Human mesenchymal stem cells inhibit the differentiation and effector functions of monocytes

Although monocytes represent an essential part of the host defence system, their accumulation and prolonged stimulation could be detrimental and may aggravate chronic inflammatory diseases. The present study has explored the less-understood immunomodulatory effects of mesenchymal stem cells on monocyte functions. Isolated purified human monocytes were co-cultured with human umbilical cord-derived mesenchymal stem cells under appropriate culture conditions to assess monocytes’ vital functions. Based on the surface marker analysis, mesenchymal stem cells halted monocyte differentiation into dendritic cells and macrophages and reduced their phagocytosis functions, which rendered an inability to stimulate T-cell proliferation. The present study confers that mesenchymal stem cells exerted potent immunosuppressive activity on monocyte functions such as differentiation, phagocytosis and Ag presentation; hence, they promise a potential therapeutic role in down-regulating the unwanted monocyte-mediated immune responses in the context of chronic inflammatory diseases.     

Improved angiogenic activity of endothelial progenitor cell in diabetic patients treated with insulin plus metformin

Type 2 diabetes (T2DM) is associated with an increased vascular disease. Moreover, endothelial progenitor cell (EPC) function is impaired in diabetic patients. Decreased EPC number plays a critical role in reduced endothelial repair and development of the vascular disorder. To determine the effect of metformin and insulin plus metformin on functional activity of EPCs, 130 participants were divided into three groups (group 1: healthy control; group 2: metformin; group 3: insulin plus metformin). The concentration of EPCs in the circulation was first quantified. Thereafter, circulating EPCs (cEPCs) were harvested and the biological features of these cells including proliferative, clonogenicity, tubulogenic, and migratory properties were analyzed after expansion. The serum protein levels of some proangiogenic factors were also measured. Our results showed greater numbers of cEPCs in control and in diabetic patients treated with insulin plus metformin than in metformin-treated patients. Insulin plus metformin therapy was associated with augmented proliferative, clonogenicity, migratory, and tubulogenic activity of cEPCs in patients with T2DM. Increased serum concentrations of angiogenic factors were also observed in patients treated with insulin plus metformin. Western blot analysis showed increased protein levels of pTie-2/Tie2 and Pakt/AKT in cEPCs harvested from T2DM, treated with insulin metformin plus. This study showed that treatment with insulin plus metformin in diabetic patients is associated with increased mobilization of EPCs into the circulation, with potential beneficial effect in vascular protection in diabetic patients.     

The Interaction between Factor H and Von Willebrand Factor

Complement factor H (fH) is a plasma protein that regulates activation of the alternative pathway, and mutations in fH are associated with a rare form of thrombotic microangiopathy (TMA), known as atypical hemolytic uremic syndrome (aHUS). A more common TMA is thrombotic thrombocytopenic purpura, which is caused by the lack of normal ADAMTS-13-mediated cleavage of von Willebrand factor (VWF). We investigated whether fH interacts with VWF and affects cleavage of VWF. We found that factor H binds to VWF in plasma, to plasma-purified VWF, and to recombinant A1 and A2 domains of VWF as detected by co-immunoprecipitation (co-IP) and surface plasmon resonance assays. Factor H enhanced ADAMTS-13-mediated cleavage of recombinant VWF-A2 as determined by quantifying the cleavage products using Western-blotting, enhanced cleavage of a commercially available fragment of VWF-A2 (FRETS-VWF73) as determined by fluorometric assay, and enhanced cleavage of ultralarge (UL) VWF under flow conditions as determined by cleavage of VWF-platelet strings attached to histamine stimulated endothelial cells. Using recombinant full-length and truncated fH molecules, we found that the presence of the C-terminal half of fH molecule is important for binding to VWF-A2 and for enhancing cleavage of the A2 domain by ADAMTS-13. We conclude that factor H binds to VWF and may modulate cleavage of VWF by ADAMTS-13.     

MicroRNAs in breast cancer: Roles,functions, and mechanism of actions

Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.     

