Mesenchymal stem cells (MSCs) are candidates for cell therapy of kidney diseases. However, the application of MSC derived
from human umbilical cord (UC-MSC) in treating acute renal failure (ARF) has not been reported. UC-MSCs, 106, were transplantated via the left carotid artery into ARF rats which was established by clamping bilateral pedicles for 60 min
and reperfusing. Serum creatinine and urea nitrogen decreased 4.8 times and 3.6 times as well as caspase-3 and IL-1β decreased
5.8 times and 9 times compared to control groups, respectively. The percent of proliferative cell nuclear antigen (PCNA)-positive
cells (53% ± 7.5%) was higher than that in the control groups (17% ± 4.5%). In addition, the transplanted UC-MSCs could reside
in local injury sites, leading to the relief of hyperemia and inflammation, but no obvious transdifferentiation into renal-like
cells. The results lay the foundation for further study on the potential application of UC-MSC in human disease. 相似文献
Fungi were isolated from Meloidogyne spp. eggs and females on 102 field-collected root samples in China. Of the 235 fungi isolated (representing 18 genera and 26 species), the predominant fungi were Fusarium spp. (42.1% of the isolates collected), Fusarium oxysporum (13.2%), Paecilomyces lilacinus (12.8%), and Pochonia chlamydosporia (8.5%). The isolates were screened for their ability to parasitise Meloidogyne incognita eggs in 24-well tissue culture plates in two different tests. The percentage of eggs parasitised by the fungi, the numbers of unhatched eggs and alive and dead juveniles were counted at 4 and 7 days after inoculation. The most promising fungi included five Paecilomyces isolates, 10 Fusarium isolates, 10 Pochonia isolates and one Acremonium isolate in test 1 or test 2. Paecilomyces lilacinus YES-2 and P. chlamydosporia HDZ-9 selected from the in vitro tests were formulated in alginate pellets and evaluated for M. incognita control on tomato in a greenhouse by adding them into a soil with sand mixture at rates of 0.2, 0.4, 0.8 and 1.6% (w/w). P. lilacinus pellets at the highest rate (1.6%) reduced root galling by 66.7%. P. chlamydosporia pellets at the highest rate reduced the final nematode density by 90%. The results indicate that P. lilacinus and P. chlamydosporia as pellet formulation can effectively control root-knot nematodes. 相似文献
Increasing attention has been paid to the relationship between biodiversity and ecosystem functioning (BEF) because of the rapid increase in species loss. However, over the past 20 years, most BEF studies only focused on the effect of species diversity on one or a few ecosystem functions, and only a few studies focused on ecosystem multifunctionality (i.e., the simultaneous provision of several ecosystem functions). Grassland ecosystems have important economic, environmental, and esthetic value; thus, this study focused on the heterogeneous microcommunities in grasslands under three management modes. The multifunctionality index (M‐index) was assessed at community and microcommunity scales, and the relationship between species diversity and multifunctionality was investigated. The communities were found to be respectively composed of one, three, and six microcommunities in grazing, clipping, and enclosure management, based on a two‐way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA) for community structure. Biodiversity and soil indicators showed an apparent degradation of the grazing community, which had the worst M‐index. Clipping and enclosure communities showed no significant difference in biodiversity indices, soil variables, and M‐index; however, these indices were clearly different among microcommunities. Therefore, the microcommunity scale may be suitable to investigate the relationship between vegetation and multifunctionality in seminatural grassland ecosystems. Dominant species richness had more explanatory power for ecosystem multifunctionality than subdominant species richness, rare species richness, and the number of all species. Therefore, it is important to distinguish the role and rank of different species in the species richness–multifunctionality model; otherwise, the model might include redundant and unclear information. Communities with more codominant species whose distribution is also even might have better multifunctionality. 相似文献
The geometries and thermochemistry of Re2(NO)4(CO)n (n?=?4, 3, 2, 1, 0) structures isovalent with the binuclear cobalt carbonyls Co2(CO)n+4 have been examined using density functional theory. Eight low-energy Re2(NO)4(CO)4 structures, all with formal Re–Re single bonds, lie within 6 kcal mol?1 of the global minimum. These eight structures include unbridged structures as well as structures with two bridging NO groups but no structures with bridging CO groups. Similarly, five low-energy Re2(NO)4(CO)3 structures, all with formal Re=Re double bonds, lie within 6 kcal mol?1 of the global minimum. Again these five structures include unbridged structures as well as structures with one or two bridging NO groups but no structures with bridging CO groups. The Re2(NO)4(CO)n (n?=?4, 3) appear to be fluxional systems similar to the well-known Co2(CO)8 for which doubly bridged and unbridged structures have approximately the same energies. The lowest energy Re2(NO)4(CO)2 structures have formal Re=Re double bonds including a structure with a five-electron donor bridging η2-μ-NO group. Isomeric Re2(NO)4(CO)2 structures with formal Re≡Re triple bonds lie approximately ～10 kcal mol?1 above the global minimum. For the more highly unsaturated Re2(NO)4(CO) and Re2(NO)4 systems, the lowest energy structures have formal Re≡Re triple bonds of length ～2.6 Å. Higher energy Re2(NO)4(CO) structures have shorter Re–Re distances of length ～2.5 Å suggesting formal quadruple bonds.
Graphical Abstract The geometries and thermochemistry of Re2(NO)4(CO)n (n?=?4, 3, 2, 1, 0) structures isovalent with the binuclear cobalt carbonyls Co2(CO)n+4 have been examined using density functional theory. A number of energetically closely spaced Re2(NO)4(CO)4 and Re2(NO)4(CO)3 structures are found, including unbridged and NO-bridged structures but no CO-bridged structures. The Re2(NO)4(CO)n (n?=?2, 1, 0) systems provide examples of Re–Re multiple bonds of orders ranging from 2 to 4.
While the molecular mechanisms by which oxidants cause cytotoxicity are still poorly understood, disruption of Ca(2+) homeostasis appears to be one of the critical alterations during the oxidant-induced cytotoxic process. Here, we examined the possibility that oxidative stress may alter the metabolism of cyclic ADP-ribose (cADPR), a potent Ca(2+)-mobilizing second messenger in the heart. Isolated heart perfused by Langendorff technique was subjected to ischemia/reperfusion injury and endogenous cADPR level was determined using a specific radioimmunoassay. Following ischemia/reperfusion injury, a significant increase in intracellular cADPR level was observed. The elevation of cADPR content was closely correlated with the increase in ADP-ribosyl cyclase activity. Inclusion of oxygen free radical scavengers, 2,2,6,6-tetramethyl-1-piperidinyloxy and mannitol, in the reperfusate prevented the ischemia/reperfusion-induced increases in cADPR level and the ADP-ribosyl cyclase activity. Exposure of isolated cardiomyocytes to t-butyl hydroperoxide increased the ADP-ribosyl cyclase activity, cADPR level, and intracellular Ca(2+) concentration ([Ca(2+)](i)) and consequently resulting in cell lethal damage. The oxidant-induced elevation of [Ca(2+)](i) as well as cell lethal damage was blocked by a cADPR antagonist, 8-bromo-cADPR. These results provide evidence for involvement of cADPR and its producing enzyme in alteration of Ca(2+) homeostasis during the ischemia/reperfusion injury of the heart. 相似文献
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