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Chou SC, Krishna V, Chou CH. Hydrophobic metabolites from Rhododendron formosanum and their allelopathic activities. Nat Prod Commun 2009; 4:1189-1192. [PMID: 19831026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Eighteen components were isolated from the methanolic extract of leaves of Rhododendron formosanum Hemsl. (Ericaceae), an endemic species in Taiwan, and evaluated for their allelopathic properties. Of the isolated compounds, 3beta-friedelinol, 5,6beta-epoxy-5beta-stigmastan-3beta-ol, 5,6alpha-epoxy-5alpha-stigmastan-3beta-ol, lupeol and ursolic acid revealed inhibitory effects at 10(-4) M or above, whereas alpha-tocopherol, friedelin and beta-amyrin acetate exhibited stimulatory effects on the radicle growth of the test plants at the same concentration or above. However, squalene and alpha-amyrin showed either a stimulatory or inhibitory effect. The remaining four components, coumarin, beta-sitosterol, adian-5-en-3beta-ol and 3beta-acetoxyurs-12-en-28-al, were not significantly effective in the present bioassay, but have been reported as allelopathic agents elsewhere.
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Chou SC, Krishna V, Chou CH. Hydrophobic Metabolites from Rhododendron formosanum and their Allelopathic Activities. Nat Prod Commun 2009. [DOI: 10.1177/1934578x0900400906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Eighteen components were isolated from the methanolic extract of leaves of Rhododendron formosanum Hemsl. (Ericaceae), an endemic species in Taiwan, and evaluated for their allelopathic properties. Of the isolated compounds, 3 β-friedelinol, 5,6β-epoxy-5β-stigmastan-3β-ol, 5,6α-epoxy-5α-stigmastan-3 β-ol, lupeol and ursolic acid revealed inhibitory effects at 10−4 M or above, whereas α-tocopherol, friedelin and β-amyrin acetate exhibited stimulatory effects on the radicle growth of the test plants at the same concentration or above. However, squalene and α-amyrin showed either a stimulatory or inhibitory effect. The remaining four components, coumarin, β-sitosterol, adian-5-en-3β-ol and 3β-acetoxyurs-12-en-28-al, were not significantly effective in the present bioassay, but have been reported as allelopathic agents elsewhere.
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Kuo WC, Chan CH, Chou CH, Cheng JCH. Swept source optical coherence tomography for radiation-enhanced hepatocellular carcinoma cell invasion imaging. Phys Med Biol 2009; 54:4289-97. [DOI: 10.1088/0031-9155/54/13/021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chang CI, Tsai FJ, Chou CH. Natural Products from Polygonum perfoliatum and their Diverse Biological Activities. Nat Prod Commun 2008. [DOI: 10.1177/1934578x0800300902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Nine components were isolated from the methanol extract of the whole herb of Polygonum perfoliatum and evaluated for their antioxidant activity. Among them, α-tocopherol and methyl trans-ferulate showed significant DPPH free radical scavenging effects with EC50 values of 11.9 and 7.8 μg/mL, respectively. In addition, five phenolic acids, caffeic acid, p-coumaric acid, p-hydroxybenzoic acid, protocatechuic acid, and vanillic acid were isolated from the aqueous extracts of the plant and identified by means of paper and high performance liquid chromatography. These five compounds were confirmed to be allelopathic substances by bioassay against the radicle growth of lettuce ( Lactuca sativa), Chinese cabbage ( Brassica oleracea), and radish ( Raphanus acanthiformis).
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Cheng HL, Huang HK, Chang CI, Tsai CP, Chou CH. A cell-based screening identifies compounds from the stem of Momordica charantia that overcome insulin resistance and activate AMP-activated protein kinase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:6835-6843. [PMID: 18656931 DOI: 10.1021/jf800801k] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Treatment of insulin resistance is a critical strategy in the prevention and management of type 2 diabetes. The crude extracts from all parts of Momordica charantia L. have been reported by many studies for the effective treatment of diabetes and related complications. However, the exact ingredients responsible for the hypoglycemic effect and the underlying mechanism of their actions have not been well characterized because of the lack of a proper assay and screening system. A new cell-based, nonradioactive, and nonfluorescent screening method was demonstrated in this study to screen for natural products from the stem of M. charantia, aiming to identify hypoglycemic components that can overcome cellular insulin resistance. The results suggest triterpenoids being potential hypoglycemic components of the plant and the mechanism underlying their action involving AMP-activated protein kinase.
