1,148 research outputs found

    The inflammation, vascular repair and injury responses to exercise in fit males with and without Type 1 diabetes: an observational study.

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    Type 1 diabetes is associated with raised inflammation, impaired endothelial progenitor cell mobilisation and increased markers of vascular injury. Both acute and chronic exercise is known to influence these markers in non-diabetic controls, but limited data exists in Type 1 diabetes. We assessed inflammation, vascular repair and injury at rest and after exercise in physically-fit males with and without Type 1 diabetes.Ten well-controlled type 1 diabetes (27 ± 2 years; BMI 24 ± 0.7 kg.m(2); HbA1c 53.3 ± 2.4 mmol/mol) and nine non-diabetic control males (27 ± 1 years; BMI 23 ± 0.8 kg.m(2)) matched for age, BMI and fitness completed 45-min of running. Venous blood samples were collected 60-min before and 60-min after exercise, and again on the following morning. Blood samples were processed for TNF-α using ELISA, and circulating endothelial progenitor cells (cEPCs; CD45(dim)CD34(+)VEGFR2(+)) and endothelial cells (cECs; CD45(dim)CD133(-)CD34(+)CD144(+)) counts using flow-cytometry.TNF-α concentrations were 4-fold higher at all-time points in Type 1 diabetes, when compared with control (P 0.05). Within the Type 1 diabetes group, the delta change in cEPCS from rest to the following morning was related to HbA1c (r = -0.65, P = 0.021) and TNF-α (r = -0.766, P = 0.005).Resting cEPCs and cECs in Type 1 diabetes patients with excellent HbA1c and high physical-fitness are comparable to healthy controls, despite eliciting 4-fold greater TNF-α. Furthermore, Type 1 diabetes patients appear to have a blunted post-exercise cEPCs response (vascular repair), whilst a biomarker of vascular injury (cECs) remained comparable to healthy controls

    Seagrass can mitigate negative ocean acidification effects on calcifying algae

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    The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm structure and experimental assistance.info:eu-repo/semantics/publishedVersio

    Pattern-Sensitive Epilepsy. I: A Demonstration of a Spatial Frequency Selective Epileptic Response to Gratings

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    Rare individuals suffer epileptic seizures when they view certain images, particularly stripes. Contrast-threshold functions (the ability to see faint stripes of various widths) were determined for two pattern-sensitive brothers, and the epileptogenicity of various patterns was assessed for one of them. Sine wave grating contrast-detection thresholds for the two subjects were essentially normal, with lowest thresholds at approximately 2 cycles/ degree (c/deg). Epileptiform discharges occurred maximally at 5 c/deg with a 1-octave 50% bandwidth. Pattern epileptogenicity was increased by the addition of a third harmonic sine wave grating to its fundamental, but was unaffected by the phase relation of the two gratings. The frequency selectivity of epileptic responsiveness was quantitatively similar to a “spatial frequency channel.” Inhibitory interactions were not present. The findings suggest relations between the phenomena of pattern-sensitive epilepsy and hypothesized spatial frequency channels which merit further exploration. RESUMEN De manera excepcional, hay personas que pueden tener ataques epilÉpticos cuando ven ciertas imÁgenes, particularmente rayas. Se determinaron los umbrales para contrastes (la capacidad de ver rayas de diversas anchuras y muy tenues) en dos hermanos sensibles a patrones y se estableciÓ la epileptogeneidad de di versos patrones en uno de ellos. Los umbrales para contrastes fueron esencialmente normales en los dos sujetos cuando se utilizeÓ una rejilla hecha con ondas sinusoidales, siendo el umbral inferior unos 2 ciclos/ grado (c/deg). Descargas epileptiformes tuvieron lugar de modo mÁximo a 5 c/deg con una amplitud de banda del 50% de una octava. la capacidad epileptogÉnica del partÓn aumentÓ cuando se aÑadiÓ una tercera sinusoide armÓnica a la rejilla base pero esa capacidad no se viÓ alterada por la relaciÓn de fase entre las dos rejillas. La selectividad de la frecuencia de la respuesta epileptogÉnica fue cuantitativamente similar al “canal de frecuencia espacial”. No se observaron interacciones inhibitorias. Los hallazgos sugieren que hay relaciones entre la epilepsyÍa secundaria a patrones visuales y los hipotÉticos canales de frecuencia espacial, lo cual merece mÁs investigaciÓn.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65270/1/j.1528-1157.1980.tb04075.x.pd

    Conventional and CT angiography in children: dosimetry and dose comparisons

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    Tremendous advances have been made in imaging in children with both congenital and acquired heart disease. These include technical advances in cardiac catheterization and conventional angiography, especially with advancements in interventional procedures, as well as noninvasive imaging with MR and CT angiography. With rapid advances in multidetector CT (MDCT) technology, most recently 64-detector array systems (64-slice MDCT), have come a number of advantages over MR. However, both conventional and CT angiography impart radiation dose to children. Although the presence of radiation exposure to children has long been recognized, it is apparent that our ability to assess this dose, particularly in light of the rapid advancements, has been limited. Traditional methods of dosimetry for both conventional and CT angiography are somewhat cumbersome or involve a potential for substantial uncertainty. Recent developments in dosimetry, including metal oxide semiconductor field effect transistors (MOSFET) and the availability of anthropomorphic, tissue-equivalent phantoms have provided new opportunities for dosimetric assessments. Recent work with this technology in state-of-the-art cardiac angiography suites as well as with MDCT have offered direct comparisons of doses in infants and children undergoing diagnostic cardiac evaluation. It is with these dose data that assessment of risks, and ultimately the assessment of risk-benefit, can be better achieved

