1,066 research outputs found

    Polyphosphate in thrombosis, hemostasis, and inflammation

    Full text link
    This illustrated review focuses on polyphosphate as a potent modulator of the plasma clotting cascade, with possible roles in hemostasis, thrombosis, and inflammation. Polyphosphates are highly anionic, linear polymers of inorganic phosphates that are widespread throughout biology. Infectious microorganisms accumulate polyphosphates with widely varying polymer lengths (from a few phosphates to over a thousand phosphates long), while activated human platelets secrete polyphosphate with a very narrow size distribution (about 60‐100 phosphates long). Work from our lab and others has shown that long‐chain polyphosphate is a potent trigger of clotting via the contact pathway, while polyphosphate of the size secreted by platelets accelerates factor V activation, blocks the anticoagulant activity of tissue factor pathway inhibitor, promotes factor XI activation by thrombin, and makes fibrin fibrils thicker and more resistant to fibrinolysis. Polyphosphate also modulates inflammation by triggering bradykinin release, inhibiting the complement system, and modulating endothelial function. Polyphosphate and nucleic acids have similar physical properties and both will trigger the contact pathway—although polyphosphate is orders of magnitude more procoagulant than either DNA or RNA. Important caveats in these studies include observations that nucleic acids and polyphosphate may co‐purify, and that these preparations can be contaminated with highly procoagulant microparticles if silica‐based purification methods are employed. Polyphosphate has received attention as a possible therapeutic, with some recent studies exploring the use of polyphosphate in a variety of formulations to control bleeding. Other studies are investigating treatments that block polyphosphate function as novel antithrombotics with the possibility of reduced bleeding side effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147856/1/rth212162_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147856/2/rth212162.pd

    Observations on Bats from Trinidad, with a Checklist of Species Occurring on the Island

    Get PDF
    In their comprehensive treatment of the bats of Trinidad, Goodwin and Greenhall (1961) reported 58 species from the island. Subsequent authors (Goodwin and Greenhall, 1962, 1964; Genoways et al., 1973a; LaVal, 1973a, 1973b) have added some species to the list and changed the status of others so that the known chiropteran fauna of Trinidad now comprises 64 species: five emballonurids, one noctilionid, four mormoopids, 36 phyllostomids (see Handley, 1980, for family-group names), one natalid, one furipterid, one thyropterid, seven vespertilionids, and eight molossids. Among the phyllostomids, the subfamilies Phyllostominae (15) and Stenodermatinae (14) are the best represented, whereas only a few species of the other three subfamilies Glossophaginae (four), Carolliinae (one), and Desmodontinae (two)-are present. In this paper, we report additional data on 55 species. These data add to the available information concerning distribution, reproduction, and molt. Where appropriate, we have included taxonomic comments on the status of Trinidadian populations. Material reported here is the result of three collecting trips to Trinidad led by R.J. Baker

    Whole body vibration exposure on markers of bone turnover, body composition, and physical functioning in breast cancer patients receiving aromatase inhibitor therapy: A randomized controlled trial

    Get PDF
    Introduction: Women with breast cancer are often prescribed aromatase inhibitors, which can cause rapid loss of bone mass leading to significant potential for morbidity. Vibration training has been shown to be helpful in reducing bone turnover in postmenopausal women without cancer. Aim: To examine the effect of vibration stimulus on markers of bone turnover in breast cancer patients receiving aromatase inhibitors. Methods: Thirty-one breast cancer survivors undergoing treatment with aromatase inhibitors were randomized to vibration stimulus (n = 14) or usual care control (n = 17). Low-frequency and low-magnitude vibration stimulus (27-32 Hz, 0.3g) was delivered in supervised sessions via standing on a vibration platform for 20 minutes, 3 times per week for 12 weeks. The primary outcome was blood markers of bone resorption (serum N-telopeptide X/creatine) and formation (serum type 1 procollagen N-terminal propeptide; P1NP). Other study outcomes body composition as well as measures of physical functioning. Outcomes were compared between groups using analysis of covariance adjusted for baseline values as well as time on aromatase inhibitors. Outcomes: On average, participants were 61.5 years old and overweight (ie, body mass index = 28.5 kg/m2). Following vibration training, there was no significant difference between groups for bone resorption (adjusted group difference 0.5, P = .929) or formation (adjusted group difference 5.3, P = .286). There were also no changes in any measure of physical functioning body composition. Conclusions: Short-term low-magnitude vibration stimulus does not appear to be useful for reducing markers of bone turnover secondary to aromatase inhibitors in breast cancer patients; nor is it useful in improving physical function or symptoms. However, further investigations with larger samples and higher doses of vibration are warranted. Trial Registration: Australian and New Zealand Clinical Trials Registry (ACTRN12611001094965)

    How does a newly encountered face become familiar? The effect of within-person variability on adults' and children's perception of identity

    Get PDF
    Adults and children aged 6 years and older easily recognize multiple images of a familiar face, but often perceive two images of an unfamiliar face as belonging to different identities. Here we examined the process by which a newly encountered face becomes familiar, defined as accurate recognition of multiple images that capture natural within-person variability in appearance. In Experiment 1 we examined whether exposure to within-person variability in appearance helps children learn a new face. Children aged 6-13 years watched a 10-min video of a woman reading a story; she was filmed on a single day (low variability) or over three days, across which her appearance and filming conditions (e.g., camera, lighting) varied (high variability). After familiarization, participants sorted a set of images comprising novel images of the target identity intermixed with distractors. Compared to participants who received no familiarization, children showed evidence of learning only in the high-variability condition, in contrast to adults who showed evidence of learning in both the low- and high-variability conditions. Experiment 2 highlighted the efficiency with which adults learn a new face; their accuracy was comparable across training conditions despite variability in duration (1 vs. 10min) and type (video vs. static images) of training. Collectively, our findings show that exposure to variability leads to the formation of a robust representation of facial identity, consistent with perceptual learning in other domains (e.g., language), and that the development of face learning is protracted throughout childhood. We discuss possible underlying mechanisms

