272 research outputs found
Study of Antenna Superstrates Using Metamaterials for Directivity Enhancement Based on Fabry-Perot Resonant Cavity
Metamaterial superstrate is a significant method to obtain high directivity of one or a few antennas. In this paper, the characteristics of directivity enhancement using different metamaterial structures as antenna superstrates, such as electromagnetic bandgap (EBG) structures, frequency selective surface (FSS), and left-handed material (LHM), are unifiedly studied by applying the theory of Fabry-Perot (F-P) resonant cavity. Focusing on the analysis of reflection phase and magnitude of superstrates in presently proposed designs, the essential reason for high-directivity antenna with different superstrates can be revealed in terms of the F-P resonant theory. Furthermore, a new design of the optimum reflection coefficient of superstrates for the maximum antenna directivity is proposed and validated. The optimum location of the LHM superstrate which is based on a refractive lens model can be determined by the F-P resonant distance
Concomitant hypermethylation of multiple genes in non-small cell lung cancer (NSCLC)
Primary lung cancer remains the leading cause of cancer death worldwide. Promoter hypermethylation
is a major inactivation mechanism of tumor-related genes, and increasingly appears to play an important
role in carcinogenesis. In the present study, we used quantitative methylation-specific PCR (Q-MSP) assays to
analyze promoter hypermethylation of nine genes in a large cohort of well-characterized non-small cell lung
cancer (NSCLC) and explore their associations with the clinicopathological features of tumor. We found that
there were significant differences in methylation levels for six of nine gene promoters between cancerous and
noncancerous lung tissues. More importantly, with 100% diagnostic specificity, high sensitivity, ranging from
44.9% to 84.1%, was found for each of the nine genes. Interestingly, promoter hypermethylation of most genes
was closely associated with histologic type, which was more frequent in squamous cell carcinomas (SCC) than in
adenocarcinomas (ADC). In addition, highly frequent concomitant methylation of multiple genes was found in
NSCLC, particularly in SCC. Our data showed that multiple genes were aberrantly methylated in lung tumorigenesis,
and that they were closely associated with certain clinicopathological features of NSCLC, particularly of
the histologic type, suggesting that these hypermethylated genes could be potential biomarkers in early detection
of NSCLC in high-risk individuals, as well as in evaluating the prognosis of NSCLC patients. (Folia Histochemica
et Cytobiologica 2011, Vol. 49, No. 1, 132–141
Highly frequent promoter methylation and PIK3CA amplification in non-small cell lung cancer (NSCLC)
<p>Abstract</p> <p>Background</p> <p>Lung cancer is the leading cause of cancer-related death worldwide. Genetic and epigenetic alterations have been identified frequently in lung cancer, such as promoter methylation, gene mutations and genomic amplification. However, the interaction between genetic and epigenetic events and their significance in lung tumorigenesis remains poorly understood.</p> <p>Methods</p> <p>We determined the promoter methylation of 6 genes and <it>PIK3CA </it>amplification using quantitative methylation-specific PCR (Q-MSP) and real-time quantitative PCR, respectively, and explore the association of promoter methylation with <it>PIK3CA </it>amplification in a large cohort of clinically well-characterized non-small cell lung cancer (NSCLC).</p> <p>Results</p> <p>Highly frequent promoter methylation was observed in NSCLC. With 100% diagnostic specificity, excellent sensitivity, ranging from 45.8 to 84.1%, was found for each of the 6 genes. The promoter methylation was associated with histologic type. Methylation of <it>CALCA, CDH1, DAPK1</it>, and <it>EVX2 </it>was more common in squamous cell carcinomas (SCC) compared to adenocarcinomas (ADC). Conversely, there was a trend toward a higher frequency of <it>RASSF1A </it>methylation in ADC than SCC. In addition, <it>PIK3CA </it>amplification was frequently found in NSCLC, and was associated with certain clinicopathologic features, such as smoking history, histologic type and pleural indentation. Importantly, aberrant promoter methylation of certain genes was significantly associated with <it>PIK3CA </it>amplification.</p> <p>Conclusions</p> <p>Our data showed highly frequent promoter methylation and <it>PIK3CA </it>amplification in Chinese NSCLC population, and first demonstrated the associations of gene methylation with <it>PIK3CA </it>amplification, suggesting that these epigenetic events may be a consequence of overactivation of PI3K/Akt pathway.</p
Diverse biological effects of glycosyltransferase genes from Tartary buckwheat
Background: Tartary buckwheat (Fagopyrum tataricum) is an edible cereal crop whose sprouts have been marketed and commercialized for their higher levels of anti-oxidants, including rutin and anthocyanin. UDP-glucose flavonoid glycosyltransferases (UFGTs) play an important role in the biosynthesis of flavonoids in plants. So far, few studies are available on UFGT genes that may play a role in tartary buckwheat flavonoids biosynthesis. Here, we report on the identification and functional characterization of seven UFGTs from tartary buckwheat that are potentially involved in flavonoid biosynthesis (and have varying effects on plant growth and development when overexpressed in Arabidopsis thaliana.)
