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71.
Superovulatory treatment may potentially increase the embryo recovery rate and the per-cycle pregnancy rate in normal or subfertile mares that are managed properly. However, some studies suggest a possible negative effect of superovulatory treatment on ovarian follicular maturation and embryo viability. Objectives of the present study were to investigate the early effects of eFSH treatment in reproductively normal mares in terms of: folliculogenesis, pregnancy rate, early embryonic development, reproductive tract parameters (tone and edema), and serum estradiol-17β and progesterone concentrations. Reproductively sound mares (n = 26) were evaluated daily by transrectal palpation and ultrasonography. Five days after spontaneous ovulation, mares were randomly assigned to one of two treatment groups. In the eFSH group, mares (n = 16 estrous cycles) were administered eFSH twice daily; beginning when a follicle ≥20 mm was detected, and continuing until at least one follicle reached a diameter of ≥35 mm. PGF2α was administered 2 days following initiation of eFSH therapy, and hCG was administered approximately 36 h after cessation of eFSH therapy. In the control group, mares (n = 26 estrous cycles) were administered PGF2α 7 days after spontaneous ovulation, and hCG when a follicle ≥35 mm was detected. All mares were bred with fresh semen, monitored for ovulation (Day 0), and evaluated for pregnancy on Days 11–16. Serum estradiol-17β and progesterone concentrations were analyzed using radioimmunoassay on the Day of hCG administration, and Days 8, 11 and 16. Mares treated with eFSH had more follicles ≥30 mm at the time of hCG administration (2.6 ± 0.4 compared with 1.1 ± 0.1; P < 0.01), and more ovulations (2.3 ± 0.5 compared with 1.1 ± 0.3; P < 0.01). However, pregnancy rates were not significantly different between groups (50%; 8/16 compared with 62%; 16/26). Mean overall daily growth rate of embryonic vesicles from Day 11 to 16 was not statistically different between the two groups (3.3 ± 0.3 compared with 3.7 ± 0.1 mm/day) (P = 0.2); however, was more variable (P < 0.01) in the eFSH group (95%CI: 2.6–3.8 mm/day) than in the control group (95%CI: 3.5–3.9 mm/day). Administration of eFSH modified the reproductive tract variables and serum concentrations of progesterone and estradiol-17β on the days that oocyte maturation, fertilization, and early embryonic development are expected to occur. These alterations may be related to the greater incidence of non-ovulatory follicles (25% compared with 0%), fewer embryos per ovulation rate (0.3 ± 0.1 compared with 0.6 ± 0.1), and the lesser than expected pregnancy rates in the eFSH-treated mares.  相似文献   
72.
The objective of the present study was to investigate the body-cognitive relationship through behavioral and electrophysiological measures in an attempt to uncover the underlying mediating neuronal mechanism for movement-induced cognitive change. To this end we examined the effects of Quadrato Motor Training (QMT), a new whole-body training paradigm on cognitive performance, including creativity and reaction time tasks, and electrophysiological change, using a within-subject pre-post design. Creativity was studied by means of the Alternate Uses Task, measuring ideational fluency and ideational flexibility. Electrophysiological effects were measured in terms of alpha power and coherence. In order to determine whether training-induced changes were driven by the cognitive or the motor aspects of the training, we used two control groups: Verbal Training (VT, identical cognitive training with verbal response) and Simple Motor Training (SMT, similar motor training with reduced choice requirements). Twenty-seven participants were randomly assigned to one of the groups. Following QMT, we found enhanced inter-hemispheric and intra-hemispheric alpha coherence, and increased ideational flexibility, which was not the case for either the SMT or VT groups. These findings indicate that it is the combination of the motor and cognitive aspects embedded in the QMT which is important for increasing ideational flexibility and alpha coherence.  相似文献   
73.
74.

Background

The pathogenesis of preeclampsia, a serious pregnancy disorder, is still elusive and its treatment empirical. Hypoxia Inducible Factor-1 (HIF-1) is crucial for placental development and early detection of aberrant regulatory mechanisms of HIF-1 could impact on the diagnosis and management of preeclampsia. HIF-1α stability is controlled by O2-sensing enzymes including prolyl hydroxylases (PHDs), Factor Inhibiting HIF (FIH), and E3 ligases Seven In Absentia Homologues (SIAHs). Here we investigated early- (E-PE) and late-onset (L-PE) human preeclamptic placentae and their ability to sense changes in oxygen tension occurring during normal placental development.

