scholarly journals A bioorthogonal time-resolved luminogenic probe for metabolic labelling and imaging of glycans

2020 ◽  
Vol 7 (21) ◽  
pp. 4062-4069 ◽  
Author(s):  
Judun Zheng ◽  
Qiuqiang Zhan ◽  
Lijun Jiang ◽  
Da Xing ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Cell Surface ◽  
Fold Increase ◽  
Terbium Complex ◽  
Time Resolved ◽  
Metabolic Labelling ◽  
Low Toxicity ◽  
Cell Surface Glycans

A terbium complex Tb-1 was demonstrated to undergo bioorthogonal ligation with engineered cell-surface glycans, which results in a much less efficient LRET and a 5-fold increase in long-lived terbium emission with low toxicity.

Potential of Nanoparticles in Combating Candida Infections

2019 ◽  
Vol 16 (5) ◽  
pp. 478-491 ◽  
Author(s):  
Faizan Abul Qais ◽  
Mohd Sajjad Ahmad Khan ◽  
Iqbal Ahmad ◽  
Abdullah Safar Althubiani
Keyword(s):  
Targeted Delivery ◽  
Recent Progress ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Fold Increase ◽  
Antifungal Drugs ◽  
Low Toxicity ◽  
Candida Infections ◽  
Made In

Aims: The aim of this review is to survey the recent progress made in developing the nanoparticles as antifungal agents especially the nano-based formulations being exploited for the management of Candida infections. Discussion: In the last few decades, there has been many-fold increase in fungal infections including candidiasis due to the increased number of immunocompromised patients worldwide. The efficacy of available antifungal drugs is limited due to its associated toxicity and drug resistance in clinical strains. The recent advancements in nanobiotechnology have opened a new hope for the development of novel formulations with enhanced therapeutic efficacy, improved drug delivery and low toxicity. Conclusion: Metal nanoparticles have shown to possess promising in vitro antifungal activities and could be effectively used for enhanced and targeted delivery of conventionally used drugs. The synergistic interaction between nanoparticles and various antifungal agents have also been reported with enhanced antifungal activity.

scholarly journals 1186. Cefazolin inoculum effect predicts reduced susceptibility to other antibiotics and patient outcomes in MSSA endovascular infections

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S617-S617
Author(s):  
Dan Smelter ◽  
Sue McCrone ◽  
Warren Rose
Keyword(s):  
Infective Endocarditis ◽  
Mortality Rate ◽  
Patient Outcomes ◽  
Treatment Options ◽  
Fold Increase ◽  
Specific Mechanism ◽  
Research Support ◽  
High Burden ◽  
Low Toxicity ◽  
Inoculum Effect

Abstract Background MSSA Infective endocarditis (IE) is inherently a high-burden infection with up to a 30% mortality rate. Cefazolin is an appealing treatment option for IE with low toxicity and a favorable dosing scheme. However, cefazolin has been associated with treatment failure in IE, attributed to an inoculum effect. The specific mechanism underlying the cefazolin inoculum effect (CIE) remains undetermined, but CIE has been linked to both blaZ expression and agr dysfunction. This study aims to determine whether CIE is linked to reduced susceptibility to other antibiotics and worse outcomes regardless of therapy in MSSA endovascular infections. Methods Sixty-four MSSA strains were collected from patients with endovascular infections not treated with cefazolin. To determine CIE phenotype, strains were cultured and MICs assayed for cefazolin, nafcillin, and vancomycin at 107 CFU/mL for high-inocula (HI) and 105 CFU/mL for standard-inocula (SI). This study defined CIE as a ≥ 4-fold increase in MIC at HI compared to SI, with at least an MIC of 4 mg/L at HI. Nitrocefin disks identified blaZ expression, and beta lysin disks were used to determine hemolysin type and agr function. Patient outcomes of mortality and bacteremia duration were assessed across cohorts. Results Twenty-four strains exhibit a CIE (38%), with 10 strains having an MIC of ≥ 32mg/L at HI. Nafcillin and vancomycin also had an inoculum effect, uncoupled from the CIE and occurring at a lower frequency and amplitude at HI. Presence of CIE had a greater association with blaZ expression (71% vs 25%) than agr dysfunction (38% vs 20%). 50% (9/18) of CIE infections were cleared within 48 hours while 77% (20/26) of CIE-negative infections were cleared within 48 hours (P=0.106). However, presence of CIE was not associated with increased mortality (25% CIE-positive vs 35%; P=0.578) Conclusion Previous studies for CIE failed to enrich for isolates from endovascular sources, where inocula are known to be high. This study presents one of the largest endovascular source cohorts for CIE evaluation. It identifies that CIE prevalence (38%) is higher than reports from diverse infection sources (10-36%). CIE appears to predict bacteremia duration with other MSSA treatment options, suggesting mechanisms independent of blaZ and agr function for this phenomenon. Disclosures Warren Rose, PharmD, MPH, Merck (Grant/Research Support)Paratek (Grant/Research Support)

scholarly journals Identification of cell-surface glycans that mediate motility-dependent binding and internalization of Pseudomonas aeruginosa by phagocytes

2020 ◽  
Author(s):  
Hector Sanchez ◽  
Daniel Hopkins ◽  
Sally Demirdjian ◽  
Cecilia Gutierrez ◽  
George A. O’Toole ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Surface ◽  
Cell Surface Glycans

scholarly journals Cell-surface protein-protein interaction analysis with time-resolved FRET and snap-tag technologies: application to GPCR oligomerization

