scholarly journals A Lifetime of Adventures in Glycobiology

2018 ◽  
Vol 87 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Stuart Kornfeld
Keyword(s):  
Mammalian Cells ◽  
Lectin Binding ◽  
P System ◽  
Surface Coat ◽  
Research Experience ◽  
Cell Wall Polysaccharides ◽  
Nucleotide Sugars ◽  
Initial Research ◽  
Enzyme Targeting

My initial research experience involved studying how bacteria synthesize nucleotide sugars, the donors for the formation of cell wall polysaccharides. During this time, I became aware that mammalian cells also have a surface coat of sugars and was intrigued as to whether these sugars might be arranged in specific sequences that function as information molecules in biologic processes. Thus began a long journey that has taken me from glycan structural analysis and determination of plant lectin-binding preferences to the biosynthesis of Asn-linked oligosaccharides and the mannose 6-phosphate (Man-6-P) lysosomal enzyme targeting pathway. The Man-6-P system represents an early example of a glycan serving as an information molecule in a fundamental cellular function. The remarkable advances in the field of glycobiology since I entered have uncovered scores of additional examples of oligosaccharide–lectin interactions mediating critical biologic processes. It has been a rewarding experience to participate in the efforts that have established a central role for glycans in biology.

Definitions and concepts of reproductive biology of diatoms (terminological glossary)

2017 ◽  
Vol 51 ◽  
pp. 71-105 ◽  
Author(s):  
N. A. Davidovich
Keyword(s):  
Mating System ◽  
Sexual Reproduction ◽  
Reproductive Biology ◽  
World Literature ◽  
Russian Literature ◽  
Life Cycles ◽  
Transfer Of Knowledge ◽  
Research Experience ◽  
Key Terms

The absence of a conceptual terminology, sufficiently developed and widely accepted in the Russian literature, significantly hinders progress in the field of reproductive biology of diatoms, restricts communication and debate, prevents training and transfer of knowledge. The present work is an attempt, based on world literature and our own research experience, to summarize, systematize, add, and clarify the existing terms, concepts and definitions related to research which are focused on sex and sexual reproduction in diatoms. A glossary of key terms (more than 200, including synonyms) is provided. Terms refer to diatom reproductive biology, life cycles, fertilization, mating system, gender (including inheritance and determination of sex, as well as inheritance associated with sex). Contradictions between possible interpretations of certain terms are briefly discussed.

Rapid determination of transgene copy number in stably-transfected mammalian cells by competitive PCR

1999 ◽  
Vol 40 (3) ◽  
pp. 101-112 ◽  
Author(s):  
Ping Fu ◽  
Paul Senior ◽  
Ross T Fernley ◽  
Geoffrey W Tregear ◽  
G.Peter Aldred
Keyword(s):  
Copy Number ◽  
Mammalian Cells ◽  
Rapid Determination ◽  
Competitive Pcr ◽  
Transgene Copy Number

scholarly journals 3D structure determination of native mammalian cells using cryo-FIB and cryo-electron tomography

2012 ◽  
Vol 180 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Ke Wang ◽  
Korrinn Strunk ◽  
Gongpu Zhao ◽  
Jennifer L. Gray ◽  
Peijun Zhang
Keyword(s):  
Structure Determination ◽  
Mammalian Cells ◽  
Electron Tomography ◽  
3D Structure ◽  
Cryo Electron Tomography ◽  
3D Structure Determination

Role of extracellular signal-regulated kinase (ERK) signaling in nucleotide excision repair and genotoxicity in response to As(III) and Pb(II)

2008 ◽  
Vol 80 (12) ◽  
pp. 2735-2750
Author(s):  
Ju-Pi Li ◽  
Chun-Yu Wang ◽  
Yen-An Tang ◽  
Yun-Wei Lin ◽  
Jia-Ling Yang
Keyword(s):  
Signaling Pathways ◽  
Nucleotide Excision Repair ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Erk Signaling ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Nucleotide Excision

