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121.
Our previous studies have identified berberine (BBR), an alkaloid isolated from the Chinese herb huanglian, as a unique cholesterol-lowering drug that upregulates hepatic low density lipoprotein receptor (LDLR) expression through a mechanism of mRNA stabilization. Here, we demonstrate that the root extract of goldenseal, a BBR-containing medicinal plant, is highly effective in upregulation of liver LDLR expression in HepG2 cells and in reducing plasma cholesterol and low density lipoprotein cholesterol (LDL-c) in hyperlipidemic hamsters, with greater activities than the pure compound BBR. By conducting bioassay-driven semipurifications, we demonstrate that the higher potency of goldenseal is achieved through concerted actions of multiple bioactive compounds in addition to BBR. We identify canadine (CND) and two other constituents of goldenseal as new upregulators of LDLR expression. We further show that the activity of BBR on LDLR expression is attenuated by multiple drug resistance-1 (MDR1)-mediated efflux from liver cells, whereas CND is resistant to MDR1. This finding defines a molecular mechanism for the higher activity of CND than BBR. We also provide substantial evidence to show that goldenseal contains natural MDR1 antagonist(s) that accentuate the upregulatory effect of BBR on LDLR mRNA expression. These new findings identify goldenseal as a natural LDL-c-lowering agent, and our studies provide a molecular basis for the mechanisms of action. 相似文献
122.
Jocelyn Chan Heather F. Gidding Christopher C. Blyth Parveen Fathima Sanjay Jayasinghe Peter B. McIntyre Hannah C. Moore Kim Mulholland Cattram D. Nguyen Ross Andrews Fiona M. Russell 《PLoS medicine》2021,18(8)
BackgroundThere is limited empiric evidence on the coverage of pneumococcal conjugate vaccines (PCVs) required to generate substantial indirect protection. We investigate the association between population PCV coverage and indirect protection against invasive pneumococcal disease (IPD) and pneumonia hospitalisations among undervaccinated Australian children.Methods and findingsBirth and vaccination records, IPD notifications, and hospitalisations were individually linked for children aged <5 years, born between 2001 and 2012 in 2 Australian states (New South Wales and Western Australia; 1.37 million children). Using Poisson regression models, we examined the association between PCV coverage, in small geographical units, and the incidence of (1) 7-valent PCV (PCV7)-type IPD; (2) all-cause pneumonia; and (3) pneumococcal and lobar pneumonia hospitalisation in undervaccinated children. Undervaccinated children received <2 doses of PCV at <12 months of age and no doses at ≥12 months of age. Potential confounding variables were selected for adjustment a priori with the assistance of a directed acyclic graph.There were strong inverse associations between PCV coverage and the incidence of PCV7-type IPD (adjusted incidence rate ratio [aIRR] 0.967, 95% confidence interval [CI] 0.958 to 0.975, p-value < 0.001), and pneumonia hospitalisations (all-cause pneumonia: aIRR 0.991 95% CI 0.990 to 0.994, p-value < 0.001) among undervaccinated children. Subgroup analyses for children <4 months old, urban, rural, and Indigenous populations showed similar trends, although effects were smaller for rural and Indigenous populations. Approximately 50% coverage of PCV7 among children <5 years of age was estimated to prevent up to 72.5% (95% CI 51.6 to 84.4) of PCV7-type IPD among undervaccinated children, while 90% coverage was estimated to prevent 95.2% (95% CI 89.4 to 97.8). The main limitations of this study include the potential for differential loss to follow-up, geographical misclassification of children (based on residential address at birth only), and unmeasured confounders.ConclusionsIn this study, we observed substantial indirect protection at lower levels of PCV coverage than previously described—challenging assumptions that high levels of PCV coverage (i.e., greater than 90%) are required. Understanding the association between PCV coverage and indirect protection is a priority since the control of vaccine-type pneumococcal disease is a prerequisite for reducing the number of PCV doses (from 3 to 2). Reduced dose schedules have the potential to substantially reduce program costs while maintaining vaccine impact.In an observational study, Jocelyn Chan and colleagues investigate associations between pneumococcal conjugate vaccine coverage and incidence of invasive pneumococcal disease and pneumonia among children under 5 years in Australia. 相似文献
123.
