497 research outputs found
Long-lasting positive effects of collaborative remembering on false assents to misleading questions
Previous studies showed that collaborative remembering can reduce false memories through a process of mutual error checking, although conclusions were limited by the nature of the memory tasks (very few errors). The present experiments extend these findings to eyewitness memory by using a paradigm designed to increase the frequency of memory errors. Collaborative and nominal pairs viewed a video-clip illustrating a bank robbery, provided an immediate free recall, were forced to confabulate answers to false-event questions, and, after a short- (1 h: Experiment 1) or a long-term delay (1 week: Experiment 2), were administered a yes/no recognition task in which the misleading statements either matched the questions presented in the confabulation phase (answered questions) or not (control questions). Collaborative pairs recalled fewer correct details in the immediate free recall task, replicating the negative effects of collaborative inhibition. Most importantly, in the final recognition test, collaborative pairs were less likely to provide false assents to misleading statements, regardless of whether they had provided a response to the related false-event questions 1 h or 1 week earlier. Our results suggest that collaboration can increase the eyewitnesses' tendency to check the accuracy of others' responses and reject false memories through discussion
Changes in cardiac heparan sulfate proteoglycan expression and streptozotocin-induced diastolic dysfunction in rats
<p>Abstract</p> <p>Background</p> <p>Changes in the proteoglycans glypican and syndecan-4 have been reported in several pathological conditions, but little is known about their expression in the heart during diabetes. The aim of this study was to investigate in vivo heart function changes and alterations in mRNA expression and protein levels of glypican-1 and syndecan-4 in cardiac and skeletal muscles during streptozotocin (STZ)-induced diabetes.</p> <p>Methods</p> <p>Diabetes was induced in male Wistar rats by STZ administration. The rats were assigned to one of the following groups: control (sham injection), after 24 hours, 10 days, or 30 days of STZ administration. Echocardiography was performed in the control and STZ 10-day groups. Western and Northern blots were used to quantify protein and mRNA levels in all groups. Immunohistochemistry was performed in the control and 30-day groups to correlate the observed mRNA changes to the protein expression.</p> <p>Results</p> <p>In vivo cardiac functional analysis performed using echocardiography in the 10-day group showed diastolic dysfunction with alterations in the peak velocity of early (E) diastolic filling and isovolumic relaxation time (IVRT) indices. These functional alterations observed in the STZ 10-day group correlated with the concomitant increase in syndecan-4 and glypican-1 protein expression. Cardiac glypican-1 mRNA and skeletal syndecan-4 mRNA and protein levels increased in the STZ 30-day group. On the other hand, the amount of glypican in skeletal muscle was lower than that in the control group. The same results were obtained from immunohistochemistry analysis.</p> <p>Conclusion</p> <p>Our data suggest that membrane proteoglycans participate in the sequence of events triggered by diabetes and inflicted on cardiac and skeletal muscles.</p
Reduced pancreatic β-cell mass is associated with decreased FoxO1 and Erk1/2 protein phosphorylation in low-protein malnourished rats
A low-protein diet leads to functional and structural pancreatic islet alterations, including islet hypotrophy. Insulin-signaling pathways are involved in several adaptive responses by pancreatic islets. We determined the levels of some insulin-signaling proteins related to pancreatic islet function and growth in malnourished rats. Adult male Wistar rats (N = 20 per group) were fed a 17% protein (normal-protein diet; NP) or 6% protein (low-protein diet; LP), for 8 weeks. At the end of this period, blood glucose and serum insulin and albumin levels were measured. The morphometric parameters of the endocrine pancreas and the content of some proteins in islet lysates were determined. The β-cell mass was significantly reduced (≅65%) in normoglycemic but hypoinsulinemic LP rats compared to NP rats. Associated with these alterations, a significant 30% reduction in insulin receptor substrate-1 and a 70% increase in insulin receptor substrate-2 protein content were observed in LP islets compared to NP islets. The phosphorylated serine-threonine protein kinase (pAkt)/Akt protein ratio was similar in LP and NP islets. The phosphorylated forkhead-O1 (pFoxO1)/FoxO1 protein ratio was decreased by 43% in LP islets compared to NP islets (P < 0.05). Finally, the ratio of phosphorylated-extracellular signal-related kinase 1/2 (pErk1/2) to total Erk1/2 protein levels was decreased by 71% in LP islets compared to NP islets (P < 0.05). Therefore, the reduced β-cell mass observed in LP rats is associated with the reduction of phosphorylation in mitogenic-related signals, FoxO1 and Erk proteins. The cause/effect basis of this association remains to be determined4210935941FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2/04310-4; 04/11684-9; 03/10829-
First report about saxitoxins in freshwater fish Hoplias malabaricus through trophic exposure.
