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The purpose of this study was to identify special education teachers' profiles in relation to their levels of burnout, work engagement and job satisfaction, following a person- oriented approach. This approach was chosen in order to provide cfombinations of attributes that shape high-risk groups of low engagement and high burnout. Additionally, it was examined whether these profiles differed with regard to special education teachers' individual parameters and work-related characteristics, such as age, gender, marital status, number of children in family, level of education, region of employment and teaching experience. The sample included 664 in-service special education teachers (503 females and 161 males) working in primary and secondary schools. Two-step cluster analysis yielded four profiles, entitled: passionate, workaholic, operational and overworked. Differences were also noted among profiles, in terms of participants' age, educational level, region and teaching experience. Findings are discussed with reference to implications for future research in order to early detect and support teachers at risk. [ABSTRACT FROM AUTHOR]

While open and distance education gains growing recognition over time, it also faces increasing drop-out rates. Consequently, the development of predictive models for early identification of students at-risk for drop-out could be critical to promote ongoing engagement. This study aims to gain insights into the dropout prediction problem in a sample of postgraduate special education students. Therefore, a nonlinear state-space model was employed. An Expectation-Maximization (EM) algorithm that iterates between state estimation (E-step) and parameter estimation (M-step) was retrieved from the existing literature. However, the variables were redefined according to available data. In the dataset a total number of n1 = 1337 students were enrolled, attending n2 = 7 different modules. Statistical analysis showed that the majority of the students dropped out during the second week. Moreover, an inversely proportional relationship was observed between the dropout rates and the number of weeks that the student has actively engaged in the module. Significant differences across modules were also observed. Results are discussed in terms of their application in the training and education of the collaborating teaching staff working in the HOU. Future work in the field should be expanded in order to investigate students' drop-out in more courses other than special education. [ABSTRACT FROM AUTHOR]

Exploring individual differences and looking beyond averaged parameters of early numeracy in young children with mild intellectual disabilities has become an area of interest to many researchers worldwide. This study aimed to identify the different profiles of early numeracy skills in young children with mild intellectual disabilities. For this purpose, we assessed early numeracy through Utrecht early numeracy test and learning aptitude through Detroit Test, in a sample of 135 children diagnosed with intellectual disabilities. The mean of their mental age was 5:09 (years:months). Two-step cluster analysis identified four homogenous groups of children with distinct early numeracy profiles as follows:C1 were fluent in relational and numerical skills up to 20, C2 were fluent in relational skills and numerical skills up to 10, C3 had basic knowledge of relational skills and inconsistent numerical skills up to 10 and C4 had inconsistent relational skills and numerical skills. Results are discussed with reference to their educational implications. [ABSTRACT FROM AUTHOR]

Mitochondrial calcium (mCa2+) uptake occurs via the Mitochondrial Ca2+ Uniporter (MCU) complex and plays a critical role in mitochondrial dynamics, mitophagy, and apoptosis. MCU complex activity is in part modulated by the expression of its regulatory subunits. Cardiovascular disease models demonstrated altered gene/protein expression of one or multiple subunits in different cells, including vascular endothelial cells (ECs). MCU complex activity was found necessary for stable flow (s‐flow)‐induced mitophagy and promotion of an atheroprotective EC phenotype. Disturbed flow (d‐flow) is known to lead to an atheroprone phenotype. Despite the role of MCU in flow‐regulated EC function, flow‐induced alterations in MCU complex subunit expression are currently unknown. We exposed cultured human ECs to atheroprotective (steady shear stress, SS) or atheroprone flow (oscillatory shear stress, OS) and measured mRNA and protein levels of the MCU complex members. SS and OS differentially modulated subunit expression at gene/protein levels. Protein expression changes of the core MCU, mCa2+ uptake 1 (MICU1) and MCU regulator 1 (MCUR1) subunits in SS‐ and OS‐exposed, compared to static, ECs suggested an enhanced mCa2+ influx under each flow and a potential contribution to EC dysfunction under OS. In silico analysis of a single‐cell RNA‐sequencing dataset was employed to extract transcript values of MCU subunits in mouse carotid ECs from regions exposed to s‐flow or d‐flow. Mcu and Mcur1 genes showed significant differences in expression after prolonged exposure to each flow. The differential expression of MCU complex subunits indicated a tight regulation of the complex activity under physiological and pathological hemodynamic conditions. [ABSTRACT FROM AUTHOR]

