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Associação do red blood cell distribution width (RDW) com readmissão e mortalidade de pacientes críticos na unidade de terapia intensivaTonietto, Tiago Antônio January 2016 (has links)
Introdução: O Red blood cell distribution width (RDW) é um preditor de mortalidade em pacientes criticamente enfermos. A associação do RDW na alta da UTI com o risco de readmissão à UTI não é conhecida. Nós fizemos este estudo com o objetivo de investigar a associação entre a presença de anisocitose na alta da UTI e o risco de readmissão à UTI ou óbito inesperado na enfermaria. Métodos: Estudo de coorte retrospectivo que incluiu 813 pacientes com alta da UTI para a enfermaria em um hospital terciário de Porto Alegre, Brasil. A variável de interesse foi o RDW coletado no momento da alta da UTI. Anisocitose foi definida como RDW > 16%. Desfechos de interesse foram readmissão à UTI, óbito inesperado na enfermaria e óbito hospitalar. Hazard ratios (HR) foram estimadas usando o Modelo de Riscos proporcionais de Cox. Variáveis com P < 0.1 na análise univariada foram incluídas na análise multivariada para ajuste. Resultados: Anisocitose na alta da UTI está independentemente associada com readmissão à UTI ou óbito inesperado na enfermaria (HR: 1,682; IC 95% 1,219 – 2,322; P = 0,002). Outras variáveis associadas com este desfecho foram: idade, escore Sequential Organ Failure Assessment (SOFA) na alta da UTI e traqueostomia. Resultados significativos semelhantes foram obtidos após exclusão dos óbitos inesperados na enfermaria (HR: 2,031; IC 95% 1,428 – 2,889; P< 0,001) e para óbito hospitalar (HR: 1,716; IC 95% 1,141 – 2,580; P = 0,01). Conclusões: Anisocitose no momento da alta da UTI está independentemente associada com readmissão à UTI e óbito hospitalar. / Introduction: Red blood cell distribution width (RDW) is a predictor of mortality in critically ill patients. The relationship between the RDW at ICU discharge and the risk of ICU readmission is unknown. The purpose of this study was to investigate the association between the presence of anisocytosis at ICU discharge and the risk of ICU readmission or unexpected death in the ward. Methods: This retrospective cohort study included 813 patients discharged alive from the ICU to the ward in a tertiary hospital in Porto Alegre, Brazil. The target variable was the RDW collected at the time of ICU discharge. Anisocytosis was defined as an RDW > 16%. Outcomes of interest included readmission to the ICU, unexpected death in the ward and in-hospital death. Hazard ratios (HR) were estimated using the Cox proportional hazards model. Variables with a value of P < 0.1 in the univariate analysis were included in the multivariate analysis for adjustment. Results: Anisocytosis at ICU discharge was independently associated with readmission to the ICU or unexpected death in the ward (HR: 1.682; 95% CI 1.219-2.322; P = 0.002). Other variables associated with this outcome included age, Sequential Organ Failure Assessment (SOFA) score at ICU discharge and tracheostomy. Similar significant results were obtained after the exclusion of unexpected deaths in the ward (HR 2.031; CI 1.428 – 2.889; P < 0.001) and for in-hospital deaths (HR 1.716; 95% CI 1.141-2.580; P = 0.01). Conclusions: Anisocytosis at ICU discharge is independently associated with ICU readmission and in-hospital death.
