70 results on '"Lu QM"'
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2. Refractive index profiles in YCa4O(BO3)(3) and Nd : YCa4O(BO3)(3) waveguides created by MeV He ions
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Wang, KM, Hu, H., Chen, F., Lu, F., Shi, BR, Shen, DY, Liu, YG, Wang, JY, Lu, QM, Wang, KM, Hu, H., Chen, F., Lu, F., Shi, BR, Shen, DY, Liu, YG, Wang, JY, and Lu, QM
- Abstract
YCa4O(BO3)(3) (YCOB) is one of the rare-earth calcium oxyborate family of crystals. The crystal has good potential to be used for self-frequency doubling due to its excellent combination of nonlinear and laser properties. We have used MeV He+ ions to make waveguides in YCOB and Nd:YCOB (NdYCOB) crystals. The ion implantation was carried out with 2.8 MeV He+ ions at room temperature. The fluences have varied from 1.5 x 10(16) to 5.5 x 10(16) ions/cm(2). The model 2010 prism coupler was used to measure the modes in YCOB and NdYCOB waveguides formed by MeV He+ ion implantation. The refractive index profiles are fitted based on the reflectivity calculation method. We have used TRIM'98 simulation to get the range and damage profiles by MeV He+ ions in YCOB. Especially the refractive index change as a function of fluence is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
- Published
- 2002
3. Waveguide formation in LiTaO3 and LiB3O5 by keV hydrogen ion implantation
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Wang, KM, Chen, F., Hu, H., Zhang, JH, Lu, F., Shi, BR, Lu, QM, Ma, CQ, Wang, KM, Chen, F., Hu, H., Zhang, JH, Lu, F., Shi, BR, Lu, QM, and Ma, CQ
- Abstract
Lithium tantalate (LiTaO3) samples were implanted with HI ions at different energies from 250 to 350 keV using different doses. Lithium triborate (LiB3O5) Samples were implanted at 350 keV H+ ions with doses from 1 x 10(16) to 5 x 10(16) ions/cm(2) in increment of 1 X 10(16) ions/cm(2) at room temperature. The modes in LiTaO3 and LiB3O5 samples were measured by a model 2010 prism coupler. Two or three modes were observed in most cases. The change of the refractive index depends on the energy, dose and annealing temperature. Multi-energy implantation was used to broaden the optical barrier. There is a threshold dose of around 4 x 10(16) ions/cm(2) for LiB3O5 which is different from the case of LiTa03. The preliminary results show that the waveguide formation in LiTaO3 and LiB3O5 crystals is possible by using keV H+ ion implantation. (C) 2001 Elsevier Science B.V. All rights reserved.
- Published
- 2001
4. Inhibition of the P38 MAPK/NLRP3 pathway mitigates cognitive dysfunction and mood alterations in aged mice after abdominal surgery plus sevoflurane.
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Lv JM, Gao YL, Wang LY, Li BD, Shan YL, Wu ZQ, Lu QM, Peng HY, Zhou TT, Li XM, and Zhang LM
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- Animals, Male, Mice, Abdomen surgery, Aging metabolism, Anesthetics, Inhalation pharmacology, Laparotomy adverse effects, Mice, Inbred C57BL, Mice, Knockout, Mood Disorders metabolism, Postoperative Cognitive Complications metabolism, Postoperative Complications metabolism, Signal Transduction drug effects, Signal Transduction physiology, Cognitive Dysfunction metabolism, Cognitive Dysfunction etiology, NLR Family, Pyrin Domain-Containing 3 Protein metabolism, p38 Mitogen-Activated Protein Kinases metabolism, Sevoflurane pharmacology
- Abstract
Background: Cognitive dysfunction, encompassing perioperative psychological distress and cognitive impairment, is a prevalent postoperative complication within the elderly population, and in severe cases, it may lead to dementia. Building upon our prior research that unveiled a connection between postoperative mood fluctuations and cognitive dysfunction with the phosphorylation of P38, this present investigation aims to delve deeper into the involvement of the P38 MAPK/NLRP3 pathway in perioperative neurocognitive disorders (PND) in an abdominal exploratory laparotomy (AEL) aged mice model., Methods: C57BL/6 mice (male, 18-month-old) underwent AEL with 3 % anesthesia. Then, inhibitors targeting P38 MAPK (SB202190, 1 mg/kg) and GSK3β (TWS119, 10 mg/kg) were administered multiple times daily for 7 days post-surgery. The NLRP3-cKO AEL and WT AEL groups only underwent the AEL procedure. Behavioral assessments, including the open field test (OFT), novel object recognition (NOR), force swimming test (FST), and fear conditioning (FC), were initiated on postoperative day 14. Additionally, mice designated for neuroelectrophysiological monitoring had electrodes implanted on day 14 before surgery and underwent novel object recognition while their local field potential (LFP) was concurrently recorded on postoperative day 14. Lastly, after they were euthanasized, pathological analysis and western blot were performed., Results: SB202190, TWS119, and astrocyte-conditional knockout NLRP3 all ameliorated the cognitive impairment behaviors induced by AEL in mice and increased mean theta power during novel location exploration. However, it is worth noting that SB202190 may exacerbate postoperative depressive and anxiety-like behaviors in mice, while TWS119 may induce impulsive behaviors., Conclusions: Our study suggests that anesthesia and surgical procedures induce alterations in mood and cognition, which may be intricately linked to the P38 MAPK/NLRP3 pathway., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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5. Bat-derived oligopeptide LE6 inhibits the contact-kinin pathway and harbors anti-thromboinflammation and stroke potential.
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Cha LN, Yang J, Gao JA, Lu X, Chang XL, Thuku RC, Liu Q, Lu QM, Li DS, Lai R, and Fang MQ
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- Animals, Mice, Chiroptera, Thrombosis, Inflammation, Male, Anti-Inflammatory Agents pharmacology, Oligopeptides pharmacology, Stroke drug therapy
- Abstract
Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke. The contact-kinin pathway, initiated by plasma kallikrein (PK) and activated factor XII (FXIIa), functions bidirectionally with the coagulation and inflammation cascades, providing a novel target for therapeutic drug development in ischemic stroke. In this study, we identified a bat-derived oligopeptide from Myotis myotis (Borkhausen, 1797), designated LE6 (Leu-Ser-Glu-Glu-Pro-Glu, 702 Da), with considerable potential in stroke therapy due to its effects on the contact kinin pathway. Notably, LE6 demonstrated significant inhibitory effects on PK and FXIIa, with inhibition constants of 43.97 μmol/L and 6.37 μmol/L, respectively. In vitro analyses revealed that LE6 prolonged plasma recalcification time and activated partial thromboplastin time. In murine models, LE6 effectively inhibited carrageenan-induced mouse tail thrombosis, FeCl
3 -induced carotid artery thrombosis, and photochemically induced intracerebral thrombosis. Furthermore, LE6 significantly decreased inflammation and stroke injury in transient middle cerebral artery occlusion models. Notably, the low toxicity, hemolytic activity, and bleeding risk of LE6, along with its synthetic simplicity, underscore its clinical applicability. In conclusion, as an inhibitor of FXIIa and PK, LE6 offers potential therapeutic benefits in stroke treatment by mitigating inflammation and preventing thrombus formation.- Published
- 2024
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6. Blap-6, a Novel Antifungal Peptide from the Chinese Medicinal Beetle Blaps rhynchopetera against Cryptococcus neoformans .
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Zhang LM, Zhou SW, Huang XS, Chen YF, Mwangi J, Fang YQ, Du T, Zhao M, Shi L, and Lu QM
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- Animals, Humans, Biofilms drug effects, Amino Acid Sequence, Cryptococcus neoformans drug effects, Antifungal Agents pharmacology, Antifungal Agents chemistry, Microbial Sensitivity Tests, Coleoptera microbiology, Coleoptera drug effects, Antimicrobial Peptides pharmacology, Antimicrobial Peptides chemistry
- Abstract
Cryptococcus neoformans ( C. neoformans ) is a pathogenic fungus that can cause life-threatening meningitis, particularly in individuals with compromised immune systems. The current standard treatment involves the combination of amphotericin B and azole drugs, but this regimen often leads to inevitable toxicity in patients. Therefore, there is an urgent need to develop new antifungal drugs with improved safety profiles. We screened antimicrobial peptides from the hemolymph transcriptome of Blaps rhynchopetera ( B. rhynchopetera ), a folk Chinese medicine. We found an antimicrobial peptide named blap-6 that exhibited potent activity against bacteria and fungi. Blap-6 is composed of 17 amino acids (KRCRFRIYRWGFPRRRF), and it has excellent antifungal activity against C. neoformans , with a minimum inhibitory concentration (MIC) of 0.81 μM. Blap-6 exhibits strong antifungal kinetic characteristics. Mechanistic studies revealed that blap-6 exerts its antifungal activity by penetrating and disrupting the integrity of the fungal cell membrane. In addition to its direct antifungal effect, blap-6 showed strong biofilm inhibition and scavenging activity. Notably, the peptide exhibited low hemolytic and cytotoxicity to human cells and may be a potential candidate antimicrobial drug for fungal infection caused by C. neoformans .
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- 2024
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7. Blapstin, a Diapause-Specific Peptide-Like Peptide from the Chinese Medicinal Beetle Blaps rhynchopetera , Has Antifungal Function.
