42 research outputs found

    Human Keratinocyte Growth and Differentiation on Acellular Porcine Dermal Matrix in relation to Wound Healing Potential

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    A number of implantable biomaterials derived from animal tissues are now used in modern surgery. Xe-Derma is a dry, sterile, acellular porcine dermis. It has a remarkable healing effect on burns and other wounds. Our hypothesis was that the natural biological structure of Xe-Derma plays an important role in keratinocyte proliferation and formation of epidermal architecture in vitro as well as in vivo. The bioactivity of Xe-Derma was studied by a cell culture assay. We analyzed growth and differentiation of human keratinocytes cultured in vitro on Xe-Derma, and we compared the results with formation of neoepidermis in the deep dermal wounds treated with Xe-Derma. Keratinocytes cultured on Xe-Derma submerged in the culture medium achieved confluence in 7–10 days. After lifting the cultures to the air-liquid interface, the keratinocytes were stratified and differentiated within one week, forming an epidermis with basal, spinous, granular, and stratum corneum layers. Immunohistochemical detection of high-molecular weight cytokeratins (HMW CKs), CD29, p63, and involucrin confirmed the similarity of organization and differentiation of the cultured epidermal cells to the normal epidermis. The results suggest that the firm natural structure of Xe-Derma stimulates proliferation and differentiation of human primary keratinocytes and by this way improves wound healing

    Weak coupling of neurons enables very high-frequency and ultra-fast oscillations through the interplay of synchronized phase-shifts

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    Recently, in the past decade, high-frequency oscillations (HFOs), very high-frequency oscillations (VHFOs), and ultra-fast oscillations (UFOs) were reported in epileptic patients with drug-resistant epilepsy. However, to this day, the physiological origin of these events has yet to be understood. Our study establishes a mathematical framework based on bifurcation theory for investigating the occurrence of VHFOs and UFOs in depth EEG signals of patients with focal epilepsy, focusing on the potential role of reduced connection strength between neurons in an epileptic focus. We demonstrate that synchronization of a weakly coupled network can generate very and ultra high-frequency signals detectable by nearby microelectrodes. In particular, we show that a bistability region enables the persistence of phase-shift synchronized clusters of neurons. This phenomenon is observed for different hippocampal neuron models, including Morris-Lecar, Destexhe-Paré, and an interneuron model. The mechanism seems to be robust for small coupling, and it also persists with random noise affecting the external current. Our findings suggest that weakened neuronal connections could contribute to the production of oscillations with frequencies above 1000Hz, which could advance our understanding of epilepsy pathology and potentially improve treatment strategies. However, further exploration of various coupling types and complex network models is needed

    Neurocognitive Predictors of Reading Outcomes for Children With Reading Disabilities

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    This study reports on several specific neurocognitive process predictors of reading outcomes for a sample of 278 children with reading disabilities. Three categories of response (i.e., poor, average, and good) were formed via growth curve models of six reading outcomes. Two nested discriminant function analyses were conducted to evaluate the predictive capability of the following models: (a) an intervention and phonological processing model that included intervention group, phonological awareness, and rapid naming and (b) an additive cognitive neuropsychological model that included measures of memory, visual processes, and cognitive or intellectual functioning. Over and above the substantial explanatory power of the base model, the additive model improved classification of poor and good responders. Several of the cognitive and neuropsychological variables predicted degree of reading outcomes, even after controlling for type of intervention, phonological awareness, and rapid naming

    Psychometric Stability of Nationally Normed and Experimental Decoding and Related Measures in Children with Reading Disability

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    Achievement and cognitive tests are used extensively in the diagnosis and educational placement of children with reading disabilities (RD). Moreover, research on scholastic interventions often requires repeat testing and information on practice effects. Little is known, however, about the test–retest and other psychometric properties of many commonly used measures within the beginning reader population, nor are these nationally normed or experimental measures comparatively evaluated. This study examined the test–retest reliability, practice effects, and relations among a number of nationally normed measures of word identification and spelling and experimental measures of achievement and reading-related cognitive processing tests in young children with significant RD. Reliability was adequate for most tests, although lower than might be ideal on a few measures when there was a lengthy test–retest interval or with the reduced behavioral variability that can be seen in groups of beginning readers. Practice effects were minimal. There were strong relations between nationally normed measures of decoding and spelling and their experimental counterparts and with most measures of reading-related cognitive processes. The implications for the use of such tests in treatment studies that focus on beginning readers are discussed

    Multiple component remediation of developmental reading disabilities: A Controlled factorial evaluation of the influence of IQ, socioeconomic status, and race on outcomes

