Selective knockout of gold active sites

It has long been known that defects on a gold surface play an important role in electrocatalysis, but the precise mechanism has always been unclear. This work indicates that the defect sites provide partially filled d-orbitals that stabilize freeradical intermediates. Strong evidence for this hypothesis is that the sites can be selectively knocked out by treatment with OH• radicals generated by Fenton's reagent. The knockout effect is demonstrated using oxygen reduction, hydrogen reduction, and the redox electrochemistry of hydroquinone

Stem cells migration during skeletal muscle regeneration - the role of Sdf-1/Cxcr4 and Sdf-1/ Cxcr7 axis

The skeletal muscle regeneration occurs due to the presence of tissue specific stem cells - satellite cells. These cells, localized between sarcolemma and basal lamina, are bound to muscle fibers and remain quiescent until their activation upon muscle injury. Due to pathological conditions, such as extensive injury or dystrophy, skeletal muscle regeneration is diminished. Among the therapies aiming to ameliorate skeletal muscle diseases are transplantations of the stem cells. In our previous studies we showed that Sdf-1 (stromal derived factor ¡1) increased migration of stem cells and their fusion with myoblasts in vitro. Importantly, we identified that Sdf-1 caused an increase in the expression of tetraspanin CD9 - adhesion protein involved in myoblasts fusion. In the current study we aimed to uncover the details of molecular mechanism of Sdf-1 action. We focused at the Sdf-1 receptors - Cxcr4 and Cxcr7, as well as signaling pathways induced by these molecules in primary myoblasts, as well as various stem cells - mesenchymal stem cells and embryonic stem cells, i.e. the cells of different migration and myogenic potential. We showed that Sdf-1 altered actin organization via FAK (focal adhesion kinase), Cdc42 (cell division control protein 42), and Rac-1 (Ras- Related C3 Botulinum Toxin Substrate 1). Moreover, we showed that Sdf-1 modified the transcription profile of genes encoding factors engaged in cells adhesion and migration. As the result, cells such as primary myoblasts or embryonic stem cells, became characterized by more effective migration when transplanted into regenerating muscle

Associations of preschoolers’ dietary patterns with eating behaviors and parental feeding practices at a 12-month follow-up of obesity treatment

Although dietary patterns are key to the management of childhood obesity, they are rarely assessed and thus poorly understood. This study examines preschoolers' dietary patterns and correlates 12 months after the start of obesity treatment (n = 99, mean age 5.2 years, 52% girls). A food frequency questionnaire (FFQ), the Child Eating Behavior Questionnaire (CEBQ), Child Feeding Questionnaire (CFQ) and Lifestyle Behavior Checklist (LBC) were answered by parents to assess children's food intake, eating behaviors, parental feeding practices, and obesity-related behaviors, respectively. Principal component analysis identified dietary patterns based on FFQ data. Through multiple linear regressions we examined correlations between a healthy (HD) and a less healthy (LHD) dietary pattern and mean scores of the CEBQ, CFQ, LBC scales as well as BMI z-scores. The reported intake of items in the LHD decreased after treatment while no differences were found for the HD. Children's eating behaviors, in particular food fussiness, showed consistent associations with diet (b = −0.39, 95% CI −0.63, −0.14 for HD and b = 0.41, 95% CI 0.15, 0.66 for LHD). Feeding practices and obesity-related behaviours were weakly associated with the dietary patterns (HD and Monitoring: b = 0.36, 95% CI 0.09, 0.62; LHD and Screen time b = 0.08, 95% CI 0.01, 0.15). Among the measured variables, eating behaviors had the largest impact on children's dietary patterns. The LHD was associated with a higher BMI z-score but no associations were found between changes in LHD intake and changes in BMI z-scores. Our findings suggest that decreasing food fussiness in children with obesity is key to positive dietary changes. Assessment of children's eating behaviors can help tailor dietary advice and provide support for families of children with obesity

Myogenic Differentiation of Mouse Embryonic Stem Cells That Lack a Functional Pax7 Gene

The transcription factor Pax7 plays a key role during embryonic myogenesis and sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Overexpression of Pax7 has been shown to promote the myogenic differentiation of pluripotent stem cells. However, the effects of the absence of functional Pax7 in differentiating embryonic stem cells (ESCs) have not yet been directly tested. Herein, we studied mouse stem cells that lacked a functional Pax7 gene and characterized the differentiation of these stem cells under conditions that promoted the derivation of myoblasts in vitro. We analyzed the expression of myogenic factors, such as myogenic regulatory factors and muscle-specific microRNAs, in wild-type and mutant cells. Finally, we compared the transcriptome of both types of cells and did not find substantial differences in the expression of genes related to the regulation of myogenesis. As a result, we showed that the absence of functional Pax7 does not prevent the in vitro myogenic differentiation of ESCs

