Characterization of the Cytochromes P450-Dependent Hepatic Microsomal Monooxygenase System of the American Alligator, Alligator Mississippiensis: Influence of Xenobiotic Chemicals.

Alligator mississippiensis contains all of the components of the hepatic microsomal mixed function oxidase system. In general, basal and induced levels of P450 specific content, immunochemically detected abundance and examined activities are less than in mammals. In alligator at least two classes of P450s are inducible by xenobiotics: those induced by 3-methylcholanthrene (3MC) and those induced by phenobarbital (PB). PB and 3MC induce multiple P450 isoforms as detected by western blot and enzymatic analyses. The induced level of alkoxyphenoxazone O-dealkylation (AROD) was 10- to 100-fold lower in alligator than in rat, with the exception of phenylbenzyloxyphenoxazone O-dealkylation. In contrast to mammals methoxyphenoxazone and benzyloxyphenoxazone exhibited the greatest ability of AROD substrates to discriminate between 3MC- and PB-induced isoforms. Carbon monoxide binding, western blots, and enzymatic activity indicates that the PB and 3MC time-courses take at least 48-72 h to reach full induction, longer than found in mammals. In contrast to rat, aroclor and tetrachlorobiphenyl yielded faint induction in western blots and along with clofibrate exhibited only minor alterations in AROD activity. Clofibrate also failed to induce lauric acid hydroxylation, a CYP 4A activity. Classical inhibitors of P450 inhibited AROD activity of the expected P450 isoforms. While antibodies used across phylogenetic classes lost specificity they only crossreacted within a gene family. Western blot, enzymatic and N-terminal sequence analysis indicates that the purified PB-induced P450 is a CYP 2 family isoform. Whether alligator isoforms are transcriptionally regulated remains unanswered as northern blots were inconclusive. The contention that alligator CYP 1A isoforms are transcriptionally regulated is supported by the presence of Ah receptors. The markedly different responses to single and multiple xenobiotics, lower or absent activities, altered discrimination factors, loss of antibody specificity and slower rates of induction challenges the view of how reptiles respond to xenobiotics and the interpretation of P450 assays as biomarkers of environmental pollution. While indicating the presence of alligator P450s in several families, the number of isoforms present, the breadth of substrates and whether these P450s are alligator homologues/orthologues of mammalian isoforms remain to be established

Pediatric Cancer Genetics Research and an Evolving Preventive Ethics Approach for Return of Results after Death of the Subject

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115941/1/jlme12295.pd

The effect of DNA recovery on the subsequent quality of latent fingermarks: a pseudo operational trial

The recovery of fingermarks and DNA from the same location at a crime scene can be problematic because of contamination issues associated with powdering or laboratory-based visualisation processes and/or the perceived destructive impact of commonly employed ‘swabbing’ approaches to DNA recovery. Previous research in a controlled environment demonstrated that it was possible to recover DNA and latent fingermarks from the same location on various substrates when an adhesive approach to DNA recovery was used. The aim of this research was to conduct a pseudo-operational trial into the dual recovery of DNA and fingermarks using gel lifters for DNA recovery. Participants were asked to voluntarily and anonymously donate a wide variety of porous and non-porous substrates post handling. No instruction as to fingermark deposition nor environmental storage was provided. BVDA gel lifters were applied to the substrates to replicate DNA recovery followed by the application of fingermark visualisation processes. The number and quality of the fingermarks was established using a grading approach. Application factors were also investigated to consider the effects of user variation. The results demonstrated that it was possible to recover DNA and fingermarks considered to be capable of supporting an identification. Fingermark quality post lifting was dependant on the substrates used. The weight applied to the gel during its application was a lesser contributing factor than the duration of its contact with the surface. There was a greater chance of leaving the fingermarks unaltered with the application of a low weight and instantaneous retraction

