Apheresis donors and platelet function: inherent platelet responsiveness influences platelet quality

BACKGROUND: Process-induced platelet (PLT) activation occurs with all production methods, including apheresis. Recent studies have highlighted the range and consistence of interindividual variation in the PLT response, but little is known about the contribution of a donors' inherent PLT responsiveness to the activation state of the apheresis PLTs or the effect of frequent apheresis on donors' PLTs. STUDY DESIGN AND METHODS: The relationship between the donors' PLT response on the apheresis PLTs was studied in 47 individuals selected as having PLTs with inherently low, intermediate, or high responsiveness. Whole-blood flow cytometry was used to measure PLT activation (levels of bound fibrinogen) before donation and in the apheresis PLTs. The effects of regular apheresis on the activation status of donors' PLTs were studied by comparing the in vivo activation status of PLTs from apheresis (n = 349) and whole-blood donors (n = 157), before donation. The effect of apheresis per se on PLT activation was measured in 10 apheresis donors before and after donation. RESULTS: The level of PLT activation in the apheresis packs was generally higher than in the donor, and the most activated PLTs were from high-responder donors. There was no significant difference in PLT activation before donation between the apheresis and whole-blood donors (p = 0.697), and there was no consistent evidence of activation in the donors immediately after apheresis. CONCLUSION: The most activated apheresis PLTs were obtained from donors with more responsive PLTs. Regular apheresis, however, does not lead to PLT activation in the donors.

Functional Diversity of Heat-labile Toxins (LT) Produced by Enterotoxigenic Escherichia coli

Heat-labile toxins (LTs) have ADP-ribosylation activity and induce the secretory diarrhea caused by enterotoxigenic Escherichia coli (ETEC) strains in different mammalian hosts. LTs also act as adjuvants following delivery via mucosal, parenteral, or transcutaneous routes. Previously we have shown that LT produced by human-derived ETEC strains encompass a group of 16 polymorphic variants, including the reference toxin (LT1 or hLT) produced by the H10407 strain and one variant that is found mainly among bacterial strains isolated from pigs (LT4 or pLT). Herein, we show that LT4 ( with six polymorphic sites in the A (K4R, K213E, and N238D) and B (S4T, A46E, and E102K) subunits) displays differential in vitro toxicity and in vivo adjuvant activities compared with LT1. One in vitro generated LT mutant (LTK4R), in which the lysine at position 4 of the A subunit was replaced by arginine, showed most of the LT4 features with an similar to 10-fold reduction of the cytotonic effects, ADP-ribosylation activity, and accumulation of intracellular cAMP in Y1 cells. Molecular dynamic studies of the A subunit showed that the K4R replacement reduces the N-terminal region flexibility and decreases the catalytic site crevice. Noticeably, LT4 showed a stronger Th1-biased adjuvant activity with regard to LT1, particularly concerning activation of cytotoxic CD8(+) T lymphocytes when delivered via the intranasal route. Our results further emphasize the relevance of LT polymorphism among human-derived ETEC strains that may impact both the pathogenicity of the bacterial strain and the use of these toxins as potential vaccine adjuvants.

Optimering av hålltidstabeller vid Normaliseringsugnen

Analyserna av hålltiderna i Normaliseringsugnen visar att i de flesta fall kan hålltiderna förkortas, beroende på om man väljer att godkänna värmebehandlingen vid en temperatur15C° eller 5C° under börvärdet. Om 5C° väljas kan det krävas att vissa ugnstider förlängs. Det finns ingen anledning att hålla övertid på plåtarna i ugnen, vilket kan leda till korntillväxt och ett sprött material. Undersökningen visar att övertiden ökar med plåttjockleken. Temperaturavvikelsediagrammet för värmebehandlingen visar att inom tjockleksintervallet 30mm - 50mm är temperaturdifferensen vid hålltidens slut störst gentemot börvärdet. Man bör dock komma ihåg att pyrometern endast mäter yttemperaturen. Kärntemperaturen är förmodligen något lägre och då krävs en viss övertid för att säkerställa en homogen temperatur genom hela plåten. Vid ett lyckat experiment med att plana en plåt, efter att ha värmt upp den till 650°C, gjordes en simulering i dataprogrammet Steeltemp 2D. Simuleringen visar svalningskurvor för en given analyskod från 600°C för olika plåttjocklekar. Temperaturen på experimentplåten vid inträdet i planmaskinen var 350°C. Resultatet som redovisas i Steeltempdiagrammet visar att det inte finns risk att plåttemperaturen sjunker under 350°C.

