Nrf-2 overexpression in mesenchymal stem cells reduces oxidative stress-induced apoptosis and cytotoxicity

The most prominent capabilities of mesenchymal stem cells (MCSs) which make them promising for therapeutic applications are their capacity to endure and implant in the target tissue. However, the therapeutic applications of these cells are limited due to their early death within the first few days following transplantation. Therefore, to improve cell therapy efficacy, it is necessary to manipulate MSCs to resist severe stresses imposed by microenvironment. In this study, we manipulated MSCs to express a cytoprotective factor, nuclear factor erythroid-2 related factor 2 (Nrf2) to address this issue. Full-length human Nrf2 cDNA was isolated and TOPO cloned into TOPO cloning vector and then transferred to gateway adapted adenovirus expression vector by LR recombination reaction. Afterwards, the Nrf2 bearing recombinant virus was prepared in appropriate mammalian cell line and used to infect MSCs. The viability and apoptosis of the Nrf2 expressing MSCs were evaluated following hypoxic and oxidative stress conditions. Transient expression of Nrf2 by MSCs protected them against cell death and the apoptosis triggered by hypoxic and oxidative stress conditions. Nrf2 also enhanced the activity of SOD and HO-1. These findings could be used as a strategy for prevention of graft cell death in MSC-based cell therapy. It also indicates that management of cellular stress responses can be used for practical applications.     

A randomized, double-blind, placebo-controlled, clinical dose–response trial of an extract of Baptisia, Echinacea and Thuja for the treatment of patients with common cold

The aim of this study was to verify the efficacy and safety of an herbal medication containing an extract of a mixture of Baptisiae tinctoriae radix, Echinaceae pallidae/purpureae radix and Thujae occidentalis herba (SB-TOX) in the treatment of upper respiratory tract infections (URIs), and to test whether SB-TOX's clinical efficacy is dose dependent. A total of 91 adults (mean age 42.1±13.0 years) were randomised to receive 19.2 mg of SB-TOX (n=31), 9.6 mg SB-TOX (n=29) or placebo (n=31) three times daily for 3–12 days. Since a “running nose” is the main symptom of a common cold, the total number of facial tissues used throughout the clinical duration of their cold was the primary efficacy parameter. In the intention-to-treat analysis, this total number of tissues decreased with increasing extract dose. The slope across groups according to the Jonckheere test was significant (p=0.0259). In the high-dose group, the standardised effect size Δ/SD was 0.46 compared with placebo. Time to relevant improvement in cold symptoms (measured as the time until less than 30 tissues per day were used) was 1.1 days (95% CI 0.52; 1.67), 0.76 days (95% CI 0.28; 1.24) and 0.52 days (95% CI 0.22; 0.82) in the placebo, low-dose and high-dose groups, respectively (p_LogRank=0.0175). No adverse events were reported. This study demonstrates the efficacy and safety of SB-TOX in the treatment of URIs, and that its efficacy is dose dependent.     

Dual chamber pacing in a patient of hypertrophic cardiomyopathy with failure to wean from mechanical ventilator

We discuss the case of a 63 years old female who required repeated intubation due to recurrent pulmonary edema. She was found to have hypertrophic cardiomyopathy with a gradient of 82 mmHg across the left ventricular outflow tract. Initially adequate rate control and treatment with negative inotropes did not help her condition. Finally a dual chamber pacemaker implantation and atrioventricular node modification lead to successful extubation.     

PCR Analysis of the Tri13 gene to Determine the Genetic Potential of Fusarium graminearum Isolates from Iran to Produce Nivalenol and Deoxynivalenol

Fusarium graminearum trichothecene producing isolates can be broadly divided into two chemotypes based on the production of the 8- ketotrichothecenes deoxynivalenol (DON) and nivalenol (NIV). Functional Tri13 gene required for the production of NIV and 4- acetyl NIV, whereas in the isolates producing DON and its acetylated derivates, this gene is nonfunctional. In this study, a total of 57 isolates from different fields of Mazandaran province, Iran were identified as F. graminearum using classical methods and species specific primers. In order to assess the potential of isolates to produce NIV or DON, we used PCR to determine whether isolates carried a functional or nonfunctional Tri13 gene. Out of the 57 tested F. graminearum isolates with Tri13 PCR assays, 46 yielded an amplicon similar to the size predicted for nivalenol production, while 11 yielded an amplicon similar to the size predicted for deoxynivalenol production. From regions where more than one F. graminearum isolate was obtained, isolates were not exclusively of a single chemotype. It seems that genetic diversity among the isolates has relation with geographical region and wheat cultivar. The assay can provide information about the distribution of Tri13 haplotype that can be used in tracing of trichothecene contaminated samples.     

Plant peptides and peptidomics

Extracellular plant peptides perform a large variety of functions, including signalling and defence. Intracellular peptides often have physiological functions or may merely be the products of general proteolysis. Plant peptides have been identified and, in part, functionally characterized through biochemical and genetic studies, which are lengthy and in some cases impractical. Peptidomics is a branch of proteomics that has been developed over the last 5 years, and has been used mainly to study neuropeptides in animals and the degradome of proteases. Peptidomics is a fast, efficient methodology that can detect minute and transient amounts of peptides and identify their post-translational modifications. This review describes known plant peptides and introduces the use of peptidomics for the detection of novel plant peptides.     