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Chang CI, Chen CR, Liao YW, Cheng HL, Chen YC, Chou CH. Cucurbitane-type triterpenoids from the stems of momordica charantia. JOURNAL OF NATURAL PRODUCTS 2008; 71:1327-30. [PMID: 18637688 DOI: 10.1021/np070532u] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Four new cucurbitane-type triterpenes, cucurbita-5,23(E)-diene-3beta,7beta,25-triol (1), 3beta-acetoxy-7beta-methoxycucurbita-5,23(E)-dien-25-ol (2), cucurbita-5(10),6,23(E)-triene-3beta,25-diol (5), and cucurbita-5,24-diene-3,7,23-trione (6), together with four known triterpenes, 3beta,25-dihydroxy-7beta-methoxycucurbita-5,23(E)-diene (3), 3beta-hydroxy-7beta,25-dimethoxycucurbita-5,23(E)-diene (4), 3beta,7beta,25-trihydroxycucurbita-5,23(E)-dien-19-al (7), and 25-methoxy-3beta,7beta-dihydroxycucurbita-5,23(E)-dien-19-al (8), were isolated from the methyl alcohol extract of the stems of Momordica charantia. The structures of the new compounds were elucidated by spectroscopic methods.
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Lai IL, Schroeder WH, Wu JT, Kuo-Huang LL, Mohl C, Chou CH. Can fog contribute to the nutrition of Chamaecyparis obtusa var. formosana? Uptake of a fog solute tracer into foliage and transport to roots. TREE PHYSIOLOGY 2007; 27:1001-9. [PMID: 17403653 DOI: 10.1093/treephys/27.7.1001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Yellow cypress (Chamaecyparis obtusa (Siebold & Zucc.) Endl. var. formosana (Hayata) Rehder) is the predominant tree species of Taiwan's nutrient-poor, mountain fog forests. Little is known about the potential contribution of solute uptake from fog to the overall nutrition of these trees. Shoots of yellow cypress seedlings were misted with artificial fog containing the tracer rubidium (Rb) in laboratory and field experiments to determine if there is solute uptake from the fog. After misting shoots for six weeks, substantial amounts of tracer were detected in unexposed roots by inductively coupled plasma mass spectroscopy bulk analysis. Possible routes of entry were examined by element imaging with energy dispersive X-ray analysis. Direct uptake of the tracer into leaves across the cuticle and epidermis was small, excluding this as the major uptake path. Accumulations of Rb were found on leaf surfaces along the edges of the leaves. The almost daily changes in fog coverage and air humidity may enhance the accumulation of fog solutes at leaf edges. Accumulation of Rb was also found in narrow clefts between opposite leaves and between the outermost and underlying alternating stacked leaves. The clefts provide a direct passage from the leaf surface to the space beneath the imbricate leaves and the underlying alternate leaves, possibly facilitating solute uptake from fog, which in turn may contribute to the nutrition of yellow cypress.