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Zhang LM, Yang M, Zhou SW, Zhang H, Feng Y, Shi L, Li DS, Lu QM, Zhang ZH, and Zhao M
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- Animals, Child, Humans, Aged, Antifungal Agents therapeutic use, Candida albicans, Microbial Sensitivity Tests, Peptides pharmacology, Antimicrobial Peptides, Coleoptera, Dermatomycoses drug therapy
- Abstract
Drug resistance against bacteria and fungi has become common in recent years, and it is urgent to discover novel antimicrobial peptides to manage this problem. Many antimicrobial peptides from insects have been reported to have antifungal activity and are candidate molecules in the treatment of human diseases. In the present study, we characterized an antifungal peptide named blapstin that was isolated from the Chinese medicinal beetle Blaps rhynchopetera used in folk medicine. The complete coding sequence was cloned from the cDNA library prepared from the midgut of B. rhynchopetera . It is a 41-amino-acid diapause-specific peptide (DSP)-like peptide stabilized by three disulfide bridges and shows antifungal activity against Candida albicans and Trichophyton rubrum with MICs of 7 μM and 5.3 μM, respectively. The C. albicans and T. rubrum treated with blapstin showed irregular and shrunken cell membranes. In addition, blapstin inhibited the activity of C. albicans biofilm and showed little hemolytic or toxic activity on human cells and it is highly expressed in the fat body, followed by the hemolymph, midgut, muscle, and defensive glands. These results indicate that blapstin may help insects fight against fungi and showed a potential application in the development of antifungal reagents. IMPORTANCE Candida albicans is one of the conditional pathogenic fungi causing severe nosocomial infections. Trichophyton rubrum and other skin fungi are the main pathogens of superficial cutaneous fungal diseases, especially in children and the elderly. At present, antibiotics such as amphotericin B, ketoconazole, and fluconazole are the main drugs for the clinical treatment of C. albicans and T. rubrum infections. However, these drugs have certain acute toxicity. Long-term use can increase kidney damage and other side effects. Therefore, obtaining broad-spectrum antifungal drugs with high efficiency and low toxicity for the treatment of C. albicans and T. rubrum infections is a top priority. Blapstin is an antifungal peptide which shows activity against C. albicans and T. rubrum. The discovery of blapstin provides a novel clue for our understanding of the innate immunity of Blaps rhynchopetera and provides a template for designing antifungal drugs., Competing Interests: The authors declare no conflict of interest.
- Published
- 2023
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8. Identification and characterization of a novel elastase inhibitor from Hirudinaria manillensis.
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Xu KH, Zhou M, Wu FL, Tang XP, Lu QM, Lai R, and Long CB
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- Amino Acid Sequence, Animals, Proteins, Leeches chemistry, Pancreatic Elastase antagonists & inhibitors, Protease Inhibitors pharmacology
- Abstract
A large number of protease inhibitors have been found from leeches, which are essential in various physiological and biological processes. In the curret study, a novel elastase inhibitor was purified and characterized from the leech of Hirudinaria manillensis, which was named HMEI-A. Primary structure analysis showed that HMEI-A belonged to a new family of proteins. HMEI-A exerted inhibitory effects on elastase and showed potent abilities to inhibit elastase with an inhibition constant (K
i ) of 1.69 × 10-8 mol·L-1 . Further study showed that HMEI-A inhibited the formation of neutrophil extracellular trap (NET). These results suggested that HMEI-A from the leech of H. manillensis is a novel elastase inhibitor which can suppress NET formation. It may play a significant role in blood-sucking of leeches and is a potential candidate as an anti-inflammatory agent., (Copyright © 2021 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)- Published
- 2021
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9. Development of Faraday rotation measurements on Keda Reconnection eXperiment (KRX) device.
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Liu DK, Ding WX, Mao WZ, Zhang QF, Fan FB, Sang LL, Lu QM, and Xie JL
- Abstract
The Faraday-effect based polarimeter and interferometer are developed for non-perturbation magnetic field and density measurements on the Keda Reconnection eXperiment (KRX) device. The magnetic reconnection is externally driven by a pair of parallel current plates. To design this instrument and provide an alternative way to facilitate theory-experiment comparisons via forward modeling of the diagnostics process with full plasma dynamics given by simulation, we develop a synthetic diagnostics based on 2D photonic integrated circuit simulation for magnetic reconnection on the KRX. The view-line geometry is optimized and wavelengths (1 mm) of the polarimeter and interferometer are selected to ensure the sensitivity of measurement on the KRX. We have simulated magnetic reconnection on the x-line (x-z plane) with horizontal viewing and vertical viewing for line of sight measurements. It is found that the current sheet width and indicator of magnetic reconnection can be inferred directly from the dynamics of Faraday rotation even with the line-integrated character of polarimeter-interferometer diagnostics.
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- 2021
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10. Oxidation of dextran using H 2 O 2 and NaClO/NaBr and their applicability in iron chelation.
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Wu H, Shang-Guan DC, Lu QM, Hu XQ, Yang JW, and Zhang HB
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- Ferric Compounds chemistry, Hydrogen-Ion Concentration, Iron chemistry, Kinetics, Minerals chemistry, Molecular Weight, Oxidation-Reduction, Structure-Activity Relationship, Bromides chemistry, Coordination Complexes chemistry, Dextrans chemistry, Hydrogen Peroxide chemistry, Iron Chelating Agents chemistry, Sodium Compounds chemistry, Sodium Hypochlorite chemistry
- Abstract
The structural modification of polysaccharides directly affects their physicochemical properties and applications. Dextran, a chained polysaccharide, consists of multiple d-glucose molecules with repetitive structures. In this study, the physicochemical properties of oxidized dextran (DO) at different concentrations of NaClO/NaBr and H
2 O2 were compared. The results showed that NaClO/NaBr oxidation is more conducive to the formation of carboxyl groups. Oxidized dextran with NaClO/NaBr (DOB) showed good iron (III) chelating ability, and the DOB‑iron (III) complex (DOBIC) had an iron content of 28.31%. According to structural analysis, NaClO/NaBr (2 g/100 g of active chlorine) and H2 O2 (4 g/100 g), respectively, oxidize the C1 and C2 hydroxyl groups of dextran to carboxyl groups and open the ring when DO and iron have the strongest chelation ability. The complex is indeed a chelate iron complex, and iron core is composed of iron oxyhydroxide or the β-FeOOH mineral polymorph. These results indicate that DOBIC is expected to be a good iron supplement or food additive to strengthen iron., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2020
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11. The association of the CMIP rs16955379 polymorphism with dyslipidemia and the clinicopathological features of IgA nephropathy.
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Mo MQ, Pan L, Lu QM, Li QL, and Liao YH
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Immunoglobulin A nephropathy (IgAN) is among the most common primary glomerular diseases. The prognosis in IgAN is affected by dyslipidemia, a risk factor for cardiovascular disease. The c-Maf inducing protein (CMIP) gene has been found to be associated with lipid metabolism. But the association between the CMIP rs16955379 single nucleotide polymorphism (SNP) and dyslipidemia or the related clinicopathological features in IgAN have not been reported thus far. The present study investigated the correlation between them. The CMIP rs16955379 SNP genotypes of 300 subjects with IgAN recruited from the First Affiliated Hospital of Guangxi Medical University were identified by polymerase chain reaction and direct sequencing. Compared with the control (normal lipid) group, the dyslipidemia group with IgAN had higher blood uric acid, serum creatinine, blood urea nitrogen and urinary protein quantity, higher proportions of mesangial cell proliferation and renal tubular atrophy/interstitial fibrosis (IFTA), and a lower estimated glomerular filtration rate and serum albumin. The frequencies of the CMIP rs16955379 SNP TT genotype and T allele in the dyslipidemia group were higher than in the control group. Triglyceride, apolipoprotein A1 (ApoA1), ApoA1/B, incidences of mesangial cell proliferation, and IFTA were higher in TT genotype carriers than in CC/CT genotype carriers. Serum lipid profiles and dyslipidemia were significantly associated with renal dysfunction and IFTA. IgAN patients with the TT genotype were more likely to have dyslipidemia, renal dysfunction and IFTA (P < 0.05 for all above). These results indicate that CMIP rs16955379 SNP may be a genetic susceptibility gene for dyslipidemia and poor renal outcome in IgAN., Competing Interests: None., (IJCEP Copyright © 2018.)
- Published
- 2018
12. [Effect of fracture of lower limbs with hemorrhage on myocardial injury and its mechanism in rats].
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Li ZH, Zhang Y, Lu Y, Lu QM, and Xie XH
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- Animals, Cells, Cultured, Cytokines blood, Follow-Up Studies, Lower Extremity pathology, Myocytes, Cardiac pathology, Proto-Oncogene Proteins c-bcl-2 metabolism, Random Allocation, Rats, Rats, Sprague-Dawley, bcl-2-Associated X Protein metabolism, Apoptosis, Fractures, Bone complications, Hemorrhage complications, Myocardium pathology
- Abstract
Objectives: To test whether myocardial apoptosis can be induced by traumatic fracture of lower limbs with hemorrhage, in order to lay a foundation of myocardial injury after traumatic fracture for the follow-up study., Methods: Twenty SD rats were randomly divided into two groups, i. e. control group and trauma group( n =10). A rat model of traumatic hemorrhage was establish, and a traumatic model of the original generation of myocardial cell culture was constructed in vitro . The level of interleukin-2(IL-2),IL-6,IL-10 and tumor necrosis factor-α(TNF-α) in rat serum was detected by ELISA at 0, 1, 2, 4, 8, 12, 16, 24 and 48 hour to find the most significant point. The pathological cardiac injury in rats was observed by HE staining under a microscope, and the apoptosis of cultured cardiomyocyte in vitro was detected by TUNEL methods. The expressions of apoptosis gene,(Bcl-2) and Bax, in myocardium of rat and cultured cardiomyocyte in vitro were detected by Western blot and RT-PCR., Results: At the 4
th hour after trauma, IL-6 and IL-10 in the serum of rats reached its highest, IL-2 reached its lowest at the 8th hour after trauma, and TNF-αreached its highest at 1 hour after trauma, then all recovered to their normol level gradually. Myocardial HE staining indicated that cardiomyocyte was swelling, disordered derangement, inflammatory cell infiltrated; a large number of myocardial cell nuclei was dyedbrown in TUNEL test which proved that the apoptosis index increased ( P <0.05). Western blot and RT-PCR results showed that the expression of pro-apoptotic gene Bax was up-regulated ( P <0. 05), while expression of anti apoptosis gene Bcl-2 down-regulated ( P <0.05)., Conclusions: The myocardial apoptosis can be induced by traumatic fracture of lower limbs with hemorrhage in rats, and then lead to myocardial injury.- Published
- 2018
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13. Association between Allergic Diseases and Irritable Bowel Syndrome: A Retrospective Study.
