Thesis (doctoral)--Freie Universität Berlin, 1979.

Hematocrit and hematocrit regulation have the potential to affect developing embryos. To examine the ability of chicken embryos at day 15 to regulate hematocrit, they were subjected to either repeated saline injections (5% of total blood volume) or repeated blood removal (5% of total blood volume). Embryos showed an ability to maintain hematocrit (~20%) despite blood volume increases up to 115% of initial blood volume. Embryos were not able to maintain hematocrit in the face of dramatic blood volume loss. Oxygen consumption of embryos could be affected by their level of hematocrit. To examine this, chicken embryos at day 15, 16, and 17 of incubation were given a high hematocrit (~50-60%) sample of blood (400 μl) to artificially increase the hematocrit of the embryos (~10-12%). Despite the increase in oxygen availability, when monitored over a period of six hours, embryos showed no difference (0.36 ± 0.01 (ml O2 - min-1- egg-1) in metabolism from baseline measurements at day 15, 16 and 17.

Previously, it was reported that the morphological changes (pseudopod projection) that circulating neutrophils adopt due to cell activation raises peripheral vascular resistance by disrupting microvascular rheology. Studies utilized murine muscle preparations to link neutrophil pseudopod formation to cell activation and a viscous impact on hemodynamic resistance. But because of the complexity associated with the organization of the vasculature and microvasculature in tissues, it was unclear whether the effects of neutrophil activation on hemodynamic resistance were associated with the macro-/micro- circulation. This research describes an in vitro analysis using viscometry and microvascular network mimics (microporous membranes) to assess the rheological impact of pseudopods on capillary-like flow. Suspensions of neutrophil-like HL-60 promyelocytes (dHL60’s) and human neutrophils, stimulated with 10 nM fMLP were used, with/without hematocrit. Stimulation of dHL60s or human neutrophils with fMLP altered their flow behavior, which was detected as an increase in solution viscosity. Addition of hematocrit negated the effect of neutrophil activation on suspension viscosity. Moreover, cell activation increased the resistance of microporous membranes to flow of neutrophil suspensions with addition of hematocrit exacerbating this effect. Combined, the results of this study provided evidence that activated neutrophils influence microscale flow resistance via a rheological impact.

Thesis (M.S.M.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Although testosterone therapy consistently increases hematocrit levels across numerous clinical trials, the factors that affect the relationship between testosterone therapy and on-treatment hematocrit are poorly understood. Here, the effect of testosterone on hematocrit levels was contrasted across subgroups of men from 2 randomized, placebo-controlled trials involving testosterone gel therapy: the Testosterone and Erectile Dysfunction (TED; ClinicalTrials.gov # NCT00512707; n = 130) and the Testosterone in Older Men (TOM; ClinicalTrials.gov # NCT00240981; n = 152). Hematocrit elevations with testosterone therapy were greater among men self-identifying as white (difference between white and black men 2.32, 95% CI 1.03, 3.61; P = 0.0005). Compliance to therapy also modified the effect of testosterone on hematocrit (difference between participants with 99 to 100% vs. 21 to 87% compliance with therapy 1.83%; 95% CI 0.23, 3.42; P = 0.026). On-treatment hematocrit levels were greater among older men (difference between 75 to 87 and 50 to 57 years 1.66%; 95% CI 0.08, 3.24; P = 0.039) and men with hypertension (difference between men with and without hypertension 1.31; 95% CI 0.14, 2.48; P = 0.028). On-treatment hematocrit levels were smaller among men who smoke(treatment effect difference between smokers and non-smokers -1.22%; 95% CI -2.80, 0.36; P = 0.129), men with Chronic Obstructive Pulmonary Disorder (difference - 2.92%; 95% CI -6.41, 0.58; P = 0.101), and those with sleep apnea (difference - 0.88; 95% CI -2.93, 1.16; P = 0.40), however the numbers of men reporting these characteristics are too small to draw strong conclusions. In conclusion, greater increases in hematocrit levels with testosterone therapy may associate with greater compliance, having hypertension, advanced age, and white race. / 2031-01-01

Despite the major reproductive advances in the livestock industry, prenatal embryonic loss is still one of the major issues that causes substantial economic loss. While there are many tests available to determine pregnancy soon after maternal recognition of pregnancy, most of the prenatal losses are undetectable because it occurs before then. Based on previous research we hypothesized that increased plasma volume around the time of estrus will increase the survivability of the embryo at early stages of gestation. However, our findings indicate that hematocrit levels are not a consistent measurement in determining successful pregnancies.

