171 research outputs found

    High salt diet impairs cerebral blood flow regulation via salt‐induced angiotensin II suppression

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    ObjectivesThis study sought to determine whether salt‐induced ANG II suppression contributes to impaired CBF autoregulation.MethodsCerebral autoregulation was evaluated with LDF during graded reductions of blood pressure. Autoregulatory responses in rats fed HS (4% NaCl) diet vs LS (0.4% NaCl) diet were analyzed using linear regression analysis, model‐free analysis, and a mechanistic theoretical model of blood flow through cerebral arterioles.ResultsAutoregulation was intact in LS‐fed animals as MAP was reduced via graded hemorrhage to approximately 50 mm Hg. Short‐term (3 days) and chronic (4 weeks) HS diet impaired CBF autoregulation, as evidenced by progressive reductions of laser Doppler flux with arterial pressure reduction. Chronic low dose ANG II infusion (5 mg/kg/min, i.v.) restored CBF autoregulation between the pre‐hemorrhage MAP and 50 mm Hg in rats fed short‐term HS diet. Mechanistic‐based model analysis showed a reduced myogenic response and reduced baseline VSM tone with short‐term HS diet, which was restored by ANG II infusion.ConclusionsShort‐term and chronic HS diet lead to impaired autoregulation in the cerebral circulation, with salt‐induced ANG II suppression as a major factor in the initiation of impaired CBF regulation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149286/1/micc12518_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149286/2/micc12518.pd

    The triune of intestinal microbiome, genetics and inflammatory status and its impact on lower gastrointestinal anastomosis healing

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    Gastrointestinal resections are a common operation and most involve an anastomosis to re-join the ends of the remaining bowel to restore gastrointestinal (GIT) continuity. While most joins heal uneventfully, in up to 26% of patients healing fails and an anastomotic leak (AL) develops. Despite advances in surgical technology and techniques, the rate of anastomotic leaks has not decreased over the last few decades raising the possibility that perhaps we do not yet fully understand this phenomenon of AL and are thus ill-equipped to prevent it. As in all complex conditions it is necessary to isolate each different aspect of disease for interrogation of its specific role, but, as we hope to demonstrate in this article, it is a dangerous oversimplification to consider any single aspect as the full answer to the problem. Instead, consideration of important individual observations in parallel could illuminate the way forward toward a possibly simple solution amidst the complexity. This article details three aspects that we believe intertwine, and therefore should be considered together in wound healing within the GIT, during post-surgical recovery: the microbiome, the host genetic makeup, and their relationship to the peri-operative inflammatory status. Each of these, alone or in combination, has been linked with various states of health and disease, and in combining these three aspects in the case of post-operative recovery from bowel resection, we may be nearer an answer to preventing anastomotic leaks than might have been thought just a few years ago

    Structures in <sup>20</sup>O from the <sup>14</sup>C(<sup>7</sup>Li,<em> p</em>) reaction at 44 MeV

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    We have studied the multi-nucleon transfer reaction 14 C(7 Li, p) at E Lab(7 Li) = 44 MeV populating states of the neutron-rich oxygen isotope 20O . The experiments have been performed at the Munich Tandem accelerator using the high-resolution Q3D magnetic spectrometer, with an overall energy resolution of 45keV. States were populated up to 20MeV excitation energy --65 states have been identified in the analysis, among which 42 are new. Rotational bands are proposed in terms of underlying intrinsic reflection-asymmetric cluster and prolate molecular structures (namely \ensuremath ^{14}{\rm C}\otimes2n\otimes\alpha as parity doublet bands. A rectangular oblate structure is suggested for some very narrow states at high excitation energies

    From the stable to the exotic: clustering in light nuclei

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    A great deal of research work has been undertaken in alpha-clustering study since the pioneering discovery of 12C+12C molecular resonances half a century ago. Our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics, facing some of the greatest challenges and opportunities in the years ahead. The occurrence of "exotic" shapes in light N=Z alpha-like nuclei is investigated. Various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented. Evolution of clustering from stability to the drip-lines is examined: clustering aspects are, in particular, discussed for light exotic nuclei with large neutron excess such as neutron-rich Oxygen isotopes with their complete spectroscopy.Comment: 15 pages, 5 figures, Presented at the International Symposium on "New Horizons in Fundamental Physics - From Neutrons Nuclei via Superheavy Elements and Supercritical Fields to Neutron Stars and Cosmic Rays" held at Makutsi Safari Farm, South Africa, December 23-29, 2015. arXiv admin note: substantial text overlap with arXiv:1402.6590, arXiv:1303.0960, arXiv:1408.0684, arXiv:1011.342

