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The histochemical characteristics of skeletal muscle were assessed using a range of samples from 7 appendicular muscles taken from adult mixed-breed dogs (1.5 to 3 years of age). Two slow-twitch fiber subtypes (IA and IB) and three II subtypes (IIA, IIB and IIC) were identified according to myofibrillar myosin adenosine triphosphatase reaction after acid and alkaline preincubation. Type IIB fibers were not found in all muscles, and were only biologically significant in m. semiten-dinosus. The metabolic potential of these fibers is fairly similar to that of IIA fibers, but significantly different to that of IIB fibers in other mammals, suggesting that they may be designed to play a different functional role during locomotion. All canine muscle fibers have moderate to high oxidative capacity, which may be related to the extraordinary athletic capability of the species. 相似文献
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The objectives of the present study were to investigate the relationship between the morphological status of cumulus cells surrounding canine oocytes after maturation culture and the meiotic stage of the oocytes. In addition, the effect of the removal of cumulus cells from canine cumulus-oocyte complexes (COCs) during maturation culture on their meiotic competence was examined. Canine COCs were collected from bitches at the anoestrous and dioestrous stages and only COCs with >110 microm in vitelline diameter were cultured in medium 199 with 10% canine serum for 72 h. In the first experiment, the relation between the morphological status of cumulus cells surrounding oocytes cultured for 72 h and their meiotic stages was examined. At the end of maturation culture, the proportions of intact, partially nude and completely nude oocytes were 65.2%, 22.9% and 11.9%, respectively. The proportion of maturation to metaphase II of completely nude oocytes was highest among the oocytes with different morphological status of cumulus cells. In the second experiment, the cumulus cells were partially or completely removed from COCs at 48 h after the start of maturation culture and the oocytes were cultured for a further 24 h. The proportion of oocytes reaching metaphase II in the completely denuded oocytes was significantly higher than that in the control oocytes without the removal treatment of cumulus cells. The results indicate that morphological status of cumulus cells surrounding oocytes may be related to the nuclear maturation of canine oocytes, and the removal of cumulus cells from COCs during maturation culture can promote the completion of oocyte meiotic maturation. 相似文献
95.
Methyl‐β‐Cyclodextrin Improves Sperm Capacitation Status Assessed by Flow Cytometry Analysis and Zona Pellucida‐Binding Ability of Frozen/Thawed Bovine Spermatozoa
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Mammalian sperm undergo a series of biochemical transformations in the female reproductive tract that are collectively known as capacitation. Cyclodextrins added to the sperm culture medium have been described to induce in vitro sperm capacitation, enabling its use in protein‐free media. However, the additive capacitating effect of methyl‐β‐cyclodextrin (MβCD) in the medium containing bovine serum albumin (BSA) is unknown in the bovine species. In this study, we evaluated the effects of incubating frozen–thawed bovine spermatozoa in a BSA‐containing medium supplemented with MβCD on different sperm quality and functional parameters. Sperm viability decreased with the addition of MβCD in a dose‐dependent manner (p < 0.05), and DNA damage could be observed but only with the highest concentration of MβCD. However, pre‐incubation of spermatozoa in MβCD‐supplemented medium improved the capacitation status as assessed by the increase in plasma membrane fluidity, intracellular calcium concentration, induced acrosome reactivity and zona pellucida (ZP)‐binding ability (p < 0.05). Thus, we conclude that MβCD supplementation is able to enhance the capacitation status of frozen–thawed bovine spermatozoa cultured in capacitation medium containing BSA and could result in a valid strategy for its application on artificial reproductive technologies such as in vitro fertilization or intracytoplasmic sperm injection. 相似文献
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Piza AS Pereira AR Terreran MT Mozzer O Tanuri A Brandão PE Richtzenhain LJ 《Preventive veterinary medicine》2007,78(3-4):239-245
We used a p26 recombinant protein (p26r) from equine infectious-anemia virus (EIAV) expressed in Escherichia coli as antigen to standardize an agar-gel immunodiffusion (AGIDp26r) test and an indirect ELISA (ELISAp26r) for the detection of antibodies against EIAV in 720 equine sera from Brazil. We evaluated the tests's relative diagnostic sensitivities (relSe) and relative diagnostic specificities (relSp) against a commercial AGID kit (Idexx™, USA). We used three sera panels: panel A—196 AGID-negative sera from an AIE non-endemic controlled area; panel B—194 AGID-negative sera from an AIE endemic area and panel C—330 AGID-positive sera from an AIE endemic area. ELISAp26r cut-off value was defined with TG-ROC using sera from panels A and C. AGIDp26r showed an agreement of 100% with the commercial kit. When applied to sera from panels A and C, ELISAp26r showed an agreement of 100% with the kit, but, although relSe was 100% for panel C, the ELISAp26r had relSp of 93.3%. 相似文献
99.
P Gilch F Pollinger-Dammer C Musewald ME Michel-Beyerle UE Steiner 《Science (New York, N.Y.)》1998,281(5379):982-984
The recombination dynamics of a transition metal redox system monitored by femtosecond pump-probe spectroscopy are shown to be sensitive to high magnetic fields at times shorter than 10 picoseconds. The effect, based on coherent population beats of different spin states, is quantitatively accounted for and allows direct access to spin relaxation rates far beyond the time resolution of the fastest electron paramagnetic resonance technique. The presence of this ultrafast magnetic field effect helps in understanding complex reaction schemes in transition metal chemistry, which occur in a wide range of fields, such as bioinorganic chemistry and catalysis. 相似文献
100.
Cristbal Garcs Edwin J. Niklitschek Guido Plaza Francisco Cerna Mathieu Leisen Pamela Toledo Fernando Barra 《Fisheries Oceanography》2019,28(6):735-750
Three management units (MUs) are used for stock assessment and fishery regulations of anchoveta Engraulis ringens in Chilean waters (>65% of E. ringens latitudinal range): MU‐I [18–25)°S, MU‐II [25–32)°S and MU‐III [32–42)°S. To evaluate whether these three MUs correspond to separate demographic units (DUs), as well as to estimate mixing rates and spatial distribution of these DUs, we combined three types of otolith natural markers: isotopic signatures (δ13C and δ18O), elemental compositions (Na, Mg, Mn, Sr and Ba) and microstructural indexes. All otolith markers were determined in nuclear and marginal regions of juveniles and adults from cohorts 2012 and 2015. Differences in core region markers indicated spatial segregation between three environmentally distinct nursery areas, probably related to Subtropical Water (MU‐I), Subantarctic Water (MU‐III) and the Subtropical Convergence (MU‐II). Comparison of core and marginal regions, from juvenile and/or adult fish, suggested that adult fish remained nearby nursery areas, separated from fish nursed in other MUs. Nonetheless, ontogenetic migrations from warmer (offshore) nursery habitats to cooler (deeper/more coastal) feeding habitats occurred within MUs. In summary, our results support the consideration of the three MUs as three separate DUs. Estimated mixing rates indicated MU‐II received contributions of 31% from MU‐I and 3% from MU‐III, while complete segregation existed between MU‐I and MU‐III. Such mixing rates between MU‐I and MU‐III seem large enough to justify its further consideration by stock assessment models and management procedures. 相似文献