Results of the 2018 Rapid DNA Maturity Assessment

Three commercially available integrated rapid DNA instruments were tested as a part of a rapid DNA maturity assessment in July of 2018. The assessment was conducted with sets of blinded single-source reference samples provided to participants for testing on the individual rapid platforms within their laboratories. The data were returned to the National Institute of Standards and Technology (NIST) for review and analysis. Both FBI-defined automated review (Rapid DNA Analysis) and manual review (Modified Rapid DNA Analysis) of the datasets were conducted to assess the success of genotyping the 20 Combined DNA Index System (CODIS) core STR loci and full profiles generated by the instruments. Genotype results from the multiple platforms, participating laboratories, and STR typing chemistries were combined into a single analysis. The Rapid DNA Analysis resulted in a success rate of 80% for full profiles (85% for the 20 CODIS core loci) with automated analysis. Modified Rapid DNA Analysis resulted in a success rate of 90% for both the CODIS 20 core loci and full profiles (all attempted loci per chemistry). An analysis of the peak height ratios demonstrated that 95% of all heterozygous alleles were above 59% heterozygote balance. For base-pair sizing precision, the precision was below the standard 0.5 bp deviation for both the ANDE 6C System and the RapidHIT 200.

Developmental validation of the ANDE™ rapid DNA system with FlexPlex™ assay for arrestee and reference buccal swab processing and database searching

A developmental validation was performed to demonstrate reliability, reproducibility and robustness of the ANDE System with the FlexPlex assay, including an integrated Expert System, across a number of laboratories and buccal sample variations. Previously, the related DNAscan™/ANDE 4C Rapid DNA System using the PowerPlex^®16 assay and integrated Expert System Software received NDIS approval in March 2016. The enhanced ANDE instrument, referred to as ANDE 6C, and the accompanying 6-dye, 27-locus STR assay, referred to as FlexPlex, have been developed to be compatible with all widely used global loci, including the expanded set of the CODIS core 20 loci. Six forensic and research laboratories participated in the FlexPlex Rapid DNA developmental validation experiments, testing a total of 2045 swabs, including those obtained from 1387 unique individuals. The goal of this extensive and comprehensive validation was to thoroughly evaluate and document the ANDE System and its internal Expert System to reliably genotype reference buccal swab samples in a manner compliant with the FBI's Quality Assurance Standards and the NDIS Operational Procedures. The ANDE System, including automated Expert System analysis, generated reproducible and concordant results for buccal swabs when testing various instruments at different laboratories by a number of different operators. When testing a number of non-human DNAs, including oral bacteria, the ANDE System and FlexPlex assay demonstrated limited cross-reactivity. Potential PCR inhibitors were evaluated as part of the validation and no inhibition was detected. Reproducible and concordant profiles were generated from buccal swab samples collected with a limit of detection appropriate for buccal swab collections from arrestees. The precision and resolution of the System met industry standards for detection of microvariants and single base resolution. The integrated Expert System appropriately demonstrated the ability to correctly pass or fail profiles for CODIS upload without human review. During this comprehensive developmental validation, the ANDE System successfully interpreted over 2000 samples tested with over 99.99% concordant alleles. The data package described herein led to the ANDE System with the FlexPlex assay receiving NDIS approval in June 2018.

Developmental validation of the DNAscan™ Rapid DNA Analysis™ instrument and expert system for reference sample processing

