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Find video protocols related to scientific articles indexed in Pubmed.
Kinetic and equilibrium studies of bile salt-liposome interactions.
J Liposome Res
PUBLISHED: 06-25-2014
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Abstract Research has suggested that exposure to sub-micellar concentrations of bile salts (BS) increases the permeability of lipid bilayers in a time-dependent manner. In this study, incubation of soy phosphatidylcholine small unilamellar vesicles (liposomes) with sub-micellar concentrations of cholate (C), deoxycholate (DC), 12-monoketocholate (MKC) or taurocholate (TC) in pH 7.2 buffer increased membrane fluidity and negative zeta potential in the order of increasing BS liposome-pH 7.2 buffer distribution coefficients (MKC?
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Quantitative analysis of glycerol levels in human urine by liquid chromatography-tandem mass spectrometry.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 02-12-2014
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Glycerol has the latent capacity to act as a plasma volume expander and disguise blood doping practices. Therefore, it has been prohibited in sports as a masking agent by the World Anti-Doping Agency (WADA) since January 2010 and a urinary threshold (1mg/mL) was recommended recently [1]. The purpose of this study was to establish and validate a novel quantitative method for the determination of urinary glycerol concentrations using a liquid chromatography-tandem mass spectrometry approach. This simple yet highly specific method made use of the derivatization of glycerol by benzoyl chloride in aqueous solution at 40°C followed by analysis via LC-ESI-MS/MS without sample pre-concentration or cleanup. The assay was linear over the concentration range of 1.0-1000?g/mL for glycerol in human urine. The lower limit of detection (LLOD) and lower limit of quantitation (LLOQ) were 0.3?g/mL and 1.0?g/mL, respectively. The intra- and inter-day precision of the method at three concentration levels (3, 500 and 900?g/mL) was less than 12.2%. The method also afforded satisfactory results in terms of accuracy, derivatization yield, extraction recovery, matrix effect and specificity. The method has been successfully applied to the detection of glycerol in "Quality Assurance Program" samples provided by the World Association of Anti-Doping Scientists (WAADS) and routine doping-control samples in our laboratory.
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Effects of metaphyseal bone tumor removal with preservation of the epiphysis and knee arthroplasty.
Exp Ther Med
PUBLISHED: 01-17-2014
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In this study, the effects of surgical removal of malignant metaphyseal bone tumors with epiphysis preservation and knee arthroplasty were analyzed. A total of 15 patients with malignant metaphyseal bone tumors were investigated. Six of these patients underwent epiphyseal preservation surgery with preoperative physeal distraction, termed the physeal distraction (PD) group. Nine patients underwent resection of the knee joint, combined with metal prosthesis transfer, termed the knee arthroplasty (KA) group. Tumor control, limb length discrepancy, range of movement (ROM) of the knee and functional outcome of lower limb [Musculoskeletal Tumor Society (MSTS) score and the Toronto extremity salvage score (TESS)] were assessed for these two groups. All 15 patients were followed-up after the surgery. One patient in the PD group was found to have lung tumor metastasis; however, no local tumor recurrence was found. In the KA group, local tumor recurrence was found in one patient, and lung metastases were observed in two cases postoperatively. The limb length discrepancy in patients of the PD group was 2.58±0.27 cm, which was significantly less compared with that in patients in the KA group (4.01±0.13 cm; P<0.05). In addition, the lower limb knee ROM in patients in the PD group was 127.70±14.63°, which was increased compared to that in patients in the KA group (105.70±15.48°; P<0.05). The mean MSTS score was 86.67% with a mean TESS of 82.33% in patients from the PD group, which showed no significant difference compared with the respective scores for patients in the KA group (P>0.05). Therefore, epiphyseal sparing limb-saving surgeries should be considered for the treatment of malignant metaphyseal bone tumors in children, when certain indications are satisfied.
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[Tumor necrosis factro-? and NF-?B play a role in macrophage-like THP-1 cells promoting coal tar pitch extract-induced tumorigenic transformation of human bronchial epithelial cells].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 01-17-2014
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To characterize the role of tumor necrosis factro-? (TNF-?) and NF-?B play a role in macrophage-like THP-1 cells promoting coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells (BEAS-2B).
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Quantitative assessment of lung cancer associated with genes methylation in the peripheral blood.
Exp. Lung Res.
PUBLISHED: 04-24-2013
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Lung cancer is the leading cause of cancer-related deaths worldwide due mainly to late diagnosis and poor prognosis. Aberrant promoter methylation is an important mechanism for silencing of tumor suppressor genes during carcinogenesis and a promising tool for the development of molecular biomarkers.
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Development and in vitro characterizations of bifendate nanosuspensions.
