Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to evaluate the influence of lipid peroxidation on decrease of erythrocyte viability in total blood of cats stored in plastic bags containing CPDA-1 (citrate phosphate dextrose adenine) and CPD / SAG-M (citrate, phosphate, dextrose, saline, adenine, glucose, mannitol) for 28 days. It was also analyzed the biochemical and hematological parameters of feline blood throughout the storage period. To this end, were used 12 cats, adult, healthy, male and female, mixed breed, weighing on average 3.5 ± 0.6 kg. The animals were randomly divided into two experimental groups, designated G1 and G2, which was collected on average 15 mL/kg of blood, and stored in bags for shipment of blood products. For the preservation of blood it was used to G1 and G2 CPDA-1 and CPD / SAG-M, respectively. The blood was kept under refrigeration (1-6 ° C) for 28 days and samples were taken for analysis weekly. These rates were evaluated for lipid peroxidation measured by TBARS (thiobarbituric acid reactive substances), erythrocytes peroxidation in vitro, concentrations of potassium (K +) , lactate, glucose and extracellular hemoglobin, erythrocyte count, hematocrit (Ht), hemoglobin (Hb) and total plasma protein (TPP) Through these evaluations it was found that the lactate, potassium and extracellular hemoglobin are effective parameters to evaluate the quality of stored blood to felines and the analysis of TBARS applies to prove the association of lipid peroxidation decreased the viability of blood, also for the felines. Moreover, CPD/SAG-M was more efficient than CPDA-1 in maintaining the viability of the feline blood after 14 days in a storage period of 28 days. / Esse estudo teve por objetivo avaliar a influência da peroxidação lipídica sobre a diminuição da viabilidade eritrocitária no sangue total de gatos, armazenado em bolsas plásticas contendo CPDA-1 (citrato, fosfato, dextrose, adenina) e CPD/SAG-M (citrato, fosfato, dextrose, salina, adenina glicose, manitol) durante de 28 dias. Também se buscou analisar os parâmetros bioquímicos e hematológicos do sangue felino durante todo o período de armazenamento. Para tal, foram utilizados 12 gatos, adultos, hígidos, de ambos os sexos, sem raça definida (s.r.d.), pesando em média 3,5±0,6 kg. Os animais foram distribuídos aleatoriamente em dois grupos experimentais, denominados G1 e G2, dos quais se coletou em média 15 mL/kg de sangue, e armazenou-se em bolsas para transferência de hemoderivados. Para a conservação do sangue do G1 foi utilizado CPDA-1 e, para o G2, utilizou-se CPD/SAG-M. O sangue foi mantido sob refrigeração (1 a 6ºC) durante 28 dias e foram retiradas amostras para análise semanalmente. Essas alíquotas foram avaliadas quanto à peroxidação lipídica, medida através de TBARS (substâncias que reagem ao ácido tiobarbitúrico), peroxidação de eritrócitos in vitro concentrações de potássio (K+), lactato, glicose e hemoglobina extracelular, contagem total de eritrócitos, hematócrito (Ht), hemoglobina (Hb), e proteínas plasmáticas totais (PPT) Por meio dessas avaliações constatou-se que os níveis de lactato, potássio e hemoglobina extracelular são eficientes parâmetros para avaliação da qualidade do sangue estocado para e espécie felina e que a análise de TBARS é válida para comprovar a associação da peroxidação lipídica à diminuição da viabilidade sanguínea, também para a espécie felina. Além disso, CPD/SAG-M mostrou-se mais eficiente que CPDA-1 na manutenção da viabilidade do sangue felino a partir do 14o dia, em um período de estocagem de 28 dias.

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The conformational conversion of the cellular prion protein (PrPc) to the misfolded isoform (PrPsc) is the central pathogenic event in the transmissible neurodegenerative prion diseases. The recently shown transmissibility of variant Creutzfeldt-Jakob disease by blood transfusion emphasizes the need for better understanding of the PrPc in blood. In the current thesis, we focused on blood platelet PrPc, which has not been very well described so far. In the first part of the thesis, platelet PrPc was characterized as glycosylphosphatidylinositol- anchored glycoprotein with dominant diglycosylated form. Platelet PrPc was shown to be sensitive to cleavage with proteinase K, which is a feature discriminating between cellular and pathological prion protein. We have confirmed that platelet PrPc binds copper ions by its N- terminal octapeptide repeat region. Regarding quantity of PrPc molecules expressed on blood elements we have proved that both platelets and red blood cells express considerable amount of PrPc and thus can not be neglected in the problematic of prions transmission by blood transfusion. The detailed study regarding PrPc localization in blood platelets is presented in the second part of the thesis. PrPc was shown to be expressed in -granules as well as on the cytoplasmic membrane of...