Framtagning av produktionslayout och produktutveckling för tillverkning av hängskenor till hyllsystem

Med de premisser att det endast är priset som avgör materialvalet i plåten till väggskenorna såverkar inte höghållfast plåt vara något konkurrenskraftigt alternativ till det befintliga ochmjukare stålet som används i väggskenorna i den befintliga utrustningen.Förslaget på en layout av produktionsutrustning för tillverkning av hyllskenor är en komplett ocheffektiv rullformningslinje som tillverkar väggskenor, hålade U-profiler, som sedan är klara förlackering. Förslaget på produktionslayout innebär utrustningsmässigt ett flöde frånutgångsmaterialet, en haspel för plåtband, en slinga går till inledare, stansning av hålbild,rullformningsdel, riktverktyg och slutligen en sax som kan klippa väggskenorna till önskadlängd. Detta skulle innebära en förbättring i form av en mer resurssnål tillverkning (lean) för SalsAB. Sals skulle då i stället för som med dagens befintliga system som bygger på inköp avtillverkade U-profiler då på ett kontrollerat och mer effektivt sätt själva kunna styra och utförahela produktionen av hyllskenor. Produktionen skulle då ske genom att tillverka väggskenornahelt på egen hand från hasplad plåt. Produktionen kan då utföras mot kundorder, ”just in time”,och därmed undkomma behovet av någon lagerföring av obearbetade profiler vilket annars krävsmed de hittills partivis inköpta U-profiler samt att inte vara längre vara beroende av fungerandeleveranser av dessa.

Influência da punção lombar traumática e da quimioterapia intratecal na sobrevida de pacientes pediátricos com leucemia linfocítica aguda

Introdução e Objetivos: O sistema nervoso central (SNC) é o um sítio freqüente de recaída na criança com leucemia linfocítica aguda (LLA). Existe evidência de que a punção lombar traumática (PLT) pode representar um risco adicional de recaída no SNC quando ocorre inoculação de blastos no liqüido céfalorraquidiano (LCR). Este estudo tem por objetivo determinar se a ocorrência da PLT ao diagnóstico afeta o prognóstico de pacientes com essa patologia. Material e Métodos: Setenta e sete pacientes com diagnóstico de LLA, tratados entre 1992 a 2002, foram incluídos na análise. Quimioterapia intratecal (QIT) foi instilada imediatamente após a PL inicial (precoce), ou na segunda PL (tardia), realizada no período de 24 a 48 horas após a realização da PL inicial. Foi feita análise da influência da PLT e do momento (precoce x tardia) de administração da QIT em relação a recaída no SNC. Resultados: Entre os 19 pacientes que apresentaram PLT ao diagnóstico e receberam QIT tardia, seis tiveram recaída isolada no SNC e dois recaída combinada em SNC e medula óssea (MO). Entre os nove pacientes que tiveram PLT e receberam QIT precoce, somente um apresentou recaída combinada em SNC e MO (P=0,20); não houve, portanto, influência estatisticamente significativa da PLT na sobrevida livre de eventos (SLE) (55% para QIT precoce x 49% para QIT tardia) (P=0,37). Entretanto, em análise estratificada, de acordo com grupos de risco, observamos que para pacientes de baixo ou médio risco o OR foi de 0,8 quando recebiam QIT tardia (P=0,99) e 0,17 quando recebiam QIT precoce (P=0,47). Por outro lado, entre pacientes de alto risco o OR para recaída foi de 21,0 para aqueles que recebiam QIT tardia (P=0,09) e 1,5 para o grupo que recebia Q IT precoce (P=0,99). Conclusão: Os resultados do presente estudo são sugestivos de que a ocorrência da PLT tem uma influência adversa no prognóstico de pacientes com LLA de alto risco de recaída. Como estes resultados são decorrentes de um estudo retrospectivo, recomenda-se que sejam confirmados em estudos prospectivos randomizados.

Prevalence and virulence properties of Vibrio cholerae non-O1, Aeromonas spp. and Plesiomonas shigelloides isolated from Cambe Stream (State of Parana, Brazil)

The incidence of Vibrio cholerae, Aeromonas spp, and Plesiomonas shigelloides was determined in Rater samples from Cambe Stream. The samples were collected from seven different sites. The serogroups, virulence markers and drug resistance profiles were also evaluated. Twelve. Aer. hydrophila, 12 Aer. caviae, eight Aer. sobria, seven Ple. shigelloides and two V. cholerae non-O1 were isolated. They belonged to different serogroups and all produced haemolysis in different assays. Five of the Aeromonas strains and one of V, cholerae non-O1 were positive for enterotoxin activity. Haemagglutination and its inhibition, using erythrocytes of different origins, was variable for Aeromonas spp and V. cholerae, while none of the Plt. shigelloides haemagglutinated in association with any type of erythrocyte. All isolates exhibited multiple drug resistance. These results indicate that the occurrence of V. cholerae non-O1, Aeromonas spp, and Ple. shigelloides, in water used for vegetable irrigation, human recreation and animal consumption, among others, represents a potential risk for humans.