J Biomed Nanotechnol
PUBLISHED: 12-27-2011
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It is reported that nano-sizing is one of the promising methods for improving the dissolution rate and oral bioavailability of poorly water-soluble drugs. In this study, bifendate (DDB) suspensions have been successfully produced by employing two different techniques, the precipitation-ultrasonication method and the precipitation-combined microfluidization method. According to the preliminary test, in the precipitation-ultrasonication process, the concentrations of polyvinylpyrrolidone K30 (PVPK30) and lecithin in the anti-solvent, the concentration of DDB in the organic phase and the precipitation temperature were optimized at 0.05%, 0.2%, 40 mg/ml and 0-3 degrees C, respectively. In the microfluidization process, two important parameters, the number of cycles and the pressure were investigated systematically and 10 cycles at 23,300 psi of homogenization pressure was found to be the most efficient method. Comparing the two kinds of suspensions by TEM and particle size analysis, a small and uniform size with narrow distribution was achieved by the precipitation-combined microfluidization process. Both formulations before and after particle size reduction were characterized by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The DSC and XRD testified that there was no crystalline state changed in the size reduction process. In the in vitro dissolution test, an enhanced dissolution property was shown due to the increased surface area. Besides, lyophilization of DDB nanosuspensions was an effective measure to stabilize the systems for long time.
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Extracellular Matrix Protein Mindin is Required for the Complete Allergic Response to Fungal-Associated Proteinase.
J Allergy Ther
PUBLISHED: 09-20-2011
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Asthma remains an important cause of morbidity and mortality with an incidence that continues to rise. Despite the importance of this disease, the mechanisms by which the host develops allergic airways disease remain poorly understood. The development of allergic airways disease appears to be contingent on activation of both the innate and adaptive immune system, but little is known about the cross-talk between these two systems. The extracellular matrix protein mindin (Spondin 2) has been previously demonstrated to have functional roles in both the innate and adaptive immunological responses. Previous work supports that pulmonary challenge with fungal-associated allergenic proteinase (FAP) induces an innate allergic response. We hypothesized that mindin would modify the biological response to FAP. Saline or FAP was administered by oropharyngeal aspiration to C57BL/6 wild type or mindin-null mice every 4 days for a total of five exposures. FAP exposed C57BL/6 mice developed enhanced airway hyperresponsiveness (AHR) to methacholine challenge and increased neutrophils and eosinophils in the bronchoalveolar lavage as compared to saline exposed controls. These responses were significantly reduced in mindin-null mice exposed to FAP. FAP challenge was associated with a broad induction of cytokines (IL-1?, TNF?, Th1, Th2, and IL-17), chemokines, and growth factors, which were reduced in mindin-null mice exposed to FAP. RNA expression in lung monocytes for representative M1 and M2 activation markers were increased by FAP, but were independent of mindin. Our observations support that challenge with FAP results in activation of both innate and adaptive immune signaling pathways in a manner partially dependent on mindin. These findings suggest a potential role for the extracellular matrix protein mindin in cross-talk between the innate and adaptive immune systems.
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Host defense peptides in skin secretions of Odorrana tiannanensis: Proof for other survival strategy of the frog than merely anti-microbial.
Biochimie
PUBLISHED: 08-06-2011
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Genus Odorrana, among all amphibians studied, is generally reported to have the most abundant and diversified anti-microbial peptides even from a single individual frog. In our previous work, 46 cDNA sequences encoding precursors of 22 different anti-microbial peptides (AMPs) were characterized from the skin of frog, Odorrana tiannanensis. In this work, we reported the purification of three AMPs from skin secretions of O. tiannanensis. Their amino acid sequences matched well with the sequences deduced from cDNAs and they were designated as Odorranain-C7HSa, Brevinin-1-OT2 and Odorranain-G-OT, respectively. Furthermore, we selected to analyze the four most structurally diversified sequences among the 22 AMPs that are significantly different from all reported AMPs. By structural characterization, three of them were designated as pleurain-E-OT, odorranain-G-OT, odorranain-A-OT, belonging to AMP families already identified. The forth one with a unique 14-mer sequence of AILTTLANWARKFLa and C-terminal amidation represents the prototypes of a new class of amphibian AMP, and thereby named tiannanensin. Such broad diversity in sequences and structures are consistent with other species in Genus Odorrana. Multi-functions of the synthesized four special AMPs were screened, including anti-microbial, antioxidant, cytotoxic and hemolytic activities. The results suggest that these AMPs may employ sophisticated mechanisms of action in host defense in addition to anti-microbial, although their precise contribution to host defense still seems unclear.
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The effect of artificial neural network model combined with six tumor markers in auxiliary diagnosis of lung cancer.
