排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
Effect of Oil Overlay on Inhibition Potential of Roscovitine in Sheep Cumulus‐Oocyte Complexes
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
LF Crocomo WC Marques Filho CMV Ulian NS Branchini DT Silva CL Ackermann FC Landim‐Alvarenga SD Bicudo 《Reproduction in domestic animals》2015,50(3):410-416
Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO2. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression. 相似文献
2.
Asagiri M Hirai T Kunigami T Kamano S Gober HJ Okamoto K Nishikawa K Latz E Golenbock DT Aoki K Ohya K Imai Y Morishita Y Miyazono K Kato S Saftig P Takayanagi H 《Science (New York, N.Y.)》2008,319(5863):624-627
Cathepsin K was originally identified as an osteoclast-specific lysosomal protease, the inhibitor of which has been considered might have therapeutic potential. We show that inhibition of cathepsin K could potently suppress autoimmune inflammation of the joints as well as osteoclastic bone resorption in autoimmune arthritis. Furthermore, cathepsin K-/- mice were resistant to experimental autoimmune encephalomyelitis. Pharmacological inhibition or targeted disruption of cathepsin K resulted in defective Toll-like receptor 9 signaling in dendritic cells in response to unmethylated CpG DNA, which in turn led to attenuated induction of T helper 17 cells, without affecting the antigen-presenting ability of dendritic cells. These results suggest that cathepsin K plays an important role in the immune system and may serve as a valid therapeutic target in autoimmune diseases. 相似文献
3.
DT Rodbell GO Seltzer DM Anderson MB Abbott DB Enfield JH Newman 《Science (New York, N.Y.)》1999,283(5401):516-520
Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds. 相似文献
4.
The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor 总被引:1,自引:0,他引:1
GM Keating SW Bougher RW Zurek RH Tolson GJ Cancro SN Noll JS Parker TJ Schellenberg RW Shane BL Wilkerson JR Murphy JL Hollingsworth RM Haberle M Joshi JC Pearl BJ Conrath MD Smith RT Clancy RC Blanchard RG Wilmoth DF Rault TZ Martin DT Lyons PB Esposito MD Johnston al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676
The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere. 相似文献
5.
Patterns of Follicular Growth in Superovulated Sheep and Influence on Endocrine and Ovarian Response
A Gonzalez-Bulnes RM Garcia-Garcia CJH Souza J Santiago-Moreno A Lopez-Sebastian MJ Cocero DT Baird 《Reproduction in domestic animals》2002,37(6):357-361
Objectives of this study were to characterize patterns of follicular development in sheep superovulated with purified follicle stimulating hormone (FSH) (OVAGENTM, ICP, Auckland, New Zealand) and to determine its influence on preovulatory events (onset of the oestrus behaviour and timing of the preovulatory luteinizing hormone surge) and ovarian response (ovulation rate and embryo yield). Number and size of all ≥ 23 mm follicles from the first FSH injection to withdrawal of progestagen sponges was determined by transrectal ultrasonography just prior to every FSH injection in nine Manchega ewes superovulated with eight decreasing doses (ml) (1.5 × 3, 1.25 × 2 and 1 × 3) of OVAGEN injected twice daily from 60 h before to 24 h after the withdrawal of 40 mg fluorogestone acetate sponges. Oestrous detection and jugular blood sampling for LH radioimmunoassay were performed every 3 h from 14 to 53 h after sponge removal and ovulation rate and number of embryos were determined 4 days after progestagen withdrawal. Administration of OVAGEN induced a significant rise (p < 0.0005) in the number of follicles ≥ 4 mm in size because of an increased growth in size of follicles from the first FSH injection to sponge removal, an increase in the number of newly detected follicles from 12 to 36 h of the first FSH dose (p < 0.005) and a decrease in regression rate from 24 h (p < 0.001). The number of follicles 2–3 mm in size at first FSH dose (10.4 ± 1.5) was positively correlated with the number of ≥ 4 mm follicles at 0 h (19.0 ± 2.7, p < 0.01). A higher number of ≥ 4 mm follicles at 0 h was related with an earlier appearance of oestrus (31.5 ± 1.5 h, p = 0.08) and LH surge (45.0 ± 2.3 h, p < 0.005), and a higher ovulation rate (18.2 ± 3.8, p < 0.005). On the other hand, the rate of embryo recovery was decreased in ewes with earlier preovulatory LH peaks (p < 0.005), with a shorter interval between oestrus and LH peak (p < 0.05). 相似文献
6.
