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91.
92.
Human Mps1 kinase is required for the spindle assembly checkpoint but not for centrosome duplication 总被引:8,自引:0,他引:8
Budding yeast Mps1p kinase has been implicated in both the duplication of microtubule-organizing centers and the spindle assembly checkpoint. Here we show that hMps1, the human homolog of yeast Mps1p, is a cell cycle-regulated kinase with maximal activity during M phase. hMps1 localizes to kinetochores and its activity and phosphorylation state increase upon activation of the mitotic checkpoint. By antibody microinjection and siRNA, we demonstrate that hMps1 is required for human cells to undergo checkpoint arrest in response to microtubule depolymerization. In contrast, centrosome (re-)duplication as well as cell division occur in the absence of hMps1. We conclude that hMps1 is required for the spindle assembly checkpoint but not for centrosome duplication. 相似文献
93.
Gládis de Oliveira Jucoski José Cambraia Cleberson Ribeiro Juraci Alves de Oliveira Sérgio Oliveira de Paula Marco Antonio Oliva 《Acta Physiologiae Plantarum》2013,35(5):1645-1657
In excess, iron can induce the production and accumulation of reactive oxygen species (ROS), causing oxidative stress. The objective of this work was to evaluate the impact of toxic concentrations of iron (Fe) on the antioxidative metabolism of young Eugenia uniflora plants. Forty-five-day-old plants grown in Hoagland nutrient solution, pH 5.0, were treated with three Fe concentrations, in the form of FeEDTA, during three periods of time. At the end of the treatment, the plants were harvested and relative growth rate, iron content, lipid peroxidation and enzymes and metabolites of the antioxidative metabolism were determined. Iron-treated plants showed higher iron contents, reduced relative growth rates and iron toxicity symptoms in both leaves and roots. There was an increase in lipid peroxidation with increasing Fe, only in the leaves. The enzymatic activities of superoxide dismutase (SOD) and glutathione reductase (GR) increased with increasing Fe concentration and treatment exposure time. The activities of catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) also increased with increasing Fe concentration but decreased with increasing treatment exposure time. Glutathione peroxidase activity (GPX) decreased with increasing Fe concentration and exposure time. The ascorbate (AA) and reduced glutathione (GSH) contents and the AA/DHA and GSH/GSSG ratios, in general, increased with increasing Fe concentration and treatment exposure time. The results indicate that under toxic levels of Fe, young E. uniflora plants suffer increased oxidative stress, which is ameliorated through changes in the activities of antioxidative enzymes and in the contents of the antioxidants AA and GSH. 相似文献
94.
Christina Nagel Regina Erber Natascha Ille Mareike von Lewinski Jörg Aurich Erich Möstl Christine Aurich 《Theriogenology》2014
External and internal stressors prolong parturition in different species. At parturition, sympathoadrenal activation should be avoided because an increased sympathetic tone may cause uterine atonia via β2-receptors. We hypothesized that at physiological parturition, horses are under parasympathetic dominance, and stress-response mechanisms are not activated during delivery of the foal. To evaluate stress responses, heart rate, heart rate variability, catecholamines, and cortisol were analyzed in mares (n = 17) throughout foaling. Heart rate decreased from 2 hours before (51 ± 1 beats/minute) to 2 hours after delivery (41 ± 2 beats/minute; P < 0.05). Heart rate variability variables, standard deviation of the beat-to-beat interval, and root mean square of successive beat-to-beat differences, changed over time (P < 0.05) with the highest values within 15 minutes after delivery. The number of mares with atrioventricular blocks and the number of atrioventricular blocks per mare increased over time (P < 0.01) and were significantly elevated from 15 minutes before to 45 minutes after birth of the foal. Salivary cortisol concentrations increased to a maximum at 30 minutes after delivery (25.0 ± 3.4 ng/mL; P < 0.01). Plasma epinephrine and norepinephrine concentrations showed significant fluctuations from rupture of the allantochorion to expulsion of the fetal membranes (P < 0.01) but were not markedly elevated at any time. In conclusion, mares give birth under high parasympathetic tone. Cortisol release during and after foaling is most likely part of the endocrine pathways regulating parturition and not a labor-associated stress response. 相似文献
95.