J Med Syst
PUBLISHED: 06-21-2011
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To evaluate the diagnosis potential of artificial neural network (ANN) model combined with six tumor markers in auxiliary diagnosis of lung cancer, to differentiate lung cancer from lung benign disease, normal control, and gastrointestinal cancers. Serum carcino-embryonic antigen (CEA), gastrin, neurone specific enolase (NSE), sialic acid (SA), Cu/Zn, Ca were measured through different experimental procedures in 117 lung cancer patients, 93 lung benign disease patients, 111 normal control, 47 gastric cancer patients, 50 patients with colon cancer and 50 esophagus cancer patients, 19 parameters of basic information were surveyed among lung cancer, lung benign disease and normal control, then developed and evaluated ANN models to distinguish lung cancer. Using the ANN model with the six serum tumor markers and 19 parameters to distinguish lung cancer from benign lung disease and healthy people, the sensitivity was 98.3%, the specificity was 99.5% and the accuracy was 96.9%. Another three ANN models with the six serum tumor markers were employed to differentiate lung cancer from three gastrointestinal cancers, the sensitivity, specificity and accuracy of distinguishing lung cancer from gastric cancer by the ANN model of lung cancer-gastric cancer were 100%, 83.3% and 93.5%, respectively; The sensitivity, specificity and accuracy of discriminating lung cancer by lung cancer-colon cancer ANN model were 90.0%, 90.0%, and 90.0%; And which were 86.7%, 84.6%, and 86.0%, respectively, by lung cancer-esophagus cancer ANN model. ANN model built with the six serum tumor markers could distinguish lung cancer, not only from lung benign disease and normal people, but also from three common gastrointestinal cancers. And our evidence indicates the ANN model maybe is an excellent and intelligent system to discriminate lung cancer.
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Preparation, characterization and biodistribution of nanostructured lipid carriers for parenteral delivery of bifendate.
J Microencapsul
PUBLISHED: 05-07-2011
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Nanostructured lipid carrier (NLC)-loaded bifendate (DDB) was prepared by melt-emulsification method to improve drug payloads and liver targeting. The particle size of the prepared formulation analysed by photon correlation spectroscopy (PCS) was 217.4?nm with a narrow polydispersity index (PI) lower than 0.2, meanwhile the loading capacity increased from 4.3% to 15.7% in comparison with DDB-loaded SLN reported in previous study. The zeta potential value was -21.91?mV, and transmission electron microscopy studies revealed NLC of irregularly spherical shape. With respect to lipid polymorphism, a less ordered structure of NLC was confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In addition, tissue distribution of DDB-loaded NLC and DDB solution were carried out in Kunming strain mice. In tested organs, the distribution of DDB-loaded NLC to liver was higher than that of free drug. These results support the potential applications of NLC for the delivery of DDB.
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Virulence regulator PrfA is essential for biofilm formation in Listeria monocytogenes but not in Listeria innocua.
Curr. Microbiol.
PUBLISHED: 04-21-2011
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The ability of the foodborne pathogen Listeria monocytogenes to develop biofilm in food-processing environment is a major concern for the food safety, because biofilms allow bacteria to better resist environmental stresses. PrfA is a key transcriptional activator that positively regulates most of the known listerial virulence gene expression. In order to explore the role of PrfA on Listeria biofilm development, we compared the abilities of biofilm formation by L. monocytogenes wild type strains (EGD and EGDe) and their prfA deletion mutants (EGD?prfA and EGDe?prfA), nonpathogenic Listeria innocua, as well as the recombinant strains that express constitutively active mutant PrfA (PrfA*) in L. innocua (LI-pERL3-prfA*) and in EGDe?prfA (EGDe?prfA-pERL3-prfA*) at 37°C in brain heart infusion (BHI) medium using the polyvinyl chloride (PVC) microtiter plate assay and microscopic examination. Our results showed that the wild types of L. monocytogenes had strong abilities to develop biofilm with meshwork of bacterial aggregates, while biofilm with sparse small clumps were observed in L. innocua. The biofilm production of strains EGD?prfA and EGDe?prfA that lack funtional PrfA was reduced and could be recovered by the introduction of the PrfA*, however, the PrfA* had no impact on the biofilm forming ability of L. innocua. Our results suggest that PrfA plays a significant role in biofilm formation in L. monocytogenes but not in L. innocua, thus may reflect differences in the molecular mechanisms of biofilm formation by these two closely related species.
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Gene cloning, expression and characterization of avian cathelicidin orthologs, Cc-CATHs, from Coturnix coturnix.
FEBS J.
PUBLISHED: 03-25-2011
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Cathelicidins comprise a family of antimicrobial peptides sharing a highly conserved cathelin domain, which play a central role in the early innate host defense against infection. In the present study, we report three novel avian cathelicidin orthologs cloned from a constructed spleen cDNA library of Coturnix coturnix, using a nested-PCR-based cloning strategy. Three coding sequences containing ORFs of 447, 465 and 456 bp encode three mature antimicrobial peptides (named Cc-CATH1, 2 and 3) of 26, 32 and 29 amino acid residues, respectively. Phylogenetic analysis indicated that precursors of Cc-CATHs are significantly conserved with known avian cathelicidins. Synthetic Cc-CATH2 and 3 displayed broad and potent antimicrobial activity against most of the 41 strains of bacteria and fungi tested, especially the clinically isolated drug-resistant strains, with minimum inhibitory concentration values in the range 0.3-2.5 ?m for most strains with or without the presence of 100 mm NaCl. Cc-CATH2 and 3 showed considerable reduction of cytotoxic activity compared to other avian cathelicidins, with average IC(50) values of 20.18 and 17.16 ?m, respectively. They also exerted a negligible hemolytic activity against human erythrocytes, lysing only 3.6% of erythrocytes at a dose up to 100 ?g·mL(-1) . As expected, the recombinant Cc-CATH2 (rCc-CATH2) also showed potent bactericidal activity. All these features of Cc-CATHs encourage further studies aiming to estimate their therapeutic potential as drug leads, as well as coping with current widespread antibiotic resistance, especially the new prevalent and dangerous superbug that is resistant to almost all antibiotics.
