933 research outputs found
Characterization of allantoinase from Eschericia coli
No full textThe purpose of this research was to characterize the Escherichia coli, E. coli,
allantoinase enzyme. Allantoinase catalyses the conversion allantoin to allantoate via
the hydrolysis of a cyclic amide bond and is coded for by the allB gene. The enzyme is
a member of the amidohydrolase superfamily. Amidohydrolase superfamily enzymes
have a common (αβ)8-barrel structure but catalyze the hydrolysis of many different
substrates by a common mechanism. The structural characteristics and roles of divalent
cations of enzymes in this superfamily will be discussed and related to previous work
conducted on allantoinases. In this work, the metal dependence of allantoinase was
initially studied by Mn, Co, Zn, Cd, and Ni-supplemented assays of enzyme of very low
metal content. By changing the growth conditions under which the allB was
overexpressed in E. coli, and the addition of Zn, Co or Mn to the culture, enzyme with
bound Zn (ZnALN), Co (CoALN) or Mn (MnALN) was produced. The pH dependence
of log (kcat/KM) for allantoinase in the presence of MnCl2, ZnALN and CoALN followed
a bell-shaped curve, indicating that one ionizable group needed to be deprotonated and
the deprotonation of a second group caused a decrease in catalytic activity. The pK1 for
ionization at low pH was dependent upon which divalent cation was present and is concluded to be that of the deprotonation of water. A structural model of allantoinase
with bound allantoin was constructed and used to determine which amino acid residues
may be involved in catalysis. Allantoinase mutants R67K, C152A, C152S, C287A,
C287S, S317A, D315N and W332F were purified. The kinetic parameters kcat, KM and
kcat/KM of wild type and mutant allantoinases were compared. The possible roles of
these amino acid residues in catalysis and substrate binding, and the results of the pH
rate profiles are discussed. A catalytic mechanism for allantoinase is proposed
The level of education and loss of earning capacity for Wisconsin worker's compensation claimants
No full textPlan BLoss of earning capacity is only one brief component of Worker’s Compensation. There are many factors involved in determining a person’s level of loss of earnings. Level of education is a factor that will affect a person’s lost earning capacity. In this study, the educational level of the individual will be correlated with their estimated loss of earning capacity
Gender-associated gene expression in two related strains of Schistosoma japonicum
No full textHost inflammatory responses directed against eggs laid by sexually-mature Schistosoma japonicum female worms instigate lesion formation and associated clinical pathologies during infection. To identify parasite gene transcripts that associate with egg production and to characterise sexually-mature adult gene expression profiles of two related Chinese strains, S. japonicum cDNA microarrays were fabricated using 457 ESTs originating from three parasite developmental stages. Twenty-two female-associated and 8 male-associated gene transcripts were identified in the adult Anhui strain whereas 21 female-associated and 7 male-associated gene transcripts were revealed in the adult Zhejiang strain. RT-PCR analysis, in situ enzyme localisation studies and enzymatic assays confirmed the cDNA microarray results, and importantly, provided information previously unappreciated in schistosome conjugal biology. Specifically, our novel findings include the female-specific expression of genes putatively involved in haemoglobin digestion and eggshell formation including extracellular superoxide dismutase, two histidine-rich proteins, a large blood-brain barrier amino acid transporter and two tyrosinase orthologues. In contrast, transcripts involved in mechanical support (actin), cytoskeletal infrastructure (e.g. dynein light chain 3 and myosin regulatory light chain) and tegumental biology (e.g. TM4SF and Sj25) were more highly represented in adult male schistosomes. Together these data establish a transcriptional basis for adult schistosome labour division and expands the list of novel S. japonicum gender-associated gene transcripts that may be considered targets for improved intervention strategies.</p
Efficacy of Laser Resurfacing and Facial Plastic Surgery Using Age, Glogau, and Fitzpatrick Rating
No full textBackground:. To assess clinical outcomes based on established rating scales in patients who underwent treatment for rhytids using laser resurfacing with and without facial plastic surgery.
