Motor Learning Based on Oscillatory Brain Activity Using Transcranial Alternating Current Stimulation: A Review

Developing effective tools and strategies to promote motor learning is a high-priority scientific and clinical goal. In particular, motor-related areas have been investigated as potential targets to facilitate motor learning by noninvasive brain stimulation (NIBS). In addition to shedding light on the relationship between motor function and oscillatory brain activity, transcranial alternating current stimulation (tACS), which can noninvasively entrain oscillatory brain activity and modulate oscillatory brain communication, has attracted attention as a possible technique to promote motor learning. This review focuses on the use of tACS to enhance motor learning through the manipulation of oscillatory brain activity and its potential clinical applications. We discuss a potential tACS-based approach to ameliorate motor deficits by correcting abnormal oscillatory brain activity and promoting appropriate oscillatory communication in patients after stroke or with Parkinson\u27s disease. Interpersonal tACS approaches to manipulate intra- and inter-brain communication may result in pro-social effects and could promote the teaching-learning process during rehabilitation sessions with a therapist. The approach of re-establishing oscillatory brain communication through tACS could be effective for motor recovery and might eventually drive the design of new neurorehabilitation approaches based on motor learning

High temperature expansion in supersymmetric matrix quantum mechanics

We formulate the high temperature expansion in supersymmetric matrix quantum mechanics with 4, 8 and 16 supercharges. The models can be obtained by dimensionally reducing N=1 U(N) super Yang-Mills theory in D=4,6,10 to 1 dimension, respectively. While the non-zero frequency modes become weakly coupled at high temperature, the zero modes remain strongly coupled. We find, however, that the integration over the zero modes that remains after integrating out all the non-zero modes perturbatively, reduces to the evaluation of connected Green's functions in the bosonic IKKT model. We perform Monte Carlo simulation to compute these Green's functions, which are then used to obtain the coefficients of the high temperature expansion for various quantities up to the next-leading order. Our results nicely reproduce the asymptotic behaviors of the recent simulation results at finite temperature. In particular, the fermionic matrices, which decouple at the leading order, give rise to substantial effects at the next-leading order, reflecting finite temperature behaviors qualitatively different from the corresponding models without fermions.Comment: 17 pages, 13 figures, (v2) some typos correcte

Expression and Function of Inducible Costimulator on Peripheral Blood CD4 ؉ T Cells in Behçet's Patients with Uveitis: A New Activity Marker?