The mitochondrial calcium (Ca2+) uniporter (MCU) channel is responsible for mitochondrial Ca2+ influx. Its expression was found to be upregulated in endothelial cells (ECs) under cardiovascular disease conditions. Since the role of MCU in regulating cytosolic Ca2+ homeostasis in ECs exposed to shear stress (SS) is unknown, we studied mitochondrial Ca2+ dynamics (that is known to decode cytosolic Ca2+ signaling) in sheared ECs. To understand cause-and-effect, we ectopically expressed MCU in ECs. A higher percentage of MCU-transduced ECs exhibited mitochondrial Ca2+ transients/oscillations, and at higher frequency, under SS compared to sheared control ECs. Transients/oscillations correlated with mitochondrial reactive oxygen species (mROS) flashes and mitochondrial membrane potential (ΔΨm) flickers, and depended on activation of the mechanosensitive Piezo1 channel and the endothelial nitric oxide synthase (eNOS). A positive feedback loop composed of mitochondrial Ca2+ uptake/mROS flashes/ΔΨm flickers and endoplasmic reticulum Ca2+ release, in association with Piezo1 and eNOS, provided insights into the mechanism by which SS, under conditions of high MCU activity, may shape vascular EC energetics and function. [ABSTRACT FROM AUTHOR]

The purpose of this research was to measure teachers and students interpersonal competences in situations that a teacher may face at school and which require interpersonal interaction with students, parents or other teachers. In addition, the mediating role of interpersonal competences was examined in the relationship between teachers' interpersonal style and burnout. In order to measure interpersonal competences, a test (Teachers' Interpersonal Competency Test) was constructed according to the standards of Situational Judgement Tests (SJTs). The sample consisted of 269 Greek General and Special Education teachers and 117 students from General and Special Education Departments. Participants completed the Teachers' Interpersonal Competency Test, the Questionnaire on Teacher Interaction and the Maslach Burnout Inventory. According to the results of the statistical analysis, interpersonal competences were mainly differentiated between teachers who worked at different levels of education. Differences in interpersonal competences also occurred between teachers and students, as well as between first- and third-year students. Interpersonal competences have been shown to play a protective mediating role between interpersonal style and burnout. The present research contributes to the study of teachers' interpersonal competences and their importance to the wellbeing of teachers and students as well, through the development of supportive interpersonal styles. [ABSTRACT FROM AUTHOR]

In the present study, the role of interpersonal coping strategies was examined in relation to teachers' characteristics and burnout factors. Two hundred sixty-nine General and Special Education teachers completed the Teachers' Interpersonal Competences Test and the Maslach Burnout Inventory. Differences in the use of interpersonal coping strategies were noted on teachers' gender, teaching experience, grade level, experience and training in Special Education. Interpersonal coping strategies predicted most of teachers' burnout factors according to regression analyses. The importance of developing strategies that enhance interpersonal relationships and reduce conflicts at schools, in order to reduce teachers' burnout, is discussed. [ABSTRACT FROM AUTHOR]

Calcium (Ca2+) signaling is critical for cell function and cell survival. Mitochondria play a major role in regulating the intracellular Ca2+ concentration ([Ca2+]i). Mitochondrial Ca2+ uptake is an important determinant of cell fate and governs respiration, mitophagy/autophagy, and the mitochondrial pathway of apoptosis. Mitochondrial Ca2+ uptake occurs via the mitochondrial Ca2+ uniporter (MCU) complex. This review summarizes the present knowledge on the function of MCU complex, regulation of MCU channel, and the role of MCU in Ca2+ homeostasis and human disease pathogenesis. The channel core consists of four MCU subunits and essential MCU regulators (EMRE). Regulatory proteins that interact with them include mitochondrial Ca2+ uptake 1/2 (MICU1/2), MCU dominant-negative b-subunit (MCUb), MCU regulator 1 (MCUR1), and solute carrier 25A23 (SLC25A23). In addition to these proteins, cardiolipin, a mitochondrial membrane-specific phospholipid, has been shown to interact with the channel core. The dynamic interplay between the core and regulatory proteins modulates MCU channel activity after sensing local changes in [Ca2+]i, reactive oxygen species, and other environmental factors. Here, we highlight the structural details of the human MCU heteromeric assemblies and their known roles in regulating mitochondrial Ca2+ homeostasis. MCU dysfunction has been shown to alter mitochondrial Ca2+ dynamics, in turn eliciting cell apoptosis. Changes in mitochondrial Ca2+ uptake have been implicated in pathological conditions affecting multiple organs, including the heart, skeletal muscle, and brain. However, our structural and functional knowledge of this vital protein complex remains incomplete, and understanding the precise role for MCU-mediated mitochondrial Ca2+ signaling in disease requires further research efforts. [ABSTRACT FROM AUTHOR]

Monocyte recruitment and fate specification after myocardial infarction. Am J Physiol Cell Physiol 319: C797-C806, 2020. First published September 2, 2020; doi:10.1152/ ajpcell.00330.2020.--Monocytes are critical mediators of the inflammatory response following myocardial infarction (MI) and ischemia-reperfusion injury. They are involved in both initiation and resolution of inflammation and play an integral role in cardiac repair. The antagonistic nature of their function is dependent on their subset heterogeneity and biphasic response following injury. New advancements in single-cell transcriptomics and mass cytometry have allowed us to identify smaller, transcriptionally distinct clusters that may have functional relevance in disease and homeostasis. Additionally, recent insights into the spatiotemporal dynamics of monocytes following ischemic injury and their subsequent interactions with the endothelium and other immune cells reveal a complex interplay between monocytes and the cardiac milieu. In this review, we highlight recent findings on monocyte functional heterogeneity, present new mechanistic insight into monocyte recruitment and fate specification following MI, and discuss promising therapeutic avenues targeting monocytes for the treatment of ischemic heart disease. [ABSTRACT FROM AUTHOR]

The article discusses the role of age in the relationship between pre-transplant blood transfusion and outcomes for pediatric patients undergoing heart transplantation. Emphasis is given to topics such as mortality hazards for infants and young children, evaluation of patient survival, and aspects of care which include use of left ventricular assist device bridge to transplant.