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    Results from a controlled evaluation of remedial reading interventions are reported: 279 young disabled readers were randomly assigned to a program according to a 2 × 2 × 2 factorial design (IQ, socioeconomic status [SES], and race). The effectiveness of two multiple-component intervention programs for children with reading disabilities (PHAB + RAVE-O; PHAB + WIST) was evaluated against alternate (CSS, MATH) and phonological control programs. Interventions were taught an hour daily for 70 days on a 1:4 ratio at three different sites. Multiple-component programs showed significant improvements relative to control programs on all basic reading skills after 70 hours and at 1-year follow-up. Equivalent gains were observed for different racial, SES, and IQ groups. These factors did not systematically interact with program. Differential outcomes for word identification, fluency, comprehension, and vocabulary were found between the multidimensional pro- grams, although equivalent long-term outcomes and equal continued growth confirmed that different pathways exist to effective reading remediation

    Relations between the Kaufman Brief Intelligence Test (KBIT) and the Wechsler Intelligence Scale for Children - Third edition (WISC-III) in Children with Reading Disability

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    Concurrent validity of The Kaufman Brief Intelligence Test (K-BIT) with the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was evaluated, as well as the K-BIT\u27s accuracy as a predictor of WISC-III scores, in a sample of young children with reading disabilities. The two measures were administered to 65 children from Atlanta, Boston, and Toronto who ranged from 6-5 to 7-11 years of age at testing. Correlations between the verbal, nonverbal, and composite scales of the K-BIT and WISC-III were .60, .48, and .63, respectively. Mean K-BIT scores ranged from 1.2 to 5.0 points higher than the corresponding WISC-III scores. Standard errors of estimation ranged from 10.0 to 12.3 points. In individual cases, K-BIT scores can underestimate or overestimate WISC-III scores by as much as 25 points. Results suggest caution against using the K-BIT exclusively for placement and diagnostic purposes with young children with reading disabilities if IQ scores are required

    BRCA1 and BRCA2 5′ noncoding region variants identified in breast cancer patients alter promoter activity and protein binding

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    © 2018 The Authors. Human Mutation published by Wiley Periodicals, Inc. The widespread use of next generation sequencing for clinical testing is detecting an escalating number of variants in noncoding regions of the genome. The clinical significance of the majority of these variants is currently unknown, which presents a significant clinical challenge. We have screened over 6,000 early-onset and/or familial breast cancer (BC) cases collected by the ENIGMA consortium for sequence variants in the 5′ noncoding regions of BC susceptibility genes BRCA1 and BRCA2, and identified 141 rare variants with global minor allele frequency \u3c 0.01, 76 of which have not been reported previously. Bioinformatic analysis identified a set of 21 variants most likely to impact transcriptional regulation, and luciferase reporter assays detected altered promoter activity for four of these variants. Electrophoretic mobility shift assays demonstrated that three of these altered the binding of proteins to the respective BRCA1 or BRCA2 promoter regions, including NFYA binding to BRCA1:c.-287C\u3eT and PAX5 binding to BRCA2:c.-296C\u3eT. Clinical classification of variants affecting promoter activity, using existing prediction models, found no evidence to suggest that these variants confer a high risk of disease. Further studies are required to determine if such variation may be associated with a moderate or low risk of BC

    Brachyradia, a new genus of the tribe Exechiini (Diptera: Mycetophilidae) from the Oriental and Australasian regions

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    Brachyradia, new genus, is proposed and described for two new species of the tribe Exechiini (Diptera: Mycetophilidae) from the Oriental and Australasian regions. The type species, Brachyradia asianca, new species, is described from Thailand, Malaysia, and Indonesia (Sulawesi), and a second species, Brachyradia australis, new species, from Indonesia (Sulawesi) and Papua New Guinea. The systematic position of the new genus and the zoogeography of the tribe Exechiini are discussed. The new genus shows close-it affinities with Brevicornu with interconnections towards Cordyla, Neallodia, and Anatella. As the latter genera have been considered among the most primitive taxa of the tribe, Brachyradia may generate new and interesting questions about polarities of characters, direction of morphological transformations, and the zoogeographical origin of the Exechiini genera

    Back to the Future: Developing an On-Board System for a Vintage Motorcycle

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    This paper describes complex design of a prototypeof an on-board system for older motorcycle for measuring itsoperational characteristics. The birth of the idea is described,followed by explanation of characteristics measured by thesystem, principles of their measurement, and processing the datafor visualization on a display. The system is designed with theaim of the most minimal intervention into the construction ofthe motorcycle, but being easy to reproduce and durable enoughfor a real deployment and use while riding the motorcycle
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