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Lesão de estoque de concentrado de hemácias e a relação com as reações transfusionais febris não hemolíticasSosnoski, Monalisa January 2017 (has links)
Introdução: As transfusões de sangue e as Reações transfusionais (RT) têm tido grande destaque nas discussões e estudos da hemoterapia atual, devido a necessidade e relevância para a prática transfusional e na busca em qualificar as transfusões e refinar a classificação das RT. As reações transfusionais febris não hemolíticas (RTFNH) apresentam um crescente no número de notificações e despertam a necessidade de mais estudos. Durante a estocagem dos hemocomponentes, ocorrem uma série de alterações morfológicas, aumento de potássio (K+) extracelular, hemólise e aumento de hemoglobina (Hb) sobrenadante. Analisar a qualidade e viabilidade do hemocomponente pode nos levar a verificar os fatores preditores de uma RT, procurando minimizar os riscos e selecionar um hemocomponente de melhor qualidade ao paciente. Objetivos: Avaliar potenciais fatores etiológicos na precipitação das RTFNH por meio da mensuração na concentração de sódio (Na+) e K+ no sobrenadante, a contagem leucocitária por mcL, o cultural e o Hematócrito (Ht) e Hb da bolsa de concentrado de hemácias (CH) envolvidas, comparando estes parâmetros em relação a um grupo controle de bolsas de CH. Analisar e comparar o perfil dos pacientes envolvidos com a RTFNH e do grupo controle e, estimar a frequência de culturais coletados positivos e os germes envolvidos. Metodologia: Estudo de caso-controle com seleção de amostras a partir de notificações de suspeita de RTFNH ao Serviço de Hemoterapia de um Hospital Universitário de Porto Alegre - RS, no período de setembro de 2015 a setembro de 2016. O grupo controle foi selecionado a partir da mesma população de bolsas, sendo pareadas por tipagem sanguínea e data de vencimento do hemocomponente, numa proporção de 1:2,1. Resultados: o total incluído foi de 124 bolsas, sendo 39(30,5%) do grupo RT e 85(69,5%) do grupo controle, onde uma série de variáveis foram avaliadas. A média de dias de estocagem das bolsas foi de 10,7(DP=6,7) dias, sendo que no grupo RT 12,1(DP=8,1), foi significativamente maior que no grupo controle 10(DP=5,8) com (P=0,037). Também quando avaliamos as dosagens de Ht as médias verificadas foram de 68,3(DP=7,27), sendo no grupo RT 71(DP=81) e 67(DP=6,5) no grupo controle e, na comparação dos grupos, observamos um P<0,001. Dessa forma, a cada dia a mais de estocagem e, a cada ponto a mais no HT da bolsa, há um aumento na chance de aparecimento de RTFNH. Conclusões: a lesão de estocagem é uma temática importante no momento da oferta de hemocomponentes ao paciente, principalmente aos pacientes em tratamento oncológico de tumores sólidos. A avaliação do HT e do tempo de estocagem da bolsa demonstraram ter relevância estatística e clínica na predição de aparecimento de RTFNH. O manejo de estoque adequado para poder haver essa oferta se faz necessário. Novos estudos serão necessários para verificarmos os mecanismos desencadeantes da RTFNH comparado com o Ht da bolsa e, também estudos relacionados à utilização de pré medicação nas transfusões. / Introduction: Blood transfusions and the transfusion reactions (TR) have had great emphasis in current hemotherapy discussions and studies, due to its importance in transfusion practice and with the aim of qualifying the transfusions and refining TR classifications. The non-hemolytic febrile transfusion reaction (NHFTR) show an increasing number of notifications and arouse the necessity for further studies. During the storage of blood products a series of morphologic alterations occur, such as extracellular potassium (K+) increase, hemolysis and supernatant Hemoglobin (Hb) increase. Analyzing the blood product quality and availability may lead us to verifying predictive factors of a TR, seeking to minimize the risks and select a blood product of a superior quality for the patient. Objective: Evaluate potential etiological factors in the NHFTR precipitation through sodium (Na+) concentration measurement and K+ in the supernatant, the leukocyte count by mcL, the cultural and the Hematocrit (Ht),and Hb of erythrocyte concentrate bag (EC) involved, comparing those parameters in relation to a control group of EC blood bags. Analyze and compare the profile of the patients involved with a NHFTR to the control group and estimate the frequency of positive cultures collected and the germs involved. Methodology: Case-control study with sampling selections from a notification of NHFTR suspicion at a Hemotherapy Service in a College Hospital in Porto Alegre, RS, during the period from September 2015 to September 2016, where the control-group was selected from the same blood bag population, being grouped by blood type and blood product expiry date, in proportion 1:2.1. Results: Were studied 124 blood bags, being 39(39,5%) from the TR group and 85(69,5%) from the control group, where a series of invariables were evaluated. The mean of blood bag storage was 8.5 days, 10,7(PD=6,7) in the TR group and 10(DP=5,8) in the control group, and when compared they showed a P=0.037. Moreover, when we analyzed the Ht dosage, it was verified an mean of 68,3(DP=7,27), in the TR group and 71(DP=81), 67(DP=6,5) in the control group and, comparing both groups, we observed a P=<0.001. Therefore, with each additional storage day and, with each additional point in the Ht bool bag, the chance of NHFTR appearance increases. Conclusions: Storage injury is an important topic at the moment of the offer of blood components to the patient, especially to the ones with ongoing oncological treatments for solid tumors. The HT evaluation and the storage time of the blood bag demonstrate clinical and statistical relevance in the prediction of NHFTR appearance. The management of adequate storage is fundamental for the offer’s availability. Further studies are needed to verify the triggering mechanisms of NHFTR compared to the Ht of the bag, as well as studies associated with the use of premedication in transfusions.
