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ABSTRACT: In this work, 5-fluorouracil-loaded- poly(l-lactic)-polyethylene glycol/polyethylene glycol (5-FU-loaded-PLLA-PEG/PEG) nanoparticles were prepared using a novel reverse emulsion-solution enhanced dispersion by supercritical fluids (reverse emulsion-SEDS) technique in an effort to obtain an efficient drug delivery system. In the experiment, 5-FU and PEG were dissolved in water PLLA-PEG was dissolved in organic solution, the aqueous solution was added dropwise to the organic solution under magnetic stirring, a reverse emulsion was immediately formed. The reverse emulsion was dried by a SEDS process so that 5-FU-loaded-PLLA-PEG/PEG nanoparticles (5-FU-NPs) were obtained. The particle size, size distribution, surface morphology, and physical and chemical properties of the 5-FU-NPs were investigated by laser diffraction particle size analysis, scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA). The drug encapsulation efficiency (EE), drug loading (DL), in vitro release profile and pharmacokinetics of 5-FU-NPs in rat plasma were investigated by high-performance liquid chromatography (HPLC). The in vivo tumor inhibition effect, increase in lifespan and hepatotoxicity of placebo-NPs, 5-FU and 5-FU-NPs were determined using H22 tumor-bearing ICR mice. These results collectively suggest that 5-FU-NPs prepared using SEDS have potential anti-tumor applications as a controlled drug release dosage form without harmful drug toxicity.
International journal of pharmaceutics 06/2012; 436(1-2):272-81. · 2.96 Impact Factor
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ABSTRACT: Enzybiotics are becoming increasingly recognized as potential alternative therapies for drug-resistant bacteria. Although only a few enzybiotics are currently well characterized, much information is still missing or is unavailable for researchers. The construction of an enzybiotics database would therefore increase efficiency and convenience in investigating these bioactive proteins and thus help reduce or delay the recent increase in antibiotic resistance.
In the present manuscript, we describe the development of a novel and original database called EnzyBase, which contains 1144 enzybiotics from 216 natural sources. To ensure data quality, we limited the source of information to authoritative public databases and published scientific literature. The interface of EnzyBase is easy to use and allows users to rapidly retrieve data according to their desired search criteria and blast the database for homologous sequences. We also describe examples of database-aided enzybiotics discovery and design.
EnzyBase serves as a unique tool for enzybiotic studies. It has several potential applications, e.g. in silico enzybiotic combination as cocktails, and novel enzybiotic design, in response to continuously emerging drug-resistant pathogens. This database is a valuable platform for researchers who are interested in enzybiotic studies. EnzyBase is available online at http://biotechlab.fudan.edu.cn/database/EnzyBase/home.php.
BMC Microbiology 04/2012; 12:54. · 3.04 Impact Factor
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ABSTRACT: Human serine proteinase inhibitor Kazal-type 6 (SPINK6) belongs to the medically important SPINK family. Malfunctions of SPINK members are linked to many diseases, including pancreatitis, skin barrier defects, and cancer. SPINK6 has been shown to selectively inhibit Kallikrein-related peptidases (KLKs) in human skin. As a SPINK protein, it contains a typical Kazal domain, which requires three intramolecular disulfide bonds for correct folding and activity. Preparation of functional protein is a prerequisite for studying this important human factor. Here, we report the successful generation of tagless SPINK6 using a yeast expression system. The recombinant protein was secreted and purified by cation exchange and size-exclusion chromatography. The protein identity was confirmed by MALDI-TOF MS and N-terminal sequencing. Pichia pastoris-derived recombinant human SPINK6 (rhSPINK6) showed higher inhibitory activity against Kallikrein-related peptidase 14 (KLK14) (K(i)=0.16 nM) than previously reported Escherichia coli-derived rhSPINK6 (K(i)=0.5 nM). This protein also exhibited moderate inhibition of bovine trypsin (K(i)=33 nM), while previous E. coli-derived rhSPINK6 did not. The results indicate that P. pastoris is a better system to generate active rhSPINK6, warranting further studies on this medically important SPINK family candidate.