Teachers' interpersonal style is a new field of research in the study of students with intellectual disabilities and challenging behaviors in school context. In the present study, we investigate emotions and causal attributions of three basic types of challenging behaviors: aggression, stereotypy, and self-injury, in relation to teachers' interpersonal style. One hundred and seventy seven Greek general and special educator teachers participated in the study by completing a three-scaled questionnaire. Statistical analysis revealed that the type of challenging behaviors affected causal attributions. According to regression analysis, emotions, teaching experience, expertise in special education, and gender explained a significant amount of variance in interpersonal style. Emotions were found to have a mediating role in the relationship between causal attributions and interpersonal style of "willingness to support," when challenging behaviors were attributed to stable causes or causes under the control of the individual with intellectual disabilities. [ABSTRACT FROM AUTHOR]

Shear stress is known to stimulate an intracellular free calcium concentration ([Ca2+]i) response in vascular endothelial cells (ECs). [Ca2+]i is a key second messenger for signaling that leads to vasodilation and EC survival. Although it is accepted that the shear-induced [Ca2+]i response is, in part, due to Ca2+ release from the endoplasmic reticulum (ER), the role of mitochondria (second largest Ca2+ store) is unknown. We hypothesized that the mitochondria play a role in regulating [Ca2+]i in sheared ECs. Cultured ECs, loaded with a Ca2+-sensitive fluorophore, were exposed to physiological levels of shear stress. Shear stress elicited [Ca2+]i transients in a percentage of cells with a fraction of them displaying oscillations. Peak magnitudes, percentage of oscillating ECs, and oscillation frequencies depended on the shear level. [Ca2+]i transients/oscillations were present when experiments were conducted in Ca2+-free solution (plus lanthanum) but absent when ECs were treated with a phospholipase C inhibitor, suggesting that the ER inositol 1,4,5-trisphosphate receptor is responsible for the [Ca2+]i response. Either a mitochondrial uncoupler or an electron transport chain inhibitor, but not a mitochondrial ATP synthase inhibitor, prevented the occurrence of transients and especially inhibited the oscillations. Knockdown of the mitochondrial Ca2+ uniporter also inhibited the shear-induced [Ca2+]i transients/oscillations compared with controls. Hence, EC mitochondria, through Ca2+ uptake/release, regulate the temporal profile of shear-induced ER Ca2+ release. [Ca2+]i oscillation frequencies detected were within the range for activation of mechanoresponsive kinases and transcription factors, suggesting that dysfunctional EC mitochondria may contribute to cardiovascular disease by deregulating the shear-induced [Ca2+]i response. [ABSTRACT FROM AUTHOR]

Contrary to the growing body of research into views about and attitudes towards disability which has focused on the perspectives of non-disabled people, recent disability studies have been directed to the voices of people with disabilities and/or their families, by acknowledging an ‘epistemic privilege’ to them. In the present study, we use the posts of sensory and physical disability groups on Facebook as a lens to uncover the voices and experiences of people with disabilities and/or their families. The critical discourse analysis of the posts of disability groups on Facebook suggests that people with disabilities and/or their families do not constitute a homogeneous group of people being connected because of their common (bodily) condition. On the other hand, different representations of disability also suggest a different use of Facebook. [ABSTRACT FROM PUBLISHER]

Written language is a difficult endeavour as the demands of transcription require self-regulatory skills from a motor, cognitive and attention perspective. The purpose of the present study was to investigate the relation between the Test of Writing Difficulties (Porpodas et al., 2007) and the Test of Detection and Investigation of Executive Functions (Simos et al., 2007) in a sample of 50 Greek-speaking, 5th-grade students with writing disabilities. The results of our study indicated that there were significant Pearson correlations ranging from .35 to .44 between executive functions and written expression. Furthermore, regression analysis showed that the subscales of the Test of Executive Functions had significant predictive power for spelling correctness and correction of jumbled sentences. Further implications of these findings for a school-based neuropsychological evaluation and planning of individualised educational interventions are discussed. [ABSTRACT FROM PUBLISHER]

