960 resultados para donor acceptor pair
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The study of canine immunohematology is very important for veterinary transfusion medicine. The objective of this study was to determine the DEA blood type frequencies in a purebred canine blood donor population from Porto Alegre, RS, Brazil. One hundred clinically healthy purebred dogs were chosen, 20 dogs from each breed (Great Dane, Rottweiler, Golden Retriever, German Shepherd and Argentine Dogo). Blood samples were taken in ACD-A tubes and the MSU hemagglutination tube test (MI, USA) was used to determine the blood types. The studied population presented general frequencies of 61% for DEA 1.1, 22% for DEA 1.2, 7% for DEA 3, 100% for DEA 4, 9% for DEA 5 and 16% for DEA 7. A significant association was found between breeds and certain combinations of blood types in this population. The results are in agreement with the literature since most part of the canine population studied was positive for DEA 1.1, the most antigenic blood type in dogs. Differences were found among the studied breeds and those should be considered when selecting a blood donor. The knowledge of blood types frequencies and their combinations in different canine populations, including different breeds, is important because it shows the particularities of each group, helps to keep a data bank of local frequencies and minimizes the risks of transfusion reactions.
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Solceller baserade på organiska halvledare erbjuder en möjlighet till storskalig och billig solenergiproduktion. Organiska halvledare har den fördelen att de är lösningsprocesserbara vilket gör att solceller och andra elektroniska komponenter baserade på dessa halvledare kan tillverkas vid låga temperaturer och med liten energiförbrukning. Nackdelen med dessa material är deras strukturella och energetiska oordning som leder till lägre effektivitet. För att organiska solceller ska kunna kommersialiseras krävs grundläggande insikter i de olika processer som begränsar effektiviteten. En stor del av forskningen om dessa processer har varit fokuserad kring egenskaperna av solcellens olika komponenter (de aktiva materialen) som sådana, medan gränsytorna mellan olika material har fått mindre uppmärksamhet. Gränsytor mellan olika material har distinkt olika egenskaper jämfört med ett rent material, och gränsytors olika egenskaper kan ha en väldigt stor inverkan på hur solcellerna fungerar. Syftet med denna avhandling är att klargöra några olika gränsyterelaterade effekter i organiska dioder och solceller. De gränsytor som behandlas är gränsytan mellan kontakten och det aktiva lagret (metall-organisk) och gränsytan mellan donor och acceptor (organisk-organisk). Resultaten visar att metall-organiska gränsytor måste designas noggrant för att begränsa förlust av effektivitet. En icke-idealisk kontakt leder till starkt reducerad effektivitet på grund av att elektronerna extraheras ineffektivt. Även till synes idealiska kontakter kan orsaka förluster genom spontan laddningsöverföring från metallen till det organiska lagret som effektivt sett minskar på den spänning som cellen kan alstra. Den organisk-organiska gränsytan påverkar hur mycket ström cellen kan alstra och beroende på gränsytans beskaffenhet kan de negativa rekombinationsprocesserna i materialet kontrolleras. ------------------------------------------------- Orgaanisille puolijohteille perustuvat aurinkokennot mahdollistavat suurimuotoisen ja edullisen aurinkoenergiatuotannon. Orgaanisten puolijohteiden etu on että ne voidaan liuottaa, jolloin aurinkokennot ja muut näille johteille perustuvat elektroniset komponentit voidaan valmistaa alhaisessa lämpötilassa kuluttaen vähän energiaa. Materiaalien huonona puolena on kuitenkin niiden rakenteellinen ja energeettinen epäjärjestys, jonka seurauksena niiden tehokkuus on huonompi. Orgaanisten aurinkokennojen kaupallistaminen edellyttää perustavanlaatuista ymmärystä tehokkuutta rajoittavista prosesseista. Aurinkokennotutkimus on pääosin keskittynyt aurinkokennon eri komponenttien (aktiivisten materiaalien) ominaisuuksiin, kun taas eri materiaalien rajapinnat ovat jääneet vähemmälle huomiolle. Eri materiaalien välisillä rajapinnoilla on huomattavan erilaisia ominaisuuksia verrattuna puhtaisiin materiaaleihin. Rajapintojen ominaisuudet voivat kuitenkin vaikuttaa merkittävästi aurinkokennojen toimintaan. Tämän väitöstutkimuksen tarkoituksena on selventää joitain rajapintoihin liittyviä toimintoja orgaanisissa diodeissa ja aurinkokennoissa. Käsiteltävät rajapinnat ovat rajapinta kontaktin ja aktiivisen kerroksen välillä (metallis-orgaaninen) ja rajapinta donorin ja akseptorin välillä (orgaanis-orgaaninen). Tutkimustulokset osoittavat, että metallis-orgaaniset rajapinnat tulee suunnitella huolellisesti, jotta tehokkuuden alenemista voidaan rajoittaa. Mikäli kontakti ei ole ideaalisti suunniteltu, vähenee tehokkuus huomattavasti, mikä johtuu elektronien tehottomasta ekstrahoinnista. Jopa ideaalisilta vaikuttavat kontaktit voivat johtaa tehokkuuden alenemiseen, mikäli varaus siirtyy spontaanisti metallista orgaaniseen kerrokseen, sillä tämä alentaa jännitettä jonka kenno voi tuottaa. Kennon orgaanis-orgaaninen rajapinta vaikuttaa siihen, kuinka paljon virtaa kenno pystyy tuottamaan. Rajapinnan ominaisuuksista riippuen materiaalin rekombinaatio on hallittavissa.