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Interaction et diffusion hydrodynamiques dans une suspension de vésicules et globules rouges / Hydrodynamic interactions and diffusion in vesicle and red blood cell suspensionsSrivastav, Aparna 26 January 2012 (has links)
Blood is a complex suspension of deformable particles, red blood cells, which exhibits a sophisticated dynamics when flowing in the microvasculature. Most of these complex phenomena, non-linear rheology, structuration of the suspension, heterogeneities of the hematocrit distribution, are directly connected to the rich microscopic dynamics of individual red blood cells, and their hydrodynamics interactions. We investigate a few aspects of the dynamics of red blood cells and giant vesicles - a simple model for RBCs. A study on the dynamics of very deflated vesicles, with shapes similar to those of red blood cells, shows that these objects which haven't received a lot of attention so far can exhibit richer than expected dynamics. We then mainly focus on the still unexplored problem of hydrodynamic interactions between vesicles or red blood cells and their consequences at the scale of the suspension. An experimental study of the interaction of two identical vesicles in shear flow shows that there is a net repulsion between the cells that leads to an increase of the distance between vesicles in a suspension. Scaling arguments are proposed for this interaction and a comparison with numerical results is performed and a quantitative estimation of a shear induced diffusion coefficient obtained by averaging the results for pair interactions is found. Finally, we investigate the diffusion of a cloud of red blood cells in Poiseuille flow in order to directly determine diffusion coefficients. The experiment shows that the cloud widens when traveling along the channel with a power law behaviour indicating sub-diffusion. This effect is confirmed by a theoretical analysis of a few limit cases. / Blood is a complex suspension of deformable particles, red blood cells, which exhibits a sophisticated dynamics when flowing in the microvasculature. Most of these complex phenomena, non-linear rheology, structuration of the suspension, heterogeneities of the hematocrit distribution, are directly connected to the rich microscopic dynamics of individual red blood cells, and their hydrodynamics interactions. We investigate a few aspects of the dynamics of red blood cells and giant vesicles - a simple model for RBCs. A study on the dynamics of very deflated vesicles, with shapes similar to those of red blood cells, shows that these objects which haven't received a lot of attention so far can exhibit richer than expected dynamics. We then mainly focus on the still unexplored problem of hydrodynamic interactions between vesicles or red blood cells and their consequences at the scale of the suspension. An experimental study of the interaction of two identical vesicles in shear flow shows that there is a net repulsion between the cells that leads to an increase of the distance between vesicles in a suspension. Scaling arguments are proposed for this interaction and a comparison with numerical results is performed and a quantitative estimation of a shear induced diffusion coefficient obtained by averaging the results for pair interactions is found. Finally, we investigate the diffusion of a cloud of red blood cells in Poiseuille flow in order to directly determine diffusion coefficients. The experiment shows that the cloud widens when traveling along the channel with a power law behaviour indicating sub-diffusion. This effect is confirmed by a theoretical analysis of a few limit cases.
