Enhanced chondrogenic differentiation of dental pulp-derived mesenchymal stem cells in 3D pellet culture system: effect of mimicking hypoxia

High incidence of articular cartilage defects resulting from age-related degeneration or trauma injuries is a major problem worldwide. Limited self-regeneration ability of cartilage often leads to inappropriate biochemistry and structure of healed tissue. Considering Impairments of traditional treatments, cell-based therapies are promising. The rapid ex vivo expansion and chondrogenic differentiation capability make dental pulp stem cells (DPSCs) a favorable cell type for therapeutic application, however strategies in order to efficient cartilage tissue-like production are imperative. In the present study the potential role of hypoxia mimicking agent, cobalt chloride (CoCl2), on chondrogenic differentiation of human DPSCs was surveyed. Cell viability assay used to obtain the optimum dose and exposure time of CoCl2. DPSCs were differentiated in pellet culture system after CoCl2 pretreatment. Chondrogenic differentiation efficiency was evaluated by histological and immunohistological analyses. The results showed that CoCl2 led to increased pellet size, integrity and matrix deposition with organizations more resembled typical cartilage lacuna structure. Furthermore, CoCl2 could improve differentiation by elevated chondrogenic markers, glycosaminoglycans (GAGs) and collagen II expression. CoCl2 pretreatment mitigated hypertrophy, as well, which was reflected in decreased collagen X expression. Alkaline phosphatase (ALP) specific activity did not change significantly by CoCl2 preconditioning. Based on current study hypoxia mimicking agent, CoCl2, could be suggested to promote DPSCs chondrogenic differentiation.     

<Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> as a Probiotic Potential from Kouzeh Cheese (Traditional Iranian Cheese) and Its Antimicrobial Activity

The aim of this study is to isolate and identify Lactobacillus plantarum isolates from traditional cheese, Kouzeh, and evaluate their antimicrobial activity against some food pathogens. In total, 56 lactic acid bacteria were isolated by morphological and biochemical methods, 12 of which were identified as Lactobacillus plantarum by biochemical method and 11 were confirmed by molecular method. For analyzing the antimicrobial activity of these isolates properly, diffusion method was performed. The isolates were identified by 318 bp band dedicated for L. plantarum. The isolated L. plantarum represented an inhibitory activity against four of the pathogenic bacteria and showed different inhibition halos against each other. The larger halos were observed against Staphylococcus aureus and Staphylococcus epidermidis (15 ± 0.3 and 14.8 ± 0.7 mm, respectively). The inhibition halo of Escherichia coli was smaller than that of other pathogen and some L. plantarum did not show any inhibitory activity against E. coli, which were resistant to antimicrobial compounds produced by L. plantarum. The isolated L. plantarum isolates with the antimicrobial activity in this study had strong probiotic properties. These results indicated the nutritional value of Kouzeh cheese and usage of the isolated isolates as probiotic strains.     

PCR-based detection and eradication of mycoplasmal infections from various mammalian cell lines: a local experience

A total of 200 cell lines including different human, monkey, mice, hamster and rat cell types were examined for mycoplasma infection status. PCR assay using generic-specific universal primers showed that 40 (20%) of the cell lines are contaminated with mycoplasma. Employment of species-specific primers within these infected cell lines revealed infection with M. hyorhinis (42.5%), M. fermentas (37.5%), M. arginini (37.5%), M. orale (12.5%) and A. laidlawii (7.5%). A number of the cultures were coinfected with 2 or 3 different species. Contaminated samples were treated with BM-Cyclin, Ciprofloxacin and mycoplasma removal agent (MRA). Mycoplasma eradication was subsequently checked by PCR following 2 weeks continuous culture of treated cells in antibiotic free culture medium. Mycoplasmal infections were eradicated in 100, 70 and 42% of infected cell lines when the samples were treated with BM-Cyclin, MRA and Ciprofloxacin, respectively. However, 12% (BM-Cyclin), 62.5% (MRA) and 82.5% (Ciprofloxacin) of mycoplasma regrowth was observed 4 months after the treatment. Notably, the risk of spontaneous culture death was 17.5, 12.5 and 0% for BM-Cyclin, MRA and Ciprofloxacin, respectively.     

Suitability evaluation of some specific crops in Souma area (Iran), using Cervatana and Almagra models

In the present study Cervatana and Almagra models from decision support system, MicroLEIS DSS, were applied to segregation of arable land surfaces from the marginal ones and suitability evaluation of wheat (Triticum aestivum), maize (Zea mays) and alfalfa (Medicago sativa) in Souma area with approximately 4100 ha extension in West Azarbaijan. Obtained results from both models are presented and discussed in this research work. Soil morphological and analytical data were collected from 35 soil profiles, representative of the study area and stored in SDBm plus database. The control or vertical section of soil for applying and running the models for annual selected crops, was calculated by soil layer generator 0.0–50 cm in depth, or between the surface and the limit of useful depth when the latter is between 0.0 and 50 cm. According to results, 80.49% of the total area was good capable for agricultural uses and 19.51% must be reforested and not dedicated to agriculture. The lands with good capability for agricultural uses is classified as highly suitable area (S2) for wheat, maize and alfalfa, but results in 822 ha for maize and in 126 ha for alfalfa refers to an excellent suitable (S1) and moderately suitable (S3) classes respectively. The most important limitation factors are soil texture and carbonate alone or together and maize — wheat — alfalfa can be selected as the best crop rotation. A simple map subsystem (ArcView GIS) was used for basic data and models result demonstration on a map.     