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Allogeneic bone marrow transplantation (alloBMT) is the only curative therapy for chronic myelogenous leukemia (CML). This success is explained by the delivery of high doses of antineoplastic agents followed by the rescue of marrow function and the induction of graft-versus-leukemia reaction mediated by allogeneic lymphocytes against host tumor cells. This reaction can also be induced by donor lymphocyte infusion (DLI) producing remission in most patients with CML who relapse after alloBMT. The immunological mechanisms involved in DLI therapy are poorly understood. We studied five CML patients in the chronic phase, who received DLI after relapsing from an HLA-identical BMT. Using flow cytometry we evaluated cellular activation and apoptosis, NK cytotoxicity, lymphocytes producing cytokines (IL-2, IL-4 and IFN-gamma), and unstimulated (in vivo) lymphocyte proliferation. In three CML patients who achieved hematological and/or cytogenetic remission after DLI we observed an increase of the percent of activation markers on T and NK cells (CD3/DR, CD3/CD25 and CD56/DR), of lymphocytes producing IL-2 and IFN-gamma, of NK activity, and of in vivo lymphocyte proliferation. These changes were not observed consistently in two of the five patients who did not achieve complete remission with DLI. The percent of apoptotic markers (Fas, FasL and Bcl-2) on lymphocytes and CD34-positive cells did not change after DLI throughout the different study periods. Taken together, these preliminary results suggest that the therapeutic effect of DLI in the chronic phase of CML is mediated by classic cytotoxic and proliferative events involving T and NK cells but not by the Fas pathway of apoptosis.
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In this work emission, optical, electrical and magnetic properties of the d- and f- elements doped zinc selenide crystals were investigated within a wide temperature range. Doping was performed in various technological processes: during the growth by chemical vapor transport method; by thermal diffusion from the Bi or Zn melt. Concentration of the doping impurity in the crystals was controlled by amount of the dopant in the source material or by its concentration in the doping media. Special interest in the work was paid to the influence of the different concentrations of Cr and Yb impurities on ZnSe crystals’ properties, correlations between observed effects and similarities with the Ni, Mn and Gd dopants are analysed. Possibility of formation of the excitons bound to the doping d-ions was shown. In contrast to this, it was observed that f-elements do not bound excitons, but prevent formation of excitons bound to some uncontrolled impurities. A mechanism of Cr doping impurity interaction with background impurities and zinc selenide structural defects was proposed based on experimental data. An assumption about resonant energy transfer between double charged chromium ions and complexes based on crystals’ vacancy defects was made. A correlation between emission and magnetic properties of the d- ions doped samples was established. Based on this correlation a mechanism explaining the concentration quench of the emission was proposed. It was found that f-ions bind electrically active shallow and deep donor and acceptor states of background impurity to electrically neutral complexes. This may be observed as “purification” of ZnSe crystals by doping with the rare-earth elements, resulting i tendency of the properties of f-ion doped crystals to the properties of intrinsic crystals, but with smaller concentration of uncontrolled native and impurity defects. A possible interpretation of this effect was proposed. It was shown that selenium substituting impurities decrease efficiency of the Yb doping. Based on this experimental results an attempt to determine ytterbium ion surroundings in the crystal lattice was made. It was shown that co-doping of zinc selenide crystals with the d- and f- ions leads to the combination of the impurities influence on the material’s properties. On the basis of obtained data an interaction mechanism of the d- and f-elements co-dopants was proposed. Guided by the model of the ytterbium ion incorporation in the selenide sublattice of the ZnSe crystals, an assumption about stabilization of single charged chromium ions in the zinc sublattice crystal nodes, by means of formation of the local charge compensating clusters, was made.
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The amino acid arginine (Arg) is a recognized secretagogue of growth hormone (GH), and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO), which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (~250 g) were removed, divided into two halves, pooled (three hemi-pituitaries) and incubated or not with Arg, as well as with different pharmacological agents. Arg (71 mM), the NO donor sodium nitroprusside (SNP, 1 and 0.1 mM) and a cyclic guanosine monophosphate (cGMP) analogue (8-Br-cGMP, 1 mM) increased GH mRNA expression 60 min later. The NO acceptor hemoglobin (0.3 µM) blunted the effect of SNP, and the combined treatment with Arg and L-NAME (a NO synthase (NOS) inhibitor, 55 mM) abolished the stimulatory effect of Arg on GH gene expression. The calcium channel inhibitor nifedipine (3 µM) also abolished Arg-induced GH gene expression. The present study shows that Arg directly induces GH gene expression in hemi-pituitaries isolated from rats, excluding interference from somatostatinergic neurons, which are supposed to be inhibited by Arg. Moreover, the data demonstrate that the NOS/NO signaling pathway and calcium mediate the Arg effects on GH gene expression.
