CXCL4 Plasma Levels Are Not Associated with the Extent of Coronary Artery Disease or with Coronary Plaque Morphology

Background

CXCL4 is a platelet chemokine released at micromolar concentrations upon platelet activation. CXCL4 has been shown to promote atherogenesis by various mechanisms. However, data on CXCL4 plasma levels in patients with coronary artery disease are largely inconclusive. Computed coronary artery angiography (CCTA) represents an excellent tool to quantify and characterize coronary atherosclerotic plaques. We hypothesized that increased CXCL4 plasma levels may be associated with features of plaque instability resulting in adverse cardiovascular events. Specifically, we sought to determine whether CXCL4 levels are correlated with specific features of coronary artery disease including (1) plaque volume, (2) calcium score, (3) degree of stenosis, or (4) vascular remodeling.

Methods and Results

CXCL4 plasma levels were measured by ELISA in 217 patients undergoing CCTA for suspected CAD (mean age 64.2 ± 9.4 years, 107 (49.3%) male). Mean CXCL4 plasma levels were 12.5 ± 4.6 ng/mL. There was no significant correlation between CXCL4 levels and any clinical or demographic parameters including cardiovascular risk factors. CXCL4 plasma levels did not differ between patient with or without coronary artery disease (CAD: 12.5 ± 4.5 ng/ml, no CAD: 12.5 ± 4.8 ng/ml). Neither univariate nor multivariate analysis showed an association between CXCL4 levels and plaque volume, total calcium score, degree of stenosis, or vascular remodeling. Subgroup analysis of patients with CAD as confirmed by CCTA did not show any association of CXCL4 levels with the extent of CAD.

Conclusions

While CXCL4 may be present and active within the arterial wall, local increase of CXCL4 may not translate into systemically elevated CXCL4 levels. Further studies will have to test whether CXCL4 may still represent a suitable therapeutic target in human atherosclerosis.     

Light-directed synthesis of peptide nucleic acids (PNAs) chips

We report herein the light-directed synthesis of peptide nucleic acids (PNAs) microarray using PNA monomers protected by photolabile protecting groups and a maskless technique that uses a digital micromirror array system to form virtual masks. An ultraviolet image from the virtual mask was cast onto the active surface of a glass substrate, which was mounted in a flow cell reaction chamber connected to a peptide synthesizer. Light exposure was followed by automatic chemical coupling cycles and these steps were repeated with different virtual masks to grow the desired PNA probes in a selected pattern. In a preliminary experiment, an array of PNA probes with dimensions of 4.11 mm × 4.11 mm was generated on each slide. Each synthesis region in the final array measured 210 μm × 210 μm for a total of 256 sites. The center-to-center space was 260 μm. It was observed from the hybridization pattern of the fluorescently labeled oligonucleotide targets that the fluorescence intensities of the matched, and mismatched sequences showed substantial difference, demonstrating specificity in the identification of complementary sequences. This opens the way to exploit processes from the microelectronics industry for the fabrication of PNA microarrays with high densities.     

Demand for human allograft tissue in Canada

There is relatively little known about the demand for allograft tissues in Canada. The Canadian Council for Donation and Transplantation (CCDT) is a national advisory body that undertook a comprehensive “market survey” to estimate surgical demand for human allograft tissues in Canada. The report “Demand for Human Allograft Tissue in Canada” reflects survey results sent to 5 prominent User Groups. User Groups were identified as orthopaedic surgeons; neurosurgeons; corneal transplant surgeons; plastic surgeons, specifically those at Canadian Burn Units; and cardiac surgeons (adult and paediatric surgery). The demand for allograft grafts was determined and then extrapolated across the total User Group and then increases in allograft tissue use over the next 1–2 years across User Groups were predicted. The overall response rate for the survey was 21.4%. It varied from a low of 19.6% for the orthopaedic survey to a high of 40.5% for the corneal survey. The estimated current demand for allograft tissue in Canada ranges from a low of 34,442 grafts per year to a high of 62,098 grafts per year. The predicted increase in use of allograft tissue over the next 1–2 year period would suggest that annual demand could rise to somewhere in the range of 42,589–72,210 grafts. The highest rated preferences (98% and 94%) were for accredited and Canadian tissue banks, respectively. This study represents a key step in addressing the paucity of information concerning the demand for allograft tissue in Canada.     

Acceleration of antibacterial activity of curcumin loaded biopolymers against methicillin‐resistant Staphylococcus aureus: Synthesis,optimization, and evaluation

Curcumin is a polyphenolic molecule with antibacterial, antioxidant, anti‐inflammatory, and antimicrobial properties. This study aimed to prepare nanocurcumin by encapsulating in biopolymers to improve its stability, bioavailability, water‐solubility, antibacterial efficiency against methicillin‐resistant Staphylococcus aureus. Three effective variables of curcumin concentration, polymer concentration, and water volume on curcumin‐loaded polymer nanoparticles, were optimized. The average size of polyacrylic acid (PAA), polyvinyl alcohol (PVA), and polyethyleneimine (PEI) nanoparticles were obtained 75.2, 77.1, 86.4 nm, respectively. The nanoparticles had a spherical shape, a smooth and uniform surface morphology. The MIC of PAA, PVA, and PEI nanoparticles was 0.480, 0.390, and 0.340 mg/mL, respectively and the MIC of PAA, PVA, and PEI combined with methicillin was 0.330, 0.260, and 0.200 mg/mL, respectively. According to the results, curcumin‐loaded PEI nanoparticles had the highest inhibitory effect against methicillin‐resistant S. aureus among the synthesized nanoparticles. The results showed that solvent volume, polymer concentration and curcumin concentration had a significant effect on particle size. The inhibitory properties of curcumin nanoparticles significantly increased due to the smaller particle size and increased penetration into the bacterium. Curcumin‐loaded nanoparticles can be promising drug carriers for the treatment of infections, cancer, and other diseases.     