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Shen YC, Lin YS, Hsu SM, Khalil A, Wang SS, Chien CT, Kuo YH, Chou CH. Tasumatrols P – T, Five New Taxoids fromTaxus sumatrana. Helv Chim Acta 2007. [DOI: 10.1002/hlca.200790133] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Liu CH, Yeh SP, Kuo CM, Cheng W, Chou CH. The effect of sodium alginate on the immune response of tiger shrimp via dietary administration: activity and gene transcription. FISH & SHELLFISH IMMUNOLOGY 2006; 21:442-52. [PMID: 16684609 DOI: 10.1016/j.fsi.2006.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 02/01/2006] [Accepted: 02/13/2006] [Indexed: 05/09/2023]
Abstract
The total haemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (release of superoxide anions), and superoxide dismutase (SOD) activity, as well as expressions of beta-1,3-glucan-binding protein (betaGBP), prophenoloxidase (proPO), peroxinectin (PE), cytosolic SOD (cyt-SOD), penaeidin-5 (PA-5), and a single whey acidic protein (WAP) domain protein (SWDP) gene were determined in the tiger shrimp Penaeus monodon (15.6-19.5g) which had individually been fed diets containing sodium alginate at 0, 1.0, or 2.0gkg(-1) for 5months. Results showed that shrimp fed a diet containing 1.0 and 2.0gkg(-1) sodium alginate had significantly increased SOD activity but decreased respiratory bursts. The expressions of betaGBP, PE, cyt-SOD, PA-5, and SWDP were significantly elevated in shrimp fed the
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Chang CI, Chen CR, Liao YW, Cheng HL, Chen YC, Chou CH. Cucurbitane-type triterpenoids from Momordica charantia. JOURNAL OF NATURAL PRODUCTS 2006; 69:1168-71. [PMID: 16933869 DOI: 10.1021/np068008v] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Five new cucurbitane-type triterpenes, (23E)-25-methoxycucurbit-23-ene-3beta,7beta-diol (1), (23E)-cucurbita-5,23,25-triene-3beta,7beta-diol (2), (23E)-25-hydroxycucurbita-5,23-diene-3,7-dione (3), (23E)-cucurbita-5,23,25-triene-3,7-dione (4), and (23E)-5beta,19-epoxycucurbita-6,23-diene-3beta,25-diol (5), together with one known triterpene, (23E)-5beta,19-epoxy-25-methoxycucurbita-6,23-dien-3beta-ol (6), have been isolated from the methanol extract of the stems of Momordica charantia. The structures of the new compounds were elucidated by spectroscopic methods.
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Krishna V, Chang CI, Chou CH. Two isomeric epoxysitosterols from Rhododendron formosanum: 1H and 13C NMR chemical shift assignments. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2006; 44:817-9. [PMID: 16724364 DOI: 10.1002/mrc.1844] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
1H and 13C NMR assignments of the two isomeric epoxysitosterols, 5,6 alpha-epoxy-5 alpha-stigmastan-3 beta-ol (1) and 5,6 beta-epoxy-5 beta-stigmastan-3 beta-ol (2), isolated from the leaves of Rhododendron formosanum Hemsl were achieved by 1D and 2D techniques such as DEPT, HMBC, HMQC, COSY and NOESY.
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Cheng JCH, Chou CH, Kuo ML, Hsieh CY. Radiation-enhanced hepatocellular carcinoma cell invasion with MMP-9 expression through PI3K/Akt/NF-kappaB signal transduction pathway. Oncogene 2006; 25:7009-18. [PMID: 16732316 DOI: 10.1038/sj.onc.1209706] [Citation(s) in RCA: 259] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This study is to investigate the molecular mechanism of radiation-enhanced cell invasiveness of hepatocellular carcinoma (HCC) correlating with clinical patients undergoing radiotherapy and subsequently developing metastasis. Three HCC cell lines (HepG2, Hep3B and Huh7) and normal hepatocyte cell line (CL-48) were irradiated with different doses. The effect of radiation on cell invasiveness was determined using the Boyden chamber assay. Radiation-enhanced invasion capability was evident in HCC cells but not in normal hepatocytes. Invasion was observed in gelatin-coated but not fibronectin-coated or type I collagen-coated membranes. Radiation upregulated matrix metalloproteinase-9 (MMP-9) mRNA level, MMP-9 protein level and MMP-9 activity. MMP-9 antisense oligonucleotides inhibited radiation-induced MMP-9 expression and thereby significantly inhibited radiation-induced HCC invasion. Furthermore, phosphatidylinositol 3-kinase (PI3K)/Akt chemical inhibitors LY294002 and wortmannin suppressed radiation-induced MMP-9 mRNA expression. Transient transfection with dominant-negative Akt plasmid also showed that the PI3K/Akt-signaling pathway was involved in this radiation-induced MMP-9 expression. Moreover, nuclear factor-kappaB (NF-kappaB) decoy oligodeoxynucleotide suppressed radiation enhanced MMP-9 promoter activity completely. PI3K/Akt chemical inhibitors inhibited radiation-induced NF-kappaB-driven luciferase promoter activity. Taken together, our results indicated that sublethal dose of radiation could enhance HCC cell invasiveness by MMP-9 expression through the PI3K/Akt/NF-kappaB signal transduction pathway.