Perceptual-motor deficits are common in children with intellectual disabilities and have a profound impact on their ability to perform age-appropriate self-care and academic tasks. The purpose of the present study was to investigate the relation between the Beery Test of Visual-Motor Integration (VMI) (Beery 1989) and the Wechsler Intelligence Scale for Children-III (WISC-III) (Georgas, Paraskevopoulos, Bezevegis, and Giannitsas 1997) in a sample of 40 children with mild intellectual disability. The results in our study indicated that there were significant Pearson correlations ranged from.39 to.52 between the VMI and the WISC-III, showing higher correlations between the WISC-III Performance IQ and the VMI. Finally, regression analysis was applied to evaluate the relation of the WISC-III scores to the VMI scores. It seems that certain Wechsler scales have predictive power to VMI performance. Correlations between the VMI and measures of intelligence and academic achievement are at best moderate; thus, its use for important decisions such as obtaining needed services and evaluating the effectiveness of educational interventions is unwarranted. [ABSTRACT FROM AUTHOR]

Endothelial cell dysfunction is the hallmark of every cardiovascular disease/condition, including atherosclerosis and ischemia/reperfusion injury. Fluid shear stress acting on the vascular endothelium is known to regulate cell homeostasis. Altered hemodynamics is thought to play a causative role in endothelial dysfunction. The dysfunction is associated with/preceded by mitochondrial oxidative stress. Studies by our group and others have shown that the form and/or function of the mitochondrial network are affected when endothelial cells are exposed to shear stress in the absence or presence of additional physico-chemical stimuli. The present review will summarize the current knowledge on the interconnections among intracellular Ca-nitric oxide-mitochondrial reactive oxygen species, mitochondrial fusion/fission, autophagy/mitophagy, and cell apoptosis vs. survival. More specifically, it will list the evidence on potential regulation of the above intracellular species and processes by the fluid shear stress acting on the endothelium under either physiological flow conditions or during reperfusion (following a period of ischemia). Understanding how the local hemodynamics affects mitochondrial physiology and the cell redox state may lead to development of novel therapeutic strategies for prevention or treatment of the endothelial dysfunction and, hence, of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Over the past few years, perceptions about disability – at least at the theoretical level – have been shifted toward a more progressive approach, which stresses the social aspects of the construction of disability (social model) rather than personal limitations, as supported by the traditional disability approach (medical–individual model). Drawing upon the sociosemiotic approach as developed by Kress and van Leeuwen, the present study examines from a comparative perspective the representations about disability and people with disabilities, as emerging from the drawings produced by 4th grade Greek primary school children. The sample consists of two groups of children.Group Adoes not share the same school environment with schoolchildren with special education needs, whilegroup Bshares the same school surroundings with students attending a special education needs School. The comparative analysis of their drawings indicates that children of both groups reproduce the dominant meanings they receive from their direct social environment. [ABSTRACT FROM AUTHOR]

The mitochondrial network is dynamic with conformations that vary between a tubular continuum and a fragmented state. The equilibrium between mitochondrial fusion/fission, as well as the organelle motility, determine network morphology and ultimately mitochondrial/cell function. Network morphology has been linked with the energy state in different cell types. In this study, we examined how bioenergetic factors affect mitochondrial dynamics/motility in cultured vascular endothelial cells (ECs). ECs were transduced with mitochondria-targeted green fluorescent protein (mito-GFP) and exposed to inhibitors of oxidative phosphorylation (OXPHOS) or ATP synthesis. Time-lapse fluorescence videos were acquired and a mathematical program that calculates size and speed of each mitochondrial object at each time frame was developed. Our data showed that inner mitochondrial membrane potential (ΔΨ), ATP produced by glycolysis, and, to a lesser degree, ATP produced by mitochondria are critical for maintaining the mitochondrial network, and different metabolic stresses induce distinct morphological patterns (e.g., mitochondrial depolarization is necessary for 'donut' formation). Mitochondrial movement, characterized by Brownian diffusion with occasional bursts in displacement magnitude, was inhibited under the same conditions that resulted in increased fission. Hence, imaging/mathematical analysis shed light on the relationship between bioenergetics and mitochondrial network morphology; the latter may determine EC survival under metabolic stress. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum - Gas University of Ploiesti Bulletin, Educational Sciences Series is the property of Petroleum - Gas University of Ploiesti and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum - Gas University of Ploiesti Bulletin, Educational Sciences Series is the property of Petroleum - Gas University of Ploiesti and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An important pedestrian skill that young people with intellectual disabilities (ID) (mental retardation) find difficult is the ability to find a safe place to cross the road. Safe pedestrian behaviour relies on cognitive skills, including the ability to focus attention on the traffic environment and ignore irrelevant stimuli. Individuals with ID consistently demonstrate selective attention deficiencies. Other factors such as individual differences in cognitive style might play a role in road safety. The aims of the present study were to test any possible significant relationship between attention, cognitive style and identification of safe and dangerous road-crossing sites in preadolescents with ID. Participants were 40 boys with mild ID. Attention and field dependence-independence were assessed using the visual attention subtest of the Developmental Neuropsychological Assessment and the Children's Embedded Figures Test (CEFT), respectively. The participants were subdivided into two groups, matched on IQ. The two groups differed significantly in mean score on the visual attention subtest and on the CEFT. Analysis of variance showed that preadolescents with higher scores on both tests performed better than those who were more filed dependent and less attentive. Attention and cognitive style should be considered in the planning of road safety training for individuals with ID. [ABSTRACT FROM AUTHOR]