DNA from Fingerprints: Attempting Dual Recovery

DNA and Fingerprints are highly prioritised evidence types as they are considered reliable when distinguishing between individuals within a population. Attempts have been documented on recovering both forms of evidence from a single source, but were met with varying success. These studies have however highlighted issues concerning interferences resulting from the methods used to either recover or visualise, with a significant issue lying with contamination or destruction of the DNA by fingerprint enhancement techniques. The aim of the research was to recover DNA prior to enhancement to determine the extent of recovery and damage of both the ridge detail and DNA. Fingerprints were deposited on textured plastic, carrier bags, glass, stainless steel and paper. DNA was recovered by the use of nylon flocked swabs (CopanTM), minitapes (ScenesafeTM) or gelatine lifts (Crime Scene Investigation LimitedTM). Extraction was conducted with QIAmp DNA micro kitTM (QIAGEN®), with Qubit® fluorometry being used for DNA quantification and NGM SelectTM (AmpFISTR®) determining the quality. For fingerprint enhancement; cyanoacrylate, aluminium powder and DFO were used to visualise the prints which were scored using the Centre of Applied Science and Technology (CAST) grading scheme. The gelatine lifts displayed higher detectable levels of DNA along with recovering more donor alleles. The lifts also resulted in the least amount of damage to ridge detail. Minitapes followed in both DNA levels and ridge damage. The nylons swabs displayed a low affinity for collecting DNA while removing all traces of the fingerprints

An evaluation of two adhesive media for the recovery of DNA from latent fingermarks: A preliminary study

Dual recovery of forensic evidence is beneficial for crime scene and evidence processing as it can potentially double the evidential value of a single source, even more so in instances of DNA fingermarks. The use of adhesive liftering media has shown comparable results to swabbing when dealing with trace DNA recovery. Gelatine lifters have displayed the potential to recover DNA from latent fingermarks with minimal alteration to friction ridge detail post application, yet their ability to recover DNA has not fully been explored. The aim of this research was to compare the use of gelatine lifters with more readily available masking tape in their ability to recover cellular material from latent fingermarks. Natural (n = 120) and sebaceous (n = 120) fingermarks were deposited and aged in time frames from fresh, 1-day, 2-day, 1-week, 2-weeks, and 1 month. DiamondTM Nucleic Acid Dye was used as a visualisation method for any DNA containing cellular material. Images of the fingermarks pre and post lifting, and on the lifting media were imaged using the DSC®5 system. The media’s ability to recover cellular material was assessed using fluorescent particle analysis by the employment of the free software ImageJ. Fluorescent particles could be observed on the lifting media post lifting with the use of DiamondTM Dye. Time was not seen to influence the variation in the number of fluorescent particles observed. The use of gelatine lifters was found to have a higher amount of recovered DNA containing cellular material than masking tape. Visualisation of particles on masking tape were inhibited by its porosity and absorption of the dye. Some fingermark detail could be observed in the gelatine lifters. The DSC®5 system was suitable for imaging fingermarks stained with DiamondTM Dye

Influence of anatomic correction for transposition of the great arteries on myocardial perfusion: Radionuclide imaging with technetium-99m 2-methoxy isobutyl isonitrile

AbstractObjectives. We sought to determine the incidence of late perfusion defects attributable to coronary artery mobilization in patients undergoing anatomic correction for complete transposition of the great arteries.Background. Anatomic correction (arterial switch procedure) is currently the surgical treatment of choice for complete transposition. From its conception, there has been concern about the impact on myocardial perfusion of the coronary artery mobilization and reimplantation involved in the correction. Previous studies have demonstrated myocardial perfusion defects in patients after correction, although a causal relation between coronary mobilization, and perfusion abnormality has not been established.Methods. In a case-comparison study designed to test this hypothesis, 29 children underwent imaging with technetium-99m 2-methoxy isobutyl isonitrile (technetium-99m mibi). Ten had undergone anatomic correction (arterial switch group; interval from operation 6.9 ± 1.42 years [range 4.9 to 9.1]); 9 had required noncoronary open heart surgery for other cardiac lesions (postbypass group; interval from operation 5.6 ± 3.6 years [range 1.0 to 13.25]); and 10 had had no surgical procedure (control group). The latter group comprised children with atrial or ventricular septal defects who required a radionuclide study for shunt calculation. Planar studies were performed in all 29 children, and additional tomographic acquisition was achieved in 25. To assess reversibility of perfusion defects both an exercise and a rest planar study were performed in the arterial switch group.Results. Perfusion abnormalities were observed in seven of the nine children in the postbypass group and in all 10 children in the arterial switch group. The frequency of perfusion defects in these two groups was similar, with at least 25% of the tomographic segments reported being abnormal. The control group had significantly fewer defects than the other two groups (p = 0.02), with only 8% of the tomographic segments judged to be abnormal. In all except one patient in the arterial switch group, the segments reported as abnormal on the planar exercise study were either abnormal or equivocal on the rest study, indicating a fixed abnormality.Conclusions. Although the precise etiology of these perfusion abnormalities cannot be defined from this study, these data suggest that their origin is related more to the insult of open heart surgery itself than to the coronary manipulation involved in the arterial switch procedure. The functional importance requires further study