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Lay JJ, Tsai CJ, Huang CC, Chang JJ, Chou CH, Fan KS, Chang JI, Hsu PC. Influences of pH and hydraulic retention time on anaerobes converting beer processing wastes into hydrogen. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 52:123-9. [PMID: 16180418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
To convert high-solids organic wastes (3% w./w.) to high-value hydrogen, a full factorial experimental design was employed in planning the experiments for learning the effects of pH and hydraulic retention time (HRT) on the hydrogen production in a chemostat reactor using waste yeast obtained from beer processing wastes. For determining which experimental variable settings affect hydrogen production, predictive polynomial quadratic equation and response surface methodology were employed to determine and explain the conditions required for high-value hydrogen production. Experimental results indicate that a maximum hydrogen production rate of 460 mL/gVSS/d was obtained at pH = 5.8 and HRT = 32 hours. Moreover, hydrogenase targeted RT-PCR results indicate that Clostridium thermocellum and Klebsiella pneumoniae predominated.
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Shen YC, Hsu SM, Lin YS, Cheng KC, Chien CT, Chou CH, Cheng YB. New Bicyclic Taxane Diterpenoids from Taxus sumatrana. Chem Pharm Bull (Tokyo) 2005; 53:808-10. [PMID: 15997140 DOI: 10.1248/cpb.53.808] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Investigation of an acetone extract of the leaves and twigs of Taxus sumatrana has resulted in the isolation of two new bicyclic taxoids, tasumatrols M (1), and N (2) and a new baccatin III derivative, tasumatrol O (3) together with the previous known 7-deacetylcanadensene (4) and 2alpha,7beta,13alpha-triacetoxy-5alpha,9alpha-dihydroxy-2(3-->20) abeotaxa-4(20),11-dien-10-one. The structures of these taxanes were established on the basis of spectroscopic analyses, especially 1- and 2D NMR, and chemical derivatization.
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Abstract
Three humic substances--humic acid, fulvic acid, and humin--were isolated from soils located in the northern and southern forests of the Yuanyang Lake Nature Preserve in northern Taiwan's Ilan County. Aqueous extracts of fresh wet soil and of three humic substances, at concentrations of 0.125, 0.25, and 0.5 mg/ml, were investigated for their effects on the activities of chlorophyllase a and b. Aqueous extracts of forest soils at the northern and southern bank, dominated by the pure vegetation of Formosan False cypress (Chamcaecyparis formosensis Matsum), stimulate both chlorophyllase a and b activities, while those of the southern bank, dominated by a Taiwanese Miscanthus (Miscanthus transmorrisonensis Hayata), inhibits such activities. All three humic substances, despite their soil sources, stimulate the activities of both chlorophyllase a and b. Fulvic acid stimulates more chlorophyllase a activity than either humic acid or humin. Humic acid stimulates more activity of chlorophyllase b than either fulvic acid or humin. Humin exhibited the least effect on chlorophyllase a and b. It is suggested that humic substances in the soil may accelerate the chlorophyll degradation of litter in the ecosystem and that chlorophyllase a and b may be different enzymes.
