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PHA; antibiotic

Mădălina Elena Grigore, Ramona Marina Grigorescu, Lorena Iancu, Rodica-Mariana Ion, Cătălin Zaharia, Elena Ramona Andrei
This study aims to provide an overview of the main polyhydroxyalkanoates (PHAs) used in medical applications. In this review, it has been demonstrated that the properties of PHAs can be controlled both by varying the concentration of units in the copolymer and the substrate for PHA production. Another way of controlling the mechanical properties of PHAs is varying the 3HV content, such as the case of P(3HB-co-3HV). A higher 3HV content in the structure of this polyester will lead to a lower cristallinity and, therefore, to greater flexibility, strength and elongation at break...
April 23, 2019: Journal of Biomaterials Science. Polymer Edition
Marina Hauser, Guangyu Li, Bernd Nowack
BACKGROUND: The increasing development and use of nanobiomaterials raises questions about their potential adverse effects on the environment after excretion and release. Published ecotoxicological data was searched for five polymeric nanobiomaterials [chitosan, polylactic acid (PLA), polyacrylonitrile (PAN), polyhydroxyalkanoates (PHA), and poly(lactic-glycolic acid) (PLGA)] and one inorganic nanobiomaterial [hydroxyapatite (HAP)] to evaluate the environmental hazards for freshwater and soil using a meta-analysis...
April 16, 2019: Journal of Nanobiotechnology
Edmar Ramos Oliveira-Filho, Linda P Guamán, Thatiane Teixeira Mendonça, Paul F Long, Marilda Keico Taciro, José Gregório Cabrera Gomez, Luiziana F Silva
Three different polyhydroxyalkanoate (PHA) synthase genes (Ralstonia eutropha H16, Aeromonas sp. TSM81 or Aeromonas hydrophila ATCC7966 phaC) were introduced into the chromosome of two Pseudomonas strains: a native medium-chain-length 3-polyhydroxyalkanoate (PHAMCL) producer (Pseudomonas sp. LFM046) and a UV-induced mutant strain unable to produce PHA (Pseudomonas sp. LFM461). We reported for the first time the insertion of a chromosomal copy of phaC using the transposon system mini-Tn7. Stable antibiotic marker-free and plasmid-free recombinants were obtained...
February 19, 2019: Journal of Molecular Microbiology and Biotechnology
Yuzhang Liu, Qiang Du, Chengbang Ma, Xinping Xi, Lei Wang, Mei Zhou, James F Burrows, Tianbao Chen, Hui Wang
Background: Antimicrobial peptides (AMPs) from the skin secretions of amphibians are now considered as a potential alternative to conventional antibiotics. Phylloseptins are a family of AMPs identified in the skin secretions of Phyllomedusinae tree frogs which exhibit highly conserved structural characteristics. This study examines the structure-activity relationship of the newly discovered phylloseptin, Phylloseptin-PHa (PSPHa) from Pithecopus hypochondrialis . Materials and methods: PSPHa and modified analogs were produced by solid phase synthesis and purified by reverse-phase HPLC...
2019: Drug Design, Development and Therapy
H Valpotić, I Zura Zaja, M Samardzija, B Habrun, M Ostović, D Duricić, N Maćesić, Z Mikulec, P Kocila, P Sobiech, I Valpotić, S Vince
The aim of this study was to assess modulatory effects of dietary supplements mannan oligosaccharide (MOS) and clinoptilolite (CPL) as potential alternatives to antibiotic growth promoters (AGP) given to 4-week old pigs at weaning (Day 0) on their innate/adaptive immunity by determining: alterations in C-reactive protein (CRP) and haptoglobin (HpG) serum levels, efficiency of blood monocytes (MO) and neutrophilic granulocytes (GR) for in vitro phagocytosis (PHC)/microbicidity (MBC) and proportion of extrathymic double positive CD4 CD8 (CD4+CD8+) T cells throughout 35 days of the study...
March 2018: Polish Journal of Veterinary Sciences
C Beinke, M Port, R Ullmann, K Gilbertz, M Majewski, M Abend
Dicentric chromosome analysis (DCA) is the gold standard for individual radiation dose assessment. However, DCA is limited by the time-consuming phytohemagglutinin (PHA)-mediated lymphocyte activation. In this study using human peripheral blood lymphocytes, we investigated PHA-associated whole genome gene expression changes to elucidate this process and sought to identify suitable gene targets as a means of meeting our long-term objective of accelerating cell cycle kinetics to reduce DCA culture time. Human peripheral whole blood from three healthy donors was separately cultured in RPMI/FCS/antibiotics with BrdU and PHA-M...
