259 research outputs found

    Histological and ultrastructural evaluation of the early healing of the lateral collateral ligament epiligament tissue in a rat knee model

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    <p>Abstract</p> <p>Background</p> <p>In this study, we evaluated the changes which occurred in the epiligament, an enveloping tissue of the ligament, during the ligament healing. We assessed the association of epiligament elements that could be involved in ligament healing.</p> <p>Methods</p> <p>Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy.</p> <p>Results</p> <p>At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored.</p> <p>Conclusion</p> <p>Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.</p

    The disruption of proteostasis in neurodegenerative diseases

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    Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Human arachnoid granulations Part I: a technique for quantifying area and distribution on the superior surface of the cerebral cortex

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    <p>Abstract</p> <p>Background</p> <p>The arachnoid granulations (AGs) are herniations of the arachnoid membrane into the dural venous sinuses on the surface of the brain. Previous morphological studies of AGs have been limited in scope and only one has mentioned surface area measurements. The purpose of this study was to investigate the topographic distribution of AGs on the superior surface of the cerebral cortex.</p> <p>Methods</p> <p><it>En face </it>images were taken of the superior surface of 35 formalin-fixed human brains. AGs were manually identified using Adobe Photoshop, with a pixel location containing an AG defined as 'positive'. A set of 25 standard fiducial points was marked on each hemisphere for a total of 50 points on each image. The points were connected on each hemisphere to create a segmented image. A standard template was created for each hemisphere by calculating the average position of the 25 fiducial points from all brains. Each segmented image was mapped to the standard template using a linear transformation. A topographic distribution map was produced by calculating the proportion of AG positive images at each pixel in the standard template. The AG surface area was calculated for each hemisphere and for the total brain superior surface. To adjust for different brain sizes, the proportional involvement of AGs was calculated by dividing the AG area by the total area.</p> <p>Results</p> <p>The total brain average surface area of AGs was 78.53 ± 13.13 mm<sup>2 </sup>(n = 35) and average AG proportional involvement was 57.71 × 10<sup>-4 </sup>± 7.65 × 10<sup>-4</sup>. Regression analysis confirmed the reproducibility of AG identification between independent researchers with r<sup>2 </sup>= 0.97. The surface AGs were localized in the parasagittal planes that coincide with the region of the lateral lacunae.</p> <p>Conclusion</p> <p>The data obtained on the spatial distribution and <it>en face </it>surface area of AGs will be used in an <it>in vitro </it>model of CSF outflow. With an increase in the number of samples, this analysis technique can be used to study the relationship between AG surface area and variables such as age, race and gender.</p

    Association of Fecal Microbial Diversity and Taxonomy with Selected Enzymatic Functions

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    Few microbial functions have been compared to a comprehensive survey of the human fecal microbiome. We evaluated determinants of fecal microbial β-glucuronidase and β-glucosidase activities, focusing especially on associations with microbial alpha and beta diversity and taxonomy. We enrolled 51 healthy volunteers (26 female, mean age 39) who provided questionnaire data and multiple aliquots of a stool, from which proteins were extracted to quantify β-glucuronidase and β-glucosidase activities, and DNA was extracted to amplify and pyrosequence 16S rRNA gene sequences to classify and quantify microbiome diversity and taxonomy. Fecal β-glucuronidase was elevated with weight loss of at least 5 lb. (P = 0.03), whereas β-glucosidase was marginally reduced in the four vegetarians (P = 0.06). Both enzymes were correlated directly with microbiome richness and alpha diversity measures, directly with the abundance of four Firmicutes Clostridia genera, and inversely with the abundance of two other genera (Firmicutes Lactobacillales Streptococcus and Bacteroidetes Rikenellaceae Alistipes) (all P = 0.05–0.0001). Beta diversity reflected the taxonomic associations. These observations suggest that these enzymatic functions are performed by particular taxa and that diversity indices may serve as surrogates of bacterial functions. Independent validation and deeper understanding of these associations are needed, particularly to characterize functions and pathways that may be amenable to manipulation