Cyanobacterial waterblooms, such as the saxitoxin (STX) producer Cylindrospermopsis raciborskii, have been a worldwide concern in environmental health. However, the bioaccumulation of this neurotoxin in the trophic chain is not completely known. The aim of the present work was to evaluate STX bioaccumulation through chemical analyses and the toxic and trophic effects using biomarkers in the tropical freshwater fish Hoplias malabaricus. They were fed once every five days with Astyanax sp. before being subjected to intraperitoneal inoculation with STX extract (0.08 mg/100 g) obtained by lysis of toxic C. raciborskii strain (T3). After 20 days the brain was collected for acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH), lipoperoxidation (LPO), protein carbonylation (PCO), and comet assay analysis. The muscle was collected for STX chemical analysis. The activities of SOD and concentrations of PCO and LPO increased. The CAT, GST, and GPx activities decreased. Genotoxicity was observed in the experimental group. STX was not detected in muscle samples. Thus, an oxidative stress was observed in the brain, leading to the damage of lipids, proteins, and DNA. The mechanism of action of the neurotoxin in this subchronic exposure suggests an apoptotic cellular process
Impact of N-tau on adult hippocampal neurogenesis, anxiety, and memory.
Different pathological tau species are involved in memory loss in Alzheimer’s disease, the most common
cause of dementia among older people. However, little is known about how tau pathology directly affects
adult hippocampal neurogenesis, a unique form of structural plasticity implicated in hippocampusdependent
spatial learning and mood-related behavior. To this aim, we generated a transgenic mouse
model conditionally expressing a pathological tau fragment (26e230 aa of the longest human tau isoform,
or N-tau) in nestin-positive stem/progenitor cells. We found that N-tau reduced the proliferation
of progenitor cells in the adult dentate gyrus, reduced cell survival and increased cell death by a caspase-
3eindependent mechanism, and recruited microglia. Although the number of terminally differentiated
neurons was reduced, these showed an increased dendritic arborization and spine density. This resulted
in an increase of anxiety-related behavior and an impairment of episodic-like memory, whereas less
complex forms of spatial learning remained unaltered. Understanding how pathological tau species
directly affect neurogenesis is important for developing potential therapeutic strategies to direct
neurogenic instructive cues for hippocampal function repair
The attentional boost effect in young and adult euthymic bipolar patients and healthy controls
In the Attentional Boost Effect (ABE), stimuli encoded with to-be-responded targets are later recognized more accurately than stimuli encoded with to-be-ignored distractors. While this effect is robust in young adults, evidence regarding healthy older adults and clinical populations is sparse. The present study investigated whether a significant ABE is present in bipolar patients (BP), who, even in the euthymic phase, suffer from attentional deficits, and whether the effect is modulated by age. Young and adult euthymic BP and healthy controls (HC) presented with a sequence of pictures paired with target or distractor squares were asked to pay attention to the pictures and press the spacebar when a target square appeared. After a 15-min interval, their memory of the pictures was tested in a recognition task. The performance in the detection task was lower in BP than in HC, in both age groups. More importantly, neither young nor adult BP exhibited a significant ABE; for HC, a robust ABE was only found in young participants. The results suggest that the increase in the attentional demands of the detection task in BP and in adult HC draws resources away from the encoding of target-associated stimuli, resulting in elimination of the ABE. Clinical implications are discussed