Blood is one of the most common and important types of physical evidence present at a crime scene. When liquid blood is acted upon by external physical forces, that blood is often distributed through the air in the form of droplets, with bloodstains and bloodstain patterns deposited on adjacent surfaces. Using the mathematical relationship that exists between the blood droplet and resultant bloodstain’s length and width ratio, the angle at which the blood droplet impacted the receiving surface can be determined. Using this relationship, it becomes possible for Bloodstain Pattern Analysts to determine the three dimensional Region of Origin for the blood source from which the bloodstains under examination have originated. A Bloodstain Pattern Analyst performs angle of impact calculations from bloodstains for the purpose of making a three dimensional determination of blood source Region of Origin. The reliability of that determination is based on an assumption that one of the most important biological properties of blood; the amount of red blood cells or hematocrit value, has no influence over the length to width ratio of a bloodstain. As a consequence the Impact angle = arcsine [width/length] calculation has been assumed accurate regardless of the 'unknown' hematrocrit value. This thesis investigated the effect of the hematocrit value on the angle of impact calculation and thus the ability to determine the three dimensional blood source Region of Origin. Bloodstains were created by releasing a series of 18µL droplets, with ten different hematocrit values, onto a ceramic tile at four different angles. The resultant bloodstain length and width was measured and impact angle calculated. Evaluation of the research data shows that the hematocrit value significantly affects the bloodstains length and width. However, it is apparent that there is close agreement between the known and calculated impact angles irrespective of the hematocrit value.

A prospective observational study was conducted to investigate the effects of nutrition and related factors on the outcome of pregnancy in nulliparous African American women 16-35 years of age. Blood samples from a subset of these subjects were taken during the first (1st), second (2nd) and third (3rd) trimesters of pregnancy and at delivery. Cord blood samples were also collected at delivery. Levels of selected biochemical variables including serum ferritin, vitamin B12 and folate as well as whole blood folate, and selected hematologic indices were determined and correlated with pregnancy outcome variables. During the second trimester of pregnancy, values for hematocrit and hemoglobin were less than 30% and 11 g/dL, respectively, in 16% and 30% of the participants, respectively. Serum and whole blood (WB) folate increased sequentially during pregnancy. Cord concentrations of serum folate were significantly higher than maternal concentrations at delivery (P<0.05). Serum ferritin declined significantly from 36±5.6 ng/ml in the first trimester to 17±1.5 ng/ml during the 3rd trimester (P<0.05), and returned to the 2nd trimester level (26±2.0 ng/ml) at delivery. Second trimester WB folate was positively related to birth weight (R2=0.21), while gestational age was inversely correlated with 3rd trimester vitamin B12 (R2=0.34). These data suggest that vitamin B12 and folate play an important role in the outcome of pregnancy in this population.

No description available.

Bats are the only mammals capable of powered flight. In flight, bats consume up to 20 times more oxygen per hour than under basal conditions. This is twice the increase reported for running mammals of the same body sizes. Birds are the only other group of vertebrate capable of powered flight. By plotting morphological and physiological parameters against body mass for bats, terrestrial mammals, and birds, we can observe to what extent these parameters permit high rates of oxygen delivery necessary for flight. In this study we analyzed basal metabolic rate, heart mass, and hematocrit, and compared how differently they scale in the afore-mentioned groups. We found that larger heart masses are associated with the ability to fly; hematocrit values for birds change markedly with body size, while those for mammals and bats are nearly independent of body size; and that BMR scales differently in all three groups.