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Interaction hydrodynamique entre deux vésicules dans un cisaillement simple / Hydrodynamic interaction between two vesicles in a simple shear flowGires, Pierre-Yves 18 October 2012 (has links)
Les vésicules sont des bicouches fermées de molécules tensioactives, remplies de liquide, à l'intérieur d'un autre liquide. Leur taille peut être comprise entre dix et 100 microns : elles sont alors dites géantes. Nous nous intéressons à la dynamique de deux de ces objets dans un cisaillement simple, c'est à dire l'écoulement d'un liquide situé entre deux plaques planes se translatant l'une par rapport à l'autre à vitesse et distance constante. Nous commençons par une étude asymptotique, pour des vésicules quasi-sphériques en interaction lointaine. Nous utilisons ensuite un code de calcul basé sur la méthode des éléments de frontière pour étudier le cas de vésicules moins sphériques et plus proches, et comparons les résultats obtenus avec des expériences. Nous présentons enfin comment cette étude peut être utilisée pour prédire certaines propriétés de diffusion d'une suspension de vésicules, dans le régime semi-dilué, où seul le détail des interactions à deux corps est considéré. / Vesicles are closed bilayers of tensioactive molecules, filled with liquid, inside another liquid. Their size can be between 10 and 100 microns : in this case, they are called giant vesicles. We study the dynamic of two of these objects in a simple shear flow, which is the one of a liquid sheared between two walls translating with respect to each other at a constant speed and distance. We begin by an asymptotic study, for quasispherical vesicles in the far field interacting regime. We then use a numerical code based on the boundary element method to study the case of less spherical and closer vesicles, and compare our results with experiments. We finish by presenting how this study can be used to predict some diffusing properties of a sheared suspension of vesicles, in the semidilute regime, where only the details of two body interactions are considered.
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Associação do red blood cell distribution width (RDW) com readmissão e mortalidade de pacientes críticos na unidade de terapia intensivaTonietto, Tiago Antônio January 2016 (has links)
Introdução: O Red blood cell distribution width (RDW) é um preditor de mortalidade em pacientes criticamente enfermos. A associação do RDW na alta da UTI com o risco de readmissão à UTI não é conhecida. Nós fizemos este estudo com o objetivo de investigar a associação entre a presença de anisocitose na alta da UTI e o risco de readmissão à UTI ou óbito inesperado na enfermaria. Métodos: Estudo de coorte retrospectivo que incluiu 813 pacientes com alta da UTI para a enfermaria em um hospital terciário de Porto Alegre, Brasil. A variável de interesse foi o RDW coletado no momento da alta da UTI. Anisocitose foi definida como RDW > 16%. Desfechos de interesse foram readmissão à UTI, óbito inesperado na enfermaria e óbito hospitalar. Hazard ratios (HR) foram estimadas usando o Modelo de Riscos proporcionais de Cox. Variáveis com P < 0.1 na análise univariada foram incluídas na análise multivariada para ajuste. Resultados: Anisocitose na alta da UTI está independentemente associada com readmissão à UTI ou óbito inesperado na enfermaria (HR: 1,682; IC 95% 1,219 – 2,322; P = 0,002). Outras variáveis associadas com este desfecho foram: idade, escore Sequential Organ Failure Assessment (SOFA) na alta da UTI e traqueostomia. Resultados significativos semelhantes foram obtidos após exclusão dos óbitos inesperados na enfermaria (HR: 2,031; IC 95% 1,428 – 2,889; P< 0,001) e para óbito hospitalar (HR: 1,716; IC 95% 1,141 – 2,580; P = 0,01). Conclusões: Anisocitose no momento da alta da UTI está independentemente associada com readmissão à UTI e óbito hospitalar. / Introduction: Red blood cell distribution width (RDW) is a predictor of mortality in critically ill patients. The relationship between the RDW at ICU discharge and the risk of ICU readmission is unknown. The purpose of this study was to investigate the association between the presence of anisocytosis at ICU discharge and the risk of ICU readmission or unexpected death in the ward. Methods: This retrospective cohort study included 813 patients discharged alive from the ICU to the ward in a tertiary hospital in Porto Alegre, Brazil. The target variable was the RDW collected at the time of ICU discharge. Anisocytosis was defined as an RDW > 16%. Outcomes of interest included readmission to the ICU, unexpected death in the ward and in-hospital death. Hazard ratios (HR) were estimated using the Cox proportional hazards model. Variables with a value of P < 0.1 in the univariate analysis were included in the multivariate analysis for adjustment. Results: Anisocytosis at ICU discharge was independently associated with readmission to the ICU or unexpected death in the ward (HR: 1.682; 95% CI 1.219-2.322; P = 0.002). Other variables associated with this outcome included age, Sequential Organ Failure Assessment (SOFA) score at ICU discharge and tracheostomy. Similar significant results were obtained after the exclusion of unexpected deaths in the ward (HR 2.031; CI 1.428 – 2.889; P < 0.001) and for in-hospital deaths (HR 1.716; 95% CI 1.141-2.580; P = 0.01). Conclusions: Anisocytosis at ICU discharge is independently associated with ICU readmission and in-hospital death.