Klinefelter syndrome (KS) is a genetic disorder in males characterized by the presence of an extra X chromosome. Its most consistent endocrinological manifestations include lower testosterone production and impaired spermatogenesis. KS individuals have a general typical appearance with taller stature, and they demonstrate a characteristic cognitive phenotype involving weaknesses in verbal processing. Anomalous cerebral lateralization involves the inverse or weak dominance of hand, language, and visuospatial abilities and has been associated with the cognitive deficits of KS individuals. This article summarizes the ongoing research in this field, discusses the main findings, and attempts to provide a thorough description of the cause of the observed functional and anatomical cerebral asymmetries associated with the syndrome. Nonetheless, efforts have been directed to incorporate evidence for and against theoretical accounts that explain the experimental findings, to discuss issues involving the implications of the chosen methodology, and present key research areas for future empirical research. [ABSTRACT FROM AUTHOR]

The main disability associated with DS is a cognitive deficit which is thought to influence children's ability to perceive process and make use of relevant information to solve problems and engage in appropriate behaviour (Carr, 1985). For a significant number of children with DS, the acquisition of motor skills is also difficult. Their rate of motor development tends to be slower than that of children who develop typically and their movements are often less coordinated and efficient (Block, 1991). The association between atypical laterality and DS has been reported several times (Groen et al, 2007). Moreover, researchers have indicated that factors like cerebral asymmetry and/or ageing, reading habits influence directionality and performance on tasks including directionality trends in whole-body movements. The present study investigates: a) DS children's directionality trends in writing and drawing, b) their innate directional tendencies in whole body movements. Forty-eight children (24 DS and 24 typically developing children) participated in this research. All participants were between the age of 8 and 13 years and right-handed as assessed by the Briggs and Nebes (1975) Handedness Scale, without any major physical and/or motor disabilities. The children were asked first to copy specific verbal and non-verbal graphic patterns and then to perform some predefined movements, so that their preferable directionality and point of initiation could be recorded. The experimental groups demonstrated significant differences mostly in whole body movement directionality (p>.001), only in some non- verbal graphic patterns (p<.05) and their initial point (p<.05). The discussion focuses on the strong impact of schooling and writing instructions in directionality trends and also on deficiency in cerebral asymmetry of DS children. Finally, the necessity for further research in perceptuo-motor relationships of DS children's with the education and motor development is suggested. [ABSTRACT FROM AUTHOR]

The present study provides insight into the strategies utilized by bilingual students while reading texts in a foreign language. Thirty three bilingual students of 4th, 5th and 6th elementary school grades, learning English as a foreign language, participated in the study. The study employed a qualitative approach of data collection and analysis using student interviews and think-aloud reports to investigate the range of reading strategies employed, as well as to understand bilingual students' reading sub- processes. The results indicated that there was a clear developmental pattern: Older readers were becoming more efficient in using a combination of cognitive and metacognitive strategies for constructing meaning than younger ones. In addition, poor bilingual readers employed a wider range of reading strategies and followed a top - down reading process compared to poor ones who employed basically 'bottom-up' strategies and had limited awareness of their reading comprehension. The results of the study accord with previous ones highlighting the importance of strategy identification and suggesting for strategy instruction to help bilingual students become more successful readers. [ABSTRACT FROM AUTHOR]

Cultured vascular endothelial cell (EC) exposure to steady laminar shear stress results in peroxynitrite (ONOO-) formation intramitochondrially and inactivation of the electron transport chain. We examined whether the "hyperoxic state" of 21% O2, compared with more physiological O2 tensions (PO2), increases the shear-induced nitric oxide (NO) synthesis and mitochondrial superoxide (O2.-) generation leading to ONOO- formation and suppression of respiration. Electron paramagnetic resonance oximetry was used to measure O2 consumption rates of bovine aortic ECs sheared (10 dyn/cm², 30 min) at 5%, 10%, or 21% O2 or left static at 5% or 21% O2. Respiration was inhibited to a greater extent when ECs were sheared at 21% O2 than at lower PO2 or left static at different PO2. Flow in the presence of an endothelial NO synthase (eNOS) inhibitor or a ONOO- scavenger abolished the inhibitory effect. EC transfection with an adenovirus that expresses manganese superoxide dismutase in mitochondria, and not a control virus, blocked the inhibitory effect. Intracellular and mitochondrial O2.- production was higher in ECs sheared at 21% than at 5% O2, as determined by dihydroethidium and MitoSOX red fluorescence, respectively, and the latter was, at least in part, NO-dependent. Accumulation of NO metabolites in media of ECs sheared at 21% O2 was modestly increased compared with ECs sheared at lower PO2, suggesting that eNOS activity may be higher at 21% O2. Hence, the hyperoxia of in vitro EC flow studies, via increased NO and mitochondrial O2.- production, leads to enhanced ONOO- formation intramitochondrially and suppression of respiration. [ABSTRACT FROM AUTHOR]

