219 research outputs found
The trajectory of counterfactual simulation in development
Young children often struggle to answer the question “what would have happened?” particularly in cases where the adult-like “correct” answer has the same outcome as the event that actually occurred. Previous work has assumed that children fail because they cannot engage in accurate counterfactual simulations. Children have trouble considering what to change and what to keep fixed when comparing counterfactual alternatives to reality. However, most developmental studies on counterfactual reasoning have relied on binary yes/no responses to counterfactual questions about complex narratives and so have only been able to document when these failures occur but not why and how. Here, we investigate counterfactual reasoning in a domain in which specific counterfactual possibilities are very concrete: simple collision interactions. In Experiment 1, we show that 5- to 10-year-old children (recruited from schools and museums in Connecticut) succeed in making predictions but struggle to answer binary counterfactual questions. In Experiment 2, we use a multiple-choice method to allow children to select a specific counterfactual possibility. We find evidence that 4- to 6-year-old children (recruited online from across the United States) do conduct counterfactual simulations, but the counterfactual possibilities younger children consider differ from adult-like reasoning in systematic ways. Experiment 3 provides further evidence that young children engage in simulation rather than using a simpler visual matching strategy. Together, these experiments show that the developmental changes in counterfactual reasoning are not simply a matter of whether children engage in counterfactual simulation but also how they do so. (PsycInfo Database Record (c) 2021 APA, all rights reserved
HEPA/Vaccine Plan for Indoor Anthrax Remediation
A mathematical model suggests that a HEPA/vaccine approach is viable for most buildings after a large-scale anthrax attack
Building a collaborative Psychological Science: Lessons Learned from ManyBabies 1
The field of infancy research faces a difficult challenge: Some questions require samples that are simply too large for any 1 lab to recruit and test. ManyBabies aims to address this problem by forming large-scale collaborations on key theoretical questions in developmental science, while promoting the uptake of Open Science practices. Here, we look back on the first project completed under the ManyBabies umbrella—ManyBabies 1—which tested the development of infant-directed speech preference. Our goal is to share the lessons learned over the course of the project and to articulate our vision for the role of large-scale collaborations in the field. First, we consider the decisions made in scaling up experimental research for a collaboration involving 100+ researchers and 70+ labs. Next, we discuss successes and challenges over the course of the project, including the following: protocol design and implementation, data analysis, organisational structures and collaborative workflows, securing funding, and encouraging broad participation in the project. Finally, we discuss the benefits we see both in ongoing ManyBabies projects and in future large-scale collaborations in general, with a particular eye toward developing best practices and increasing growth and diversity in infancy research and psychological science in general. Throughout the article, we include first-hand narrative experiences to illustrate the perspectives of researchers playing different roles within the project. Although this project focused on the unique challenges of infant research, many of the insights we gained can be applied to large-scale collaborations across the broader field of psychology
Staphylococcus aureus enterotoxin b down-regulates the expression of transforming growth factor-beta (TGF-β) signaling transducers in human glioblastoma
Background: It has been revealed that Staphylococcus aureus enterotoxin B (SEB) may feature anti-cancer and anti-metastatic advantages due to its ability to modify cell immunity processes and signaling pathways. Glioblastoma is one of the most aggressive human cancers; it has a high mortality nature, which makes it an attractive area for the development of novel therapies. Objectives: We examined whether the SEB could exert its growth inhibitory effects on glioblastoma cells partially through the manipulation of a key tumor growth factor termed transforming growth factor-beta (TGF-β). Materials and Methods: A human primary glioblastoma cell line, U87, was treated with different concentrations of SEB. The cell quantity was measured by the MTT assay at different exposure times. For molecular assessments, total ribonucleic acid (RNA) was extracted from either non-treated or SEB-treated cells. Subsequently, the gene expression of TGF-β transducers, smad2/3, at the messenger RNA (mRNA) level, was analyzed via a quantitative real-time polymerase chain reaction (qPCR) using the SYBR Green method. Significant differences between cell viability and gene expression levels were determined (Prism 5.0 software) using a one-way analysis of variance (ANOVA) test. Results: We reported that SEB could effectively down-regulate smad2/3 expression in glioblastoma cells at concentrations as quantity as 1 µg/mL and 2 µg/mL (P < 0.05 and P < 0.01, respectively). The SEB concentrations effective at regulating smad2/3 expression were correlated with those used to inhibit the proliferation of glioblastoma cells. Our results also showed that SEB was able to decrease smad2/3 expression at the mRNA level in a concentration- and time-dependent manner. Conclusions: We suggested that SEB could represent an agent that can significantly decrease smad2/3 expression in glioblastoma cells, leading to moderate TGF-β growth signaling and the reduction of tumor cell proliferation. © 2016, Ahvaz Jundishapur University of Medical Sciences
