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71.
72.
To evaluate the effect of dietary and management factors on boar hormonal status during ejaculation, 39 boars were canulated to determine the profiles of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17β-estradiol (E2), and testosterone (T) in blood plasma and seminal fluid. Prior to canulation, 18 boars were fed a basal diet (control), whereas the remainder (n = 21) were fed a basal diet supplemented with extra vitamins (supplemented). Within each dietary treatment, two regimens of semen collection were used over the 3 mo preceding the hormonal evaluation: three times per 2 wk (3/2) or three times per wk (3/1). Plasma E2 was lower (P < 0.01) before ejaculation (232.5 ± 22.6 pg/mL) than at the onset of ejaculation (255.2 ± 27.1 ng/mL). Plasma T increased from 5.14 ± 0.72, before ejaculation to 5.87 ± 0.86 ng/mL at the onset of ejaculation in supplemented boars, whereas it decreased from 5.15 ± 0.65 to 4.87 ± 0.70 ng/mL in controls (diet by time, P < 0.05). At the onset of ejaculation, plasma FSH was higher in 3/2 boars (0.436 ± 0.06 ng/mL) than in 3/1 boars (0.266 ± 0.04 ng/mL; P < 0.05). During ejaculation, plasma LH increased linearly (P < 0.01) from 0.59 ± 0.07 to 0.97 ± 0.10 ng/mL, and plasma E2 and T concentrations were correlated (r = 0.62, P < 0.01). Plasma FSH before and during ejaculation was negatively correlated with sperm production (r = −0.60, P < 0.01) and testicular weight (r = −0.50, P < 0.01). In conclusion, dietary and management factors had few impacts on hormonal profiles during ejaculation, but homeostasis of some hormones was related to some criteria of reproductive performance in boars. 相似文献
73.
Status of complete proteome analysis by mass spectrometry: SILAC labeled yeast as a model system 总被引:5,自引:1,他引:4
Background
Mass spectrometry has become a powerful tool for the analysis of large numbers of proteins in complex samples, enabling much of proteomics. Due to various analytical challenges, so far no proteome has been sequenced completely. O'Shea, Weissman and co-workers have recently determined the copy number of yeast proteins, making this proteome an excellent model system to study factors affecting coverage. 相似文献74.
Background
Optical imaging is an attractive non-invasive way to evaluate the expression of a transferred DNA, mainly thanks to its lower cost and ease of realization. In this study optical imaging was evaluated for monitoring and quantification of the mouse knee joint and tibial cranial muscle electrotransfer of a luciferase encoding plasmid. Optical imaging was applied to study the kinetics of luciferase expression in both tissues. 相似文献75.
Juliana R Martins Francis MF Nunes Alexandre S Cristino Zilá LP Simões Márcia MG Bitondi 《BMC molecular biology》2010,11(1):23
Background
Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. 相似文献76.
Margarida Cepa Georgina Correia-da-Silva Elisiário J Tavares da Silva Fernanda MF Roleira Margarida Borges Natércia A Teixeira 《BMC cell biology》2008,9(1):41
Background
Aromatase, the cytochrome P-450 enzyme (CYP19) responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI), which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds 3a and 4a, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells. 相似文献77.
78.
Cytokine-induced upregulation of NF-kappaB, IL-8, and ICAM-1 is dependent on colonic cell polarity: implication for PKCdelta 总被引:3,自引:0,他引:3
Vallee S Laforest S Fouchier F Montero MP Penel C Champion S 《Experimental cell research》2004,297(1):165-185
As described for a long time, carcinoma-derived Caco-2 cells form a polarized epithelium in culture, whereas HT29-D4 cells are nonpolarized and undifferentiated but can form a polarized monolayer when cultured in a galactose-supplemented medium. Using NF-kappaB translocation and IL-8 and ICAM-1 gene activation as an index, we have studied the relationship between the differentiation state and the cell response to cytokines. We found that differentiated Caco-2 and HT29-D4 cells were responsive to both cytokines TNFalpha- and IL-1beta-mediated activation of NF-kappaB but that undifferentiated HT29-D4 cells were unresponsive to IL-1beta. However, the expression of endogenous ICAM-1 and IL-8 genes was upregulated by these cytokines in either cell lines differentiated or not. Upregulation of ICAM-1 gene occurred when IL-1beta or TNFalpha was added to the basal, but not apical surface of the differentiated epithelia. Finally, it appeared that in polarized HT29-D4 cells, the IL-1beta-induced translocation of NF-kappaB was connected to PKCdelta translocation. 相似文献
79.