There is evidence that nitric oxide (NO), superoxide (O2·-), and their associated reactive nitrogen species (RNS) produced by vascular endothelial cells (ECs) in response to hemodynamic forces play a role in cell signaling. NO is known to impair mitochondrial respiration. We sought to determine whether exposure of human umbilical vein ECs (HUVECs) to steady laminar shear stress and the resultant NO production modulate electron transport chain (ETC) enzymatic activities. The activities of respiratory complexes I, II/III, and IV were dependent on the presence of serum and growth factor supplement in the medium. EC exposure to steady laminar shear stress (10 dyn/cm²) resulted in a gradual inhibition of each of the complexes starting as early as 5 mm from the flow onset and lasting up to 16 h. Ramp flow resulted in inhibition of the complexes similar to that of step flow. When ECs were sheared in the presence of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 100 µM), the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazolmne-1-oxyl-3-oxide (c-PTIO; 100 µM), or the peroxynitrite (ONOO-) scavenger uric acid (UA; 50 µM), the flow-inhibitory effect on mitochondrial complexes was attenuated. In particular, L-NAME and UA abolished the flow effect on complex IV. Increased tyrosine nitration was observed in the mitochondria of sheared ECs, and UA blocked the shear-induced nitrotyrosine staining. In summary, shear stress induces mitochondrial RNS formation that inhibits the electron flux of the ETC at multiple sites. This may be a critical mechanism by which shear stress modulates EC signaling and function. [ABSTRACT FROM AUTHOR]

Williams (WS) and Down syndromes (DS) are two genetic disorders that involve intellectual disability (ID) and have been extensively studied over the past decades because of the unique linguistic profiles they exhibit. Recent investigations seek to explore the fractionation of linguistic components within the cognitive system using genetically based neurodevelopmental disorders such as WS and DS and to identify different profiles of linguistic function in these two groups of individuals.The‘expressive vocabulary’,‘receptive vocabulary’,‘word opposites’ and‘word definitions’ subtests (Level 1) of the Test of Word Knowledge (TOWK) were used to assess lexical skills in six children with WS and five children with DS.Our findings indicate that the two syndromes exhibit substantial differences on linguistic tasks with individuals with WS performing at a higher level compared to those with DS and producing atypical responses in word definitions. The pattern of errors for each syndrome is qualitatively different suggesting that their underlying linguistic mechanisms are distinctive even though ID is similar.This study supports the differential outcome of two chromosomal disorders with similar ID. It also argues in favour of the large within group variability of the two syndromes that is not related to mental age but rather to different underlying mechanisms supporting language. These findings are discussed in the light of the current evidence concerning linguistic knowledge of neurodevelopmental and genetic disorders. [ABSTRACT FROM AUTHOR]

Antibody-mediated rejection is characterized by deposits of complement (C) C4 and C3 split products on endothelial cells (ECs). C3 split products are critical mechanistically and diagnostically because they are deposited in amplified quantities, bind covalently to ECs and act as ligands for leukocytes. This study was designed to determine whether cultured vascular human ECs could clear covalently bound C3 split products from their surface. An immunoglobulin M (IgM) antibody against β2-microglobulin of major histocompatibility complex class I antigens was used to activate C in human serum. Some cells were exposed to hypoxia/reoxygenation and/or interleukin 1 β (IL-1 β) prior to incubation with antibody. C3b/iC3b and C3d deposition on the cell surface was measured by flow cytometry. Incubation with antibody followed by human serum caused a dose-dependent deposition of C3b/iC3b and C3d. Over half of deposited C3b/iC3b and one-third of C3d were cleared from the cell surface during a 3–7-h incubation period with human serum. Neither hypoxia/reoxygenation nor IL-1 β further increased the deposition of C3b/iC3b and C3d, and only slightly modulated their rates of clearance. In summary, human ECs rapidly clear iC3b and C3d from their surface. This finding may have important diagnostic and mechanistic implications to transplantation because C3d is used as a marker of antibody-mediated rejection. [ABSTRACT FROM AUTHOR]

Adhesion of platelets to the exposed extracellular matrix proteins at sites of vascular injury is partly regulated by the local fluid shear stress. Because the Leu33Pro (PlA) polymorphism of integrin β3 confers only a modest increase in adhesion under static conditions, we used CHO and 293 cells expressing the Leu33 or Pro33 isoform of β3 in flow chamber experiments to test whether shear forces would alter the PlA adhesive phenotype. We found that shear force augmented the Pro33-mediated enhanced adhesion to fibrinogen. This Pro33-dependent enhancement was aspirin-sensitive and was also observed on immobilized von Willebrand factor and cryoprecipitate, but not fibronectin. Thus, shear stress enhances the adhesive phenotype of the Pro33 cells to multiple physiologic substrates. [Copyright &y& Elsevier]

Focuses on the factors influencing the adhesion of flowing monocytes to hypoxia-reoxygenation-exposed endothelial cells. Importance of reactive oxygen species production on tissue injury; Processes involved in the expression of inflammatory genes; Molecular mechanisms regulating adhesive interactions.

