BACKGROUND: Exercise is a critical treatment modality in persons with Type II Diabetes Mellitus (T2DM), however people with this disease experience chronic fatigue and a decreased exercise capacity, which affects their ability or willingness to participate in physical activity. Studies suggest that this exercise intolerance may be partly due to a reduced exercising muscle blood flow (MBF), and in particular to a reduced ability of red blood cells (RBCs) to evoke ATP-mediated vasodilation and an increase in MBF as they traverse areas of high O2 demand. Additional evidence suggests that caffeine may attenuate this impairment by enhancing the release of ATP from RBCs. HYPOTHESIS: Persons with T2DM would have reduced Forearm Blood Flow (FBF), oxygen consumption (VO2), and exercise tolerance responses to exercise compared to control (CON) subjects, and caffeine would attenuate these impairments. METHODS: T2DM (n = 4) and CON (n = 4) participants performed rhythmic forearm handgrip exercise at an intensity equivalent to 17.5 kg until “task failure” or 20 minutes of exercise was reached, after having consumed either a caffeine (5mg/kg; Caff) or placebo (Pl) capsule. FBF (Doppler and Echo ultrasound of the brachial artery), VO2 and lactate efflux (deep venous blood sampling), forearm vascular conductance (FVK), mean arterial pressure (MAP) and heart rate (HR) were quantified for each minute of exercise. RESULTS: Steady state FBF was similar across groups and treatment conditions (mean ± SE ml/min; CONCaff 553.80 ± 82.35, CONPl 583.42 ± 112.62, T2DMCaff 523.33 ± 105.39, T2DMPl 569.08 ± 134.20, NS), and this was due to similar MAP and FVK (across groups and treatment conditions, NS). VO2 and Time to Task Failure (TTF) were not different between groups and treatment conditions (NS), although TTF tended to be improved with caffeine versus placebo (10.00 ± 2.02 vs 8.24 ± 1.79 min, P=0.295). There was a strong positive relationship between FBF and TTF (r2=0.763; P=0.005). CONCLUSIONS: In the exercise model utilized, persons with T2DM do not have impaired cardiovascular responsiveness or reduced exercise tolerance, and caffeine does not provide any benefit. Differences in exercising MBF may be an underlying mechanism regarding differences in exercise tolerance. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-09-16 16:19:42.537

Background: Dietary fat intake particularly of omega-3 and omega-6 fatty acids play an important role in growth and development and influence the risk of nutrition related non communicable diseases. These dietary intakes are reflected in the red blood cell (RBC) fatty acid profile. Aim: The aim of this study was to assess the fatty acid profile (%) of red blood cell membrane phospholipids in relation to the dietary intake of South African children aged 2 to 5 years, and of their mothers/caregivers from three communities, each with distinct dietary patterns. Method: In this cross-sectional observational study, approximately 105 children, aged: 2-5 years and their mother/caregivers were selected from three different geographical areas. These included; the urban community of De Aar (n=105), the urban coastal community Ocean View (n=93) and the rural community of Sekhukhune District (n=104). The red blood cell membrane total phospholipid fatty acid profile was determined by gas chromatography. A 24-hour dietary recall was done for each child and mother/caregiver as well as a socio-demographic questionnaire answered by each mother/caregiver. The mean and standard deviations of the RBC fatty acids were determined and compared through an analysis of variance (ANOVA) test followed by a Bonferroni post hoc test. Age and gender were controlled for in the children and age was controlled for in the mothers/caregivers. The median dietary intake (quartile range) was compared between communities by a Kruskal-Wallis test. The relationship between RBC membrane total phospholipid fatty acid profile and dietary fatty acid intake was done by stratifying the data for the three groups combined into tertiles according to RBC fatty acid profile and comparing the median (quartile range) of the dietary fatty acid intake in the different strata. Results: In the children, the total dietary fat, SFA and PUFA and omega-3 intake of De Aar (34.2%, 11.9%, 5.9% and 0.2% of energy, respectively) and Ocean View (33.0%, 11.2%, 7.4% and 0.2% of energy, respectively) was significantly different to Sekhukhune (19.9%, 6.5%, 3.0% and 0.1% of energy, respectively). Eicosaipentanoic (EPA) and docosahexaenoic (DHA) and α-linolenic acid (ALA) mean intake in children in all three sites