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Surface Tissues (surface + tissue)

Distribution by Scientific Domains

Life Sciences	75%

Selected Abstracts

Development and demonstration of RNA isolation and RT,PCR procedures to detect Escherichia coli O157:H7 gene expression on beef carcass surfaces

LETTERS IN APPLIED MICROBIOLOGY, Issue 4 2000
E.D. Berry
Preventing the development of pathogen resistance to processing and preservation techniques will require an understanding of the genetic mechanisms that pathogens use in situ to adapt and develop tolerance to stresses they encounter in the food environment. RNA isolation and reverse-transcription (RT),PCR protocols were developed as tools to detect gene expression in bacteria on beef carcass surfaces. The utility of these procedures was demonstrated by detecting the expression of a selectively-inducible green fluorescent protein (GFP) gene in a plasmid-transformed strain of Escherichia coli O157:H7 inoculated onto beef carcass surface tissue. These procedures should serve as useful tools for studying the genetic responses of bacteria when exposed to antimicrobial interventions applied to food animal carcasses. [source]

Molecular systematics of the speciose Indo-Pacific soft coral genus, Sinularia (Anthozoa: Octocorallia)

INVERTEBRATE BIOLOGY, Issue 4 2009
Catherine S. McFadden
Abstract. The speciose tropical soft coral genus Sinularia traditionally has been divided into five intrageneric taxonomic groups based on variation in a single morphological character: the shape of the club sclerites (calcite skeletal elements) embedded in the surface tissues of the colony. To test the phylogenetic utility of this system of classification, we used a 735-bp fragment of the octocoral-specific mitochondrial msh1 gene to construct a molecular phylogeny that included 80 of the ,150 recognized morphospecies of Sinularia. The msh1 phylogeny recovered five well-supported clades, but they were not congruent with the traditional intrageneric taxonomic groups. Mapping of characters onto the tree suggested that the five major clades plus several additional sub-clades of Sinularia can be distinguished based on a suite of four morphological characters; these include the presence of sclerites in the tentacle, collaret, and point regions of the polyps, in addition to the shape of the club sclerites in the surface tissues. The overall growth form of the colony also distinguishes some clades. Polyp sclerites have for the most part been overlooked taxonomically in Sinularia, and as a result information on these characters is lacking or is incorrect in many species descriptions. As has been the case in other recent studies of lower metazoan groups, construction of a molecular phylogeny has led us to recognize the phylogenetic and taxonomic importance of previously overlooked morphological characters. A revised taxonomic key that includes these characters is already improving our ability to discriminate species boundaries, and facilitating description of new Sinularia species. [source]

Non-invasive quantification of endogenous root auxin transport using an integrated flux microsensor technique

THE PLANT JOURNAL, Issue 6 2010
Eric S. McLamore
Summary Indole-3-acetic acid (IAA) is a primary phytohormone that regulates multiple aspects of plant development. Because polar transport of IAA is an essential determinant of organogenesis and dynamic tropic growth, methods to monitor IAA movement in vivo are in demand. A self-referencing electrochemical microsensor was optimized to non-invasively measure endogenous IAA flux near the surface of Zea mays roots without the addition of exogenous IAA. Enhanced sensor surface modification, decoupling of acquired signals, and integrated flux analyses were combined to provide direct, real time quantification of endogenous IAA movement in B73 maize inbred and brachytic2 (br2) auxin transport mutant roots. BR2 is localized in epidermal and hypodermal tissues at the root apex. br2 roots exhibit reduced shootward IAA transport at the root apex in radiotracer experiments and reduced gravitropic growth. IAA flux data indicates that maximal transport occurs in the distal elongation zone of maize roots, and net transport in/out of br2 roots was decreased compared to B73. Integration of short term real time flux data in this zone revealed oscillatory patterns, with B73 exhibiting shorter oscillatory periods and greater amplitude than br2. IAA efflux and influx were inhibited using 1- N -naphthylphthalamic acid (NPA), and 2-naphthoxyacetic acid (NOA), respectively. A simple harmonic oscillation model of these data produced a correlation between modeled and measured values of 0.70 for B73 and 0.69 for br2. These results indicate that this technique is useful for real-time IAA transport monitoring in surface tissues and that this approach can be performed simultaneously with current live imaging techniques. [source]

Bimatoprost: Mechanism of Ocular Surface Hyperemia Associated with Topical Therapy

CARDIOVASCULAR THERAPEUTICS, Issue 3 2005
June Chen
ABSTRACT Bimatoprost is a safe and well-tolerated intraocular pressure (IOP) lowering drug that was approved in the United States in 2001 for the treatment of glaucoma and ocular hypertension. It is highly efficacious and produces greater mean reductions in IOP than other currently available antiglaucoma drugs. Conjunctival hyperemia is a common side effect of bimatoprost, but the hyperemia is typically mild and transient. No association has been found between signs of inflammation and the presence of hyperemia in bimatoprost-treated patients. Preclinical studies have elucidated the pharmacological mechanism of bimatoprost-related hyperemia and have examined the possible involvement of inflammation. Bimatoprost, as well as the free acid of latanoprost, elicited endothelium-de-pendent vasorelaxation in the rabbit jugular vein preparation, a quantitative in vitro model for ocular surface hyperemia (OSH). The vasorelaxant responses to either bimatoprost or latanoprost free acid were significantly inhibited by L-NAME, a nitric oxide synthase inhibitor. Similarly, the in vivo OSH responses to topically applied bimatoprost or latanoprost in dog eyes were significantly inhibited by L-NAME. As predicted, prostaglandin E2 (PGE2)-induced conjunctival hyperemia was not inhibited by L-NAME, since PGE2 has a direct relaxant effect on the vascular smooth muscle. In-life observations and histopatho-logical assessment of ocular surface tissues following bimatoprost treatment were performed for multiple-dose one month, 6 month, or 12 month safety studies in rabbits, dogs, and non-human primates. Results of these studies showed no evidence of bimatoprost-re-lated inflammation in the ocular surface tissues. In summary, OSH related to bimatoprost treatment in laboratory animals occurs by endothelial-derived nitric oxide-mediated vasodilatation and is not associated with inflammation. These studies suggest that conjunctival hyperemia, a side effect of bimatoprost treatment, results from non-inflammatory, pharmacologically based vasodilatation. [source]