The claudin gene family: expression in normal and neoplastic tissues
BACKGROUND: The claudin (CLDN) genes encode a family of proteins important in tight junction formation and function. Recently, it has become apparent that CLDN gene expression is frequently altered in several human cancers. However, the exact patterns of CLDN expression in various cancers is unknown, as only a limited number of CLDN genes have been investigated in a few tumors. METHODS: We identified all the human CLDN genes from Genbank and we used the large public SAGE database to ascertain the gene expression of all 21 CLDN in 266 normal and neoplastic tissues. Using real-time RT-PCR, we also surveyed a subset of 13 CLDN genes in 24 normal and 24 neoplastic tissues. RESULTS: We show that claudins represent a family of highly related proteins, with claudin-16, and -23 being the most different from the others. From in silico analysis and RT-PCR data, we find that most claudin genes appear decreased in cancer, while CLDN3, CLDN4, and CLDN7 are elevated in several malignancies such as those originating from the pancreas, bladder, thyroid, fallopian tubes, ovary, stomach, colon, breast, uterus, and the prostate. Interestingly, CLDN5 is highly expressed in vascular endothelial cells, providing a possible target for antiangiogenic therapy. CLDN18 might represent a biomarker for gastric cancer. CONCLUSION: Our study confirms previously known CLDN gene expression patterns and identifies new ones, which may have applications in the detection, prognosis and therapy of several human cancers. In particular we identify several malignancies that express CLDN3 and CLDN4. These cancers may represent ideal candidates for a novel therapy being developed based on CPE, a toxin that specifically binds claudin-3 and claudin-4
G2A Signaling Dampens Colitic Inflammation via Production of IFN-γ
Proinflammatory consequences have been described for lysophosphatidylcholine, a lipid product of cellular injury, signaling via the
G protein–coupled receptor G2A on myeloid and lymphoid inflammatory cells. This prompted the hypothesis that genetic deletion
of G2A would limit intestinal inflammation in a mouse model of colitis induced by dextran sodium sulfate. Surprisingly, G2A2/2
mice exhibited significantly worsened colitis compared with wild-type mice, as demonstrated by disease activity, colon shortening,
histology, and elevated IL-6 and IL-5 in colon tissues. Investigation of inflammatory cells recruited to inflamed G2A2/2 colons
showed significantly more TNF-a+ and Ly6ChiMHCII2 proinflammatory monocytes and eosinophils than in wild-type colons.
Both monocytes and eosinophils were pathogenic as their depletion abolished the excess inflammation in G2A2/2 mice. G2A2/2
mice also had less IFN-g in inflamed colon tissues than wild-type mice. Fewer CD4+ lymphocytes were recruited to inflamed
G2A2/2 colons, and fewer colonic lymphocytes produced IFN-g upon ex vivo stimulation. Administration of IFN-g to G2A2/2
mice during dextran sodium sulfate exposure abolished the excess colitic inflammation and reduced colonic IL-5 and eosinophil
numbers to levels seen in wild-type mice. Furthermore, IFN-g reduced the numbers of TNF-a+ monocyte and enhanced their
maturation from Ly6ChiMHCII2 to Ly6CintMHCII+
. Taken together, the data suggest that G2A signaling serves to dampen
intestinal inflammation via the production of IFN-g, which, in turn, enhances monocyte maturation to a less inflammatory
program and ultimately reduces eosinophil-induced injury of colonic tissues
Appetite Suppression and Altered Food Preferences Coincide with Changes in Appetite-Mediating Hormones During Energy Deficit at High Altitude, But Are Not Affected by Protein Intake
Appetite suppression and altered food preferences coincide with changes in appetite-mediating hormones during energy deficit at high altitude, but are not affected by protein intake. High Alt Med Biol. 19:156–169, 2018.—Anorexia and unintentional body weight loss are common during high altitude (HA) sojourn, but underlying mechanisms are not fully characterized, and the impact of dietary macronutrient composition on appetite regulation at HA is unknown. This study aimed to determine the effects of a hypocaloric higher protein diet on perceived appetite and food preferences during HA sojourn and to examine longitudinal changes in perceived appetite, appetite mediating hormones, and food preferences during acclimatization and weight loss at HA. Following a 21-day level (SL) period, 17 unacclimatized males ascended to and resided at HA (4300 m) for 22 days. At HA, participants were randomized to consume measured standard-protein (1.0 g protein/kg/d) or higher protein (2.0 g/kg/d) hypocaloric diets (45% carbohydrate, 30% energy restriction) and engaged in prescribed physical activity to induce an estimated 40% energy deficit. Appetite, food preferences, and appetite-mediating hormones were measured at SL and at the beginning and end of HA. Diet composition had no effect on any outcome. Relative to SL, appetite was lower during acute HA (days 0 and 1), but not different after acclimatization and weight loss (HA day 18), and food preferences indicated an increased preference for sweet- and low-protein foods during acute HA, but for high-fat foods after acclimatization and weight loss. Insulin, leptin, and cholecystokinin concentrations were elevated during acute HA, but not after acclimatization and weight loss, whereas acylated ghrelin concentrations were suppressed throughout HA. Findings suggest that appetite suppression and altered food preferences coincide with changes in appetite-mediating hormones during energy deficit at HA. Although dietary protein intake did not impact appetite, the possible incongruence with food preferences at HA warrants consideration when developing nutritional strategies for HA sojourn