Plus de la moitié des enfants survivant à une maladie critique sont anémiques à leur sortie des soins intensifs pédiatriques (SIP). Cette proportion est inquiétante puisqu’il existe une association entre l’anémie et un développement neurocognitif anormal chez le jeune enfant. Les causes d’anémie aux soins intensifs sont multiples. Le volume de sang prélevé à visée diagnostique est un facteur de risque probable mais aussi un facteur de risque qui est potentiellement modifiable. Ce mémoire explore la contribution des prélèvements sanguins à la prévalence d’anémie chez les enfants atteints d’une maladie critique. L’objectif global est d’une part d’évaluer les pratiques cliniques actuelles de prélèvements sanguins et d’autre part d’évaluer les stratégies étudiées dans la littérature pouvant nous permettre de réduire de manière sécuritaire les quantités de sang retirées à ces enfants. On présente deux articles : une étude de cohorte prospective observationnelle des pratiques de prélèvements sanguins dans notre service de soins intensifs pédiatriques ainsi qu’un scoping review de la littérature des interventions visant à réduire les pertes sanguines à visée diagnostique. La 1ère étude souligne le problème d’anémie iatrogène aux soins intensifs pédiatriques. Cette étude démontre que le volume de sang prélevé pour des raisons diagnostiques est significatif et égal à environ 5% du volume de sang circulant total. Nous démontrons également qu’il y a une association entre les prélèvements sanguins et un risque élevé d’anémie à la sortie des soins intensifs. La 2ème étude résume la littérature actuelle des stratégies efficaces destinées à réduire le sang prélevé en volume et fréquence, réduire l’anémie et également les besoins en transfusion. Les systèmes de prélèvement à circuit clos, les tubes de petit volume, et les tests sanguins réalisés au chevet pour répondre à une question clinique, sont tous des interventions prometteuses. La modification des habitudes de prescription de l’équipe médicale semble également essentielle. Ce mémoire nous permettra de mieux comprendre le problème de l’anémie iatrogène chez les enfants admis aux soins intensifs. Il est important de continuer à améliorer notre pratique actuelle et de minimiser le volume de sang prélevé et/ou gaspillé. / More than 50% of pediatric intensive care unit (PICU) survivors are anemic at PICU discharge. This proportion is worrisome because of the known negative association between anemia and neurocognitive development of young children. The etiology of critical care anemia is multifactorial. Diagnostic blood sampling is an iatrogenic contributor to this problem, but it is also a potentially modifiable factor. The overall objective of our project is to explore current clinical practice for diagnostic blood sampling in PICU and to look for solutions to improve patient care. In this thesis, we present two articles: a prospective observational cohort study, conducted in our PICU, and a scoping review of the existing literature on interventions to minimize diagnostic blood loss. The 1st study highlights the existing problem of iatrogenic anemia in PICU. Our study demonstrates that the volume of blood sampled for diagnostic purposes is significant. Nearly 5% of total circulating blood volume is removed from a critical ill child during a PICU stay. This study detected an association between blood sampling volume and a higher risk of anemia at PICU discharge. The 2nd study summarizes current evidence on efficacious strategies to minimize blood sampling volume and frequency, anemia, and transfusion. Closed blood sampling devices, small volume blood collection tubes, point-of-care testing, and medical education, are all promising interventions. This thesis, which includes both articles, helps us to better understand the problem of iatrogenic anemia in critically ill children admitted to the intensive care unit. It is important to continue to improve daily practice and to minimize blood volume sampled and/or wasted.

Background: Platelets are the smallest cells in the blood and are involved in the wound healing process. Platelet transfusion is an important part of treating illnesses such as thrombocytopenia and to prevent and stop major bleedings. Platelets for transfusion are received after processing of whole blood through automated or semi-automated systems and pooling of interim platelet units received after the processing. A limit is set for the minimum total estimated platelet yield in a pool to ensure that the final product consists of enough platelets. Aim: The aim of this study was to evaluate the platelet yield index received from Reveos automatic blood processing system by comparing it to the fluorescent flow cytometry method on Sysmex cell counter.  Material and method: Whole blood from 147 donors were processed in the Reveos automated blood processing system into the separate components. All the interim platelet units received a platelet yield index from Reveos. A sample from each interim platelet unit was collected and analyzed on Sysmex in the channel for fluorescent flow cytometry. Result: The difference between the platelet count from the two methods was 45 ±26 x109/unit (p<0,001). Platelet yield index from Reveos was 67 ±17 x109/unit and the platelet count from Sysmex was 112 ±35 x109/unit. The r2 from the scattergram was 0,49. Conclusion: The platelet yield index from Reveos underestimates the platelet yield compared to fluorescent flow cytometry from Sysmex. The limit for the total platelet yield in a pool of interim platelet units could therefore be decreased.