Since the implementation of forensic DNA typing in labs more than 20 years ago, the analysis procedures and data interpretation have always been conducted in a laboratory by highly trained and qualified scientific personnel. Rapid DNA technology has the potential to expand testing capabilities within forensic laboratories and to allow forensic STR analysis to be performed outside the physical boundaries of the traditional laboratory. The developmental validation of the DNAscan/ANDE Rapid DNA Analysis System was completed using a BioChipSet™ Cassette consumable designed for high DNA content samples, such as single source buccal swabs. A total of eight laboratories participated in the testing which totaled over 2300 swabs, and included nearly 1400 unique individuals. The goal of this extensive study was to obtain, document, analyze, and assess DNAscan and its internal Expert System to reliably genotype reference samples in a manner compliant with the FBI's Quality Assurance Standards (QAS) and the NDIS Operational Procedures. The DNAscan System provided high quality, concordant results for reference buccal swabs, including automated data analysis with an integrated Expert System. Seven external laboratories and NetBio, the developer of the technology, participated in the validation testing demonstrating the reproducibility and reliability of the system and its successful use in a variety of settings by numerous operators. The DNAscan System demonstrated limited cross reactivity with other species, was resilient in the presence of numerous inhibitors, and provided reproducible results for both buccal and purified DNA samples with sensitivity at a level appropriate for buccal swabs. The precision and resolution of the system met industry standards for detection of micro-variants and displayed single base resolution. PCR-based studies provided confidence that the system was robust and that the amplification reaction had been optimized to provide high quality results. The DNAscan integrated Expert System was examined as part of the Developmental Validation and successfully interpreted the over 2000 samples tested with over 99.998% concordant alleles. The system appropriately flagged samples for human review and failed both mixed samples and samples with insufficient genetic information. These results demonstrated the integrated Expert System makes correct allele calls without human intervention.

ID: 113: THE ENDOTHELIAL PHD2/HIF-2 AXIS REGULATES PULMONARY ARTERY PRESSURE IN MICE

Background

Pulmonary hypertension (PH), a common clinical problem characterized by increased pulmonary artery (PA) pressure, is frequently triggered by hypoxia. Key mediators of cellular hypoxia responses are hypoxia-inducible factors (HIF)-1 and -2, the activity of which is regulated by prolyl-4-hydroxylase domain (PHD) proteins, with PHD2 being the main oxygen sensor that controls HIF activity under normoxia. Although both transcription factors are expressed in the lung, little is known about their cell type-specific roles in the pathogenesis of PH.

Methods and Results

Here we used a genetic approach to investigate the role of endothelial PHD2/HIF axis in the regulation of PA pressure. Endothelial cell specific HIF activation was achieved by crossing Vecadherin (Cdh5)-Cre transgenics to Phd2 floxed mice (ePhd2), while the contribution of each HIF isoform was assessed by generating double mutants lacking Phd2 and Hif-2 (ePhd2Hif2) or Phd2 and Hif-1 (Phd2Hif1). Right ventricular systolic pressure (RVSP) was measured via insertion of a 1.4F Mikro-tip catheter transducer into a surgically exposed right internal jugular vein. ePhd2 mice showed activation of HIF-signaling as shown by immunoblot analysis of lung tissue for HIF-1 and HIF-2. These mice developed spontaneous PH (RVSP, ePhd2: 54.3±6.9 vs Cre-: 24.8±2.2 mm Hg, P=0.005), which was associated with right ventricular hypertrophy (RVH) (Fulton Index, ePhd2: 0.52 vs Cre-: 0.28, P=0.0004) and early mortality. While morphologic analysis of ePhd2 lungs did not demonstrate plexiform or lumen-obliterating lesions, enhanced muscularization of peripheral PAs was detected in mutants compared to controls, as indicated by an increase in the number of arteries with diameters <100 µm that stained positive for αSMA (22.1±1.6 vs. 7.6±1.5 muscularized vessels/10 hpf, P<0.0001). The PH phenotype was maintained in ePhd2Hif1 mutants but was reversed in ePhd2Hif2 mutants. To assess the contribution of endothelial HIF-2 in hypoxia induced PH, endothelial Hif2 single mutants or Cre-littermates were exposed to normobaric hypoxia (10% O2) for 4 weeks. In contrast to controls, eHif2 mutants were protected from development of PH and RVH. Bone marrow transplantation studies showed no contribution from hematopoietic HIF-2 in hypoxia induced PH. Because hypoxia regulates endothelin 1 (EDN1), a potent vasoconstrictor but also apelin (APLN), a vasodilatory peptide acting through binding to the apelin G-protein-coupled receptor (APLNR), we assessed the role of endothelial HIF-2 axis in the regulation of these molecules. Endothelial deletion of Phd2 resulted in 6.4-fold induction of pulmonary Edn1 mRNA (P=0.029), but not Apln mRNA. In contrast, Aplnr was downregulated by 2.5-fold in ePhd2 mutants (P=0.037). A similar pattern of expression was detected in ePhd2Hif1 mice, whereas simultaneous deletion of Hif2a and Phd2 reversed these changes. To investigate the differences between acute and chronic hypoxia, we examined the effects of acute HIF activation on Edn1 and Apln/Aplnr gene expression in vivo. To model acute hypoxia, we subjected WT mice to 8% O2 for 48 hrs and maintained controls in room air. Acute hypoxia resulted in a 4.3-fold and 1.6-fold up-regulation of Edn1 and Apln transcripts respectively (P=0.0011 for Edn1, P=0.08 for Apln) while Aplnr was reduced by 4.3-fold (P=0.0005). We observed similar gene expression changes in mice treated with a prolyl-4-hydroxylase inhibitor (PHI) that results in global HIF activation.

