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51.
The variations in lipid metabolism according to the physiological stage and their relationship to the resumption of postpartum ovarian cyclicity were assessed in Limousine beef cows fed a grass diet over 3 yr. Weekly blood samples were collected from 59 cows beginning 10 wk before to 20 wk after calving to evaluate serum cholesterol and triglyceride concentrations and electrophoretic lipoprotein fractions. After parturition, progesterone concentrations were also measured at weekly intervals to determine time of resumption of ovulation. Cows were categorized by resumption of postpartum ovarian cyclicity into 3 groups: early (4 to 6 wk post partum, n = 36); mid (7 to 10 wk post partum, n = 46) and late (after 11 wk post partum, n = 38). Higher serum triglyceride values (P<0.05) were observed during the last 10 wk of pregnancy (0.36+/-0.15 g/L) than during the first 20 wk of suckling (0.29+/-0.09 g/L). Cholesterol values decreased significantly (P<0.05) at the end of pregnancy, were minimal (1.01+/-0.03 g/L) at parturition, and increased again up to 9 wk post calving. Increased cholesterolemia and low serum triglyceride values after calving could be linked to the increased bovine alpha-lipoprotein fraction and decreased beta fraction. Serum triglyceride concentrations were not related to the resumption of postpartum ovarian cyclicity. Higher serum cholesterol values were observed from 2 wk before to 4 wk after calving in cows with early rather than mid and late resumption of ovarian cyclicity. Therefore, modifications in lipid metabolism during the puerperium seem to be related to resumption of cyclicity during the early postpartum period.  相似文献   
52.
Some misprints appeared on page 640, in Table II and in the last paragraph of Section 2.2 (line 9). One should read: "3.075 × 10-2", "-4.900 × 10-4", "1.440 × 10-5", "2.500 × 10-9" and "1.0 × 10-8", respectively (there are not exponential functions).  相似文献   
53.
This study projects future (e.g., 2050 and 2099) grassland productivities in the Greater Platte River Basin (GPRB) using ecosystem performance (EP, a surrogate for measuring ecosystem productivity) models and future climate projections. The EP models developed from a previous study were based on the satellite vegetation index, site geophysical and biophysical features, and weather and climate drivers. The future climate data used in this study were derived from the National Center for Atmospheric Research Community Climate System Model 3.0 ‘SRES A1B’ (a ‘middle’ emissions path). The main objective of this study is to assess the future sustainability of the potential biofuel feedstock areas identified in a previous study. Results show that the potential biofuel feedstock areas (the more mesic eastern part of the GPRB) will remain productive (i.e., aboveground grassland biomass productivity >2750 kg ha?1 year?1) with a slight increasing trend in the future. The spatially averaged EPs for these areas are 3519, 3432, 3557, 3605, 3752, and 3583 kg ha?1 year?1 for current site potential (2000–2008 average), 2020, 2030, 2040, 2050, and 2099, respectively. Therefore, the identified potential biofuel feedstock areas will likely continue to be sustainable for future biofuel development. On the other hand, grasslands identified as having no biofuel potential in the drier western part of the GPRB would be expected to stay unproductive in the future (spatially averaged EPs are 1822, 1691, 1896, 2306, 1994, and 2169 kg ha?1 year?1 for site potential, 2020, 2030, 2040, 2050, and 2099). These areas should continue to be unsuitable for biofuel feedstock development in the future. These future grassland productivity estimation maps can help land managers to understand and adapt to the expected changes in future EP in the GPRB and to assess the future sustainability and feasibility of potential biofuel feedstock areas.  相似文献   
54.
Macrophage Migration Inhibitory Factor (MIF) is a key mediator of inflammatory responses and innate immunity and has been implicated in the pathogenesis of several inflammatory and autoimmune diseases. The oligomerization of MIF, more specifically trimer formation, is essential for its keto-enol tautomerase activity and probably mediates several of its interactions and biological activities, including its binding to its receptor CD74 and activation of certain signaling pathways. Therefore, understanding the molecular factors governing the oligomerization of MIF and the role of quaternary structure in modulating its structural stability and multifunctional properties is crucial for understanding the function of MIF in health and disease. Herein, we describe highly conserved intersubunit interactions involving the hydrophobic packing of the side chain of Leu46 onto the β-strand β3 of one monomer within a hydrophobic pocket from the adjacent monomer constituted by residues Arg11, Val14, Phe18, Leu19, Val39, His40, Val41, Val42, and Pro43. To elucidate the structural significance of these intersubunit interactions and their relative contribution to MIF’s trimerization, structural stability and catalytic activity, we generated three point mutations where Leu46 was replaced by glycine (L46G), alanine (L46A) and phenylalanine (L46F), and their structural properties, stability, oligomerization state, and catalytic activity were characterized using a battery of biophysical methods and X-ray crystallography. Our findings provide new insights into the role of the Leu46 hydrophobic pocket in stabilizing the conformational state of MIF in solution. Disrupting the Leu46 hydrophobic interaction perturbs the secondary and tertiary structure of the protein but has no effect on its oligomerization state.  相似文献   