Molecular dynamics simulation of the cooperative adsorption of barley lipid transfer protein and cis-isocohumulone at the vacuum-water interface

Molecular dynamic simulations have been carried out on systems containing a mixture of barley lipid transfer protein (LTP) and cis-isocohumulone (a hop derived iso-alpha-acid) in one of its enol forms, in bulk water and at the vacuum-water interface. In solution, the cis-isocohumulone molecules bind to the surface of the LTP molecule. The mechanism of binding appears to be purely hydrophobic in nature via desolvation of the protein surface. Binding of hop acids to the LTP leads to a small change in the 3-D conformation of the protein, but no change in the proportion of secondary structure present in helices, even though there is a significant degree of hop acid binding to the helical regions. At the vacuum-water interface, cis-isocohumulone shows a high surface activity and adsorbs rapidly at the interface. LTP then shows a preference to bind to the preadsorbed hop acid layer at the interface rather than to the bare water-vacuum interface. The free energy of adsorption of LTP at the hop-vacuum-water interface is more favorable than for adsorption at the vacuum-water interface. Our results support the view that hop iso-alpha-acids promote beer foam stability by forming bridges between separate adsorbed protein molecules, thus strengthening the adsorbed protein layer and reducing foam breakdown by lamellar phase drainage. The results also suggest a second mechanism may also occur, whereby the concentration of protein at the interface is increased via enhanced protein adsorption to adsorbed hop acid layers. This too would increase foam stability through its effect on the stabilizing protein layer around the foam bubbles.     

Sulphur protects mustard (<Emphasis Type="Italic">Brassica campestris</Emphasis> L.) from cadmium toxicity by improving leaf ascorbate and glutathione

In a pot-soil culture ameliorative effect of sulphur (S) (0 or 40 mg S kg⁻¹ soil) on cadmium (Cd) (0, 25, 50 and 100 mg Cd kg⁻¹ soil)-induced growth inhibition and oxidative stress in mustard (Brassica campestris L.) cultivar Pusa Gold was studied. Cadmium at 100 mg kg⁻¹ soil caused maximum increase in the contents of Cd and thiobarbituric acid reactive substances (TBARS) in leaves. Maximum reductions in growth (plant dry mass, leaf area), chlorophyll content, net photosynthetic rate (P_N) and the contents of ascorbate (AsA), glutathione (GSH) were observed with 100 mg Cd kg⁻¹ soil compared to control. The application of S helped in reducing Cd toxicity, which was greater for 25 and 50 mg Cd kg⁻¹ soil) compared to 100 mg Cd kg⁻¹ soil. Addition of S to Cd-treated plants showed decrease in Cd and TBARS content in leaves and restoration of growth and photosynthesis through increase in the contents of AsA and GSH. Net photosynthetic rate and plant dry mass were strongly and positively correlated with the contents of AsA and GSH. It is suggested that S may ameliorate Cd toxicity and protects growth and photosynthesis of mustard involving AsA and GSH.     

Use of hydrophilic natural gums in formulation of sustained-release matrix tablets of tramadol hydrochloride

The objective of this work was to develop matrix sustained-release tablets of highly water-soluble tramadol HCl using natural gums (xanthan [X gum] and guar [G gum]) as cost-effective, nontoxic, easily available, and suitable hydrophilic matrix systems compared with the extensively investigated hydrophilic matrices (ie, hydroxypropyl methylcellulose [HPMC]/carboxymethyl cellulose [CMC] with respect to in vitro drug release rate) and hydration rate of the polymers. Matrix tablets of tramadol (dose 100 mg) were produced by direct compression method. Different ratios, of 100∶0, 80∶20, 60∶40, 20∶80, 0∶100 of G gum (or X):HPMC, X gum:G gum, and triple mixture of these polymers (G gum, X gum, HPMC) were applied. After evaluation of physical characteristics of tablets, the dissolution test was, performed in the phosphate buffer media (pH 7.4) up to 8 hours. Tablets with only X had the highest mean dissolution time (MDT), the least dissolution efficiency (DE₈%), and released the drug following a zero-order model via swelling, diffusion, and erosion mechanisms. Guar gum alone could not efficiently control the drug release, while X and all combinations of natural gums with HPMC could retard tramadol HCl release. However, according to the similarity factor (f ₂), pure HPMC and H₈G₂ were the most similar formulations to Topalgic-LP as the reference standard. Published: March 17, 2006     

Surface expression of CXCR4 in unrestricted somatic stem cells and its regulation by growth factors

Umbilical cord blood‐derived USSCs (unrestricted somatic stem cells) have recently been considered as a potential source for stem cell therapy and transplantation due to their characteristics such as easy accessibility, low immunogenicity, self‐renewing and multilineage differentiation potential. Stem cell homing is a key factor in successful transplantation, which is regulated by CXCR4 in stem cells. In this study, we evaluated the expression of CXCR4 in USSCs different passages. Moreover, the effect of VEGF (vascular endothelial growth factor) and IGF‐1 (insulin‐like growth factor 1) on its expression was assessed. It was shown that the expression of CXCR4 in USSCs decreased with the increase in passage number. It was also revealed that VEGF increased surface expression and mRNA level of CXCR4 in USSCs, while IGF‐1 decreased its expression. When VEGF and IGF‐1 were administered simultaneously, CXCR4 expression was increased, but the expression level was less than VEGF alone. Finally, it was shown that over‐expression of CXCR4 enhanced the migratory capacity of USSCs. The increase of CXCR4 expression, here caused by VEGF in USSCs, can improve the efficacy of stem cell therapy and transplantation after long‐term culture of stem cells before clinical use.