Digestive amylase and pectinase activity in the larvae of alfalfa weevil Hypera postica (Coleoptera: Curculionidae)

The alfalfa weevil Hypera postica is a serious economic pest in most alfalfa grown in many countries worldwide. Digestive α-amylase and pectinase activities of larvae were investigated using general substrates. Midgut extracts from larvae showed an optimum activity for α-amylase against starch at acidic pH (pH 5.0). α-Amylase from larval midgut was more stable at mildly acidic pH (pH 5–6) than highly acidic and alkaline pH. The enzyme showed its maximum activity at 35°C. α-Amylase activity was significantly decreased in the presence of Ca²⁺, Mg²⁺ and sodium dodecylsulfate. On the contrary, K⁺ and Na⁺ did not significantly affect the enzyme activity. Zymogram analysis revealed the presence of one band of α-amylase activity in in-gel assays. Pectinase activity was assayed using agarose plate and colorimetric assays. Optimal pH for pectinase activity in the larval midgut was determined to be pH 5.0. Pectinase enzyme is more stable at pH 4.0–7.0 than highly acidic and alkaline pH. However, the enzyme was more stable at slightly acidic pH (pH 6.0) when incubation time increased. Maximum activity for the enzyme incubated at different temperatures was observed to be 40°C. Optimum pH activity for α-amylase and pectinase is not completely consistent with the pH prevailing in the larval midgut. This is the first report of the presence of pectinase activity in H. postica.     

Pyridine-Functionalized Fe3O4 Nanoparticles as a Novel Sorbent for the Preconcentration of Lead and Cadmium Ions in Tree Leaf as a Bioindicator of Urban Traffic Pollution

We have developed a facile and highly sensitive sorbent for cadmium and lead ions. It is based on Fe₃O₄ nanoparticles functionalized with a derivative of picoline and was characterized by scanning electron microscopy, differential thermographic analysis, and elemental analysis. The material can be applied to the preconcentration of lead and cadmium ions. Factors such as the type, concentration and volume of eluent, the pH of the sample solution, the time for extraction, and the volume of the sample were studied. The effects of a variety of ions on preconcentration and recovery of these ions were also investigated. The ions were determined by FAAS, and the limits of detection are <0.8 and <0.061???g?L^?1 for lead and cadmium, respectively. Recoveries and precisions are >98.0?% and <1.3?%, respectively. The method was validated by analyzing several certified leaf reference materials.     

Atrial fibrillation in β-thalassemia patients with a focus on the role of iron-overload and oxidative stress: A review

Cardiac complications including arrhythmia and especially atrial fibrillation (AF) are common causes of death in β-thalassemia patients. The main factor in the etiopathogenesis of these complications is iron overload, which results in increased oxidative stress. Although there is a known association between cardiac complications and iron overload in β-thalassemia patients, there is no comprehensive review on AF and excessive iron with a focus on oxidative stress in these patients. The aim of this article was to review the different aspects of AF in β-thalassemia patients with a focus on the prevention and treatment of AF by using iron chelators and/or anti-oxidants. AF in β-thalassemia patients is more common than in the general population. One of the most important causes of AF is cardiac iron overload and the harmful effects of increased oxidative stress. Iron-induced AF can be reversed by using an intensive iron chelation regimen. Based on a few experimental studies, the combination of iron chelators with some anti-oxidants, including NAC, vitamin C, and acetaminophen, can lead to improved cardiac protection. However, the effect of such combinations on cardiac arrhythmias should be further evaluated with animal and human studies.     

Retracted: Terbium-sensitized fluorescence method for the determination of dopamine in biological fluids and tablet formulation

The following article from Luminescence, Terbium‐sensitized fluorescence method for the determination of dopamine in biological fluids and tablet formulation by Vahid Shahinfard, Ali Ehsani, Vahid Panahi‐Azar, Negar Kabir Yousefi and Morteza Salek Jalali, published online on 12th January 2012 in Wiley Online Library ( www.onlinelibrary.wiley.com ), has been retracted by agreement between the authors, the journal Editor in Chief, Professor L. J. Kricka and Wiley‐Blackwell. The retraction has been agreed due to data in the article is not being reproducible. Copyright © 2012 John Wiley & Sons, Ltd.