Laminar shear stress activates NADPH oxidase in vascular endothelial cells (ECs), and the generated superoxide radicals (O[sub 2] [sup –] ·) are known to be involved in intercellular adhesion molecule (ICAM)-1 expression. In this study, the role of a glycosphingolipid (GSL), lactosylceramide (LacCer), as a second messenger in the shear-induced O[sub 2] [sup –] · generation and ICAM-1 expression was examined. It is known that glucosylceramide synthase (GlcT-1) catalyzes the synthesis of glucosylceramide (GlcCer) from ceramide, and subsequently lactosylceramide synthase (GalT-2) synthesizes LacCer from GlcCer. We observed that exposing cultured human umbilical vein ECs (HUVECs) to fluid shear stress (20 dyn/cm[sup 2] for 30 min) activated GalT-2. Shear stress also increased EC O[sub 2] [sup –] · generation, that peaked at 30 min, and surface ICAM-1 protein expression at 6 h post-shear. EC preincubation with the antioxidant N-acetylcysteine (NAC; 20 mM for 2 h) completely abolished the shear-induced O[sub 2] [sup –] · production and significantly inhibited ICAM-1 expression. EC preincubation with D-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of the GSL glycosyltransferases GlcT-1 and GalT-2, abrogated the shear-induced activation of GalT-2. D-PDMP also abolished the shear-induced O[sub 2] [sup –] · production and ICAM-1 expression. We conclude that laminar shear stress activates GalT-2 to produce LacCer. In turn, LacCer activates NADPH oxidase, which produces O[sub 2] [sup –] ·, and O[sub 2] [sup –] · mediates the shear-induced increase in ICAM-1 expression. Thus, LacCer may play an important role in hemodynamic force-induced pathological conditions, such as atherosclerosis and ischemia/reperfusion injury.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

ABSTRACT. The Test of Nonverbal Intelligence (TONI-2; L. Brown, R. J. Sherbenou, & S. Johnsen, 1990) and Raven's Colored Progressive Matrices (RCPM; J. C. Raven, 1965) are defined as language-free measures of cognitive ability. The purpose of the present study was to investigate the relation between the RCPM and the TONI-2 for samples of patients with Parkinson's disease (n = 75) and controls (n = 47). A regression equation was computed to evaluate the relation of the RCPM scores to the TONI-2 quotient. Regression equation results indicate that there is a significant overlapping linear variance between the two measures in both patients and controls. [ABSTRACT FROM AUTHOR]

The Parkinson's disease questionnaire (PDQ-39) is a well-validated British scale for the assessment of health-related quality of life (HQoL) in Parkinson's disease (PD). The PDQ-39 has been translated into Greek and it was applied to 119 Greek PD patients. These patients were classified in stages according to the Hoehn and Yahr (HY) scale and their motor disability was assessed by means of the Unified Parkinson's disease rating scale (UPDRS) as well as the Schwab and England activities of daily living scale (ADL). The Beck depression inventory (BDI) was applied for the evaluation of depression. The translated version of PDQ-39, designated PDQ-39GrV, was validated as follows: (1) Cronbach's alpha coefficient and item-total Spearman's rank-order correlations were calculated in order to estimate the internal consistency of PDQ-39GrV scales. (2) Validity of the PDQ-39GrV was examined in terms of agreement with the clinical assessment parameters (stage, UPDRS. ADL and BDI scores). (3) Sixty one PD patients were re-evaluated 3-7 days later in order to check test-retest reliability. The results showed the following: (1) The PDQ-39GrV demonstrated very good internal consistency (alpha 0.71-0.94). Item-total correlations were statistically significant (r: 0.52-0.93). Test-retest measurements correlated significantly (p = 0.001). (2) Clinically obtained motor parameters correlated well with PDQ-39GrV scales influenced by physical aspects of the disease, while emotionally and socially influenced ones correlated with depression. Our findings indicate that PDQ-39 GrV is a reliable, easy to administer scale for the assessment of HQoL in Greek PD patients. [ABSTRACT FROM AUTHOR]

Abstract: This study compared the weight-discrimination sensitivity of 41 congenitally blind and 41 normally sighted adults. The superior weight-discrimination sensitivity of the congenitally blind subjects suggests that blindness from birth can cause compensatory adaptations within the cutaneous modality. [ABSTRACT FROM AUTHOR]

Evaluates the performance of nondemented patients with Parkinson's Disease on the Wisconsin Card Sorting Test in all variables in relationship to clinical parameters of the disease. Clinical assessment of symptoms of patients by means of the Unified Parkinson's Disease Rating Scale; Patients' inability to maintain set as the most important deficit in the test scores.