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Lesão de estoque de concentrado de hemácias e a relação com as reações transfusionais febris não hemolíticasSosnoski, Monalisa January 2017 (has links)
Introdução: As transfusões de sangue e as Reações transfusionais (RT) têm tido grande destaque nas discussões e estudos da hemoterapia atual, devido a necessidade e relevância para a prática transfusional e na busca em qualificar as transfusões e refinar a classificação das RT. As reações transfusionais febris não hemolíticas (RTFNH) apresentam um crescente no número de notificações e despertam a necessidade de mais estudos. Durante a estocagem dos hemocomponentes, ocorrem uma série de alterações morfológicas, aumento de potássio (K+) extracelular, hemólise e aumento de hemoglobina (Hb) sobrenadante. Analisar a qualidade e viabilidade do hemocomponente pode nos levar a verificar os fatores preditores de uma RT, procurando minimizar os riscos e selecionar um hemocomponente de melhor qualidade ao paciente. Objetivos: Avaliar potenciais fatores etiológicos na precipitação das RTFNH por meio da mensuração na concentração de sódio (Na+) e K+ no sobrenadante, a contagem leucocitária por mcL, o cultural e o Hematócrito (Ht) e Hb da bolsa de concentrado de hemácias (CH) envolvidas, comparando estes parâmetros em relação a um grupo controle de bolsas de CH. Analisar e comparar o perfil dos pacientes envolvidos com a RTFNH e do grupo controle e, estimar a frequência de culturais coletados positivos e os germes envolvidos. Metodologia: Estudo de caso-controle com seleção de amostras a partir de notificações de suspeita de RTFNH ao Serviço de Hemoterapia de um Hospital Universitário de Porto Alegre - RS, no período de setembro de 2015 a setembro de 2016. O grupo controle foi selecionado a partir da mesma população de bolsas, sendo pareadas por tipagem sanguínea e data de vencimento do hemocomponente, numa proporção de 1:2,1. Resultados: o total incluído foi de 124 bolsas, sendo 39(30,5%) do grupo RT e 85(69,5%) do grupo controle, onde uma série de variáveis foram avaliadas. A média de dias de estocagem das bolsas foi de 10,7(DP=6,7) dias, sendo que no grupo RT 12,1(DP=8,1), foi significativamente maior que no grupo controle 10(DP=5,8) com (P=0,037). Também quando avaliamos as dosagens de Ht as médias verificadas foram de 68,3(DP=7,27), sendo no grupo RT 71(DP=81) e 67(DP=6,5) no grupo controle e, na comparação dos grupos, observamos um P<0,001. Dessa forma, a cada dia a mais de estocagem e, a cada ponto a mais no HT da bolsa, há um aumento na chance de aparecimento de RTFNH. Conclusões: a lesão de estocagem é uma temática importante no momento da oferta de hemocomponentes ao paciente, principalmente aos pacientes em tratamento oncológico de tumores sólidos. A avaliação do HT e do tempo de estocagem da bolsa demonstraram ter relevância estatística e clínica na predição de aparecimento de RTFNH. O manejo de estoque adequado para poder haver essa oferta se faz necessário. Novos estudos serão necessários para verificarmos os mecanismos desencadeantes da RTFNH comparado com o Ht da bolsa e, também estudos relacionados à utilização de pré medicação nas transfusões. / Introduction: Blood transfusions and the transfusion reactions (TR) have had great emphasis in current hemotherapy discussions and studies, due to its importance in transfusion practice and with the aim of qualifying the transfusions and refining TR classifications. The non-hemolytic febrile transfusion reaction (NHFTR) show an increasing number of notifications and arouse the necessity for further studies. During the storage of blood products a series of morphologic alterations occur, such as extracellular potassium (K+) increase, hemolysis and supernatant Hemoglobin (Hb) increase. Analyzing the blood product quality and availability may lead us to verifying predictive factors of a TR, seeking to minimize the risks and select a blood product of a superior quality for the patient. Objective: Evaluate potential etiological factors in the NHFTR precipitation through sodium (Na+) concentration measurement and K+ in the supernatant, the