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Chao AC, Chern CM, Kuo TB, Chou CH, Chuang YM, Wong WJ, Hu HH. Noninvasive assessment of spontaneous baroreflex sensitivity and heart rate variability in patients with carotid stenosis. Cerebrovasc Dis 2003; 16:151-7. [PMID: 12792173 DOI: 10.1159/000070595] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2002] [Accepted: 10/09/2002] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Previous limited observations have suggested that atherosclerosis may affect the distensibility of the carotid sinus and then impair the baroreflex sensitivity (BRS). No studies have been done to compare the BRS and heart rate variability (HRV) in patients with carotid stenosis and normal controls. METHODS A convenience-consecutive sample of 118 patients with transient ischemic attack or minor stroke 3 months to 1 year before (mean 6 months) who met the study criteria were referred to the neurovascular laboratory of the study hospital. Forty-three age-matched healthy adults were recruited as the normal controls. The inclusion criteria for participation were (1) no diabetes mellitus, (2) no history, symptoms or ECG signs of coronary artery disease or myocardial infarction, and (3) presence of carotid stenosis greater than or equal to 50%. The diagnosis of carotid stenosis was made using color-coded duplex ultrasound with published criteria. We categorized the patients into two groups: group 1 had moderate stenosis (50-75%) and group 2 had high-grade stenosis (75-99%). Instantaneous systolic blood pressure (SBP) and heart rate of all participants were assessed noninvasively using servo-controlled infrared finger plethysmography. The fluctuation in SBP as well as the interpulse interval (IPI) was divided into three components at specific frequency ranges by fast Fourier transform as high frequency (HF; 0.15-0.4 Hz), low frequency (LF; 0.04-0.15 Hz) and very low frequency (VLF; 0.004-0.04 Hz). The BRS was expressed as (1) transfer function with its magnitude in the HF and LF ranges, (2) BRS index alpha, and (3) regression coefficient by sequence analysis. The HRV was expressed as total power and power in the three frequency ranges (HF, LF and VLF). RESULTS The final analysis included 99 patients (mean age 72 +/- 6 years, 79 male) and 43 healthy controls (mean age 68 +/- 7 years, 30 male). Forty-three patients were classified as group 1 (stenosis 50-75%) and 56 as group 2 (stenosis 75-99%). There was no significant difference in the IPI between patients and controls (p value = 0.8637). We observed a significant decrease in all three HRV components (VLF, LF and HF) in the patients; however, there were no differences between the two patient groups with various degrees of stenosis. All the indices of BRS, including the magnitude of SBP-IPI transfer function at LF and HF, the computed BRS index alpha and the regression coefficient of sequence analysis, revealed similar results. Patients exhibited a significant reduction in the BRS (p < 0.001) compared with controls, and no difference was found between the two groups of patients. CONCLUSIONS Our study linked significant carotid stenosis to two important autonomic markers (BRS and HRV) that may have prognostic value for patients with cardiovascular events. Further prospective studies are needed to explore whether or not the decreased BRS and HRV can be predictors for poor cardiovascular prognosis, or even for shortened life span in general, in patients with significant carotid stenosis.
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Tseng MH, Kuo YH, Chen YM, Chou CH. Allelopathic potential of Macaranga tanarius (L.) muell.-arg. J Chem Ecol 2003; 29:1269-86. [PMID: 12857035 DOI: 10.1023/a:1023846010108] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Macaranga tanarius is widely distributed in the abandoned lowlands of Taiwan where substantial amounts of leaves accumulate on the ground. A unique pattern of weed exclusion underneath trees is often found and thought to result from allelopathic interactions. Density-dependent phytotoxicity analysis of Lactuca sativa L. (lettuce) growing in soil mixed with the powder of M. tanarius leaves showed a significant deviation from the expected yield-density relationship. Lettuce growth was most suppressed in the low seed density experiment suggesting that the phytotoxins produced during leaf decomposition inhibit the growth of lettuce seedlings. Bidens pilosa and Leucaena leucocephala, growing in soil mixed with the leaf powder of M. tanarius were also suppressed. Aqueous leaf extracts were bioassayed against lettuce and B. pilosa, and exhibited a significant suppression in radicle growth. Compounds identified from leaves included nymphaeol-A (1), nymphaeol-B (2), nymphaeol-C (3), quercetin (4), abscisic acid (ABA) (5), blumenol A (6), blumenol B (7), roseoside II (8), tanariflavanone A (9), and tanariflavanone B (10), ABA was the major growth inhibitor. At concentrations of 20 ppm, ABA suppressed lettuce germination, while at 120 ppm it inhibited the growth of Miscanthus floridulus, Chloris barbata, and Bidens pilosa. At 600 ppm, quercetin, blumenol A, and blumenol B, caused 20-25% inhibition of radicle and shoot growth of M. floridulus. The amount of ABA in M. tanarius leaves was approximately 3-5 microg g(-1) dry weight, significantly higher than previously reported. We conclude that the pattern of weed exclusion underneath stands of M. tanarius and its invasion into its adjacent grassland vegetation results from allelopathic interactions.