PURPOSE. Inducible costimulator (ICOS) is an important costimulatory molecule involved in T-cell activation. In this study, the role of ICOS in the pathogenesis of uveitis in Behçet's disease (BD) was investigated. METHODS. Peripheral blood mononuclear cells (PBMCs) were obtained from BD patients with uveitis in the active or remission phase and in healthy subjects. Total RNA was isolated from PMBCs, and mRNA expression was analyzed on an oligonucleotide microarray. ICOS expression on CD4 ϩ T cells was determined by flow cytometry, and the functional costimulatory effect of ICOS/B7RP-1 interaction was assessed on stimulation with concanavalin A (conA) or IRBP in the presence or absence of anti-ICOS mAb. RESULTS. As the result of microarray analysis, ICOS in PBMCs showed the greatest difference in expression in BD patients with uveitis compared with healthy control subjects. ICOS expression on CD4 ϩ T cells in BD patients with uveitis was significantly higher than that in healthy individuals, both before and after conA stimulation. Among the BD patients, ICOS expression on CD4 ϩ T cells was significantly higher in those with active uveitis than in those with remitted uveitis. Blockade of ICOS/B7-related protein-1 (B7RP-1) interaction by anti-ICOS mAb significantly decreased IFN-␥, IL-17, and TNF-␣ production by PBMCs when stimulated with conA or IRBP in BD with active uveitis. CONCLUSIONS. High ICOS expression in BD patients with uveitis contributed to the upregulation of IFN-␥, IL-17, and TNF-␣ production, suggesting that abnormal ICOS costimulation may play an immunopathologic role in the pathogenesis of uveitis in BD. (Invest Ophthalmol Vis Sci. 2010;51:5099 -5104) DOI: 10.1167/iovs.10-5286 E ndogenous uveitis such as Behçet's disease (BD), VogtKoyanagi-Harada syndrome, sympathetic ophthalmia, birdshot retinochoroidopathy, and sarcoidosis is a potentially blinding disease in humans and is responsible for 10% to 15% of the acquired blindness in Japan. 1 Although endogenous uveitis covers a spectrum of clinical entities, all forms are believed to share immunohistologic similarities characterized by the infiltration of mainly T cells. Behçet's disease (BD) is a systemic inflammatory disease characterized by oral and genital ulcers as well as ocular, cutaneous, arthritic, vascular, and neurologic lesions. 3-5 An increasing number of reports indicate that aberrant cellular immunity, such as pathogenic CD4 ϩ T-cell[b]-mediated autoimmunity via the Th1/Th17 pathway, plays a key role in the pathophysiological process in BD with uveitis, 6 -10 although the mechanisms of ocular inflammation in BD remain largely unknown. During recent years, the understanding of immunologic mechanisms involved in uveitis has advanced greatly through investigations of experimental autoimmune uveoretinitis (EAU), an animal model of human uveitis that can be induced by immunization of susceptible animals with interphotoreceptor retinoid-binding protein (IRBP) or with an eye-specific retinal antigen or by adoptive transfer of CD4 ϩ T cells specific for retinal antigens. 11 EAU resembles certain human uveitic conditions in various aspects 14,15 Although CD28 regulation has substantial effects on immunity, its function appears to reside predominantly in the control of primary, but not secondary, immune responses in various autoimmune diseases. 16 -18 The CD28 homolog inducible costimulator (ICOS) has recently been identified as a novel member of the CD28 costimulator family and is expressed by activated T cells in both humans and mice. To identify new genes that may cause or contribute to the disease process of ocular BD, we used cDNA microarrays that provide the expression profile of more than 54,000 genes, some of which are immune-related, whereas others are involved in the cell cycle, cell growth, intracellular signaling, cellular adhesion, and transport, and we compared the expression profiles of healthy individuals and patients. One of the genes found to be upregulated in patients with ocular BD is ICOS, an activation marker expressed on activated T cells that binds B7RP-1-expressing monocytes. The engagement of ICOS with B7RP-1 along with an appropriate antigen provide a positive signal that promotes T-cell differentiation, cytokine secretion, and effector function in the absence of CD28. ϩ T cells and B7RP-1 expressed on infiltrating APCs are upregulated directly after disease onset. 30 Therefore, we speculated that in active BD, pathogenic CD4 ϩ T cells that infiltrate the eye express ICOS in the inflamed eye and would be an appropriate target for the treatment of human ocular BD. Moreover, we have demonstrated that blockade of the ICOS/ B7RP-1 costimulatory pathway inhibits ocular inflammation in the effector phase of murine EAU. 30 Therefore, to investigate the role of ICOS in the pathogenesis of ocular BD, we assessed its expression on peripheral blood CD4 ϩ T cells and functional roles in patients with ocular BD. The results suggest that upregulation of ICOS is associated with the pathogenesis of uveitis in BD. MATERIALS AND METHODS PBMC Samples Thirty-five patients with BD (27 men and 8 women, mean age; 37.8 Ϯ 11.1 years) were enrolled in the study Heparinized blood samples were obtained from patients and healthy individuals, and PBMCs were isolated within 2 hours by density gradient centrifugation. The PBMCs were washed twice and resuspended at 1 ϫ 10 6 cells/mL in complete medium (RPMI 1640 supplemented with 10% fetal calf serum, 1 mM L-glutamine, 100 U/mL penicillin, and 100 g /mL streptomycin). Cell suspension was dispensed in 24-well plates (Falcon; BD Biosciences, Mountain View, CA) at 1 mL/well and incubated with or without concanavalin A (ConA; 10 g/mL) for 12 hours. Analysis of Gene Expression with cDNA Array Gene expression profile of human PBMCs was analyzed by microarray, as described previously. 