Parenting and childhood obesity : validation of a new questionnaire and evaluation of treatment effects during the preschool years

Objectives Parenting is an integral component of obesity treatment in early childhood. However, the link between specific parenting practices and treatment effectiveness remains unclear. This paper introduces and validates a new parenting questionnaire and evaluates mothers’ and fathers’ parenting practices in relation to child weight status during a 12-month childhood obesity treatment trial. Methods First, a merged school/clinical sample (n = 558, 82% mothers) was used for the factorial and construct validation of the new parenting questionnaire. Second, changes in parenting were evaluated using clinical data from the More and Less Study, a randomized controlled trial (RCT) with 174 children (mean age = 5 years, mean Body Mass Index Standard Deviation Score (BMI SDS) = 3.0) comparing a parent support program (with and without booster sessions) and standard treatment. Data were collected at four time points over 12 months. We used linear mixed models and mediation models to investigate associations between changes in parenting practices and treatment effects. Findings The validation of the questionnaire (9 items; responses on a 5-point Likert scale) revealed two dimensions of parenting (Cronbach’s alpha ≥0.7): setting limits to the child and regulating one’s own emotions when interacting with the child, both of which correlated with feeding practices and parental self-efficacy. We administered the questionnaire to the RCT participants. Fathers in standard treatment increased their emotional regulation compared to fathers in the parenting program (p = 0.03). Mothers increased their limit-setting regardless of treatment allocation (p = 0.01). No treatment effect was found on child weight status through changes in parenting practices. Conclusion Taken together, the findings demonstrate that the new questionnaire assessing parenting practices proved valid in a 12-month childhood obesity trial. During treatment, paternal and maternal parenting practices followed different trajectories, though they did not mediate treatment effects on child weight status. Future research should address the pathways whereby maternal and paternal parenting practices affect treatment outcomes, such as child eating behaviors and weight status

The miR151 and miR5100 Transfected Bone Marrow Stromal Cells Increase Myoblast Fusion in IGFBP2 Dependent Manner

BACKGROUND: Bone marrow stromal cells (BMSCs) form a perivascular cell population in the bone marrow. These cells do not present naïve myogenic potential. However, their myogenic identity could be induced experimentally in vitro or in vivo. In vivo, after transplantation into injured muscle, BMSCs rarely fused with myofibers. However, BMSC participation in myofiber reconstruction increased if they were modified by NICD or PAX3 overexpression. Nevertheless, BMSCs paracrine function could play a positive role in skeletal muscle regeneration. Previously, we showed that SDF-1 treatment and coculture with myofibers increased BMSC ability to reconstruct myofibers. We also noticed that SDF-1 treatment changed selected miRNAs expression, including miR151 and miR5100. METHODS: Mouse BMSCs were transfected with miR151 and miR5100 mimics and their proliferation, myogenic differentiation, and fusion with myoblasts were analyzed. RESULTS: We showed that miR151 and miR5100 played an important role in the regulation of BMSC proliferation and migration. Moreover, the presence of miR151 and miR5100 transfected BMSCs in co-cultures with human myoblasts increased their fusion. This effect was achieved in an IGFBP2 dependent manner. CONCLUSIONS: Mouse BMSCs did not present naïve myogenic potential but secreted proteins could impact myogenic cell differentiation. miR151 and miR5100 transfection changed BMSC migration and IGFBP2 and MMP12 expression in BMSCs. miR151 and miR5100 transfected BMSCs increased myoblast fusion in vitro. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12015-022-10350-y

Cell cycle regulation of embryonic stem cells and mouse embryonic fibroblasts lacking functional Pax7

The transcription factor Pax7 plays a key role during embryonic myogenesis and in adult organisms in that it sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Recently we have shown that lack of Pax7 does not prevent the myogenic differentiation of pluripotent stem cells. In the current work we show that the absence of functional Pax7 in differentiating embryonic stem cells modulates cell cycle facilitating their proliferation. Surprisingly, deregulation of Pax7 function also positively impacts at the proliferation of mouse embryonic fibroblasts. Such phenotypes seem to be executed by modulating the expression of positive cell cycle regulators, such as cyclin E

We Do Not Like It: A Likert-Type Scale Survey on the Attitudes of a Young Population towards the Transhumanistic Theory of Education

Transhumanists assume that future education may be purely based on technological stimulation. The question is: Do potential clients of education “like” such vision? In order to check this, we asked over one thousand two hundred young Poles to evaluate their identification with the transhumanistic theory of education. The results are quite surprising: its show that they disagree with the assumptions of this theory, while they rather agree with the postulates of more traditional (and no technology-based) concepts of education