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71.
Zinc deficiency is a critical nutritional problem in soils, restricting yield and nutritional quality of barley (Hordeum vulgare L.). Some genotypes (Zn-efficient) can produce greater yield and accumulate more Zn in seed under Zn deficiency than standard (Zn-inefficient) genotypes. However, there is little information regarding the genetics of Zn uptake/accumulation and location of genes conferring Zn efficiency in barley. Selection through molecular markers for seed Zn accumulation might be an efficient complementary breeding tool in barley. With the aim of developing molecular markers for increased accumulation of Zn in seed, a population of 150 DH lines derived from a cross between Clipper (low-Zn-accumulator) and Sahara 3771 (high-Zn-accumulator) was screened in the field and glasshouse for seed Zn concentration and content. One dominant DNA polymorphism was detected using the microsatellite-anchored fragment length polymorphism (MFLP) technique. The candidate MFLP marker was isolated from the MFLP gel, re-amplified by PCR, cloned, sequenced, and converted into simple sequence-specific and PCR-based marker. This marker, located on the short arm of chromosome 2H, might be useful for the improvement of barley nutritional quality and productivity programs in Zn-deficient environments. However, high seed Zn alone can not replace the need for Zn fertilization.  相似文献   
72.
The preparation, properties, and application in adriamycin delivery ofbiocompatible and biodegradable poly(lactide-co-glycolide)-polyethylene glycol (PLGA-PEG) nanoparticles are discussed. PLGA-PEG copolymers were synthesized by ring opening polymerization of the dl-lactide and glycolide in the presence of PEG1000. 1H-NMR and FT-IR spectrum were consistent with the structure of PLGA-PEG copolymers. The adriamycin-loaded nanoparticles could be prepared using a precipitation-solvent evaporation technique. The nanoparticles have been produced by a precipitation-solvent evaporation technique. The physical characteristics and drug loading efficiency of the PLGA-PEG nanoparticles were influenced by the composition of the PLGA-PEG copolymers used to prepare the nanoparticles. Particle sizes were between 65 and 100 nm for different compositions of PLGA-PEG copolymers. PLGA-PEG nanoparticles prepared from copolymers having relatively high PLGA/PEG ratios were smaller. Entrapment efficiency was 25%-33%. Adriamycin release from the nanoparticles at pH 7.4 showed an initial burst release and then sustained release phase. These results showed that PLGA-PEG nanoparticles could be an effective carrier for cancer therapy.  相似文献   
73.
Liver fibrosis is a disorder in which inflammatory reactions play an important role, and central to the progression and pathogenesis of this disease are the immune-specific cells known as macrophages. Macrophage types are distinguished from each other by the expression of a series of surface markers. STAT6 and Arg1 play an important role in the polarization of macrophages, so these two factors are downstream of interleukin 4 (IL-4) and IL-13 cytokines and cause to differentiate M2. Therefore, this study aimed to compare the independent effects of imatinib and mesenchymal cell treatment on the polarization of macrophages in rat models of liver fibrosis. The liver fibrosis was induced by the injection of CCL4 for 6 weeks in Sprague–Dawley rats. Then, rats were divided into four different groups, and the effects of imatinib and mesenchymal cells on the expression of Arg1, Ly6c, and STAT6 were evaluated. Histopathology experiments considered the amelioration effect of treatments. Our results showed that Arg1 expression was significantly increased in the groups treated with mesenchymal cells and imatinib compared to the control group. On the other hand, expression of STAT6 was significantly increased in the imatinib-treated mice compared to mesenchymal and control groups. Moreover, the expression of LY6C significantly decreased in imatinib and mesenchymal treated groups compared to the control group. Therefore, our data showed that mesenchymal stem cells and imatinib significantly modulate the fibrotic process in rat models of fibrosis, probably by polarizing macrophages towards an anti-inflammatory profile and increasing the frequency of these cells in liver tissue.  相似文献   
74.
75.