This is a study exploring how robust one feature descriptors, scale invariant feature transform (SIFT), and one feature detector, feature accelerated segmentation test (FAST), are in terms of handling fetoscopic acquired data when mosaicing. Today’s treatment of severe Twin-to-Twin Transfusion Syndrome at Karolinska University Hospital is fetoscopic guided laser occlusion of chorioangiopagous vessels (FLOC) where intersecting blood vessels causing a transfusion (Anastomoses) in between the fetuses are occluded. These blood vessels are located somewhere on the placenta. The fetoscopy includes navigation of a relatively large area where the field of view (FOV) is limited. The limited FOV during the fetoscopy makes it cumbersome to navigate and identify intersected blood vessels. The motivation of this study is to explore ways of dealing with the complications during FLOC by mosaicing an overview of the placenta that can be used as an assisting map to make the procedure safer by improving navigation of the fetoscope and identification of blood vessels during FLOC. In this study, the steps of mosaicing are defined based on mosaicing frameworks to explore how these methods perform in terms of being able to mosaic a map of the placenta. The methods have been tested on non-fetoscopic acquired data as well as fetoscopic acquired data to create a relative measure in between the two. Three tests on non- fetoscopic data were performed to explore how well the methods handled mosaicing of data with distinctive characteristics. The same methods were then tested on unprocessed fetoscopic data before being tested on preprocessed fetoscopic data to see if the results were affected by external preprocessing. The results showed that there were differences in between the methods. SIFT and FAST showed that they have potential of mosaicing non-fetoscopic data of varying extent. SIFT gave an impression of being more robust during all of the tests. SIFT especially performed better during the tests on data with few potential keypoints which is an advantage when speaking of fetoscopic acquired data. SIFT also managed to mosaic a larger area than FAST when mosaicing preprocessed fetoscopic data. Preprocessing the data improved the mosaicing when using SIFT but further improvements are needed. / Denna studie utforskar hur robust en intressepunktsbeskrivare, scale invariant feature transform (SIFT), och enintressepunktsdetektor, feature accelerated segmentation test (FAST), hanterar digitala bilder insamlade av ett fetoskop med syfte att sy ihop dessa till en översiktskarta. Dagens behandling av tvillingtransfusionsyndrom vid Karolinska Universitetssjukhuset är fetoscopic guided laser occlusion of chorioangiopagous vessels (FLOC). Under denna fetoskopi bränner man och därmed blockerar korsande blodkärl som orsakar en transfusion (anastomoses) och obalans i blodomloppet mellan två tvillingfoster. Dessa blodkärl är lokaliserade på placentan. Fetoskopin omfattar navigering av en relativt stor area med ett begränsat synfält. Det begränsade synfältet under FLOC gör det svårt att orientera fetoskopet och identifiera korsande blodkärl som orsakar transfusionen. Syftet med studien är att utforska ett sätt att hantera komplikationerna med FLOC igenom att utforska sätt att skapa en översiktskarta av placentan under FLOC. Denna översiktskarta kan nyttjas under FLOC och därmed göra proceduren säkrare igenom att kartan underlättar orienteringen av fetoskopet och identifiering av orsakande blodkärl. I denna studie är stegen för att skapa en översiktskarta baserade på olika datorseende ramverk för att se hur dessa tillvägagångssätt presterar när det gäller att skapa en översiktskarta. Metoderna för att skapa en översiktskarta har testats på data insamlad med webkamera och data insamlad med fetoskop för att skapa en relativ uppfattning om hur de står sig beroende på indata. Tre tester på data insamlad med webkamera genomfördes för att utforska hur väl metoderna hanterade data med många potentiella intressepunkter, rörelse orsakad av handhållen enhet/kamera, repetitiva mönster, översiktskartor som resulterande i större upplösning, och liten möjlighet att hitta intressepunkter. Samma metoder testades sedan på icke behandlad data insamlad med fetoskop innan den testades på förbehandlad data insamlad med fetoskop för att se förbehandlingensnödvändighet och prestation. Resultaten visar att det är skillnader mellan de två metoderna använda i denna studie, både när det gäller data insamlad med fetoskop och webkamera. SIFT och FAST visar potential av olika grad när det gäller att skapa en översiktskarta med data insamlad av webkamera. SIFT visade sig vara mer robust under alla tester inklusive data insamlad med fetoskop. SIFT presterade speciellt bättre under testen som omfattade få antal möjliga intressepunkter vilket är en fördel när det gäller data insamlad med fetoskop. SIFT lyckades också skapa översiktskartor med större area än FAST när förbehandlad fetoskopisk data testades. När det gäller SIFT så visade resultaten en förbättring när data insamlad med fetoskop förbehandlades men att ytterligare förbättringar är nödvändiga.

