Stem Cells-Derived Extracellular Vesicles: Potential Therapeutics for Wound Healing in Chronic Inflammatory Skin Diseases

Endosome-derived small extracellular vesicles (EVs), often referred to as exosomes, are produced by almost all, if not all, cell types, and are critical for intercellular communication. They are composed of a lipid bilayer associated with membrane proteins and contain a payload of lipids, proteins and regulatory RNAs that depends on the parental cell physiological condition. By transferring their “cargo”, exosomes can modulate the phenotype of neighboring and distant cells. Stem cells (SC) were widely studied for therapeutic applications regarding their regenerative/reparative potential as well as their immunomodulatory properties. Whether from autologous or allogeneic source, SC beneficial effects in terms of repair and regeneration are largely attributed to their paracrine signaling notably through secreted EVs. Subsequently, SC-derived EVs have been investigated for the treatment of various diseases, including inflammatory skin disorders, and are today fast-track cell-free tools for regenerative/reparative strategies. Yet, their clinical application is still facing considerable challenges, including production and isolation procedures, and optimal cell source. Within the emerging concept of “allogeneic-driven benefit” for SC-based therapies, the use of EVs from allogeneic sources becomes the pragmatic choice although a universal allogeneic cell source is still needed. As a unique temporary organ that ensures the mutual coexistence of two allogeneic organisms, mother and fetus, the human placenta offers a persuasive allogeneic stem cell source for development of therapeutic EVs. Advancing cell-free therapeutics nurtures great hope and provides new perspectives for the development of safe and effective treatment in regenerative/reparative medicine and beyond. We will outline the current state of the art in regard of EVs, summarize their therapeutic potential in the context of skin inflammatory disorders, and discuss their translational advantages and hurdles.     

TaqMan probe real‐time polymerase chain reaction targeting the ATPase 6 gene for the detection of pork adulteration in meat and meatballs

We developed an assay for detecting pork adulteration in meat and meatballs using real‐time polymerase chain reaction involving specific primers and a TaqMan probe targeting the porcine mitochondrial (mt) ATPase 6 gene. We proved the specificity of the probe by showing no amplification from DNA isolated from six different meat‐providing species: cattle, dog, mouse, chicken, goat, and horse. On the contrary, DNA isolated from pork was positive for amplification, with a Ct (threshold cycle) of 18.69 using a standard amount of DNA template (50 ng). The presence of matrix and food processing steps in meatball sample had no influence on the specificity of the probe. The developed technique also has a good repeatability (CV, coefficient of variation = 3.86% for meat and 5.07% for meatballs), showing good linearity and sensitivity, with a limit of detection up to 5 pg of pork total DNA, which equivalent to approximately 6.8 copies of pork mtDNA. In addition, the analysis of spiked pork in beef meatballs showed that the method could determine up to 1% pork contamination. Moreover, the system was successfully applied to detect pork adulteration in commercial meatballs by detecting the presence of pork DNA in two samples.     

Characterization of filamentous fungi isolated from Moroccan olive and olive cake: toxinogenic potential of Aspergillus strains

During the 2003 and 2004 olive oil production campaigns in Morocco, 136 samples from spoiled olive and olive cake were analyzed and 285 strains were isolated in pure culture. Strains included 167 mesophilic strains belonging to ten genera: Penicillium, Aspergillus, Geotrichum, Mucor, Rhizopus, Trichoderma, Alternaria, Acremonium, Humicola, Ulocladium as well as 118 thermophilic strains isolated in 2003 and 2004, mainly belonging to six species: Aspergillus fumigatus, Paecilomyces variotii, Mucor pusillus, Thermomyces lanuginosus, Humicola grisea, and Thermoascus aurantiacus. Penicillium and Aspergillus, respectively, 32.3 and 26.9% of total isolates represented the majority of mesophilic fungi isolated. When considering total strains (including thermotolerant strains) Aspergillus were the predominant strains isolated; follow-up studies on mycotoxins therefore focused primarily on aflatoxins (AFs) and ochratoxin A (OTA) from the latter strains. All isolated Aspergillus flavus strains (9) and Aspergillus niger strains (36) were studied in order to evaluate their capacity to produce AFs and OTA, respectively, when grown on starch-based culture media. Seven of the nine tested A. flavus strains isolated from olive and olive cake produced AF B1 at concentrations between 48 and 95 microg/kg of dry rice weight. As for the A. niger strains, 27 of the 36 strains produced OTA.     