    Dynamics of trimming the content of face representations for categorization in the brain

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    To understand visual cognition, it is imperative to determine when, how and with what information the human brain categorizes the visual input. Visual categorization consistently involves at least an early and a late stage: the occipito-temporal N170 event related potential related to stimulus encoding and the parietal P300 involved in perceptual decisions. Here we sought to understand how the brain globally transforms its representations of face categories from their early encoding to the later decision stage over the 400 ms time window encompassing the N170 and P300 brain events. We applied classification image techniques to the behavioral and electroencephalographic data of three observers who categorized seven facial expressions of emotion and report two main findings: (1) Over the 400 ms time course, processing of facial features initially spreads bilaterally across the left and right occipito-temporal regions to dynamically converge onto the centro-parietal region; (2) Concurrently, information processing gradually shifts from encoding common face features across all spatial scales (e.g. the eyes) to representing only the finer scales of the diagnostic features that are richer in useful information for behavior (e.g. the wide opened eyes in 'fear'; the detailed mouth in 'happy'). Our findings suggest that the brain refines its diagnostic representations of visual categories over the first 400 ms of processing by trimming a thorough encoding of features over the N170, to leave only the detailed information important for perceptual decisions over the P300

    Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum

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    Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3) of A. suum was constructed by suppressive-subtractive hybridization (SSH), and a subset of cDNAs from 3075 clones subjected to microarray analysis using cDNA probes derived from RNA from different developmental stages of A. suum. The cDNAs (n = 498) shown by microarray analysis to be enriched in the L3 were sequenced and subjected to bioinformatic analyses using a semi-automated pipeline (ESTExplorer). Using gene ontology (GO), 235 of these molecules were assigned to ‘biological process’ (n = 68), ‘cellular component’ (n = 50), or ‘molecular function’ (n = 117). Of the 91 clusters assembled, 56 molecules (61.5%) had homologues/orthologues in the free-living nematodes Caenorhabditis elegans and C. briggsae and/or other organisms, whereas 35 (38.5%) had no significant similarity to any sequences available in current gene databases. Transcripts encoding protein kinases, protein phosphatases (and their precursors), and enolases were abundantly represented in the L3 of A. suum, as were molecules involved in cellular processes, such as ubiquitination and proteasome function, gene transcription, protein–protein interactions, and function. In silico analyses inferred the C. elegans orthologues/homologues (n = 50) to be involved in apoptosis and insulin signaling (2%), ATP synthesis (2%), carbon metabolism (6%), fatty acid biosynthesis (2%), gap junction (2%), glucose metabolism (6%), or porphyrin metabolism (2%), although 34 (68%) of them could not be mapped to a specific metabolic pathway. Small numbers of these 50 molecules were predicted to be secreted (10%), anchored (2%), and/or transmembrane (12%) proteins. Functionally, 17 (34%) of them were predicted to be associated with (non-wild-type) RNAi phenotypes in C. elegans, the majority being embryonic lethality (Emb) (13 types; 58.8%), larval arrest (Lva) (23.5%) and larval lethality (Lvl) (47%). A genetic interaction network was predicted for these 17 C. elegans orthologues, revealing highly significant interactions for nine molecules associated with embryonic and larval development (66.9%), information storage and processing (5.1%), cellular processing and signaling (15.2%), metabolism (6.1%), and unknown function (6.7%). The potential roles of these molecules in development are discussed in relation to the known roles of their homologues/orthologues in C. elegans and some other nematodes. The results of the present study provide a basis for future functional genomic studies to elucidate molecular aspects governing larval developmental processes in A. suum and/or the transition to parasitism

    The Lingering Effects of an Artificial Blind Spot

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    BACKGROUND: When steady fixation is maintained on the centre of a large patch of texture, holes in the periphery of the texture rapidly fade from awareness, producing artificial scotomata (i.e., invisible areas of reduced vision, like the natural ‘blind spot’). There has been considerable controversy about whether this apparent ‘filling in’ depends on a low-level or high-level visual process. Evidence for an active process is that when the texture around the scotomata is suddenly removed, phantasms of the texture appear within the previous scotomata. METHODOLOGY: To see if these phantasms were equivalent to real low-level signals, we measured contrast discrimination for real dynamic texture patches presented on top of the phantasms. PRINCIPAL FINDINGS: Phantasm intensity varied with adapting contrast. Contrast discrimination depended on both (real) pedestal contrast and phantasm intensity, in a manner indicative of a common sensory threshold. The phantasms showed inter-ocular transfer, proving that their effects are cortical rather than retinal. CONCLUSIONS: We show that this effect is consistent with a tonic spreading of the adapting texture into the scotomata, coupled with some overall loss of sensitivity. Our results support the view that ‘filling in’ happens at an early stage of visual processing, quite possibly in primary visual cortex (V1)
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