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Fang ZY, Zhang HT, Lu C, Lu QM, Yu CH, and Wang HY
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- Adult, Case-Control Studies, Female, Humans, Male, Retrospective Studies, Surveys and Questionnaires, Hypersensitivity complications, Immunoglobulin E blood, Irritable Bowel Syndrome complications
- Abstract
Background: The relationship between allergic disease and irritable bowel syndrome (IBS) is poorly understood. We aimed to investigate the potential association as well as the underlying immunological mechanisms., Methods: A retrospective case-control study of 108 atopic patients from among outpatients in an allergy clinic (allergic rhinitis [AR], n = 49; chronic urticaria [CU], n = 59) and 74 controls from among ward companions was conducted from November 2016 to March 2017. The detection rates and related gastrointestinal (GI) symptoms of IBS, as well as immunological indices, were calculated., Results: CU patients had a trend of increase in the detection of IBS compared to controls (OR = 4.846; 95% CI 0.967-24.279, p = 0.077). Loose stools (OR = 2.406; 95% CI 1.075-5.386, p < 0.05) and viscous stools (OR = 2.665; 95% CI 1.250-5.682, p < 0.05) were more common in CU patients. Atopic patients positive for serum total immunoglobulin E (IgE) (OR = 3.379; 95% CI 1.088-10.498, p < 0.05) or house dust mite (HDM)-specific IgE (OR = 3.640; 95% CI 1.228-10.790, p < 0.05) were more likely to have abdominal bloating. Besides, a positive association between levels of total IgE and severity of abdominal bloating was observed (p < 0.05). An HDM-specific IgE-positive reaction was independently associated with abdominal bloating in atopic patients (p < 0.05)., Conclusions: Allergic disease has a clear clinical association with IBS with more frequent and severe symptoms of IBS. CU patients have a tendency to suffer from IBS, usually with diarrhea. Serum total IgE and HDM-specific IgE are positively correlated with GI symptoms in atopic patients., (© 2018 S. Karger AG, Basel.)
- Published
- 2018
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14. Assessment of signature handwriting evidence via score-based likelihood ratio based on comparative measurement of relevant dynamic features.
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Chen XH, Champod C, Yang X, Shi SP, Luo YW, Wang N, Wang YC, and Lu QM
- Abstract
This paper extends on previous research on the extraction and statistical analysis on relevant dynamic features (width, grayscale and radian combined with writing sequence information) in forensic handwriting examinations. In this paper, a larger signature database was gathered, including genuine signatures, freehand imitation signatures, random forgeries and tracing imitation signatures, which are often encountered in casework. After applying Principle Component Analysis (PCA) of the variables describing the proximity between specimens, a two-dimensional kernel density estimation was used to describe the variability of within-genuine comparisons and genuine-forgery comparisons. We show that the overlap between the within-genuine comparisons and the genuine-forgery comparisons depends on the imitated writer and on the forger as well. Then, in order to simulate casework conditions, cases were simulated by random sampling based on the collected signature dataset. Three-dimensional normal density estimation was used to estimate the numerator and denominator probability distribution used to compute a likelihood ratio (LR). The comparisons between the performance of the systems in SigComp2011 (based on static features) and the method presented in this paper (based on relevant dynamic features) showed that relevant dynamic features are better than static features in terms of accuracy, false acceptance rate, false rejection rate and calibration of likelihood ratios., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2018
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15. Satellite-based entanglement distribution over 1200 kilometers.
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Yin J, Cao Y, Li YH, Liao SK, Zhang L, Ren JG, Cai WQ, Liu WY, Li B, Dai H, Li GB, Lu QM, Gong YH, Xu Y, Li SL, Li FZ, Yin YY, Jiang ZQ, Li M, Jia JJ, Ren G, He D, Zhou YL, Zhang XX, Wang N, Chang X, Zhu ZC, Liu NL, Chen YA, Lu CY, Shu R, Peng CZ, Wang JY, and Pan JW
- Abstract
Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers., (Copyright © 2017, American Association for the Advancement of Science.)
- Published
- 2017
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16. Protease inhibitor in scorpion (Mesobuthus eupeus) venom prolongs the biological activities of the crude venom.
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Ma H, Xiao-Peng T, Yang SL, Lu QM, and Lai R
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- Amino Acid Sequence, Animals, Base Sequence, Female, Kinetics, Male, Mice, Molecular Sequence Data, Protease Inhibitors toxicity, Scorpion Venoms genetics, Scorpion Venoms toxicity, Scorpions genetics, Trypsin chemistry, Protease Inhibitors chemistry, Scorpion Venoms chemistry, Scorpions chemistry
- Abstract
It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named MeKTT-1, belonged to Kunitz-type toxins subfamily. Native MeKTT-1 selectively inhibited trypsin with a Kivalue of 130 nmol·L(-1). Furthermore, MeKTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, MeKTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival., (Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)
- Published
- 2016
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17. Chinese physicians' perceptions of fecal microbiota transplantation.
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Ren RR, Sun G, Yang YS, Peng LH, Wang SF, Shi XH, Zhao JQ, Ban YL, Pan F, Wang XH, Lu W, Ren JL, Song Y, Wang JB, Lu QM, Bai WY, Wu XP, Wang ZK, Zhang XM, and Chen Y
- Subjects
- Adult, Aged, Aged, 80 and over, Awareness, China, Female, Gastrointestinal Diseases diagnosis, Gastrointestinal Diseases microbiology, Humans, Male, Middle Aged, Specialization, Surveys and Questionnaires, Young Adult, Attitude of Health Personnel, Fecal Microbiota Transplantation, Gastrointestinal Diseases therapy, Health Knowledge, Attitudes, Practice, Perception, Physicians psychology
- Abstract
Aim: To explore Chinese physicians' perceptions towards fecal microbiota transplantation (FMT) and to provide information and an assessment of FMT development in China., Methods: A self-administered questionnaire was developed according to the FMT practice guidelines and was distributed to physicians in hospitals via Internet Research Electronic Data Capture (REDcap) software and electronic mails to assess their attitudes toward and knowledge of FMT. The questionnaire included a brief introduction of FMT that was followed by 20 questions. The participants were required to respond voluntarily, under the condition of anonymity and without compensation. Except for the fill-in-the-blank questions, all of the other questions were required in the REDcap data collection systems, and the emailed questionnaires were completed based on eligibility., Results: Up to December 9, 2014, 844 eligible questionnaires were received out of the 980 distributed questionnaires, with a response rate of 86.1%. Among the participants, 87.3% were from tertiary hospitals, and there were 647 (76.7%) gastroenterologists and 197 (23.3%) physicians in other departments (non-gastroenterologists). Gastroenterologists' awareness of FMT prior to the survey was much higher than non-gastroenterologists' (54.3 vs 16.5%, P < 0.001); however, acceptance of FMT was not statistically different (92.4 vs 87.1%, P = 0.1603). Major concerns of FMT included the following: acceptability to patients (79.2%), absence of guidelines (56.9%), and administration and ethics (46.5%). On the basis of understanding, the FMT indications preferred by physicians were recurrent Clostridium difficile infection (86.7%), inflammatory bowel disease combined with Clostridium difficile infection (78.6%), refractory ulcerative colitis (70.9%), ulcerative colitis (65.4%), Crohn's disease (59.4%), chronic constipation (43.7%), irritable bowel syndrome (39.1%), obesity (28.1%) and type 2 diabetes (23.9%). For donor selection, the majority of physicians preferred individuals with a similar gut flora environment to the recipients. 76.6% of physicians chose lower gastrointestinal tract as the administration approach. 69.2% of physicians considered FMT a safe treatment., Conclusion: Chinese physicians have awareness and a high acceptance of FMT, especially gastroenterologists, which provides the grounds and conditions for the development of this novel treatment in China. Physicians' greatest concerns were patient acceptability and absence of guidelines.
- Published
- 2016
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18. Intrinsic magnetic properties of single-phase Mn(1+x)Ga (0<x<1) alloys.
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Lu QM, Yue M, Zhang HG, Wang ML, Yu F, Huang QZ, Ryan DH, and Altounian Z
- Abstract
Magnetization measurements have been carried out on a series of carefully prepared single-phase Mn(1+x)Ga (0
- Published
- 2015
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19. A Novel Trypsin Inhibitor-Like Cysteine-Rich Peptide from the Frog Lepidobatrachus laevis Containing Proteinase-Inhibiting Activity.
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Wang YW, Tan JM, Du CW, Luan N, Yan XW, Lai R, and Lu QM
- Abstract
Various bio-active substances in amphibian skins play important roles in survival of the amphibians. Many protease inhibitor peptides have been identified from amphibian skins, which are supposed to negatively modulate the activity of proteases to avoid premature degradation or release of skin peptides, or to inhibit extracellular proteases produced by invading bacteria. However, there is no information on the proteinase inhibitors from the frog Lepidobatrachus laevis which is unique in South America. In this work, a cDNA encoding a novel trypsin inhibitor-like (TIL) cysteine-rich peptide was identified from the skin cDNA library of L. laevis. The 240-bp coding region encodes an 80-amino acid residue precursor protein containing 10 half-cysteines. By sequence comparison and signal peptide prediction, the precursor was predicted to release a 55-amino acid mature peptide with amino acid sequence, IRCPKDKIYKFCGSPCPPSCKDLTPNCIAVCKKGCFCRDGTVDNNHGKCVKKENC. The mature peptide was named LL-TIL. LL-TIL shares significant domain similarity with the peptides from the TIL supper family. Antimicrobial and trypsin-inhibitory abilities of recombinant LL-TIL were tested. Recombinant LL-TIL showed no antimicrobial activity, while it had trypsin-inhibiting activity with a Ki of 16.5178 μM. These results suggested there was TIL peptide with proteinase-inhibiting activity in the skin of frog L. laevis. To the best of our knowledge, this is the first report of TIL peptide from frog skin.