Effects of freezing treatments on the fermentative activity and gluten network integrity of sweet dough

The effect of freezing treatments on sweet dough was studied. The dough was frozen at ?20 °C, ?30 °C and ?40 °C in air-blast freezer cabinet and by immersion in liquid nitrogen. The yeast viability, gassing power, dough volume and dough network integrity from fresh and thawed sweet doughs were assessed. The results showed that both parameters depend on the freezing rate, which controls ice crystals size and location. Dough volume loss after freezing was attributed to reduced yeast fermentative activity and gluten network alteration in frozen dough. Fermentative activity reduced significantly in frozen dough using liquid nitrogen, causing 70% decrease on yeast population. Gluten integrity seemed to be affected by slow freezing treatment, i.e. ?20 °C and ?30 °C. Gas loss was also evaluated as a decrease of 25% ± 2 in dough volume. A correlation was observed between the freezing rate and osmotic pressure effects which influence strongly the yeast viability.     

Discrete fractional Fourier transform based on the eigenvectors of tridiagonal and nearly tridiagonal matrices

The recent emergence of the discrete fractional Fourier transform (DFRFT) has caused a revived interest in the eigenanalysis of the discrete Fourier transform (DFT) matrix F with the objective of generating orthonormal Hermite–Gaussian-like eigenvectors. The Grünbaum tridiagonal matrix T—which commutes with matrix F—has only one repeated eigenvalue with multiplicity two and simple remaining eigenvalues. A detailed eigendecomposition of matrix T is performed with the objective of deriving two orthonormal eigenvectors—common to both the F and T matrices—pertaining to the repeated eigenvalue of T. The nearly tridiagonal matrix S first introduced by Dickinson and Steiglitz and later studied by Candan et al.—which commutes with matrix F—is rigorously proved to reduce to a 2×2 block diagonal form by means of a similarity transformation defined in terms of an involutary matrix P. Moreover explicit expressions are derived for the elements of the two tridiagonal submatrices forming the two diagonal blocks in order to circumvent the need for performing two matrix multiplications. Although matrix T has the merit of being tridiagonal and does not need the tridiagonalization step as matrix S, the simulation results show that the eigenvectors of matrix S better approximate samples of the Hermite–Gaussian functions than those of matrix T and moreover they have a shorter computation time due to the block diagonalization result. Consequently they can serve as a better basis for developing the DFRFT.     

Functional role of bioactive peptides with special reference to cheeses

Growing perception about diet in relation to health has extended the necessity to explore the biologically active components present in native foods. In this review, bioactive peptides released from cheeses that may have important physiological functions are discussed. Bioactive encrypted peptides can be generated from precursor milk proteins during food processing via enzymatic hydrolysis and fermentation. Generally, biofunctionalities of peptides are latent within precursor proteins. Bioactive peptides liberated from cheeses exhibit numerous potential therapeutic roles: for example, angiotensinogen‐converting enzyme (ACE) inhibition, antioxidant, anti‐thrombotic, anti‐microbial, anti‐cancer and anti‐inflammatory. This article critically focuses on the functional roles of bioactive peptides derived from different cheeses.     

Mucoadhesive delivery systems. II. Formulation and in-vitro/in-vivo evaluation of buccal mucoadhesive tablets containing water-soluble drugs

From the previous work (Part I), mucoadhesive formulae containing 5% CP/65% HPMC/30% lactose and 2% PC/68% HPMC/30% mannitol as well as formulae based on sodium carboxymethyl cellulose (SCMC) were selected. Medicated tablets were prepared using diltiazem hydrochloride (DZ) and metclopramide hydrochloride (MP) in two different doses (30 and 60 mg). The effect of drug and dose on the mucoadhesive properties and in-vitro drug release was evaluated. All formulae produced extended drug release (over 8 to 12 h). Polyacrylic acid based matrices (PAA) showed Fickian's diffusion release pattern for both drugs. SCMC ensured zero-order release for DZ, which deviated to anomalous behavior in case of MP. Doubling the dose significantly reduced the bioadhesion strength (p<0.05) with a slight improvement in drug release rate. The formulation of bilayer tablets containing drug-free layer and medicated layer enhanced the drug release without affecting the bioadhesive performance. The bilayer tablet formulated with 2% PC/68% HPMC/30% mannitol (PC2) was selected for studying the in-vivo metoclopramide release in four healthy volunteers. The tablet ensured controlled drug release for 12 h, in addition, good correlation (r=0.9398) was observed between in-vitro and in-vivo data. The effect of ageing on selected formulae containing DZ and MP, respectively, was studied. Storage at 40 degrees C and 75% relative humidity for 6 months didn't influence the mucoadhesive performance, however, an enhanced released rate was observed.     

Numerical Simulation of Taylor–Couette Flows with Rotating Outer Wall Using a Hybrid Spectral/Finite Element Method

Theoretical Foundations of Chemical Engineering - Taylor–Couette flow between independently rotating cylinders with a relatively small aspect ratio Γ = 2.4 has been investigated...     

Re-ranking Person Re-identification using Attributes Learning

Neural Computing and Applications - Person re-identification (Re-ID) across multi-camera views remains a very challenging task. In fact, the use of global convolutional neural network (CNN)...