Conclusions

Our studies identify endothelial HIF-2 as a key transcription factor in the pathogenesis of PH and suggest that HIF-2 regulates PA pressure by modulating the expression of vasoactive molecules. Our findings identify the PHD2/HIF2 axis as a potential target for PH therapies.

Effect of preoperative multimedia information on perioperative anxiety in patients undergoing procedures under regional anaesthesia

BACKGROUND

Provision of preoperative information can alleviate patients' anxiety. However, the ideal method of delivering this information is unknown. Video information has been shown to reduce patients' anxiety, although little is known regarding the effect of preoperative multimedia information on anxiety in patients undergoing regional anaesthesia.

METHODS

We randomized 110 patients undergoing upper or lower limb surgery under regional anaesthesia into the study and control groups. The study group watched a short film (created by the authors) depicting the patient's in-hospital journey including either a spinal anaesthetic or a brachial plexus block. Patients' anxiety was assessed before and after the film and 1 h before and within 8 h after their operation, using the Spielberger state trait anxiety inventory and a visual analogue scale.

RESULTS

There was no difference in state and trait anxiety between the two groups at enrollment. Women had higher baseline state and trait anxiety than men (P=0.02). Patients in the control group experienced an increase in state anxiety immediately before surgery (P<0.001), and patients in the film group were less anxious before operation than those in the control group (P=0.04). After operation, there was a decrease in state anxiety from baseline in both groups, but patients in the film group were less anxious than the control group (P=0.005).

CONCLUSIONS

Preoperative multimedia information reduces the anxiety of patients undergoing surgery under regional anaesthesia. This type of information is easily delivered and can benefit many patients.

Characterizing dose-response relationships in multiple cancer bioassays

In the evaluation of chemical compounds for carcinogenic risk, regulatory agencies such as the U.S. Environmental Protection Agency and National Toxicology Program (NTP) have traditionally fit a dose-response model to data from rodent bioassays, and then used the fitted model to estimate a Virtually Safe Dose or the dose corresponding to a very small increase (usually 10(-6)) in risk over background. Much recent interest has been directed at incorporating additional scientific information regarding the properties of the specific chemical under investigation into the risk assessment process, including biological mechanisms of cancer induction, metabolic pathways, and chemical structure and activity. Despite the fact that regulatory agencies are currently poised to allow use of nonlinear dose-response models based on the concept of an underlying threshold for nongenotoxic chemicals, there have been few attempts to investigate the overall relationship between the shape of dose-response curves and mutagenicity. Using data from an historical database of NTP cancer bioassays, the authors conducted a repeated-measures Analysis of the estimated shape from fitting extended Weibull dose-response curves. It was concluded that genotoxic chemicals have dose-response curves that are closer to linear than those for nongenotoxic chemicals, though on average, both types of compounds have dose-response curves that are convex and the effect of genotoxicity is small.