June 2018: Radiation Research
Martin Koller
Polyhydroxyalkanoates (PHA) are bio-based microbial biopolyesters; their stiffness, elasticity, crystallinity and degradability are tunable by the monomeric composition, selection of microbial production strain, substrates, process parameters during production, and post-synthetic processing; they display biological alternatives for diverse technomers of petrochemical origin. This, together with the fact that their monomeric and oligomeric in vivo degradation products do not exert any toxic or elsewhere negative effect to living cells or tissue of humans or animals, makes them highly stimulating for various applications in the medical field...
February 8, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Ru-Gang Zhang, Xiu-Li Zhang, Yun-Sheng Yang
Pyogenic hepatic abscess (PHA) is a rare, but potentially serious disease. At present, ultrasound-guided or computed tomography-guided percutaneous needle aspiration or catheter drainage is appropriate as a first-line treatment. However, it is difficult to aspirate or drain pus and to select the appropriate antibiotic therapy if the abscess consists of thick pus and polymicrobial confections, or its pathogenic bacterium is multidrug resistant and cryptogenic. Case studies of alcoholization provide a novel method to manage PHA...
November 2017: Experimental and Therapeutic Medicine
Parveen K Sharma, Riffat I Munir, Teresa de Kievit, David B Levin
Pseudomonas chlororaphis PA23 was isolated from soybean roots as a plant-growth-promoting rhizobacterium. This strain secretes a wide range of compounds, including the antibiotics phenazine-1-carboxylic acid (PCA), pyrrolnitrin, and 2-hydroxyphenazine. We have determined that P. chlororaphis PA23 can synthesize medium-chain-length polyhydroxyalkanoate (PHA) polymers utilizing free fatty acids, such as octanoic acid and nonanoic acid, as well as vegetable oils as sole carbon sources. Genome analysis identified a pha operon containing 7 genes in P...
December 2017: Canadian Journal of Microbiology
Jia Liu, Qing Wu, Lei Li, Xinping Xi, Di Wu, Mei Zhou, Tianbao Chen, Chris Shaw, Lei Wang
The growing occurrence of bacterial resistance to conventional antibiotics has called for the development of new classes of antimicrobial agents. Antimicrobial peptides (AMPs) with broad antimicrobial spectrum derived from frog skin secretions have been demonstrated to be promising candidates for new antibiotic development. A proven rich source of these compounds are the skin secretions of the frogs in the Phyllomedusa genus. In this study, two novel phylloseptin peptides-phylloseptin-PTa and phylloseptin-PHa-were isolated from the skin secretions of the South American frogs, Phyllomedusa tarsius ( P...
August 29, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Kyle Rowe, Fredy Nehme, Jacob Wallace, Travis McKenzie, Akash Joshi, William Salyers
Primary hepatic angiosarcoma (PHA), a rare and aggressive malignancy, has rarely been reported to present with disseminated intravascular coagulation with liver hemorrhage. Incidence is estimated at 0.5-2.5 cases per 10,000,000. To our knowledge, it has not been reported to mimic liver abscess with a septic presentation. Advanced imaging techniques may aid in the diagnosis, though biopsy with microscopy and immunohistochemistry is the mainstay. Prognosis is very poor, with a 5-year survival rate estimated at 6...
May 30, 2017: Curēus
Hai Wang, Xiao-Qing He, Tao Jin, Yang Li, Xin-Yu Fan, Yi Wang, Yong-Qing Xu
BACKGROUND: Infected bone defect poses a great challenge for orthopedists because it is difficult to cure. Tissue-engineered bone based on the human mesenchymal stem cells (hMSCs), has currently taken a promising treatment protocol in clinical practice. In a previous study, a porous hydroxyapatite/fibronectin/alginate (PHA/FN/ALG) composite scaffold displayed favorable biological properties as a novel scaffold, which was considered better than single-material scaffolds. In addition, Wnt11 has been demonstrated to play an important role in the development of osteoblasts, but until recently, its role in the osteogenic differentiation of hMSCs in infectious environment remained unclear...
January 27, 2016: Stem Cell Research & Therapy
Houda Belguendouz, Karima Lahmar-Belguendouz, Djamel Messaoudene, Zineb Djeraba, Fifi Otmani, Djennat Hakem, Ouided S Lahlou-Boukoffa, Pierre Youinou, Chafia Touil-Boukoffa
Aim and Methods. In this study, we evaluated NOS and arginase activities and their regulation during Behçet disease, a systemic chronic inflammatory disorder with uncertain etiology. The peripheral blood mononuclear cells of 36 patients and 15 control samples (PBMC) were cultured in either RPMI 1640, MEM, or DMEM complemented with 10% of FBS and antibiotics. Cultures were performed with or without the control or patients plasma. Subsequent treatment contained anticytokines (IL-6, TGF-β), a mitogenic effector (PHA), or NOS modulators (L-NMMA, BH4)...