37 Briefly, total RNA was isolated from pooled PBMCs obtained from seven patients with BD and active uveitis by an extraction method (Isogen Nippon Gene, Tokyo, Japan), and portions (2 g) of the preparation were subjected to amplification of mRNA with T7 RNA polymerase. Biotin-labeled cRNA (10 g) synthesized from the amplified RNA was subjected to hybridization with the Human Whole Genome Bioarray chip (Amersham Biosciences, Piscataway, NJ) that contains oligonucleotides corresponding to a total of approximately 55,585 human genes. Detection and digitization of hybridization signals were performed (G2565; Agilent Technologies, San Diego, CA) and analyzed (CodeLink Expression Analysis software version 4.0; Amersham Biosciences). The microarray data of various costimulatory molecules are summarized in Reagents FITC-conjugated anti-human CD4 (L3T4) was purchased from eBioscience (San Diego, CA), and anti-human ICOS (DX29) from BD PharMingen (San Diego, CA). ConA was obtained from Vector Laboratories (Burlingame, CA). Preparation of IRBP Fresh swine IRBP was purified according to the method described by Fukai et al. Immunofluorescence and Flow Cytometry The results of ICOS gene expression obtained from microarray were confirmed by flow cytometry. PMBCs were isolated by density gradient centrifugation of heparinized blood samples obtained from patients and healthy individuals. Each PBMC sample was divided into two aliquots: one for direct flow cytometry analysis of ICOS expression and the other for flow cytometry analysis after activation with conA at 10 g/mL for 12 hours. ICOS analysis was performed by using the following procedures: A cocktail of FITC-conjugated anti-CD4 and PE-conjugated anti-ICOS was added to the PBMCs. After the cells were washed with PBS, the stained cells (live-gated based on forward-and sidescatter profiles and propidium iodide exclusion) were passed through a flow cytometer (FACSCalibur; BD Biosciences, San Jose, CA) and the results analyzed (CellQuest program; BD Biosciences). ICOS expression on human CD4 ϩ T cells was calculated by gating for the CD4 ϩ T cell population, and 10,000 cells were analyzed in each experiment. Cytokine Assay Purified PBMCs (5 ϫ 10 5 /well) from BD patients with active uveitis were cultured in 96-well microtiter plates, with or without stimulation with conA (3 g/mL) or IRBP (10 g/mL) plus anti-ICOS mAb (10 g/mL) or control IgG at 37°C for 48 hours. The unstimulated PBMCs served as negative control samples. After stimulation, cell-free supernatants were collected at 48 hours and assayed for IFN-␥, TNF-␣, IL-2, and IL-6 by cytometric bead array (CBA) kits (BD PharMingen) and IL-17 by ELISA (Human IL-17 Quantikine ELISA kit; R&D Systems, Minneapolis, MN), according to the manufacturers' instructions. The minimum levels detected by CBA kits in either the culture supernatant or serum/plasma were 2.6 pg/mL for IL-2, 3.0 pg/mL for IL-6, 7.1 pg/mL for IFN-␥, and 2.8 pg/mL for TNF-␣; the minimum level in the IL-17 ELISA was 7.8 pg/mL. In a preliminary study, serial concentrations of conA (1, 3, 5, and 10 g/mL) or IRBP (1, 5, and 10 g/mL) were used in the assays. The results showed that optimal concentrations of cytokines were obtained at a concentration of 3 g/mL for conA and 10 g/mL for IRBP, as previously described. Statistical Analysis Data were analyzed (JMP 5; SAS Institute, Inc., Cary, NC) and the results expressed as the mean Ϯ SD. Statistical analysis was performed by using a paired or unpaired t-test. P Ͻ 0.05 was considered significant. RESULTS Analysis of Microarray Results in BD Patients with Active Uveitis To identify the genes involved in the pathogenesis of ocular BD, we compared phosphorescent images of the arrays hybridized with cDNA probes generated from RNA preparations from BD patients with active uveitis and healthy individuals. The array membrane that we used contained 360 positive bacterial controls and 384 negative controls. All positive controls were detected on the microarray. No signals were observed for the negative spots, indicating that the hybridization was highly specific. The DNA screening can evaluate more than 54,000 genes for a single sample. Among these genes, we focused on the immune-related ones, especially those of costimulatory molecules. Among the seven genes of costimulatory molecules, ICOS showed the greatest difference in expression in BD patients with active uveitis compared with that in healthy control subjects ICOS Expression on CD4 ؉ T Cells of BD Patients with Uveitis Flow cytometry was performed to confirm the results of gene array analysis. ICOS expression (median fluorescence intensity [MFI] of ICOS on CD4 ϩ T cells; Comparison of ICOS Expression on CD4 ؉ T Cells in BD Patients with Active or Inactive Uveitis Next, we compared ICOS expression on CD4 ϩ T cells in BD patients with active or inactive uveitis. ICOS expression (MFI of ICOS on CD4 ϩ T cells, Cytokine Production Stimulated with ConA and Uveitogenic Antigen To determine whether ICOS has functional costimulatory activity, we first measured the amounts of pathogenic Th1 and Th17 cytokines (IFN-␥, IL-17, TNF-␣, IL-6, and IL-2) produced by nonspecific stimulation (conA) of PBMCs obtained from BD patients with active uveitis. When ICOS costimulation was blocked with anti-ICOS mAb, the amounts of IFN-␥, IL-17, and TNF-␣ (Figs. 3A-C) produced by PBMCs were both significantly reduced. Since PBMCs from BD patients are known to be sensitized to the two most uveitogenic retina-specific antigens, S-antigen and IRBP, 1 we then examined the amounts of pathogenic Th1 and Th17 cytokines produced by stimulation with swine IRBP protein as the specific antigen. DISCUSSION The precise pathogenesis of uveitis associated with BD is unknown. Accumulated data obtained from animal models such as EAU suggest that Th1 and Th17 cells have major roles IOVS, October 2010, Vol. 51, No. 10 New Activity Marker for Ocular Behçet's Disease 5101 Downloaded from iovs.arvojournals.org on 06/30/2019 in its pathogenesis. We have previously shown that blockade of the ICOS ϩ costimulatory pathway has an ameliorating effect during the effector phase of EAU, by suppressing the expansion and effector function of pathogenic Th1 cells. In conclusion, our data provide additional evidence of the potential utility of ICOS expression on CD4 ϩ T cells as a marker of disease activity and as a promising therapeutic target for ocular BD via its inhibition of Th1 and Th17 cytokines. As the population studied was small and heterogeneous, further studies are needed to confirm the findings