- Published
- 2015
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20. Purification and characterization of cholecystokinin from the skin of salamander Tylototriton verrucosus.
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Jiang WB, Hakim M, Luo L, Li BW, Yang SL, Song YZ, Lai R, and Lu QM
- Subjects
- Amino Acid Sequence, Amphibian Proteins chemistry, Amphibian Proteins genetics, Animals, Base Sequence, Cholecystokinin chemistry, Cholecystokinin genetics, Female, Male, Molecular Sequence Data, Muscle Contraction drug effects, Muscle, Smooth drug effects, Muscle, Smooth physiology, Skin metabolism, Swine, Urodela metabolism, Amphibian Proteins isolation & purification, Amphibian Proteins pharmacology, Cholecystokinin isolation & purification, Cholecystokinin pharmacology, Skin chemistry, Urodela genetics
- Abstract
As a group of intestinal hormones and neurotransmitters, cholecystokinins (CCKs) regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A cDNA encoding the CCK precursor containing 129 amino acid residues was cloned from the cDNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0 x 10⁻¹¹ mol/L and inducing maximal contraction at a concentration of 2.0 x 10⁻⁶ mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.
- Published
- 2015
21. Process development of short-chain polyols synthesis from corn stover by combination of enzymatic hydrolysis and catalytic hydrogenolysis.
- Author
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Fang ZH, Zhang J, Lu QM, and Bao J
- Abstract
Currently short-chain polyols such as ethanediol, propanediol, and butanediol are produced either from the petroleum feedstock or from the starch-based food crop feedstock. In this study, a combinational process of enzymatic hydrolysis with catalytic hydrogenolysis for short-chain polyols production using corn stover as feedstock was developed. The enzymatic hydrolysis of the pretreated corn stover was optimized to produce stover sugars at the minimum cost. Then the stover sugars were purified and hydrogenolyzed into polyols products catalyzed by Raney nickel catalyst. The results show that the yield of short-chain polyols from the stover sugars was comparable to that of the corn-based glucose. The present study provided an important prototype for polyols production from lignocellulose to replace the petroleum- or corn-based polyols for future industrial applications.
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- 2014
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22. [Expression of vascular growth factors in intestinal tissues in colorectal carcinoma patients with schistosomiasis japonica].
- Author
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Ruan SL, Wang B, Lu QM, Dong LR, Cao CX, Xu SL, and Shen WY
- Subjects
- Adult, Aged, Animals, Colorectal Neoplasms metabolism, Colorectal Neoplasms parasitology, Female, Gene Expression, Humans, Male, Middle Aged, Schistosoma japonicum isolation & purification, Schistosoma japonicum physiology, Schistosomiasis japonica metabolism, Schistosomiasis japonica parasitology, Thymidine Phosphorylase metabolism, Vascular Endothelial Growth Factor A metabolism, Colorectal Neoplasms genetics, Intestinal Mucosa metabolism, Schistosomiasis japonica genetics, Thymidine Phosphorylase genetics, Vascular Endothelial Growth Factor A genetics
- Abstract
Objective: To investigate the differences of mRNA quantitation and protein expression of vascular growth factors including platelet-derived endothelial cell growth factor (PD-ECGF) and vascular endothelial growth factor (VEGF) in intestinal tissues in colorectal carcinoma patients with and without schistosomiasis., Methods: Thirty colorectal carcinoma patients with schistosomiasis and 30 colorectal carcinoma patients without schistosomiasis were included in this study. The mRNA quantitation and protein expression of PD-ECGF and VEGF in the normal tissue, peri-carcinoma tissue as well as carcinoma tissue obtained from surgical specimens were detected by qRT-PCR and Western blot., Results: The mRNA relative quantitations of PD-ECGF in normal tissue, peri-carcinoma tissue and carcinoma tissue in the colorectal carcinoma patients with schistosomiasis were 1.726, 1.766 and 2.729 times to those in the colorectal carcinoma patients without schistosomiasis, respectively. The corresponding ones of VEGF were 2.138, 1.831 and 3.376 times, respectively. The protein expression levels of PD-ECGF and VEGF in normal tissue, peri-carcinoma tissue and carcinoma tissue were higher in the colorectal carcinoma patients with schistosomiasis than in the colorectal carcinoma patients without schistosomiasis., Conclusions: The expressions of vascular growth factors including PD-ECGF and VEGF are higher in the colorectal carcinoma patients with schistosomiasis than in the colorectal carcinoma patients without schistosomiasis. Therefore, schistosomiasis may be one of the risk factors of colorectal cancer.
- Published
- 2013
23. [Clinical investigation on schistosomiasis after a 16-year-interruption program regarding its transmission, in Jiaxing region of Zhejiang province].
- Author
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Ruan SL, Lu QM, Yang ZH, Yu YW, and Tang LL
- Subjects
- Adult, Aged, Aged, 80 and over, China epidemiology, Female, Humans, Male, Middle Aged, Retrospective Studies, Schistosomiasis transmission, Schistosomiasis epidemiology, Schistosomiasis prevention & control
- Abstract
Objective: To investigate the epidemic pattern, diagnosis and treatment of schistosomiasis after the 16-years intervention program on its transmission in Jiaxing region of Zhejiang province., Methods: Clinical data of schistosomiasis patients during the last 10 years and pathological specimens with deposited schistosomal eggs during the last 8 years were retrospectively analyzed., Results: The total numbers of schistosomiasis patients admitted to hospital increased from 194 in 2001 to 960 in 2010, and from 78 to 266 with complications. Number of the ones with accompanied diseases increased from 116 to 694. All the numbers of the above said three groups showed an yearly increase. The hardest hit age of the patients was between 60 and 74. The number of specimens with deposited schistosomal eggs increased from 192 in 2003 to 298 in 2010. While the ratio of specimens with deposited schistosomal eggs to the total number of pathological specimens became slightly decreasing, the average age of patients increased. Eggs were mainly deposited on appendix, colon, rectum, stomach, liver, gallbladder and small intestine., Conclusion: Schistosomiasis still hit the Jiaxing region, with the average age of patients increased.
- Published
- 2013
24. Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction.
- Author
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Dong QL, Wang SJ, Lu QM, Huang C, Yuan DW, Liu X, Lin XX, Li YT, Wei HG, Zhong JY, Shi JR, Jiang SE, Ding YK, Jiang BB, Du K, He XT, Yu MY, Liu CS, Wang S, Tang YJ, Zhu JQ, Zhao G, Sheng ZM, and Zhang J
- Abstract
Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike electron outflow region including three well-collimated electron jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.
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- 2012
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25. Magnetic reconnection in the near Venusian magnetotail.
- Author
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Zhang TL, Lu QM, Baumjohann W, Russell CT, Fedorov A, Barabash S, Coates AJ, Du AM, Cao JB, Nakamura R, Teh WL, Wang RS, Dou XK, Wang S, Glassmeier KH, Auster HU, and Balikhin M
- Abstract
Observations with the Venus Express magnetometer and low-energy particle detector revealed magnetic field and plasma behavior in the near-Venus wake that is symptomatic of magnetic reconnection, a process that occurs in Earth's magnetotail but is not expected in the magnetotail of a nonmagnetized planet such as Venus. On 15 May 2006, the plasma flow in this region was toward the planet, and the magnetic field component transverse to the flow was reversed. Magnetic reconnection is a plasma process that changes the topology of the magnetic field and results in energy exchange between the magnetic field and the plasma. Thus, the energetics of the Venus magnetotail resembles that of the terrestrial tail, where energy is stored and later released from the magnetic field to the plasma.
- Published
- 2012
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26. Jerdonuxin, a novel snaclec (snake C-type lectin) with platelet aggregation activity from Trimeresurus jerdonii venom.
- Author
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Chen ZM, Wu JB, Zhang Y, Yu GY, Lee WH, Lu QM, and Zhang Y
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cloning, Molecular, Crotalid Venoms pharmacology, DNA, Complementary, Dose-Response Relationship, Drug, Drug Antagonism, Electrophoresis, Polyacrylamide Gel, Lectins, C-Type chemistry, Molecular Sequence Data, Sequence Alignment, Coagulants chemistry, Coagulants pharmacology, Crotalid Venoms chemistry, Lectins, C-Type analysis, Platelet Aggregation drug effects, Trimeresurus physiology
- Abstract
Serious clinical symptoms of Trimeresurus jerdonii bite are mainly caused by abnormalities of blood system. We have previously identified and characterized several bioactive components affecting human blood system, such as serine proteases, metalloproteinases and disintegrins. But few snaclec was characterized in the T. jerdonii venom. In this study, a novel snaclec, named jerdonuxin, was isolated, molecular cloned and characterized as a human platelet agonist. On SDS-polyacrylamide gel electrophoresis, jerdonuxin showed a single band with an apparent molecular weight of 120 kDa under non-reducing conditions and two distinct bands with apparent molecular weights of 18 kDa (α-subunit) and 14 kDa (β-subunit) under reducing conditions. The cDNA sequence of each subunit of jerdonuxin was identified. The precursors of both subunits contain a 23-amino acid residue signal peptide and the mature proteins are composed of 135 and 125 amino acids for α- and β-subunits, respectively. The N-terminal amino acid sequences of each subunit determined by Edman degradation were consistent with deduced amino acid sequences of cDNA. Jerdonuxin dose-dependently induced human platelet aggregation. The phosphorylation profile pattern induced by jerdonuxin showed similar with mucetin (a platelet agonist via glycoprotein Ib), but different from stejnulxin (an agonist via glycoprotein VI). The jerdonuxin-induced platelet aggregation was inhibited by the anti-GPIbα or anti-GPIIb polyclonal antibodies, but not by anti-GPVI polyclonal antibodies. In summary, a novel snaclec of platelet agonist was purified and characterized from the T. jerdonii venom and our data also suggested that GPIb was involved in jerdonuxin-induced platelet aggregation., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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27. Optical waveguides in Nd:GGG crystals produced by H+ or C3+ ion implantation.