Methods:. Retrospective case review of 48 patients treated by the senior author (J.E.B) between 2009 and 2016. Three reviewers assigned ratings to a total of 48 patients using estimated age and Fitzpatrick, Modified Fitzpatrick, and Glogau scales. Reviewers were blinded to patient demographics and before and after photographs. Patients elected to receive laser-only treatment or combination laser plus facial plastic surgery. Participants included forty-eight patients were selected on the basis that they had either laser treatment alone or laser plus facial plastic surgery and pre- and postoperative photographs.
Results:. Patients with higher Fitzpatrick scores had a greater reduction in Glogau score (ß = 1.66; SE = 0.59; P < 0.01). With respect to modified Fitzpatrick scores after surgery, patients with higher Glogau scores of 3 or 4 before surgery (P < 0.01) had higher scores after surgery ((ß = 0.07; SE = 0.02; P < 0.01). For estimated age, the average change was -1.7 years after laser resurfacing (P = 0.038; 95% CI, 2.96–3.06 years) and -2.07 years when combined with surgery (P = 0.01; 95% CI, 2.89–3.19 years).
Conclusions:. Patients with Fitzpatrick scores of 3, 4, 5, younger patients, and those with less rhytids before surgery tended to have lower Glogau scores after surgery. These findings provide insight on an approach to treating ethnic skin and aging face concerns
Use of genomic DNA as an indirect reference for identifying gender-associated transcripts in morphologically identical, but chromosomally distinct, Schistosoma mansoni cercariae.
No full textThe use of DNA microarray technology to study global Schistosoma gene expression has led to the rapid identification of novel biological processes, pathways or associations. Implementation of standardized DNA microarray protocols across laboratories would assist maximal interpretation of generated datasets and extend productive application of this technology.Utilizing a new Schistosoma mansoni oligonucleotide DNA microarray composed of 37,632 elements, we show that schistosome genomic DNA (gDNA) hybridizes with less variation compared to complex mixed pools of S. mansoni cDNA material (R = 0.993 for gDNA compared to R = 0.956 for cDNA during 'self versus self' hybridizations). Furthermore, these effects are species-specific, with S. japonicum or Mus musculus gDNA failing to bind significantly to S. mansoni oligonucleotide DNA microarrays (e.g R = 0.350 when S. mansoni gDNA is co-hybridized with S. japonicum gDNA). Increased median fluorescent intensities (209.9) were also observed for DNA microarray elements hybridized with S. mansoni gDNA compared to complex mixed pools of S. mansoni cDNA (112.2). Exploiting these valuable characteristics, S. mansoni gDNA was used in two-channel DNA microarray hybridization experiments as a common reference for indirect identification of gender-associated transcripts in cercariae, a schistosome life-stage in which there is no overt sexual dimorphism. This led to the identification of 2,648 gender-associated transcripts. When compared to the 780 gender-associated transcripts identified by hybridization experiments utilizing a two-channel direct method (co-hybridization of male and female cercariae cDNA), indirect methods using gDNA were far superior in identifying greater quantities of differentially expressed transcripts. Interestingly, both methods identified a concordant subset of 188 male-associated and 156 female-associated cercarial transcripts, respectively. Gene ontology classification of these differentially expressed transcripts revealed a greater diversity of categories in male cercariae. Quantitative real-time PCR analysis confirmed the DNA microarray results and supported the reliability of this platform for identifying gender-associated transcripts.Schistosome gDNA displays characteristics highly suitable for the comparison of two-channel DNA microarray results obtained from experiments conducted independently across laboratories. The schistosome transcripts identified here demonstrate, for the first time, that gender-associated patterns of expression are already well established in the morphologically identical, but chromosomally distinct, cercariae stage
Feminist bioethics and indigenous research reform in Australia : is an alliance across gender, racial, and cultural borders a useful strategy for promoting change?
No full textJennifer Baker, Terry Dunbar and Margaret Scrimgeourhttp://trove.nla.gov.au/work/2790549
Application of kinetic isotope effects and theoretical calculations to interesting reaction mechanisms
No full textA variety of biological and organic reaction mechanisms are studied using
powerful tools from experimental and theoretical chemistry. These tools include the
precise measurement of kinetic isotope effects (KIEs) and the use of theoretical
calculations to predict KIEs as well as determine factors that contribute to reaction
acceleration and selectivity.
