Isozyme-selective, Lung-selective Mechanism-based Inhibitors Of Cytochrome P-450 And Determination Of P450 Isozyme Specificity For Arachidonic Acid Metabolism

1-Aminobenzotriazole (ABT) and its N-benzyl (BBT) and N-{dollar}\alpha{dollar}-methylbenzyl ({dollar}\alpha{dollar}MB) derivatives were compared as isozyme-selective, lung-selective (vs liver) mechanism-based inhibitors of P450 in guinea pigs 4 hr following i.v. administration. Monooxygenase activities selective for guinea pig orthologues of rabbit P450 1A1, 2B4 and 4B1 (1A1, 2Bx and 4Bx, respectively) were determined in pulmonary and hepatic microsomes. BBT and {dollar}\alpha{dollar}MB inactivated pulmonary P450 in an isozyme-selective manner. In non-induced and phenobarbital-induced animals the order of inactivation was 2Bx {dollar}\u3e{dollar} 1A1 {dollar}\u3e\u3e\u3e\u3e{dollar} 4Bx whereas in {dollar}\beta{dollar}-naphthoflavone-induced animals {dollar}\alpha{dollar}MB specifically inhibited 2Bx. BBT and {dollar}\alpha{dollar}MB were also highly selective for the inactivation of pulmonary vs hepatic P450. In non-induced and induced animals at least one of the doses examined caused marked inactivation of pulmonary 2Bx ({dollar}\u3e{dollar}80% with {dollar}\alpha{dollar}MB and 50-70% with BBT) without inhibiting any of the hepatic monooxygenase activities. In contrast, ABT displayed little isozyme-selectivity and little tissue-selectivity.;Guinea pig lung microsomes were found to convert arachidonic acid to two classes of P450-dependent metabolites, 16- through 20-hydroxyeicosatetraenoic acids ((16-20)-OH-AA) and epoxyeicosatrienoic acids (EETs). (16-20)-OH-AA formation was increased by {dollar}\beta{dollar}-naphthoflavone treatment. P450 2B selective inhibitors (metyrapone, SKF-525A and {dollar}\alpha{dollar}MB) as well as antibodies to rabbit P450 2B4 inhibited EETs formation by {dollar}\u3e{dollar}85%-{dollar}\u3e{dollar}95% with little effect on (16-20)-OH-AA formation. Neither a P450 1A selective inhibitor ({dollar}\alpha{dollar}-naphthoflavone) nor antibodies to rabbit P450 4B1 inhibited the formation of either class o{dollar}\sp-{dollar} metabolites. These data demonstrate that P450 2Bx is solely responsible for the metabolism of arachidonic acid to EETs in guinea pig lung and that a form of P450 other than 2Bx, 4Bx or 1A1, which is inducible by {dollar}\beta{dollar}-naphthoflavone, forms (16-20)-OH-AA.;Guinea pig kidney microsomoes also formed (16-20)-OH-AA and EETs. The formation of these metabolites was not affected by {dollar}\beta{dollar}-naphthoflavone induction or P450 1A1 inhibitors demonstrating that P450 1A1 also does not contribute to arachidonic acid metabolism in guinea pig kidney.;In summary, BBT and {dollar}\alpha{dollar}MB, at appropriate doses, are isozyme-selective/specific (P450 2Bx), lung-specific inhibitors of P450 in guinea pig in vivo. In guinea pig lung, P450 2Bx is responsible for the metabolism of arachidonic acid to EETs. Guinea pig P450 4Bx and 1A1 do not metabolize arachidonic acid

Experimental Assessment of the Current Load Rating Procedures for a Corroded Steel Ridge Girder in Massachusetts

