Therapeutic hypothermia reduces intestinal ischemia/reperfusion injury after cardiac arrest in rats

To investigate the effects of therapeutic hypothermia (TH) on the morphology and function of intestine after cardiac arrest and resuscitation, 45 male rats were randomly assigned into three groups: (1) normothermia group, animals underwent ventricular fibrillation (VF) and cardiopulmonary resuscitation (CPR) with the rectal temperature maintained at 36.8 ± 0.2°C until 4 h after return of spontaneous circulation (ROSC); (2) hypothermia group, TH was induced with the aid of ice packs and an electrical fan because VF occurred and was maintained at 33.5 ± 0.5°C for 4 h after ROSC; (3) sham-operated group, animals underwent identical anesthetic and surgical procedures without VF, CPR or defibrillation. Five animals in each group were sacrificed at 4, 24 and 72 h post resuscitation. Serum diamine oxidase (DAO) and apoptosis rate of intestinal epithelial cells were tested by ELISA and flow cytometry, respectively. The concentration of FITC-Dextran that leaked out of enteric cavity was used to analyze the permeability of intestine. Histological changes were graded and compared among the three groups. Serum DAO concentrations in normothermia group reached the peak at 4 h post resuscitation, and then decreased at 24 and 72 h. In comparison with normothermia group, serum DAO concentrations were lower at 4 h in hypothermia group (0.97 ± 0.16 vs. 1.24 ± 0.29, P < 0.05). The amount of FITC-Dextran that passed the wall of small intestine in hypothermia group was significantly lower than that in normothermia group at 24 h after ROSC (7.81 ± 1.11 vs. 13.07 ± 3.07, P < 0.05). The amount of FITC-Dextran had no difference between normothermia and hypothermia groups at 4 and 72 h post resuscitation. The detached intestinal epithelial cells in hypothermia group showed  significant lower frequency of apoptosis than those in normothermia group at 4 h (17.30 ± 2.56 vs. 25.63 ± 4.09, P < 0.05) and 24 h (9.38 ± 1.29 vs. 11.98 ± 1.78, P < 0.05). No obvious injury was observed in both normothermia and hypothermia groups at 4 h with grade of 0 to 1. The histopathological injury in normothermia group reached the peak at 24 h with grade of 2 to 3, which was significantly severe than that in hypothermia group with grade of 1 to 2. At 72 h post resuscitation, an almost complete restitution of the intestinal mucous could be observed both in hypothermia and normothermia groups. This study demonstrates that short term ischemia induced by cardiac arrest and resuscitation resulted in intestinal ischemia/reperfusion (IR) injury, which could be attenuated by therapeutic hypothermia.Key words: Rat, intestine, cardiac arrest, cardiopulmonary resuscitation, therapeutic hypothermia

Novel ZnO nanorod films by chemical solution deposition for planar device applications

: Smooth and continuous ZnO films consisting of densely packed ZnO nanorods (NRs) were synthesized using hydro-thermo-chemical solution deposition method which can be used for electronic device fabrication. These devices would have the novelty of high performance benefiting from the unique properties of the nanomaterials and can be fabricated on these films using conventional low cost planar process, as they have very smooth surfaces. Photoluminescence measurements showed that the nanorod films have much stronger band-to-band emissions than those from discrete ZnO NRs, hence have the potential for the development of ZnO light emission diodes and lasers etc. The nanorod films have been used to fabricate large area planar surface acoustic wave devices by conventional photolithography and demonstrated two well-defined resonant peaks and their potential for large area device applications. The chemical solution deposition method is a simple, reproducible, scalable and economic method. These nanorod films are suitable for large scale production and synthesis on cost-effective substrates promising for various fields such as sensing systems, renewable energy and optoelectronic applications

Vertically aligned smooth ZnO nanorod films for planar device applications

The growth of smooth and continuous zinc oxide (ZnO) films, consisting of densely packed vertical ZnO nanorods with (002) crystal orientation on silicon substrates has been achieved in this work by a chemical solution method. These ZnO thin films have much stronger photoluminescence emission than those from discrete ZnO nanorods under identical conditions. Large area surface acoustic wave devices were fabricated on these films using conventional photolithography, and exhibited two well-defined resonant modes of the Sezawa wave and its harmonic mode

Determination of trace amounts of gold(III) by cathodic stripping voltammetry using a bacteria-modified carbon paste electrode

A bacteria-modified carbon paste electrode has been prepared and used for the very sensitive and selective determination of trace amounts of gold(III). The modified electrode was able to detect a solution of 1.0 ppb Au(III) by applying cathodic stripping voltammetry. Advantages of the bacteria-modified electrode include high sensitivity, good stability, low cost and simple preparation. It could be a new class of modified electrode with practical value

Intragenic DNA methylation: implications of this epigenetic mechanism for cancer research