Inserção do cuidado terapêutico na construção do conhecimento da enfermagem
Se trata de una reflexión teórico-filosófica sobre la importancia de la inserción del cuidado terapéutico en la construcción del conocimiento de la enfermería, en cuanto objeto epistemológico y foco de la disciplina. Para ello, abordamos la construcción de este conocimiento, bajo la óptica del cuidado, a partir del contexto histórico de la enfermería y de la inserción del cuidado terapéutico en la práctica asistencial y, por otro lado como la actividad o tarea profesional, bajo la visión del proceso de trabajo de la enfermería. Al direccionar la construcción del conocimiento, teniendo como base el cuidado terapéutico, creemos que es posible promover una acción junto a las personas de modo integral, singular, plural y ecuánime lo que por sí solo favorecerá la consolidación de la disciplina y visibilidad profesional.trabalho tem como objetivo realizar uma reflexão teórico-filosófica acerca da importância da inserção do cuidado terapêutico na construção do conhecimento da enfermagem, enquanto objeto epistemológico e foco da disciplina. Para tanto, abordamos a construção desse conhecimento, sob a ótica do cuidado, a partir do contexto histórico da enfermagem e da inserção do cuidado terapêutico na prática assistencial e, por outro lado, como a atividade ou tarefa profissional, sob a visão do processo de trabalho da enfermagem. Ao direcionar a construção do conhecimento, tendo como base o cuidado terapêutico, acreditamos ser possível promover uma ação junto às pessoas de modo integral, singular, plural e equânime o que por si só favorecerá a consolidação da disciplina e visibilidade profissional
MTOR and STAT3 pathway hyper-activation is associated with elevated interleukin-6 levels in patients with shwachman-diamond syndrome: Further evidence of lymphoid lineage impairment
Shwachman–Diamond syndrome (SDS) is a rare inherited bone marrow failure syndrome, resulting in neutropenia and a risk of myeloid neoplasia. A mutation in a ribosome maturation factor accounts for almost all of the cases. Lymphoid involvement in SDS has not been well characterized. We recently reported that lymphocyte subpopulations are reduced in SDS patients. We have also shown that the mTOR-STAT3 pathway is hyper-activated in SDS myeloid cell populations. Here we show that mTOR-STAT3 signaling is markedly upregulated in the lymphoid compartment of SDS patients. Furthermore, our data reveal elevated IL-6 levels in cellular supernatants obtained from lymphoblasts, bone marrow mononuclear and mesenchymal stromal cells, and plasma samples obtained from a cohort of 10 patients. Of note, everolimus-mediated inhibition of mTOR signaling is associated with basal state of phosphorylated STAT3. Finally, inhibition of mTOR-STAT3 pathway activation leads to normalization of IL-6 expression in SDS cells. Altogether, our data strengthen the hypothesis that SDS affects both lymphoid and myeloid blood compartment and suggest everolimus as a potential therapeutic agent to reduce excessive mTOR-STAT3 activation in SDS
The Dependency of Nematic and Twist-bend Mesophase Formation on Bend Angle
We have prepared and studied a family of cyanobiphenyl dimers with varying linking groups with a view to exploring how molecular structure dictates the stability of the nematic and twist-bend nematic mesophases. Using molecular modelling and 1D (1)H NOESY NMR spectroscopy, we determine the angle between the two aromatic core units for each dimer and find a strong dependency of the stability of both the nematic and twist-bend mesophases upon this angle, thereby satisfying earlier theoretical models
Bedbugs and Infectious Diseases
Bedbugs (Cimex lectularius or Cimex hemipterus) are cosmopolite hematophagus insects, and recent outbreaks have been reported in all major occidental countries. Although they are suspected of transmitting more than 40 infectious agents, no report has yet definitively demonstrated that capacity
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