IFN-γ Rα Is a Key Determinant of CD8+ T Cell-Mediated Tumor Elimination or Tumor Escape and Relapse in FVB Mouse
During the past decade, the dual function of the immune system in tumor inhibition and tumor progression has become appreciated. We have previously reported that neu-specific T cells can induce rejection of neu positive mouse mammary carcinoma (MMC) and also facilitate tumor relapse by inducing neu antigen loss and epithelial to mesenchymal transition (EMT). Here, we sought to determine the mechanism by which CD8+ T cells either eliminate the tumor, or maintain tumor cells in a dormant state and eventually facilitate tumor relapse. We show that tumor cells that express high levels of IFN-γ Rα are eliminated by CD8+ T cells. In contrast, tumor cells that express low levels of IFN-γ Rα do not die but remain dormant and quiescent in the presence of IFN-γ producing CD8+ T cells until they hide themselves from the adaptive immune system by losing the tumor antigen, neu. Relapsed tumor cells show CD44+CD24- phenotype with higher rates of tumorigenesis, in vivo. Acquisition of CD44+CD24- phenotype in relapsed tumors was not solely due to Darwinian selection. Our data suggest that tumor cells control the outcome of tumor immune surveillance through modulation of the expression of IFN-γ Rα
Claudin 7 expression and localization in the normal murine mammary gland and murine mammary tumors
INTRODUCTION: Claudins, membrane-associated tetraspanin proteins, are normally associated with the tight junctions of epithelial cells where they confer a variety of permeability properties to the transepithelial barrier. One member of this family, claudin 7, has been shown to be expressed in the human mammary epithelium and some breast tumors. To set the stage for functional experiments on this molecule, we examined the developmental expression and localization of claudin 7 in the murine mammary epithelium and in a selection of murine mammary tumors. METHOD: We used real-time polymerase chain reaction, in situ mRNA localization, and immunohistochemistry (IHC) to examine the expression and localization of claudin 7. Frozen sections were examined by digital confocal microscopy for colocalization with the tight-junction protein ZO1. RESULTS: Claudin 7 was expressed constitutively in the mammary epithelium at all developmental stages, and the ratio of its mRNA to that of keratin 19 was nearly constant through development. By IHC, claudin 7 was located in the basolateral part of the cell where it seemed to be localized to discrete vesicles. Scant colocalization with the tight-junction scaffolding protein ZO1 was observed. Similar results were obtained from IHC of the airway epithelium and some renal tubules; however, claudin 7 did partly colocalize with ZO1 in EPH4 cells, a normal murine mammary cell line, and in the epididymis. The molecule was localized in the cytoplasm of MMTV-neu and the transplantable murine tumor cell lines TM4, TM10, and TM40A, in which its ratio to cytokeratin was higher than in the normal mammary epithelium. CONCLUSION: Claudin 7 is expressed constitutively in the mammary epithelium at approximately equal levels throughout development as well as in the murine tumors examined. Although it is capable of localizing to tight junctions, in the epithelia of mammary gland, airway, and kidney it is mostly or entirely confined to punctate cytoplasmic structures, often near the basolateral surfaces of the cells and possibly associated with basolateral membranes. These observations suggest that claudin 7 might be involved in vesicle trafficking to the basolateral membrane, possibly stabilizing cytoplasmic vesicles or participating in cell–matrix interactions
Claudin-1, -3 and -4 proteins and mRNA expression in benign and malignant breast lesions: a research study
INTRODUCTION: We compared levels of protein and mRNA expression of three members of the claudin (CLDN) family in malignant breast tumours and benign lesions. METHODS: Altogether, 56 sections from 52 surgically resected breast specimens were analyzed for CLDN1, CLDN3 and CLDN4 expression by immunohistochemistry. mRNA was also analyzed using real-time PCR in 17 of the 52 cases. RESULTS: CLDNs were rarely observed exclusively at tight junction structures. CLDN1 was present in the membrane of normal duct cells and in some of the cell membranes from ductal carcinoma in situ, and was frequently observed in eight out of nine areas of apocrine metaplasia, whereas invasive tumours were negative for CLDN1 or it was present in a scattered distribution among such tumour cells (in 36/39 malignant tumours). CLDN3 was present in 49 of the 56 sections and CLDN4 was present in all 56 tissue sections. However, CLDN4 was highly positive in normal epithelial cells and was decreased or absent in 17 out of 21 ductal carcinoma grade 1, in special types of breast carcinoma (mucinous, papillary, tubular) and in areas of apocrine metaplasia. CLDN1 mRNA was downregulated by 12-fold in the sample (tumour) group as compared with the control group using GAPDH as the reference gene. CLDN3 and CLDN4 mRNA exhibited no difference in expression between invasive tumours and surrounding tissue. CONCLUSIONS: The significant loss of CLDN1 protein in breast cancer cells suggests that CLDN1 may play a role in invasion and metastasis. The loss of CLDN4 expression in areas of apocrine metaplasia and in the majority of grade 1 invasive carcinomas also suggests a particular role for this protein in mammary glandular cell differentiation and carcinogenesis
- …