    Electrophysiological study of local/global processing in Williams syndrome

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    Persons with Williams syndrome (WS) demonstrate pronounced deficits in visuo-spatial processing. The purpose of the current study was to examine the preferred level of perceptual analysis in young adults with WS (n = 21) and the role of attention in the processing of hierarchical stimuli. Navon-like letter stimuli were presented to adults with WS and age-matched typical controls in an oddball paradigm where local and global targets could appear with equal probability. Participants received no explicit instruction to direct their attention toward a particular stimulus level. Behavioral and event-related potential (ERP) data were recorded. Behavioral data indicated presence of a global precedence effect in persons with WS. However, their ERP responses revealed atypical brain mechanisms underlying attention to local information. During the early perceptual analysis, global targets resulted in reduced P1 and enhanced N150 responses in both participant groups. However, only the typical comparison group demonstrated a larger N150 to local targets. At the more advanced stages of cognitive processing, a larger P3b response to global and local targets was observed in the typical group but not in persons with WS, who instead demonstrated an enhanced P3a to global targets only. The results indicate that in a perceptual task, adults with WS may experience greater than typical global-to-local interference and not allocate sufficient attentional resources to local information

    Impact of short-term dietary modification on postprandial oxidative stress

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    <p>Abstract</p> <p>Background</p> <p>We have recently reported that short-term (21-day) dietary modification in accordance with a stringent vegan diet (i.e., a Daniel Fast) lowers blood lipids as well as biomarkers of oxidative stress. However, this work only involved measurements obtained in a fasted state. In the present study, we determined the postprandial response to a high-fat milkshake with regards to blood triglycerides (TAG), biomarkers of oxidative stress, and hemodynamic variables before and following a 21-day Daniel Fast.</p> <p>Methods</p> <p>Twenty-two subjects (10 men and 12 women; aged 35 ± 3 years) completed a 21-day Daniel Fast. To induce oxidative stress, a milkshake (fat = 0.8 g·kg<sup>-1</sup>; carbohydrate = 1.0 g·kg<sup>-1</sup>; protein = 0.25 g·kg<sup>-1</sup>) was consumed by subjects on day one and day 22 in a rested and 12-hour fasted state. Before and at 2 and 4 h after consumption of the milkshake, heart rate (HR) and blood pressure were measured. Blood samples were also collected at these times and analyzed for TAG, malondialdehyde (MDA), hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), advanced oxidation protein products (AOPP), nitrate/nitrite (NOx), and Trolox Equivalent Antioxidant Capacity (TEAC).</p> <p>Results</p> <p>A time effect was noted for HR (<it>p </it>= 0.006), with values higher at 2 hr post intake of the milkshake as compared to pre intake (<it>p </it>< 0.05). Diastolic blood pressure was lower post fast as compared to pre fast (<it>p </it>= 0.02), and a trend for lower systolic blood pressure was noted (<it>p </it>= 0.07). Time effects were noted for TAG (<it>p </it>= 0.001), MDA (<it>p </it>< 0.0001), H<sub>2</sub>O<sub>2 </sub>(<it>p </it>< 0.0001), AOPP (<it>p </it>< 0.0001), and TEAC (<it>p </it>< 0.0001); all concentrations were higher at 2 h and 4 h post intake compared to pre intake, except for TEAC, which was lower at these times (<it>p </it>< 0.05). A condition effect was noted for NOx (<it>p </it>= 0.02), which was higher post fast as compared to pre fast. No pre/post fast × time interactions were noted (<it>p </it>> 0.05), with the area under the curve from pre to post fast reduced only slightly for TAG (11%), MDA (11%), H<sub>2</sub>O<sub>2 </sub>(8%), and AOPP (12%), with a 37% increase noted for NOx.</p> <p>Conclusion</p> <p>Partaking in a 21-day Daniel Fast does not result in a statistically significant reduction in postprandial oxidative stress. It is possible that a longer time course of adherence to the Daniel Fast eating plan may be needed to observe significant findings.</p

    Meat consumption and risk of breast cancer in the UK Women's Cohort Study

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    We performed a survival analysis to assess the effect of meat consumption and meat type on the risk of breast cancer in the UK Women's Cohort Study. Between 1995 and 1998 a cohort of 35 372 women was recruited, aged between 35 and 69 years with a wide range of dietary intakes, assessed by a 217-item food frequency questionnaire. Hazard ratios (HRs) were estimated using Cox regression adjusted for known confounders. High consumption of total meat compared with none was associated with premenopausal breast cancer, HR=1.20 (95% CI: 0.86–1.68), and high non-processed meat intake compared with none, HR=1.20 (95% CI: 0.86–1.68). Larger effect sizes were found in postmenopausal women for all meat types, with significant associations with total, processed and red meat consumption. Processed meat showed the strongest HR=1.64 (95% CI: 1.14–2.37) for high consumption compared with none. Women, both pre- and postmenopausal, who consumed the most meat had the highest risk of breast cancer
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