162 research outputs found

    Snout Shape in Extant Ruminants

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    Copyright: © 2014 Tennant, MacLeod. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [4.0 license]. The attached file is the published version of the article

    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

    The Pre-Operative Evaluation Clinic: An Underutilized Service in Optimizing Analgesic Outcomes in Patients on Buprenorphine, Methadone, and Naltrexone for Substance Use Disorder or Chronic Pain

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    Addyson E Sand,1 Tyler E Powell,1 Helen T Marry,1 Heather R Rathbun,1 Jenna R Steege,1 Allison LeMahieu,2 Adam K Jacob,1 Ryan S D’Souza,1 Oludare O Olatoye1 1Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA; 2Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USACorrespondence: Oludare O Olatoye, Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA, Email [email protected]: Patients receiving methadone, buprenorphine, and naltrexone for either chronic pain or substance use disorder (SUD) pose perioperative challenges. Due to their complex pharmacology, perioperative recommendations continue to evolve. Deviations from these recommendations may result in worse perioperative outcomes. A formal preoperative evaluation (POE) and optimization of patients on these medications are recommended to address these concerns.Methods: A single-center retrospective electronic health record review was performed with adult patients on methadone, buprenorphine, and naltrexone undergoing elective surgery between January 1, 2010 and December 31, 2020. The primary outcome of interest was the percentage of patients referred to the POE clinic for evaluation prior to the scheduled elective surgery. In addition, we assessed differences in variables (perioperative opioid, hospital length of stay, perioperative multimodal analgesics, perioperative complications, inpatient pain service consult, readmission within 30 days, cancellation of surgery, addiction medicine consult) based on POE clinic evaluation. This analysis was performed separately for patients prescribed these medications for SUD versus chronic pain. Continuous outcomes were analyzed using linear regression with generalized estimating equations (GEE) and robust variance estimates.Results: A total of 714 patients were included in the final analysis, of which 572 (80%) took buprenorphine, methadone, or naltrexone for chronic pain and 142 (20%) took these medications for SUD. Within the chronic pain and SUD subpopulations, 193 (34%) and 35 (25%) patients had formal POE clinic assessments, respectively. Among those taking these medications for chronic pain, POE clinic evaluation was associated with a higher likelihood for receiving non-opioid multimodal analgesics perioperatively (p = 0.016).Conclusion: Formal preoperative evaluations are currently underutilized in patients who take buprenorphine, methadone, or naltrexone for chronic pain or SUD. These patients may benefit from POE clinic assessment to optimize perioperative outcomes.Keywords: preoperative evaluation, chronic opioid therapy, substance use disorder, naltrexone, buprenorphine, methadone, perioperative pain managemen

    MFN2 point mutations occur in 3.4% of Charcot-Marie-Tooth families. An investigation of 232 Norwegian CMT families

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    Background Point mutations in the mitofusin 2 (MFN2) gene has been identified exclusively in Charcot-Marie-Tooth type 2 (CMT2), and in a single family with intermediate CMT. MFN2 point mutations are probably the most common cause of CMT2. Methods Two-hundred and thirty-two consecutive unselected and unrelated CMT families with available DNA from all regions in Norway were included. We screened for point mutations in the MFN2 gene. Results We identified four known and three novel point mutations in 8 unrelated CMT families. The novel point mutations were not found in 100 healthy controls. This corresponds to 3.4% (8/232) of CMT families have point mutations in the MFN2 gene. The phenotypes were compatible with CMT1 in two families, CMT2 in four families, intermediate CMT in one family and distal Hereditary Motor Neuropathy (dHMN) in one family. This corresponds to 2.3% of CMT1, 5.5% of CMT2, 12.5% of intermediate CMT and 6.7% of dHMN families have a point mutation in the MFN2 gene. Point mutations in the MFN2 gene is likely to be the fourth most common cause to CMT after duplication of the peripheral myelin protein 22 (PMP22) gene, and point mutations in the Connexin32 (Cx32) and myelin protein zero (MPZ) genes. Conclusions The identified known and novel point mutations in the MFN2 gene expand the clinical spectrum from CMT2 and intermediate CMT to also include possibly CMT1 and the dHMN phenotypes. Thus, genetic analyses of the MFN2 gene should not be restricted to persons with CMT2

    Exogenous glycosaminoglycans coat damaged bladder surfaces in experimentally damaged mouse bladder