Arsenic and lead can induce genetic injuries and epigenetic signaling pathways in cultured mammalian cells. To test whether signaling pathways affect the extent of genetic injuries, we explored the impacts of extracellular signal-regulated kinase 1 and 2 (ERK) on nucleotide excision repair (NER), cytotoxicity, and genotoxicity following sodium arsenite [As(III)] and lead acetate [Pb(II)]. Sustained ERK activation was observed in human cells exposed to As(III) and Pb(II). As(III) inhibited the cellular NER synthesis capability; conversely, Pb(II) stimulated it. ERK activation contributed to the As(III)-induced NER inhibition and micronucleus formation. In contrast, this signal was required for inducing cellular NER activity and preventing mutagenesis following Pb(II). ERK activation by Pb(II) was dependent on protein kinase C (PKCα) that also exhibited anti-mutagenicity. Enforced expression of ERK signaling markedly elevated the cellular NER activity, which was suppressed by As(III). Nonetheless, ERK activation could counteract the cytotoxicity caused by these two metals. Together, the results indicate that pro-survival ERK signaling exhibits dual and opposing impacts on NER process following As(III) and Pb(II) exposures. The findings also suggest that ERK is an important epigenetic signaling in the determination of metal genotoxicity.

scholarly journals Functional Glyco-Nanogels for Multivalent Interaction with Lectins

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1865 ◽  
Author(s):  
Jo Sing Julia Tang ◽  
Sophia Rosencrantz ◽  
Lucas Tepper ◽  
Sany Chea ◽  
Stefanie Klöpzig ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Lectin Binding ◽  
Host Cells ◽  
Protecting Group ◽  
Reaction Parameters ◽  
Binding Studies ◽  
Huge Number ◽  
Dependent Inhibition ◽  
Tremendous Impact

Interactions between glycans and proteins have tremendous impact in biomolecular interactions. They are important for cell–cell interactions, proliferation and much more. Here, we emphasize the glycan-mediated interactions between pathogens and host cells. Pseudomonas aeruginosa, responsible for a huge number of nosocomial infections, is especially the focus when it comes to glycan-derivatives as pathoblockers. We present a microwave assisted protecting group free synthesis of glycomonomers based on lactose, melibiose and fucose. The monomers were polymerized in a precipitation polymerization in the presence of NiPAm to form crosslinked glyco-nanogels. The influence of reaction parameters like crosslinker type or stabilizer amount was investigated. The gels were characterized in lectin binding studies using model lectins and showed size and composition-dependent inhibition of lectin binding. Due to multivalent presentation of glycans in the gel, the inhibition was clearly stronger than with unmodified saccharides, which was compared after determination of the glycan loading. First studies with Pseudomonas aeruginosa revealed a surprising influence on the secretion of virulence factors. Functional glycogels may be in the future potent alternatives or adjuvants for antibiotic treatment of infections based on glycan interactions between host and pathogen.

Multi-scale modeling of cell survival and death mediated by the p53 network: a systems pharmacology framework

2015 ◽  
Vol 11 (11) ◽  
pp. 3011-3021 ◽  
Author(s):  
Yuan Wang ◽  
Zihu Guo ◽  
Xuetong Chen ◽  
Wenjuan Zhang ◽  
Aiping Lu ◽  
...  
Keyword(s):  
Cell Survival ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Regulatory Process ◽  
Systems Pharmacology ◽  
Multi Scale ◽  
Scale Modeling ◽  
Multi Scale Modeling ◽  
P53 Network

The determination of cell fate is a key regulatory process for the development of complex organisms that are controlled by distinct genes in mammalian cells.

scholarly journals Intermolecular homologous recombination between transfected sequences in mammalian cells is primarily nonconservative.