was lower than recommended. In children from De Aar the RBC membrane total phospholipids contained significantly higher SFA and trans-fat percentages, while children in Sekhukhune District had significantly higher PUFA, omega-6 and omega-3 percentages. The linoleic acid (LA) profile in children from Ocean View was significantly higher than in those from De Aar and Sekhukhune District. The mother/caregivers’ dietary fat intake of total fat, SFA, PUFA and trans-fat was significantly higher in De Aar (31.7%, 10.5%, 6.3% and 0.2% of energy respectively) and Ocean View (37.4%, 12.1%, 8.5% and 0.59% of energy respectively) in comparison to Sekhukhune District (15.7%, 3.0%, 3.2% and 0.02% energy respectively). PUFA intakes were significantly higher in Ocean View (8.5% of energy). EPA, DHA and ALA dietary intakes were lower than recommended. The mother/caregiver’s RBC membrane total phospholipid SFA percentage was significantly higher in mothers/caregivers from De Aar and Ocean View whereas those from Sekhukhune District had significantly higher PUFA and omega-3 percentage. Conclusion: Differences particularly between the urban areas of De Aar and Ocean View and the rural area of Sekhukhune District were observed in dietary fat intake which was reflected in the red blood cell membrane total phospholipid fatty acid profile for children and mother/caregivers. Dietary omega-3 fatty acid intake was low in both children and mother/caregivers from all three study sites and is of concern. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

Background: Dietary fat intake particularly of omega-3 and omega-6 fatty acids play an important role in growth and development and influence the risk of nutrition related non communicable diseases. These dietary intakes are reflected in the red blood cell (RBC) fatty acid profile. Aim: The aim of this study was to assess the fatty acid profile (%) of red blood cell membrane phospholipids in relation to the dietary intake of South African children aged 2 to 5 years, and of their mothers/caregivers from three communities, each with distinct dietary patterns. Method: In this cross-sectional observational study, approximately 105 children, aged: 2-5 years and their mother/caregivers were selected from three different geographical areas. These included; the urban community of De Aar (n=105), the urban coastal community Ocean View (n=93) and the rural community of Sekhukhune District (n=104). The red blood cell membrane total phospholipid fatty acid profile was determined by gas chromatography. A 24-hour dietary recall was done for each child and mother/caregiver as well as a socio-demographic questionnaire answered by each mother/caregiver. The mean and standard deviations of the RBC fatty acids were determined and compared through an analysis of variance (ANOVA) test followed by a Bonferroni post hoc test. Age and gender were controlled for in the children and age was controlled for in the mothers/caregivers. The median dietary intake (quartile range) was compared between communities by a Kruskal-Wallis test. The relationship between RBC membrane total phospholipid fatty acid profile and dietary fatty acid intake was done by stratifying the data for the three groups combined into tertiles according to RBC fatty acid profile and comparing the median (quartile range) of the dietary fatty acid intake in the different strata. Results: In the children, the total dietary fat, SFA and PUFA and omega-3 intake of De Aar (34.2%, 11.9%, 5.9% and 0.2% of energy, respectively) and Ocean View (33.0%, 11.2%, 7.4% and 0.2% of energy, respectively) was significantly different to Sekhukhune (19.9%, 6.5%, 3.0% and 0.1% of energy, respectively). Eicosaipentanoic (EPA) and docosahexaenoic (DHA) and α-linolenic acid (ALA) mean intake in children in all three sites was lower than recommended. In children from De Aar the RBC membrane total phospholipids contained significantly higher SFA and trans-fat percentages, while children in Sekhukhune District had significantly higher PUFA, omega-6 and omega-3 percentages. The linoleic acid (LA) profile in children from Ocean View was significantly higher than in those from De Aar and Sekhukhune District. The mother/caregivers’ dietary fat intake of total fat, SFA, PUFA and trans-fat was significantly higher in De Aar (31.7%, 10.5%, 6.3% and 0.2% of energy respectively) and Ocean View (37.4%, 12.1%, 8.5% and 0.59% of energy respectively) in comparison to Sekhukhune District (15.7%, 3.0%, 3.2% and 0.02% energy respectively). PUFA intakes were significantly higher in Ocean View (8.5% of energy). EPA, DHA and ALA dietary