139 research outputs found

    The chicken embryo and its micro environment during egg storage and early incubation

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    When egg storage periods are prolonged (>7 days), hatchability and chick quality declines. The reason for this decline has been investigated, but is still not completely understood. At oviposition the developmental stage of the chicken embryo varies and so do the total number of viable cells. During storage, changes can occur in the embryo. Embryo viability at the end of storage seems to be dependent on the number of viable cells and the developmental stage of the embryo at oviposition. When the hypoblast is completely formed (during the quiescent developmental stage), the embryo seems to be more able to endure prolonged storage periods than embryos that are less or more advanced. During storage, changes also occur in egg characteristics such as albumen viscosity, albumen pH and yolk pH. There appears to be an interaction between albumen pH and embryo viability during early incubation and perhaps also during storage. An albumen pH of 8.2 seems to be optimal for embryo development. Albumen pH may influence embryo viability, but embryo viability may in turn, affect albumen pH. It has been hypothesised that an embryo in which the hypoblast is completely formed is better able to provide an effective barrier between the internal embryo and the exterior (yolk and albumen) and/or is better able to produce sufficient amount of carbon dioxide, which will reduce the pH level in the micro environment of the embryo to the optimal pH of 8.2. It appears that, to maintain hatchability and chick quality after prolonged storage periods, embryonic development should be advanced to the stage in which the hypoblast is completely formed or the atmosphere during storage and early incubation should be altered in such a way that albumen pH is maintained at the optimal level of 8.2

    Cardiovascular disease in type 2 diabetes mellitus and chronic kidney disease:imaging modalities and pathogenetic mechanisms

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    Patients with cardiovascular diseases and risk factors are regarded a high risk group as a whole. However, the underlying mechanisms between patients might differ significantly. By investigating these processes on a cellular and systemic level, treatment options can be optimized and personalized. In this thesis we demonstrated that patients with type 2 diabetes mellitus and chronic kidney disease are at an increased risk for developing cardiovascular diseases, due to the process of accelerated vascular ageing in terms of arterial inflammation and calcification. In patients with type 2 diabetes mellitus, an increased amount of visceral adipose tissue is related to a rise in arterial inflammation. Additional presence of albuminuria in these patients is an indication for subclinical arterial disease with increased arterial micro-calcification and arterial stiffness. In patients with chronic kidney disease, adipose tissue is characterized by an increased inflammatory state, which promotes vascular disease. We found that metabolic changes, systemic and local inflammation and other biological factors, such as angiogenic factors, result in vascular changes, affecting the development of cardiovascular diseases. Imaging techniques and vascular measurements provide insights into the underlying processes, and are useful for detection and evaluation of de progression of vascular disease. Also lab measurements investigating insulin resistance, cholesterol, kidney function, and albuminuria are important features for risk stratification. By demonstrating that these markers are related to vascular changes, this thesis contributes to personalized medicine and, therefore, in prevention for the development and progression of cardiovascular diseases

    Relationship between hatchling length and weight on later productive performance in broilers

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    Hatchling length and weight are used as tools to measure hatchling quality. However, the relationship between these parameters and later performance are not well known. This review evaluates the relationship between hatchling length or weight and slaughter weight, breast meat yield and feed conversion ratio (FCR) in both male and female broilers. Datasets from two trials were compared. In the first, hatchling length and weight of 100 male and 100 female broilers were measured and body weight and breast meat yield were determined at 38 days of age. In experiment 2, hatchling length of 187 female and 230 male broilers was measured and body weight was determined at 21 and 42 days of age. Feed intake was determined between 21 and 42 days of age. In both experiments, male broilers showed a positive relationship between hatchling length and slaughter weight or breast meat yield, but no relationship was found with hatchling weight. The relationship between hatchling length and performance in female broilers differed between the two experiments. In female broilers, a negative relationship between hatchling weight and breast meat yield was found. No relationship between hatchling length and FCR in both male and female broilers was found. From this limited dataset, it can be concluded that hatchling length seems to be a better parameter to predict subsequent chick performance, excluding FCR, than hatchling weight, but gender needs to be taken into accoun

    Meeting embryonic requirements of broilers throughout incubation: a review

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    During incubation of chicken embryos, environmental conditions, such as temperature, relative humidity, and CO2 concentration, must be controlled to meet embryonic requirements that change during the different phases of embryonic development. In the current review, the effects of embryo temperature, egg weight loss, and CO2 concentration on hatchability, hatchling quality, and subsequent performance are discussed from an embryonic point of view. In addition, new insights related to the incubation process are described. Several studies have shown that a constant eggshell temperature (EST) of 37.5 to 38.0 degrees C throughout incubation results in the highest hatchability, hatchling quality, and subsequent performance. Egg weight loss must be between 6.5 and 14.0% of the initial egg weight, to obtain an adequate air cell size before the embryo internally pips. An increased CO2 concentration during the developmental phase of incubation (first 10 days) can accelerate embryonic development and hatchability, but the physiological mechanisms of this acceleration are not completely understood. Effects of ar increased CO2 concentration during late incubation also need further investigation. The preincubation warming profile, thermal manipulation, and in ovo feeding are new insights related to the incubation process and show that the optimal situation for the embryo during incubation highly depends on the conditions of the eggs before (storage duration) and during incubation (environmental conditions) and on the conditions of the chickens after hatching (environmental temperature)

