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1.
目的:研究大鼠脑缺血/再灌注过程中血流量及与脑组织水含量变化的趋势。方法:选取5只成年SD雄性大鼠(n=5),参照改良Zea-Longa线栓法制备大鼠大脑中动脉缺血/再灌注模型,2 h后拔出线栓。利用PeriCam PSI血流灌注成像系统实时监测大鼠在缺血前及缺血5 min、30 min、1 h、2 h、再灌注5 min、30 min、1 h、2 h、4 h、6 h及24 h的血流灌注量,记录在ROI(感兴趣区)测量的数值。再选取15只成年SD雄性大鼠,分为Control组、缺血2 h、再灌注30 min、4 h及24 h组(n=3)。正常组不做任何处理,实验组按上述线栓法制备MCAO模型。取新鲜脑组织用干湿重法测定其左、右半球的水含量。结果:栓塞时缺血侧血流量逐渐下降,缺血2 h下降最低(P<0.05);再灌注早期血流量恢复较大(P<0.05),30 min时显著下降(P<0.05),4 h明显上升(P<0.05),24 h再次上升(P<0.05)但低于缺血前血流量(P>0.05)。脑组织水含量测量,缺血2 h组和再灌注30 min组与正常组无明显差异(P>0.05);再灌4 h组和再灌24 h组明显增高(P<0.05),且再灌24 h组明显高于再灌4 h组(P<0.05)。结论:大鼠脑缺血/再灌注过程中血流量和脑组织中水含量的变化存在一定的规律,且脑组织中水含量与再灌注过程中血流量的变化有一定关系。 相似文献
2.
MNK Clottey R Asmah PK Ofori-Danson MY Ameworwor AY Karikari 《African Journal of Aquatic Science》2016,41(4):473-480
The effects of cage fish farming on physico-chemical and bacteriological water quality in Lake Volta, Ghana, were investigated in 2013–2014. Farmed and unfarmed (control) areas of the lake were selected for monitoring. Nutrients, temperature, dissolved oxygen, conductivity, turbidity, pH, total coliforms, Pseudomonas and Vibrio spp. in the water were monitored monthly. Analyses of the water samples were carried out according to standard procedures. Physico-chemical quality of the water in both farm and control sites were within ranges typical of minimally impacted water and did not vary significantly between the two contrasting sites. The bacteriological analysis, however, revealed contamination of the lake water by fish farming. The bacterial counts at the farmed sites were significantly higher (p < 0.05) than those of the control sites, with figures at the farmed sites ranging from 132 to 1 708 cfu 100 ml?1 for total coliforms, 514 to 5 170 cfu 100 ml?1 Pseudomonas spp. and 14 to 516 cfu 100 ml?1 for Vibrio spp. The results suggested that cage fish farming has increased bacterial loads in the lake water, but has had minimal impact on its physico-chemical quality. 相似文献
3.
This paper presents the work conducted on the
chemical constituents of some common and widely distributed
halophyte taxa from Cyprus with the aim that these studies will
help in the evaluation of halophytes for different economical
purposes. The plant species of Crithmum maritimum L., Limbarda
crithmoides (L.) Dumort, Atriplex portulacoides L., Salsola kali L.,
Atriplex halimus L., Limonium oleifolium Mill., L. meyeri (Boiss.)
Kuntze; and Tetraena alba (L.f.) Beier & Thulin were collected
in the middle of July. The shoot tissue and leaf samples were
collected from the natural habitats and left for drying under air
circulation followed by placing them in oven at 60 °C for 96
hours. The material was crushed using mortar and pestle and
subjected to an analysis of macro- and micro-nutrients and
biochemical compounds. K+/Na+ in the leaf tissues of the dicot
species showed relatively high values depicting their behavior
as Na+ includes but very low Cl- levels were recorded. Out of
the species investigated here in 4 TFAA content was rather high.
Values ranging from 0.5% to 1% dry weight were exhibited in one
species. However, only 3 species showed very low TFAA values.
Later may be due to low nitrogen availability in their environment.