An improved method to assess torsional properties of rodent long bones

Torsion is an important testing modality commonly used to calculate structural properties of long bones. However, the effects of size and geometry must be excluded from the overall structural response in order to compare material properties of bones of different size, age and species. We have developed a new method to analyze torsional properties of bones using actual cross-sectional information and length-wise geometrical variations obtained by micro-computed topographic (μCT) imaging. The proposed method was first validated by manufacturing three rat femurs through rapid prototyping using a plastic with known material properties. The observed variations in calculated torsional shear modulus of the hollow elliptical model of mid-shaft cross-section (Ekeland et al.), multi-prismatic model of five true cross-sections (Levenston et al.) and multi-slice model presented in this study were 96%, ?7% and 6% from the actual properties of the plastic, respectively. Subsequently, we used this method to derive relationships expressing torsional properties of rat cortical bone as a function of μCT-based bone volume fraction or apparent density over a range of normal and pathologic bone densities. Results indicate that a regression model of shear modulus or shear strength and bone volume fraction or apparent density described at least 81% of the variation in torsional properties of normal and pathologic bones. Coupled with the structural rigidity analysis technique introduced by the authors, the relationships reported here can provide a non-invasive tool to assess fracture risk in bones affected by pathologies and/or treatment options.     

Ultrasensitivity in multisite phosphorylation of membrane-anchored proteins

Cellular signaling is initially confined to the plasma membrane, where the cytoplasmic tails of surface receptors and other membrane-anchored proteins are phosphorylated in response to ligand binding. These proteins often contain multiple phosphorylation sites that are regulated by membrane-confined enzymes. Phosphorylation of these proteins is thought to be tightly regulated, because they initiate and regulate signaling cascades leading to cellular activation, yet how their phosphorylation is regulated is poorly understood. Ultrasensitive or switchlike responses in their phosphorylation state are not expected because the modifying enzymes are in excess. Here, we describe a novel mechanism of ultrasensitivity exhibited by multisite membrane-anchored proteins, but not cytosolic proteins, even when enzymes are in excess. The mechanism underlying this concentration-independent ultrasensitivity is the local saturation of a single enzyme by multiple sites on the substrate. Local saturation is a passive process arising from slow membrane diffusion, steric hindrances, and multiple sites, and therefore may be widely applicable. Critical to this ultrasensitivity is the brief enzymatic inactivation that follows substrate modification. Computations are presented using ordinary differential equations and stochastic spatial simulations. We propose a new role, to our knowledge, for multisite membrane-anchored proteins, discuss experiments that can be used to probe the model, and relate our findings to previous theoretical work.     

Mixture of fibroblast, epithelial and endothelial cells conditioned media induce monocyte-derived dendritic cell maturation

Fully matured DCs with large amount cytoplasm and copious dendritic projections were visible at the end of culturing period in the presence of MCM, TNF-α and poly (I:C), with or without FEECM. Thus, DCs generated with these maturation factors are nonadherent and have typical satellite morphology. Flow cytometric analysis using anti-CD14, -CD80, -CD86, -HLA-DR and -CD83 revealed that expression of CD14 is decreased in particular in FEECM treated DCs, on day 5 and expression of CD80, CD86 and HLA-DR was the higher when FEECM are added to maturation factor. Functionally, when DCs matured in the presence of FEECM elicited stronger MLR, reduced phagocytic activity. These results support the use of the FEECM with MCM, TNF-α and poly (I–C) as maturation factor in DC generation that could result in functionally mature monocyte-derived DCs in comparison to either alone.     

Serum Arsenic and Lipid Peroxidation Levels in Patients with Multiple Sclerosis

Oxidative stress plays a crucial role in the pathogenesis of multiple sclerosis (MS). Previous studies have shown that oxidative stress is one of the main underlying mechanisms of arsenic-induced cellular damage. The aim of this study was to assess the serum levels of arsenic and its relationship with lipid peroxidation in MS patients from Tabriz, as the third polluted city of Iran. The study population included 38 MS female patients and 38 age-matched healthy controls. Serum malondialdehyde (MDA) and arsenic levels were measured using thiobarbituric acid reactive substances (TBARS) assay and electrothermal atomic absorption spectrometry, respectively. The results showed that the arsenic (P?<?0.01) and MDA (P?=?0.03) levels were significantly higher in patients with MS than those in control. Moreover, serum levels of arsenic and MDA were positively correlated in MS patients. The elevated levels of serum arsenic might explain the increased oxidative stress in MS patients. We suggest that high arsenic levels in serum may lead to MS development, and therefore, exposure to this metal should be limited.