• Title/Summary/Keyword: $In$ $vitro$ degradation

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Pleiotropic Roles of Metalloproteinases in Hematological Malignancies: an Update

  • Chaudhary, Ajay K;Chaudhary, Shruti;Ghosh, Kanjaksha;Nadkarni, A
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3043-3051
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    • 2016
  • Controlled remodeling of the extracellular matrix (ECM) is essential for cell growth, invasion and metastasis. Matrix metalloproteinases (MMPs) are a family of secreted, zinc-dependent endopeptidases capable of degradation of ECM components. The expression and activity of MMPs in a variety of human cancers have been intensively studied. They play important roles at different steps of malignant tumor formation and have central significance in embryogenesis, tissue remodeling, inflammation, angiogenesis and metastasis. However, increasing evidence demonstrates that MMPs are involved earlier in tumorigenesis. Recent studies also suggest that MMPs play complex roles in tumor progression. MMPs and membrane type (MT)-MMPs are potentially significant therapeutic targets in many cancers, so that designing of specific MMP inhibitors would be helpful for clinical trials. Here, we review the pleiotropic roles of the MMP system in hematological malignancies in-vitro and in-vivo models.

Characterization of Benzoate Degradation via ortho-Cleavage by Streptomyces setonii

  • An, Hae-Reun;Park, Hyun-Joo;Kim, Eung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.10 no.1
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    • pp.111-114
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    • 2000
  • Streptomyces are widespread in nature and play a very important role in the biosynthesis as well as biodegradation of natural and unnatural aromatic compounds. Both qualitatively and quantitatively through TLC and UV spectrophotometric assays, it was observed that the thermophilic soil bacteria S. setonii (ATCC 39116), which can utilize a benzoate as a sole carbon and energy source in a minimal liquid culture, was not very sensitive to the benzoate concentation and to the culture conditions such as the pH and temperature. The in vitro conversion of a catechol to a cis, cis-muconic acid by a crude S. setonii lysate implies that the aromatic ring cleavage by S. setonii is initiated by a thermostable catechol-1,2-dioxygenase, the key enzyme in the ortho-cleavage pathway of aromatic compound biodegradation. Unlike non-degrading S. lividans, S.setonii was also highly resistant to other similar hazardous aromatic compounds, exhibiting almost no adverse effect on its growth in a complex liquid culture.

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Role of Unstable Phenanthrene-Degrading Pseudomonas species in Natural Attenuation of Phenanthrene-Contaminated Site

  • Prakash, Om;Lal, Rup
    • Microbiology and Biotechnology Letters
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    • v.41 no.1
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    • pp.79-87
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    • 2013
  • An unstable yet efficient phenanthrene-degrading bacterium strain Ph-3 was isolated from a petroleum-contaminated site at the Mathura Oil Refinery, India. The strain was identified as Pseudomonas sp. using a polyphasic approach. An analysis of the intermediates and assays of the degradative enzymes from a crude extract of phenanthrene-grown cells showed a novel and previously unreported pattern of 1, 2-dihydroxy naphthalene and salicylic acid production. While strain Ph-3 lost its phenanthrene- degrading potential during successive transfers on a rich medium, it maintained this trait in oligotrophic soil conditions under the stress of the pollutant and degraded phenanthrene efficiently in soil microcosms. Although the maintenance and in vitro study of unstable phenotypes are difficult and such strains are often missed during isolation, purification, and screening, these bacteria constitute a substantial fraction of the microbial community at contaminated sites and play an important role in pollutant degradation during biostimulation or monitored natural attenuation.

Intravascular Tumour Targeting of Aclarubicin-loaded Gelatin Microspheres Preparation biocompatibility and biodegradability

  • Lee, Kang-Choon;Koh, Ik-Bae
    • Archives of Pharmacal Research
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    • v.10 no.1
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    • pp.42-49
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    • 1987
  • This study is to evaluate the potential use of aclarubicin-loaded gelatin microspheres as an intravascular biodegradable drug delivery system for the regional cancer therapy. The diameter of the microspheres prepared by water in oil emulsion polymerization could be controlled by adjusting the stirring rate in the range of 10-50 $\mu$m : D(in $\mu$m) = -73.8 log (rpm) + 262.7. The addition of proteolytic enzyme increased the in vitro aclarubicin release but it did not change the amount of the initial burst release which reached about 45%. Microspheres injected intravenously into the mouse tail vein embolized only to the lung when observed by fluorescence microscopy. From histological examination following injection of gelatin microspheres into mouse femoral muscle, mild inflammation was observed from the appearance of neutrophils after 2 days and rapid repair process was confirmed thereafter. Biodegradation process of gelatin microspheres lodged on the pulmonary capillary bed was followed up by microscopic observation; degradation was taking place by about 36 hrs, followed by severe damage on the spheerical shape and microspheres was no longer found 10 days after injection.