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    BACKGROUND: Interstital cystitis is often treated with exogenous glycosaminoglycans such as heparin, chondroitin sulphate (Uracyst), hyaluronate (Cystistat) or the semi-synthetic pentosan polysulphate (Elmiron). The mechanism of action is presumed to be due to a coating of the bladder surface to replace the normally present chondroitin sulphate and heparan sulphate lost as a result of the disease. This study used fluorescent labelled chondroitin sulphate to track the distribution of glycosaminoglycans administered intravesically to mouse bladder that had been damaged on the surface. METHODS: The surfaces of mouse bladders were damaged by 3 mechanisms – trypsin, 10 mM HCl, and protamine sulphate. Texas Red-labeled chondroitin sulphate was instilled into the bladders of animals with damaged bladders and controls instilled only with saline. Bladders were harvested, frozen, and sectioned for examination by fluorescence. RESULTS: The normal mouse bladder bound a very thin layer of the labelled chondroitin sulphate on the luminal surface. Trypsin- and HCl-damaged bladders bound the labelled chondroitin sulphate extensively on the surface with little penetration into the bladder muscle. Protamine produced less overt damage, and much less labelling was seen, presumably due to loss of the label as it complexed with the protamine intercalated into the bladder surface. CONCLUSION: Glycosaminoglycan administered intravesically does bind to damaged bladder. Given that the changes seen following bladder damage resemble those seen naturally in interstitial cystitis, the mechanisms proposed for the action of these agents is consistent with a coating of damaged bladder

    When Does an Alien Become a Native Species? A Vulnerable Native Mammal Recognizes and Responds to Its Long-Term Alien Predator

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    The impact of alien predators on native prey populations is often attributed to prey naiveté towards a novel threat. Yet evolutionary theory predicts that alien predators cannot remain eternally novel; prey species must either become extinct or learn and adapt to the new threat. As local enemies lose their naiveté and coexistence becomes possible, an introduced species must eventually become ‘native’. But when exactly does an alien become a native species? The dingo (Canis lupus dingo) was introduced to Australia about 4000 years ago, yet its native status remains disputed. To determine whether a vulnerable native mammal (Perameles nasuta) recognizes the close relative of the dingo, the domestic dog (Canis lupus familiaris), we surveyed local residents to determine levels of bandicoot visitation to yards with and without resident dogs. Bandicoots in this area regularly emerge from bushland to forage in residential yards at night, leaving behind tell-tale deep, conical diggings in lawns and garden beds. These diggings were less likely to appear at all, and appeared less frequently and in smaller quantities in yards with dogs than in yards with either resident cats (Felis catus) or no pets. Most dogs were kept indoors at night, meaning that bandicoots were not simply chased out of the yards or killed before they could leave diggings, but rather they recognized the threat posed by dogs and avoided those yards. Native Australian mammals have had thousands of years experience with wild dingoes, which are very closely related to domestic dogs. Our study suggests that these bandicoots may no longer be naïve towards dogs. We argue that the logical criterion for determining native status of a long-term alien species must be once its native enemies are no longer naïve

    Role of potassium and calcium channels in sevoflurane-mediated vasodilation in the foeto-placental circulation

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    <p>Abstract</p> <p>Background</p> <p>Sevoflurane has been demonstrated to vasodilate the foeto-placental vasculature. We aimed to determine the contribution of modulation of potassium and calcium channel function to the vasodilatory effect of sevoflurane in isolated human chorionic plate arterial rings.</p> <p>Methods</p> <p>Quadruplicate <it>ex vivo </it>human chorionic plate arterial rings were used in all studies. <b><it>Series 1 and 2 </it></b>examined the role of the K<sup>+ </sup>channel in sevoflurane-mediated vasodilation. Separate experiments examined whether tetraethylammonium, which blocks large conductance calcium activated K<sup>+ </sup>(K<sub>Ca++</sub>) channels (<b><it>Series 1A+B</it></b>) or glibenclamide, which blocks the ATP sensitive K<sup>+ </sup>(K<sub>ATP</sub>) channel (<b><it>Series 2</it></b>), modulated sevoflurane-mediated vasodilation. <b><it>Series 3 – 5 </it></b>examined the role of the Ca<sup>++ </sup>channel in sevoflurane induced vasodilation. Separate experiments examined whether verapamil, which blocks the sarcolemmal voltage-operated Ca<sup>++ </sup>channel (<b><it>Series 3</it></b>), SK&F 96365 an inhibitor of sarcolemmal voltage-independent Ca<sup>++ </sup>channels (<b><it>Series 4A+B</it></b>), or ryanodine an inhibitor of the sarcoplasmic reticulum Ca<sup>++ </sup>channel (<b><it>Series 5A+B</it></b>), modulated sevoflurane-mediated vasodilation.</p> <p>Results</p> <p>Sevoflurane produced dose dependent vasodilatation of chorionic plate arterial rings in all studies. Prior blockade of the K<sub>Ca++ </sub>and K<sub>ATP </sub>channels augmented the vasodilator effects of sevoflurane. Furthermore, exposure of rings to sevoflurane in advance of TEA occluded the effects of TEA. Taken together, these findings suggest that sevoflurane blocks K<sup>+ </sup>channels. Blockade of the voltage-operated Ca<sup>++</sup>channels inhibited the vasodilator effects of sevoflurane. In contrast, blockade of the voltage-independent and sarcoplasmic reticulum Ca<sup>++</sup>channels did not alter sevoflurane vasodilation.</p> <p>Conclusion</p> <p>Sevoflurane appears to block chorionic arterial K<sub>Ca++ </sub>and K<sub>ATP </sub>channels. Sevoflurane also blocks voltage-operated calcium channels, and exerts a net vasodilatory effect in the <it>in vitro </it>foeto-placental circulation.</p