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Chiang YC, Schaal BA, Chou CH, Huang S, Chiang TY. Contrasting selection modes at the Adh1 locus in outcrossing Miscanthus sinensis vs. inbreeding Miscanthus condensatus (Poaceae). AMERICAN JOURNAL OF BOTANY 2003; 90:561-570. [PMID: 21659149 DOI: 10.3732/ajb.90.4.561] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We estimated DNA sequence variation of the Adh1 locus in the outcrossing Miscanthus sinensis (Poaceae) and its close selfing relative, M. condensatus. Tajima's test of selection is significantly negative for both overall exons and replacement sites in M. sinensis. Among its entire sample, nucleotide diversity of nonsynonymous sites is higher than that of synonymous sites. A McDonald and Kreitman test of neutrality indicates an excess of intraspecific replacement polymorphisms, suggesting possible directional selection toward advantageous mutants. However, frequent intragenic recombination suggests both purifying and positive selection is unlikely. Recent demographic expansions coupled with relaxation of purifying selection may have resulted in elevated genetic diversity at the Adh1 locus as well as the trnL-trnF intergenic spacer of cpDNA in this outcrossing species. In contrast, low levels of genetic diversity were detected at both the Adh1 locus and the cpDNA spacer in M. condensatus, consistent with bottlenecks associated with selfing in all populations. While Tajima's D and Fu and Li's F statistics did not reveal deviation from neutrality at the Adh1 locus in M. condensatus, 12 replacements vs. 10 synonymous changes were detected. Based on pairwise comparisons of the d(N)/d(S) ratio, lineages of closely related populations of the species distributed along saline habitats appeared to be under directional selection.
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Chou CH, Chau T, Yang SS, Lin SH. Acute hyponatremia and renal failure following percutaneous nephrolithotomy. Clin Nephrol 2003; 59:237-8. [PMID: 12653273 DOI: 10.5414/cnp59237] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Chiang YC, Ge XJ, Chou CH, Wu WL, Chiang TY. Nucleotide sequence diversity at the methionine synthase locus in endangered Dunnia sinensis (Rubiaceae): an evaluation of the positive selection hypothesis. Mol Biol Evol 2002; 19:1367-75. [PMID: 12140249 DOI: 10.1093/oxfordjournals.molbev.a004198] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Methionine synthase is a key enzyme for the synthesis of the aspartate-derived methionine, the immediate precursor of S-adenosyl-methionine, which has been illustrated to be associated with plant growth and pathogen interactions. In this study we tested the positive selection hypothesis of molecular evolution of the methionine synthase gene in Dunnia sinensis. In the entire sample of 87 sequences, 22 haplotypes of introns and 16 haplotypes of exons were identified. An excess of polymorphism over the neutral expectation for the class of unique nucleotide polymorphisms was observed in both exon and intron sequences. Ten replacement substitutions versus six synonymous substitutions among lineages, although nonsignificant, revealed that some advantageous mutants might have been favored. The distribution of d(N)/d(S) > 1 at nodes between closely related haplotypes in the gene network also indicated weak and variable positive selection. Nevertheless, low levels of genetic diversity in exons (theta; = 0.0052) and introns (theta; = 0.0070) of the methionine synthase gene of the outcrossing Dunnia were also attributed to the endangered status of the species. The atpB-rbcL intergenic spacer of cpDNA and the ribosomal internal transcribed spacer of mtDNA were used to discern the relative effectiveness of natural selection from intrinsic evolutionary forces. The low levels of nucleotide polymorphisms in both organelle spacers and the significant population differentiation reflected the effect of population-species history and demography. Two major lineages of the methionine synthase gene genealogy were recovered corresponding to two geographic regions, a result that was consistent with organelle phylogenies. Both past fragmentation and recent habitat disturbance causing complete bottlenecks may have resulted in population decline and geographic isolation and may have led to the depletion of genetic variation at loci in nuclear and organelle genomes.
