Effect of transcranial magnetic stimulation on P300 of event-related potential

When the odd stimulation is presented, the positive component of electroencephalograph is induced at around 300 ms after the odd stimulation. This positive component is called P300. Many studies suggest that P300 may result from the summation of activity from multiple generators located in widespread cortical and subcortical areas. However, there is still no conclusive indication of the sources of P300. In this paper, we focus on the left supramaginal gyrus as one of the sources of P300. We investigated the temporal aspect of this area using TMS (transcranial magnetic stimulation). We investigated the relationship between the latency of the P300 and an effect of TMS when the left supramarginal gyrus was stimulated by TMS. In our previous study, we reported a method of removing stimulus artifact during TMS with Sample-and-Hold circuit and electroencephalogram (EEG) activity evoked by TMS could be measured successfully. In addition to this method, independent component analysis (ICA) was also applied to recorded EEG data in order to remove the stimulus artifact by off-line analysis. By using these methods, short latency (< 15 ms) EEG responses to TMS could be obtained. We stimulated the left supramarginal gyrus using a figure-eight coil during auditory oddball task. The TMS at 150 ms and 200 ms after the oddball sounds were presented. When the TMS was applied at 200 ms after the oddball stimulation, the peak response of P300 was delayed around 50 ms. Difference of the peak latency between the control measurement and the case of TMS applying at 150 ms was not significant. However, the differences of the peak latency of the control measurement and the peak latency of the measurement in the cases of TMS applying at 200 ms and 250 ms was significant (p<0.05). We considered that this delay was due to inhibiting to recognize the target stimulation.

Time change of perceptual reversal of ambiguous figures by rTMS

The aim of this study was to investigate the effect of stimulus frequency and number of pulses during rTMS (repetitive transcranial magnetic stimulation) on the phenomenon of perceptual reversal. Particularly, we focused on the temporal dynamics of perceptual reversal in the right SPL (superior parietal lobule), using the spinning wheel illusion. We measured the IRT (inter-reversal time) of perceptual reversal. To investigate whether stimulus frequency or the number of pulses is critical for the rTMS effect, we applied the following schedules over the right SPL and the right PTL (posterior temporal lobe): 0.25Hz 60 pulses, 0.25Hz 120pulses, 0.5Hz 120 pulses, and 1Hz 120 pulses biphasic rTMS at 90% of the resting motor threshold. As a control, we included a No-TMS condition. The results showed that rTMS with 0.25Hz 60 pulses over the right SPL caused shorter IRT. There were no significant differences between IRTs for rTMS with 0.25Hz 120 pulses, 0.5Hz 120 pulses or 1Hz 120 pulses over the right SPL. Comparing these results with those of a previous study, we found that an rTMS condition with 60 pulses causes shorter IRT; 240 pulses causes longer IRT; and 120 pulses does not change IRT. Therefore, when applying rTMS over the right SPL, the IRT of perceptual reversal is primarily affected by the number of pulses.

[Successful repair for impending ruptured subclavian artery aneurysm; report of a case]

Subclavian artery aneurysm is relatively rare. We report a case of an impending rupture of an atherosclerotic aneurysm of the extrathoracic subclavian artery. A 61-year-old male patient with right hemiparesis due to prior cerebral infarction was referred to our hospital for treatment of an enlarging pulsatile mass with continuous pain around the right clavicle. Computed tomography of the chest revealed a fusiform subclavian artery aneurysm with a maximum diameter of 58 mm. An emergency operation was performed following the diagnosis of an impending rupture of the right subclavian artery aneurysm. Using a continuous incision from the supra to sub-clavicular regions, the right subclavian artery aneurysm was replaced with a straight vascular graft, 12 mm in diameter. Although several postoperative complications, such as respiratory insufficiency and renal dysfunction occurred, he was transferred to a rehabilitation hospital on the 110th postoperative day.

[Emphysematous bulla with effusion due to Aspergillus infection; report of a case]

A 30-year-old man was admitted to our hospital due to infectious bulla. His chest X-ray and computed tomography (CT) showed bilateral multiple emphysematous bullae and a left bulla with effusion. He underwent partial lung resection including the bulla with video-assisted thoracic surgery. The bacterial diagnosis of the effusion was infection of Aspergillus. Further, Aspergillus was detected inside the wall in pathological diagnosis. Treatment with itraconazole 100 mg a day was started after surgery, and 6 months later the patient is well without recurrence.

Compressibility and polymorphism of α-As(4)S(4) realgar under high pressure

The energy-dispersive x-ray diffraction technique has been employed to study the structure and equation of state of realgar As(4)S(4) under pressures up to 8 GPa at room temperature. We have obtained pressure dependences of the unit cell parameters and volume for the monoclinic structure of realgar. An approximation of the equation of state through the Murnaghan equation gives the bulk modulus and its derivative, B(0) = 8.1 ± 0.5 GPa and B(0)(') = 9.0 ± 0.5, respectively. A comparison of the obtained values with the corresponding values for other molecular crystals is drawn and discussed. At a pressure of around 7 GPa, realgar showed a polymorph transition to a new molecular phase with a supposedly orthorhombic structure. Such identification is evidenced by the presence of geometrical correlations between the parameters of the parent monoclinic phase and those of the new phase, and the phase transition is likely to be associated with the removal of a monoclinic distortion in the unit cell.