Mikhajlo K. Zubko Karl Schmeer Werner E. Gläßgen E. Bayer H. Ulrich Seitz 《Plant cell reports》1993,12(10):555-558
Callus cell lines of potato (Solanum tuberosum L. cv. Zarevo) were obtained from seedlings germinated from gamma-irradiated seeds (200 Gy). Some of these cell lines produce red-violet pigments which were identified as acylated anthocyanins. The major anthocyanin was determined to be peonidin 3-O-[6-O-(4-O-E-p-coumaroyl-rhamnosyl)-glucoside]-5-O-glucoside (peonanin). Single cell-derived protoclones from non-pigmented protoplasts sometimes also gave rise to pigmented cell clusters thus indicating that the changes in the expression of the anthocyanin pathway can also occur after the stage of initial callus induction. 相似文献
96.
97.
The activities of neutral, magnesium-stimulated, and acid sphingomyelinases were measured in five regions of rat brain. Neutral enzyme activity was 2-3-fold higher in striatum than in parietal cortex and 13-fold higher than in cerebral white matter. Acid sphingomyelinase activity was more evenly distributed throughout these regions. Striatal neutral sphingomyelinase activity was not affected by treatment of rats with reserpine or haloperidol and was reduced (16%) by 6-hydroxydopamine. Striatal acid sphingomyelinase was unaffected by reserpine and 6-hydroxydopamine, and was increased (17%) by haloperidol. We conclude that neutral, magnesium-stimulated sphingomyelinase activity differs in various regions of rat brain and is particularly enriched in the corpus striatum. However, it appears to be a constitutive component of tissue rather than a readily modulated regulatory element of the catecholaminergic system. 相似文献
98.
Verena Behringer Jeroen M. G. Stevens Gottfried Hohmann Erich M?stl Dieter Selzer Tobias Deschner 《PloS one》2014,9(9)
The management of captive animals has been improved by the establishment of positive reinforcement training as a tool to facilitate interactions between caretakers and animals. In great apes, positive reinforcement training has also been used to train individuals to participate in simple medical procedures to monitor physical health. One aim of positive reinforcement training is to establish a relaxed atmosphere for situations that, without training, might be very stressful. This is especially true for simple medical procedures that can require animals to engage in behaviours that are unusual or use unfamiliar medical devices that can be upsetting. Therefore, one cannot exclude the possibility that the training itself is a source of stress. In this study, we explored the effects of medical positive reinforcement training on salivary cortisol in two groups of captive ape species, orangutans and bonobos, which were familiar to this procedure. Furthermore, we successfully biologically validated the salivary cortisol assay, which had already been validated for bonobos, for orangutans. For the biological validation, we found that cortisol levels in orangutan saliva collected during baseline conditions were lower than in samples collected during three periods that were potentially stressful for the animals. However, we did not find significant changes in salivary cortisol during medical positive reinforcement training for either bonobos or orangutans. Therefore, for bonobos and orangutans with previous exposure to medical PRT, the procedure is not stressful. Thus, medical PRT provides a helpful tool for the captive management of the two species. 相似文献
99.
Paulo Ricardo Porfírio do Nascimento Daniella Regina Arantes Martins Glória Regina Góis Monteiro Paula Vivianne Queiroz Francisco Paulo Freire-Neto José Wilton Queiroz ádila Lorena Morais Lima Selma Maria Bezerra Jeronimo 《PloS one》2013,8(10)
Leishmania infantum infection in humans and dogs can evolve with a wide range of clinical presentations, varying from asymptomatic infections to visceral leishmaniasis. We hypothesized that the immune response elicited by L. infantum infection could modulate whether the host will remain asymptomatic or progress to disease. A total of 44 dogs naturally infected with L. infantum were studied. Leishmania burden was estimated in the blood and spleen by qPCR. The expression of IFN-γ, TNF-α, IL-10 and Iron Regulatory Protein 2 (IRP2) were determined in the spleen by quantitative PCR. Sera cytokines were evaluated by ELISA. Dogs were grouped in quartiles according parasite burden. Increased expression of IFN-γ and TNF-α was associated with reduced Leishmania burden, whereas increased IL-10 and IRP2 expressions were associated with higher Leishmania load. Increased plasma albumin and IFN-γ expression explained 22.8% of the decrease in parasite burden in the spleen. These data confirm that lower IFN-γ response and higher IL-10 correlated with increased parasite load and severity of the visceral leishmaniasis in dogs. The balance between the branches of immune response and the intracellular iron availability could determine, in part, the course of Leishmania infection. 相似文献
100.
Marlene Fischer Anelia Dietmann Ronny Beer Gregor Broessner Raimund Helbok Bettina Pfausler Erich Schmutzhard Peter Lackner 《PloS one》2013,8(3)