On the alleged simplicity of impure proof

Roughly, a proof of a theorem, is “pure” if it draws only on what is “close” or “intrinsic” to that theorem. Mathematicians employ a variety of terms to identify pure proofs, saying that a pure proof is one that avoids what is “extrinsic,” “extraneous,” “distant,” “remote,” “alien,” or “foreign” to the problem or theorem under investigation. In the background of these attributions is the view that there is a distance measure (or a variety of such measures) between mathematical statements and proofs. Mathematicians have paid little attention to specifying such distance measures precisely because in practice certain methods of proof have seemed self- evidently impure by design: think for instance of analytic geometry and analytic number theory. By contrast, mathematicians have paid considerable attention to whether such impurities are a good thing or to be avoided, and some have claimed that they are valuable because generally impure proofs are simpler than pure proofs. This article is an investigation of this claim, formulated more precisely by proof- theoretic means. After assembling evidence from proof theory that may be thought to support this claim, we will argue that on the contrary this evidence does not support the claim

From bioavailability science to regulation of organic chemicals

The bioavailability of organic chemicals in soil and sediment is an important area of scientific investigation for environmental scientists, although this area of study remains only partially recognized by regulators and industries working in the environmental sector. Regulators have recently started to consider bioavailability within retrospective risk assessment frameworks for organic chemicals; by doing so, realistic decision-making with regard to polluted environments can be achieved, rather than relying on the traditional approach of using total-extractable concentrations. However, implementation remains difficult because scientific developments on bioavailability are not always translated into ready-to-use approaches for regulators. Similarly, bioavailability remains largely unexplored within prospective regulatory frameworks that address the approval and regulation of organic chemicals. This article discusses bioavailability concepts and methods, as well as possible pathways for the implementation of bioavailability into risk assessment and regulation; in addition, this article offers a simple, pragmatic and justifiable approach for use within retrospective and prospective risk assessment

Pioglitazone for secondary prevention after ischemic stroke and transient ischemic attack: Rationale and design of the Insulin Resistance Intervention after Stroke Trial

Background: Recurrent vascular events remain a major source of morbidity and mortality after stroke or transient ischemic attack (TIA). The IRIS Trial is evaluating an approach to secondary prevention based on the established association between insulin resistance and increased risk for ischemic vascular events. Specifically, IRIS will test the effectiveness of pioglitazone, an insulin-sensitizing drug of the thiazolidinedione class, for reducing the risk for stroke and myocardial infarction (MI) among insulin resistant, nondiabetic patients with a recent ischemic stroke or TIA. Design: Eligible patients for IRIS must have had insulin resistance defined by a Homeostasis Model Assessment-Insulin Resistance \u3e3.0 without meeting criteria for diabetes. Within 6 months of the index stroke or TIA, patients were randomly assigned to pioglitazone (titrated from 15 to 45 mg/d) or matching placebo and followed for up to 5 years. The primary outcome is time to stroke or MI. Secondary outcomes include time to stroke alone, acute coronary syndrome, diabetes, cognitive decline, and all-cause mortality. Enrollment of 3,876 participants from 179 sites in 7 countries was completed in January 2013. Participant follow-up will continue until July 2015. Summary: The IRIS Trial will determine whether treatment with pioglitazone improves cardiovascular outcomes of nondiabetic, insulin-resistant patients with stroke or TIA. Results are expected in early 2016