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Our objective was to investigate the protective effect of Lawesson's reagent, an H2S donor, against alendronate (ALD)-induced gastric damage in rats. Rats were pretreated with saline or Lawesson's reagent (3, 9, or 27 µmol/kg, po) once daily for 4 days. After 30 min, gastric damage was induced by ALD (30 mg/kg) administration by gavage. On the last day of treatment, the animals were killed 4 h after ALD administration. Gastric lesions were measured using a computer planimetry program, and gastric corpus pieces were assayed for malondialdehyde (MDA), glutathione (GSH), proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin (IL)-1β], and myeloperoxidase (MPO). Other groups were pretreated with glibenclamide (5 mg/kg, ip) or with glibenclamide (5 mg/kg, ip)+diazoxide (3 mg/kg,ip). After 1 h, 27 µmol/kg Lawesson's reagent was administered. After 30 min, 30 mg/kg ALD was administered. ALD caused gastric damage (63.35±9.8 mm2); increased levels of TNF-α, IL-1β, and MDA (2311±302.3 pg/mL, 901.9±106.2 pg/mL, 121.1±4.3 nmol/g, respectively); increased MPO activity (26.1±3.8 U/mg); and reduced GSH levels (180.3±21.9 µg/g). ALD also increased cystathionine-γ-lyase immunoreactivity in the gastric mucosa. Pretreatment with Lawesson's reagent (27 µmol/kg) attenuated ALD-mediated gastric damage (15.77±5.3 mm2); reduced TNF-α, IL-1β, and MDA formation (1502±150.2 pg/mL, 632.3±43.4 pg/mL, 78.4±7.6 nmol/g, respectively); lowered MPO activity (11.7±2.8 U/mg); and increased the level of GSH in the gastric tissue (397.9±40.2 µg/g). Glibenclamide alone reversed the gastric protective effect of Lawesson's reagent. However, glibenclamide plus diazoxide did not alter the effects of Lawesson's reagent. Our results suggest that Lawesson's reagent plays a protective role against ALD-induced gastric damage through mechanisms that depend at least in part on activation of ATP-sensitive potassium (KATP) channels.
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Maple syrup urine disease (MSUD) is an autosomal recessive disease associated with high levels of branched-chain amino acids. Children with MSUD can present severe neurological damage, but liver transplantation (LT) allows the patient to resume a normal diet and avoid further neurological damage. The use of living related donors has been controversial because parents are obligatory heterozygotes. We report a case of a 2-year-old child with MSUD who underwent a living donor LT. The donor was the patient's mother, and his liver was then used as a domino graft. The postoperative course was uneventful in all three subjects. DNA analysis performed after the transplantation (sequencing of the coding regions of BCKDHA, BCKDHB, andDBT genes) showed that the MSUD patient was heterozygous for a pathogenic mutation in the BCKDHB gene. This mutation was not found in his mother, who is an obligatory carrier for MSUD according to the family history and, as expected, presented both normal clinical phenotype and levels of branched-chain amino acids. In conclusion, our data suggest that the use of a related donor in LT for MSUD was effective, and the liver of the MSUD patient was successfully used in domino transplantation. Routine donor genotyping may not be feasible, because the test is not widely available, and, most importantly, the disease is associated with both the presence of allelic and locus heterogeneity. Further studies with this population of patients are required to expand the use of related donors in MSUD.
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It is currently accepted that superoxide anion (O2•−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.
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Introduction: Pre-implantation kidney biopsy is a decision-making tool when considering the use of grafts from deceased donors with expanded criteria, implanting one or two kidneys and comparing this to post-transplantation biopsies. The role of histopathological alterations in kidney compartments as a prognostic factor in graft survival and function has had conflicting results. Objective: This study evaluated the prevalence of chronic alterations in pre-implant biopsies of kidney grafts and the association of findings with graft function and survival in one year post-transplant. Methods: 110 biopsies were analyzed between 2006 and 2009 at Santa Casa de Porto Alegre, including live donors, ideal deceased donors and those with expanded criteria. The score was computed according to criteria suggested by Remuzzi. The glomerular filtration rate (GFR) was calculated using the abbreviated MDRD formula. Results: No statistical difference was found in the survival of donors stratified according to Remuzzi criteria. The GFR was significantly associated with the total scores in the groups with mild and moderate alterations, and in the kidney compartments alone, by univariate analysis. The multivariate model found an association with the presence of arteriosclerosis, glomerulosclerosis, acute rejection and delayed graft function. Conclusion: Pre-transplant chronic kidney alterations did not influence the post-transplantation one-year graft survival, but arteriosclerosis and glomerulosclerosis is predictive of a worse GFR. Delayed graft function and acute rejection are independent prognostic factors.
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[Acte royal. 1692-07-06. Marienbourg]
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Le dernier feuillet du volume (fol. 39) est formé par l'« Eseroux de la despence de bouche de l'Escurie du Roy,... durant le mois de janvier 1639. »