intakes were lower than recommended. The mother/caregiver’s RBC membrane total phospholipid SFA percentage was significantly higher in mothers/caregivers from De Aar and Ocean View whereas those from Sekhukhune District had significantly higher PUFA and omega-3 percentage. Conclusion: Differences particularly between the urban areas of De Aar and Ocean View and the rural area of Sekhukhune District were observed in dietary fat intake which was reflected in the red blood cell membrane total phospholipid fatty acid profile for children and mother/caregivers. Dietary omega-3 fatty acid intake was low in both children and mother/caregivers from all three study sites and is of concern. / MSc (Nutrition), North-West University, Potchefstroom Campus, 2014

The ability to measure the oxygen saturation, oximetry, of retinal blood both non-invasively and in-vivo has been a goal of eye research for years. Retinal oximetry can in principle be achieved from the measurement of the reflectance spectrum of the ocular fundus. Oximetry calculations are however complicated by the scattering of red blood cells, the different pathways of light through blood and the ocular tissues that light interacts with before exiting the eye. The goal of this thesis was to investigate the influence of red blood cell scattering for different light paths relevant to retinal oximetry. Results of in-vitro whole blood experiments found calculated oxygen saturation differences between blood samples measured under different retinal light paths, and these differences did not depend on the absorbance path length. We also showed that the calculated oxygen saturation value determined by a multiple linear regression Beer-Lambert absorbance model depended on the wavelength range chosen for analysis. The wavelength dependency on the calculated oxygen saturation value is due in part to the correlation that exists between the oxyhaemoglobin and deoxyhaemoglobin extinction coefficient spectra and to errors in the assumptions built into the Beer-Lambert absorbance model. A wavelength region with low correlation between the oxyhaemoglobin and deoxyhaemoglobin extinction coefficients was found that is hypothesized to be a good range to calculate oxygen saturation using a multiple linear regression approach.

La capacité des globules rouges à modifier leur forme en fonction de conditions externes spécifiques représente une propriété fondamentale permettant aux cellules de traverser des capillaires de diamètres plus petits que leur propre diamètre. L’ektacytométrie est une technique utilisée pour mesurer la déformabilité des globules rouges en exposant un échantillon très dilué de sang à des contraintes de cisaillement et en mesurant l’élongation resultante des globules par l'analyse de la figure de diffraction laser. Ce travail contribue à la conception et l’évaluation d’un nouveau dispositif de diagnostic basé sur la méthode microfluidique d'ektacytométrie à gradient osmolaire. Elle permet de mesurer la déformabilité d'une population de globules rouges (RBC), en fonction de l'osmolalité de milieu. Cette mesure permet un diagnostic différentiel d'un certain nombre de troubles de globules rouges présentant des symptômes similaires. Elle permet également de suivre les effets de certains traitements. Des aspects théoriques qui s’appuient sur les équations des écoulements et une preuve de principe sont discutés. Cette nouvelle technique ouvre la possibilité de construire un instrument simple et peu encombrant, décrit dans ce travail, ne nécessitant qu'un prélèvement de sang au bout du doigt / The ability of red blood cells (RBC) to change their shape under varying conditions is a crucial property allowing these cells to go through capillaries narrower than their own diameter. Ektacytometry is a technique for measuring deformability by exposing a highly diluted blood sample to shear stress and evaluating the resulting elongation in RBC shape using a laser diffraction pattern. This work contributes to the design and evaluation of a new diagnostic technique based on osmotic scan ektacytometry, using a microfluidic method. It allows the measurement of deformability of an RBC population, as a function of varying medium osmolality. This measurement makes possible a differential diagnosis for any one of a number of RBC disorders presenting similar symptoms. It also permits the physician to follow the effects of treatments. Both theoretical aspects based on flow equations and a proof of principle are discussed. This new technique opens up the possibility of building a simple, small footprint instrument described in this work that can be used with finger prick amounts of blood