Protein Expression and Purification 12/2011; 82(1):144-9. · 1.59 Impact Factor
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ABSTRACT: Methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as nosocomial pathogens, especially in burn patients, which is the leading cause of their death. A drug delivery system of chitosan-collagen hydrogel incorporated with lysostaphin (CCHL) based on the lysostaphin gauze was developed for MRSA infected burn wounds. CCHL scaffold consisted of numerous interconnected sphericles and tubular bodies with an average diameter of 100-200 µm, 20-60-fold swelling, high water retention capacity, and cell proliferation properties. The minimal inhibitory concentration of CCHL was 0.053 U/mL. By the second week after its application on MRSA infected third-degree burn wounds, no bacteria could be detected and the burn wounds had started healing. Therefore, CCHL should be studied further as a promising candidate of burn treatment dressing against MRSA infections for clinics.
Drug Delivery 04/2011; 18(3):173-80. · 1.46 Impact Factor
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ABSTRACT: Nasal colonization of Staphylococcus aureus (S.aureus) is known as a significant risk factor for nosocomial infections, and clearance of its nasal colonization greatly reduces the risk. In the present study the preparation and characterizations of the chitosan-o/w cream incorporated with lysostaphin (CCL) were described. It showed that the concentration of incorporated lysostaphin had a direct relationship with its release behavior from the cream. It was rapid at 2 and 3.5 mg lysostaphin/g cream and of a more sustained pattern at 5 mg lysostaphin/g cream. Efficacy of lysostaphin released from the CCL cream to inhibit S.aureus growth was higher than that of lysostaphin delivery routinely treated, as demonstrated by the reduction of the mucociliary transport rate (MTR) in contrast to the control graphite particles (p < 0.05). Therefore, it is concluded that drug delivery by the CCL holds its potential as a local nasal anti-S.aureus infection.
Drug Delivery 11/2010; 17(8):617-23. · 1.46 Impact Factor
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ABSTRACT: Lysostaphin, a specific endopeptidase enzyme derived from Staphylococcus aureus, is a bactericidal agent against Staphylococcus and difficult to be drug-resistant. This study established the monoclonal antibody affinity chromatography to obtain lysostaphin of high purity for drug-use standard. The purified Lysostaphin was of > 95% purity and its recovery rate more than 90%. Moreover, the affinity column kept its efficiency of purification invariable after more than 30 times repeat. Also, the dye release assay validated that the purified lysostaphin had significant bactericidal activity. This method was simple and of high efficacy for the lysostaphin purification and showed its potency in commercial production.
Sheng wu gong cheng xue bao = Chinese journal of biotechnology 02/2009; 25(1):147-51.
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ABSTRACT: To elucidate the role of X-ray repair cross-complementing group 1 (XRCC1) R399Q and R194W genotypes in bladder cancer risk, all available studies were considered in the present meta-analysis, with 4152 patients and 5372 controls for R399Q and 3215 patients and 4313 controls for R194W. Studies were identified in PubMed up to June 2008. Overall, the 399Q allele showed no significant effect on bladder cancer compared to 399R allele in all subjects. Insignificant association between R399Q and bladder cancer was observed under other genetic contrasts in worldwide population, Caucasians and never-smokers. Among ever-smokers, protective effects of 399QQ genotype were observed under recessive model [P = 0.004, fixed-effects (FEs) model odds ratio (OR) = 0.65; 95% confidence interval (CI) (0.49, 0.86), I(2) = 0% P(heterogeneity) = 0.57] and homozygote contrast (P = 0.01, FE OR = 0.66; 95% CI (0.49, 0.90), I(2) = 0%, P(heterogeneity) = 0.76). No apparent effect of 194W allele compared to 194R on bladder cancer risk was found in all subjects and Caucasians. It indicated that XRCC1 R399Q and R194W might not be risk factors to bladder cancer, but the 399QQ genotype decreased susceptibility of bladder cancer under recessive model and homozygote contrast among ever-smokers. Further studies based on larger, stratified population were required to explore the role of XRCC1 polymorphisms in bladder cancer risk.