The phenetic analyses of eight halophyte species performed on
the data matrix using Ntsys-pc program version 2.1 revealed
that, cluster analysis of the overall results obtained here leads to
2 clusters. This discrimination appears to be as a result of their
different abilities to accumulate either proline or glycine betaine. 相似文献
4.
Mitsuomi?Shimazakimitujin@fish.hokudai.ac.jp; MY myabe@fish.hokudai.ac.jp" title="MS mitujin@fish.hokudai.ac.jp; MY myabe@fish.hokudai.ac.jp" itemprop="email" data-track="click" data-track-action="Email author" data-track-label="">Email author Hiromitsu?Endo Mamoru?Yabe 《Ichthyological Research》2004,51(2):120-125
Halieutopsis bathyoreos Bradbury, 1988 (Lophiiformes: Ogcocephalidae), previously described only on the basis of the holotype (62.6mm in standard length) from the central North Pacific, is redescribed on the basis of the holotype and six additional specimens (41.2–68.7mm in standard length) collected from the western South Pacific, off Papua New Guinea, and the western North Pacific, including the Japanese Archipelago. Halieutopsis bathyoreos is distinguished from its congeners by having a shelflike rostrum extending anteriorly well beyond the mouth, a dorsal escal lobe slightly bisected ventrally, an illicial cavity square in outline and completely visible in ventral view, and lacking tubercles on the ventral surface of the disk. The following characters are newly added to the diagnoses of this species: rostrum width 21–29% of head length, tubercles on the dorsal surface of the disk about half the diameter of those on the lateral margin, and 13–15 large lateral-line scales on the tail. 相似文献
5.
Trubetskaia VV Stepanichev MIu Onufriev MV Lazareva NA Markevich VA Guliaeva NV 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2001,51(6):690-693
A month after intracerebroventricular injection of aggregated beta-amyloid fragment 25-35 (7.5 nmol/ventricle), a significant change in in vivo long-term potentiation in hippocampus was demonstrated. The time course of the long-term potentiation was compared with that in sham-operated animals, a powerful and stable increase in the evoked potential amplitude was observed. This phenomenon can be related with the oxidative stress that was revealed in this model in our previous studies, and, as a consequence, with deterioration of ion homeostasis. 相似文献
6.
Kudriashova IV Stepanichev MIu Guliaeva NV 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2007,57(6):702-711
Previously the developmental switch to caspase-3 activation in the rat hippocampus has been shown during the third week of life. The goal of this study was to explore effects of caspase-3 inhibition during this period on learning in a two-way avoidance paradigm. On postnatal day 18, the pups were intracerebroventricularly administered with caspase-3 inhibitor Z-DEVD-FMK. Control groups were injected with either the control peptide Z-FA-FMK or saline. Caspase-3 inhibition, naturally activated in this critical period, was found to disturb the maturation of instrumental behavior. In particular, the young adult rats of Z-DEVD-FMK group displayed less effective elaboration of escape and active avoidance reactions in two-way avoidance paradigm, accompanied with a decrease in inter-trial crossings. However, associative components of the learning did not change after caspase-3 inhibition. Conditioned emotional behavior was, in general, similar in all groups, and the number of responses related to conditioned stimulus exploration did not differ in Z-DEVD-FMK and Z-FA-FMK groups. In spite of the deficit in active avoidance conditioning in Z-DEVD-FMK group, a significant increase in incomplete or preparatory reactions to conditioned stimulus was demonstrated suggesting that the association between predictive conditioned stimulus and possibility of crossing can be elaborated. The change of exploratory behavior is unlikely to be specific for caspase-3 inhibition, being similar in Z-DEVD-FMK and Z-FA-FMK groups. 相似文献
7.