2008 ◽  
Vol 5 (6) ◽  
pp. 561-567 ◽  
Author(s):  
Damien Maurel ◽  
Laëtitia Comps-Agrar ◽  
Carsten Brock ◽  
Marie-Laure Rives ◽  
Emmanuel Bourrier ◽  
...  
Keyword(s):  
Cell Surface ◽  
Protein Interaction ◽  
Interaction Analysis ◽  
Surface Protein ◽  
Cell Surface Protein ◽  
Time Resolved ◽  
Protein Protein Interaction

Engineering Cell Surface Glycans with Carbohydrate Enantiomers to Alter Bacterial Binding and Adhesion

2017 ◽  
Vol 2 (28) ◽  
pp. 8865-8869 ◽  
Author(s):  
Madhuri Gade ◽  
Preeti Madhukar Chaudhary ◽  
Hirekodathakallu V. Thulasiram ◽  
Raghavendra Kikkeri
Keyword(s):  
Cell Surface ◽  
Bacterial Binding ◽  
Cell Surface Glycans

Integrin subunits (beta)1C-1 and (beta)1C-2 expressed in GD25T cells are retained and degraded intracellularly rather than localised to the cell surface

1999 ◽  
Vol 112 (24) ◽  
pp. 4751-4761
Author(s):  
G. Svineng ◽  
S. Johansson
Keyword(s):  
Cell Surface ◽  
Focal Adhesion ◽  
Northern Blot Analysis ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Deficient Mouse ◽  
Normal Cells ◽  
Alpha Subunits ◽  
Metabolic Labelling ◽  
Adhesion Sites

We have previously identified the integrin (beta)1C-2 and characterised the distribution of (beta)1C-1 and (beta)1C-2 transcripts in various cell lines and normal cells. In this study we have investigated the expression of the two (beta)1C-variants in integrin (beta)1 deficient mouse GD25T cells. After stable transfection of the GD25T cells with cDNAs coding for (beta)1A, (beta)1C-1 and (beta)1C-2, the cell surface expression of the (beta)1C-1 and (beta)1C-2 variants was found to be very low while the (beta)1A variant was expressed at high levels. Northern blot analysis showed that the level of (beta)1-transcript in the (beta)1C-1 and (beta)1C-2 clones was equal or higher than in the (beta)1A clones. Metabolic labelling and deglycosylation by endoglycosidase H treatment clearly demonstrated that the majority of the (beta)1C-1 and (beta)1C-2 chains did not become maturely glycosylated, nor did they dimerize with (alpha) subunits. After 20 hours of chase, the labelled (beta)1C-1 and (beta)1C-2 chains had been gradually degraded, whereas immature (beta)1A was converted into the maturely glycosylated form during the same period of time. Immunostaining showed intracellular (beta)1 localisation in the (beta)1C-1 and (beta)1C-2 expressing clones, while in the (beta)1A expressing clones the (beta)1 chains were mainly localised to focal adhesion sites and along fibronectin fibres. Taken together, we have shown that expression of both integrin (beta)1C-1 and (beta)1C-2 in GD25T cells result in very low cell surface expression compared with the normal (beta)1A isoform. Instead, both (beta)1C-1 and (beta)1C-2 chains remain in the endoplasmic reticulum until they are intracellularly degraded.

scholarly journals PDMS Nano-Modified Scaffolds for Improvement of Stem Cells Proliferation and Differentiation in Microfluidic Platform

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 668 ◽  
Author(s):  
Hadi Hashemzadeh ◽  
Abdollah Allahverdi ◽  
Mosslim Sedghi ◽  
Zahra Vaezi ◽  
Tahereh Tohidi Moghadam ◽  
...  
Keyword(s):  
Stem Cells ◽  
Surface Roughness ◽  
Stem Cell ◽  
Cell Surface ◽  
Superparamagnetic Iron Oxide ◽  
Fold Increase ◽  
Stem Cell Differentiation ◽  
Gold Nanowires ◽  
Cell Substrate ◽  
Proliferation And Differentiation

Microfluidics cell-based assays require strong cell-substrate adhesion for cell viability, proliferation, and differentiation. The intrinsic properties of PDMS, a commonly used polymer in microfluidics systems, regarding cell-substrate interactions have limited its application for microfluidics cell-based assays. Various attempts by previous researchers, such as chemical modification, plasma-treatment, and protein-coating of PDMS revealed some improvements. These strategies are often reversible, time-consuming, short-lived with either cell aggregates formation, not cost-effective as well as not user- and eco-friendly too. To address these challenges, cell-surface interaction has been tuned by the modification of PDMS doped with different biocompatible nanomaterials. Gold nanowires (AuNWs), superparamagnetic iron oxide nanoparticles (SPIONs), graphene oxide sheets (GO), and graphene quantum dot (GQD) have already been coupled to PDMS as an alternative biomaterial enabling easy and straightforward integration during microfluidic fabrication. The synthesized nanoparticles were characterized by corresponding methods. Physical cues of the nanostructured substrates such as Young’s modulus, surface roughness, and nanotopology have been carried out using atomic force microscopy (AFM). Initial biocompatibility assessment of the nanocomposites using human amniotic mesenchymal stem cells (hAMSCs) showed comparable cell viabilities among all nanostructured PDMS composites. Finally, osteogenic stem cell differentiation demonstrated an improved differentiation rate inside microfluidic devices. The results revealed that the presence of nanomaterials affected a 5- to 10-fold increase in surface roughness. In addition, the results showed enhancement of cell proliferation from 30% (pristine PDMS) to 85% (nano-modified scaffolds containing AuNWs and SPIONs), calcification from 60% (pristine PDMS) to 95% (PDMS/AuNWs), and cell surface marker expression from 40% in PDMS to 77% in SPION- and AuNWs-PDMS scaffolds at 14 day. Our results suggest that nanostructured composites have a very high potential for stem cell studies and future therapies.

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