Appearance of bitemporal periodic EEG activity in the last stage of Gerstmann-Sträussler-Scheinker syndrome (Pro102Leu): A case report.

EEG findings in advanced Gerstmann-Sträussler-Scheinker syndrome (GSS) are shown. A 56-year-old woman developed GSS symptoms and was diagnosed as having GSS with the P102L mutation at age 58. During the early stage, there were no significant EEG findings. Her clinical condition worsened and she developed akinetic mutism at age 62. The patient died of pneumonia at age 65. EEGs were recorded annually from age 61 to 65. Bilateral independent periodic discharges (BIPDs) in both temporal areas appeared at age 64. No clinical seizures were noticed. MEG showed the sharp waves of BIPDs originated independently in each temporal lobe. Other causes of BIPDs were absent.

Role of beta-band resting-state functional connectivity as a predictor of motor learning ability.

It has been suggested that resting-state functional connectivity (rs-FC) between the primary motor area (M1) region of the brain and other brain regions may be a predictor of motor learning, although this suggestion is still controversial. In the work reported here, we investigated the relationship between M1 seed-based rs-FC and motor learning. Fifty-three healthy volunteers undertook random button-press and sequential motor learning tasks. Five-minute resting-state data acquisition was performed between the two tasks. Oscillatory neural activities during the random task and the rest period were measured using magnetoencephalography. M1 seed-based rs-FC was calculated for the alpha and beta bands using amplitude envelope correlation, in which the seed location was defined as an M1 position with peak event-related desynchronization value. The relationship between rs-FC and the performance of motor learning was examined using whole brain correlation analysis. The results showed that beta-band resting-state cross-network connectivity between the sensorimotor network and the core network, particularly the theory of mind network, affected the performance of subsequent motor learning tasks. Good learners could be distinguished from poor learners by the strength of rs-FC between the M1 and the left superior temporal gyrus, a part of the theory of mind network. These results suggest that cross-network connectivity between the sensorimotor network and the theory of mind network can be used as a predictor of motor learning performance.

Modulation of Motor Learning Capacity by Transcranial Alternating Current Stimulation.

Motor function can be modulated by transcranial alternating current stimulation (tACS) in alpha, beta, and high-gamma frequencies. However, few studies have investigated tACS-induced behavioral changes in combination with endogenous oscillatory neural activity in detail. Herein, we investigated the effect of tACS on motor learning capacity and endogenous oscillatory neural activity. Fifty-two healthy volunteers were randomly assigned to four stimulation groups (10 Hz, 20 Hz, 70 Hz, or sham) and performed a visually cued button press motor learning task before and after tACS, which was delivered at the left primary motor area. Oscillatory neural activities during the motor learning task were measured using magnetoencephalography (MEG). Following tACS, the capacity for motor learning was significantly increased for 70 Hz tACS compared to sham stimulation. Oscillation analysis revealed a significant increase in beta-band power after 70-Hz tACS but not in the other stimulation groups. Our finding that capacity for motor learning and endogenous oscillatory beta activity were modulated in parallel after 70-Hz tACS suggests that 70-Hz tACS may increase the motor learning capacity by cross-modulating beta oscillatory activity. Because high gamma and beta oscillatory activity have been shown to reflect the activity of excitatory and inhibitory interneuron, our results may derive from the modulation of excitatory and inhibitory interneurons in M1 by 70-Hz tACS.

Prolonged central sensory conduction time in patients with chronic arsenic exposure.

BACKGROUND: Many patients from Toroku, Japan, who have chronic arsenic exposure demonstrate whole-body sensory disturbance that is slightly more pronounced in the extremities. Although previous research in this population showed a mild peripheral neuropathy, it is unknown whether these patients have central nervous system impairment. To investigate the lesion sites underlying sensory disturbance related to chronic arsenic poisoning, we analyzed somatosensory evoked potentials (SEP). METHODS: Clinical features, nerve conduction study results, and median and/or tibial SEP were analyzed in patients with chronic arsenic exposure (total, 13 patients; median & tibial, 4; median, 5; tibial, 4) retrospectively. The SEP findings in patients were compared with those in normal controls. RESULTS: The median SEP results indicated a conduction delay between the proximal brachial plexus and the primary sensory cortex, and tibial SEP findings indicated a delay between the dorsal gray matter of the lumbosacral cord and the primary sensory cortex. CONCLUSION: This is the first study to identify an impairment of the central somatosensory pathway in patients with chronic arsenic exposure. Sensory disturbance in these patients is related not only to peripheral neuropathy but also to impairment of the central nervous system.

Effect of nisin (Nisaplin) on the growth of Listeria monocytogenes in Karashi-mentaiko (Red-pepper Seasoned Cod Roe).

The influence of Nisaplin, which contains 2.5% nisin, on the growth of Listeria monocytogenes in Karashi-mentaiko (red-pepper seasoned cod roe) was investigated. The MICs of Nisaplin for L. monocytogenes (10(8) CFU/mL) were measured; seven isolates showed a value of 1,600 microg/mL and one isolate showed a value of 800 microg/mL. All L. monocytogenes isolates had a MIC of 800 microg/mL at 10(6) CFU/mL. The number of L. monocytogenes in Karashi-mentaiko stored at 4 degrees C was decreased by Nisaplin added at 60 and 600 microg/g. These results indicated that Nisaplin effectively inhibits the growth of L. monocytogenes in Karashi-mentaiko.

Bacterial communities in petroleum oil in stockpiles.

Bacterial communities in crude-oil samples from Japanese oil stockpiles were investigated by 16S rRNA gene cloning, followed by denaturing gradient gel electrophoresis (DGGE) analysis. 16S rRNA genes were successfully amplified by PCR after isooctane treatment from three kinds of crude-oil sample collected at four oil stockpiles in Japan. DGGE profiles showed that bacteria related to Ochrobactrum anthropi, Burkholderia cepacia, Stenotrophomonas maltophilia, Propionibacterium acnes, and Brevundimonas diminuta were frequently detected in most crude-oil samples. The bacterial communities differed in the sampling time and layer. Among the predominant bacteria detected in the crude oil, only three species were found for bacteria isolated on agar plates and were related to Burkholderia, Stenotrophomonas, and Propionibacterium, while Ochrobactrum sp. could not be isolated although this species seemed to be the most abundant bacterium in crude oil from the DGGE profiles. Using an archaea-specific primer set, methanogens were found in crude-oil sludge but not in crude-oil samples, indicating that methanogens might be involved in sludge formation in oil stockpiles.