Frequent p53 Accumulation in the Chronically Sun-Exposed Epidermis and Clonal Expansion of p53 Mutant Cells in the Epidermis Adjacent to Basal Cell Carcinoma

p53 expression was studied immunohistochemically to identify a precursor lesion of basal cell carcinoma (BCC) in the epidermis adjacent to BCC. With two different anti-p53 antibodies of CM1 and DO7, p53 expression was frequently detected in the epidermis adjacent to BCCs arising on the face and in the normal epidermis with usual sun exposure. In the epidermis adjacent to BCC, stained cells were occasionally clustered in a small area, but no cluster was found in the normal epidermis with usual sun exposure. The expression was less frequent in the normal epidermis with rare sun exposure. Ten cases of normal skin with usual sun exposure, showing CM1 staining in the epidermis, were screened for p53 gene mutations with polymerase chain reaction-single- strand conformation polymorphism analysis using DNAs obtained from the epidermis. No mutation was detected in exons 2 to 10 of the p53 gene in these 10 cases. The epidermis flanking three BCCs that was stained with CM1, on the other hand, carried a missense mutation of C to G transversIon at a dipyrimidine site of codon 249. This alteration replaced arginine with threonine. The mutation of codon 249 was not detected in the three BCCs. Our results first suggest that ultraviolet light irradiating the skin in a daily life induces p53 accumulation in the epidermis and secondly that the frequent clonal expansion of p53 mutant cells occurs in the epidermis adjacent to BCCs. This clonal expansion of mutant p53 may provide a molecular basis for high risk of developing subsequent new skin cancers in patients with BCC

Significance of adrenomedullin under cardiopulmonary bypass in children during surgery for congenital heart disease.

