Selective recognition of acetate ion based on fluorescence enhancement chemosensor

Fluorescence study of the complexation between uranyl salophen (L) and some common anions in acetonitrile–water (90:10, v/v) solution showed a tendency of L toward acetate ion (AcO^?). The fluorescence enhancement of L is attributed to a 1:1 complex formation between L and acetate ion which was utilized as the basis for the selective detection of AcO^?. The association constant of the 1:1 complex formation of L–AcO^? was calculated as 6.60 × 10⁶. The linear response range of the fluorescent chemosensor covers a AcO^? concentration range of 1.6 × 10^?7 to 2.5 × 10^?5 mol/L, with a detection limit of 2.5 × 10^?8 mol/L. L showed a selective and sensitive fluorescence enhancement response toward acetate ion over I₃^?, NO₃^?, CN^?, CO₃^2?, Br^?, Cl^?, F^?, H₂PO4^? and SO₄^2?, which was attributed to the higher stability of inorganic complex between acetate and L. Copyright © 2012 John Wiley & Sons, Ltd.     

In silico structural, functional and pathogenicity evaluation of a novel mutation: an overview of HSD3B2 gene mutations

Mutations of 3 beta hydroxysteroid dehydrogenase type II (HSD3B2) gene result in different clinical consequences. We explain a patient who demonstrated a salt wasting form of 3βHSD deficiency in infancy. Signs of hyponatremia and hyperkalemia were recognized in the infant with ambiguous genitalia and perineal hypospadias. The 46,XY male was genotyped by direct sequencing of HSD3B2 gene. Steroid profiles showed elevated concentration of 17 hydroxyprogesterone, and decrease in concentration of cortisol, and testosterone. Dehydroepiandrotone (DHEA) to androstenedione ratio had 6 fold increases. Direct sequencing of the patient revealed homozygous missense A82P mutation in exon 3. This mutation was confirmed by segregation analysis of the parents. Bioinformatic tools were used for in silico structural and functional analyses. Also, the pathological effect of the mutation was validated by different software. Alanine is a conserved amino acid in the membrane binding domain of the enzyme and proline substitution was predicted to destabilize the protein. This report may highlight the importance of the screening programs of the disorder in Iran.     

Chitosan prevents oxidative stress-induced amyloid β formation and cytotoxicity in NT2 neurons: involvement of transcription factors Nrf2 and NF-κB

Increased oxidative stress is a widely accepted factor in the development and progression of Alzheimer’s disease. Here, we introduce chitosan, an antioxidant oligosaccharide, as a protective agent against H₂O₂/FeSO₄-induced cell death in the NT2 neural cell line. Chitosan not only protects the neurons against cell death, as measured by MTT and caspase-3 activity, but also decreases amyloid β formation. NT2 neurons can be used to elucidate the relationship between oxidative stress and Aβ formation. We induced Aβ formation through oxidative stress in NT2 neurons and studied the effect of chitosan. We demonstrate that chitosan can be neuroprotective by suppressing Aβ formation. We further show that chitosan exerts its protective effect by up-regulation of HO-1, γ-GCS, Hsp-70, and Nrf2, while it inhibits activation of caspase-3 and NF-κB. Chitosan or chitosan derivatives have potential value as neuroprotective agents, particularly with regard to oxidative stress.     

Stabilization of transcription factor Nrf2 by tBHQ prevents oxidative stress-induced amyloid β formation in NT2N neurons

Alzheimer's disease (AD) a progressive neurodegenerative disorder of later life, is characterized by brain deposition of amyloid β-protein (Aβ) plaques, accumulation of intracellular neurofibrillatory tangles, synaptic loss and neuronal cell death. There is significant evidence that oxidative stress is a critical event in the pathogenesis of AD.     

Cytoprotective effects of antioxidant supplementation on mesenchymal stem cell therapy

Mesenchymal stem cells (MSCs) are earmarked as perfect candidates for cell therapy and tissue engineering due to their capacity to differentiate into different cell types. However, their potential for application in regenerative medicine declines when the levels of the reactive oxygen and nitrogen species (RONS) increase from the physiological levels, a phenomenon which is at least inevitable in ex vivo cultures and air-exposed damaged tissues. Increased levels of RONS can alter the patterns of osteogenic and adipogenic differentiation and inhibit proliferation, as well. Besides, oxidative stress enhances senescence and cell death, thus lowering the success rates of the MSC engraftment. Hence, in this review, we have selected some representatives of antioxidants and newly emerged nano antioxidants in three main categories, including chemical compounds, biometabolites, and protein precursors/proteins, which are proved to be effective in the treatment of MSCs. We will focus on how antioxidants can be applied to optimize the clinical usage of the MSCs and their associated signaling pathways. We have also reviewed several paralleled properties of some antioxidants and nano antioxidants which can be simultaneously used in real-time imaging, scaffolding techniques, and other applications in addition to their primary antioxidative function.     

Fractionation of Protein Hydrolysates of Fish Waste Using Membrane Ultrafiltration: Investigation of Antibacterial and Antioxidant Activities

Probiotics and Antimicrobial Proteins - In this study, yellowfin tuna (Thunnus albacores) viscera were hydrolyzed with protamex to obtain hydrolysate that is separated by a membrane ultrafiltration...     

Genetic counseling in carriers of reciprocal translocations involving two autosomes

One of the main genetic causes involve in the pathogenesis of recurrent abortion is parental chromosomal abnormalities. The central concept in genetic counseling with such families is to estimate the probability of recurrence of unfavorable pregnancy outcomes. The main questions that consultants usually ask are: Why did this happen? What is the risk to be done again?Our cases were two families with repeated miscarriage. The pedigrees were drawn, the chromosomes of couples were studied, and estimation for recurrent risk was done. We tried to answer those two main questions and clear the results for them.Parental chromosome abnormalities were founded after karyotyping with GTG technique at 450 band resolution, revealing 46 chromosomes with balanced translocation of autosomes in one of the partner in both families. Recurrent risk was estimated as “high” for their future pregnancies in each family.Couples in which one partner is the carrier of such balanced translocation have increased risks of infertility, recurrent abortion, and delivery of chromosomally abnormal offspring. Genetic counseling of such couples, therefore, presents a unique challenge and should be considered in dealing with such families.