293 research outputs found

    Assessing Signal-Driven Mechanisms in Neonates: Brain Responses to Temporally and Spectrally Different Sounds

    Get PDF
    Past studies have found that, in adults, the acoustic properties of sound signals (such as fast versus slow temporal features) differentially activate the left and right hemispheres, and some have hypothesized that left-lateralization for speech processing may follow from left-lateralization to rapidly changing signals. Here, we tested whether newborns’ brains show some evidence of signal-specific lateralization responses using near-infrared spectroscopy (NIRS) and auditory stimuli that elicits lateralized responses in adults, composed of segments that vary in duration and spectral diversity. We found significantly greater bilateral responses of oxygenated hemoglobin (oxy-Hb) in the temporal areas for stimuli with a minimum segment duration of 21 ms, than stimuli with a minimum segment duration of 667 ms. However, we found no evidence for hemispheric asymmetries dependent on the stimulus characteristics. We hypothesize that acoustic-based functional brain asymmetries may develop throughout early infancy, and discuss their possible relationship with brain asymmetries for language

    Functional Lateralization of Speech Processing in Adults and Children Who Stutter

    Get PDF
    Developmental stuttering is a speech disorder in fluency characterized by repetitions, prolongations, and silent blocks, especially in the initial parts of utterances. Although their symptoms are motor related, people who stutter show abnormal patterns of cerebral hemispheric dominance in both anterior and posterior language areas. It is unknown whether the abnormal functional lateralization in the posterior language area starts during childhood or emerges as a consequence of many years of stuttering. In order to address this issue, we measured the lateralization of hemodynamic responses in the auditory cortex during auditory speech processing in adults and children who stutter, including preschoolers, with near-infrared spectroscopy. We used the analysis–resynthesis technique to prepare two types of stimuli: (i) a phonemic contrast embedded in Japanese spoken words (/itta/ vs. /itte/) and (ii) a prosodic contrast (/itta/ vs. /itta?/). In the baseline blocks, only /itta/ tokens were presented. In phonemic contrast blocks, /itta/ and /itte/ tokens were presented pseudo-randomly, and /itta/ and /itta?/ tokens in prosodic contrast blocks. In adults and children who do not stutter, there was a clear left-hemispheric advantage for the phonemic contrast compared to the prosodic contrast. Adults and children who stutter, however, showed no significant difference between the two stimulus conditions. A subject-by-subject analysis revealed that not a single subject who stutters showed a left advantage in the phonemic contrast over the prosodic contrast condition. These results indicate that the functional lateralization for auditory speech processing is in disarray among those who stutter, even at preschool age. These results shed light on the neural pathophysiology of developmental stuttering

    Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa

    Get PDF
    Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities

    Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa

    Get PDF
    Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities

    An online database of infant functional near infraRed spectroscopy studies: a community-augmented systematic review

    Get PDF
    Until recently, imaging the infant brain was very challenging. Functional Near InfraRed Spectroscopy (fNIRS) is a promising, relatively novel technique, whose use is rapidly expanding. As an emergent field, it is particularly important to share methodological knowledge to ensure replicable and robust results. In this paper, we present a community-augmented database which will facilitate precisely this exchange. We tabulated articles and theses reporting empirical fNIRS research carried out on infants below three years of age along several methodological variables. The resulting spreadsheet has been uploaded in a format allowing individuals to continue adding new results, and download the most recent version of the table. Thus, this database is ideal to carry out systematic reviews. We illustrate its academic utility by focusing on the factors affecting three key variables: infant attrition, the reliability of oxygenated and deoxygenated responses, and signal-to-noise ratios. We then discuss strengths and weaknesses of the DBIfNIRS, and conclude by suggesting a set of simple guidelines aimed to facilitate methodological convergence through the standardization of reports

    Goal representation in the infant brain

    Get PDF
    It is well established that, from an early age, human infants interpret the movements of others as actions directed towards goals. However, the cognitive and neural mechanisms which underlie this ability are hotly debated. The current study was designed to identify brain regions involved in the representation of others’ goals early in development. Studies with adults have demonstrated that the anterior intraparietal sulcus (aIPS) exhibits repetition suppression for repeated goals and a release from suppression for new goals, implicating this specific region in goal representation in adults. In the current study, we used a modified paired repetition suppression design with 9-month-old infants to identify which cortical regions are suppressed when the infant observes a repeated goal versus a new goal. We find a strikingly similar response pattern and location of activity as had been reported in adults; the only brain region displaying significant repetition suppression for repeated goals and a release from suppression for new goals was the left anterior parietal region. Not only does our data suggest that the left anterior parietal region is specialized for representing the goals of others’ actions from early in life, this demonstration presents an opportunity to use this method and design to elucidate the debate over the mechanisms and cues which contribute to early action understanding

    Effect of Luseogliflozin on Heart Failure With Preserved Ejection Fraction in Patients With Diabetes Mellitus