The work conducted for this project involves an experimental assessment of the Massachusetts Department of Transportation’s (MassDOT) existing procedure for determining the resistance of a corroded steel girder end when load rating a bridge. Three steel girders with significant corrosion developed over a 79-year service life were obtained from a recently rehabilitated bridge and loaded to determine the girders corroded resistance. A testing rig was designed in the UMass Amherst Brack Structural Testing Laboratory to both apply a shear dominated load to the corroded girder and withstand the developed lateral loads throughout the analysis. Reaction force data obtained from the load testing was compared against the corroded web factored resistance determined from the MassDOT LRFD Bridge Design Manual. Resistances were under predicted by 75% for specimen 1, 37% for specimen 2 and the manual predicted no resistance for specimen 3. Lastly influences for the discrepancies between manual resistance and experimental resistance are determined

DNA Unicorn: An N-of-1 Community Advocacy Resource

With the wider use of genetic testing, an increasing number of people are receiving molecular diagnoses of ultra-rare or N-of-1 diseases. The medical and psychosocial challenges of these individuals are compounded by a lack of support and advice from disease-specific communities. A website ( www.dnaunicorn.org) was developed to help N-of-1 families connect with caregivers, researchers, and patients with the same or related medical conditions. The site provides directions and links to resources to facilitate data-sharing through access to databases, and aids in the construction of social media campaigns to connect genotypically- or phenotypically-related patients and families to each other. Furthermore, the website provides step-by-step instructions and templates for users to optimize their use of Twitter, Facebook, GenomeConnect, MyGene2 and other potential avenues to find and build a community. Fourteen genetic counselors provided feedback by answering seven questions on the usefulness of an early version of the web-based tool kit. Free text responses were also elicited. Five themes emerged in qualitative analysis of their responses: aesthetics, language, resource choice, how-to guide utility, and overall clinical utility. Aesthetics was mentioned most frequently, with eight genetic counselors commenting on font size and text placement. Responses to the website were overwhelmingly positive; 100% of participants agreed that it would be useful in clinical practice and would refer patients to the website. Counselors also described a need for more resources for families with N-of-1 or ultra-rare molecular diagnoses, which our site attempts to address

Comprehensive EST analysis of Atlantic halibut (Hippoglossus hippoglossus), a commercially relevant aquaculture species

<p>Abstract</p> <p>Background</p> <p>An essential first step in the genomic characterisation of a new species, in this case Atlantic halibut (<it>Hippoglossus hippoglossus</it>), is the generation of EST information. This forms the basis for subsequent microarray design, SNP detection and the placement of novel markers on genetic linkage maps.</p> <p>Results</p> <p>Normalised directional cDNA libraries were constructed from five different larval stages (hatching, mouth-opening, midway to metamorphosis, premetamorphosis, and post-metamorphosis) and eight different adult tissues (testis, ovary, liver, head kidney, spleen, skin, gill, and intestine). Recombination efficiency of the libraries ranged from 91–98% and insert size averaged 1.4 kb. Approximately 1000 clones were sequenced from the 5'-end of each library and after trimming, 12675 good sequences were obtained. Redundancy within each library was very low and assembly of the entire EST collection into contigs resulted in 7738 unique sequences of which 6722 (87%) had matches in Genbank. Removal of ESTs and contigs that originated from bacteria or food organisms resulted in a total of 7710 unique halibut sequences.</p> <p>Conclusion</p> <p>A Unigene collection of 7710 functionally annotated ESTs has been assembled from Atlantic halibut. These have been incorporated into a publicly available, searchable database and form the basis for an oligonucleotide microarray that can be used as a tool to study gene expression in this economically important aquacultured fish.</p

Key challenges in simulated patient programs: An international comparative case study

