Effects of Perfluorooctane sulfonate (PFOS) on Physiological Status and Proliferation Capacity of Chlorella pyrenoidosa

Author(s):  
De-Yong Zhang ◽  
Xiao-Lu Xu ◽  
Xiu-Ying Shen
2012 ◽  
Vol 209-211 ◽  
pp. 1131-1135 ◽  
Author(s):  
De Yong Zhang ◽  
Xiao Lu Xu ◽  
Yin Lu ◽  
Hui Ying Xu ◽  
Hui Min Yan

To evaluate the toxic effects of environmental contaminant PFOS on green algae, Scenedesmus obliqnus was cultured in media containing serially diluted PFOS for evaluation of proliferation capacity and some physiological indexes. Within 96h, PFOS doses ≥50 mg/L all inhibited the proliferation speed of Scenedesmus obliqnus(p<0.05). The 96h EC50 value of PFOS was determined to be 126 mg/L. In a chronic experiment with 8 days of PFOS treatment, chlorophyll a content, which was inhibited by even the lowest dose, showed to be the most sensitive index to PFOS contamination. PFOS doses ≥100mg/L all resulted in decreasing of antioxidant enzyme activity and increasing of MDA content in Scenedesmus obliqnus(P<0.05).


2012 ◽  
Vol 82 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Violeta Fajardo ◽  
Gregorio Varela-Moreiras

In the past, food fortification along with nutritional education and the decrease in food costs relative to income have proven successful in eliminating common nutritional deficiencies. These deficiencies such as goiter, rickets, beriberi, and pellagra have been replaced with an entirely new set of “emergent deficiencies” that were not previously considered a problem [e.g., folate and neural tube defects (NTDs)]. In addition, the different nutrition surveys in so-called affluent countries have identified “shortfalls” of nutrients specific to various age groups and/or physiological status. Complex, multiple-etiology diseases, such as atherosclerosis, diabetes, cancer, and obesity have emerged. Food fortification has proven an effective tool for tackling nutritional deficiencies in populations; but today a more reasonable approach is to use food fortification as a means to support but not replace dietary improvement strategies (i. e. nutritional education campaigns). Folic acid (FA) is a potential relevant factor in the prevention of a number of pathologies. The evidence linking FA to NTD prevention led to the introduction of public health strategies to increase folate intakes: pharmacological supplementation, mandatory or voluntary fortification of staple foods with FA, and the advice to increase the intake of folate-rich foods. It is quite contradictory to observe that, regardless of these findings, there is only limited information on food folate and FA content. Data in Food Composition Tables and Databases are scarce or incomplete. Fortification of staple foods with FA has added difficulty to this task. Globally, the decision to fortify products is left up to individual food manufacturers. Voluntary fortification is a common practice in many countries. Therefore, the “worldwide map of vitamin fortification” may be analyzed. It is important to examine if fortification today really answers to vitamin requirements at different ages and/or physiological states. The real impact of vitamin fortification on some key biomarkers is also discussed. An important question also to be addressed: how much is too much? It is becoming more evident that chronic excessive intakes may be harmful and a wide margin of safety seems to be a mandatory practice in dietary recommendations. Finally, the “risk/benefit” dilemma is also considered in the “new” FA-fortified world.


Reproduction ◽  
2000 ◽  
pp. 311-323 ◽  
Author(s):  
JL Hilton ◽  
GE Sarty ◽  
GP Adams ◽  
RA Pierson

The magnetic resonance images and maps of bovine ovaries acquired at defined phases of follicular development and regression were studied to determine whether magnetic resonance image attributes of the follicular antrum reflect the physiological status of dominant and subordinate ovarian follicles. Ovariectomies were performed at day 3 of wave one, day 6 of wave one, day 1 of wave two and at >/= day 17 after ovulation. The timings of ovariectomies were selected to acquire growing, early static, late static and regressing follicles of the first wave and preovulatory follicles of the ovulatory wave. Pre-selection and subordinate follicles were also available for analysis. Serum samples were taken on the day of ovariectomy and follicular fluid samples were taken after imaging. Numerical pixel value and pixel heterogeneity in a spot representing approximately 95% of the follicular antrum were quantified in T(1)- and T(2)-weighted images. T(1) and T(2) relaxation rates (T(1) and T(2)), proton density, apparent diffusion coefficients and their heterogeneities were determined from the computed magnetic resonance maps. The antra of early atretic dominant follicles showed higher T(2)-weighted mean pixel value (P < 0.008) and heterogeneity (P < 0. 01) and lower T(2) heterogeneity (P < 0.008) than growing follicles. Subordinate follicles in the presence of a preovulatory dominant follicle had higher T(1), T(1) heterogeneity, proton density, proton density heterogeneity, and lower mean pixel value in T(1)-weighted images than subordinate follicles of the anovulatory wave (P < 0.04). T(1) relaxation rate heterogeneity and proton density heterogeneity were positively correlated with follicular fluid oestradiol concentration (r = 0.4 and 0.3; P < 0.04). T(2) relaxation rate heterogeneity was positively correlated with follicular fluid progesterone concentration (r = 0.4; P < 0.008). Quantitative differences in magnetic resonance image attributes of the antrum observed among phases of follicular development and regression coincided with changes in the ability of the dominant follicle to produce steroid hormones and ovulate, and thus were indicative of physiological status and follicular health.


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