- Author
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Ren YY, Chen F, Lu QM, and Ma HJ
- Abstract
The optical waveguides in neodymium-doped gadolinium gallium garnet crystal are fabricated, to our knowledge for the first time, by either H(+) or C(3+) ion implantation. The reconstructed refractive index profiles of the planar waveguides have shown, in both cases, the typical "enhanced well" + "barrier" distributions. The two-dimensional modal profiles of the channel waveguides, obtained by using an end-face coupling arrangement, are in good agreement with the simulated modal distributions. After moderate thermal annealing at 200 degrees C, the propagation loss of the H- and C-ion-implanted channel waveguides are reduced down to approximately 1.5 and approximately 1.6 dB/cm, respectively, which exhibits acceptable guiding qualities for applications on potential integrated laser generation.
- Published
- 2010
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28. [Animal toxins and human disease: from single component to venomics, from biochemical characterization to disease mechanisms, from crude venom utilization to rational drug design].
- Author
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Lu QM, Lai R, and Zhang Y
- Subjects
- Amphibians, Animals, China, Humans, Insecta, Molecular Structure, Snakes, Venoms therapeutic use, Drug Design, Drug Therapy, Venoms chemistry
- Abstract
Many animals produced a diversity of venoms and secretions to adapt the changes of environments through the long history of evolution. The components including a large quantity of specific and highly active peptides and proteins have become good research models for protein structure-function and also served as tools and novel clues for illustration of human disease mechanisms. At the same time, they are rich natural resources for new drug development. Through the valuable venomous animal resources of China, researchers at the Kunming Institute of Zoology, CAS have carried out animal toxin research over 30 years. This paper reviews the main work conducted on snake venoms, amphibian and insect secretions, and the development from single component to venomics, from biochemical characterization to human disease mechanisms, from crude venom to rational drug design along with a short perspective on future studies.
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- 2010
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29. [Qianlie Jiedu capsule combined with rufloxacin for chronic prostatitis: a randomized double-blind controlled clinical trial].
- Author
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Xu JC, Lu QM, Fu LJ, and Chen YP
- Subjects
- Adolescent, Adult, Chronic Disease, Double-Blind Method, Humans, Male, Middle Aged, Young Adult, Drugs, Chinese Herbal therapeutic use, Fluoroquinolones therapeutic use, Phytotherapy, Prostatitis drug therapy
- Abstract
Objective: Few double-blind controlled trials have been reported on Chinese patent medicines for the treatment of chronic prostatitis. The purpose of this study was to investigate the therapeutic efficacy of Qianlie Jiedu Capsule for chronic prostatitis (CP) by the randomized double-blind controlled method., Methods: Eighty CP patients were equally randomized into an experimental and a control group, the former treated with Qianlie Jiedu Capsule + Rufloxacin, and the latter given placebo + Rufloxacin, both for 4 weeks. All the patients were evaluated by NIH-CPSI and EPS examination before and after the medication., Results: After 4-week treatment, the total score of NIH-CPSI and the scores of pain, voiding symptoms and quality of life were significantly decreased in both groups compared with the baseline (P < 0.05), so did the leukocyte count in EPS (P < 0.05). And the experimental group showed significant drops in the above scores as compared with the control (P < 0.05), except in the leukocyte count in EPS (P > 0.05)., Conclusion: Qianlie Jiedu Capsule combined with Rufloxacin is highly effective for CP by relieving pain and voiding symptoms,decreasing the leukocyte count in EPS and improving the life quality of the patients.
- Published
- 2010
30. Purification and characterization of a new L-amino acid oxidase from Daboia russellii siamensis venom.
- Author
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Zhong SR, Jin Y, Wu JB, Jia YH, Xu GL, Wang GC, Xiong YL, and Lu QM
- Subjects
- Amino Acid Sequence, Chromatography, Gel, Electrophoresis, Polyacrylamide Gel, Escherichia coli drug effects, Humans, L-Amino Acid Oxidase chemistry, L-Amino Acid Oxidase pharmacology, Microbial Sensitivity Tests, Molecular Sequence Data, Platelet Aggregation drug effects, Pseudomonas aeruginosa drug effects, Staphylococcus aureus drug effects, Substrate Specificity, L-Amino Acid Oxidase isolation & purification, Viper Venoms enzymology
- Abstract
A new L-amino acid oxidase (designated as DRS-LAAO) was purified from Daboia russellii siamensis venom by ion-exchange, gel filtration and affinity chromatographies. DRS-LAAO is a homodimeric enzyme with a molecular weight of 120.0 kDa as measured by size exclusion chromatography and the monomeric molecular weight of 58.0 kDa as measured by SDS-PAGE under both non-reducing and reducing conditions. The N-terminal amino acid sequence (ADDKNPLEECFREDD) of DRS-LAAO shares high identity with other snake venom L-amino acid oxidases, especially with those isolated from viperid venoms. The enzyme displayed high specificity towards hydrophobic L-amino acids. The best substrate of DRS-LAAO was L-Leu followed by L-Phe and L-Ile, while five substrates--L-Pro, L-Asn, L-Gly, L-Ser and L-Cys were not oxidized. Optimal pH of DRS-LAAO was 8.8. The enzyme showed no hemorrhagic activity even at a dosage of 55.0 microg. DRS-LAAO dose-dependently inhibited platelet aggregation induced by ADP (83.33 microM) and TMVA (55.0 nM) with an IC(50) value of 32.8 microg/ml and 32.3 microg/ml, respectively. The minimum inhibitory concentrations (MICs) of DRS-LAAO against Staphylococci aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922) were 9.0, 144.0 and 288.0 microg/ml, respectively. The minimum bactericidal concentrations (MBCs) of the enzyme for these strains were twice of the MIC values. These results showed that DRS-LAAO had the strongest antimicrobial activity against S. aureus among these three international standard stains. Antibacterial-activities of DRS-LAAO against eight clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates were also tested. The MICs of DRS-LAAO against these isolates ranged from 4.5 to 36.0 microg/ml. And the MBCs of the enzyme against these isolates ranged from 9.0 to 72.0 microg/ml.
- Published
- 2009
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31. Optical channel waveguide in Nd/Ce codoped YAG laser crystal produced by carbon ion implantation.
- Author
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Kong YX, Chen F, Jaque D, Lu QM, and Ma HJ
- Abstract
Optical channel waveguides in Nd/Ce codoped YAG laser crystal have been fabricated by using mask-assisted carbon ion implantation. The measured waveguide mode distributions were in good agreement with the calculated modal profiles, which implies the feasibility of designable devices. After thermal annealing treatment at 260 degrees C for 30 min in air, the propagation loss of the waveguide was reduced down to approximately 2 dB/cm at a wavelength of 632.8 nm. The microluminescence spectra of the waveguides show that the fluorescence properties of both Ce and Nd ions (including the energy transfer between them) are not significantly affected by the waveguide formation processing, which indicates a fairly good potential for further laser actions in a compact device.
- Published
- 2009
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32. Formation and characterization of a near-stoichiometric LiNbO3 waveguide by MeV oxygen implantation.
- Author
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Wang L and Lu QM
- Abstract
We report the fabrication and optical properties of planar and channel waveguides on z-cut near-stoichiometric LiNbO(3) crystal formed by 6.0 MeVO(3+) implantation at a dose of 5x10(14) ions/cm(2). The properties of the planar waveguide are characterized by use of prism coupling and the reflectivity calculation method. It is found that the effective refractive indices of the transverse magnetic modes increase but the transverse electric ones decrease when an appropriate heat annealing treatment is performed. We also find that only transverse magnetic polarized light could be guided in this waveguide effectively, although the dark mode could be detected in both the transverse electric and the transverse magnetic directions.
- Published
- 2009
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33. Annealing effect on mono-mode refractive index enhanced RbTiOPO4 waveguides formed by ion implantation.
- Author
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Wang LL, Wang L, Wang KM, Lu QM, and Ma HJ
- Subjects
- Computer-Aided Design, Equipment Design, Equipment Failure Analysis, Ions, Reproducibility of Results, Rubidium radiation effects, Sensitivity and Specificity, Titanium radiation effects, Optical Devices, Refractometry instrumentation, Rubidium chemistry, Titanium chemistry
- Abstract
We reported on the annealing features of the RbTiOPO4 planar waveguides fabricated by 6.0 MeV C3+ ion implantation. The thermal stability of the ion-implanted RbTiOPO4 waveguide was investigated by annealing at different temperatures ranging from 260 degrees C to 650 degrees C. Results revealed that when temperatures are higher than 550 degrees C, annealing caused the refractive indices of both ny and nz a saturation behavior. An increase of the ny refractive index in waveguide region was observed after proper annealing. The low loss planar mono-mode waveguides have been achieved in RbTiOPO4 crystals by applying appropriate ion implantation and annealing conditions.
- Published
- 2009
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34. Optical waveguide in stoichiometric lithium niobate formed by 500 keV proton implantation.
- Author
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Wang L, Wang KM, Chen F, Wang XL, Wang LL, Liu H, and Lu QM
- Abstract
We report on the fabrication of planar waveguide in stoichiometric lithium niobate by 500 keV proton implantation with a dose of 1x10(17) ions/cm(2). The formation of n(e) enhancement planar waveguide in the crystal was disclosed by the dark mode spectra and the subsequent endface coupling measurement. The absorption spectra show that the postannealing treatments above 400 masculineC temperature can remove the color centers induced by implantation efficiently. The propagation loss and near-field profiles of the planar waveguide were obtained with an end-face coupling system.
- Published
- 2007
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35. Determination of trace alpha-fetoprotein variant by affinity adsorption solid substrate-room temperature phosphorimetry and its application to the forecast of human diseases.