55.
Tumor Necrosis Factor receptor-associated factor-3 (TRAF3) is a central mediator important for inducing type I interferon (IFN) production in response to intracellular double-stranded RNA (dsRNA). Here, we report the identification of Sec16A and p115, two proteins of the ER-to-Golgi vesicular transport system, as novel components of the TRAF3 interactome network. Notably, in non-infected cells, TRAF3 was found associated with markers of the ER-Exit-Sites (ERES), ER-to-Golgi intermediate compartment (ERGIC) and the cis-Golgi apparatus. Upon dsRNA and dsDNA sensing however, the Golgi apparatus fragmented into cytoplasmic punctated structures containing TRAF3 allowing its colocalization and interaction with Mitochondrial AntiViral Signaling (MAVS), the essential mitochondria-bound RIG-I-like Helicase (RLH) adaptor. In contrast, retention of TRAF3 at the ER-to-Golgi vesicular transport system blunted the ability of TRAF3 to interact with MAVS upon viral infection and consequently decreased type I IFN response. Moreover, depletion of Sec16A and p115 led to a drastic disorganization of the Golgi paralleled by the relocalization of TRAF3, which under these conditions was unable to associate with MAVS. Consequently, upon dsRNA and dsDNA sensing, ablation of Sec16A and p115 was found to inhibit IRF3 activation and anti-viral gene expression. Reciprocally, mild overexpression of Sec16A or p115 in Hec1B cells increased the activation of IFNβ, ISG56 and NF-κB -dependent promoters following viral infection and ectopic expression of MAVS and Tank-binding kinase-1 (TBK1). In line with these results, TRAF3 was found enriched in immunocomplexes composed of p115, Sec16A and TBK1 upon infection. Hence, we propose a model where dsDNA and dsRNA sensing induces the formation of membrane-bound compartments originating from the Golgi, which mediate the dynamic association of TRAF3 with MAVS leading to an optimal induction of innate immune responses.  相似文献   
56.
We conducted three experiments for management of Bemisia tabaci (Gennadius) biotype ‘B’ on tomatoes under greenhouse conditions: (i) vertically placing yellow sticky cards either parallel or perpendicular to tomato rows at a rate of 1 per 3‐m row; (ii) releasing Eretmocerus sp. nr. rajasthanicus once at 30 adults/m2 in the high whitefly density greenhouses (> 10 adults/plant), or twice at 15 adults/m2 at a 5‐day interval in the low whitefly density greenhouses (< 10 adults/plant); and (iii) using combinations of yellow sticky cards that were placed vertically parallel to tomato rows and parasitoids released once at 30/m2 in high whitefly density greenhouses or twice at 15/m2 at a 5‐day interval in low whitefly density greenhouses. Our data show that yellow sticky cards trapped B. tabaci adults and significantly reduced whitefly populations on tomato. The yellow sticky cards that were placed parallel to tomato rows caught significantly more whitefly adults than those placed perpendicular to tomato rows on every sampling date. In the treatment where parasitoids were released once at 30/m2 in high whitefly density greenhouses, the number of live whitefly nymphs were reduced from 4.6/leaf to 2.9/leaf in 40 days as compared with those on untreated plants on which live whitefly nymphs increased from 4.4/leaf to 8.9/leaf. In the treatment where parasitoids were released twice at 15/m2 in low whitefly density greenhouses, the numbers of live nymphs of B. tabaci on tomato leaves were reduced from 2.1/leaf to 1.7/leaf in 20 days as compared with those on untreated plants on which numbers of live nymphs of B. tabaci increased from 2.2/leaf to 4.5/leaf. In the treatment of yellow sticky cards and parasitoid release once at 30/m2 in high whitefly density greenhouses, the numbers of live nymphs of B. tabaci on tomato leaves were reduced from 7.2/leaf to 1.9/leaf, and in the treatment of yellow sticky cards and parasitoid release twice at 15/m2 at a 5‐day interval at low whitefly density, the numbers of live nymphs of B. tabaci on tomato leaves were reduced from 2.5/leaf to 0.8/leaf; whereas the numbers of live nymphs of B. tabaci on untreated plants increased from 4.4/leaf to 8.9/leaf. An integrated program for management of B. tabaci on greenhouse vegetables by using yellow sticky cards, parasitoids and biorational insecticides is discussed.  相似文献   
57.