Theoretical analysis of the Swain-Schaad relationship involves the prediction of
a large number of isotope effects and establishes the semiclassical boundaries of the
relationship. Studies on the mechanism of oxidosqualene cyclase involve the
determination of a large number of precise KIEs simultaneously. Transition state models
for the Sharpless asymmetric epoxidation have been developed that explain the
versatility, high selectivities, and ligand accelerated catalysis of the reaction. Theoretical
predictions on the proposed enzymatic mechanism of flavin dependent amine oxidation
suggest a hydride transfer mechanism and rules out mechanisms involving covalent
intermediates. Finally, a theoretical analysis of Diels-Alder reactions successfully
describes the unexpected exo selectivity in some of these reactions
Measuring Prefrontal Hemodynamic Responses Using Functional Near-Infrared Spectroscopy During Mobility for a Child With Motor Impairment
No full textAbstract
Date Presented 3/31/2017
This study used functional near-infrared spectroscopy (fNIRS) to identify changes in cognitive workload in a child with motor impairment during experiences with robot-assisted mobility. The study provides preliminary support for using fNIRS to measure cognitive workload in novel motor tasks.
Primary Author and Speaker: Kelly Cusick
Additional Authors and Speakers: Alexandra DiStasi, Stephanie Holowinski, Olivia Fitzpatrick
Contributing Authors: Megan Davis, Melody H. Wallace, Sharon A. Stansfield, Carole Dennis, Hélène M. Larin, Nancy Rader, Judith Pena-Shaff</jats:p
‘Enacted in the destiny of sedentary peoples’: racism, discovery and the grounds of law
No full textWhilst the racial, and racist, basis of the doctrine of discovery is a modern innovation, the doctrine owes much to its pre-modern forms and ethos. The finding and settlement of putatively unknown lands has long been attended with mythic and religious justification and with rituals of appropriation all of which strikingly resemble modern practice. Similarity in this case, however, serves to dramatize difference. What marks modern discovery of the occidental variety is the displacement of the mythic and religious by a combination of racism and legalism. The story of that displacement is told here along with an analysis of the poverty, not to say vacuity, of the doctrine of discovery as a justification for imperial appropriation. Since the story is told in broadly historical terms, its conception of the modern relies on the temporal ‘depth’ which historians usually attribute to this term, the discoveries of Columbus here providing something of a benchmark. But this account of the doctrine of discovery is not an antiquarian exercise, not a tale told in a now entirely discovered world, the unfolding of which may have had its reasons for regret but is now decidedly done with. Rather, this account is modern also in the sense of having current significance, of discovery’s still being an impelling force in the treatment of peoples supposedly once discovered and in the self-identity of those who would claim to have once discovered them, an identity which extends to the grounding of the discoverer’s law. Following the preponderant legal authority on discovery, my ‘case’ study here will come from the history of the United States. The parallels with the Australian situation are, it would seem, close
An oligonucleotide microarray for transcriptome analysis of Schistosoma mansoni and its application/use to investigate gender-associated gene expression
No full textGlobal profiling transcriptomes of parasitic helminths offers the potential to simultaneously identify co-ordinately expressed genes, novel genetic programs and uniquely utilized metabolic pathways, which together provide an extensive and new resource for vaccine and drug discovery. We have exploited this post-genomic approach to fabricate the first oligonucleotide DNA microarray for gene expression analysis of the parasitic trematode Schistosoma mansoni. A total of 17,329 S. mansoni DNA sequences were used to design a microarray consisting of 7335 parasite elements or approximately 50% of this parasite's transcriptome. Here, we describe the design of this new microarray resource and its evaluation by extending studies into gender-associated gene expression in adult schistosomes. We demonstrate a high degree of reproducibility in detecting transcriptional differences among biologically replicated experiments and the ability of the microarray to distinguish between the expression of closely related gene family members. Importantly, for issues related to sexual dimorphism, labour division, gamete production and drug target discovery, 197 transcripts demonstrated a gender-biased pattern of gene expression in the adult schistosome, greatly extending the number of sex-associated genes. These data demonstrate the power of this new resource to facilitate a greater understanding into the biological complexities of schistosome development and maturation useful for identifying novel intervention strategies
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