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INHIBITORY EFFECT OF THE IONOPHORE SALINOMYCIN ON DEAMINATION BY MIXED RUMEN BACTERIA

  • Kobayashi, Y.;Suda, K.;Wakita, M.;Baran, M.;Hoshino, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.1
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    • pp.45-49
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    • 1996
  • A series of in vitro experiments was conducted to investigate response of rumen bacterial deamination to the ionophore salinomycin. Addition of salinomycin to the inoculum, strained rumen fluid, depressed ammonia production from casein, while increased accumulation of ${\alpha}$-amino acids. This suggests an inhibitory effect of salinomycin on ruminal deamination. When the effect in washed bacterial suspension was monitored with individual amino acid, aspartic acid degradation was markedly inhibited by salinomycin. This inhibition was not observed when the mixed rumen bacteria were ultrasonically disrupted and used as the enzyme source. Extent of the inhibition tended to be higher in the bacteria source from sheep on a high roughage diet. From these results it was speculated that the inhibition of deamination with salinomycin is caused by a decreased transport of amino acid into the bacterial cells as well as a decreased proportion of deaminating bacteria in the rumen.

Development of Research into Autophagic Lysosome Reformation

  • Chen, Yang;Yu, Li
    • Molecules and Cells
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    • v.41 no.1
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    • pp.45-49
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    • 2018
  • Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

Biodistribution and Hemolysis Study of Terplex Gene Delivery System in Mice

  • Oh, Eun-Jung;Shim, Jin-young;Kim, Jin-Seok
    • Macromolecular Research
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    • v.11 no.1
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    • pp.19-24
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    • 2003
  • Polymeric gene delivery system attracts profound attention as it shows less toxicity, versatility, and reasonable gene expression efficiency. Terplex system, a synthetic biopolymeric gene delivery system consisting of stearyl poly-L-lysine (stearyl-PLL) and low density lipoprotein (LDL) was evaluated for its body distribution of gene expression of exogenously administered pDNA after tail-vein injection in mice. Kidney and spleen are two major organs with highest gene expression, whereas liver and heart showed marginal gene expression among the organs examined. Hemolytic effect of the terplex system was evaluated using human red blood cells, where terplex system did not cause significant hemolysis at the concentrations above the experimental ranges, although unmodified PLL or stearyl-PLL without LDL did. Serum stability of terplex system against enzymatic degradation was also significantly enhanced, presumably due to the steric stabilization from the polymers. Based on these findings and along with its high in vitro transfection efficiency, terplex system could serve as a safe and efficient polymeric gene delivery system with many applications for the in vivo gene therapy.

Hydrophilic Albumin Microspheres as Cytarabine Carriers

  • Kim, Chong-Kook;Chung, Myung-Hoa;Oh, Yu-Kyoung;Lah, Woon-Lyong
    • Archives of Pharmacal Research
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    • v.16 no.2
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    • pp.123-128
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    • 1993
  • The surface of cyarabine-entrapped albumin microspheres, the surface modified albumin microspheres hsowed remakably incrased hydrophilicity, good dispersability in aqueous medium and reduced aggregation during storage which met the requirements of injectable drug carriers in acqueous vehicle. In vitro cytarabine release from hydrophilic albumin microspheres (HAM) was a function of the cytarabine to albumin ratio, whereas no significant difference in the releasing capacity was obnserved between surface modified HAM within the small size range$(2\;to\;5\mu{m)}$ studied. HAM containing 15-23% drug were gradually degraded by protease and continuously released up to 60% of the total entrapped cytarabine for 6h. These results thus suggest that HAM is a suitable cytarabine carrier which may be injected intraveneously with the benefits of a reduced risk of blood embolism induced by aggregates and prolonged cytarabine release.

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New Method of Injectable Hydrogels by Novel Photo-polymerization

  • Lee, Seung-Young;Tae, Gi-Yoong
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.252-252
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    • 2006
  • Utilizing the existence of the induction period in photo-polymerization, we propose a new injection method of photo-polymerizable, thermocrosslinking hydrogels made of di-acrylated Pluronic F127 (DA-PF127). This method can solve the problem of fast dissolution of thermal gelation as a scaffold and the disadvantages of the existing injection method that photo-polymerize di-acrylated Pluronic polymer after injection using optical fiber. Injectable gelation of DA-PF127 by the proposed method was demonstrated both in vitro and in vivo. The enhanced stability by this novel photo-polymerization strategy was confirmed by the more sustained release of loaded protein as well as the prolonged degradation time of the hydrogels.

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Effects of Bacterial Fraction and Proportion of Silage and Concentrate on Rumen Fermentation and Gas Production Profile

  • Lee, Sang S.;Chang, M.B.;Ha, J.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.5
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    • pp.643-647
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    • 2004
  • An in vitro experiment was carried out to investigate effects of solid associated (SAB) and liquid associated bacteria (LAB) and the type of incubation substrate on ruminal fermentation and gas production profiles. Bacterial fraction did not influence total numbers of bacteria. Gas production degradation parameters were significantly influenced by bacterial fraction and type of substrate (p<0.05). There was significant interaction between bacterial fraction and type of substrate in gas production (p<0.01). Total VFA concentration and acetic and propionic acid ratio were also influenced by bacterial fraction and type of substrate with little differences in individual VFA concentration.