    Mercury's Magnetopause and Bow Shock from MESSENGER Magnetometer Observations

    Get PDF
    We have established the average shape and location of Mercury's magnetopause and bow shock from orbital observations by the MESSENGER Magnetometer. We fit empirical models to midpoints of boundary crossings and probability density maps of the magnetopause and bow shock positions. The magnetopause was fit by a surface for which the position R from the planetary dipole varies as [1 + cos(theta)]-alpha, where theta is the angle between R and the dipole-Sun line, the subsolar standoff distance Rss is 1.45 RM (where RM is Mercury's radius), and the flaring parameter alpha = 0.5. The average magnetopause shape and location were determined under a mean solar wind ram pressure PRam of 14.3 nPa. The best fit bow shock shape established under an average Alfvén Mach number (MA) of 6.6 is described by a hyperboloid having Rss = 1.96 RM and an eccentricity of 1.02. These boundaries move as PRam and MA vary, but their shapes remain unchanged. The magnetopause Rss varies from 1.55 to 1.35 RM for PRam in the range of 8.8-21.6 nPa. The bow shock Rss varies from 2.29 to 1.89 RM for MA in the range of 4.12-11.8. The boundaries are well approximated by figures of revolution. Additional quantifiable effects of the interplanetary magnetic field are masked by the large dynamic variability of these boundaries. The magnetotail surface is nearly cylindrical, with a radius of ~2.7 RM at a distance of 3 RM downstream of Mercury. By comparison, Earth's magnetotail flaring continues until a downstream distance of ~10 Rss

    Multisensory processing and proprioceptive plasticity during resizing illusions

    Get PDF
    Bodily resizing illusions typically use visual and/or tactile inputs to produce a vivid experience of one’s body changing size. Naturalistic auditory input (an input that reflects the natural sounds of a stimulus) has been used to increase illusory experience during the rubber hand illusion, whilst non-naturalistic auditory input can influence estimations of finger length. We aimed to use a non-naturalistic auditory input during a hand-based resizing illusion using augmented reality, to assess whether the addition of an auditory input would increase both subjective illusion strength and measures of performance-based tasks. Forty-four participants completed the following three conditions: no finger stretching, finger stretching without tactile feedback and finger stretching with tactile feedback. Half of the participants had an auditory input throughout all the conditions, whilst the other half did not. After each condition, the participants were given one of the following three performance tasks: stimulated (right) hand dot touch task, non-stimulated (left) hand dot touch task, and a ruler judgement task. Dot tasks involved participants reaching for the location of a virtual dot, whereas the ruler task concerned estimates of the participant’s own finger on a ruler whilst the hand was hidden from view. After all trials, the participants completed a questionnaire capturing subjective illusion strength. The addition of auditory input increased subjective illusion strength for manipulations without tactile feedback but not those with tactile feedback. No facilitatory effects of audio were found for any performance task. We conclude that adding auditory input to illusory finger stretching increased subjective illusory experience in the absence of tactile feedback but did not affect performance-based measures

    Treatment options for muscle-invasive urothelial cancer for patients who were not eligible for cystectomy or neoadjuvant chemotherapy with methotrexate, vinblastine, doxorubicin, and cisplatin

    Full text link
    BACKGROUND. Many patients with invasive urothelial cell cancer are poor candidates for cisplatin-based chemotherapy, and many are high risk for cystectomy. Southwest Oncology Group Trial 8733 was designed to address treatment for such patients. METHODS. Eligible patients had primary or recurrent muscle-invasive disease with transitional cell or squamous cell histology, a performance status from 0 to 2, no extrapelvic disease, a life expectancy >3 months, and adequate hematologic function. The treating clinician assigned patients to operable or inoperable groups. All patients received 2 cycles of 5-fluorouracil (5-FU) at a dose of 1000mg/m 2 per day × 4 starting concurrently with radiation at a dose of 200 centigrays per day × 10 each cycle. After 2 cycles, operable patients with positive biopsies underwent cystectomy, and patients with negative biopsies received a third cycle of chemoradiotherapy. Patients in the inoperable group received 3 cycles without interim biopsy. RESULTS. Eighteen of 24 eligible patients in the operable group were evaluable for response. Five patients had a complete response (CR), 9 patients had stable disease, 1 patient had progressive disease, and 3 patients were not assessable. The median progression-free survival was 10 months (95% confidence interval [95% CI], 4–14 months), and the median overall survival was 18 months (95% CI, 7–28 months). In the inoperable group, 35 of 37 eligible patients were evaluable for response with 17 CRs (49%; 95% CI, 31%–66%). The median progression-free survival was 13 months (95% CI, 10–17 months), and the median overall survival was 20 months (95% CI, 11–53 months). There were no episodes of grade 4 toxicity. CONCLUSIONS. In the current study, the combination of 5-FU and radiation was found to be tolerated well by patients with numerous comorbidities who could not tolerate cisplatin-based therapy or cystectomy. Cancer 2008. © 2008 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58591/1/23420_ftp.pd
    corecore