Mutational Analysis of the VPREB1 Gene of Pre-BCR Complex in a Cohort of Sporadic Pediatric Patients With B-Cell Acute Lymphoblastic Leukemia.

During bone marrow B-cell development, the pre-B-cell receptor is formed by the association of the immunoglobulin heavy chain with a surrogate light chain, which is encoded by the VPREB1, and λ5 genes. It is known that pre-BCR signaling signifies a critical checkpoint at the pre-B-cell stage. Thus, failure pre-BCR signaling is proposed as a critical factor for the development of B-cell acute lymphoblastic leukemia (B-ALL). B­ALL is the most common pediatric cancer and is one of the leading causes of death in children. Until now, several molecular analyses were performed for genomic alterations in B-ALL, but for genomic analysis of the VPREB1 gene and its rare variations, limited studies have been conducted. In this study, using polymerase chain reaction and direct sequencing of 88 pediatric patients with B-ALL, we investigated the genomic region of the VPREB1 gene to find sequence variations of this gene. Our study presented ten homozygous and heterozygous point mutations and heterozygous nucleotide deletions, in the VPREB1 gene in 36 boys and 32 girls' patients. Our Bioinformatics assay results presented that these variations may alter the RNA folding, protein structure, and therefore probable effect on the protein function. These results propose that nucleotide changes probably contribute to B-ALL pathogenesis.

Evaluating the additive effect of Persica and chlorhexidine mouthwashes on oral health status of children receiving chemotherapy for their hematomalignancy: A randomized clinical trial.

BACKGROUND: No definitive protocol has been introduced for treatment or prevention of chemotherapy induced mucositis. The aim of this study was to assess the additive effect of Persica and chlorhexidine on chemotherapy induced mucositis of children with hematomalignancies. MATERIAL AND METHODS: This randomized clinical trial was performed on 44 children aged 6 to 12 years who were under a similar maintenance chemotherapy protocol for their hematomalignancies. The clinician instructed oral hygiene cares to the patients and their parents and the severity of the mucositis and oral health status of patients were evaluated according to Oral Assessment Guide index. Then, the patients were randomly assigned to one of two experimental groups and were instructed to rinse either with Persica oral drops or normal saline, twice a day for two weeks. Subsequently, the patients in both groups were educated to rinse with chlorhexidine for 30 seconds and avoid eating for an hour. Second and third oral examinations were performed on the 8th and 15th day using the same questionnaire. RESULTS: Comparing severity of mucositis and oral health status of patients did not show any significant difference between treatment groups in either of examination sessions (p>0.05). However, both treatment groups showed statistically significant oral health improvement, in terms of mucositis, plaque accumulation and gingival condition, in 14 days following mouthrinses administration (p<0.05). CONCLUSIONS: Both mouth-rinse combinations were effective on mucositis, plaque and gingival status of children receiving chemotherapy. However, Persica does not seem to pose additional effect on chlorhexidine in decreasing severity of chemotherapy induced mucositis. Key words:Mucositis, chemotherapy, children, chlorhexidine, Persica.

Molecular Targeting and Rational Chemotherapy in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a molecularly complex disease with multiple aberrant genetic pathways involved in its pathogenesis. Approximately one-third to one-half of patients with AML would relapse, and no standard therapy is established for relapsing and/or refractory AML (RR-AML) yet. It is unlikely that blockage of only one specific pathway will lead to prolonged remissions and cures in all fractions of the AML patients population. Nowadays, novel therapeutic agents with rational combination are being recognized which improve the cure rate for relapsed AML. These drugs and their metabolites impart unique properties in the interaction with each of the intracellular targets and metabolic enzymes whereby resulting in unique clinical activity. To date, most of the combinations have used a targeted agent combined with standard agents such as anthracyclines, cytarabine, or hypomethylating agents to improve the outcome. Rational combinations of DNA damage-inducing therapies with DNA methyltransferase and histone deacetylase inhibitors synergistically enhance the DNA damage, growth inhibition and apoptosis of myeloid cells. This review makes a thorough look at current antineoplastic agents for AML with emphasis on its genetics and molecular mechanisms of action and the role of combination regimens.