Angiogenesis is associated with the tissue changes underlying chronic overuse tendinopathy. We hypothesized that repetitive, cyclic loading of human tendon cells would lead to increased expression and activity of angiogenic factors. We subjected isolated human tendon cells to overuse tensile loading using an in vitro model (1 Hz, 10% equibiaxial strain). We found that mechanically stimulated human tendon cells released factors that promoted in vitro proliferation and tube formation by human umbilical vein endothelial cells (HUVEC). In response to cyclic strain, there was a transient increase in the expression of several angiogenic genes including ANGPTL4, FGF-2, COX-2, SPHK1, TGF-alpha, VEGF-A and VEGF-C, with no change in anti-angiogenic genes (BAI1, SERPINF1, THBS1 and 2, TIMP1-3). Cyclic strain also resulted in the extracellular release of ANGPTL4 protein by tendon cells. Our study is the first report demonstrating the induction of ANGPTL4 mRNA and release of ANGPTL4 protein in response to cyclic strain. Tenocytes may contribute to the upregulation of angiogenesis during the development of overuse tendinopathy.  相似文献   
76.
ObjectiveClinical studies have suggested an association between dyslipidemia and tendon injuries or chronic tendon pain; the mechanisms underlying this association are not yet known. The objectives of this study were (1) to evaluate the impact of a high fat diet on the function of load-bearing tendons and on the distribution in tendons of oxidized low density lipoprotein (oxLDL), and (2) to examine the effect of oxLDL on tendon fibroblast proliferation and gene expression.MethodsGene expression (Mmp2, Tgfb1, Col1a1, Col3a1), fat content (Oil Red O staining), oxLDL levels (immunohistochemistry) and tendon biomechanical properties were examined in mice (C57Bl/6 or ApoE -/-) receiving a standard or a high fat diet. Human tendon fibroblast proliferation and gene expression (COL1A1, COL3A1, MMP2) were examined following oxLDL exposure.ResultsIn both types of mice (C57Bl/6 or ApoE -/-), consumption of a high fat diet led to a marked increase in oxLDL deposition in the load-bearing extracellular matrix of the tendon. The consumption of a high fat diet also reduced the failure stress and load of the patellar tendon in both mouse types, and increased Mmp2 expression. ApoE -/- mice exhibited more pronounced reductions in tendon function than wild-type mice, and decreased expression of Col1a1 compared to wild type mice. Human tendon fibroblasts responded to oxLDL by increasing their proliferation and their mRNA levels of MMP2, while decreasing their mRNA levels for COL1A1 and COL3A1.ConclusionThe consumption of a high fat diet resulted in deleterious changes in tendon function, and these changes may be explained in part by the effects of oxLDL, which induced a proliferative, matrix-degrading phenotype in human tenocytes.  相似文献   
77.
Uropathogenic Escherichia coli (UPEC) bacteria are the principal cause of urinary tract infections (UTI). Because these bacteria propagate intracellularly, the cellular immune response is an important factor in UTIs. Therefore, we designed a genetic construct to induce a cellular immune response. In order to develop a genetic construct that induces strong cellular immunity against this pathogen, we used the fimH synthetic gene according to mammalian codon usage, and the gene expression was compared with wild type codon usage. Initially, we designed two constructs, pVAX/fimH mam and pVAX/fimH wt, which contain mammalian and wild type codon usage, respectively. The Cos-7 cell line was transfected separately with a complex of pVAX/fimH mam-ExGene 500 poly cationic polymer and pVAX/fimH wt-ExGene 500 poly cationic polymer. Expression of the fimH gene in both constructs in COS7 cells was confirmed by RT-PCR, SDS-PAGE, and Western blotting. Both of the pVAX/fimH cassettes expressed inserted fimH genes (mam and wt) in Cos-7 cells. Our results suggest that codon optimization successfully expressed the fimH gene because the fimH gene with mammalian codon usage is compatible with the eukaryotic expression system. Therefore, mammalian codon usage could be appropriate in a pVAX/fimH construct as a DNA vaccine.  相似文献   
78.