1. Decomposition of litter mixtures in both terrestrial and aquatic ecosystems often shows non‐additive diversity effects on decomposition rate, generally interpreted in streams as a result of the feeding activity of macroinvertebrates. The extent to which fungal assemblages on mixed litter may influence consumption by macroinvertebrates remains unknown. 2. We assessed the effect of litter mixing on all possible three‐species combinations drawn from four tree species (Alnus glutinosa, Betula pendula, Juglans regia and Quercus robur) on both fungal assemblages and the rate of litter consumption by a common shredder, Gammarus fossarum. After a 9‐week inoculation in a stream, batches of leaf discs were taken from all leaf species within litter mixture combinations. Ergosterol, an indicator of fungal biomass, and the composition of fungal assemblages, assessed from the conidia released, were determined, and incubated litter offered to G. fossarum in a laboratory‐feeding experiment. 3. Mixing leaf litter species enhanced both the Simpson’s index of the fungal assemblage and the consumption of litter by G. fossarum, but had no clear effect on mycelial biomass. Specifically, consumption rates of J. regia were consistently higher for mixed‐species litter packs than for single‐species litter. In contrast, the consumption rates of B. pendula were not affected by litter mixing, because of the occurrence of both positive and negative litter‐mixing effects in different litter species combinations that counteracted each other. 4. In some litter combinations, the greater development of some fungal species (e.g. Clavariopsis aquatica) as shown by higher sporulation rates coincided with increased leaf consumption, which may have resulted from feeding preferences by G. fossarum for these fungi. 5. Where litter mixture effects on decomposition rate are mediated via shredder feeding, this could be due to indirect effects of the fungal assemblage. 相似文献
8.
The coup de grâce for the nested clade phylogeographic analysis? 总被引:5,自引:4,他引:1
RÉMY J. PETIT 《Molecular ecology》2008,17(2):516-518
Nested clade phylogeographic analysis (NCPA) has become a popular method for reconstructing the history of populations across species ranges. Ever since its invention in 1995, criticisms have been formulated, but the method, which has been regularly updated, continues to attract investigators. Molecular Ecology has published a large fraction of the literature on the topic — both pro and con. A recent study by Panchal and Beaumont (2007) finally allows a precise evaluation of the method by developing software that automates the somewhat complicated NCPA procedure. Using simulations of random-mating populations, Panchal and Beaumont find a high frequency of false-positives with their automated NCPA procedure (over 75%). These findings, which echo and amplify earlier warnings, appear serious enough to suggest to researchers to await further evaluation of the method. Although no other all-encompassing method such as the NCAP currently exists to evaluate phylogeographic data sets, researchers have many alternative methods to test ever more refined hypotheses. 相似文献
9.
10.
Chuan-Ming Xie Xiao-Yu Liu Kathy WY Sham Josie MY Lai Christopher HK Cheng 《Autophagy》2014,10(9):1495-1508
EEF2K (eukaryotic elongation factor-2 kinase), also known as Ca2+/calmodulin-dependent protein kinase III, functions in downregulating peptide chain elongation through inactivation of EEF2 (eukaryotic translation elongation factor 2). Currently, there is a limited amount of information on the promotion of autophagic survival by EEF2K in breast and glioblastoma cell lines. However, the precise role of EEF2K in carcinogenesis as well as the underlying mechanism involved is still poorly understood. In this study, contrary to the reported autophagy-promoting activity of EEF2K in certain cancer cells, EEF2K is shown to negatively regulate autophagy in human colon cancer cells as indicated by the increase of LC3-II levels, the accumulation of LC3 dots per cell, and the promotion of autophagic flux in EEF2K knockdown cells. EEF2K negatively regulates cell viability, clonogenicity, cell proliferation, and cell size in colon cancer cells. Autophagy induced by EEF2K silencing promotes cell survival and does not potentiate the anticancer efficacy of the AKT inhibitor MK-2206. In addition, autophagy induced by silencing of EEF2K is attributed to induction of protein synthesis and activation of the AMPK-ULK1 pathway, independent of the suppression of MTOR activity and ROS generation. Knockdown of AMPK or ULK1 significantly abrogates EEF2K silencing-induced increase of LC3-II levels, accumulation of LC3 dots per cell as well as cell proliferation in colon cancer cells. In conclusion, silencing of EEF2K promotes autophagic survival via activation of the AMPK-ULK1 pathway in colon cancer cells. This finding suggests that upregulation of EEF2K activity may constitute a novel approach for the treatment of human colon cancer. 相似文献