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Lee TH, Wang GJ, Lee CK, Kuo YH, Chou CH. Inhibitory effects of glycosides from the leaves of Melaleuca quinquenervia on vascular contraction of rats. PLANTA MEDICA 2002; 68:492-496. [PMID: 12094289 DOI: 10.1055/s-2002-32563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two new glycosides, 3-hydroxy-5-methoxy-4-methylphenyl beta-D-glucopyranoside (1) and 4-benzoyl-2-C-beta-glucopyranosyl-3,5-dihydroxy-6-methylphenyl beta-D-glucopyranoside (2), together with four known glycosides, 2-endo-beta-D-glucopyranosyloxy-1,8-cineole (3a), 2-exo-beta-D-glucopyranosyloxy-1,8-cineole (3b), roseoside (4), and citroside A (5), were isolated from the methanolic extract of leaves of Melaleuca quinquenervia. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1, 2a and 3 inhibited contractile response induced by phenylephrine in aortic rings from Sprague-Dawley rats. This inhibition was independent of the endothelium. Compounds 2 and 4 significantly relaxed precontracted aortic rings, in an endothelium-dependent manner. Pretreatment of N(omega)-nitro-L-arginine (L-NNA), a nitric oxide synthase inhibitor, partially attenuated the vasorelaxation induced by both compounds, suggesting that nitric oxide was likely the responsible mediator. The rank-order potency (EC 50 value) of vasorelaxing activities of these compounds is 4 > 2 > 2a > 3 > 1.
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Chou CH, Lee TS. Peripheral tears of triangular fibrocartilage complex: results of primary repair. INTERNATIONAL ORTHOPAEDICS 2001; 25:392-5. [PMID: 11820450 PMCID: PMC3620789 DOI: 10.1007/s002640100285] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In 16 patients with ulnar wrist pain, we performed primary arthroscopic or open repair of the peripheral rim tears of the triangular fibrocartilage complex (TFCC) (14 ulnar, 4 volar, and 3 radial tears). The wrist function was assessed before and 1 year after the repair using the Mayo-modified wrist score. The average pain score improved from 9.1+/-8.0 to 21.2+/-6.5, the average functional score from 5.0+/-8.1 to 20.6+/-6.3, the average motion score from 4.7+/-2.8 to 15.6+/-7.3, and the average grip point from 4.4+/-3.5 to 15.6+/-7.7, all with significant differences (P<0.01). Ten of the 17 cases had instability of the distal radioulnar joint and five had recurrent instability after repair.
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Chiang TY, Chiang YC, Chen YJ, Chou CH, Havanond S, Hong TN, Huang S. Phylogeography of Kandelia candel in East Asiatic mangroves based on nucleotide variation of chloroplast and mitochondrial DNAs. Mol Ecol 2001; 10:2697-710. [PMID: 11883883 DOI: 10.1046/j.0962-1083.2001.01399.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vivipary with precocious seedlings in mangrove plants was thought to be a hindrance to long-range dispersal. To examine the extent of seedling dispersal across oceans, we investigated the phylogeny and genetic structure among East Asiatic populations of Kandelia candel based on organelle DNAs. In total, three, 28 and seven haplotypes of the chloroplast DNA (cpDNA) atpB-rbcL spacer, cpDNA trnL-trnF spacer, and mitochondrial DNA (mtDNA) internal transcribed spacer (ITS) were identified, respectively, from 202 individuals. Three data sets suggested consistent phylogenies recovering two differentiated lineages corresponding to geographical regions, i.e. northern South-China-Sea + East-China-Sea region and southern South-China-Sea region (Sarawak). Phylogenetically, the Sarawak population was closely related to the Ranong population of western Peninsula Malaysia instead of other South-China-Sea populations, indicating its possible origin from the Indian Ocean Rim. No geographical subdivision was detected within the northern geographical region. An analysis of molecular variance (AMOVA) revealed low levels of genetic differentiation between and within mainland and island populations (phiCT = 0.015, phiSC = 0.037), indicating conspicuous long-distance seedling dispersal across oceans. Significant linkage disequilibrium excluded the possibility of recurrent homoplasious mutations as the major force causing phylogenetic discrepancy between mtDNA and the trnL-trnF spacer within the northern region. Instead, relative ages of alleles contributed to non-random chlorotype-mitotype associations and tree inconsistency. Widespread distribution and random associations (chi2 = 0.822, P = 0.189) of eight hypothetical ancestral cytotypes indicated the panmixis of populations of the northern geographical region as a whole. In contrast, rare and recently evolved alleles were restricted to marginal populations, revealing some preferential directional migration.