The objective was to determine the effects of folic acid+glycine supplement on uterine metabolism of prostaglandin and mRNA expression of endometrial granulocyte-macrophage colony-stimulating factor (GM-CSF) in nulliparous (NYL) and multiparous Yorkshire-Landrace (YL) sows, and in multiparous Meishan-Landrace sows (ML). In each of these three groups, sows were randomly assigned to two treatments: 15 ppm folic acid+0.6% glycine or no supplement. The dietary supplement was given from the estrus before mating to slaughter on Day 25 of pregnancy. At slaughter, endometrial tissue was collected to determine endometrial expression levels of GM-CSF mRNA, cyclooxygenase-1 (COX1) and -2 (COX2) and to evaluate in vitro endometrial secretion of prostaglandin E2 (PGE2) secretion. Allantoic fluid samples were also collected to determine the concentration of PGE2, prostaglandin F2alpha (PGF2alpha), estradiol-17beta (E2), progesterone (P4), and transforming-growth factor-beta2 (TGF-beta2). The allantoic contents of PGF2alpha, E2 and P4, and endometrial in vitro secretion of PGE2 were not significantly influenced by the folic acid+glycine supplement. The folic acid+glycine supplement tended (P<0.07) to increase allantoic content of PGE2 and TGF-beta2 in all sows and increased (P<0.05) endometrial expression of COX2, especially in NYL sows. The endometrial expression of COX1 was decreased (P<0.05) by folic acid+glycine supplement, especially in multiparous YL sows. The allantoic contents of PGE2 and PGF2alpha were not significantly affected by sow type. However, NYL sows had higher (P<0.05) endometrial in vitro secretion of PGE2 and allantoic content of P4 than multiparous YL and ML sows. The allantoic content of E2 was also higher (P<0.05) in NYL sows than in multiparous ML sows only. The allantoic content of TGF-beta2 was lower (P<0.05) in multiparous ML than in multiparous YL only sows. Finally, in YL and NYL sows, folic acid+glycine supplement decreased (P<0.05) the endometrial expression of GM-CSF but not in ML sows. In summary, folic acid+glycine supplement altered endometrial expression of GM-CSF and uterine metabolism of prostaglandins during the post-attachment period of porcine embryos but some of these effects were manifest only in Meishan and nulliparous sows. 相似文献
80.
5' tRNA editing has been demonstrated to occur in the mitochondria of the distantly related rhizopod amoeba Acanthamoeba castellanii and the chytridiomycete fungus Spizellomyces punctatus. In these organisms, canonical tRNA structures are restored by removing mismatched nucleotides at the first three 5' positions and replacing them with nucleotides capable of forming Watson-Crick base pairs with their 3' counterparts. This form of editing seems likely to occur in members of Amoebozoa other than A. castellanii, as well as in members of Heterolobosea. Evidence for 5' tRNA editing has not been found to date, however, in any other fungus including the deeply branching chytridiomycete Allomyces macrogynus. We predicted that a similar form of tRNA editing would occur in members of the chytridiomycete order Monoblepharidales based on the analysis of complete mitochondrial tRNA complements. This prediction was confirmed by analysis of tRNA sequences using a tRNA circularization/RT-PCR-based approach. The presence of partially and completely unedited tRNAs in members of the Monoblepharidales suggests the involvement of a 5'-to-3' exonuclease rather than an endonuclease in removing the three 5' nucleotides from a tRNA substrate. Surprisingly, analysis of the mtDNA of the chytridiomycete Rhizophydium brooksianum, which branches as a sister group to S. punctatus in molecular phylogenies, did not suggest the presence of editing. This prediction was also confirmed experimentally. The absence of tRNA editing in R. brooksianum raises the possibility that 5' tRNA editing may have evolved twice independently within Chytridiomycota, once in the lineage leading to S. punctatus and once in the lineage leading to the Monoblepharidales. 相似文献