Genetic Characterization and Risk Stratification of Acute Myeloid Leukemia.

The most common acute leukemia in adults is acute myeloid leukemia (AML). The pathophysiology of the disease associates with cytogenetic abnormalities, gene mutations and aberrant gene expressions. At the molecular level, the disease manifests as changes in both epigenetic and genetic signatures. At the clinical level, two aspects of AML should be taken into account. First, the molecular changes occurring in the disease are important prognostic and predictive markers of AML. Second, use of novel therapies targeting these molecular changes. Currently, cytogenetic abnormalities and molecular alterations are the common biomarkers for the prognosis and choice of treatment for AML. Finding a panel of multiple biomarkers is a crucial diagnostic step for patient classification and serves as a prerequisite for individualized treatment strategies. Furthermore, the most important way of identifying relevant targets for new treatment approaches is defining specific patterns or a spectrum of driver gene mutations occurring in AML. Then, an algorithm can be established by the use of several biomarkers, to be used for personalized medicine. This review deals with molecular alterations, risk stratification, and relevant therapeutic decision-making in AML.

Ultrasensitive optical biosensor for detection of miRNA-155 using positively charged Au nanoparticles.

An ultrasensitive optical biosensor for microRNA-155 (miR-155) was developed to diagnose breast cancer at early stages. At first, the probe DNA covalently bind to the negatively charged gold nanoparticles (citrate-capped AuNPs). Then, the target miR-155 electrostatically adsorb onto the positively charged gold nanoparticles (polyethylenimine-capped AuNP) surface. Finally, by mixing citrate-capped AuNP/probe and polyethylenimine-capped AuNP/miR-155, hybridization occurs and the optical signal of the mixture give a measure to quantify the miR-155 content. The proposed biosensor is able to specify 3-base-pair mismatches and genomic DNA from target miR-155. The novelty of this biosensor is in its ability to trap the label-free target by its branched positively charged polyethylenimine. This method increases loading the target on the polyethylenimine-capped AuNPs' surface. So, proposed sensor enables miR-155 detection at very low concentrations with the detection limit of 100 aM and a wide linear range from 100 aM to 100 fM.

Myricetin protects hippocampal CA3 pyramidal neurons and improves learning and memory impairments in rats with Alzheimer's disease.

There is currently no treatment for effectively slowing the progression of Alzheimer's disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The present study investigated the effects of myricetin, a member of the flavonoids, on intracerebroventricular streptozotocin induced neuronal loss and memory impairment in rat models of Alzheimer's disease. Myricetin at 5 or 10 mg/kg was intraperitoneally injected into rats over 21 days. Control rats were treated with 10 mL/kg saline. Behavioral test (the shuttle box test) was performed on day 22 to examine learning and memory in rats. Immediately after that, hematoxylin-eosin staining was performed to observe the morphological change in hippocampal CA3 pyramidal neurons. Myricetin greatly increased the number of hippocampal CA3 pyramidal neurons and improved learning and memory impairments in rats with Alzheimer's disease. These findings suggest that myricetin is beneficial for treatment of Alzheimer's disease.

Antioxidant and cholinesterase inhibitory activity of a new peptide from Ziziphus jujuba fruits.

Antioxidant agents and cholinesterase inhibitors are the foremost drugs for the treatment of Alzheimer's disease (AD). In this study, a new peptide from Ziziphus jujuba fruits was investigated for its inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes as well as antioxidant activity. This peptide was introduced as a new peptide and named Snakin-Z. The Snakin-Z displayed considerable cholinesterase inhibition against AChE and BChE. The half maximal inhibitory concentration (IC50) values of Snakin-Z against AChE and BChE are 0.58 ± 0.08 and 0.72 ± 0.085 mg/mL, respectively. This peptide has 80% enzyme inhibitory activity on AChE and BChE at 1.5 mg/mL. The Snakin-Z also had the high antioxidant activity (IC50 = 0.75 ± 0.09 mg/mL). Thus, it is suggested that Snakin-Z may be beneficial in the treatment of AD. However, more detailed researches are still required as in vivo testing its anticholinesterase and antioxidant activities.