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Gene cloning and characterization of novel antinociceptive peptide from the brain of the frog, Odorrana grahami.
Biochimie
PUBLISHED: 02-17-2011
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Amphibian opiate peptides including dermorphins and deltorpins have been recently found only in the skin of South American frogs belonging to the subfamily Phyllomedusinae (Phyllomedusa, Agalychnis and Pachymedusa species). No opiate peptides have ever been identified from other amphibians or organs except skin. Here we report the purification and characterization of a novel antinociceptive peptide named odorranaopin from the homogenates of the frog brains, Odorrana grahami, which is also the first antinociceptive peptide found in Ranidae amphibian. Odorranaopin comprises 17 amino acid residues with the sequence of DYTIRTRLHQESSRKVL (Mr 2102 Da). The cDNA encoding odorranaopin was cloned from the frog brain cDNA library, and it was confirmed to be a specific gene. The odorranaopin precursor deduced is composed of 61 amino acid residues including the predicted signal peptide, acidic spacer peptide and mature odorranaopin positioned at the C-terminus. Odorranaopin could inhibit nociceptive responses induced by formalin and acetic acid. It also inhibited the contractile responses of ileum smooth muscle induced by bradykinin, implying that the antinociceptive activity of odorranaopin possibly results from its blockade on bradykinin or bradykinin receptor functions. Odorranaopin is the first antinociceptive peptide found in Ranidae amphibian.
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A defensin-like antimicrobial peptide from the venoms of spider, Ornithoctonus hainana.
J. Pept. Sci.
PUBLISHED: 02-15-2011
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The defensin-like antimicrobial peptides have been characterized from various other arthropods including insects, scorpions, and ticks. But no natural spider defensin-like antimicrobial peptides have ever been isolated from spiders, except couple of cDNA and DNA sequences of five spider species revealed by previous genomic study. In this work, a defensin-like antimicrobial peptide named Oh-defensin was purified and characterized from the venoms of the spider, Ornithoctonus hainana. Oh-defensin is composed of 52 amino acid (aa) residues including six Cys residues that possibly form three disulfide bridges. Its aa sequence is MLCKLSMFGAVLGV PACAIDCLPMGKTGGSCEGGVCGCRKLTFKILWDKKFG. By BLAST search, Oh-defensin showed significant sequence similarity to other arthropod antimicrobial peptides of the defensin family. Oh-defensin exerted potent antimicrobial activities against tested microorganisms including Gram-positive bacteria, Gram-negative bacteria, and fungi. The cDNA encoding Oh-defensin precursor was also cloned from the cDNA library of O. hainana.
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Chitosan-g-poly(N-isopropylacrylamide) based nanogels for tumor extracellular targeting.
Int J Pharm
PUBLISHED: 01-23-2011
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The principle objective of this research was to develop and characterize pH-responsive and biocompatible nanogels as a tumor-targeting drug delivery system. The nanogels were self-assembled from chitosan-based copolymers, chitosan-graft-poly(N-isopropylacrylamide) (CS-g-PNIPAm). The copolymers were synthesized via free radical copolymerization and characterized for their chemical structure by FT-IR and (1)H NMR. These copolymers could be efficiently loaded with oridonin (ORI) and the characteristics of ORI-loaded nanogels were evaluated. Drug release researches indicated that the ORI-loaded nanogels displayed pH-dependent release behaviors. Based on MTT assay and cellular morphological analysis, the anti-tumor activity of ORI-loaded nanogels was higher at pH 6.5 than at pH 7.4. In conclusion, the obtained nanogels appeared to be of great promise in tumor extracellular pH targeting for ORI.
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SigB plays a major role in Listeria monocytogenes tolerance to bile stress.
Int. J. Food Microbiol.
