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981.
Apocynin, a potent inhibitor of NADPH-oxidase, was widely studied for activities in diseases such as inflammation-mediated disorders, asthma and cardiovascular diseases. In our recent study, a novel nitrone derivative of apocynin, AN-1, demonstrated potent inhibition to oxidative injury and to high expression of gp91phox subunit of NADPH-oxidase induced by tert-butyl hydroperoxide (t-BHP) in RAW 264.7 macrophage cells, and displayed promising preclinical protective effect against lipopolysaccharide (LPS)-induced acute lung injury in rats. In this work, the pharmacokinetic behaviors of AN-1 in Sprague-Dawley rats with single intravenous and intragastric doses were investigated for further development. Furthermore, apocynin’s pharmacokinetics remain lacking, even though its pharmacological action has been extensively evaluated. The pharmacokinetics of parent apocynin were also comparatively characterized. A simple HPLC method was developed and validated to determine both AN-1 and apocynin in rat plasma. The chromatographic separation was achieved on an Agilent HC-C18 column (250 mm×4.6 mm, 5 µm) at an isocratic flow rate of 1.0 mL/min, with the mobile phase of methanol and water (53∶47, v/v) and the UV detection set at 279 nm. Good linearity was established over the concentration range of 0.1–500 µg/mL for AN-1 and 0.2–100 µg/mL for apocynin. The absolute recovery, precision and accuracy were satisfactory. Compared with the parent compound apocynin, AN-1 yielded a much longer T1/2 (AN-1 179.8 min, apocynin 6.1 min) and higher AUC0–t (AN-1 61.89 mmol/L·min, apocynin 2.49 mmol/L·min) after equimolar intravenous dosing (0.302 mmol/kg). The absolute bioavailability of oral AN-1 was 78%, but that of apocynin was only 2.8%. The significant improvement of pharmacokinetic behavior might be accounted for the effective pharmacodynamic results we documented for the novel nitrone derivative AN-1. 相似文献
982.
Jin-Ha Yoon Sung-Kyung Kim Ho-June Choi Soo-In Choi So-Youn Cha Sang-Baek Koh Hee-Taik Kang Song Vogue Ahn 《PloS one》2013,8(10)
Background
This study evaluated the relation between adiponectin and atherosclerosis in both genders, and investigated whether adiponectin provides useful additional information for assessing the risk of atherosclerosis.Methods
We measured serum adiponectin levels and other cardiovascular risk factors in 1033 subjects (454 men, 579 women) from the Korean Genomic Rural Cohort study. Carotid intima–media-thickness (CIMT) was used as measure of atherosclerosis. Odds ratios (ORs) with 95% confidence intervals (95% CI) were calculated using multiple logistic regression, and receiver operating characteristic curves (ROC), the category-free net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated.Results
After adjustment for conventional cardiovascular risk factors, such as age, waist circumference, smoking history, low-density and high-density lipoprotein cholesterol, triglycerides, systolic blood pressure and insulin resistance, the ORs (95%CI) of the third tertile adiponectin group were 0.42 (0.25–0.72) in men and 0.47 (0.29–0.75) in women. The area under the curve (AUC) on the ROC analysis increased significantly by 0.025 in men and 0.022 in women when adiponectin was added to the logistic model of conventional cardiovascular risk factors (AUC in men: 0.655 to 0.680, p = 0.038; AUC in women: 0.654 to 0.676, p = 0.041). The NRI was 0.32 (95%CI: 0.13–0.50, p<0.001), and the IDI was 0.03 (95%CI: 0.01–0.04, p<0.001) for men. For women, the category-free NRI was 0.18 (95%CI: 0.02–0.34, p = 0.031) and the IDI was 0.003 (95%CI: −0.002–0.008, p = 0.189).Conclusion
Adiponectin and atherosclerosis were significantly related in both genders, and these relationships were independent of conventional cardiovascular risk factors. Furthermore, adiponectin provided additional information to conventional cardiovascular risk factors regarding the risk of atherosclerosis. 相似文献983.
Immobilization of permeabilized whole cell penicillin G acylase from Alcaligenes faecalis using pore matrix crosslinked with glutaraldehyde 总被引:1,自引:0,他引:1
The activity of penicillin G acylase from Alcaligenes faecalis increased 7.5-fold when cells were permeabilized with 0.3% (w/v) CTAB. The treated cells were entrapped by polyvinyl alcohol crosslinked with boric acid, and crosslinked with 2% (v/v) glutaraldehyde to increase the stability. The conversion yield of penicillin G to 6-aminopenicillanic acid was 75% by immobilized system in batch reaction. No activity was lost after 15 cycles and about 65% enzyme activity was retained at the end of the 31th cycle. 相似文献
984.