Introducción: La transfusión de hemocomponentes constituye una práctica médica importante y frecuente a nivel mundial. El uso apropiado de transfusión de hemocomponentes salva millones de vidas; sin embargo, la prescripción inadecuada de estas transfusiones expone al paciente a riesgos transfusionales y disminuye su disponibilidad para quienes realmente lo necesitan, y más en un hospital de mediana complejidad como el Santa María de Cutervo, donde solo se transfunde concentrado de hematíes. Objetivo: Describir las prescripciones inadecuadas de transfusión de concentrado de hematíes en el hospital del MINSA nivel II-1 Santa María de Cutervo – periodo 2019-2020. Materiales y Métodos: Estudio observacional descriptivo transversal retrospectivo. Se evaluaron 168 solicitudes transfusionales, realizadas entre 2019 y 2020, seleccionadas de manera aleatoria simple. Todas las fichas de la muestra cumplieron con el criterio de inclusión de contar con los datos necesarios para su valoración Se valoraron como inadecuadas aquellas prescripciones que no cumplieron con los criterios establecidos en el “Compendio para el uso clínico de Sangre y Componentes” del Programa Nacional de Hemoterapia y Bancos de Sangre (PRONAHEBAS) – MINSA. Mediante estadística descriptiva se calcularon frecuencias y porcentajes de las prescripciones de transfusión inadecuadas. Resultados: 30,4% de las solicitudes fueron valoradas como inadecuadas. El promedio de hemoglobina de los pacientes transfundidos fue de 7,63 g/dl, el de hematocrito de 23,9%. Gíneco-obstetricia tuvo la mayor frecuencia de prescripciones inadecuadas (30/79). El diagnóstico de mayor frecuencia de prescripción inadecuada fue politraumatismo con un 70,0% (7/10). Los médicos no especialistas fueron los que prescribieron inadecuadamente con más frecuencia. / Introduction: Blood transfusion is an important and frequent medical practice worldwide. The appropriate use of blood component transfusion saves millions of lives. However, the inappropriate prescription of these transfusions exposes the patient to transfusion risks and decreases availability for those who truly need it, especially in a medium-complexity hospital like Santa María de Cutervo, where only packed red blood cells are transfused. Objective: To describe the inappropriate prescriptions of Packed Red Blood Cell transfusion in the MINSA level II-1 Santa María de Cutervo hospital - period 2019-2020. Materials and Methods: A retrospective descriptive cross-sectional observational study was conducted. A total of 168 transfusion requests made between 2019 and 2020 were randomly selected. All the records in the sample met the inclusion criteria of having the necessary data for evaluation. Prescriptions that did not meet the criteria established in the "Compendium for the Clinical Use of Blood and Components" of the National Hemotherapy and Blood Banks Program (PRONAHEBAS) - MINSA were considered inappropriate. Descriptive statistics were used to calculate the frequencies and percentages of inappropriate transfusion prescriptions. Results: 30.4% of the requests were evaluated as inappropriate. The average hemoglobin level of transfused patients was 7.63 g/dl, and the average hematocrit level was 23.9%. Gynecology and obstetrics had the highest frequency of inappropriate prescriptions (30/79). The most frequent diagnosis associated with inappropriate prescription was polytrauma with a rate of 70.0% (7/10). Non-specialist doctors were the ones who prescribed inappropriately most frequently.

Introduction: Whole blood transfusions are indicated for the resuscitation of patients with hemorrhagic trauma. In Sweden, whole blood is stored for 14 days at 4°C. If possible, refrigerated blood is rewarmed to 37°C before transfusion to avoid hypothermia. Platelets contribute to hemostasis and can be activated with several pathways. During storage, shedding of platelet surface receptors takes place. Further research on how platelet storage in whole blood and rewarming before transfusion affect platelets is needed. Aim: The aim was to study how storage in whole blood and rewarming to 37°C affect platelet function, platelet activatability, and changes in platelet surface receptors. Method: Whole blood from two healthy donors was stored for 14 days. During these 14 days, two blood samples were taken on day 0, before and after leukocyte reducing filtration, 1, 3, 7, and 14. One of the two blood samples from each whole blood product was tested at room temperature and the other was rewarmed to 37°C. The blood samples were mixed with antibodies and platelet agonists and analyzed on a flow cytometer. The blood samples were also analyzed on a cell counter. Results: This study shows distinct changes in platelet spontaneous activation, platelet count, and platelet receptor shedding by increased storage time in cold-stored whole blood and even more with rewarming to 37°C. Conclusion: This study shows that during storage, spontaneous platelet activation and shedding of GPIb and GPIIb increases while platelet count decreases. All these factors are likely affecting the platelet function and hemostatic function negatively.

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