1987 ◽  
Vol 7 (10) ◽  
pp. 3561-3565 ◽  
Author(s):  
M M Seidman
Keyword(s):  
Resistance Gene ◽  
Mammalian Cells ◽  
Restriction Analysis ◽  
Shuttle Vector ◽  
Recombination Reaction ◽  
Neomycin Resistance Gene ◽  
African Green Monkey Cells ◽  
The Individual ◽  
Neomycin Resistance

Intermolecular recombination in mammalian cells was studied by coinfecting African green monkey cells in culture with two shuttle vector plasmids, each carrying an incomplete but overlapping portion of the gene for neomycin resistance. The region of homology between the two plasmids was about 0.6 kilobases. Recombination between the homology regions could reconstruct the neomycin resistance gene, which was monitored by analysis of progeny plasmids in bacteria. The individual plasmids carried additional markers which, in combination with restriction analysis, allowed the determination of the frequency of formation of the heterodimeric plasmid which would be formed in a conservative recombination reaction between the homologous sequences. Reconstruction of the neomycin resistance gene was readily observed, but only 1 to 2% of the neomycin resistance plasmids had the structure of the conservative heterodimer. Treatment of the plasmids which enhanced the frequency of the neomycin resistance gene reconstruction reaction did not significantly increase the relative frequency of conservative product plasmids. The results support nonconservative models for recombination of these sequences.

scholarly journals CHITOSAN NANOPARTICLES AS DRUG DELIVERY SYSTEM FOR CEPHALEXIN AND ITS ANTIMICROBIAL ACTIVITY AGAINST MULTIIDRUG RESISTENT BACTERIA

2019 ◽  
pp. 14-27 ◽  
Author(s):  
Mona Elassal ◽  
Nagwan El-Manofy
Keyword(s):  
Antimicrobial Activity ◽  
Electron Microscope ◽  
Mammalian Cells ◽  
Synergistic Effects ◽  
Drug Loading ◽  
Chitosan Nanoparticles ◽  
Clinical Isolates ◽  
Antibiofilm Activity ◽  
Diffusion Kinetic

Objective: The evolution of antimicrobial resistance is a universal obstacle that necessities the innovation of more effective and safe antimicrobial alternatives with synergistic properties. The purpose of this study was to investigate the possible improvement of cephalexin antimicrobial treatments by loading into chitosan-based nanoparticles, then evaluate their antibacterial and antibiofilm activities as well as determination of its cytotoxicity. Methods: Chitosan nanoparticles (CSNPs) were prepared by ionic gelation method. Parameters were studied to optimize the particle size of CSNPs including pH, stirring rate, homogenization and ultra-sonication time. Size was measured by transmission electron microscope (TEM) and Zeta sizer, morphology seen by scanning electron microscope (SEM). Entrapment efficiency, drug loading and drug content were calculated. Stability of both plain and loaded chitosan Nano-carriers, Drug release and Kinetics also compatibilities were studied. Antimicrobial activity of CSNPs and cephalexin loaded CSNPs were evaluated against 4 Gram-positive and 4 Gram-negative standard and clinical isolates by microdilution method, also assessment of antibiofilm activity of both formulas was investigated against two biofilm producers clinical isolates by tube assay in addition to determination of their cytotoxicity by MTT(3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results: Chitosan nanoparticles and its loaded antibiotics proved compatible combination with small Zeta size, suitable Zeta potential, maximum EE% and drug-loading capacity, sustained controlled release properties followed diffusion kinetic model and six month stability studies. Cephalexin loaded CSNPs showed better antimicrobial activity than plain CSNPs. Synergistic effects were found against S. aureus (ATCC 25923), B. subtilis (ATCC 9372), S. epidermidis, E. faecalis, P. aeruginosa (ATCC 29853) in addition to two carbapenem resistant isolates k. pneumoniae and E. coli. Also cephalexin loaded CSNPs exhibited antibiofilm activity against E. faecalis clinical isolate. Even though, cephalexin loaded CSNPs exhibited significant antibacterial activity, it showed less toxicity against mammalian cells, it had IC50 equal to 231.893 and did not exhibit any cytotoxicity against the WI-38 fibroblast cells at concentration 23.4 µg/ml. Conclusion: Cephalexin loaded CSNPs possessed good stability and sustained release effect in addition to its antimicrobial, antibiofilm activities and reduced cytotoxicity.

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