    Get PDF
    Background Effects of sodium‐glucose cotransporter 2 inhibitors on reducing hospitalization for heart failure have been reported in randomized controlled trials, but their effects on patients with heart failure with preserved ejection fraction (HFpEF) are unknown. This study aimed to evaluate the drug efficacy of luseogliflozin, a sodium‐glucose cotransporter 2 inhibitor, in patients with type 2 diabetes mellitus and HFpEF. Methods and Results We performed a multicenter, open‐label, randomized, controlled trial for comparing luseogliflozin 2.5 mg once daily with voglibose 0.2 mg 3 times daily in patients with type 2 diabetes mellitus suffering from HFpEF (left ventricular ejection fraction >45% and BNP [B‐type natriuretic peptide] concentrations ≥35 pg/mL) in a 1:1 randomization fashion. The primary outcome was the difference from baseline in BNP levels after 12 weeks of treatment between the 2 drugs. A total of 173 patients with diabetes mellitus and HFpEF were included. Of these, 83 patients were assigned to receive luseogliflozin and 82 to receive voglibose. There was no significant difference in the reduction in BNP concentrations after 12 weeks from baseline between the 2 groups. The ratio of the mean BNP value at week 12 to the baseline value was 0.79 in the luseogliflozin group and 0.87 in the voglibose group (percent change, −9.0% versus −1.9%; ratio of change with luseogliflozin versus voglibose, 0.93; 95% CI, 0.78–1.10; P=0.26). Conclusion In patients with type 2 diabetes mellitus and HFpEF, there is no significant difference in the degree of reduction in BNP concentrations after 12 weeks between luseogliflozin and voglibose

    Effects of luseogliflozin and voglibose on high-risk lipid profiles and inflammatory markers in diabetes patients with heart failure

    Get PDF
    Sodium-glucose cotransporter 2 inhibitors could reduce cardiovascular events in patients with heart failure irrespective of diabetes status. In this prespecified sub-analysis of randomised-controlled trial, we investigated the efficacy of luseogliflozin (2.5 mg daily), a sodium-glucose cotransporter 2 inhibitor, with that of voglibose (0.6 mg daily), an alpha-glucosidase inhibitor, on high-risk lipid profile and inflammatory markers in patients with type-2 diabetes and heart failure. Among the 157 patients studied, there were no significant differences in the mean malondialdehyde LDL or small-dense LDL cholesterol levels between the luseogliflozin and voglibose groups (percent change: 0.2% vs. - 0.6%, p = 0.93; - 1.7% vs. - 8.6%, p= 0.21) after 12 weeks in comparison to levels at the baseline. No significant difference was observed between the two groups in the adiponectin and high-sensitivity C-reactive protein levels after 12 weeks compared to the baseline levels (percent change, - 1.6% vs. - 4.0% and 22.5% vs. 10.0%; p = 0.52 and p = 0.55, respectively). In conclusion, in patients with type-2 diabetes and heart failure, compared to voglibose, luseogliflozin did not significantly improve the high-risk lipoprotein profile including malondialdehyde LDL and small-dense LDL cholesterol or the levels of inflammatory markers, including adiponectin and high-sensitivity C-reactive protein

    Optimization of the proliferation and persistency of CAR T cells derived from human induced pluripotent stem cells

    Get PDF
    CARシグナルを補完する遺伝子改変により *iCAR-T細胞の固形がん治療効果が改善される. 京都大学プレスリリース. 2022-12-13.Genetic modifications boosting CAR signaling improve the therapeutic efficacy of iPSC-derived CAR-T cells against solid tumors. 京都大学プレスリリース. 2022-12-13.The effectiveness of chimaeric antigen receptor (CAR) T-cell immunotherapies against solid tumours relies on the accumulation, proliferation and persistency of T cells at the tumour site. Here we show that the proliferation of CD8αβ cytotoxic CAR T cells in solid tumours can be enhanced by deriving and expanding them from a single human induced-pluripotent-stem-cell clone bearing a CAR selected for efficient differentiation. We also show that the proliferation and persistency of the effector cells in the tumours can be further enhanced by genetically knocking out diacylglycerol kinase, which inhibits antigen-receptor signalling, and by transducing the cells with genes encoding for membrane-bound interleukin-15 (IL-15) and its receptor subunit IL-15Rα. In multiple tumour-bearing animal models, the engineered hiPSC-derived CAR T cells led to therapeutic outcomes similar to those of primary CD8 T cells bearing the same CAR. The optimization of effector CAR T cells derived from pluripotent stem cells may aid the development of long-lasting antigen-specific T-cell immunotherapies for the treatment of solid tumours

    A clinically applicable and scalable method to regenerate T-cells from iPSCs for off-the-shelf T-cell immunotherapy

    Get PDF
    動物由来の成分を含まないより安全な製法でiPS細胞から大量の再生T細胞を培養する方法の開発 --T細胞を使ったがん免疫療法での利用も--. 京都大学プレスリリース. 2021-01-18.Clinical successes demonstrated by chimeric antigen receptor T-cell immunotherapy have facilitated further development of T-cell immunotherapy against wide variety of diseases. One approach is the development of “off-the-shelf” T-cell sources. Technologies to generate T-cells from pluripotent stem cells (PSCs) may offer platforms to produce “off-the-shelf” and synthetic allogeneic T-cells. However, low differentiation efficiency and poor scalability of current methods may compromise their utilities. Here we show improved differentiation efficiency of T-cells from induced PSCs (iPSCs) derived from an antigen-specific cytotoxic T-cell clone, or from T-cell receptor (TCR)-transduced iPSCs, as starting materials. We additionally describe feeder-free differentiation culture systems that span from iPSC maintenance to T-cell proliferation phases, enabling large-scale regenerated T-cell production. Moreover, simultaneous addition of SDF1α and a p38 inhibitor during T-cell differentiation enhances T-cell commitment. The regenerated T-cells show TCR-dependent functions in vitro and are capable of in vivo anti-tumor activity. This system provides a platform to generate a large number of regenerated T-cells for clinical application and investigate human T-cell differentiation and biology
    corecore