1,306 research outputs found
Role of the Shiga toxin in the Hemolytic Uremic Syndrome
En los Ășltimos años, las infecciones por Escherichia coli productor de toxina Shiga (STEC) y el desarrollo del SĂndrome UrĂ©mico HemolĂtico (SUH) han cobrado tal relevancia desde el punto de vista clĂnico y como problema de salud pĂșblica, que se considera uno de los patĂłgenos emergentes mĂĄs importantes de infecciones transmitidas por alimentos. Las infecciones por STEC pueden manifestarse dentro de un amplio espectro clĂnico, tales como infecciones asintomĂĄticas intestinales, diarrea acuosa, diarrea sanguinolenta (colitis hemorrĂĄgica) y complicaciones sistĂ©micas conocidas con el nombre de SUH. En Argentina, el SUH es la principal causa pediĂĄtrica de insuficiencia renal aguda y la segunda de insuficiencia renal crĂłnica. Hasta el presente no existe un tratamiento especĂfico para tratar las infecciones por STEC y disminuir la progresiĂłn del SUH. Los mecanismos por los cuales la toxina Shiga (Stx) induce SUH pueden ayudar a encontrar nuevas estrategias para impedir o mejorar el pronĂłstico del SUH. En este artĂculo se describen recientes progresos que contribuyen a entender el papel de Stx en la patogĂ©nesis del SUH y nuevas estrategias usadas para prevenir el pasaje de la toxina a la circulaciĂłn sistĂ©mica durante la fase diarreica o luego del establecimiento del SUH.In the last years, infection associated with Shiga toxin-producing Escherichia coli (STEC) and subsequent Hemolitic-Uremic Syndrome (HUS) became relevant as a public health since it was considered as one of the most important emergent patogen present in the food contaminated by cattle feces. STEC infection may be asymptomatic or begins with a watery diarrhea that may or may not progress to bloody diarrhea (hemorrhagic colitis) and HUS. In Argentina, HUS is the most common pediatric cause of acute renal insufficiency and the second cause of chronic renal failure. Up to now, STEC infection lacks of known effective treatment strategies that diminish risk of progression to HUS. The mechanisms by which Shiga toxin (Stx) induce HUS may help to find strategies to prevent or ameliorate HUS. In this article, recent progress that has contributed to understanding the disease pathogenesis of STEC is reviewed. New strategies to prevent further uptake of Shiga from the gut, either during the diarrheal phase or once HUS has developed are discussed.Fil: Pistone Creydt, Virginia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de BiologĂa y Medicina Experimental. FundaciĂłn de Instituto de BiologĂa y Medicina Experimental. Instituto de BiologĂa y Medicina Experimental; ArgentinaFil: Nuñez, Pablo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Boccoli, Javier. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Silberstein, Claudia Marcela. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Zotta, Elsa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de BiologĂa y Medicina Experimental. FundaciĂłn de Instituto de BiologĂa y Medicina Experimental. Instituto de BiologĂa y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Goldstein, Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Ibarra, Cristina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias FisiolĂłgicas. Laboratorio de Fisiopatogenia; Argentin
Tethering of Gly-Arg-Gly-Asp-Ser-Pro-Lys Peptides on Mg-Doped Hydroxyapatite
Stem cell homing, namely the recruitment of mesenchymal stem cells (MSCs) to injured tissues, is highly effective for bone regeneration in vivo. In order to explore whether the incorporation of mimetic peptide sequences on magnesium-doped (Mg-doped) hydroxyapatite (HA) may regulate the homing of MSCs, and thus induce cell migration to a specific site, we covalently functionalized MgHA disks with two chemotactic/haptotactic factors: either the fibronectin fragment III1-C human (FF III1-C), or the peptide sequence Gly-Arg-Gly-Asp-Ser-Pro-Lys, a fibronectin analog that is able to bind to integrin transmembrane receptors. Preliminary biological evaluation of MSC viability, analyzed by 3-(4,5-dimethylÂthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, suggested that stem cells migrate to the MgHA disks in response to the grafted haptotaxis stimuli
Effect of Ethyl Ester L-Lysine Triisocyanate addition to produce reactive PLA/PCL bio-polyester blends for biomedical applications
We report in this paper the effects of Ethyl Ester L-Lysine Triisocyanate (LTI) on the physical-mechanical properties of Poly(lactide)/Poly(Δ-caprolactone) (PLA/PCL) polyesters blends. The PLA/PCL ratios considered were 20/80, 50/50 and 80/20 (wt/wt %) and LTI was added in amounts of 0.0-0.5-1.0 phr. PLA and PCL reacted with LTI during processing in a Brabender twin screw internal mixer to produce block copolymers in-situ. The resulting blends have been characterized by torque measurements, uniaxial tensile tests, Differential Scanning Calorimeter, contact angle measurements with a Phosphate Buffered Saline (PBS) solution, ATR analysis and morphological SEM observations. Experimental results highlighted how LTI enhanced interaction and dispersion of the two components, resulting into a synergic effect in mechanical properties. Mechanical and physical properties can be tailored by changing the blend composition. The most noticeable trend was an increase in ductility of the mixed polymers. Besides, LTI decreased blendâs wet ability in PBS and lowered the starting of crystalline phase formation for both polymers, confirming an interaction among them. These reactive blends could find use as biomedical materials, e.g. absorbable suture threads or scaffolds for cellular growth
Observation of resonances consistent with pentaquark states in decays