Mutagenesis 10/2008; · 3.18 Impact Factor
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Xin Ye,
Chaoneng Ji, Qingshan Huang,
Chao Cheng,
Rong Tang,
Jian Xu,
Li Zeng,
Jianfeng Dai,
Qihan Wu,
Shaohua Gu,
Yi Xie,
Yumin Mao
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ABSTRACT: Protein kinases (PKs) represent a well studied but most diverse protein superfamily. The covalent, reversible linkage of phosphate to serine, threonine, and tyrosine residues of substrate proteins by protein kinases is probably ubiquitous cellular mechanism for regulation of physiological processes. It is known to us that most signaling pathways impinge at some point on protein kinases. Here we report a human putative receptor protein kinase cDNA STYK1. The STYK1 cDNA is 2749 base pairs in length and contains an open reading frame encoding 422 amino acids. The STYK1 gene is mapped to human chromosome 12p13 and 11 exons were found. RT-PCR showed that STYK1 is widely expressed in human tissues.
Molecular Biology Reports 07/2003; 30(2):91-6. · 2.93 Impact Factor
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Jianfeng Dai,
Yi Xie,
Qihan Wu,
Liu Wang,
Gang Yin,
Xin Ye,
Li Zeng,
Jian Xu,
Chaoneng Ji,
Shaohua Gu, Qingshan Huang,
Robert Chunhua Zhao,
Yumin Mao
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ABSTRACT: Hydroxysteroid dehydrogenases (HSDs) are responsible for the biosynthesis of steroid hormones and play a crucial role in mammalian physiology and development. By large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a novel human hydroxysteroid dehydrogenase-like cDNA (HSDL2). This cDNA is 3211 bp in length, encoding a 418-amino-acid polypeptide, which contains a typical motif for NAD(P)+-binding (TGxxxGxG), an SDR active site motif (S-Y-K) and a sterol carrier protein domain. HSDL2 shows high similarity with the homologues in the mouse and fruit fly. The HSDL2 gene is mapped to chromosome 9q32 and contains 11 exons. RT-PCR analysis shows that the HSDL2 gene is widely expressed in human tissues and the expression levels in liver, kidney, prostate, testis, and ovary are relatively high.
Biochemical Genetics 07/2003; 41(5-6):165-74. · 0.86 Impact Factor
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ABSTRACT: Calcyphosine is a calcium-binding protein containing four EF-hand domains, initially identified as thyroid protein p24. It was first cloned and its counterparts in rabbit, human, and mouse, crayfish and lobster of invertebrate were also cloned. Here we describe the cloning and characterization of a novel human calcyphosine gene. The 3829-bp cDNA encodes a EF-hand Ca(2+)-binding protein homologous to the dog calcyphosine. It also contains two EF-hand Ca(2+)-binding motif. It is abundantly expressed in many tissues including by RT-PCR analysis and believed to play important role in calcium signaling. It was mapped to human genome 12q15.
Biochemical and Biophysical Research Communications 03/2002; 291(2):414-20. · 2.48 Impact Factor
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ABSTRACT: We have cloned a novel human gene ( C14orf5) from a fetal brain cDNA library that is located on chromosome 14 and consists of 4 exons. It encodes a protein of 170 amino acids that shares homology with human p25 alpha and bovine p25. Reverse transcription-polymerase chain reaction analysis indicated that it is highly expressed in liver and pancreas. Its transcripts could not be detected in adult brain but could be found in fetal brain.
Journal of Human Genetics 02/2002; 47(5):266-8. · 2.57 Impact Factor
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ABSTRACT: Calcyphosine is a calcium-binding protein containing four EF-hand domains, initially identified as thyroid protein p24. It was first cloned and its counterparts in rabbit, human, and mouse, crayfish and lobster of invertebrate were also cloned. Here we describe the cloning and characterization of a novel human calcyphosine gene. The 3829-bp cDNA encodes a EF-hand Ca2+-binding protein homologous to the dog calcyphosine. It also contains two EF-hand Ca2+-binding motif. It is abundantly expressed in many tissues including by RT-PCR analysis and believed to play important role in calcium signaling. It was mapped to human genome 12q15.
Biochemical and Biophysical Research Communications.