Epigenetics is the study of all mechanisms that regulate gene transcription and genome stability that are maintained throughout the cell division, but do not include the DNA sequence itself. The best-studied epigenetic mechanism to date is DNA methylation, where methyl groups are added to the cytosine base within cytosine–guanine dinucleotides (CpG sites). CpGs are frequently clustered in high density (CpG islands (CGIs)) at the promoter of over half of all genes. Current knowledge of transcriptional regulation by DNA methylation centres on its role at the promoter where unmethylated CGIs are present at most actively transcribed genes, whereas hypermethylation of the promoter results in gene repression. Over the last 5 years, research has gradually incorporated a broader understanding that methylation patterns across the gene (so-called intragenic or gene body methylation) may have a role in transcriptional regulation and efficiency. Numerous genome-wide DNA methylation profiling studies now support this notion, although whether DNA methylation patterns are a cause or consequence of other regulatory mechanisms is not yet clear. This review will examine the evidence for the function of intragenic methylation in gene transcription, and discuss the significance of this in carcinogenesis and for the future use of therapies targeted against DNA methylation

A study of Pt4+ -adsorption and its reduction by Bacillus megaterium D01

The properties of Pt4+-adsorption and its reduction by Bacillus megaterium D01 were studied by means of ICP, anode-stripping voltammetry, TEM, IR and XPS. The results of ICP analyses showed that the Pt4+-adsorptive efficiency of the strain D01 was as high as 94.3% under the conditions of 100 mg Pt4+/L, 1 g biomass/L, pH 3.5 and at 30 degreesC for 24 h. Moreover, it was confirmed from anode stripping voltammetry that the strain D01 possessed a strong reducibility. The TEM analysis indicated that the strain D01 was able to adsorb and reduce Pt4+ to Pt-0, small particles. The XPS result further supported the reduction of Pt4+ to Pt2+, followed by the further recuction to Pt-0. The IR spectrum implied that D01 biomass adsorption of Pt4+ may result in the complexation of the C = O bond to the Pt species

A complex pattern of post‐divergence expansion, contraction, introgression and asynchronous responses to Pleistocene climate changes in two Dipelta sister species from western China

The well-known vicariance and dispersal models dominate in understanding the allopatric pattern for related species and presume the simultaneous occurrence of speciation and biogeographic events. However, the formation of allopatry may postdate the species divergence. We examined this hypothesis using DNA sequence data from 3 chloroplast fragments and 5 nuclear loci of Dipelta floribunda and D. yunnanensis, two shrub species with the circum Sichuan Basin distribution, combining the climatic niche modeling approach. The best-fit model supported by the approximate Bayesian computation (ABC) analysis indicated that, D. floribunda and D. yunnanensis diverged during the mid-Pleistocene period, consistent with the largest glacial period in the Qinghai-Tibet Plateau (QTP). The historically inter-specific gene flow was identified but seemed to have ceased after the last interglacial period (LIG), when the range of D. floribunda moved northward from the south of the Sichuan Basin. Further, populations of D. floribunda had expanded obviously in the north of the Sichuan Basin after the last glacial maximum (LGM). Relatively, the range of D. yunnanensis expanded before the LGM, reduced during the post-LGM especially in the north of the Sichuan Basin, reflecting the asynchronous responses of related species to the contemporary climate changes. Our results suggested that complex topography should be considered in understanding the distributional patterns even for closely related species and their demographic responses

Urokinase plasminogen activator secreted by cancer-associated fibroblasts induces tumor progression via PI3K/AKT and ERK signaling in esophageal squamous cell carcinoma

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Rmi1 stimulates decatenation of double Holliday junctions during dissolution by Sgs1-Top3

double Holliday junction (dHJ) is a central intermediate of homologous recombination that can be processed to yield crossover or non-crossover recombination products. To preserve genomic integrity, cells possess mechanisms to avoid crossing over. We show that Saccharomyces cerevisiae Sgs1 and Top3 proteins are sufficient to migrate and disentangle a dHJ to produce exclusively non-crossover recombination products, in a reaction termed "dissolution." We show that Rmi1 stimulates dHJ dissolution at low Sgs1-Top3 protein concentrations, although it has no effect on the initial rate of Holliday junction (HJ) migration. Rmi1 serves to stimulate DNA decatenation, removing the last linkages between the repaired and template DNA molecules. Dissolution of a dHJ is a highly efficient and concerted alternative to nucleolytic resolution that prevents crossing over of chromosomes during recombinational DNA repair in mitotic cells and thereby contributes to genomic integrity

Peptide substrate identification for yeast Hsp40 Ydj1 by screening the phage display library

We have identified a peptide substrate for molecular chaperone Hsp40 Ydj1 by utilizing the combination of phage display library screening and isothemol titration calirimetry (ITC). The initial peptide substrate screening for Hsp40 Ydj1 has been carried out by utilizing a 7-mer phage display library. The peptide sequences from the bio-panning were synthesized and object to the direct affinity measurement for Hsp40 Ydj1 by isothemol titration calirimetry studies. The peptide which has the measurable affinity with Ydj1 shows enriched hydrophobic residues in the middle of the substrate fragment. The peptide substrate specificity for molecular chaperone Hsp40 has been analyzed