Observations of exotic structures in the channel, that we refer to
as pentaquark-charmonium states, in decays are
presented. The data sample corresponds to an integrated luminosity of 3/fb
acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude
analysis is performed on the three-body final-state that reproduces the
two-body mass and angular distributions. To obtain a satisfactory fit of the
structures seen in the mass spectrum, it is necessary to include two
Breit-Wigner amplitudes that each describe a resonant state. The significance
of each of these resonances is more than 9 standard deviations. One has a mass
of MeV and a width of MeV, while the second
is narrower, with a mass of MeV and a width of MeV. The preferred assignments are of opposite parity, with one
state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after
referee's comments, now 19 figure
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Precise measurements of the properties of the B-1(5721)(0,+) and B-2*(5747)(0,+) states and observation of B-+,B-0 pi(-,+) mass structures
Invariant mass distributions of B+Ïâ and B0Ï+ combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fbâ1 of pp collision data, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Precise measurements of the masses and widths of the B1(5721)0,+ and B2(5747)0,+ states are reported. Clear enhancements, particularly prominent at high pion transverse momentum, are seen over background in the mass range 5850-6000 MeV in both B+Ïâ and B0Ï+ combinations. The structures are consistent with the presence of four excited B mesons, labelled BJ (5840)0,+ and BJ (5960)0,+, whose masses and widths are obtained under different hypotheses for their quantum numbers
Effect of Ethyl Ester L-Lysine Triisocyanate addition to produce reactive PLA/PCL bio-polyester blends for biomedical applications
This paper was accepted for publication in the journal Journal of the Mechanical Behavior of Biomedical Materials and the definitive published version is available at http://dx.doi.org/10.1016/j.jmbbm.2017.02.018We report in this paper the effects of Ethyl Ester L-Lysine Triisocyanate (LTI) on the physical-mechanical properties of Poly(lactide)/Poly(Δ-caprolactone) (PLA/PCL) polyesters blends. The PLA/PCL ratios considered were 20/80, 50/50 and 80/20 (wt/wt %) and LTI was added in amounts of 0.0-0.5-1.0 phr. PLA and PCL reacted with LTI during processing in a Brabender twin screw internal mixer to produce block copolymers in-situ. The resulting blends have been characterized by torque measurements, uniaxial tensile tests, Differential Scanning Calorimeter, contact angle measurements with a Phosphate Buffered Saline (PBS) solution, ATR analysis and morphological SEM observations. Experimental results highlighted how LTI enhanced interaction and dispersion of the two components, resulting into a synergic effect in mechanical properties. Mechanical and physical properties can be tailored by changing the blend composition. The most noticeable trend was an increase in ductility of the mixed polymers. Besides, LTI decreased blendâs wet ability in PBS and lowered the starting of crystalline phase formation for both polymers, confirming an interaction among them. These reactive blends could find use as biomedical materials, e.g. absorbable suture threads or scaffolds for cellular growth
Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study
Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study
Background: The National Research Council (CNR) prostate cancer monitoring project in Italy (Pros-IT CNR) is an observational, prospective, ongoing, multicentre study aiming to monitor a sample of Italian males diagnosed as new cases of prostate cancer. The present study aims to present data on the quality of life at time prostate cancer is diagnosed. Methods: One thousand seven hundred five patients were enrolled. Quality of life is evaluated at the time cancer was diagnosed and at subsequent assessments via the Italian version of the University of California Los Angeles-Prostate Cancer Index (UCLA-PCI) and the Short Form Health Survey (SF-12). Results: At diagnosis, lower scores on the physical component of the SF-12 were associated to older ages, obesity and the presence of 3+ moderate/severe comorbidities. Lower scores on the mental component were associated to younger ages, the presence of 3+ moderate/severe comorbidities and a T-score higher than one. Urinary and bowel functions according to UCLA-PCI were generally good. Almost 5% of the sample reported using at least one safety pad daily to control urinary loss; less than 3% reported moderate/severe problems attributable to bowel functions, and sexual function was a moderate/severe problem for 26.7%. Diabetes, 3+ moderate/severe comorbidities, T2 or T3-T4 categories and a Gleason score of eight or more were significantly associated with lower sexual function scores at diagnosis. Conclusions: Data collected by the Pros-IT CNR study have clarified the baseline status of newly diagnosed prostate cancer patients. A comprehensive assessment of quality of life will allow to objectively evaluate outcomes of different profile of care
Measurement of the forward Z boson production cross-section in pp collisions at âs = 13 TeV
A measurement of the production cross-section of Z bosons in pp collisions at âs=13 TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range 2.0 20 GeV and dilepton invariant mass in the range 60 < m(ââ) < 120 GeV. The integrated cross-section from averaging the two final states is ÏZââ = 194.3 ± 0.9 ± 3.3 ± 7.6 pb, where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable Ïη*
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