To elucidate the effect of adrenomedullin (AM) on fluid homeostasis under cardiopulmonary bypass (CPB), we investigated the serial changes in plasma AM and other parameters related to fluid homeostasis in 13 children (average age, 28.2 months) with congenital heart disease during cardiac surgery under CPB. Arterial blood and urine samples were collected just after initiation of anesthesia, just before commencement of CPB, 10 min before the end of CPB, 60 min after CPB, and 24 h after operation. Plasma AM levels increased significantly 10 min before the end of CPB and decreased 24 h after operation. Urine volume increased transiently during CPB, which paralleled changes in AM. Simple regression analysis showed that plasma AM level correlated significantly with urinary vasopressin, urine volume, urinary sodium excretion, and plasma osmolarity. Stepwise regression analysis indicated that urine volume was the most significant determinant of plasma AM levels. Percent rise in AM during CPB relative to control period correlated with that of plasma brain natriuretic peptide (r = 0.57, P &#60; 0.01). Our results suggest that AM plays an important role in fluid homeostasis under CPB in cooperation with other hormones involved in fluid homeostasis.</p

Mass-Metallicity Relation for the Local Group Dwarf Spheroidal Galaxies: A New Picture for the Chemical Enrichment of Galaxies in the Lowest Mass Range

The virial mass ($M_{\rm vir}$)-metallicity relation among the Local Group dwarf spheroidal galaxies (dSphs) is examined. Hirashita, Takeuchi, & Tamura showed that the dSphs can be divided into two distinct classes with respect to the relation between their virial masses and luminosities: low-mass (M_{\rm vir} \la 10^8 M_\odot) and high-mass (M_{\rm vir} \ga 10^8 M_\odot) groups. We see that both the mass-metallicity and the mass-luminosity relations of the high-mass dSphs are understood as a low-mass extension of giant ellipticals. On the contrary, we find that the classical galactic-wind model is problematic to apply to the low-mass dSphs, whose low binding energy is comparable to that released by several supernova explosions. A strongly regulated star formation in their formation phase is required to reproduce their observed metallicity. Such regulation is naturally expected in a gas cloud with the primordial elemental abundance according to Nishi & Tashiro. A significant scatter in the mass-metallicity relation for the low-mass dSphs is also successfully explained along with the scenario of Hirashita and coworkers. We not only propose a new picture for a chemical enrichment of the dSphs, but also suggest that the mass-metallicity and the mass-luminosity relations be understood in a consistent context.Comment: 14 pages LaTeX, 1 PostScript figure, to appear in ApJ Lette

A Highly Advanced Gastric Cancer Maintaining a Clinical Complete Response after Chemoradiotherapy Comprising S-1 and Cisplatin

We report a patient with highly advanced gastric carcinoma who was treated successfully with chemoradiotherapy (CRT) comprising S-1 and cisplatin. The patient was a 71-year-old male who was diagnosed with advanced gastric carcinoma by esophagogastroduodenoscopy (EGD) by medical examination. EGD demonstrated type 3 advanced gastric carcinoma in the posterior wall of the upper gastric body. An abdominal computed tomography (CT) scan showed that the gastric wall was thickened due to gastric primary tumor, and large lymph nodes (LNs) including the lesser curvature LN, anterosuperior LN along the common hepatic artery and some para-aortic LNs were detected. The patient was diagnosed with stage IV advanced gastric carcinoma according to the Japanese classification of gastric carcinoma (cT4a, cN3, cM1 [para-aortic LN], cStage IV). Preoperative CRT was carried out in an attempt to downstage the disease. Remarkable reduction of the primary tumor and metastatic LNs was observed after initial CRT, and radiological examination determined that a partial response had been achieved. Adverse effects included grade 2 anorexia and grade 3 ALP elevation (919 U/ml). No grade 4 or more severe adverse event was observed. After CRT, although we recommended curative surgery, the patient refused surgical treatment and opted for conservative treatment. Thus, we continued S-1 oral administration for 1 year. Five months after beginning CRT, upper endoscopy showed that the tumor had maintained regression and scar formation, in which no cancer cells were detected by endoscopic biopsy. The patient is doing well and has maintained a clinical complete response for more than 42 months without curative surgery. CRT could be considered as an option for treatment of patients with locally advanced gastric carcinoma diagnosed as unresectable, or for those who refuse surgical treatment