leukocyte count by mcL, the cultural and the Hematocrit (Ht),and Hb of erythrocyte concentrate bag (EC) involved, comparing those parameters in relation to a control group of EC blood bags. Analyze and compare the profile of the patients involved with a NHFTR to the control group and estimate the frequency of positive cultures collected and the germs involved. Methodology: Case-control study with sampling selections from a notification of NHFTR suspicion at a Hemotherapy Service in a College Hospital in Porto Alegre, RS, during the period from September 2015 to September 2016, where the control-group was selected from the same blood bag population, being grouped by blood type and blood product expiry date, in proportion 1:2.1. Results: Were studied 124 blood bags, being 39(39,5%) from the TR group and 85(69,5%) from the control group, where a series of invariables were evaluated. The mean of blood bag storage was 8.5 days, 10,7(PD=6,7) in the TR group and 10(DP=5,8) in the control group, and when compared they showed a P=0.037. Moreover, when we analyzed the Ht dosage, it was verified an mean of 68,3(DP=7,27), in the TR group and 71(DP=81), 67(DP=6,5) in the control group and, comparing both groups, we observed a P=<0.001. Therefore, with each additional storage day and, with each additional point in the Ht bool bag, the chance of NHFTR appearance increases. Conclusions: Storage injury is an important topic at the moment of the offer of blood components to the patient, especially to the ones with ongoing oncological treatments for solid tumors. The HT evaluation and the storage time of the blood bag demonstrate clinical and statistical relevance in the prediction of NHFTR appearance. The management of adequate storage is fundamental for the offer’s availability. Further studies are needed to verify the triggering mechanisms of NHFTR compared to the Ht of the bag, as well as studies associated with the use of premedication in transfusions.
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Formes d’une vésicule en géométrie confinée / Vesicle shapes under confined geometryTrozzo, Roberto 28 May 2015 (has links)
Les vésicules sont gouttes de rayon de quelques dizaines de micromètres, limitées par une membrane lipidique imperméable d'environ 4 nm d'épaisseur, et immergées dans un fluide visqueux externe. Les propriétés spécifiques de la membrane de la vésicule rendent le système très déformable et très contraint dans le même temps. Les vésicules représentent également un modèle simplifié intéressant pour les globules rouges, car ils partagent aussi certains comportements mécaniques similaires.Ce manuscrit s’intéresse à la modélisation d'une vésicule soumise à des contraintes externes d'origine hydrodynamique, dans le régime Stokes et dans des domaines confinés. À partir d'un modèle BEM déjà existant pour des fluides infinis, des méthodes numériques originales sont développés pour faire face au calcul des interactions entre la membrane de la vésicule et les frontières solides. Une attention particulière est accordée à la situation d'une vésicule qui sédimente vers un mur horizontal et une vésicule soumise à un écoulement de Poiseuille dans un capillaire étroit. / Vesicles are drops of radius of a few tens micrometers, bounded by an impermeable lipid membrane of approximately 4 nm thickness, and embedded in an external viscous fluid. The specific properties of the vesicle membrane make the system very deformable and very constrained at the same time. Vesicles represent also an interesting simplified model for red blood cells, since they also share some similar mechanical behaviours.This manuscript deals with the modeling of a vesicle subjected to external stresses of hydrodynamical origin, in the Stokes regime and in confined domains. Starting from an existing BEM model for free space flows, original numerical methods are developed to deal with the computation of interactions between the vesicle membrane and solid boundaries. A particular attention is paid to the situation of a vesicle sedimenting towards a planar wall and a vesicle submitted to a Poiseuille flow in a narrow capillary.