PUBLISHED: 01-08-2011
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The ability of Listeria monocytogenes to tolerate high levels of bile stress is critical to its successful infection and colonization in the human gastrointestinal tract. L. monocytogenes encodes bile salt hydrolase by a bsh gene which plays a significant role in hydrolyzing high concentrations of bile salt when L. monocytogenes grows under hypoxemic condition. As the bsh promoter contains consensus SigB and PrfA binding sites, we investigated the role of SigB (?(B)) and PrfA in L. monocytogenes tolerance against bile stress by comparing the survival of isogenic deletion mutants of L. monocytogenes EGD(?sigB), EGD(?prfA) and EGD(?prfA?sigB) with their parent strain EGD at high levels of bile salt. Our results show that the sigB deletion significantly reduced the MICs of bile salt for EGD(?sigB) and EGD(?prfA?sigB) (2.6% and 2.2% vs 3.5% in wild type strain EGD), while the growth rates of these two sigB deletion mutants (EGD(?sigB) and EGD(?prfA?sigB)) were affected the most in the presence of 3% bile salt. Pre-exposure to alkali (pH 9.0) and osmotic (0.3M NaCl) stresses for a short period of time (30 min) resulted in improved growth of L. monocytogenes as well as its prfA-sigB isogenic mutants even under sublethal concentrations of bile salt, while pre-exposure to acid pH (pH 4.5) failed to provide cross-protection against subsequent bile stress. Furthermore, the sigB gene had more remarkable influence than that of prfA on bsh expression, as much lower levels of bsh transcription were observed in EGD(?sigB) and EGD(?prfA?sigB). Meanwhile, bsh expression in the deletion mutants did not respond to elevated levels of bile salt. These data indicate that ?(B) might play a crucial role in Listeria survival under bile salt environment in the gastrointestinal tract before its successful colonization, invasion and intracellular propagation.
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Molecular cloning and characterization of novel cathelicidin-derived myeloid antimicrobial peptide from Phasianus colchicus.
Dev. Comp. Immunol.
PUBLISHED: 09-14-2010
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Cathelicidins were initially characterized as a family of antimicrobial peptides. Now it is clear that they fulfill several immune functions in addition to their antimicrobial activity. In the current work, three cDNA sequences encoding pheasant cathelicidins were cloned from a constructed bone marrow cDNA library of Phasianus colchicus, using a nested-PCR-based cloning strategy. The three deduced mature antimicrobial peptides, Pc-CATH1, 2 and 3 are composed of 26, 32, and 29 amino acid residues, respectively. Unlike the mammalian cathelicidins that are highly divergent even within the same genus, Pc-CATHs are remarkably conserved with chicken fowlicidins with only a few of residues mutated according to the phylogenetic analysis result. Synthetic Pc-CATH1 exerted strong antimicrobial activity against most of bacteria and fungi tested, including the clinically isolated (IS) drug-resistant strains. Most MIC values against Gram-positive bacteria were in the range of 0.09-2.95 ?M in the presence of 100mM NaCl. Pc-CATH1 displayed a negligible hemolytic activity against human erythrocytes, lysing 3.6% of erythrocytes at 3.15 ?M (10 ?g/ml), significantly higher than the corresponding MIC. Pc-CATH1 was stable in the human serum for up to 72 h, revealing its extraordinary serum stability. These specific features of Pc-CATH1 may make its applications much wider given the potency and breadth of the peptides bacteriocidal capacity and its resistance towards serum and high-salt environments.
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Development and in vitro evaluation of deacety mycoepoxydiene nanosuspension.
Colloids Surf B Biointerfaces
PUBLISHED: 07-01-2010
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Deacety mycoepoxydiene (DM), extracted from Phomopsis sp. A123 of thalassiomycetes, is a novel and potent anti-cancer agent. Due to its physicochemical characteristics, the drug, a poorly water-soluble weak acid, shows poor solubility and dissolution characteristics. To improve the solubility and dissolution, formulation of DM as nanosuspension has been performed in this study. Nanosuspensions were developed by high-pressure homogenization (HPH) (DissoCubes(®) Technology) and transformed into dry powder by freeze-drying. The nanosuspension produced was then investigated using optical microscope, photon correlation spectroscopy (PCS), zeta potential measurement, SEM, TEM, AFM, DSC and XRD. To verify the theoretical hypothesis on the benefit of increased surface area, in vitro saturation solubility and dissolution profile were investigated. In addition, the in vitro cell cytotoxicity was examined. Results showed that a narrow size distributed nanosuspension composed of unchanged crystalline state with a mean particle size of 515±18 nm, a polydispersity index of 0.12±0.03 and a zeta potential of -23.1±3.5 mV was obtained. In the in vitro dissolution test an accelerated dissolution velocity and increased saturation solubility could be shown for the MD nanosuspension. The in vitro cytotoxicity experiments provided evidence for an enhanced efficacy of the DM nanosuspension formulation compared to free DM solution. Taken together, these results illustrate the opportunity to formulate DM in nanosuspension form as an anti-prostate cancer delivery system.
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Analysis of coal tar pitch and smoke extract components and their cytotoxicity on human bronchial epithelial cells.