Methods and Findings

Expression of PHD2, FIH and SIAHs were significantly down-regulated in E-PE compared to control and L-PE placentae, while HIF-1α levels were increased. PHD3 expression was increased due to decreased FIH levels as demonstrated by siRNA FIH knockdown experiments in trophoblastic JEG-3 cells. E-PE tissues had markedly diminished HIF-1α hydroxylation at proline residues 402 and 564 as assessed with monoclonal antibodies raised against hydroxylated HIF-1α P402 or P564, suggesting regulation by PHD2 and not PHD3. Culturing villous explants under varying oxygen tensions revealed that E-PE, but not L-PE, placentae were unable to regulate HIF-1α levels because PHD2, FIH and SIAHs did not sense a hypoxic environment.

Conclusion

Disruption of oxygen sensing in E-PE vs. L-PE and control placentae is the first molecular evidence of the existence of two distinct preeclamptic diseases and the unique molecular O2-sensing signature of E-PE placentae may be of diagnostic value when assessing high risk pregnancies and their severity.  相似文献   
75.
Calatayud  A.  Iglesias  D.J.  Talón  M.  Barreno  E. 《Photosynthetica》2004,42(1):23-29
Spinach (Spinacia oleracea L. cv. Clermont) leaves grown in open-top chambers and exposed to three different concentrations of ozone were measured for gas exchange, chlorophyll a fluorescence, antioxidant systems, and lipid peroxidation at the end of growing season. High O3 concentration reduced Fv/Fm, indicating that the efficiency in the energy conversion of photosystem 2 (PS2) was altered. The rate of non-cyclic electron transport rate and the capacity to reduce the quinone pool were also affected. The development of non-photochemical quenching was not high enough to decrease the photon excess in the PS2. The limitation of photosynthetic activity was probably correlated with stomata closure and with an increase in intercellular CO2 concentration. Under oxidative stress, superoxide dismutase (SOD) activity was stimulated in parallel with lipid peroxidation. We did not find any differences in the ascorbate (AsA) pool and ascorbate peroxidase (APX) or glutathione reductase (GR) activities between air qualities. Small, but similar responses were observed in spinach leaves exposed to ambient ozone concentration.  相似文献   
76.
In experiments on unanesthetized cats, we compared the effects of experimentally induced pain in the m. biceps brachii or in the neck muscles on EMG activity of the flexors and extensors of the elbow joint (mm. biceps et triceps brachii, respectively) evoked by a passive extension-flexion of the above joint. Muscle pain was induced by injections of 0.5 ml of a hypertonic (7%) NaCl solution into the above-mentioned muscles. In the case of pain in the biceps, i.e., in the muscle directly involved in realization of the reflex, we observed an increase in the amplitude and significant shortening of the latency of EMG responses of this muscle. The amplitude of a short-latency (supposedly monosynaptic) component of the biceps reflex (М1 response) increased by 65%, while an increment of the latter (supposedly polysynaptic) М2 component was 117%. When pain was induced in anatomically remote neck muscles, the stretch reflex in the biceps was considerably suppressed. The maximum amplitudes of the М1 and М2 components decreased by 25 and 30%, respectively, but the latencies of these components decreased significantly, similarly to what was observed in the case of induction of experimental pain in the biceps. Under both conditions of experimental pain, changes in the parameters of EMG responses of the forearm extensor (m. triceps brachii) demonstrated similarity with those of the biceps responses. The maximum effect of pain induction was observed within the first 5 min after injections of the hypertonic solution; full recovery of the stretch reflex parameters was observed on the 20th to 30th min. We conclude that the effects of pain induction on the reflex under study are not generalized. They depend on the site of such induction with respect to the muscle where the stretch reflex is elicited. Unidirectional effects of both types of pain on the antagonist muscles allow us to suppose that modulation of the reflex reactions upon pain induction is mediated by influences from the supraspinal CNS structures. Induction of pain in the biceps increased the amplitude of EMG manifestations of the stretch reflex, while such induction in the neck muscles decreased such responses; nonetheless, in both cases the latency of the reflexes decreased. This fact allows us to believe that the sensitivity of muscle spindles increased under both conditions of the pain influence.  相似文献   
