31 research outputs found

    Tree Ring Characteristics of 30-Year-Old Swietenia Macrophylla Plantation Trees

    Get PDF
    Ring characteristics of mahogany (Swietenia macrophylla K.) plantation trees grown in Taiwan were explored. Significant differences in average ring width (RW) and ring density (RD) occurred among three tree-diameter classes and three radial stages of ring numbers. RW in the radial direction decreased from the pith outward to the bark and followed a distinctive three-stage variation pattern (juvenile, transition, and mature zones). RD in the radial direction increased slowly from the pith outward to the bark. Wider tree rings and lower density are associated with juvenile wood close to the pith, whereas narrower tree rings and higher density are typical for mature wood outward toward the bark. RD in overtopped trees was higher than that in dominant trees. However, RW in dominant trees was wider than that in intermediate and overtopped trees. Earlywood density, latewood density, maximum density, and minimum density were the most important factors determining overall RD. There was a weak relationship between RW and RD, indicating that it is unlikely for growth rates of mahogany plantation trees to have a significant impact on wood density

    KCNN2 polymorphisms and cardiac tachyarrhythmias

    Get PDF
    Potassium calcium-activated channel subfamily N member 2 (KCNN2) encodes an integral membrane protein that forms small-conductance calcium-activated potassium (SK) channels. Recent studies in animal models show that SK channels are important in atrial and ventricular repolarization and arrhythmogenesis. However, the importance of SK channels in human arrhythmia remains unclear. The purpose of the present study was to test the association between genetic polymorphism of the SK2 channel and the occurrence of cardiac tachyarrhythmias in humans. We enrolled 327 Han Chinese, including 72 with clinically significant ventricular tachyarrhythmias (VTa) who had a history of aborted sudden cardiac death (SCD) or unexplained syncope, 98 with a history of atrial fibrillation (AF), and 144 normal controls. We genotyped 12 representative tag single nucleotide polymorphisms (SNPs) across a 141-kb genetic region containing the KCNN2 gene; these captured the full haplotype information. The rs13184658 and rs10076582 variants of KCNN2 were associated with VTa in both the additive and dominant models (odds ratio [OR] 2.89, 95% confidence interval [CI] = 1.505-5.545, P = 0.001; and OR 2.55, 95% CI = 1.428-4.566, P = 0.002, respectively). After adjustment for potential risk factors, the association remained significant. The population attributable risks of these 2 variants of VTa were 17.3% and 10.6%, respectively. One variant (rs13184658) showed weak but significant association with AF in a dominant model (OR 1.91, CI = 1.025-3.570], P = 0.042). There was a significant association between the KCNN2 variants and clinically significant VTa. These findings suggest an association between KCNN2 and VTa; it also appears that KCNN2 variants may be adjunctive markers for risk stratification in patients susceptible to SCD

    Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

    Get PDF
    Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase

    Optimizing the Ultrasound Image Quality of Carotid Artery Stenosis Patients via Taguchi’s Dynamic Analysis and an Indigenous Water Phantom

    No full text
    This study optimized the ultrasound image of carotid artery stenosis using Taguchi dynamic analysis and an indigenous water phantom. Eighteen combinations of seven essential factors of the ultrasound scan facility were organized according to Taguchi’s L18 orthogonal array. The seven factors were assigned as follows: (1) angle of probe; (2) signal gain; (3) resolution vs. speed; (4) dynamic range; (5) XRES; (6) zoom; (7) time gain compensation. An indigenous water phantom was customized to satisfy the quantified need in Taguchi’s analysis. Unlike the conventional dynamic Taguchi analysis, an innovative quantified index, the figure of merit (FOM), was proposed to integrate four specific quality characteristics, namely (i) average difference between the practical scan and theoretically preset area (78.5, 50.2 and 12.6 mm2) of stenosis, (ii) standard deviation of the average, (iii) practical scan’s sensitivity β to various stenosis diameters (10, 8, and 4 mm), and (iv) correlation coefficient r2 of the linear regressed sensitivity curve. The highest value (FOM = 0.413) was furnished by the optimal combination of factors on 18 groups under study, yielding high r2 and low β or standard deviation values and the best quality of ultrasound images for the further clinical diagnosis. The comparison between FOM and the conventional signal-to-noise (S/N) ratio in Taguchi’s analysis revealed that FOM compiled more quality characteristics that were superior by nature to fulfill the practical need in clinical diagnosis. The alternative choice in ultrasound scan optimization can be based on stenosis diameter variation from a different perspective to be explored in the follow-up study

    Capsaicin Induces Autophagy and Apoptosis in Human Nasopharyngeal Carcinoma Cells by Downregulating the PI3K/AKT/mTOR Pathway

