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Dennis Et Al. (Denni + et_al)

Distribution by Scientific Domains
Life Sciences60%

Selected Abstracts

Immunohistochemistry of the canine vomeronasal organ

JOURNAL OF ANATOMY, Issue 3 2003
Article first published online: 2 SEP 200
The publisher regrets that in Volume 202, Issue 6 of the Journal of Anatomy, the article Immunohistochemistry of the canine vomeronasal organ by J. C. Dennis et al. was inadvertently printed in black and white. It appears in this issue of the Journal of Anatomy (pp 329338) as it was originally intended. [source]

Oncogene expression profiles in K6/ODC mouse skin and papillomas following a chronic exposure to monomethylarsonous acid,

JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 6 2009
Don A. Delker
Abstract We have previously observed that a chronic drinking water exposure to monomethylarsonous acid [MMA(III)], a cellular metabolite of inorganic arsenic, increases tumor frequency in the skin of keratin VI/ornithine decarboxylase (K6/ODC) transgenic mice. To characterize gene expression profiles predictive of MMA(III) exposure and mode of action of carcinogenesis, skin and papilloma RNA was isolated from K6/ODC mice administered 0, 10, 50, and 100 ppm MMA(III) in their drinking water for 26 weeks. Following RNA processing, the resulting cRNA samples were hybridized to Affymetrix Mouse Genome 430A 2.0 GeneChips®. Micoarray data were normalized using MAS 5.0 software, and statistically significant genes were determined using a regularized t -test. Significant changes in bZIP transcription factors, MAP kinase signaling, chromatin remodeling, and lipid metabolism gene transcripts were observed following MMA(III) exposure as determined using the Database for Annotation, Visualization and Integrated Discovery 2.1 (DAVID) (Dennis et al., Genome Biol 2003;4(5):P3). MMA(III) also caused dose-dependent changes in multiple Rho guanine nucleotide triphosphatase (GTPase) and cell cycle related genes as determined by linear regression analyses. Observed increases in transcript abundance of Fosl1, Myc, and Rac1 oncogenes in mouse skin support previous reports on the inducibility of these oncogenes in response to arsenic and support the relevance of these genomic changes in skin tumor induction in the K6/ODC mouse model. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:406,418, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20304 [source]

Absence of Iatrogenic or Contagion Effects in Adolescent Group Therapy: Findings from the Cannabis Youth Treatment (CYT) Study

THE AMERICAN JOURNAL ON ADDICTIONS, Issue 2006
Joseph A. Burleson PhD
Though widely used and presumed effective in practice, some scholars (Dishion et al., 1999) have raised the concern that group therapy for adolescents with substance use disorder and a range of deviancy has the potential for causing iatrogenic effects (e.g., increased substance use, behavior and legal problems) for those with low deviancy. Using data from 400 youth in the largest adolescent treatment experiment conducted to date (Dennis et al., 2004), this study shows that group composition in terms of conduct disorder symptoms is not associated with worse substance use, psychological, environmental or legal treatment outcomes. The results actually indicated that there was a slight advantage for youth with high conduct disorder to be included in the groups with less symptoms. The results appear consistent with recent meta-analyses of delinquency studies (Lipsey, 2006) which have found no evidence of iatrogenic effects. These results support the common clinical belief that group therapy for youths with substance use disorders is a safe and effective treatment modality. [source]

Helicase homologues maintain cytosine methylation in plants and mammals

BIOESSAYS, Issue 4 2002
Déborah Bourc'his
The Arabidopsis DDM1 gene is required for the maintenance of genomic methylation patterns but is a helicase homolog of the SWI2/SNF2 family rather than a DNA methyltransferase.(1) Dennis et al.(2) have shown that disruption of the mouse Lsh gene, the mammalian gene most closely related to DDM1, causes demethylation of the mouse genome. This result suggests that the mechanisms that maintain methylation patterns in the genomes of mammals and flowering plants are more conserved than previously suspected. BioEssays 24:297,299, 2002. ©2002 Wiley Periodicals, Inc. [source]

Enhanced IFN, production in adenosine-treated CHOCells: A mechanistic study

BIOTECHNOLOGY PROGRESS, Issue 3 2009
William P. K. Chong
Abstract Adenosine causes growth arrest in recombinant mammalian cell cultures, which results in enhanced productivity of the recombinant protein. Adenosine is also known to increase intracellular ATP level when added to mammalian cells. As a cell's energy level affects its protein expression capacity, we investigated the factors that contribute to the increase in recombinant protein productivity. Chinese hamster ovary (CHO) cells expressing human interferon-gamma (IFN,) were treated with 1 mM adenosine on Day 2 of culture. The growth arrest resulted in 60% reduction in integral viable cell density when compared with control. However, IFN, titer improved 1.4-fold alongside a 2.5-fold increase in average specific productivity. The adenosine-treated cells also experienced a two-fold increase in ATP level that sustained for 3 days. Western blot studies revealed a relatively short-lived but strong activation of the energy sensor AMP-activated protein kinase (AMPK) in adenosine-treated cells. Activation of AMPK was probably due to adenosine being temporarily converted to AMP. Activated AMPK should have down-regulated protein translation by preventing mammalian target of rapamycin (mTOR) from phosphorylating and inactivating 4E-binding protein 1 (4E-BP1), a key repressor of protein translation initiation. However, Western blots showed increased phosphorylation of 4E-BP1 on Day 2 that lasted 3 days. This implied that a high concentration of ATP could keep 4E-BP1 inhibited, probably by directly modulating mTOR. This corroborated with an earlier in vitro observation (Dennis et al., Science. 2001;294:1102-1105). Inhibition of translation initiation repression is thus likely to contribute in part to the improvement in IFN,-specific productivity and titer. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]