- Author
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Liu JM, Liu ZB, Lu QM, Li FM, Hu SR, Zhu GH, Huang XM, Li ZM, and Shi XM
- Subjects
- Adsorption, Genetic Variation, Humans, Predictive Value of Tests, Sensitivity and Specificity, Temperature, alpha-Fetoproteins genetics, Diagnostic Tests, Routine, Luminescent Measurements methods, Serum chemistry, alpha-Fetoproteins analysis
- Abstract
In the presence of ion perturber LiAc, 4-generation polyamidoamine dendrimers (4G-D) could emit strong and stable room temperature phosphorescence (RTP) signal at lambda(max)(ex)/lambda(max)(em) = 511.8/675.3 nm on nitrocellulose membrane (NCM), and Triton X-100 could sharply enhance the RTP signal of 4G-D. Triton X-100-4G-D was used to label concanavalin agglutinin (Con A) to get the labeling product Triton X-100-4G-D-Con A. Quantitative specific affinity adsorption (AA) reaction between Triton X-100-4G-D-Con A and alpha-fetoprotein variant (AFP-V) could be carried out on the surface of NCM, whose product Triton X-100-4G-D-Con A-AFP-V could emit strong and stable RTP and its deltaI(p) was proportional to the content of AFP-V. According to the facts above, a new affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) for the determination of trace AFP-V by Con A labeled with Triton X-100-4G-D was established. Detection limits of this method were 0.23 fg spot(-1) (direct method, corresponding concentration: 5.8x10(-13) g mL(-1)) and 0.13 fg spot(-1) (sandwich method, corresponding concentration: 3.2x10(-13) g mL(-1)). It has been successfully applied to determine the content of AFP-V in human serum and forecast human diseases, for its high sensitivity, long RTP lifetime, good repeatability, high accuracy and little background perturbation with lambda(max)(em) at the long wavelength area. Meanwhile, the mechanism for the determination of trace AFP-V using AA-SS-RTP was also discussed.
- Published
- 2007
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36. Resonance Rayleigh scattering spectral method for the determination of raloxifene using gold nanoparticle as a probe.
- Author
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Liu SP, He YQ, Liu ZF, Kong L, and Lu QM
- Subjects
- Sensitivity and Specificity, Gold chemistry, Metal Nanoparticles chemistry, Raloxifene Hydrochloride analysis, Scattering, Radiation, Spectrum Analysis methods
- Abstract
When gold nanoparticles were being prepared by sodium citrate reduction method, citrate anions self-assembled on the surface of gold nanoparticles to form supermolecular complex anions with negative charges, and protonated raloxifene (Ralo) was positively charged and could bind with the complex anions to form larger aggregates through electrostatic force and hydrophobic effects, which could result in the remarkable enhancement of the resonance Rayleigh scattering intensity (RRS), and the appearance of new RRS spectra. At the same time, the second-order scattering (SOS) and frequency-doubling scattering (FDS) intensities were also enhanced. The maximum wavelengths were located near 370 nm for RRS, 520 nm for SOS, and 350 nm for FDS, respectively. Among them, the RRS method had the highest sensitivity and the detection limit was 5.60 ng mL(-1) for Ralo, and its linear range was 0.05-2.37 microg mL(-1). A new RRS method for the determination of trace Ralo using gold nanoparticles probe was developed. The optimum conditions of the reaction and influencing factors were investigated. In addition, the reaction mechanism and the reasons for the enhancement of RRS were discussed.
- Published
- 2007
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37. Downregulation of survivin by RNAi inhibits growth of human gastric carcinoma cells.
- Author
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Miao GY, Lu QM, and Zhang XL
- Subjects
- Apoptosis drug effects, Carcinoma pathology, Cell Cycle drug effects, Cell Line, Tumor, Down-Regulation drug effects, Humans, Inhibitor of Apoptosis Proteins, Microtubule-Associated Proteins genetics, Neoplasm Proteins genetics, Stomach Neoplasms pathology, Survivin, Carcinoma metabolism, Cell Proliferation drug effects, Microtubule-Associated Proteins metabolism, Neoplasm Proteins metabolism, RNA, Small Interfering pharmacology, Stomach Neoplasms metabolism
- Abstract
Aim: To investigate the inhibitory effect of a specific small survivin interfering RNA (siRNA) on cell proliferation and the expression of survivin in human gastric carcinoma cell line SGC-7901., Methods: To knockdown survivin expression, a small interfering RNA targeting against survivin was synthesized and transfected into SGC-7901 cells with lipofectamine 2000. The downregulation of survivin expression at both mRNA and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Cell proliferation inhibition rates were determined by methyl thiazolyl tetrazolium (MTT) assay. The effect of survivin siRNA on cell cycle distribution and cell apoptosis was determined by flow cytometry (FCM)., Results: RNA interference could efficiently suppress the survivin expression in SGC-7901 cells. At 48 h after transfection, the expression inhibition rate was 44.52% at mRNA level detected by RT-PCR and 40.17% at protein level by Western blot analysis. Downregulation of survivin resulted in significant inhibition of tumor cell growth in vitro. The cell proliferation inhibition rates at 24, 48 and 72 h after survivin siRNA and non-silencing siRNA transfection, were 34.06%, 47.61% and 40.36%, respectively. The apoptosis rate was 3.56% and the number of cells was increased in G(0)/G(1) phase from 38.2% to 88.6%, and decreased in S and G(2)/M phase at 48 h after transfection., Conclusion: Downregulation of survivin results in significant inhibition of tumor growth in vitro. The inhibition of survivin expression can induce apoptosis of SGC-7901 cells. The use of survivin siRNA deserves further investigation as a novel approach to cancer therapy.
- Published
- 2007
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38. Solid-substrate room-temperature phosphorescence immunoassay based on an antibody labeled with nanoparticles containing dibromofluorescein luminescent molecules and analytical application.
- Author
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Liu JM, Lu QM, Wang Y, Xu SS, Lin XM, Li LD, and Lin SQ
- Subjects
- Animals, Antibodies immunology, Bromine chemistry, Goats, Humans, Immunoassay methods, Immunoglobulin G blood, Immunoglobulin G immunology, Membranes, Artificial, Nylons chemistry, Particle Size, Silicates chemistry, Silicon Dioxide chemistry, Antibodies chemistry, Fluoresceins chemistry, Immunoglobulin G analysis, Luminescent Measurements methods, Nanostructures chemistry
- Abstract
Luminescent 20-nm silicon dioxide nanoparticles containing dibromofluorescein (D; particles denoted D-SiO(2)) were synthesized by the sol-gel method. In the presence of Pb(Ac)(2) as a heavy atom perturber, the particle can emit the intense and stable room temperature phosphorescence(RTP) signal on a polyamide membrane at the wavelength of lambdaex(max)/lambdaem(max) = 460/623 nm for D. Our research indicates that the specific immune reaction between goat-anti-human IgG antibody labeled with D-SiO(2) and human IgG can be carried out quantitatively on a polyamide membrane, and the phosphorescence intensity was evidently enhanced after the immunoreaction. Thus a new solid substrate-room temperature phosphorescence immunoassay (SS-RTP-IA) for determination of human IgG was established. The linear range of this method is 0.0624-20.0 pg spot(-1) of human IgG (corresponding to a concentration range of 0.156-50.0 ng ml(-1), sample volume: 0.40 microl spot(-1)). The regression equation of the working curve is DeltaIp = 94.39 + 17.00 m IgG (pg spot(-1)) (460/623 nm, r = 0.9998). Detection limit calculated as 3 Sb/k is 0.015 pg spot(-1). After elevenfold replicate measurement, RSD are 3.2% and 2.4% for samples containing 0.156 and 50.0 ng l(-1) IgG, respectively. This method is sensitive, accurate, and of high precision. And it has been applied to the determination of IgG in human serum with satisfactory results. Meanwhile, the mechanism of SS-RTP-IA based on an antibody labeled with nanoparticles containing dibromofluorescein luminescent molecules was discussed.
- Published
- 2005
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39. Molecular characterization of a weak fibrinogen-clotting enzyme from Trimeresurus jerdonii venom.
- Author
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Jin Y, Lu QM, Chen RQ, Wu JB, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Molecular Sequence Data, Sequence Alignment, Sequence Homology, Amino Acid, Serine Endopeptidases isolation & purification, Serine Endopeptidases metabolism, Substrate Specificity, Trimeresurus, Blood Coagulation drug effects, Crotalid Venoms enzymology, Fibrinogen chemistry, Serine Endopeptidases chemistry
- Abstract
A fibrinogen-clotting enzyme designed as jerdonobin-II was isolated from the venom of Trimeresurus jerdonii. It differed in molecular weight and N-terminal sequence with the previously isolated jerdonobin, a thrombin-like enzyme from the same venom. The enzyme consists of a single polypeptide chain with molecular weights of 30,000 and 32,000 under non-reducing and reducing conditions, respectively. Jerdonobin-II showed weak fibrinogen clotting activity and its activity unit on fibrinogen was calculated to be less than one unit using human thrombin as standard. The precursor protein sequence of jerodonobin-II was deduced from cloned cDNA sequence. The sequence shows high similarity (identity=89%) to TSV-PA, a specific plasminogen activator from venom of T. stejnegeri. Despite of the sequence similarity, jerdonobin-II was found devoid of plasminogen activating effect. Sequence alignment analysis suggested that the replacement of Lys239 in TSV-PA to Gln239 in jerdonobin-II might play an important role on their plasminogen activating activity difference.
- Published
- 2005
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40. A novel disintegrin, jerdonatin, inhibits platelet aggregation and sperm-egg binding.