J. Hazard. Mater.
PUBLISHED: 05-29-2010
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Coal tar pitch and its smoke are considered hazardous by-products and common pollutant generated from coal industry processing. In this study, coal tar pitch and its smoke extracts were characterized by gas chromatography/mass spectrometry (GC/MS) with dimethylsulfoxide. We identified only 0.3025% of components in the total coal tar pitch using GC/MS. Among 18 identified compounds, polycyclic aromatic hydrocarbons (PAHs) has the highest relative abundance (0.19%). The remaining components were composed of monocyclic aromatic hydrocarbons, heterocyclic compounds and alkenes. In contrast, among 38 coal tar pitch smoke extract constituents that have been profiled, 87.91% were PAHs, and the remaining 12.09% were composed of monocyclic aromatic hydrocarbons, heterocyclic compounds and alkenes. The cytotoxic effect of coal tar pitch and its smoke extracts on BEAS-2B cells were also evaluated by MTT assay. BEAS-2B cells exposed to coal tar pitch showed a non dose-dependent U-shaped cytotoxicity with a dosage for maximal inhibitory of 3.75 mg/L. In contrast, BEAS-2B cells exposed to coal tar pitch smoke extracts showed a dose dependent cytotoxicity with a LC(50) of 8.64 mg/L. Our study demonstrated the significant different composition and cytotoxicity of coal tar pitch and its extracts, suggesting two different underlying mechanisms that are pending future investigation.
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Novel family of antimicrobial peptides from the skin of Rana shuchinae.
Peptides
PUBLISHED: 04-30-2010
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So far numerous antimicrobial peptides have been characterized from amphibians. In this work, a new family of antimicrobial peptides, named shuchin, was purified and characterized from skin secretions of the frog, Rana shuchinae that lives in freezing mountains. Totally two members of shuchin (shuchin 1 and 2) were identified with the amino acid sequence of NALSMPRNKCNRALMCFG and NALSSPRNKCDRASSCFG, respectively. cDNAs encoding shuchins were cloned from the skin cDNA library of R. shuchinae. The precursors of shuchin are composed of 62 amino acid residues including the conserved signal peptides, acidic propieces, and mature antimicrobial peptides. Synthetic shuchins showed strong and broad antimicrobial activities against Gram-positive bacteria (Staphylococcus aureus, and Bacillus cereus; MICs<12.5 microg/ml), Gram-negative bacteria (Escherichia coli, Bacillus dysenteriae, Pseudomonas aeruginosa; most MICs from 3.1 to 12.5 microg/ml), and yeast (Candida albicans; MICs of 6.25 microg/ml), but no hemolytic activity under the effective concentration, thereby provide more leading templates for designing novel anti-infection agents.
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Novel cathelicidin-derived antimicrobial peptides from Equus asinus.
FEBS J.
PUBLISHED: 04-29-2010
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In the present study, EA-CATH1 and EA-CATH2 were identified from a constructed lung cDNA library of donkey (Equus asinus) as members of cathelicidin-derived antimicrobial peptides, using a nested PCR-based cloning strategy. Composed of 25 and 26 residues, respectively, EA-CATH1 and EA-CATH2 are smaller than most other cathelicidins and have no sequence homology to other cathelicidins identified to date. Chemically synthesized EA-CATH1 exerted potent antimicrobial activity against most of the 32 strains of bacteria and fungi tested, especially the clinically isolated drug-resistant strains, and minimal inhibitory concentration values against Gram-positive bacteria were mostly in the range of 0.3-2.4 microg mL(-1). EA-CATH1 showed an extraordinary serum stability and no haemolytic activity against human erythrocytes in a dose up to 20 microg mL(-1). CD spectra showed that EA-CATH1 mainly adopts an alpha-helical conformation in a 50% trifluoroethanol/water solution, but a random coil in aqueous solution. Scanning electron microscope observations of Staphylococcus aureus (ATCC2592) treated with EA-CATH1 demonstrated that EA-CATH could cause rapid disruption of the bacterial membrane, and in turn lead to cell lysis. This might explain the much faster killing kinetics of EA-CATH1 than conventional antibiotics revealed by killing kinetics data. In the presence of CaCl(2), EA-CATH1 exerted haemagglutination activity, which might potentiate an inhibition against the bacterial polyprotein interaction with the host erythrocyte surface, thereby possibly restricting bacterial colonization and spread.
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In vitro and in vivo evaluation of silybin nanosuspensions for oral and intravenous delivery.
Nanotechnology
PUBLISHED: 03-23-2010
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In this study, we evaluate the effect of particle sizes on the physicochemical properties of silybin and identify the influence of silybin nanosuspensions on its permeation across the Caco-2 cell monolayer. In vivo pharmacokinetic evaluation of silybin nanosuspensions was also carried out in beagle dogs. TEM, AFM and SEM analyses revealed the effect of homogenization pressure on particle size and morphology, and confirmed the existence of a surfactant-stabilizer film on the surface of nanoparticles. DSC and XRPD experiments manifested that the crystalline state was maintained as particle size was reduced and the enhanced dissolution property was due to the increased surface area. Nanosuspensions had a significant influence on drug transport across the Caco-2 cell monolayer and the enhanced dissolution velocity was responsible for the increased permeability. A pharmacokinetics study in beagle dogs further confirmed the in vitro results and demonstrated that oral administration of silybin nanosuspensions significantly increase its bioavailability compared to the coarse powder. Nanosuspensions of silybin with smaller particle size reveal a higher potential to increase their oral bioavailability; while for intravenous infusion the lower pressure produced silybin nanosuspensions appeared to maintain a more sustained drug release profile.
