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In this study, we investigated the fluctuations of concentration of intracytoplasmic free Ca(2+) during in vitro maturation of caprine primary oocytes and its role in meiotic resumption. Oocytes that were extracted from caprine ovaries were cultured and allowed to mature in vitro to determine their developmental stages including germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase of the first meiotic division (MI) and metaphase of the second meiotic division (MII). Intracytoplasmic free Ca(2+) turnovers of caprine oocytes at these different developmental stages were measured using the calcium fluorescent probe Fura-2/AM (C(44)H(47)N(3)O(24)) to investigate the dynamics of cytosolic free Ca(2+) during in vitro maturation of oocytes and the role of Ca(2+) in inducing the initiation of meiotic resumption of oocytes. Moreover, the oocytes were cultured in Ca(2+) culture medium and Ca(2+)-free culture medium to examine the effect of extracellular Ca(2+) on the oocyte maturation. The results indicated that Ca(2+) concentrations at GV, GVBD, MI and MII stages were 78.06, 147.41, 126.97 and 97.73 nmol/l, respectively, and that 86.30% of oocytes remained at the GV stage and no oocyte developed to MII in Ca(2+)-free culture medium, and 1.1% of oocytes stayed at the GV stage and 83.5% of oocytes developed to MII in Ca(2+) culture medium. These results suggest that the occurrence of GVBD and cell cycle progression to MI and MII stages are closely related to Ca(2+), and that extracellular Ca(2+) performs a specific function for the initiation of meiotic resumption in caprine oocytes.  相似文献   
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BACKGROUND: While adult populations have been well described in terms of nutritional status, such as the concentration of nutrient biomarkers, little work has been done in healthy paediatric populations. OBJECTIVE: The primary objective of this analysis was to explore the determinants of plasma micronutrients in a group of healthy infants and children. DESIGN: The Diabetes Autoimmunity Study in the Young (DAISY) has enrolled 1433 newborns at increased risk for type 1 diabetes in Denver, Colorado. A representative random sample of 257 children from the DAISY cohort between the ages of 9 months and 8 years with a total of 815 clinic visits over time was used in this analysis. Annual dietary intake was assessed over time with Willett food-frequency questionnaires that were validated in this population. Environmental tobacco smoke (ETS) was assessed using a validated survey. Plasma samples were tested for vitamins, carotenoids and total lipids. Predictors of plasma micronutrients were evaluated using mixed models for longitudinal data, while adjusting for age, human leukocyte antigen genotype, type 1 diabetes family history and other potential confounders and covariates. RESULTS: Increased micronutrient intake was associated with increased levels of their respective plasma nutrient, with the exception of gamma-tocopherol. Independent of dietary intake, levels of alpha- and beta-carotene and beta-cryptoxanthin were significantly lower, and gamma-tocopherol was significantly higher, in children who were exposed to ETS. CONCLUSION: Dietary intake predicts plasma micronutrient levels. Exposure to ETS potentially could have negative health effects in this young population.  相似文献   
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Soluble peptide factors have been implicated as the agents responsible for embryonic inductions in vertebrates. Here, a protein (PIF) secreted by a mouse macrophage cell line is shown to change the developmental fate of Xenopus embryonic cells. Exposure to PIF causes presumptive ectodermal explants to form anterior neural and mesodermal tissues, including brain and eye, instead of ciliated epidermis. In addition, the induced tissues are organized into a rudimentary embryonic axis. These results suggest that PIF or a closely related molecule is involved in inducing anterior structures and organizing the frog body plan.  相似文献   
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At the time of the Soufriere, St. Vincent, volcanic eruption of 17 April 1979, a NASA P-3 aircraft with an uplooking lidar (light detection and ranging) system onboard was airborne 130 kilometers east of the island. Lidar measurements of the fresh volcanic ash were made approximately 2 hours after the eruption, 120 kilometers to the northeast and east. On the evening of 18 April, the airborne lidar, on a southerly flight track, detected significant amounts of stratospheric material in layers at 16, 17, 18, and 19.5 kilometers. These data, and measurements to the north on 19 April, indicate that the volcanic plume penetrated the stratosphere to an altitude of about 20 kilometers and moved south during the first 48 hours after the eruption.  相似文献   
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In this study, we aim to investigate the skull of Bardhoka sheep, which is the native breed of Kosovo by utilising normal morphometric methods. Differences between male and female were also statistically analysed. Further, the parameters that can be used in gender discrimination were also analysed. The statistical analysis was based on a sample of 24 adult skulls of Bardhoka breed with 12 female and 12 male skulls. Altogether, 31 different measurements were taken morphologically and 7 different indices were applied. Except for the measurement's values of the orbit, measurement's values of length of the cheek tooth row and the measurement's values of height of the foramen magnum, all the measured values of males were higher than females. Nasal index, cranium index and skull index values were statistically significant between both genders. It is envisaged that the findings of this study will motivate and assist other comparative studies with other autochthonous sheep and goat breeds found in the Dukagjini region or in clinical veterinary practice and even in zooarchaeology.  相似文献   
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Fifty dairy cows with metabolic alkalosis and forty-eight dairy cows of a control group were subjected to a metabolic profile test with 30 parameters. The results of analyses were confronted with reference values in histograms. We calculated mutual correlation coefficients for all parameters of dairy cows of the two groups. The correlations between selected pairs of parameters were represented diagrammatically in a form of correlograms. We demonstrated that the values of certain parameters being approximately identical, the correlations in group A of dairy cows (with alkalosis) varied in a different way from the correlations of the control group. It is seen from the results that the confrontation of the values of a parameter with reference values need not be in all cases a reliable criterion of evaluating the internal environment in dairy cows. We processed the metabolic profiles of the two groups by a multidimensional analysis of principal components. The dairy cows of the two groups clearly differentiated from one another according to the internal environment regarding the used parameters. We draw attention to a possibility of computerizing the diagnostic significance of the metabolic profile parameters.  相似文献   
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