Esta dissertação tem como objetivo avaliar: o efeito da suplementação de Fe, a partir de duas fontes, em dietas para matrizes Cobb 500, no período de 40 a 67 semanas; os efeitos desta suplementação na coloração da casca e na progênie. No período experimental com as reprodutoras, o arranjo foi completamente casualizado com 3 suplementações: (1) 50 ppm de Sulfato ferroso (Fe-S), (2) 50 ppm de Fe-S + 40 ppm de complexo ferro-aminoácido (Fe-AA) e (3) 40 ppm de Fe-AA, onde foram mensuradas a produção de ovos, coloração da casca e qualidade dos ovos. Para avaliação da eclodibilidade, parâmetros sanguíneos e desempenho da progênie ovos da 65ª semana foram classificados em (I) claros e (II) escuros antes de serem incubados, em um arranjo fatorial 3 x 2. As amostras de sangue foram coletadas após eclosão e o desempenho foi medido de 1 a 34 dias de idade e em três fases: pré-inicial (1-7 d) inicial (8-21 d) e crescimento (22-35 d). O rendimento de carcaça foi medido aos 35 dias. A suplementação com Fe não teve efeito na produção, qualidade e coloração das cascas dos ovos (P>0,05). Não houve interação (P>0,05) entre os fatores,mas efeitos da suplementação e coloração das cascas foram observados. A suplementação 3 foi superior a 1 (P<0,05) porém ambas foram iguais à 2, para fertilidade dos ovos e eclodibilidade destes. Não foi observado efeito de coloração de casca para tais respostas. A hemoglobina e hematócrito não foram afetados por nenhum dos fatores. Para o ganho de peso houve influência da suplementação e da casca, onde no acumulado de 1 a 35 dias a resposta da 3 foi superior a da 2 e este superior a da 1, da mesma forma, II foi superior à I (P<0,05). A conversão alimentar foi afetada pela cor da casca nas fases inicial e crescimento, onde, em ambas, cascas escuras resultaram em melhores índices (P>0,05). O filé de peito foi o único corte comercial afetado pela suplementação, onde a 3 foi melhor que a 2 e a 1 (P>0,05) em relação à carcaça. O rendimento de carcaça e demais cortes comerciais não foram afetados pelos tratamentos. Em conclusão, a suplementação de dietas para matrizes pesadas com Fe-AA resulta em maior fertilidade e eclodibilidade dos ovos; na progênie, melhora o desempenho e rendimento de filé de peito. Além disso, ovos de casca escura proporcionam pintos com desempenho zootécnico superior. / This dissertation has the objective evaluate the effect of iron supplementation, from two sources, in diets for Cobb 500 broiler breeders, from 40 to 67 weeks; the effects of supplementation on eggshell color and progeny. In the broiler breeder experimental period, the trial was completely randomized with 3 supplementations: (1) 50 ppm of ferrous sulfate (Fe-S), (2) 50 ppm of Fe-S + 40 ppm of iron amino acid complex (Fe-AA) and (3) 40 ppm Fe-AA, where measured the egg production, quality and eggshell color. To evaluate the hatchability, blood variables and performance of progeny, eggs from the 65th week were classified in (I) pale and (II) dark before they were incubated, resulting a factorial 3 x 2. Blood samples were collected at hatching and performance was measured from 1 to 35 days of age and in four phases: pre-starter (1-7 d) starter (8-21 d) and grower (22-35 d). Carcass yield was measured at 35 days. Supplementation with Fe had no effect on production, quality of eggs and eggshells colors (P>0.05). No interactions were found (P>0.05) but effects of supplementation and eggshell colors were observed. Supplementation 3 was superior to 1 (P<0.05), but both were similar to 2 in fertility and hatchability of eggs. No effects of eggshell colors was observed to such responses. Hemoglobin and hematocrit were not affected by any of the factors. The body weight gain was influenced by supplementation and eggshell, where the accumulated from 1 to 35 days the response of the supplementation 3 was higher than 2 and this higher than 1, similarly, the II was superior than I (P<0.05). The feed conversion was affected by eggshell color in the initial stages and growth, which, in both dark eggshells resulted in better indexes (P>0.05). The breast fillet was the only commercial cut affected by supplementation, where 3 was better than 2 and 1 (P>0.05) in relative values. The carcass yield and other commercial cuts were not affected by treatments. In conclusion, supplementation of diets for broiler breeders with Fe-AA, results in higher fertility and hatchability of eggs; Progeny, improves performance and breast meat yield. In addition, dark shell eggs provide chicks with superior growth performance.