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Nanostructured lipid carriers for parenteral delivery of silybin: Biodistribution and pharmacokinetic studies.
Colloids Surf B Biointerfaces
PUBLISHED: 03-17-2010
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The objective of the present study was to explore the potential of nanostructured lipid carriers (NLCs) for the intravenous delivery of silybin, a poorly water-soluble antihepatopathy agent. Silybin-NLC was prepared by the method of emulsion evaporation at a high temperature and solidification at a low temperature. The resultant NLC had a mean size 232.1 nm and a zeta potential of -20.7 mV. The differential scanning calorimetry (DSC) analysis indicated that silybin was not in crystalline state in the NLC. In vitro data for release of the drug from silybin-NLC was fitted to a two-stage exponential kinetic model. The pharmacokinetics and tissue distribution of silybin-NLC were studied after intravenous administration using New Zealand rabbits and Kunming mice as experimental animals. A silybin control solution was studied parallelly. Silybin-NLC showed higher AUC (area under tissue concentration-time curve) values and circulated in the blood stream for a longer time compared with silybin solution. The tissue distribution demonstrated a high uptake of silybin-NLC in RES organs particularly in liver. These results indicate that NLC is a potential sustained release and targeting system for silybin.
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Preparation and characteristics of oridonin-loaded nanostructured lipid carriers as a controlled-release delivery system.
J Microencapsul
PUBLISHED: 02-02-2010
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In order to improve drug entrapment efficiency and loading capacity, nanostructured lipid carriers consisting of solid lipid and liquid lipid as a new type of colloidal drug delivery system were prepared. The dispersions of oridonin-loaded solid lipid nanoparticles and nanostructured lipid carriers were successfully prepared by the emulsion-evaporation and low temperature-solidification technique using monostearin as the solid lipid, caprylic/capric triglycerides as the liquid lipid and oridonin as the model drug. Their physicochemical properties of oridonin-loaded nanostructured lipid carriers and release behaviours were investigated and compared with those of solid lipid nanoparticles. As a result, the mean particle size was approximately 200 nm with narrow polydispersity index lower than 0.4 for all developed formulations. Zeta potential values were in the range -35 mV approximately -50 mV, providing good physical stability of all formulations. The differential scanning calorimetry and X-ray diffraction analysis results demonstrated lipid nanoparticles exhibited crystal order disturbance and thus left more space to accommodate drug molecules. The improved drug entrapment efficiency and loading capacity were observed for nanostructured lipid carriers and they enhanced with increasing the caprylic/capric triglycerides content. In vitro drug release experiments exhibited biphasic drug release patterns with burst release initially and prolonged release afterwards. These results indicated that nanostructured lipid carriers could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release.
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Novel families of antimicrobial peptides with multiple functions from skin of Xizang plateau frog, Nanorana parkeri.
Biochimie
PUBLISHED: 01-29-2010
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Xizang plateau frog (Nanorana parkeri) captured in Lhasa, Tibet, China, solely lives in the subtropical plateau, where there is strong ultraviolet radiation and long duration of sunshine. Considering its harsh living environment, the frogs innate defense against microbes and environmental stress was investigated. In current study, three antimicrobial peptides (AMPs) were purified and characterized from the skin secretion of N. parkeri. The coding cDNA sequences were also cloned from the skin cDNA library of N. parkeri. By structural characterization, two peptides were identified belonging to Japonicin-1 family, and named as Japonicin-1Npa (FLLFPLMCKIQGKC) and Japonicin-1Npb (FVLPLVMCKILRKC). The third peptide isolated named Parkerin with a unique sequence of GWANTLKNVAGGLCKITGAA did not show similarity to any known amphibian AMPs. Multi-functions of three AMPs were examined (antioxidant, MCD, hemolytic etc). Their solution structures determined by CD and antimicrobial mechanisms investigated by SEM are very well consistent with their functional characters. Current result suggests that these novel multi-functional AMPs could play an important role in defending N. parkeri against environmental oxidative stress and pathogenic microorganisms, which may partially reveal the ecological adaptation of these plateau-living amphibians.
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[Comparison and analysis of three classifying models for discrimination of lung cancer established by 6 tumor markers].
Wei Sheng Yan Jiu
PUBLISHED: 08-20-2009
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To distinguish lung cancer by detecting 6 tumor markers in serum and establishing three classifying models of artificial neural networks (ANN), decision tree (CART), Fisher discrimination analysis, and to compare the differences among three models.
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In vitro and in vivo antitumor activity of oridonin nanosuspension.