Fatores genéticos e de meio na produção de leite de caprinos leiteiros

Objetivou-se, no presente estudo, avaliar a produção de leite de caprinos leiteiros da região sudeste do Brasil, com intuito de verificar os fatores de meio e estimar os parâmetros genéticos pelo método dos mínimos quadrados (MMQ). Os controles de 1336 lactações foram inicialmente ajustados pela função multifásica (difásica) e calculou-se a produção de leite total (PLT). Os dados foram provenientes de sete propriedades e três raças (Parda Alpina, Saanen e Toggenburg). A média e o erro-padrão da PLT estimados pelo MMQ foram de 635,31 ±39,75 kg. A interação ano x estação do parto influenciou a PLT. em um dos anos estudados, a PLT foi menor para as cabras paridas no final da estação. Nas três estações de parto, observou-se comportamento quadrático da PLT, em função dos anos de parto. Para as três estações, a PLT aumentou de 1986 até meados de 1990, decrescendo em seguida. A idade de máxima PLT foi observada aos 46,65 meses. Das três raças estudadas, observou-se que as raças Parda Alpina e Saanen apresentaram alternância de superioridade na PLT em algumas fazendas, porém maiores que a Toggenburg. Os coeficientes de herdabilidade e repetibilidade da PLT estimados pelo MMQ foram de 0,296 ± 0,079 e 0,277 ± 0,033, respectivamente. Estes resultados revelam baixa confiabilidade em poucas observações dessas características ou na inconsistência das estimativas da função multifásica. Como a PLT é uma característica limitada ao sexo, sugere-se o teste de progênie como método de seleção mais eficiente para os reprodutores e uso de inseminação artificial como processo de disseminação do material genético selecionado.

Study on the orientation degree of Pb1-xLaxTiO3 thin films by the rocking curve technique and its morphological aspects

Thin films of perovskite-type materials such as PbTiO3, BaTiO3, (Pb,La)TiO3, (Pb, La)(ZrTi)O-3, KNbO3, and Pb(Mg,Nb)03 have been attracting great interest for applications like non-volatile memories, ultrasonic sensors and optical devices. Thin film should be epitaxially grown or at least highly textured since the properties of this anisotropic material depend on the crystallographic orientation. For optical devices, in particular, an epitaxial thin film without defects are essential to reduce optical propagation losses. Pb1-xLaxTiO3 (PLT) where x=0, 13 and 27% thin films were prepared by a chemical method (polymeric precursors method), and deposited by the spin coating technique onto substrates of SrTiO3 (STO) and LaAlO3 (LAO). The films were then beat treated at 500 degrees C in a controlled atmosphere of 0,. The orientation degree of the thin films was obtained from rocking curve technique, by means of X-ray difftaction analysis. A microstructural study revealed that the films were crack-free, homogeneous and have low roughness. (c) 2006 Elsevier B.V. All rights reserved.

Electronic structure of Pb1-xLaxTiO3 ferroelectric materials from Ti 2p and O 1s soft x-ray absorption spectroscopy

The electronic structure of Pb1-xLaxTiO3 (PLT) compounds for x ranging from 0 to 30 at. % of La is investigated by means of soft x-ray absorption near edge structure (XANES) at the Ti L-3,L-2 and O K edges. The greatest modification in the structure of the Ti 2p XANES spectra of the PLT compounds is observed in the region of the high energy peak of the L-3 edge (e(g) states), which exhibits a splitting in the undoped sample. As the amount of lanthanum increases, this splitting becomes less pronounced. This modification is interpreted as a decrease in the degree of disorder of titanium atoms, which is correlated to the substitution of Pb by La atoms. The structural changes observed at the low energy peaks of the O K-edge XANES spectra of the PLT compounds may be interpreted in terms of hybridization between O 2p, Ti 3d, and Pb 6p orbitals. A decrease in the degree of hybridization observed as Pb atoms are replaced by La atoms may be related to the differences in the ferroelectric properties observed between x=0.0 and x=0.30 compounds. (c) 2006 American Institute of Physics.