Jian Liu Ming Dong Shi Li Miao Zhen Yu Li Ming Hua Song Ren Qing Wang 《Biological invasions》2006,8(7):1461-1470
Biological invasions have become a significant threat to the global environment. Unfortunately, to date there is no consensus
on invasion mechanisms and predictive models. Controversies range from whether we can reliably predict which species may become
invasive to which species characteristics (e.g., life history, taxonomic groups, or geographic origin) contribute to the invasion
processes. We examined 126 invasive alien plant species in China to understand the role of clonality and geographical origin
in their invasion success. These species were categorized into three groups (I, II, III) based on their invasiveness in terms
of current spatial occupation and the degree of damage to invaded habitats. Clonal plants consisted of almost half (44%) of
the 126 invasive species studied, and consisted of 66% of 32 the most invasive alien plant species (Group I). There was a
significant positive relationship between clonality and species invasiveness. A 68% of the 126 species studied originated
in the continent of America (North and/or South America). These preliminary findings support that America is the primary geographical
origin of invasive alien plant species in China and that clonality of the invasive plant species contributed significantly
to the their invasiveness. The results suggest an urgent need at the global scale to investigate the mechanisms whereby plant
clonal growth influences plant invasions, and the need for a focus at regional scale to examine factors affecting the exchange
of invasive plant species between America and China. 相似文献
985.
Xing Shun Song Chun Lan Tiao Kai Shi Wei Hua Mao Joshua Otieno Ogweno Yan Hong Zhou Jing Quan Yu 《Plant Growth Regulation》2006,49(1):85-93
In order to clarify the response of antioxidant systems in various cellular organelles to photo-oxidative stress, the activities
of superoxide dismutase (SOD) and enzymes of the ascorbate–glutathione (AsA-GSH) cycle were investigated in chloroplasts,
mitochondria and cytosol of cucumber leaves subjected to methyl viologen (MV) treatment. Photo-oxidation by MV resulted in
significant reductions in net photosynthetic rate (Pn) and increases in the ratio of the quantum efficiency of photosystem
II (PSII),
ΦPSII to that of the quantum efficiency of CO2 fixation (ΦCO2), followed by increased activities of SOD, and a general increase of AsA-GSH cycle enzymes in chloroplasts, mitochondria
and cytosol. These increases were however, most significant in chloroplasts. There were also significant increases in dehydroascorbate
(DHA), reduced glutathione (GSH), and oxidized glutathione (GSSG) except that the content of ascorbate (AsA) in chloroplasts
and cytosol was slightly decreased and little effected, respectively. However, GSSG in mitochondria and GSH in cytosol were
little influenced by the MV treatment. The activity of ascorbate oxidase (AO) in these organelles was independent of the MV
treatment while the activity of l-galactono-1,4- lactone dehydrogenase (GLDH) in mitochondria was slightly inhibited by MV treatment. These results indicate
that disturbance of electron transport in chloroplasts by MV influenced the metabolism of whole cell by a crosstalk signaling
system and that the AsA-GSH cycle played a primary role in sustaining the levels of AsA. 相似文献
986.
Lei Wu Xiaolu Jiao Dezhi Zhang Yalin Cheng Gang Song Yanhua Qu Fumin Lei 《Current Genomics》2021,22(7):496
Genomic data are important for understanding the origin and evolution of traits. Under the context of rapidly developing of sequencing technologies and more widely available genome sequences, researchers are able to study evolutionary mechanisms of traits via comparative genomic methods. Compared with other vertebrates, bird genomes are relatively small and exhibit conserved synteny with few repetitive elements, which makes them suitable for evolutionary studies. Increasing genomic progress has been reported on the evolution of powered flight, body size variation, beak morphology, plumage colouration, high-elevation colonization, migration, and vocalization. By summarizing previous studies, we demonstrate the genetic bases of trait evolution, highlighting the roles of small-scale sequence variation, genomic structural variation, and changes in gene interaction networks. We suggest that future studies should focus on improving the quality of reference genomes, exploring the evolution of regulatory elements and networks, and combining genomic data with morphological, ecological, behavioural, and developmental biology data. 相似文献
987.
Synthesis and application of thiol‐functionalized magnetic nanoparticles for studying interactions of epirubicin hydrochloride with bovine serum albumin by fluorescence spectrometry 下载免费PDF全文
Huixia Xiong Quanping Diao Rui Jin Daqian Song Xinghua Wang Ying Sun 《Luminescence》2017,32(2):142-148
A novel method was developed for studying the interaction between epirubicin hydrochloride (EPI) and bovine serum albumin (BSA) by fluorescence spectrometry. Fe3O4 magnetic nanoparticles (MNPs) synthesized and functionalized with thiol group were employed for the immobilization and separation of target BSA in reaction solutions. The concentrations of the non‐immobilized BSA and unbound EPI were obtained separately by fluorescence spectrometry. The binding constants (K a ) and number of binding sites (n ) of EPI with BSA were calculated. In this study, the K a value was 5.05 × 105 L mol?1, suggesting a strong binding of EPI to BSA, and the n value was 1.15. The effects of common metal ions on K a of EPI with BSA were also investigated, and the results showed there was clearly bindings between the metal ions and BSA. The precise binding sites of EPI on BSA were determined as being in site I from the competitive displacement experiments. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
988.