Int J Pharm
PUBLISHED: 02-06-2009
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The aim of the present study was to evaluate the antitumor activity of an oridonin (ORI) nanosuspension relative to ORI solution both in vitro and in vivo. ORI nanosuspension with a particle size of 897.2+/-14.2 nm was prepared by the high pressure homogenization method (HPH). MTT assay showed that ORI nanosuspension could significantly enhance the in vitro cytotoxicity against K562 cells compared to the ORI solution, the IC(50) value at 36 h was reduced from 12.85 micromol/L for ORI solution to 8.11 micromol/L for ORI nanosuspension. Flow cytometric analysis demonstrated that the ORI nanosuspension also induced a higher apoptotic rate in K562 cells compared to ORI solution. In vivo studies in a mouse model of sarcoma-180 solid tumors demonstrated significantly greater inhibition of tumor growth following treatment with ORI nanosuspension than ORI solution at the same dosage. The mice injected with ORI nanosuspension showed a higher reduction in tumor volume and tumor weight at the dose of 20mg/kg compared to the ORI solution (P<0.01), with the tumor inhibition rate increased from 42.49% for ORI solution to 60.23% for the ORI nanosuspension. Taken together, these results suggest that the delivery of ORI in nanosuspension is a promising approach for the treatment of the tumor.
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Macrophages facilitate coal tar pitch extract-induced tumorigenic transformation of human bronchial epithelial cells mediated by NF-?B.
PLoS ONE
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Chronic respiratory inflammation has been associated with lung cancer. Tumor-associated macrophages (TAMs) play a critical role in the formation of inflammation microenvironment. We sought to characterize the role of TAMs in coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells and the underlying mechanisms.
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Genes of innate immunity and the biological response to inhaled ozone.
J. Biochem. Mol. Toxicol.
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Ambient ozone has a significant impact on human health. We have made considerable progress in understanding the fundamental mechanisms that regulate the biological response to ozone. It is increasingly clear that genes of innate immunity play a central role in both infectious and noninfectious lung disease. The biological response to ambient ozone provides a clinically relevant environmental exposure that allows us to better understand the role of innate immunity in noninfectious airways disease. In this brief review, we focus on (1) specific cell types in the lung modified by ozone, (2) ozone and oxidative stress, (3) the relationship between genes of innate immunity and ozone, (4) the role of extracellular matrix in reactive airways disease, and (5) the effect of ozone on the adaptive immune system. We summarize recent advances in understanding the mechanisms that ozone contributes to environmental airways disease.
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Hyaluronan activation of the Nlrp3 inflammasome contributes to the development of airway hyperresponsiveness.
Environ. Health Perspect.
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The role of the Nlrp3 inflammasome in nonallergic airway hyperresponsiveness (AHR) has not previously been reported. Recent evidence supports both interleukin (IL) 1? and short fragments of hyaluronan (HA) as contributors to the biological response to inhaled ozone.
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Oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.
Int J Nanomedicine
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Oridonin, a diterpenoid isolated from Rabdosia rubescencs, has been reported to have antitumor effects. However, low solubility has limited its clinical applications. Preparation of drugs in the form of nanosuspensions is an extensively utilized protocol. In this study, we investigated the anticancer activity of oridonin and oridonin nanosuspension on human pancreatic carcinoma PANC-1 cells. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to investigate the effect of oridonin on cell growth. Propidium iodide and Hoechst 33342 staining were used to detect morphologic changes. The percentage of apoptosis and cell cycle progression was determined by flow cytometric method staining with propidium iodide. Annexin V-fluorescein isothiocyanate (FITC)/PI staining was used to evaluate cell apoptosis by flow cytometry. Caspase-3 activity was measured by spectrophotometry. The apoptotic and cell cycle protein expression were determined by Western blot analysis. Both oridonin and oridonin nanosuspension induced apoptosis and G(2)/M phase cell cycle arrest, and the latter had a more significant cytotoxic effect. The ratio of Bcl-2/Bax protein expression was decreased and caspase- 3 activity was stimulated. The expression of cyclin B1 and p-cdc2 (T161) was suppressed. Our results showed that oridonin nanosuspension was more effective than free oridonin on G(2)/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.
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Carbon catabolite control is important for Listeria monocytogenes biofilm formation in response to nutrient availability.
Curr. Microbiol.
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The foodborne pathogen Listeria monocytogenes has the ability to develop biofilm in food-processing environment, which becomes a major concern for the food safety. The biofilm formation is strongly influenced by the availability of nutrients and environmental conditions, and particularly enhanced in poor minimal essential medium (MEM) containing glucose rather than in rich brain heart infusion (BHI) broth. To gain better insight into the conserved protein expression profile in these biofilms, the proteomes from biofilm- and planktonic-grown cells from MEM with 50 mM glucose or BHI were compared using two-dimensional polyacrylamide gel electrophoresis followed by MALDI-TOF/TOF analysis. 47 proteins were successfully identified to be either up (19 proteins) or down (28 proteins) regulated in the biofilm states. Most (30 proteins) of them were assigned to the metabolism functional category in cluster of orthologous groups of proteins. Among them, up-regulated proteins were mainly associated with the pentose phosphate pathway and glycolysis, whereas a key enzyme CitC involved in tricarboxylic acid cycle was down-regulated in biofilms compared to the planktonic states. These data implicate the importance of carbon catabolite control for L. monocytogenes biofilm formation in response to nutrient availability.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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