Many scientists have expended efforts to determine what regulates development of an indifferent gonad into either a testis or ovary. Expression of Sry and upregulation of Sox9 are factors that initiate formation of the testis-specific pathway to allow for both sex-specific vasculature and seminiferous cord formation. Migration of mesonephric precursors of peritubular myoid cells and endothelial cells into the differentiating testis is a critical step in formation of both of these structures. Furthermore, these events appear to be initiated downstream from Sry expression. Sertoli cell secretion of growth factors acts to attract these mesonephric cells. One hypothesis is that a growth factor specific for these cell linages act in concert to coordinate migration of both peritubular and endothelial cells. A second hypothesis is that several growth factors stimulate migration and differentiation of mesonephric 'stem-like' cells to result in migration and differentiation into several different cell lineages. While the specific mechanism is unclear, several growth factors have been implicated in the initiation of mesonephric cell migration. This review will focus on the proposed mechanisms of a growth factor, Vascular Endothelial Growth Factor, and how different angiogenic and inhibitory isoforms from this single gene may aid in development of testis-specific vascular development. 相似文献
7.
Crystalline Ropes of Metallic Carbon Nanotubes 总被引:7,自引:0,他引:7
A Thess R Lee P Nikolaev H Dai P Petit J Robert C Xu YH Lee SG Kim AG Rinzler DT Colbert GE Scuseria D Tomanek JE Fischer RE Smalley 《Science (New York, N.Y.)》1996,273(5274):483-487
Fullerene single-wall nanotubes (SWNTs) were produced in yields of more than 70 percent by condensation of a laser-vaporized carbon-nickel-cobalt mixture at 1200degreesC. X-ray diffraction and electron microscopy showed that these SWNTs are nearly uniform in diameter and that they self-organize into "ropes," which consist of 100 to 500 SWNTs in a two-dimensional triangular lattice with a lattice constant of 17 angstroms. The x-ray form factor is consistent with that of uniformly charged cylinders 13.8 +/- 0.2 angstroms in diameter. The ropes were metallic, with a single-rope resistivity of <10(-4) ohm-centimeters at 300 kelvin. The uniformity of SWNT diameter is attributed to the efficient annealing of an initial fullerene tubelet kept open by a few metal atoms; the optimum diameter is determined by competition between the strain energy of curvature of the graphene sheet and the dangling-bond energy of the open edge, where growth occurs. These factors strongly favor the metallic (10,10) tube with C5v symmetry and an open edge stabilized by triple bonds. 相似文献
8.
SR Scofield CM Tobias JP Rathjen JH Chang DT Lavelle RW Michelmore BJ Staskawicz 《Science (New York, N.Y.)》1996,274(5295):2063-2065
Transient expression of the Pseudomonas syringae avirulence gene avrPto in plant cells resulted in a Pto-dependent necrosis. The AvrPto avirulence protein was observed to interact directly with the Pto resistance protein in the yeast two-hybrid system. Mutations in the Pto and avrPto genes which reduce in vivo activity had parallel effects on association in the two-hybrid assay. These data suggest that during infection the pathogen delivers AvrPto into the plant host cell and that resistance is specified by direct interaction of Pto with AvrPto. 相似文献
9.
10.
Y Tao H Chen NN Tian DT Huo G Li YH Zhang Y Liu FG Fang JP Ding XR Zhang 《Reproduction in domestic animals》2010,45(1):19-25
The maturation and developmental potential on cumulus-cell-free oocytes is of great importance theoretically and practically. The present study was to investigate the effects of l -ascorbic acid, α-tocopherol and co-culture on in vitro developmental potential of porcine denuded oocytes (DOs). Porcine DOs were cultured in maturation medium supplemented with vitamin C (0, 50, 100, 250, 500, 750 μM) and vitamin E (0, 10, 20, 50, 100, 250 μ m ), respectively. And they were also co-cultured with dispersed cumulus cells (group CCscoculture), intact cumulus cells oocyte complexes (COCs) (group COCscoculture), and COCs whose oocytes were removed (group OOXcoculture), respectively. After 44 h incubation, the maturation rates, cleavage rates and blastocyst rates after parthenogenetic activation in three experiments mentioned above were collected and analysed, respectively. L -Ascorbic acid promoted porcine DOs in vitro maturation and blastocyt development after parthenogenetic activation while α-tocopherol did not increase the in vitro maturation rates, but improved the blastocyst rate. None of the three co-culture manner promoted the in vitro maturation and the cleavage of porcine DOs after parthenogenetic activation, but all the co-culture manners improved the blastocyst rates. Both Vitamin C and E enhance the in vitro developmental potential of porcine DOs. Co-culture increases the developmental potential of porcine DOs. 相似文献