SANTIAGO, Thiago de Melo. Estudo de propriedades mecânicas e morfológicas de hemácias em indivíduos portadores de anemia falciforme por microscopia de força atômica. 2012. 117 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-16T20:53:51Z No. of bitstreams: 1 2012_dis_tmsantiago.pdf: 3674927 bytes, checksum: 924d0c4a244e4eb06381e66ed8849abf (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-20T20:55:23Z (GMT) No. of bitstreams: 1 2012_dis_tmsantiago.pdf: 3674927 bytes, checksum: 924d0c4a244e4eb06381e66ed8849abf (MD5) / Made available in DSpace on 2015-10-20T20:55:23Z (GMT). No. of bitstreams: 1 2012_dis_tmsantiago.pdf: 3674927 bytes, checksum: 924d0c4a244e4eb06381e66ed8849abf (MD5) Previous issue date: 2012 / Nesse trabalho, propomos o uso da Microscopia de Força Atômica para a investigação das propriedades mecânicas e morfológicas dos eritrócitos de pacientes com anemia falciforme, visando propor que parâmetros físicos tais como curvatura, rugosidade, elasticidade e viscosidade, possam ser utilizados na investigação laboratorial dessa doença. Em cada etapa experimental, foram medidas as propriedades mecânicas de cinco células por indivíduo. Nessa pesquisa analisamos o sangue de cinco pacientes em tratamento no Centro de Hematologia e Hemoterapia do Estado do Ceará (HEMOCE) e, como controle, cinco doadores sadios voluntários. Os resultados indicam a diminuição da rugosidade da superfície citoplasmática da membrana eritrocitária dos doadores com a doença. A análise de elasticidade das hemácias dos pacientes com anemia indica que módulo de Young, em média, é cerca de três vezes maior do que o módulo encontrado nas hemácias de doadores sadios. A análise da histerese de curvas de forças sobre os eritrócitos revela que as hemácias contendo a hemoglobina anormal dissipam menos energia e, portanto, são mais viscosas que as hemácias advindas de doadores sadios.

Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2016. / Biochemical and haematological changes occur in red blood cellular products during the recommended storage period of 35 to 42 days at 1°C to 6°C. The restriction of the sodium/potassium pump at specified temperatures result in low intracellular potassium ion levels while an increase in sodium ion levels are observed and acidosis occurs as a result of low pH concentrations due to glucose consumption. Structural and morphological changes occur such as the release of free haemoglobin, lactate dehydrogenase and potassium into the supernatant causing the formation of spheroechinocytes and osmotic fragility. All these factors negatively impact the rheological properties of blood. These changes that transpire in the red cells during the storage period are referred to as “storage lesions”. Transfusion-associated graft versus host disease is an immunological and often fatal adverse transfusion reaction with gamma irradiation of cellular blood products used as a preventative measure. Gamma irradiation exacerbates storage lesions and of particular concern has been the increased potassium levels resulting in neonatal and infant hyperkalaemia. The storage lesions occurring in non-irradiated red blood cellular products are well documented although the literature regarding its irradiated counterparts has been less studied. A study of this nature has not previously been done in Cape Town, South Africa.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Nesse trabalho, propomos o uso da Microscopia de ForÃa AtÃmica para a investigaÃÃo das propriedades mecÃnicas e morfolÃgicas dos eritrÃcitos de pacientes com anemia falciforme, visando propor que parÃmetros fÃsicos tais como curvatura, rugosidade, elasticidade e viscosidade, possam ser utilizados na investigaÃÃo laboratorial dessa doenÃa. Em cada etapa experimental, foram medidas as propriedades mecÃnicas de cinco cÃlulas por indivÃduo. Nessa pesquisa analisamos o sangue de cinco pacientes em tratamento no Centro de Hematologia e Hemoterapia do Estado do Cearà (HEMOCE) e, como controle, cinco doadores sadios voluntÃrios. Os resultados indicam a diminuiÃÃo da rugosidade da superfÃcie citoplasmÃtica da membrana eritrocitÃria dos doadores com a doenÃa. A anÃlise de elasticidade das hemÃcias dos pacientes com anemia indica que mÃdulo de Young, em mÃdia, à cerca de trÃs vezes maior do que o mÃdulo encontrado nas hemÃcias de doadores sadios. A anÃlise da histerese de curvas de forÃas sobre os eritrÃcitos revela que as hemÃcias contendo a hemoglobina anormal dissipam menos energia e, portanto, sÃo mais viscosas que as hemÃcias advindas de doadores sadios.