Allozyme variation at eleven loci encoding seven enzyme systems were examined in 20 populations of diploid (genome AA, 2n = 16)Scilla scilloides in China. In comparison with the average species of seed plants studied, populations of this species display a high amount of genetic variation (A = 2.0, P = 58.6%, Ho = 0.172, and He = 0.185). Allozyme variation pattern revealed predominant outcrossing within populations and considerable differentiation (FST = 0.314) among populations as well as between the subtropic and temperate regions. The wide distribution, long existence and outcrossing are presumably the main factors responsible for the high genetic diversity within populations. But the gravity dispersal of seeds and pollination by small insects set limits to the increase of genetic variation within populations and promote differentiation between populations and regions. In addition, allozyme variation does not distinguishS. scilloides var.albo-viridis and suggests that subtropic populations may be considered as a genetic entity. 相似文献
989.
Do Geum-Sook Seo Bong-Bo Ko Jong-Min Lee Seon-Hee Pak Jae-Hong Kim In-Sun Song Seung-Dal 《Plant Cell, Tissue and Organ Culture》1999,57(2):113-119
The effects of basal media and growth regulators on callus initiation and shoot regeneration have been investigated in wild
Allium tuberosum (2n = 4x = 32). Callus initiation was greatest from flower bud explants cultured on MS medium supplemented
with 2,4-D and BA at 1 mg l−1 each. Maximum number of shoots was obtained from callus grown on MS medium supplemented with NAA and BA at 0.2 and 2 mg l−1, respectively. The chromosome analysis of regenerants derived from callus revealed variation in ploidy, such as 2n = 28,
29, 30, 31, 33 as well as normal tetraploid. During the culture period for two generations, one aneuploid regenerant with
2n = 30 (named At30) showed better viability and growth than tetraploid plants and other aneuploid variants. In a karyotypic
analysis of At30, the chromosomal positions of 5S and 18S-5.8S-26S rDNA were physically mapped by fluorescent in situ hybridization
and compared to chromosomes of wild type A. tuberosum. Both wild type A. tuberosum and At30 exhibited two sets of 5S rDNA
sites, one on the proximal position of the short arm of chromosome 3, and the other on the intercalary region on the long
arm of chromosome 6. There was one 18S-5.8S-26S rDNA site in the secondary constriction including flanking short chromosomal
segments of satellite and terminal regions on the short arm of chromosome 8 in wild type A. tuberosum. However, At30 showed
only three labelled chromosome 8 indicating that this was one of the lost chromosomes of At30.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
990.
Guanhua Deng Linbo Cai Jian Feng Song Duan Ping Zhang Sherman X. Xin 《Bioelectromagnetics》2021,42(1):86-94
Artificial materials that can simultaneously mimic the relative permittivity and conductivity of various human tissues are usually used in medical applications. However, the method of precisely designing these materials with designated values of both relative permittivity and conductivity at 3 T MRI resonance frequency is lacking. In this study, a reliable method is established to determine the compositions of artificial dielectric materials with designated relative permittivity and conductivity at 128 MHz. Sixty dielectric materials were produced using oil, sodium chloride, gelatin, and deionized water as the main raw materials. The dielectric properties of these dielectric materials were measured using the open‐ended coaxial line method at 128 MHz. Nonlinear least‐squares Marquardt–Levenberg algorithm was used to obtain the formula, establishing the relationship between the compositions of the dielectric materials and their dielectric properties at 128 MHz. The dielectric properties of the blood, gall bladder, muscle, skin, lung, and bone at 128 MHz were selected to verify the reliability of the obtained formula. For the obtained formula, the coefficient of determination and the expanded uncertainties with a coverage factor of k = 2 were 0.991% and 4.9% for relative permittivity and 0.992% and 6.4% for conductivity. For the obtained artificial materials measured using the open‐ended coaxial line method, the maximal difference of relative permittivity and conductivity were 1.0 and 0.02 S/m, respectively, with respect to the designated values. In conclusion, the compositions of tissue‐mimicking material can be quickly determined after the establishment of the formulas with the expanded uncertainties of less than 10%. Bioelectromagnetics. 2021;42:86–94. © 2020 Bioelectromagnetics Society. 相似文献