Results: Phylogenetic analysis indicated that the potential function of the seven FtUFGT proteins, FtUFGT6, FtUFGT7, FtUFGT8, FtUFGT9, FtUFGT15, FtUFGT40, and FtUFGT41, could be divided into three Arabidopsis thaliana functional subgroups that are involved in flavonoid biosynthesis of and anthocyanin accumulation. A significant positive correlation between FtUFGT8 and FtUFGT15 expression and anthocyanin accumulation capacity was observed in the tartary buckwheat seedlings after cold stress. Overexpression in Arabidopsis thaliana showed that FtUFGT8, FtUFGT15, and FtUFGT41 significantly increased the anthocyanin content in transgenic plants. Unexpectedly, overexpression of FtUFGT6, while not leading to enhanced anthocyanin accumulation, significantly enhanced the growth yield of transgenic plants. When wild-type plants have only cotyledons, most of the transgenic plants of FtUFGT6 had grown true leaves. Moreover, the growth speed of the oxFtUFGT6 transgenic plant root was also significantly faster than that of the wild type. At later growth, FtUFGT6 transgenic plants showed larger leaves, earlier twitching times and more tillers than wild type, whereas FtUFGT15 showed opposite results.
Conclusions: Seven FtUFGTs were isolated from tartary buckwheat. FtUFGT8, FtUFGT15, and FtUFGT41 can significantly increase the accumulation of total anthocyanins in transgenic plants. Furthermore, overexpression of FtUFGT6 increased the overall yield of Arabidopsis transgenic plants at all growth stages. However, FtUFGT15 shows the opposite trend at later growth stage and delays the growth speed of plants. These results suggested that the biological function of FtUFGT genes in tartary buckwheat is diverse
Loureirin B attenuates amiodarone-induced pulmonary fibrosis by suppression of TGFβ1/Smad2/3 pathway
Purpose: To investigate the therapeutic effect of loureirin B (LB) on amiodarone (AD)-induced pulmonary fibrosis (PF).Methods: Forty-eight male C57BL/6 mice, 8–10 weeks of age, were divided into four groups (n=12). Oral administration of amiodarone hydrochloride (AD) was performed for 4 weeks to induce pulmonary fibrosis. The degree of fibrosis was assessed by Masson staining, while collagen I and α-smooth muscle actin (α-SMA) levels were evaluated by Western blot analysis. ELISA was used to measure the levels of cytokines TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF) and lung tissue. Levels of p- Smad2, Smad2, p-Smad3 and Smad3 were determined by western blotting.Results: AD treatment increased the collagen levels and expression levels of collagen I and α-smooth muscle actin (α-SMA) in lung tissue and of inflammatory cytokines TNF-α, IL-1β, and IL-6, in both bronchoalveolar lavage fluid (BALF) and lung tissue in a dose-dependent manner (p < 0.01).Furthermore, AD increased the levels of p-Smad2/3. AD-induced increases in collagen I and α-SMA levels were reversed by loureirin B (LB). In addition, LB reduced AD-induced increased levels of the inflammatory cytokines TNF-α, IL-1β, and IL-6 in both bronchoalveolar lavage fluid (BALF) and lung tissue (p < 0.01).Conclusion: These results demonstrate that LB downregulates expression of fibrosis-related proteins and suppresses AD-induced PF. The mechanism responsible for the protective effect of LB on ADinduced PF might involve inhibition of the Smad2/3 pathway. Thus, LB is a potential therapeutic agent for the management of PF.
Keywords: Amiodarone, Loureirin B, Pulmonary fibrosis, Smad, Inflammatio
Aloperine attenuates carbon tetrachloride-induced mouse hepatic injury via Nrf2/HO-1 pathway
Purpose: To investigate whether aloperine pretreatment ameliorates acute liver injury in carbon tetrachloride (CCl4)-treated mice.Methods: Mice were injected with CCl4 and orally administered aloperine. Blood samples and liver tissues were used for histopathological and biochemical analyses, respectively. Protein expression levels were determined by western blotting.Results: Histopathological analysis indicate that aloperine pretreatment significantly alleviated CCl4- induced mouse hepatic injury. CCl4 treatment induced the upregulation of aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine amino transferase (ALT), and total bilirubin (p < 0.05). However, these alterations were significantly inhibited by aloperine treatment. Moreover, aloperine pretreatment markedly decreased (p < 0.05) the CCl4-induced expression of oxidative stress biomarkers, including malondrialdeline (MDA), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Compared to the control group, the protein levels of Nrf2, HO-1, iNOS, and COX-2 were significantly increased in the CCl4 group, while Nrf2 and HO-1 were upregulated. Furthermore, iNOS and COX-2 were downregulated in mouse liver in CCl4 + aloperine group compared to CCl4 group in a concentration-dependent manner (p < 0.05).Conclusion: Aloperine pretreatment appears to markedly upregulate Nrf2 and HO-1 and downregulate iNOS and COX-2 to suppress hepatic injury in mice. Thus, aloperine is a promising treatment for acute liver injury.