An in vitro whole blood reperfusion model was employed to quantify: (a) initial rates of lysis of mural platelet deposits from flowing blood onto fibrin-coated surfaces and (b) plasmin-mediated consumption of plasma plasminogen and fibrinogen, by recombinant tissue-type plasminogen activator (rt-PA) and two t-PA variants, KHRR 296–299 AAAA (K-tPA) and T103N, N117Q, KHRR 296–299 AAAA (TNK-tPA), at wall shear rates of either 500 or 1000 s−1. K- and TNK-tPA are more fibrin-specific than rt-PA, and are also resistant to inactivation by plasminogen activator inhibitor−1 (PAI−1). At 500 s−1, no agent showed significant lysis of mural platelet deposits on fibrin, even at concentrations as high as 10 μ g/ml of blood. At 1000 s−1, each agent demonstrated a dose-dependent lysis of mural platelet deposits, due to plasmin-mediated lysis of the fibrin substrate (fibrinolysis). The local concentration of thrombolytic agents close to the fibrin-coated surface is probably higher than the concentration of released PAI−1 from the adherent and activated platelets. Hence, the initial rates of lysis achieved by K- and TNK-tPA were not significantly different from that by rt-PA, when each agent was tested at either 1 or 10 μ g/ml of blood. However, TNK-tPA, at 1 μ g/ml,> caused the most extensive lysis at the end of the 50 min reperfusion period (50% vs 29% and 17% by rt-PA and K-tPA, respectively). K- and TNK-tPA, at concentrations as high as 10 μ g/ml of blood, caused plasminogen activation that was controlled by the natural plasmin inhibitors, and, thus, no proteolytic degradation of plasma fibrinogen (fibrinogenolysis). On the contrary, rt-PA at 1 μ g/ml revealed slight fibrinogenolysis that became extensive at 10 μ g/ml. This study demonstrates the potential use of an in vitro model, that mimics the in vivo hemodynamic environment, in evaluating the performance of thrombolytic agents. The data suggest that: (a) adequate flow must accompany fibrinolysis for successful embolization, and (b) the TNK variant may lyse annular thrombi after recanalization, at least as efficiently as rt-PA does, while causing lesser defect of systemic hemostasis. © 1998 Biomedical Engineering Society. PAC98: 8745Hw, 8790+y, 8380Lz, 8715Kg [ABSTRACT FROM AUTHOR]

Two adjective pairs in comparative form, more-less and taller-shorter, were tested with moderately mentally retarded (MR) and nonretarded children (NR) matched on verbal mental age (MA) and socioeconomic status (SES) in a “show” and an “act-out” experimental condition. The data indicated that all the main effects, the group, the experimental condition, and the unmarked-marked relational terms were significant and so were the interactions of the Group × Experimental Conditions, Group × Unmarked Versus Marked Relational Terms, and Group × Experimental Conditions and Unmarked Versus Marked Relational Terms. A logistic regression analysis (LRA) showed that the relational term shorter in the act-out condition best predicted classification membership for the subjects in either group, suggesting that the MR children were less able to self-regulate behavior. The error types, however, mainly observed in the act-out experimental condition were the same from a semantic point of view in either group. The effect of the unmarked versus marked distinction cannot be considered independent of the experimental conditions applied. [ABSTRACT FROM AUTHOR]

Upon inositol trisphosphate (IP3) stimulation of non-excitable cells, including vascular endothelial cells, calcium (Ca2+) shuttling between the endoplasmic reticulum (ER) and mitochondria, facilitated by complexes called Mitochondria-Associated ER Membranes (MAMs), is known to play an important role in the occurrence of cytosolic Ca2+ concentration ([Ca2+]Cyt) oscillations. A mathematical compartmental closed-cell model of Ca2+ dynamics was developed that accounts for ER-mitochondria Ca2+ microdomains as the µd compartment (besides the cytosol, ER and mitochondria), Ca2+ influx to/efflux from each compartment and Ca2+ buffering. Varying the distribution of functional receptors in MAMs vs. the rest of ER/mitochondrial membranes, a parameter called the channel connectivity coefficient (to the µd), allowed for generation of [Ca2+]Cytoscillations driven by distinct mechanisms at various levels of IP3 stimulation. Oscillations could be initiated by the transient opening of IP3 receptors facing either the cytosol or the µd, and subsequent refilling of the respective compartment by Ca2+ efflux from the ER and/or the mitochondria. Only under conditions where the µd became the oscillation-driving compartment, silencing the Mitochondrial Ca2+ Uniporter led to oscillation inhibition. Thus, the model predicts that alternative mechanisms can yield [Ca2+]Cyt oscillations in non-excitable cells, and, under certain conditions, the ER-mitochondria µd can play a regulatory role. [ABSTRACT FROM AUTHOR]

Seventy-three subjects with mild and moderate intellectual disability (ID) of an unknown/idiopathic nature, who had no record of specific deficits in motor control, and 73 normal controls, matched for chronological age and sex, underwent evaluation of handedness. The results confirmed the previously reported excess of non-right handedness among subjects with ID, and suggested that this finding might be indicative of a deviant cerebral organization or atypical lateralization of cerebral representation of function in this group. However, it was noted that further research is needed to clarify how far this is a function of level of motor skill and how far is a syndrome-specific pathological phenomenon. [ABSTRACT FROM AUTHOR]