Evaluation of the 24-hour profiles of physiological insulin, glucose, and C-peptide in healthy Japanese volunteers

BACKGROUND

Some studies have demonstrated the benefit of blood glucose control as close as possible to physiological conditions. Not enough reports have investigated in detail the 24-h plasma profiles of insulin/glucose/C-peptide. Here we investigated the 24-h plasma profiles of physiological insulin/glucose/C-peptide in healthy Japanese adults.

METHODS

In order to evaluate the 24-h profiles of physiological insulin/glucose/C-peptide profiles, 42 blood samples were taken from each subject in our group of healthy Japanese volunteers to measure the 24-h profile with three standardized meals.

RESULTS

Plasma glucose and insulin increased rapidly followed by a rapid decrease after each meal with little variation at night. The average peak values of insulin after each meal were as follows: 426.20 pmol/L (breakfast), 373.75 pmol/L (lunch), and 410.28 pmol/L (dinner). The average times to peak insulin were 0.651 h (breakfast), 0.677 h (lunch), and 0.689 h (dinner). The corresponding average maximum postprandial plasma glucose levels were 8.39 mmol/L (breakfast), 8.77 mmol/L (lunch), and 8.74 mmol/L (dinner). The average times to peak glucose were 0.738 h (breakfast), 0.650 h (lunch), and 0.625 h (dinner). The average maximum postprandial C-peptide levels were 2.64 nmol/L (breakfast), 2.55 nmol/L (lunch), and 2.67 nmol/L (dinner). No major differences were found in these parameters between the Caucasian and Japanese populations.

CONCLUSIONS

This is the first investigation to measure the 24-h profiles of insulin/glucose/C-peptide in healthy Japanese volunteers with standardized meals. It is hoped this information will provide useful reference for future research and clinical management.

[Anomalous origin of the right coronary artery from the ascending aorta]

The patient was a 77-year-old man. In June 2008, he underwent off-pump coronary artery bypass (OPCAB) for unstable angina Intraoperative epiaortic echo showed an anomalous origin of theright coronary artery from the ascending aorta 4 cm above the sinotubular junction (STJ). The right coronary artery traveled through the planned proximal anastomotic site of the saphenous vein graft (SVG). If diagnosis of the anomalous origin of the right coronary artery had not been made, there would have been a high likelihood that the right coronary artery could have been injured. Thus, the usefulness of epiaortic echo was reaffirmed. An anomalous origin of the coronary artery is a rare congenital anomaly and its incidence is approximately 1%. An anomalous origin of the right coronary artery is very rare from the ascending aorta 4 cm above the STJ and only a few cases have been reported. An anomalous origin of the coronary artery can cause serious complications affecting the prognosis after open heart surgery. Thus, such an anomalous origin needs to be considered in preoperative evaluation.

Viscosity behavior spanning four orders of magnitude in As-S melts under high pressure

Under compression, the As-S liquids are subject to transformations, including polymerization and metallization. We have measured the viscosity of the As-S liquids under high pressures. As a result, large viscosity variations by 4-5 orders of magnitude have been revealed. The viscosity values of the As-S liquids are moderate in the molecular state, very high in the covalent state, and low in the metallic state. Therefore, predicting the viscosity behavior in other melts under pressure is possible, which is of considerable importance for the physics of glass transition, geophysics, and material science.

Nature of the structural transformations in B2O3 glass under high pressure

We study high-pressure polyamorphism of B2O3 glass using x-ray diffraction up to 10 GPa in the 300-700 K temperature range, in situ volumetric measurements up to 9 GPa, and first-principles simulations. Under pressure, glass undergoes two-stage transformations including a gradual increase of the first B-O (O-B) coordination numbers above 5 GPa. The fraction of boron atoms in the fourfold-coordinated state at P<10 GPa is smaller than was assumed from inelastic x-ray scattering spectroscopy data, but is considerably larger than was previously suggested by the classical molecular dynamics simulations. The observed transformations under both compression and decompression are broad in hydrostatic conditions. On the basis of ab initio results, we also predict one more transformation to a superdense phase, in which B atoms are sixfold coordinated.

AsS melt under pressure: one substance, three liquids

An in situ high-temperature--high-pressure study of liquid chalcogenide AsS by x-ray diffraction, resistivity measurements, and quenching from melt is presented. The obtained data provide direct evidence for the existence in the melt under compression of two transformations: one is from a moderate-viscosity molecular liquid to a high-viscosity nonmetallic polymerized liquid at P approximately 1.6-2.2 GPa; the other is from the latter to a low-viscosity metallic liquid at P approximately 4.6-4.8 GPa. Upon rapid cooling, molecular and metallic liquids crystallize to normal and high-pressure phases, respectively, while a polymerized liquid is easily quenched to a new AsS glass. General aspects of multiple phase transitions in liquid AsS, including relations to the phase diagram of the respective crystalline, are discussed.