Protein Engineering of Chit42 Towards Improvement of Chitinase and Antifungal Activities

The antagonism of Trichoderma strains usually correlates with the secretion of fungal cell wall degrading enzymes such as chitinases. Chitinase Chit42 is believed to play an important role in the biocontrol activity of Trichoderma strains as a biocontrol agent against phytopathogenic fungi. Chit42 lacks a chitin-binding domain (ChBD) which is involved in its binding activity to insoluble chitin. In this study, a chimeric chitinase with improved enzyme activity was produced by fusing a ChBD from T. atroviride chitinase 18–10 to Chit42. The improved chitinase containing a ChBD displayed a 1.7-fold higher specific activity than chit42. This increase suggests that the ChBD provides a strong binding capacity to insoluble chitin. Moreover, Chit42-ChBD transformants showed higher antifungal activity towards seven phytopathogenic fungal species.     

Connector inversion probe technology: a powerful one-primer multiplex DNA amplification system for numerous scientific applications

We combined components of a previous assay referred to as Molecular Inversion Probe (MIP) with a complete gap filling strategy, creating a versatile powerful one-primer multiplex amplification system. As a proof-of-concept, this novel method, which employs a Connector Inversion Probe (CIPer), was tested as a genetic tool for pathogen diagnosis, typing, and antibiotic resistance screening with two distinct systems: i) a conserved sequence primer system for genotyping Human Papillomavirus (HPV), a cancer-associated viral agent and ii) screening for antibiotic resistance mutations in the bacterial pathogen Neisseria gonorrhoeae. We also discuss future applications and advances of the CIPer technology such as integration with digital amplification and next-generation sequencing methods. Furthermore, we introduce the concept of two-dimension informational barcodes, i.e. "multiplex multiplexing padlocks" (MMPs). For the readers' convenience, we also provide an on-line tutorial with user-interface software application CIP creator 1.0.1, for custom probe generation from virtually any new or established primer-pairs.     

Functionalized nanopipettes: toward label-free, single cell biosensors

Nanopipette technology has been proven to be a label-free biosensor capable of identifying DNA and proteins. The nanopipette can include specific recognition elements for analyte discrimination based on size, shape, and charge density. The fully electrical read-out and the ease and low-cost fabrication are unique features that give this technology an enormous potential. Unlike other biosensing platforms, nanopipettes can be precisely manipulated with submicron accuracy and used to study single cell dynamics. This review is focused on creative applications of nanopipette technology for biosensing. We highlight the potential of this technology with a particular attention to integration of this biosensor with single cell manipulation platforms.     

Echinococcus granulosus genotypes in livestock of Iran indicating high frequency of G1 genotype in camels

In this study, 112 Echinococcus granulosus isolates from different livestock of Iran were genotyped by PCR amplification of ribosomal DNA-internal transcribed spacer 1 (rDNA-ITS1) region followed by restriction fragment length polymorphism (RFLP) with the enzyme RsaI. The possibility of intra-genotype variation was also investigated using randomly amplified polymorphic DNA (RAPD) analysis. Isolates from sheep, goats, cattle and the majority of camels (12 of 18; 66.7%) were identified as the G1 genotype and a few camel isolates (6 of 18; 33.3%) belonged to the G6 genotype. Overall G1 and G6 genotypes were identified in 94.6% (106 of 112) and 5.3% (6 of 112) of all isolates, respectively. RAPD analysis based on 15 separate primers showed 7-14 bands of 200-3000 bp for strain G1. Considering each individual primer, no differences observed among isolates from different hosts and between livers and lungs. This study confirmed the existence of G1 and G6 genotypes in Iran. Moreover, G1 is much more prevalent even in camels, indicating the importance of sheep-dog cycle in public health. Studying intra-genotypic variation of E. granulosus warrants more research using other primers and methods.     

PathogenMIPer: a tool for the design of molecular inversion probes to detect multiple pathogens

Background  

Here we describe PathogenMIPer, a software program for designing molecular inversion probe (MIP) oligonucleotides for use in pathogen identification and detection. The software designs unique and specific oligonucleotide probes targeting microbial or other genomes. The tool tailors all probe sequence components (including target-specific sequences, barcode sequences, universal primers and restriction sites) and combines these components into ready-to-order probes for use in a MIP assay. The system can harness the genetic variability available in an entire genome in designing specific probes for the detection of multiple co-infections in a single tube using a MIP assay.