Segundo a legislação brasileira e normas internacionais, os concentrados de hemácias (CH) devem ser mantidos sob controle rigoroso de temperatura, armazenados de 2 a 6°C e transportados de 1 a 10°C, por até 24 horas. Entretanto, não existem evidências científicas de que estes valores sejam relevantes para manutenção de qualidade, segurança e viabilidade dos CH. O objetivo deste trabalho foi monitorar parâmetros laboratoriais in vitro em dois tipos de CH (CPDA-1, preparado pela metodologia do plasma rico em plaquetas e em SAGM preparado pelo buffy-coat), no decorrer de condições normais de armazenamento e em temperaturas de transporte inadequadas. O trabalho foi executado em três etapas. Na primeira etapa, foram estabelecidos os valores de referência para os dois tipos de CH armazenados em condições normais, através de testes laboratoriais semanais para determinação de hematócrito, hemoglobina total, hemoglobina plasmática, grau de hemólise, glicose, lactato, desidrogenase lática e potássio. Na segunda etapa, amostras de CH foram submetidas a temperaturas entre -2°C e +1°C, ou entre 11 e 15°C, por um período de 6 horas ou 24 horas, no 14º dia de armazenamento. Na terceira etapa os CH foram expostos a condições de estresse extremo, submetendo-os a temperaturas entre -2°C e +1°C ou entre 22°C e 25°C, por período de 48 horas. Os resultados dos testes laboratoriais das segunda e terceira etapas foram comparados com controles e aos valores de referência da primeira etapa. Nas unidades de CH em CPDA-1 foram encontrados valores significativamente mais elevados de potássio, hemoglobina livre, grau de hemólise, lactato e LDH do que nos CH em SAGM, enquanto que a concentração de glicose foi muito mais baixa em CH-CPDA1. Na 2ª etapa, exposições por até 24 horas em temperaturas de até - 2°C ou até 15°C não causaram diferenças significativas nas dosagens de hemoglobina livre, grau de hemólise, glicose, lactato, LDH e potássio quando comparados aos controles. Amostras de CH-CPDA1, quando avaliadas imediatamente após período de 48 horas de exposição, apresentaram resultados de glicose superiores aos controles quando submetidas a -2°C e inferiores ao controle quando a 25°C. Exposições por até 48 horas em temperaturas de até -2°C ou até 25°C não causaram diferenças significativas na hemoglobina livre, grau de hemólise, lactato, LDH e potássio quando comparados aos controles, nos dois tipos de CH. Nesse trabalho foram elaborados perfis padrão de parâmetros laboratoriais para dois tipos de CH. Estes perfis padrão constituirão uma ferramenta de grande utilidade para controle de qualidade e monitoramento das lesões de armazenamento em bolsas de CH produzidas na Fundação HEMOMINAS. Nossos resultados demonstraram que bolsas dos dois tipos de CH submetidas a temperaturas de - 2°C ou 14°C por períodos inferiores a 24 horas não apresentam alterações significativas nos parâmetros laboratoriais avaliados in vitro e permitiram algumas elaboramos recomendações práticas e importantes para serviços de hemoterapia. Entretanto, ainda não existem ainda evidências suficientes na literatura para modificação das normas de temperatura e tempo de transporte atualmente preconizadas pela legislação nacional e internacional. / The Brazilian legislation and international guidelines require that red blood cell concentrates (RBC) are kept under a strict temperature control, stored between 2 and 6°C and transported between 1 and 10°C for up to 24 hours. Nevertheless, there is no scientific evidence that these values are relevant to maintain RBC quality, safety and viability. This study was performed in order to monitor in vitro laboratorial variables of two different RBC types (CPDA-1, prepared using the platelet-rich plasma methodology, or SAGM, prepared using the buffy-coat) stored