228 research outputs found

    Platelets activate a pathogenic response to blood-stage Plasmodium infection but not a protective immune response

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    © 2017 by The American Society of Hematology. Clinical studies indicate that thrombocytopenia correlates with the development of severe falciparum malaria, suggesting that platelets either contribute to control of parasite replication, possibly as innate parasite killer cells or function in eliciting pathogenesis. Removal of platelets by anti-CD41 mAb treatment, platelet inhibition by aspirin, and adoptive transfer of wild-type (WT) platelets to CD40-KO mice, which do not control parasite replication, resulted in similar parasitemia compared with control mice. Human platelets at a physiologic ratio of 1 platelet to 9 red blood cells (RBCs) did not inhibit the in vitro development or replication of blood-stage Plasmodium falciparum. The percentage of Plasmodium-infected (iRBCs) with bound platelets during the ascending parasitemia in Plasmodium chabaudi- and Plasmodium berghei-infected mice and the 48-hour in vitro cycle of P falciparum was <10%. P chabaudi and P berghei iRBCs with apoptotic parasites (TdT1) exhibited minimal platelet binding (<5%), which was similar to nonapoptotic iRBCs. These findings collectively indicate platelets do not kill bloodstage Plasmodium at physiologically relevant effector-to-target ratios.Pchabaudi primary andsecondary parasitemiawassimilar in mice depleted of platelets by mAb-injection just before infection, indicating that activation of the protective immune response does not require platelets. In contrast to the lack of an effect on parasite replication, adoptive transfer ofWTplatelets to CD40-KOmice, which are resistant to experimental cerebral malaria, partially restored experimental cerebral malaria mortality and symptoms in CD40-KO recipients, indicating platelets elicit pathogenesis and platelet CD40 is a key molecule

    Hemihepatectomy and Replacement of The Afferent Hepatic Blood Supply in The Dog

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    Hemihepatectomy along with portal vein or hepatic artery replacement in dogs was well tolerated, but combined with replacement of both vessels it was lethal because of outflow block and shock. Total liver blood flow should be kept as high as possible during such procedures in man

    The Multidimensional Study of Viral Campaigns as Branching Processes

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    Viral campaigns on the Internet may follow variety of models, depending on the content, incentives, personal attitudes of sender and recipient to the content and other factors. Due to the fact that the knowledge of the campaign specifics is essential for the campaign managers, researchers are constantly evaluating models and real-world data. The goal of this article is to present the new knowledge obtained from studying two viral campaigns that took place in a virtual world which followed the branching process. The results show that it is possible to reduce the time needed to estimate the model parameters of the campaign and, moreover, some important aspects of time-generations relationship are presented.Comment: In proceedings of the 4th International Conference on Social Informatics, SocInfo 201

    Citrulline protects mice from experimental cerebral malaria by ameliorating hypoargininemia, urea cycle changes and vascular leak

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    © 2019 Gramaglia et al. 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. Clinical and model studies indicate that low nitric oxide (NO) bioavailability due in part to profound hypoargininemia contributes to cerebral malaria (CM) pathogenesis. Protection against CM pathogenesis may be achieved by altering the diet before infection with Plasmodium falcIParum infection (nutraceutical) or by administering adjunctive therapy that decreases CM mortality (adjunctive therapy). This hypothesis was tested by administering citrulline or arginine in experimental CM (eCM). We report that citrulline injected as prophylaxis immediately post infection (PI) protected virtually all mice by ameliorating (i) hypoargininemia, (ii) urea cycle impairment, and (iii) disruption of blood brain barrier. Citrulline prophylaxis inhibited plasma arginase activity. Parasitemia was similar in citrulline- And vehicle control-groups, indicating that protection from pathogenesis was not due to decreased parasitemia. Both citrulline and arginine administered from day 1 PI in the drinking water significantly protected mice from eCM. These observations collectively indicate that increasing dietary citrulline or arginine decreases eCM mortality. Citrulline injected IP on day 4 PI with quinine-injected IP on day 6 PI partially protected mice from eCM; citrulline plus scavenging of superoxide with pegylated superoxide dismutase and pegylated catalase protected all recIPients from eCM. These findings indicate that ameliorating hypoargininemia with citrulline plus superoxide scavenging decreases eCM mortality