Md. Zahangir Alam Parveen Jamal Masrina M. Nadzir 《World journal of microbiology & biotechnology》2008,24(7):1177-1185
A laboratory-scale study was conducted to evaluate the feasibility of using palm oil mill effluent (POME) as a major substrate
and other nutrients for maximum production of citric acid using the potential fungal strain Aspergillus niger (A103). Statistical optimization of medium composition (substrate–POME, co-substrates–wheat flour and glucose, and nitrogen
source–ammonium nitrate) and fermentation time was carried out by central composite design (CCD) to develop a polynomial regression
model through the effects of linear, quadratic, and interaction of the factors. The statistical analysis of the results showed
that, in the range studied, ammonium nitrate had no significant effect whereas substrate, co-substrates and fermentation time
had significant effects on citric acid production. The optimized medium containing 2% (w/w) of substrate concentration (POME),
4% (w/w) of wheat flour concentration, 4% (w/w) of glucose concentration, 0% (w/v) of ammonium nitrate and 5 days fermentation
time gave the maximum predicted citric acid of 5.37 g/l which was found to be 1.5 g/l in the experimental run. The determination
of coefficient (R
2) from the analysis observed was 0.964, indicating a satisfactory adjustment of the model with the response. The analysis
showed that the major substrate POME (P < 0.05), glucose (P < 0.01), nutrient (P < 0.05), and fermentation time (P < 0.01) was more significant for citric acid production. The bioconversion of POME for citric acid production using optimal
conditions showed the higher removal of chemical oxygen demand (82%) with the production of citric acid (5.2 g/l) on the final
day of fermentation process (7 days). The pH and biosolids accumulation were observed during the bioconversion process. 相似文献
124.
Chhuneja P Kaur S Garg T Ghai M Kaur S Prashar M Bains NS Goel RK Keller B Dhaliwal HS Singh K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(3):313-324
Stripe rust, caused by Puccinia striiformis West. f.sp. tritici, is one of the most damaging diseases of wheat worldwide. Forty genes for stripe rust resistance have been catalogued so
far, but the majority of them are not effective against emerging pathotypes. Triticum monococcum and T. boeoticum have excellent levels of resistance to rusts, but so far, no stripe rust resistance gene has been identified or transferred
from these species. A set of 121 RILs generated from a cross involving T. monococcum (acc. pau14087) and T. boeoticum (acc. pau5088) was screened for 3 years against a mixture of pathotypes under field conditions. The parental accessions were
susceptible to all the prevalent pathotypes at the seedling stage, but resistant at the adult plant stage. Genetic analysis
of the RIL population revealed the presence of two genes for stripe rust resistance, with one gene each being contributed
by each of the parental lines. A linkage map with 169 SSR and RFLP loci generated from a set of 93 RILs was used for mapping
these resistance genes. Based on phenotypic data for 3 years and the pooled data, two QTLs, one each in T. monococcum acc. pau14087 and T. boeoticum acc. pau5088, were detected for resistance in the RIL population. The QTL in T. monococcum mapped on chromosome 2A in a 3.6 cM interval between Xwmc407 and Xwmc170, whereas the QTL from T. boeoticum mapped on 5A in 8.9 cM interval between Xbarc151 and Xcfd12 and these were designated as QYrtm.pau-2A and QYrtb.pau-5A, respectively. Based on field data for 3 years, their R
2 values were 14 and 24%, respectively. T. monococcum acc. pau14087 and three resistant RILs were crossed to hexaploid wheat cvs WL711 and PBW343, using T. durum as a bridging species with the objective of transferring these genes into hexaploid wheat. The B genome of T. durum suppressed resistance in the F1 plants, but with subsequent backcrossing one resistance gene could be transferred from one of the RILs to the hexaploid wheat
background. This gene was derived from T. boeoticum acc. pau5088 as indicated by co-introgression of T. boeoticum sequences linked to stripe rust resistance QTL, QYrtb.pau-5A. Homozygous resistant progenies with 40–42 chromosomes have been identified.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
125.
Iram Parveen Naseem Ahmed Danish Idrees Parvez Khan Md. Imtaiyaz Hassan 《Bioorganic & medicinal chemistry letters》2017,27(18):4493-4499
Substituted 2-amino-7-((6-(4-(2-hydroxyethyl) piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-4H-chromene-3-carbonitriles and 2-amino-7-((6-(4-(2-hydroxyethyl)piperazin-1-yl)-2-methylpyrimidin-4-yl)oxy)-4-phenyl-1,4-dihydroquinoline-3-carbonitriles were synthesized via an efficient multi-component one pot synthesis under mild conditions. These compounds 1–20 were evaluated against human breast cancer cell lines (MCF-7) and human embryonic kidney cells (HEK293) for cytotoxic activities. Among them, compounds 6, 7, 15, 17 and 19 showed better anti-proliferative activities as (IC50 value 48 ± 1.70, 65 ± 1.13, 92 ± 1.18, 30 ± 1.17 and 16 ± 1.10 µM) than curcumin drug (48 ± 1.11 µM). Molecular docking was also performed with active compounds 6, 7 and 15 against Bcl-2 protein which gave good binding affinity (ΔG = ?9.08, ?8.29 and ?7.70 kcal/mol) respectively. Furthermore, the structure-activity relationship (SAR) analysis revealed that the chromene and quinoline moieties, when attached with pyrimide and piperazine moieties, enhanced anti-proliferative activities. 相似文献
126.