- Author
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Zhou XD, Ding CH, Tai H, Jin Y, Chen RQ, Lu QM, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cloning, Molecular, Crotalid Venoms chemistry, Crotalid Venoms pharmacology, DNA, Complementary genetics, Disintegrins chemistry, Disintegrins genetics, Disintegrins isolation & purification, Female, Humans, Male, Mice, Molecular Sequence Data, Molecular Weight, Ovum drug effects, Ovum metabolism, Sequence Analysis, Spermatozoa drug effects, Spermatozoa metabolism, Disintegrins pharmacology, Platelet Aggregation drug effects, Sperm-Ovum Interactions drug effects
- Abstract
A novel disintegrin, jerdonatin, was purified to homogeneity from Trimeresurus jerdonii venom by gel filtration and reversed-phase high-pressure liquid chromatography. We isolated the cDNA encoding jerdonatin from the snake venom gland. Jerdonatin cDNA precursor encoded pre-peptide, metalloprotease and disintegrin domain. Jerdonatin is composed of 72 amino acid residues including 12 cysteines and the tripeptide sequence Arg-Gly-Asp (RGD), a well-known characteristic of the disintegrin family. Molecular mass of jerdonatin was determined to be 8011 Da by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Jerdonatin inhibited ADP- and collagen-induced human platelet aggregation with IC50 of 123 and 135 nM, respectively. We also investigated the effect of jerdonatin on the binding of B6D2F1 hybrid mice spermatozoa to mice zona-free eggs and their subsequent fusion. Jerdonatin significantly inhibited sperm-egg binding in a concentration-dependent manner, but had no effect on the fusion of sperm-egg. These results indicate that integrins on the egg play a role in mammalian fertilization.
- Published
- 2004
- Full Text
- View/download PDF
41. A novel high molecular weight metalloproteinase cleaves fragment F1 of activated human prothrombin.
- Author
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Chen RQ, Jin Y, Wu JB, Zhou XD, Li DS, Lu QM, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Chromatography, Gel, Chromatography, Ion Exchange, Edetic Acid metabolism, Electrophoresis, Polyacrylamide Gel, Fibrinogen metabolism, Hemorrhage chemically induced, Humans, Insulin metabolism, Metalloproteases antagonists & inhibitors, Mice, Molecular Sequence Data, Sequence Alignment, Sequence Analysis, Protein, Crotalid Venoms metabolism, Metalloproteases metabolism, Peptide Fragments metabolism, Prothrombin metabolism, Trimeresurus
- Abstract
A hemorrhagic proteinase, jerdohagin, was purified from Trimeresurus jerdonii venom by gel filtration and ion-exchange chromatographies. It was a single chain polypeptide with an apparent molecular weight of 96 kDa as estimated by SDS-PAGE under the non-reducing and reducing conditions. Internal peptide sequencing indicated that it consisted of metalloproteinase, disintegrin-like and cysteine-rich domains and belonged to the class III snake venom metalloproteinases (class P-III SVMPs). Like other typical metalloproteinases, hemorrhagic activities of jerdohagin were completely inhibited by EDTA, but not by PMSF. Jerdohagin preferentially degraded alpha-chain of human fibrinogen. Interestingly, jerdohagin did not activate human prothrombin, whereas it cleaved human prothrombin and fragment F1 of activated human prothrombin.
- Published
- 2004
- Full Text
- View/download PDF
42. Purification, characterization and primary structure of a chymotrypsin inhibitor from Naja atra venom.
- Author
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Zhou XD, Jin Y, Lu QM, Li DS, Zhu SW, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Chromatography, Liquid, Chymotrypsin chemistry, Elapidae, Molecular Sequence Data, Sequence Alignment, Sequence Analysis, Protein, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Elapid Venoms chemistry, Trypsin Inhibitors chemistry, Trypsin Inhibitors isolation & purification
- Abstract
A chymotrypsin inhibitor, designated NA-CI, was isolated from the venom of the Chinese cobra Naja atra by three-step chromatography. It inhibited bovine alpha-chymotrypsin with a Ki of 25 nM. The molecular mass of NA-CI was determined to be 6403.8 Da by matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) analysis. The complete amino acid sequence was determined after digestion of S-carboxymethylated inhibitor with Staphylococcus aureus V8 protease and porcine trypsin. NA-CI was a single polypeptide chain composed of 57 amino acid residues. The main contact site with the protease (P1) has a Phe, showing the specificity of the inhibitor. NA-CI shared great similarity with the chymotrypsin inhibitor from Naja naja venom (identities=89.5%) and other snake venom protease inhibitors.
- Published
- 2004
- Full Text
- View/download PDF
43. Purification, cloning and biological characterization of a novel disintegrin from Trimeresurus jerdonii venom.
- Author
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Zhou XD, Jin Y, Chen RQ, Lu QM, Wu JB, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Antineoplastic Agents pharmacology, Base Sequence, Chromatography, High Pressure Liquid, Cloning, Molecular, Crotalid Venoms genetics, Crotalid Venoms isolation & purification, Crotalid Venoms pharmacology, DNA, Complementary genetics, Disintegrins chemistry, Disintegrins genetics, Disintegrins pharmacology, Mice, Mice, Inbred C57BL, Molecular Sequence Data, Oligopeptides genetics, Oligopeptides pharmacology, Sequence Homology, Survival Rate, Antineoplastic Agents isolation & purification, Crotalid Venoms chemistry, Disintegrins isolation & purification, Melanoma, Experimental drug therapy, Oligopeptides isolation & purification, Trimeresurus
- Abstract
A novel disintegrin, jerdonin, was purified from the Trimeresurus jerdonii venom by means of gel filtration and reverse phase high pressure liquid chromatography. Its coding cDNA was also isolated from the venom gland. The jerdonin coding cDNA is part of a precursor composed of proprotein, metalloproteinase, and disintegrin domains. From the deduced amino acid sequence, jerdonin is composed of 71 amino acid residues including 12 cysteines and the tripeptide sequence Arg-Gly-Asp (RGD), a well-known characteristic of the disintegrin family. Molecular mass of jerdonin was determined to be 7483Da by matrix-assisted laser desorption ionization time of flight mass spectrometry. Jerdonin inhibited ADP- and collagen-induced human platelet aggregation with IC(50) of 220 and 240 nM, respectively. In vivo, jerdonin inhibited the growth of subcutaneously inoculated B16 solid tumor in C57BL/6 mice and improved the survival time of the tumor-bearing mice.
- Published
- 2004
- Full Text
- View/download PDF
44. A new protein structure of P-II class snake venom metalloproteinases: it comprises metalloproteinase and disintegrin domains.
- Author
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Chen RQ, Jin Y, Wu JB, Zhou XD, Lu QM, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Chromatography, Gel, DNA, Complementary, Disintegrins genetics, Disintegrins isolation & purification, Electrophoresis, Polyacrylamide Gel, Metalloproteases genetics, Metalloproteases isolation & purification, Molecular Sequence Data, Phylogeny, Sequence Homology, Amino Acid, Trimeresurus, Crotalid Venoms enzymology, Disintegrins chemistry, Metalloproteases chemistry
- Abstract
A new metalloproteinase-disintegrin, named Jerdonitin, was purified from Trimeresurus jerdonii venom with a molecular weight of 36 kDa on SDS-PAGE. It dose-dependently inhibited ADP-induced human platelet aggregation with IC(50) of 120nM. cDNA cloning and sequencing revealed that Jerdonitin belonged to the class II of snake venom metalloproteinases (SVMPs) (P-II class). Different from other P-II class SVMPs, metalloproteinase and disintegrin domains of its natural protein were not separated, confirmed by internal peptide sequencing. Compared to other P-II class SVMPs, Jerdonitin has two additional cysteines (Cys219 and Cys238) located in the spacer domain and disintegrin domain, respectively. They probably form a disulfide bond and therefore the metalloproteinase and disintegrin domains cannot be separated by posttranslationally processing. In summary, comparison of the amino acid sequences of Jerdonitin with those of other P-II class SVMPs by sequence alignment and phylogenetic analysis, in conjunction with natural protein structure data, suggested that it was a new type of P-II class SVMPs.
- Published
- 2003
- Full Text
- View/download PDF
45. Stejnulxin, a novel snake C-type lectin-like protein from Trimeresurus stejnegeri venom is a potent platelet agonist acting specifically via GPVI.
- Author
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Lee WH, Du XY, Lu QM, Clemetson KJ, and Zhang Y
- Subjects
- Amino Acid Sequence, Animals, Cloning, Molecular, Crotalid Venoms isolation & purification, Humans, Lectins, C-Type isolation & purification, Lectins, C-Type metabolism, Molecular Sequence Data, Phosphorylation, Platelet Glycoprotein GPIIb-IIIa Complex metabolism, Sequence Analysis, Protein, Viper Venoms isolation & purification, Viper Venoms metabolism, Viper Venoms pharmacology, Crotalid Venoms pharmacology, Platelet Activation drug effects, Platelet Membrane Glycoproteins metabolism
- Abstract
Stejnulxin, a novel snake C-type lectin-like protein with potent platelet activating activity, was purified and characterized from Trimeresurus stejnegeri venom. Under non-reducing conditions, it migrated on a SDS-polyacrylamide gel with an apparent molecular mass of 120 kDa. On reduction, it separated into three polypeptide subunits with apparent molecular masses of 16 kDa (alpha), 20 kDa (beta1) and 22 kDa (beta2), respectively. The complete amino acid sequences of its subunits were deduced from cloned cDNAs. The N-terminal sequencing and cDNA cloning indicated that beta1 and beta2 subunits of stejnulxin have identical amino acid sequences and each contains two N-glycosylation sites. Accordingly, the molecular mass difference between beta1 and beta2 is caused by glycosylation heterogenity. The subunit amino acid sequences of stejnulxin are similar to those of convulxin, with sequence identities of 52.6% and 66.4% for the alpha and beta, respectively. Stejnulxin induced human platelet aggregation in a dose-dependent manner. Antibodies against alphaIIbbeta3 inhibited the aggregation response to stejnulxin, indicating that activation of alphaIIbbeta3 and binding of fibrinogen are involved in stejnulxin-induced platelet aggregation. Antibodies against GPIbalpha or alpha2beta1 as well as echicetin or rhodocetin had no significant effect on stejnulxin-induced platelet aggregation. However, platelet activation induced by stejnulxin was blocked by anti-GPVI antibodies. In addition, stejnulxin induced a tyrosine phosphorylation profile in platelets that resembled that produced by convulxin. Biotinylated stejnulxin bound specifically to platelet membrane GPVI.
