During neuronal development, neurons undergo significant microtubule reorganization to shape axons and dendrites, establishing the framework for efficient wiring of the nervous system. Previous studies from our laboratory demonstrated the key role of kinesin-1 in driving microtubule-microtubule sliding, which provides the mechanical forces necessary for early axon outgrowth and regeneration in In this study, we reveal the critical role of kinesin-5, a mitotic motor, in modulating the development of postmitotic neurons. Kinesin-5, a conserved homotetrameric motor, typically functions in mitosis by sliding antiparallel microtubules apart in the spindle.
View Article and Find Full Text PDFBackground: Electrical neuromodulation via implanted electrodes is used in treating numerous neurological disorders, yet our knowledge of how different brain regions respond to varying stimulation parameters is sparse.
Objective/hypothesis: We hypothesized that the neural response to electrical stimulation is both region-specific and non-linearly related to amplitude and frequency.
Methods: We examined evoked neural responses following 400 ms trains of 10-400 Hz electrical stimulation ranging from 0.
Parasitic nematodes pose a serious threat to agriculture, livestock, and human health. Increasing resistance to antiparasitic agents underscores the need to replenish our anthelmintic arsenal. The nonpathogenic Caenorhabditis elegans, which serves as an effective model of parasitic helminths, has been used to search for new anthelmintic leads.
View Article and Find Full Text PDFCytochrome P450 2B6 (CYP2B6), mainly expressed in the liver and brain, is important for processing a number of widely used drugs. Variations in CYP2B6 expression are associated with decreased drug efficacy or adverse effects in some patients. Although CYP2B6 genetic variants are associated with its differential expression, epigenetic mechanisms affecting CYP2B6 gene regulation have not been established.
View Article and Find Full Text PDFCytochrome P450 2C19 (CYP2C19) is involved in the metabolism of many drugs. Extensive studies have demonstrated that genetic variants and endogenous and environmental factors play important roles in the expression of CYP2C19. However, the role of microRNAs (miRNAs) in controlling CYP2C19 expression has not been investigated completely.
View Article and Find Full Text PDFJ Environ Sci Health C Environ Carcinog Ecotoxicol Rev
January 2015
The aim of this review is to comprehensively summarize the recent achievements in the field of toxicogenomics and cancer research regarding genetic-environmental interactions in carcinogenesis and detection of genetic aberrations in cancer genomes by next-generation sequencing technology. Cancer is primarily a genetic disease in which genetic factors and environmental stimuli interact to cause genetic and epigenetic aberrations in human cells. Mutations in the germline act as either high-penetrance alleles that strongly increase the risk of cancer development, or as low-penetrance alleles that mildly change an individual's susceptibility to cancer.
View Article and Find Full Text PDFPreviously, we reported five common single nucleotide polymorphisms (SNPs), -624G>C, -396G>A, -358A>C, -341C>G, and -294T>C, and six common haplotypes (CGACT, GAACT, GGAGC, GGACC, CAACT, and GAACC) in the 5'-flanking region of the SULT1A1 gene that were associated with altered enzymatic activity. In the present study, we performed in vitro assays to determine the functional impact of these genetic variations on the promoter activity. Dual luciferase reporter assays revealed that these SNPs are located in a negative regulatory fragment of the SULT1A1 gene.
View Article and Find Full Text PDFHumans at all ages are continually exposed to triclosan (TCS), a widely used antimicrobial agent that can be found in many daily hygiene products, such as toothpastes and shampoos; however, the toxicological and biological effects of TCS in the human body after long-term and low-concentration exposure are far from being well understood. In the current study, we investigated the effects of TCS on the differentiation of human mesenchymal stem cells (hMSCs) by measuring the cytotoxicity, morphological changes, lipid accumulation, and the expression of adipocyte differentiation biomarkers during 21-day adipogenesis. Significant cytotoxicity was observed in un-induced hMSCs treated with high-concentration TCS (≥ 5.
View Article and Find Full Text PDFIn addition to primary human hepatocytes, hepatoma cell lines, and transfected nonhepatoma, hepatic cell lines have been used for pharmacological and toxicological studies. However, a systematic evaluation and a general report of the gene expression spectra of drug-metabolizing enzymes and transporters (DMETs) in these in vitro systems are not currently available. To fill this information gap and to provide references for future studies, we systematically characterized the basal gene expression profiles of 251 drug-metabolizing enzymes in untreated primary human hepatocytes from six donors, four commonly used hepatoma cell lines (HepG2, Huh7, SK-Hep-1, and Hep3B), and one transfected human liver epithelial cell line.
View Article and Find Full Text PDFBackground: In June 2006, the Advisory Committee on Immunization Practices (ACIP) expanded its June 2005 recommendation for a second dose of varicella vaccine during outbreaks to a recommendation for routine school entry second dose varicella vaccination. In October 2006, the Arkansas Department of Health was notified of a varicella outbreak among students where some received a second dose during an outbreak-related vaccination campaign in February 2006.
Methods: The outbreak was investigated using a school-wide parental survey with a follow-up survey of identified case patients.
Purpose: The oncolytic effects of a systemically delivered, replicating, double-deleted vaccinia virus has been previously shown for the treatment of many cancers, including colon, ovarian, and others. The purpose of this study was to investigate the oncolytic potential of double-deleted vaccinia virus alone or in combination with rapamycin or cyclophosphamide to treat malignant gliomas in vitro and in vivo.
Experimental Design: Rat (RG2, F98, C6) and human (A172, U87MG, U118) glioma cell lines were cultured in vitro and treated with live or UV-inactivated vaccinia virus.
Skin, particularly the uppermost layer--the stratum corneum--presents a formidable, largely impassable barrier to the entry of most compounds. Recently, a novel thermolabile, low-residue foam vehicle, VersaFoam (Connetics Corp, Palo Alto, Calif), has emerged that offers a number of clinical and cosmetic advantages for the delivery of therapeutic agents through the skin. Two corticosteroids--mid-potency betamethasone valerate and ultra-high-potency clobetasol propionate--are now available in this formulation, and other products are in development to deliver clindamycin and ketoconazole in the foam vehicle.
View Article and Find Full Text PDFWhile important in carcinogenesis, the role of Ras in normal self-renewing tissues such as epidermis is unclear. To address this, we altered Ras function in undifferentiated and differentiating epidermal layers. Ras blockade within undifferentiated basal epidermal cells leads to decreased integrin expression, diminished growth capacity and induction of differentiation.
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