Thierry Menguy Fabienne Corre Birte Juul Laurence Bouneau Daniel Lafitte Peter J Derrick Parveen S Sharma Pierre Falson Barry A Levine Jesper V M?ller Marc le Maire 《The Journal of biological chemistry》2002,277(15):13016-13028
We previously found that mutants of conserved aspartate residues of sarcoplasmic reticulum Ca(2+)-ATPase in the cytosolic loop, connecting transmembrane segments M6 and M7 (L6-7 loop), exhibit a strongly reduced sensitivity toward Ca(2+) activation of the transport process. In this study, yeast membranes, expressing wild type and mutant Ca(2+)-ATPases, were reacted with Cr small middle dotATP and tested for their ability to occlude (45)Ca(2+) by HPLC analysis, after cation resin and C(12)E(8) treatment. We found that the D813A/D818A mutant that displays markedly low calcium affinity was capable of occluding Ca(2+) to the same extent as wild type ATPase. Using NMR and mass spectrometry we have analyzed the conformational properties of the synthetic L6-7 loop and demonstrated the formation of specific 1:1 cation complexes of the peptide with calcium and lanthanum. All three aspartate Asp(813)/Asp(815)/Asp(818) were required to coordinate the trivalent lanthanide ion. Overall these observations suggest a dual function of the loop: in addition to mediating contact between the intramembranous Ca(2+)-binding sites and the cytosolic phosphorylation site (Zhang, Z., Lewis, D., Sumbilla, C., Inesi G., and Toyoshima, C. (2001) J. Biol. Chem. 276, 15232-15239), the L6-7 loop, in a preceding step, participates in the formation of an entrance port, before subsequent high affinity binding of Ca(2+) inside the membrane. 相似文献
127.
Du GG Avila G Sharma P Khanna VK Dirksen RT MacLennan DH 《The Journal of biological chemistry》2004,279(36):37566-37574
The role of the sequence surrounding M4 in ryanodine receptors (RyR) in membrane association and function was investigated. This sequence contains a basic, 19-amino acid M3/M4 loop, a hydrophobic 44-49 amino acid sequence designated M4 (or M4a/M4b), and a hydrophilic M4/M5 loop. Enhanced green fluorescent protein (EGFP) was inserted into RyR1 and truncated just after the basic sequence, just after M4, within the M4/M5 loop, just before M5 and just after M5. The A52 epitope was inserted into RyR2 and truncated just after M4a. Analysis of these constructs ruled out a M3/M4 transmembrane hairpin and narrowed the region of membrane association to M4a/M4b. EGFP inserted between M4a and M4b in full-length RyR2 was altered conformationally, losing fluorescence and gaining trypsin sensitivity. Although it was accessible to an antibody from the cytosolic side, tryptic fragments were membrane-bound. The expressed protein containing EGFP retained caffeine-induced Ca(2+) release channel function. These results suggest that M4a/M4b either forms a transmembrane hairpin or associates in an unorthodox fashion with the cytosolic leaflet of the membrane, possibly involving the basic M3/M4 loop. The expression of a mutant RyR1, Delta4274-4535, deleted in the sequence surrounding both M3 and M4, restored robust, voltage-gated L-type Ca(2+) currents and Ca(2+) transients in dyspedic myotubes, demonstrating that this sequence is not required for either orthograde (DHPR activation of sarcoplasmic reticulum Ca(2+) release) or retrograde (RyR1 increase in DHPR Ca(2+) channel activity) signals of excitation-contraction coupling. Maximal amplitudes of L-currents and Ca(2+) transients with Delta4274-4535 were larger than with wild-type RyR1, and voltage-gated sarcoplasmic reticulum Ca(2+) release was more sensitive to activation by sarcolemmal voltage sensors. Thus, this region may act as a negative regulatory module that increases the energy barrier for Ca(2+) release channel opening. 相似文献
128.
129.
Summary Phosphatase activity was studied in the cambium and differentiating vascular cells of beech by using a modified Washstein and Meisel method. After fixation in glutaraldehyde or crotonaldehyde and incubation in a medium containing ATP and lead nitrate at pH 7.2, a deposit of electron-opaque granules was found in the nucleoli, nucleoplasm, nuclear envelope, endoplasmic reticulum, plastids, mitochondria, and at the plasmalemma. Although located at these different sites, the distribution varied both inter- and intra-cellularly. This is thought to be a true reflection of the variation in activity between closely adjacent cells in this part of the stem.Some reaction was obtained when ADP replaced ATP in the reaction mixture, but there was no reaction at all when both ATP and ADP were omitted. Fixation in hydroxyadipaldehyde, or incubation at pH 6.4 both produced very little reaction. 相似文献