- Published
- 2003
- Full Text
- View/download PDF
46. Purification, characterization and biological activity of an L-amino acid oxidase from Trimeresurus mucrosquamatus venom.
- Author
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Wei JF, Wei Q, Lu QM, Tai H, Jin Y, Wang WY, and Xiong YL
- Subjects
- Amino Acid Oxidoreductases chemistry, Amino Acid Oxidoreductases isolation & purification, Amino Acid Sequence, Animals, Bacteria drug effects, Bacteria growth & development, Cell Line, Transformed, Cell Survival drug effects, Chromatography, Ion Exchange, Dose-Response Relationship, Drug, Edema chemically induced, Electrophoresis, Polyacrylamide Gel, Humans, L-Amino Acid Oxidase, Mice, Molecular Sequence Data, Molecular Weight, Platelet Aggregation drug effects, Rabbits, Sequence Analysis, Protein, Sequence Homology, Amino Acid, Amino Acid Oxidoreductases pharmacology, Crotalid Venoms enzymology
- Abstract
An L-amino acid oxidase (TM-LAO) from the venom of Hunan Trimeresurus mucrosquamatus was purified to homogeneity by three steps including DEAE Sephadex A-50 ion-exchange chromatography, Sephadex G-75 gel filtration and Resource Q ion-exchange chromatography. TM-LAO is composed of two identical subunits with a molecular weight of 55 kD by SDS-polyacrylamide gel electrophoresis. The molecular weight was different with that of LAO purified from the same species distributed in Taiwan that was 70 kD. The 24 N-terminal amino acid sequence of TM-LAO is ADNKNPLEECFRETNYEEFLEIAR, which shares high similarity with other Viperid snake venom LAOs and has moderate similarity with Elapid snake venom LAOs. Further studies found that TM-LAO inhibited the growth of E. coli, S. aurues and B. dysenteriae. TM-LAO also showed cytotoxicity and platelet aggregation activity. All the biological activities were eliminated by catalase, a H(2)O(2) scavenger. It was shown that these biological effects were possibly due to the formation of H(2)O(2) produced by TM-LAO.
- Published
- 2003
47. [Factors influencing the development of portal hypertensive gastropathy with liver fibrosis in schistosomiasis].
- Author
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Lou YY, Wu WL, and Lu QM
- Subjects
- Aged, Aged, 80 and over, Esophageal and Gastric Varices complications, Esophageal and Gastric Varices therapy, Female, Humans, Liver Cirrhosis parasitology, Male, Middle Aged, Retrospective Studies, Sclerotherapy adverse effects, Splenectomy adverse effects, Hypertension, Portal etiology, Liver Cirrhosis complications, Schistosomiasis japonica complications, Stomach Diseases etiology
- Abstract
Objective: To evaluate the factors influencing the development of portal hypertensive gastropathy (PHG) with liver fibrosis in schistosomiasis japonica., Methods: A retrospective study was executed on 196 hospitalized patients with schistosomiasis liver fibrosis (109 of them complicated with PHG) from 1998 to 2002. Endoscopic examinations were carried out for all the cases. The analysis was made with a comparison of the PHG incidence to the degree of esophageal varices and the degree of liver function according to Child Pugh's scores., Results: With slight, moderate and severe degree of esophageal varices, the PHG incidence was 47.7%, 54.8%, and 59.1% respectively (P > 0.05). With the Child pugh's classes of A, B and C, the PHG incidence was 56.0%, 53.3%, and 63.6% respectively (P > 0.05). With no surgical intervention, it was 51.3%, and with splenectomy, only 50.0%. With splenectomy plus an operation of transection and an endoscopic sclerotherapy, it was 70.6% and 85.0%. The PHG incidence was significantly higher in the group of splenectomy plus operation of transection and the group with endoscopic sclerotherapy than the group with no surgical intervention (P < 0.05)., Conclusion: The PHG incidence in schistosomiasis liver fibrosis has no relationship with the degree of esophageal varices and Child Pugh classes of liver function. However, splenectomy plus transection and endoscopic sclerotherapy may accelerate the PHG development.
- Published
- 2003
48. L-amino acid oxidase from Trimeresurus jerdonii snake venom: purification, characterization, platelet aggregation-inducing and antibacterial effects.
- Author
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Lu QM, Wei Q, Jin Y, Wei JF, Wang WY, and Xiong YL
- Subjects
- Amino Acid Oxidoreductases chemistry, Amino Acid Oxidoreductases pharmacology, Amino Acid Sequence, Animals, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, L-Amino Acid Oxidase, Molecular Sequence Data, Platelet Aggregation drug effects, Rabbits, Sequence Homology, Amino Acid, Amino Acid Oxidoreductases isolation & purification, Anti-Bacterial Agents isolation & purification, Crotalid Venoms enzymology, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects
- Abstract
An L-amino acid oxidase (LAO), designated as TJ-LAO, was purified to homogeneity from the venom of Trimeresurus jerdonii by Sephadex G-100 and Q Sepharose HP chromatography. The molecular weight of this enzyme was 110 kD as estimated by analytical gel filtration and was 55 kD by SDS-polyacrylamide gel electrophoresis, suggesting that the enzyme is composed of two subunits. The enzyme has an absorption spectrum characteristic of flavoproteins, containing 2 moles of FMN per mole of enzyme. The N-terminal sequence of TJ-LAO shares high homology with other viperid snake venom LAOs. Homology with elapid venom LAO is lower. TJ-LAO inhibited the growth of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus megaterium. The antibacterial effect associated with LAO activity was elminated with the addition of catalase. Platelets in platelet-rich plasma aggregated upon the addition of TJ-LAO. The enzyme-induced aggregation was inhibited by catalase, suggesting formation of H2O2 was essential for TJ-LAO to induce platelet aggregation. These results showed H2O2 formation is important for the biological effects of LAO.
- Published
- 2002
49. Purification and characterization of alpha-mucrofibrase, a novel serine protease with alpha-fibrinogenase activity from the venom of Chinese Habu (Trimeresurus mucrosquamatus).
- Author
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Wei Q, Jin Y, Lu QM, Wei JF, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Chromatography, DEAE-Cellulose, Chromatography, Ion Exchange, Crotalid Venoms chemistry, Crotalid Venoms metabolism, Enzyme Stability, Fibrinogen metabolism, Hemorrhage chemically induced, Metalloendopeptidases chemistry, Metalloendopeptidases metabolism, Mice, Molecular Sequence Data, Platelet Aggregation drug effects, Rabbits, Sequence Homology, Amino Acid, Serine Endopeptidases chemistry, Serine Endopeptidases metabolism, Serine Proteinase Inhibitors pharmacology, Substrate Specificity, Crotalid Venoms enzymology, Crotalid Venoms isolation & purification, Metalloendopeptidases isolation & purification, Serine Endopeptidases isolation & purification, Trimeresurus
- Abstract
A novel fibrinogenolytic protease, named alpha-mucrofibrase, was purified from the venom of Chinese Habu (Trimeresurus mucrosquamatus) by DEAE-Sephadex A-50 ion-exchange chromatography and Sephadex G-100 (super fine) gel filtration alpha-Mucrofibrase is a single-chain polypeptide of approximately 29 kDa. It is stable even at 95 degrees C, and the most susceptible hydrolysis substrate is S-2302. It cleaved primarily the Aalpha chain of fibrinogen followed by the Bbeta chain, while the gamma chain was partially affected. N-terminal sequence of this fibrinogenolytic enzyme has great homology with those of other snake venom serine proteases. The esterase activity of alpha-mucrofibrase is inhibited by phenylmethylsulfonyl fluoride (PMSF) but not by metal chelator (EDTA), suggesting this fibrinogenase belongs to the venom serine protease family.
- Published
- 2002
50. Purification and cloning of a novel C-type lectin-like protein with platelet aggregation activity from Trimeresurus mucrosquamatus venom.
- Author
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Wei Q, Lu QM, Jin Y, Li R, Wei JF, Wang WY, and Xiong YL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Blood Platelets drug effects, Cloning, Molecular, Crotalid Venoms genetics, DNA, Complementary genetics, Dose-Response Relationship, Drug, Electrophoresis, Polyacrylamide Gel, Mass Spectrometry, Molecular Sequence Data, Sequence Analysis, Protein, Viper Venoms pharmacology, Crotalid Venoms chemistry, Lectins, C-Type genetics, Lectins, C-Type isolation & purification, Platelet Aggregation, Trimeresurus, Viper Venoms genetics, Viper Venoms isolation & purification
- Abstract
TMVA, a novel C-type lectin-like protein that induces platelet aggregation in a dose-dependent manner, was purified from the venom of Trimeresurus mucrosquamatus. It consists of two subunits, alpha (15536 Da) and beta (14873 Da). The mature amino acid sequences of the alpha (135 amino acids) and beta subunits (123 amino acids) were deduced from cloned cDNAs. Both of the sequences show great similarity to C-type lectin-like venom proteins, including a carbohydrate recognition domain. The cysteine residues of TMVA are conserved at positions corresponding to those of flavocetin-A and convulxin, including the additional Cys135 in the alpha subunit and Cys3 in the beta subunit. SDS-PAGE, mass spectrometry analysis and amino acid sequence showed that native TMVA exists as two convertible multimers of (alpha beta)(2) and (alpha beta)(4) with molecular weights of 63680 and 128518 Da, respectively. The (alpha beta)(2) complex is stabilized by an interchain disulfide bridge between the two alpha beta-heterodimers, whereas the stabilization of the (alpha beta)(4) complex seems to involve non-covalent interactions between the (alpha beta)(2) complexes.
- Published
- 2002
- Full Text
- View/download PDF
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