    Storage of Hatching Eggs : Effects of storage and early incubation conditions on egg characteristics, embryonic development, hatchability, and chicken quality

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    Key words: egg storage, embryonic development, albumen quality, hatchability, chick quality It is well known that an increase in the storage duration increases incubation duration and decreases hatchability and chick quality. The negative effects of prolonged egg storage (> 7 days) may be caused by changes in the embryo, in the egg characteristics, or by both. The first aim of the current thesis was to investigate which physiological mechanisms are involved in the negative effects of prolonged egg storage on hatchability and chick quality. The second aim was to investigate how these negative effects of prolonged egg storage can be reduced by making changes in storage or early incubation conditions. Treatments, such as prestorage incubation, frequent warming during storage, a change in the storage air composition, different preincubation warming profiles, and hypercapnic incubation during the first 5 days of incubation were used in the current thesis to gain more insight in the cause of the negative effects of prolonged egg storage. Prestorage incubation and frequent warming during storage increased the stage of embryonic development and the number of viable embryonic cells. The effect of these treatments on hatchability was nihil, positive or negative and seems to depend on the stage of embryonic development before and after the treatment. The storage air compositions, studied in the current thesis did not affect embryonic development, hatchability, or chick quality, when eggs were stored for 14 days. This suggests that changes in albumen quality during storage do not affect hatchability and chick quality. The 24-h preincubation warming profile decreased embryonic mortality during the first 9 days of incubation in comparison with the 4-h preincubation warming profile when eggs were stored for 13 days. Hypercapnic incubation during the first 5 days of incubation decreased albumen pH during early incubation, but did not improve hatchability. In conclusion, embryo characteristics seem to have a more important role in the negative effects of prolonged egg storage than changes in the egg characteristics, such as changes in the albumen pH and albumen height. <br/

    A crise da democracia consensual tematizada a partir da perspectiva da filosofia política de Rancière

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    O presente texto tem como escopo desvendar, a partir da visão política de Rancière, o aparente paradoxo existente nas recentes manifestações sociais, em especial os protestos que tomaram corpo em junho de 2013 no Brasil. Tais movimentos geraram duas avaliações supostamente contraditórias: uma de crise democrática; outra de fortalecimento da democracia política. Com o intuito de mostrar que ambas as avaliações são válidas e nem por isso contraditórias, o artigo em questão toma por base as lições de Jacques Rancière e busca, em um primeiro momento, estabelecer os principais elementos que caracterizam a atividade política segundo o filósofo, bem como seu contraponto, o que o autor denomina de “polícia”. Após, conceitua-se a proposta democrática desenvolvida por Rancière baseada no dissenso, o que vem a ser uma clara oposição a atual democracia enquanto forma de governo consensual. Por fim, partindo da ideia de existência de duas visões de democracia, elucidase o aparente paradoxo instaurado, assim como o atual cenário de rebeldia que se mostra nas ruas

    [18F]-sodium fluoride autoradiography imaging of nephrocalcinosis in donor kidneys and explanted kidney allografts

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    Nephrocalcinosis is present in up to 43% of kidney allograft biopsies at one-year after transplantation and is associated with inferior graft function and poor graft survival. We studied [18F]-sodium fluoride ([18F]-NaF) imaging of microcalcifications in donor kidneys (n = 7) and explanted kidney allografts (n = 13). Three µm paraffin-embedded serial sections were used for histological evaluation of calcification (Alizarin Red; Von Kossa staining) and ex-vivo [18F]-NaF autoradiography. The images were fused to evaluate if microcalcification areas corresponded with [18F]-NaF uptake areas. Based on histological analyses, tubulointerstitial and glomerular microcalcifications were present in 19/20 and 7/20 samples, respectively. Using autoradiography, [18F]-NaF uptake was found in 19/20 samples, with significantly more tracer activity in kidney allograft compared to deceased donor kidney samples (p = 0.019). Alizarin Red staining of active microcalcifications demonstrated good correlation (Spearman's rho of 0.81, p < 0.001) and Von Kossa staining of consolidated calcifications demonstrated significant but weak correlation (0.62, p = 0.003) with [18F]-NaF activity. This correlation between ex-vivo [18F]-NaF uptake and histology-proven microcalcifications, is the first step towards an imaging method to identify microcalcifications in active nephrocalcinosis. This may lead to better understanding of the etiology of microcalcifications and its impact on kidney transplant function