    Clusters of Conserved Beta Cell Marker Genes for Assessment of Beta Cell Phenotype

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    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Two novel connexin32 mutations cause early onset X-linked Charcot-Marie-Tooth disease

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    <p>Abstract</p> <p>Background</p> <p>X-linked Charcot-Marie Tooth (CMT) is caused by mutations in the connexin32 gene that encodes a polypeptide which is arranged in hexameric array and form gap junctions.</p> <p>Methods</p> <p>We describe two novel mutations in the connexin32 gene in two Norwegian families.</p> <p>Results</p> <p>Family 1 had a c.225delG (R75fsX83) which causes a frameshift and premature stop codon at position 247. This probably results in a shorter non-functional protein structure. Affected individuals had an early age at onset usually in the first decade. The symptoms were more severe in men than women. All had severe muscle weakness in the legs. Several abortions were observed in this family. Family 2 had a c.536 G>A (C179Y) transition which causes a change of the highly conserved cysteine residue, i.e. disruption of at least one of three disulfide bridges. The mean age at onset was in the first decade. Muscle wasting was severe and correlated with muscle weakness in legs. The men and one woman also had symptom from their hands.</p> <p>The neuropathy is demyelinating and the nerve conduction velocities were in the intermediate range (25–49 m/s). Affected individuals had symmetrical clinical findings, while the neurophysiology revealed minor asymmetrical findings in nerve conduction velocity in 6 of 10 affected individuals.</p> <p>Conclusion</p> <p>The two novel mutations in the connexin32 gene are more severe than the majority of previously described mutations possibly due to the severe structural change of the gap junction they encode.</p

    Endothelin-Dependent Vasoconstriction in Human Uterine Artery: Application to Preeclampsia

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    BACKGROUND: Reduced uteroplacental perfusion, the initiating event in preeclampsia, is associated with enhanced endothelin-1 (ET-1) production which feeds the vasoconstriction of uterine artery. Whether the treatments of preeclampsia were effective on ET-1 induced contraction and could reverse placental ischemia is the question addressed in this study. We investigated the effect of antihypertensive drugs used in preeclampsia and of ET receptor antagonists on the contractile response to ET-1 on human uterine arteries. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed, ex vivo, on human uterine artery samples obtained after hysterectomy. We studied variations in isometric tension of arterial rings in response to the vasoconstrictor ET-1 and evaluated the effects of various vasodilators and ET-receptor antagonists on this response. Among antihypertensive drugs, only dihydropyridines were effective in blocking and reversing the ET-1 contractile response. Their efficiency, independent of the concentration of ET-1, was only partial. Hydralazine, alpha-methyldopa and labetalol had no effect on ET-1 induced contraction which is mediated by both ET(A) and ET(B) receptors in uterine artery. ET receptors antagonists, BQ-123 and BQ-788, slightly reduced the amplitude of the response to ET-1. Combination of both antagonists was more efficient, but it was not possible to reverse the maximal ET-1-induced contraction with antagonists used alone or in combination. CONCLUSION: Pharmacological drugs currently used in the context of preeclampsia, do not reverse ET-1 induced contraction. Only dihydropyridines, which partially relax uterine artery previously contracted with ET-1, might offer interesting perspectives to improve placental perfusion
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