Statins inhibit the proximal steps of cholesterol biosynthesis, and are linked to health benefits in various conditions, including cancer and lung disease. We have previously investigated apoptotic pathways triggered by statins in airway mesenchymal cells, and identified reduced prenylation of small GTPases as a primary effector mechanism leading to p53-mediated cell death. Here, we extend our studies of statin-induced cell death by assessing endpoints of both apoptosis and autophagy, and investigating their interplay and coincident regulation. Using primary cultured human airway smooth muscle (HASM) and human airway fibroblasts (HAF), autophagy, and autophagosome formation and flux were assessed by transmission electron microscopy, cytochemistry (lysosome number and co-localization with LC3) and immunoblotting (LC3 lipidation and Atg12-5 complex formation). Chemical inhibition of autophagy increased simvastatin-induced caspase activation and cell death. Similarly, Atg5 silencing with shRNA, thus preventing Atg5-12 complex formation, increased pro-apoptotic effects of simvastatin. Simvastatin concomitantly increased p53-dependent expression of p53 up-regulated modulator of apoptosis (PUMA), NOXA, and damage-regulated autophagy modulator (DRAM). Notably both mevalonate cascade inhibition-induced autophagy and apoptosis were p53 dependent: simvastatin increased nuclear p53 accumulation, and both cyclic pifithrin-α and p53 shRNAi partially inhibited NOXA, PUMA expression and caspase-3/7 cleavage (apoptosis) and DRAM expression, Atg5-12 complex formation, LC3 lipidation, and autophagosome formation (autophagy). Furthermore, the autophagy response is induced rapidly, significantly delaying apoptosis, suggesting the existence of a temporally coordinated p53 regulation network. These findings are relevant for the development of statin-based therapeutic approaches in obstructive airway disease.  相似文献   
79.
Bats carry a variety of paramyxoviruses that impact human and domestic animal health when spillover occurs. Recent studies have shown a great diversity of paramyxoviruses in an urban-roosting population of straw-colored fruit bats in Ghana. Here, we investigate this further through virus isolation and describe two novel rubulaviruses: Achimota virus 1 (AchPV1) and Achimota virus 2 (AchPV2). The viruses form a phylogenetic cluster with each other and other bat-derived rubulaviruses, such as Tuhoko viruses, Menangle virus, and Tioman virus. We developed AchPV1- and AchPV2-specific serological assays and found evidence of infection with both viruses in Eidolon helvum across sub-Saharan Africa and on islands in the Gulf of Guinea. Longitudinal sampling of E. helvum indicates virus persistence within fruit bat populations and suggests spread of AchPVs via horizontal transmission. We also detected possible serological evidence of human infection with AchPV2 in Ghana and Tanzania. It is likely that clinically significant zoonotic spillover of chiropteran paramyxoviruses could be missed throughout much of Africa where health surveillance and diagnostics are poor and comorbidities, such as infection with HIV or Plasmodium sp., are common.  相似文献   
80.
Photosystem II is responsible for the light-driven biological water-splitting system in oxygenic photosynthesis and contains a cluster of one calcium and four manganese ions at its water-oxidizing complex. This cluster may serve as a model for the design of artificial or biomimetic systems capable of splitting water into oxygen and hydrogen. In this study, we consider the ability of manganese oxide monosheets to self-assemble with organic compounds. Layered structures of manganese oxide, including guanidinium and imidazolium groups, were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectrometry, and atomic absorption spectroscopy. The compounds can be considered as new structural models for the water-oxidizing complex of Photosystem II. The overvoltage of water oxidation for the compounds in these conditions at pH = 6.3 is ~0.6 V. These compounds may represent the first step to synthesize a hybrid of guanidinium or imidazole together with manganese as a biomimetic system for the water-oxidizing complex of Photosystem II.  相似文献   
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