    “SPLIT” Pancreaticojejunostomy in the Surgical Treatment of Chronic Pancreatitis

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    “Split” pancreaticojejunostomy is a procedure consisting of vertical transection of the pancreas and anastomosis of both sides of the cut pancreatic duct with an interposed, Roux-en-Y jejunal loop. In this paper we report the long term results of this procedure in the treatment of eight patients with chronic pancreatitis (CP)

    Systematic study of Coulomb distortion effects in exclusive (e,e'p) reactions

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    A technique to deal with Coulomb electron distortions in the analysis of (e,e'p) reactions is presented. Thereby, no approximations are made. The suggested technique relies on a partial-wave expansion of the electron wave functions and a multipole decomposition of the electron and nuclear current in momentum space. In that way, we succeed in keeping the computational times within reasonable limits. This theoretical framework is used to calculate the quasielastic (e,e'p) reduced cross sections for proton knockout from the valence shells in 16^{16}O, 40^{40}Ca, 90^{90}Zr and 208^{208}Pb. The final-state interaction of the ejected proton with the residual nucleus is treated within an optical potential model. The role of electron distortion on the extracted spectroscopic factors is discussed.Comment: 45 pages, 10 encapsulated postscript figures, Revtex, uses epsfig.sty and fancybox.sty, to be published in Physical Review

    Electroinduced two-nucleon knockout and correlations in nuclei

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    We present a model to calculate cross sections for electroinduced two-nucleon emission from finite nuclei. Short-range correlations in the wave functions and meson-exchange contributions to the photoabsorption process are implemented. Effects of the short-range correlations are studied with the aid of a perturbation expansion method with various choices of the Jastrow correlation function. The model is used to investigate the relative importance of the different reaction mechanisms contributing to the A(e,eâ€Č'pn) and A(e,eâ€Č'pp) process. Representative examples for the target nuclei 12^{12}C and 16^{16}O and for kinematical conditions accessible with contemporary high-duty cycle electron accelerators are presented. A procedure is outlined to calculate the two-nucleon knockout contribution to the semi-exclusive (e,eâ€Č'p) cross section. Using this technique we investigate in how far semi-exclusive (e,eâ€Č'p) reactions can be used to detect high-momentum components in the nuclear spectral function.Comment: 51 pages, Latex, uses epsf.sty and elsart.sty, 17 figures (in eps format

    Evidence for shape coexistence in odd-mass rhodium nuclei

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    Results from the study of the ‘@‘Ru (‘He, d) “‘Rh reaction reveal evidence for shape coexistence in odd-mass rhodium isotopes. The strongly excited states at 786, 806, 969, 1019 and 1355 keV in “‘Rh are good candidates for a rotational-like positive-parity band with J”= l/2+, 3/2+, 5/2+, 7/2+ and 9/2+, respectively, coexisting with spherical shell-model states like lg92 2p12 2p32 and lf52 as well as core-coupled configurations

    Polarization degrees of freedom in photoinduced two-nucleon knockout from finite nuclei

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    The polarization degrees of freedom in photoinduced two-nucleon knockout from finite nuclei are studied. It is pointed out that they open good perspectives to study the dynamics of dinucleons in the medium in detail. The (Îł,pp\gamma,pp) and (Îł,pn\gamma,pn) angular cross sections, photon asymmetries and outgoing nucleon polarizations are calculated for the target nuclei 16^{16}O and 12^{12}C and photonenergies ranging from 100 up to 500 MeV. It is investigated to which degree the two-nucleon emission reaction is dominated by photoabsorption on 3S1(T=0)^3S_1(T=0) proton-neutron and 1S0(T=1)^1S_0(T=1) proton-proton pairs in the nuclear medium. The calculations demonstrate that dominance of SS wave photoabsorption in the (Îł,pn\gamma,pn) channel does not necessarily imply that the reaction mechanism is similar to what is observed in deuteron photodisintegration.Comment: 27 pages, REVTeX 3.0 with epsf.sty, 11 figures in EPS forma

    Brain Swelling and Mannitol Therapy in Adult Cerebral Malaria: A Randomized Trial

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    Mild cerebral swelling on CT-scan was common in adult patients with cerebral malaria, but severity of swelling was not correlated with coma depth or survival. Mannitol as adjunctive treatment for cerebral malaria prolonged coma duration and may be harmful
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