<p>Abstract</p> <p>Background</p> <p>The literature on simulated or standardized patient (SP) methodology is expanding. However, at the level of the program, there are several gaps in the literature. We seek to fill this gap through documenting experiences from four programs in Australia, Canada, Switzerland and the United Kingdom. We focused on challenges in SP methodology, faculty, organisational structure and quality assurance.</p> <p>Methods</p> <p>We used a multiple case study method with cross-case synthesis. Over eighteen months during a series of informal and formal interactions (focused meetings and conference presentations) we documented key characteristics of programs and drew on secondary document sources.</p> <p>Results</p> <p>Although programs shared challenges in SP methodology they also experienced differences. Key challenges common to programs included systematic quality assurance and the opportunity for research. There were differences in the terminology used to describe SPs, in their recruitment and training. Other differences reflected local conditions and demands in organisational structure, funding relationships with the host institution and national trends, especially in assessments.</p> <p>Conclusion</p> <p>This international case study reveals similarities and differences in SP methodology. Programs were highly contextualised and have emerged in response to local, institutional, profession/discipline and national conditions. Broader trends in healthcare education have also influenced development. Each of the programs experienced challenges in the same themes but the nature of the challenges often varied widely.</p

Study of multiphase flow useful to understanding scaleup of coal-liquefaction reactors. Technical progress report, September 1, 1981-November 30, 1981

The major portion of the time spent on this project for this quarter involved specifying and ordering the equipment required to construct the 13 inch inside diameter column. The superstructure has been constructed in the laboratory and all major equipment has been ordered. In addition a series of dynamic gas disengagement experiments have been performed using the six inch inside diameter column. The major objective of these experiments was to determine whether the distribution has any effect on the bubble rise velocities. No major difference was found when the data for a porous plate and a sieve plate was compared

Niche partitioning in sympatric Greenland cod (Gadus ogac) and Atlantic cod (Gadus morhua) in coastal Newfoundland

Niche partitioning, the process by which evolutionary pressures divert competing species into different patterns of resource use, is often used to explain the coexistence of closely related species. In this thesis, I test the theory that niche partitioning facilitates the coexistence of two sympatric gadid species (Atlantic cod and Greenland cod) in a coastal region of Newfoundland using a multi-method approach. Dietary and isotopic analyses were used to examine the degree of trophic niche overlap between species. Results revealed a general partitioning of food resources; G. morhua consumed more pelagic prey and showed a more pelagic (more negative) δ¹³C signature while G. ogac consumed more benthic prey and had a more benthic (more positive) δ¹³C signature. It was concluded that interspecific competition for prey resources and dietary overlap is low and that trophic niche partitioning is likely a key mechanism enabling coexistence. Acoustic-radio telemetry was used to examine the spatial and temporal movement patterns of juveniles during summer. G. morhua were wider ranging, moved at faster rates and were active throughout the diel cycle compared to G. ogac of the same size suggesting spatial and temporal niche partitioning occurs between species during the summer season. Fine-scale habitat use and vertical distributions were investigated using radio-acoustic positioning and habitat mapping. Both species preferred coarse substrates with moderate or dense vegetation, areas of low bathymetric relief and shallow (<10 m) water. G. ogac remained closer to the seafloor while G. morhua was generally distributed more pelagically and showed greater variation in vertical positioning. Results indicated high overlap in microhabitat use but differential use of vertical habitat which may reduce competitive interference between species. Size-at-age and maturity data were used to compare growth rates and maturity patterns between species. Age and size at maturity were lower for G. ogac than for G. morhua despite similar growth rates. Length-weight relationships suggested slightly positive and negative allometric growth, for G. ogac and G. morhua respectively. It was concluded that differences in maturity patterns may promote coexistence by decreasing resource competition between species. In summary, the findings from this thesis suggest that niche partitioning occurs along several niche dimensions which facilitate coexistence between ecologically similar Atlantic and Greenland cod in coastal waters of Newfoundland

Study of multiphase flow useful to understanding scaleup of coal-liquefaction reactors.

Report on the study of multiphase flow to understand further scaleup of coal liquefaction reactors, is given. Gas holdup measurements for air and water were made using the 13 inch acrylic column to test the equipment. The preliminary results indicate all the equipment and the experimental techniques work satisfactorily. Preliminary analyis indicates the use of porous plates as a gas distributor in the 6 inch column yield gas holdup values close to 0.25 at the bubble and bubble slug transition. A number of porous plates were used of different material, pore size and thickness. (from author\u27s abstract) (Microfiche