Background and Objective

Emerging evidence indicates that common functional polymorphisms in the estrogen receptor 1 (ESR1) gene may have an impact on an individual’s susceptibility to endometrial cancer, but individually published results are inconclusive. The aim of this meta-analysis is to derive a more precise estimation of the associations between eight polymorphisms in the ESR1 gene and endometrial cancer risk.

Methods

A literature search of PubMed, Embase, Web of Science and China Biology Medicine (CBM) databases was conducted on publications published before November 1st, 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistical analyses were performed using the STATA 12.0 software.

Results

Thirteen case-control studies were included with a total of 7,649 endometrial cancer cases and 16,855 healthy controls. When all the eligible studies were pooled into the meta-analysis, the results indicated that PvuII (C>T) polymorphism was associated with an increased risk of endometrial cancer, especially among Caucasian populations. There were also significant associations between rs3020314 (C>T) polymorphism and an increased risk of endometrial cancer. Furthermore, rs2234670 (S/L) polymorphism may decrease the risk of endometrial cancer. However, no statistically significant associations were found in XbaI (A>G), Codon 325 (C>G), Codon 243 (C>T), VNTR (S/L) and rs2046210 (G>A) polymorphisms.

Conclusion

The current meta-analysis suggests that PvuII (C>T) and rs3020314 (C>T) polymorphisms may be risk factors for endometrial cancer, especially among Caucasian populations.  相似文献   
58.
The dysregulation of miR-137 plays vital roles in the oncogenesis and progression of various types of cancer, but its role in prognosis of gastric cancer patients remains unknown. This study was designed to investigate the expression and prognostic significance of miR-137 in gastric cancer patients after radical gastrectomy. Quantitative real-time PCR (qRT-PCR) was performed to evaluate the expression of miR-137 in human gastric cancer cell lines and tissues in patients with gastric adenocarcinoma. Results were assessed for association with clinical factors and overall survival by using Kaplan-Meier analysis. Prognostic values of miR-137 expression and clinical outcomes were evaluated by Cox regression analysis. The results exhibited that the expression level of miR-137 was decreased in human gastric cancer cell lines and tissues, and down-regulated expression of miR-137 was associated with tumor cell differentiation, N stage, and TNM stage. Decreased miR-137 expression in gastric cancer tissues was positively correlated with poor overall survival of gastric cancer patients. Further multivariate Cox regression analysis suggested that miR-137 expression was an independent prognostic indicator for gastric cancer except for TNM stage. Applying the prognostic value of miR-137 expression to TNM stage III group showed a better risk stratification for overall survival. In conclusion, the results reinforced the critical role for the down-regulated miR-137 expression in gastric cancer and suggested that miR-137 expression could be a prognostic indicator for this disease. In addition, these patients with TNM stage III gastric cancer and low miR-137 expression might need more aggressive postoperative treatment and closer follow-up.  相似文献   
59.
The aim of this study is to investigate the capability of an apoA-I mimetic with multiple amphipathic helices to form HDL-like particles in vitro and in vivo. To generate multivalent helices and to track the peptide mimetic, we have constructed a peptibody by fusing two tandem repeats of 4F peptide to the C terminus of a murine IgG Fc fragment. The resultant peptidbody, mFc-2X4F, dose-dependently promoted cholesterol efflux in vitro, and the efflux potency was superior to monomeric 4F peptide. Like apoA-I, mFc-2X4F stabilized ABCA1 in J774A.1 and THP1 cells. The peptibody formed larger HDL particles when incubated with cultured cells compared with those by apoA-I. Interestingly, when administered to mice, mFc-2X4F increased both pre-β and α-1 HDL subfractions. The lipid-bound mFc-2X4F was mostly in the α-1 migrating subfraction. Most importantly, mFc-2X4F and apoA-I were found to coexist in the same HDL particles formed in vivo. These data suggest that the apoA-I mimetic peptibody is capable of mimicking apoA-I to generate HDL particles. The peptibody and apoA-I may work cooperatively to generate larger HDL particles in vivo, either at the cholesterol efflux stage and/or via fusion of HDL particles that were generated by the peptibody and apoA-I individually.  相似文献   
60.
不同生态环境对蒲公英超氧物歧化酶(SOD)的影响   总被引:5,自引:1,他引:5  
选择干生,湿生,阳生,阴生四种生境中生长的蒲公英Taraxacum mongolicum Hand.-Mazz分根,叶,花分别测定了SOD活性和比活性,并比较了同工酶谱的变化情况,结果表明不同生境未能改变SOD的同工酶条带数,但对其活性大小有影响,这种影响尤其表现在根上,湿生和阴生根的SOD活性明显高于干生和阳生根的SOD活性,显示出蒲公英的不同器官适应不同的环境效应。  相似文献   
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