    Toward Reliable Uptake Metrics in Large Vessel Vasculitis Studies

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    The aim of this study is to investigate the influence of sex, age, fat mass, fasting blood glucose level (FBGL), and estimated glomerular filtration rate (eGFR) on blood pool activity in patients with large vessel vasculitis (LVV). Blood pool activity was measured in the superior caval vein using mean, maximum, and peak standardized uptake values corrected for body weight (SUVs) and lean body mass (SULs) in 41 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans of LVV patients. Sex influence on the blood pool activity was assessed with t-tests, while linear correlation analyses were used for age, fat mass, FBGL, and eGFR. Significantly higher SUVs were found in women compared with men, whereas SULs were similar between sexes. In addition, higher fat mass was associated with increased SUVs (r = 0.56 to 0.65; all p p > 0.05). Lower eGFR was associated with a higher FDG blood pool activity for all uptake values. In FDG-PET/CT studies with LVV patients, we recommend using SUL over SUV, while caution is advised in interpreting SUV and SUL measures when patients have impaired kidney function

    [18F]FDG and [18F]NaF as PET markers of systemic atherosclerosis progression:A longitudinal descriptive imaging study in patients with type 2 diabetes mellitus

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    BACKGROUND: While [18F]-fluordeoxyglucose ([18F]FDG) uptake is associated with arterial inflammation, [18F]-sodium fluoride ([18F]NaF) is a marker for arterial micro-calcification. We aimed to investigate the prospective correlation between both PET markers over time and whether they are prospectively ([18F]FDG) and retrospectively ([18F]NaF) related to progression of systemic arterial disease in a longitudinal study in patients with type 2 diabetes mellitus (T2DM). METHODS: Baseline [18F]FDG PET/Low Dose (LD) Computed Tomography (CT) scans of ten patients with early T2DM without cardiovascular history (70% men, median age 63 years) were compared with five-year follow-up [18F]NaF/LDCT scans. Systemic activity was expressed as mean target-to-background ratio (meanTBR) by dividing the maximal standardized uptake value (SUVmax) of ten arteries by SUVmean of the caval vein. CT-assessed macro-calcifications were scored visually and expressed as calcified plaque (CP) score. Arterial stiffness was assessed with carotid-femoral pulse wave velocity (PWV). Five-year changes were expressed absolutely with delta (Δ) and relatively with %change. RESULTS: Baseline meanTBR[18F]FDG was strongly correlated with five-year follow-up meanTBR[18F]NaF (r = 0.709, P = .022). meanTBR[18F]NaF correlated positively with ΔCPscore, CPscore at baseline, and follow-up (r = 0.845, P = .002 and r = 0.855, P = .002, respectively), but not with %change in CPscore and PWV. CONCLUSION: This proof-of-concept study demonstrated that systemic arterial inflammation is an important pathogenetic factor in systemic arterial micro-calcification development

    Severely increased albuminuria in patients with type 2 diabetes mellitus is associated with increased subclinical atherosclerosis in femoral arteries with Na [<sup>18</sup>F]F activity as a proxy:The DETERMINE study

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    Background and aims: Sodium [18F]fluoride (Na [18F]F) positron emission tomography imaging allows detailed visualization of early arterial micro-calcifications. This study aims to investigate atherosclerosis manifested by micro-calcification, macro-calcification, and aortic stiffness in patients with type 2 diabetes mellitus (T2DM) with and without albuminuria and severely decreased kidney function.Methods: A cohort was stratified in four groups (N = 10 per group), based on KDIGO categories (G1-5 A1-3). G1-2A1 non-diabetic controls (median [IQR] estimated glomerular filtration rate (eGFR) in mL/min/1.73 m2 91 [81–104]), G1-2A1 with T2DM (eGFR 87 [84–93], and albumin-creatinin-ratio (ACR) in mg/mmol 0.35 [0.25–0.75]), G1-2A3 with T2DM (eGFR 85 [60–103], and ACR 74 [62–122], and G4A3 with T2DM (eGFR 19 [13-27] and ACR 131 [59–304]). Results: Na [18F]F femoral artery grading score differed significantly in the groups with the highest Na [18F]F activity in A3 groups with T2DM (G1-2A3 with T2DM 228 [100–446] and G4A3 with T2DM 198 [113–578]) from the lowest groups of the G1-2A1 with T2DM (33 [0–93]) and in G1-2A1 non-diabetic controls (75 [0–200], p = 0.001). Aortic Na [18F]F activity and femoral artery computed tomography (CT)-assessed macro-calcification was increased in G4A3 with T2DM compared with G1-2A1 with T2DM (47.5 [33.8–73.8] vs. 17.5 [8.8–27.5] (p = 0.006) and 291 [170–511] vs. 12.2 [1.41–44.3] mg (p = 0.032), respectively). Carotid-femoral pulse wave velocity (PWV)-assessed aortic stiffness was significantly higher in both A3 groups with T2DM compared with G1-2A1 with T2DM (11.15 and 12.35 vs. 8.86 m/s, respectively (p = 0.009)). Conclusions: This study indicates that the presence of severely increased albuminuria in patients with T2DM is cross-sectionally associated with subclinical arterial disease in terms of micro-calcification and aortic stiffness. Additional decrease in kidney function was associated with advanced macro-calcifications.</p
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