Microstructure and electrical properties of perovskite (Pb, La)TiO3 thin film deposited at low temperature by the polymeric precursor method

High-quality (Pb, La)TiO3 ferroelectric thin films were successfully prepared on a Pt(111)/Ti/SiO2/Si(100) substrate for the first time by spin coating, using the polymeric precursor method. The X-ray diffraction patterns show that the films are polycrystalline in nature. This method allows for low temperature (500 degrees C) synthesis, a high quality microstructure and superior dielectric properties. The effects on the microstructure and electrical properties were studied by changing the La content. The films annealed at 500 degreesC have a single perovskite phase with only a tetragonal or pseudocubic structure. As the La content is increased, the dielectric constant of PLT thin films increases from 570 up to 1138 at room temperature. The C-V and P-E characteristics of perovskite thin films prepared at a low temperature show normal ferroelectric behavior, representing the ferroelectric switching property. The remanent polarization and coercive field of the films deposited decreased due to the transformation from the ferroelectric to the paraelectric phase with an increased La content. (C) 2001 Kluwer Academic Publishers.

Nanometric Pb1-xLaxTiO3 (x=0, 0.13 and 0.27) powders obtained by the polymeric precursor method

PLT (Pb1-xLaxTiO3, in which x = 0, 0.13 and 0.27) powders were successfully synthesized using the polymeric precursor method, based on the Pechini method. The polymeric precursors were calcined at temperatures ranging from 350 to 500 degrees C for 4 h. X-ray diffraction (XRD) showed the evolution of the crystalline phase starting from the amorphous precursor. Thermogravimetric analyses (TG) and differential thermal analyses (DTA) of the powder precursors showed the influence of the pH on the elimination of organic material. PLT powders have a tendency to form agglomerates, what can be verified by comparing the values of the average particle sizes obtained by Brunauer-Emmett-Teller method, BET (D-BET) with the values of the average crystallite sizes obtained by XRD (D-XRD). (C) 2007 Elsevier Ltd. All fights reserved.

Standardization of platelet parameters determination in blood samples collected with EDTA

The Abbott Cell-Dyn 3000 automated hematological analyzer prepares a histogram of platelet volume, which is measured by a technique using electrical impedance, inferring from its platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW). This equipment also calculates the plateletcrit (PCT). These platelet parameters may be important to evaluate platelet function, but they require standardization, because platelets swell when in contact with ethylenediaminetetra-acetic acid salts, hence an increase in blood sample storage time produces artificially increased results. To assess the effect of storage time on MPV, PLT, PDW and PCT, blood samples from 23 sickle cell anemia patients during steady state (Group I) and 50 from healthy controls (Group II) were placed in Vacutainer® tubes with dipotassium ethylenediaminetetra-acetic acid and measured over a period of 1440 minutes (24 h) at the following times: immediately after the venipuncture (time 0), 15, 30, 60, 120, 240, 360, 480 and 1440 minutes. The mean values of MPV and PCT were significantly increased (p<0.00001) along the storage time in both groups. The mean values of PLT and PDW were practically stable (p>0.05) throughout the storage time in both groups.

Série plaquetaŕria: Valores de referência e correlações observadas entre os parâmetros plaquetários em uma população aparentemente saudável

Mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) platelet parameters can be important to improve the initial identification of platelet disorders. The purpose of this study is to establish reference values for the platelet count (PLT), MPV, PDW and PCT in a population of 1346 apparently healthy adults, from both sexes, as well as to evaluate the correlations among these platelet parameters and to build the necessary nomograms for the clinical interpretations of the platelet indices. The platelet parameters were analyzed in blood samples collected into dipotassium ethylenediaminetetra-acetic acid (K 2 EDTA) by an electrical aperture-impedance method. There were non-linear and an inverse correlations between MPV and PLT, and between PDW and PLT, throughout the reference range of platelet count: the change in MPV and PDW was most accentuated at the lower platelet counts. Because of this non-linear inverse correlation, MPV versus PLT and PDW versus PLT nomograms were built. These correlations among the platelet parameters on a normal population provide a better understanding of these indices and may contribute to establish the real clinical significance of these platelet parameters in many diseases.

Exigências nutricionais de cabritas saanen em crescimento dos 30 aos 45 kg

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A homotextualidade em “El color del verano”, de Reinaldo Arenas, ou quando o desejo assume corpo no texto

Pós-graduação em Letras - FCLAS