy (TE) and the intrinsic transfer entropy (ITE). The present analysis demonstrated that ITE from CPR to oxy-HbCC was 23%, whereas ITE from HR to oxy-HbCC was 6%. This suggests that the cerebral blood flow autoregulation can account for about 20% of the information carried with oxy-HbCC. In addition, the analysis of their power spectra supported this result in the sense that the power spectrum of oxy-HbCC was more similar to that of CPR than to that of HR.
CHA microinjection into the anterior hypothalamus elicited the most marked body temperature decre... more CHA microinjection into the anterior hypothalamus elicited the most marked body temperature decrease compared with other regions such as the preoptic area, dorsomedial hypothalamus and posterior hypothalamus. Expression level of A1 receptor mRNA in anterior hypothalamus decreased transiently after 10 h hibernation onset. However, expression level of A1 receptor protein did not decreased across the hibernation cycles. These results suggest that adenosine lower Tb of Syrian hamsters by activation of A1 receptors in anterior hypothalamus during entrance phase of hibernation.
Thirty-five Japanese patients with relapsing remitting multiple sclerosis (RRMS) and 11 Japanese ... more Thirty-five Japanese patients with relapsing remitting multiple sclerosis (RRMS) and 11 Japanese patients with primary progressive MS (PPMS) were compared by a combined clinical, magnetic resonance imaging (MRI) and multimodality evoked potential (MEP) study. Patients with PPMS showed a more common occurrence of gait disturbance as the initial symptoms as well as a more common occurrence of cerebellar symptomatology than did those with RRMS, while spinal cord symptomatology was frequently observed in both conditions. On brain MRI, patients with PPMS had 3 times more lesions than did those with RRMS (P &lt; 0.001, chi 2-test). The percentage of infratentorial lesions was also significantly higher in PPMS than in RRMS on MRI. Moreover, we found a significantly higher frequency of abnormal records in visual, brainstem auditory and somatosensory evoked potentials in PPMS than in RRMS. Interestingly, clinically unexpected abnormalities were significantly more common in PPMS than in RRMS throughout all modalities of MEPs. Thus, in Eastern MS, there exists a distinction between PPMS and RRMS in the MRI and MEP findings as well as in the clinical findings. Our result therefore suggest that there may be two distinct subtypes in MS.
Journal of Neurology, Neurosurgery & Psychiatry, 1998
An occurrence of acute localised myelitis was recently seen in four adult patients with atopic de... more An occurrence of acute localised myelitis was recently seen in four adult patients with atopic dermatitis who had hyperIgEaemia and mite antigen specific IgE. The total and mite antigen specific IgE was therefore studied in serum samples from 19 consecutive patients with acute localised myelitis of unknown aetiology, 56 patients with clinically definite multiple sclerosis, and 40 healthy controls. The total IgE concentration was significantly higher in acute localised myelitis (me-dian=360 U/ml) than in multiple sclerosis (median=52 U/ml, p<0.0001) and the controls (median=85 U/ml, p=0.0002). The specific IgE to Dermatophagoides pteronyssinus was found more often in patients with acute localised myelitis (95%) than in patients with multiple sclerosis (34%, p<0.0001) and the controls (35%, p<0.0001) and the specific IgE to Dermatophagoides farinae was similar (acute localised myelitis 79%, multiple sclerosis 29% (p<0.0001), controls 30%, (p=0.0003). Atopic dermatitis coexisted more commonly in patients with acute localised myelitis (37%) than in patients with multiple sclerosis (0%, p<0.0001) and the controls (7.5%, p=0.0089). Therefore, acute localised myelitis with hyperIgEaemia, in which atopy to mite antigens seems to exist, may be a distinct subtype of allergic myelitis-that is, atopic myelitis.
Although lentivirus vectors hold promise for ocular gene therapy, they also have potential safety... more Although lentivirus vectors hold promise for ocular gene therapy, they also have potential safety issues, particularly in the case of the current human immunodeficiency virus-based vectors. We recently developed a novel lentivirus vector derived from the nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to minimize these potentials. In this preclinical study, we evaluated whether SIV vector could be efficiently and safely applicable to retinal gene transfer by assessing the transgene expression, retinal function and histology over a 1-year period following subretinal injection in adult rats. The functional assessment via electroretinogram after both titers of SIV-lacZ (2.5 Â 10 7 or 2.5 Â 10 8 transducing units/ml) injection revealed both the dark and light adaptations to soon be impaired, in a dose-dependent manner, after a buffer injection as well, and all of them recovered to the control range by day 30. In both titers tested, the retinas demonstrated a frequent transgene expression mainly in the retinal pigment epithelium; however, the other retinal cells rarely expressed the transgene. Retinas exposed to a low titer virus showed no significant inflammatory reaction throughout the observation period, and also maintained the transgene expression over a 1-year period. In the retinas exposed to a high titer virus, however, mononuclear cell infiltration persisted in the subretinal area, and the retina that corresponded to the injected area finally underwent degeneration by around day 90. No retinal neoplastic lesions could be found in any animals over the 1-year period. We thus propose that SIV-mediated stable gene transfer might be useful for ocular gene transfer; however, more attention should be paid to avoiding complications when administering high titer lentivirus to the retina.
IN an attempt to examine dynamic involvement of multiple brain regions in the auditory selective ... more IN an attempt to examine dynamic involvement of multiple brain regions in the auditory selective attention process, negative difference wave (Nd) generators were assessed using a high-resolution EEG system (128 ch) and scalp current density (SCD) analysis. Ten normal volunteers participated in the study. Eventrelated potentials were recorded during a selective attention task. Sequential SCD mappings revealed that current sinks were located in the bilateral temporal regions at 160 ms subsequent to the onset of stimuli, shifting the dipole orientation more tangentially to the scalp at around 220 ms. Moreover, a current sink was demonstrated in the midfrontal region at around 320 ms. These ®ndings con®rm that different cortical regions are sequentially involved in the auditory selective attention process. NeuroReport 10:3837±3842 #
Posters were no significant differences in both latency and amplitude between the two groups. Con... more Posters were no significant differences in both latency and amplitude between the two groups. Conclusions: These findings suggested that an early automatic processing specific to fearful faces within the occipital areas (probably, the primary visual cortex) was impaired in ASD adults. Therefore, we conclude that the explicit social abnormalities observed in individuals with ASD can be explained by such deficits in the preattentive face processing within the lower visual areas.
Posters face of 18 persons (8 males and 10 females). Frontal and deviated faces were presented wi... more Posters face of 18 persons (8 males and 10 females). Frontal and deviated faces were presented with a fixed gaze direction, followed by an apparent movement of eyes either toward the subject or away from the subject. Furthermore, eyes photographs with the apparent motion cut out from the face were also used as the stimulus. Subjects were eighteen student volunteers (8 males and 9 females). In 'Direct gaze condition', gaze direction moved toward the subject either from 30 degrees right or left location, and in 'Averted gaze condition', it moved away 30 degrees either right or left direction from the subject. EEG were recorded from Fz, Cz, Pz, C3, C4, T3, T4, T5 and T6 locations referred to nose-tip. The negative ERP component about 170 ms after stimulus onset (N170) were observed to the apparent movement of eyes both for face and eyes stimulus. This component was larger in 'Direct gaze condition' than in 'Averted gaze condition', suggesting that gaze contact relates to the specific processing different from averted gaze. Furthermore this N170 was interacted with the diretion of face.
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Papers by S. Tobimatsu