under normal conditions or under inadequate temperatures during transportation. The study had three phases. In the first phase, weekly laboratorial tests were performed to establish the reference values of hematocrit, total hemoglobin, plasma hemoglobin, rate of hemolysis, glucose, lactate, lactic acid dehydrogenase (LDH) and potassium, for each of the RBC types stored under normal conditions. In the second phase, RBC samples were submitted to temperatures between -2°C and +1°C, or between 11 and 15°C, for 6 hours or 24 hours, on the 14th storage day. Laboratorial test results were compared to a control group (2-6°C) and to the reference values established in the 1st phase. In the third phase, RBCs were exposed to extreme stress, i.e., temperatures between -2°C and +1°C or between 22°C and 25°C, for 48 hours, and the laboratory test results were compared to a control group. CPDA1-RBC had higher levels of potassium, free hemoglobin, rate of hemolysis, lactate and LDH compared to SAGM-RBC, whereas glucose was significantly lower in CPDA1. In the second phase, exposure for up to 24 hours in temperatures until -2°C or 15°C had no effect on free hemoglobin, rate of hemolysis, glucose, lactate, LDH and potassium when compared to control. CPDA1 samples right after the 48-h exposure had higher glucose levels than controls when kept at -2°C and lower than control if exposed to 25°C. Exposures up to -2°C or 25°C for up to 48 hours had no effect on free hemoglobin, rate of hemolysis, lactate, LDH and potassium when compared to control groups, both for CPDA1-RBC and SAGM-RBC. In this study, it was established standards for laboratory analyses for two different RBC types. Such standards will comprise valuable and useful tools for the quality control and monitoring of storage lesions of RBC units produced by Fundação HEMOMINAS. Our results demonstrate that units from both RBC types submitted to -2°C or 14°C for up to 24 hours had no significant changes in in vitro laboratory variables and allow some practical and important recommendations for hemotherapy services. Nevertheless, there are not enough evidences in the literature to support changes in the current guidelines for transportation recommended by national and international legislation.

The ability to measure the oxygen saturation, oximetry, of retinal blood both non-invasively and in-vivo has been a goal of eye research for years. Retinal oximetry can in principle be achieved from the measurement of the reflectance spectrum of the ocular fundus. Oximetry calculations are however complicated by the scattering of red blood cells, the different pathways of light through blood and the ocular tissues that light interacts with before exiting the eye. The goal of this thesis was to investigate the influence of red blood cell scattering for different light paths relevant to retinal oximetry. Results of in-vitro whole blood experiments found calculated oxygen saturation differences between blood samples measured under different retinal light paths, and these differences did not depend on the absorbance path length. We also showed that the calculated oxygen saturation value determined by a multiple linear regression Beer-Lambert absorbance model depended on the wavelength range chosen for analysis. The wavelength dependency on the calculated oxygen saturation value is due in part to the correlation that exists between the oxyhaemoglobin and deoxyhaemoglobin extinction coefficient spectra and to errors in the assumptions built into the Beer-Lambert absorbance model. A wavelength region with low correlation between the oxyhaemoglobin and deoxyhaemoglobin extinction coefficients was found that is hypothesized to be a good range to calculate oxygen saturation using a multiple linear regression approach.