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Huang S, Chiang YC, Schaal BA, Chou CH, Chiang TY. Organelle DNA phylogeography of Cycas taitungensis, a relict species in Taiwan. Mol Ecol 2001; 10:2669-81. [PMID: 11883881 DOI: 10.1046/j.0962-1083.2001.01395.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The phylogegraphic pattern of Cycas taitungensis, an endemic species with two remaining populations in Taiwan, was investigated based on genetic variability and phylogeny of the atpB-rbcL noncoding spacer of chloroplast DNA (cpDNA) and the ribosomal DNA (rDNA) internal transcribed spacer (ITS) of mitochondrial DNA (mtDNA). High levels of genetic variation at both organelle loci, due to frequent intramolecular recombination, and low levels of genetic differentiation were detected in the relict gymnosperm. The apportionment of genetic variation within and between populations agreed with a migrant-pool model, which describes a migratory pattern with colonists recruited from a random sample of earlier existing populations. Phylogenies obtained from cpDNA and mtDNA were discordant according to neighbour-joining analyses. In total four chlorotypes (clades I-IV) and five mitotypes (clades A-E) were identified based on minimum spanning networks of each locus. Significant linkage disequilibrium in mitotype-chlorotype associations excluded the possibility of the recurrent homoplasious mutations as the major force causing phylogenetic inconsistency. The most abundant chlorotype I was associated with all mitotypes and the most abundant mitotype C with all chlorotypes; no combinations of rare mitotypes with rare chlorotypes were found. According to nested clade analyses, such nonrandom associations may be ascribed to relative ages among alleles associated with the geological history through which cycads evolved. Nested in networks as interior nodes coupled with wide geographical distribution, the most dominant cytotypes of CI and EI may represent ancestral haplotypes of C. taitungensis with a possible long existence prior to the Pleistocene glacial maximum. In contrast, rare chlorotypes and mitotypes with restricted and patchy distribution may have relatively recent origins. Newly evolved genetic elements of mtDNA, with a low frequency, were likely to be associated with the dominant chlorotype, and vice versa, resulting in the nonrandom mitotype-chlorotype associations. Paraphyly of CI and EI cytotypes, leading to the low level of genetic differentiation between cycad populations, indicated a short period for isolation, which allowed low possibilities of the attainment of coalescence at polymorphic ancestral alleles.
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Cheng CL, Chou CH. Determination of metformin in human plasma by high-performance liquid chromatography with spectrophotometric detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 762:51-8. [PMID: 11589458 DOI: 10.1016/s0378-4347(01)00342-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A simple, selective, sensitive and precise high-performance liquid chromatographic plasma assay for the hypoglycemic agent metformin is described. Acidified samples of plasma were deproteinated with acetonitrile, washed with dichloromethane and the resulting supernatant injected. Chromatography was performed at 40 degrees C by pumping a mobile phase of acetonitrile (250 ml) in pH 7, 0.03 M diammonium hydrogen phosphate buffer (750 ml) at a flow-rate of 1 ml/min through a silica column. Metformin and the internal standard (atenolol) were detected at 240 nm and were eluted 7.8 and 6.8 min, respectively, after injection. No endogenous substances were found to interfere. Calibration curves were linear (r>0.999) from 10 to 2000 ng/ml. The absolute recovery of both metformin and atenolol was greater than 76%. The detection limit and limit of quantitation were 2.5 and 10 ng/ml, respectively. The intra- and inter-day precision (C.V.) was 12%, or less, and the accuracy was within 6.2% of the nominal concentration. This method is suitable for clinical investigation and monitoring metformin concentration.
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