    Molecular and cluster structures in <sup>18</sup>O

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    We have studied the multi-nucleon transfer reaction 12C ( 7Li ,p) at E lab = 44 MeV, populating states in the oxygen isotope 18O . The experiments were performed at the Tandem accelerator of the Maier-Leibniz Laboratory in Munich using the high-resolution Q3D magnetic spectrograph. States were populated up to an excitation energy of 21.2MeV with an overall energy resolution of 45keV, and 30 new states of 18O have been identified. The structure of the rotational bands observed is discussed in terms of cluster bands with the underlying cluster structures: 14C \displaystyle \otimes \displaystyle \alphaand 12C ⊗ 2n ⊗ α \alpha . Because of the broken intrinsic reflection symmetry in these structures the corresponding rotational bands appear as parity doublets

    Measurement of alpha and neutron decay widths of excited states of C-14

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    The 12C 16O,14O 14C reaction was studied at a beam energy of 234 MeV. The 14O ejectile was detected by a Q3D spectrometer at forward angles. The energies and angles of the excited 14C recoil break up fragments were measured in coincidence with the 14O ejectile using a double sided silicon strip detector array at backward angles. A complete kinematic reconstruction of the reaction was performed to reconstruct the 14C rightarrow 10Be and 14C rightarrow 13 n decay channels and the branching ratios and widths of these decays were calculated. Theoretical decay branches were calculated using barrier penetrability factors and were compared to the measured ratios to provide information on the spins, parities, and configurations of the states. Neutron emission was found to be favored for the 11.73, 12.96, 14.87,16.72, and 18.6 MeV states. The 14.87, 18.6, and 21.4 MeV states were found to have a considerable width for decay and are candidates for the three bodied molecular cluster structure of 14

    Protease Activity Increases in Plasma, Peritoneal Fluid, and Vital Organs after Hemorrhagic Shock in Rats

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    Hemorrhagic shock (HS) is associated with high mortality. A severe decrease in blood pressure causes the intestine, a major site of digestive enzymes, to become permeable – possibly releasing those enzymes into the circulation and peritoneal space, where they may in turn activate other enzymes, e.g. matrix metalloproteinases (MMPs). If uncontrolled, these enzymes may result in pathophysiologic cleavage of receptors or plasma proteins. Our first objective was to determine, in compartments outside of the intestine (plasma, peritoneal fluid, brain, heart, liver, and lung) protease activities and select protease concentrations after hemorrhagic shock (2 hours ischemia, 2 hours reperfusion). Our second objective was to determine whether inhibition of proteases in the intestinal lumen with a serine protease inhibitor (ANGD), a process that improves survival after shock in rats, reduces the protease activities distant from the intestine. To determine the protease activity, plasma and peritoneal fluid were incubated with small peptide substrates for trypsin-, chymotrypsin-, and elastase-like activities or with casein, a substrate cleaved by multiple proteases. Gelatinase activities were determined by gelatin gel zymography and a specific MMP-9 substrate. Immunoblotting was used to confirm elevated pancreatic trypsin in plasma, peritoneal fluid, and lung and MMP-9 concentrations in all samples after hemorrhagic shock. Caseinolytic, trypsin-, chymotrypsin-, elastase-like, and MMP-9 activities were all significantly (p<0.05) upregulated after hemorrhagic shock regardless of enteral pretreatment with ANGD. Pancreatic trypsin was detected by immunoblot in the plasma, peritoneal space, and lungs after hemorrhagic shock. MMP-9 concentrations and activities were significantly upregulated after hemorrhagic shock in plasma, peritoneal fluid, heart, liver, and lung. These results indicate that protease activities, including that of trypsin, increase in sites distant from the intestine after hemorrhagic shock. Proteases, including pancreatic proteases, may be shock mediators and potential targets for therapy in shock
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