77.
A novel compound, radianthin, with phytotoxic activity was isolated from liquid cultures of Alternaria helianthi and identified as a pyrone related to radicinin. A second metabolite was identified as radicinin itself while deoxyradicinol is described for the first time as a natural product.  相似文献   
78.
Copper is an essential micronutrient that functions as an enzymatic cofactor in a wide range of cellular processes. Although adequate Cu levels are essential for normal metabolism, excess Cu can be toxic to cells. Cellular responses to copper deficiency and overload involve changes in the expression of genes directly and indirectly involved in copper metabolism. However little is known on the effect of physiological copper concentration on gene expression changes. In the current study we aimed to establish whether the expression of genes encoding enzymes related to cholesterol (hmgcs1, hmgcr, fdft) and fatty acid biosynthesis and LDL receptor can be induced by an iso-physiological copper concentration. The iso-physiological copper concentration was determined as the bioavailable plasmatic copper in a healthy adult population. In doing so, two blood cell lines (Jurkat and THP-1) were exposed for 6 or 24 h to iso- or supraphysiological copper concentrations. Our results indicated that in cells exposed to an iso-physiological copper concentration the early induction of genes involved in lipid metabolism was not mediated by copper itself but by the modification of the cellular redox status. Thus our results contributed to understand the involvement of copper in the regulation of cholesterol metabolism under physiological conditions.  相似文献   
79.
Tal DM  Capasso JM  Munson K  Karlish SJ 《Biochemistry》2001,40(42):12505-12514
This paper describes a novel approach to specific oxidative cleavage of Na(+),K(+)-ATPase, mediated by Cu(2+) ions and a hydrophobic phenanthroline, 4,7-diphenyl-1,10-phenanthroline (DPP), in the presence of ascorbate and H(2)O(2). The cleavage produces two major fragments of the alpha subunit, with apparent molecular masses of 96.5 and 76 kDa, and N-termini near the cytoplasmic entrance of transmembrane segments M1 and M3, respectively, The kinetics indicate that both cleavages are mediated by a single Cu(2+)-DPP complex. We infer that M3 and M1 are in proximity near the cytoplasmic surface. The yields of 96.5 and 76 kDa fragments are not significantly affected by ligands that stabilize different E(1) and E(2) conformations. In E(2)(K) and E(2)P conformations, a minor 5.5 kDa fragment with its N-terminus in M10 is also observed. The 96.5 and 76 kDa fragments are indistinguishable from two fragments near M3 and M1 produced by Fe(2+)-catalyzed cleavage described previously [Goldshleger, R., and Karlish, S. J. D. (1999) J. Biol. Chem. 274, 16213-16221], whereas other Fe(2+)-catalyzed cleavage fragments in the cytoplasmic P and A domains are not observed with the Cu(2+)-DPP complex. These findings provide experimental support for the concept of two separate Fe(2+) sites. A homology model, with Na(+),K(+)-ATPase residues within transmembrane segments and connecting loops substituted into the crystal structure of Ca(2+)-ATPase, shows the proximity between the sequences HFIH in M3 and EVWK in M1, near the cytoplasmic surface. Thus, the model strongly supports the conclusions based on cleavages mediated by the Cu(2+)-DPP complex (or Fe(2+) at site 2). As a corollary, the cleavages provide evidence for similar packing of M1 and M3 of Na(+),K(+)-ATPase and Ca(2+)-ATPase.  相似文献   
80.
Fischer rat fibroblasts, naturally resistant to killing by the fibrotropic strain of minute virus of mice [(parvovirus MVM(p)], became sensitive to MVM when transformed by polyomavirus. This sensitization did not involve an increase in the percentage of cells which synthesized viral capsid antigens or in the percentage of cells which produced infectious virus. The addition of anti-MVM antiserum to the growth medium of MVM-infected cells had only a small effect on their survival rates, indicating that the majority of the killing effect of MVM occurs in a single cycle of infection. The data indicate that cell killing by MVM is independent of infectious virus production and thus support the notion that the preferential cytolytic effect is affected by viral cytotoxic gene products which accumulate to intolerable levels in transformed cells but not in normal ones. Finally, using cells transformed with polyomavirus and genomic and subgenomic clones of polyomavirus, we showed that the extent of sensitization to killing by MVM depended on the transforming agent used.  相似文献   
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