Keywords: Hepatic injury, Aloperine, Oxidative stress, Nrf2/HO-1 pathwa
OR-028 Ageing effect of muscular athletic capability in knee joints over healthy woman aged 45 - 64 years
Objective It is important to evaluate the effect of age on muscular athletic capability in knee joints over healthy woman aged 45 to 64. The research could provide female ageing effect on muscular athletic capability for elderly persons, aiming to promote the relative research on exercise improvement and Women's health.
Methods A total of 126 volunteers were selected. The knee muscle strength indexes were tested on side-to-side using self-developed digital isometric muscle function test system. Main indexes include muscle strength, muscle explosive force and muscle endurance on side-to-side. The age groups are classified with 5 years intervals recommended by WHO. The statistics of trend, correlation network, ANOVA and PCA were employed to distinguish the aging effects. All test were implemented in R platform (version 3.3.3).
Results (1) muscle strength showed obvious differences between left and right; the relative higher explosive force occurred with extensor muscles on the left showing the significant changing point at 100 ms after 50; the muscle endurance and fatigue index showed side differences after 60. (2) muscle strength trend showed “down then up” characteristics with the slightly ahead of 55 on the right side as well as muscle endurance indexes. (3) indexes between explosive force variables showed strong significant difference (p<0.001) while muscle fatigue indexes showed side differences; muscle strength in flexor muscles displayed significant correlations with explosive force variables on the right but opposite in extensor muscles on the left. (4) the huge difference occurred in extensor groups especially the comparison between minimum and maximum groups. (5) the main influences on knee muscular athletic capability include explosive force variables as well as muscle fatigue index.
Conclusions Both ageing effect and side effect are observed in muscular athletic capability in knee joints over healthy woman aged 45 - 64 years. After 55, the related variables showed decrease trend indicating the potential decreased muscular athletic capability. In both flexor and extensor muscles, strength variables displayed significant side differences, showing high explosive force in flexor muscles on the right side. The crucial age 50 and 55 became the turning points for knee muscular athletic capability especially with explosive forces
Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice
The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg−1 and (v) 2.00 g kg−1 black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23–27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities
Characterization of a Novel Nicotine Degradation Gene Cluster ndp in Sphingomonas melonis TY and Its Evolutionary Analysis
Sphingomonas melonis TY utilizes nicotine as a sole source of carbon, nitrogen, and energy through a variant of the pyridine and pyrrolidine pathways (VPP). A 31-kb novel nicotine-degrading gene cluster, ndp, in strain TY exhibited a different genetic organization with the vpp cluster in strains Ochrobactrum rhizosphaerae SJY1 and Agrobacterium tumefaciens S33. Genes in vpp were separated by a 20-kb interval sequence, while genes in ndp were localized together. Half of the homolog genes were in different locus in ndp and vpp. Moreover, there was a gene encoding putative transporter of nicotine or other critical metabolite in ndp. Among the putative nicotine-degrading related genes, the nicotine hydroxylase, 6-hydroxy-L-nicotine oxidase, 6-hydroxypseudooxynicotine oxidase, and 6-hydroxy-3-succinyl-pyridine monooxygenase responsible for catalyzing the transformation of nicotine to 2, 5-dihydropyridine in the initial four steps of the VPP were characterized. Hydroxylation at C6 of the pyridine ring and dehydrogenation at the C2–C3 bond of the pyrrolidine ring were the key common reactions in the VPP, pyrrolidine and pyridine pathways. Besides, VPP and pyrrolidine pathway shared the same latter part of metabolic pathway. After analysis of metabolic genes in the pyridine, pyrrolidine, and VPP pathways, we found that both the evolutionary features and metabolic mechanisms of the VPP were more similar to the pyrrolidine pathway. The linked ndpHFEG genes shared by the VPP and pyrrolidine pathways indicated that these two pathways might share the same origin, but variants were observed in some bacteria. And we speculated that the pyridine pathway was distributed in Gram-positive bacteria and the VPP and pyrrolidine pathways were distributed in Gram-negative bacteria by using comprehensive homologs searching and phylogenetic tree construction
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