    No full text
    Capsaicin is a potential chemotherapeutic agent for different human cancers. In Southeast China, nasopharyngeal carcinoma (NPC) has the highest incidence of all cancers, but final treatment outcomes are unsatisfactory. However, there is a lack of information regarding the anticancer activity of capsaicin in NPC cells, and its effects on the signaling transduction pathways related to apoptosis and autophagy remain unclear. In the present study, the precise mechanisms by which capsaicin exerts anti-proliferative effects, cell cycle arrest, autophagy and apoptosis were investigated in NPC-TW01 cells. Exposure to capsaicin inhibited cancer cell growth and increased G1 phase cell cycle arrest. Western blotting and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) were used to measure capsaicin-induced autophagy via involvement of the class III PI3K/Beclin-1/Bcl-2 signaling pathway. Capsaicin induced autophagy by increasing levels of the autophagy markers LC3-II and Atg5, enhancing p62 and Fap-1 degradation and increasing caspase-3 activity to induce apoptosis, suggesting a correlation of blocking the PI3K/Akt/mTOR pathway with the above-mentioned anticancer activities. Taken together, these data confirm that capsaicin inhibited the growth of human NPC cells and induced autophagy, supporting its potential as a therapeutic agent for cancer

    Ethanolic Extracts of Pluchea indica Induce Apoptosis and Antiproliferation Effects in Human Nasopharyngeal Carcinoma Cells

    No full text
    Pluchea indica is used in traditional medicine for the treatment of lumbago, ulcer, tuberculosis and inflammation. The anti-cancer activities and the underlying molecular mechanisms of the ethanolic extracts of P. indica root (PIRE) were characterized in the present study. PIRE strongly inhibited the viability of the human nasopharyngeal carcinoma cells (NPC-TW 01 and NPC-TW 04) in a time- and dose-dependent manner. Migration of cancer cells was also suppressed by PIRE. In addition, PIRE significantly increased the occurrence of the cells in sub-G1 phase and the extent of DNA fragmentation in a dose-dependent manner, which indicates that PIRE significantly increased apoptosis in NPC cells. The apoptotic process triggered by PIRE involved up-regulation of pro-apoptotic Bax protein and down-regulation of anti-apoptotic Bcl-2 protein, consequently increasing the ratios of Bax/Bcl-2 protein levels. Moreover, the p53 protein was up-regulated by PIRE in a concentration-dependent manner. Therefore, PIRE could induce the apoptosis-signaling pathway in NPC cells by activation of p53 and by regulation of apoptosis-related proteins

    Palladium-Catalyzed Annulation of 2,2′-Diiodobiphenyls with Alkynes: Synthesis and Applications of Phenanthrenes

    No full text
    A range of phenanthrene derivatives were efficiently synthesized by the palladium-catalyzed annulation of 2,2′-diiodobiphenyls with alkynes. The scope, limitations and regioselectivity of the reaction were investigated. The described method was adopted to synthesize 9,10-dialkylphenanthrenes, sterically overcrowded 4,5-disubstituted phenanthrenes and phenanthrene-based alkaloids. Reactions of highly methoxy-substituted biphenyls with 2-(2-propynyl)­pyrrolidine and 2-(2-propynyl)­piperidine gave 2-(9-phenanthylmethyl)­pyrrolidines and 2-(9-phenanthylmethyl)­piperidines, respectively. The products were transformed to phenanthroindolizidine and phenanthroquinolizidine alkaloids by the Pictet–Spengler reaction

    Brefeldin A Reduces Anchorage-Independent Survival, Cancer Stem Cell Potential and Migration of MDA-MB-231 Human Breast Cancer Cells

    No full text
    Cancer stem cells (CSCs) are a subset of cancer cells in tumors or established cancer cell lines that can initiate and sustain the growth of tumors in vivo. Cancer stem cells can be enriched in serum-free, suspended cultures that allow the formation of tumorspheres over several days to weeks. Brefeldin A (BFA) is a mycotoxin that induces endoplasmic reticulum (ER) stress in eukaryotic cells. We found that BFA, at sub-microgram per milliliter concentrations, preferentially induced cell death in MDA-MB-231 suspension cultures (EC50: 0.016 µg/mL) compared to adhesion cultures. BFA also effectively inhibited clonogenic activity and the migration and matrix metalloproteinases-9 (MMP-9) activity of MDA-MB-231 cells. Western blotting analysis indicated that the effects of BFA may be mediated by the down-regulation of breast CSC marker CD44 and anti-apoptotic proteins Bcl-2 and Mcl-1, as well as the reversal of epithelial-mesenchymal transition. Furthermore, BFA also displayed selective cytotoxicity toward suspended MDA-MB-468 cells, and suppressed tumorsphere formation in T47D and MDA-MB-453 cells, suggesting that BFA may be effective against breast cancer cells of various phenotypes
    corecore