2015: International Journal of Inflammation
José I Obeso, José L Gómez-Botrán, Elías R Olivera, José M Luengo
Pseudomonas putida N, a poly-3-hydroxyalkonate (PHA)-producing bacterium, showing ampicillin resistance, is an unusual strain. In the presence of this antibiotic, it grows as giant cells (25-50μm) forming complex networks inter-connected by micro-tubular structures. The transformation of this bacterium with a plasmid containing the gene phaF, which encodes a phasin involved in the molecular architecture of the PHA-granules, (i) restores the wild-type phenotype by reducing both bacterial size and length (coco-bacilli ranging between 0...
April 10, 2015: Journal of Biotechnology
Oliver Raschdorf, Jürgen M Plitzko, Dirk Schüler, Frank D Müller
Magnetotactic bacteria have emerged as excellent model systems to study bacterial cell biology, biomineralization, vesicle formation, and protein targeting because of their ability to synthesize single-domain magnetite crystals within unique organelles (magnetosomes). However, only few species are amenable to genetic manipulation, and the limited methods for site-specific mutagenesis are tedious and time-consuming. Here, we report the adaptation and application of a fast and convenient technique for markerless chromosomal manipulation of Magnetospirillum gryphiswaldense using a single antibiotic resistance cassette and galK-based counterselection for marker recycling...
July 2014: Applied and Environmental Microbiology
Dieter Seebach
The roles of polyhydroxy-butyrates/alkanoates (PHB/PHA) in biology, for the preparation of chiral building blocks, and as a source of inspiration for the discovery of β- and γ-peptides are discussed. The syntheses and structures of β-peptides are outlined. The prerequisites for mimicking peptide/protein interactions with β-peptides and two examples are presented. Single terminal β-amino-acid residues can lead to stabilization of peptides (cf. NTS(8-13)) in plasma. Cell-penetrating α-L-, α-D-, mixed α-L/D- and β-oligoarginines (OAs) and -oligoprolines, as well as the mechanism(s) of internalization are compared...
2013: Chimia
Shan-Yu Chen, Yi-Wen Chien, Yun-Peng Chao
D-P-Hydroxyphenylglycine (D-HPG) is a precursor required for the synthesis of semi-synthetic antibiotics. This unnatural amino acid can be produced by a transformation reaction mediated by D-hydantoinase (D-HDT) and d-amidohydrolase. In this study, a method was developed to integrate production and immobilization of recombinant D-HDT in vivo. This was approached by first fusion of the gene encoding D-HDT with phaP (encoding phasin) of Ralstonia eutropha H16. The fusion gene was then expressed in the Escherichia coli strain that carried a heterologous synthetic pathway for polyhydroxyalkanoate (PHA)...
July 2014: Journal of Bioscience and Bioengineering
Jose Roberto Gonzales, Sabine Groeger, Anders Johansson, Jörg Meyle
OBJECTIVE: In this study, we analyzed the production of Interleukin-1 beta (IL-1β) and IL-6 by activated CD4+ cells obtained from aggressive periodontitis (AgP) patients in comparison with healthy subjects (HC). MATERIALS AND METHODS: CD4+ cells were automatically separated from lymphocytes obtained from peripheral blood of patients with AgP and healthy controls. Cells were activated for 4, 8, and 24 h with three different stimuli: anti-CD3/anti-CD28, phytohemagglutinin (PHA), and Porphyromonas gingivalis (P...
September 2014: Clinical Oral Investigations
Yan-qiong Wang, Yu-xia Cui, Jie Feng
OBJECTIVE: Omenn syndrome is a rare autosomal recessive hereditary severe combined immunodeficiency. The purpose of this study was to understand clinical characteristics and genetic mutation type of Omenn syndrome and to improve the recognition of Omenn syndrome among pediatric clinicians. METHOD: One suspected case of severe combined immunodeficiency was found to have pneumonia repeatedly, intractable diarrhea, poor antibiotic treatment effect, lymphadenopathy, hepatosplenomegaly and erythroderma...
January 2013: Zhonghua Er Ke za Zhi. Chinese Journal of Pediatrics
Wenbin Guo, Jun Feng, Weitao Geng, Cunjiang Song, Yuanyuan Wang, Ning Chen, Shufang Wang
Pseudomonas mendocina NK-01 can simultaneously synthesize medium-chain-length polyhydroxyalkanoate (PHA(MCL)) and alginate oligosaccharides (AO) from glucose under conditions of limited nitrogen. In this study, the PHA(MCL) synthesis pathway was blocked by a deletion of approximately 57% of the sequence of PHA synthase operon mediated by the suicide plasmid, pEX18TcC1ZC2Amp. Deletion of the PHA synthase operon in P. mendocina NK-01 was confirmed by polymerase chain reaction (PCR) and antibiotic resistance assays to form the gene knockout mutant, P...
May 1, 2012: Carbohydrate Research
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