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MARKERS OF OXIDATIVE STRESS AND MATURE RED BLOOD CELL MIRNOME IN CATS WITH DIABETES MELLITUSPierre L. Deshuillers (5929634) 14 January 2021 (has links)
<p>Despite previously accepted dogma, several recently published studies in humans and mice have shown that mature red blood cells (RBCs) contain a pool of microRNAs. Their role is currently uncertain; however, it has been suggested that microRNAs may play a role in cellular communications as they can be transferred from the RBC to endothelial cells or other cells. This thesis investigated the set of differentially abundant microRNAs found in mature RBCs of felines with oxidative stress, using diabetes mellitus as an oxidant stressor. We postulated that individual microRNAs identified in this study, might be valuable targets for future studies, investigating the role specific microRNAs play in the development or progression of diabetes and in the oxidative damage inflicted on the red cell and other cells by this disease.</p><p>The first specific objective of this thesis was to document oxidative stress in diabetic cats. In the absence of validated assays to document the presence of oxidative protein damage in felines, we first evaluated the performance of a commonly used colorimetric assay for measurement of protein carbonyls (PC) in serum and plasma. Although within run variation was acceptable and performed well over a wide range of PC content values, there were severe limitations related to excessive between run-variation, hemoglobin interference, and difficulty of assay performance. Therefore, we developed and validated a new method, using a fluorescent probe. This new assay had good within and between-run variations, a broad analytical range, and was easy and rapid to run. Hemoglobin and triglyceride only affected the results when present at moderate to higher levels. To further evaluate their redox status, free-radical production and oxidative stress were measured in diabetic and healthy, control cats. The presence of oxidative stress was assessed by measurement of the resulting damage to biomolecules, and detection of antioxidant levels. Our data indicated the presence of protein and membrane lipid oxidation in diabetic individuals and suggest that the redox status of the mature RBC was shifted toward an oxidation state.</p><p>In the final chapter of this thesis, we document the presence of an abundant and diverse set of microRNAs in the mature erythrocytes of healthy and diabetic cats. While their function in the mature erythrocyte remains unknown, a difference was found in the microRNA expression patterns of diabetic and healthy cats. Our data uncovered severe bias in the microRNA sequencing such that the expression levels of some microRNAs appeared to be artificially increased and other diminished. The library construction kit used, appeared to be the cause of this bias. Among the 899 erythrocyte microRNAs sequenced, 12 differentially abundant microRNAs were identified in diabetic cats, however only 6 were differentially abundant by RT-qPCR. Let-7b, miR-1692, miR-339, miR-486 and a feline specific microRNA were increased in mature RBCs of diabetic cats, while miR-451 was decreased.</p><p><a></a><a></a>In conclusion, we have shown that diabetic cats have evidence of significant systemic protein and lipid oxidation as well as erythrocytic oxidative stress. The new, fluorescent PC content assay developed and validated herein could serve as useful tool to better understand the role and consequence of oxidative stress in feline diabetes or other diseases and to monitor antioxidant treatment. Further, this test could be readily adapted for use in other domestic species. Additionally, we have shown that a set of erythrocytic microRNAs are differently abundant in diabetic in comparison to healthy cats. The significance of such changes is currently uncertain. It could represent adaptation of erythroid precursors to changes in their environment during erythropoiesis and as such, these microRNAs may be useful biomarkers for altered hematopoiesis. If microRNAs play a role in communication between circulating mature RBCs and cells in their surroundings such as endothelial cells, the possibility that changes in their expression in this host cells may result in pathology is an intriguing possibility that need to be further explored.</p>
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Oxygenation of Solid Tumor Tissue Facilitated by Polymerized Human HemoglobinsBelcher, Donald Andrew 30 September 2019 (has links)
No description available.
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EN JÄMFÖRELSESTUDIE AV PLAST- OCH GLASHEMOCYTOMETRAR FÖR BERÄKNING AV BLODCELLER I VENÖST OCH KAPILLÄRT HELBLODIstrefi, Linda January 2015 (has links)
Hematology-instruments that analyze blood cells can at specific casesbe followed by manual counting with a hemocytometer. The plastic hemocytometer which has a fixed coverslip and is assigned for disposable use, appears to reduce the problems arising from the use of the traditional glass hemocytometer, for instance coverslip-application difficulty and dust particles. Capillary whole blood sampling may be useful for patients at the emergency department and in addition, a smaller volume of blood is taken compared to venous blood sampling. This study will focus on the platelet- and leukocyte count (PLT and WBC) in venous and capillary blood, in order to compare the plastic- and glass hemocytometers with Sysmex XN-2000 (Sysmex Corporation, Kobe, Japan), and verify if capillary whole blood sampling can be used for the measurement of these hematological parameters. 30 subjects donated both capillary- and venous blood samples and these blood samples were analyzed with glass- and plastic hemocytometers with Sysmex XN-2000 as the reference method. The study results showed high correlation between the reference method and plastic hemocytometer at low PLT but were not suitable for WBC-determination. The capillary whole blood showed high correlation to the reference method at WBC-determination, but was unusable at PLT-determination. Glass hemocytometer was closer to the reference method results than plastic hemocytometer was.
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