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Stretton B, Koovor JG, Hains L, Kleinig O, Tan S, Gupta AK, Ittimani M, Dwyer A, McNeil K, Chan W, Cusack M, O'Callaghan PG, Maddison J, Bacchi S. How will the artificial intelligence algorithm work within the constraints of this healthcare system? Intern Med J 2024; 54:190-191. [PMID: 38267379 DOI: 10.1111/imj.16308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 11/30/2023] [Indexed: 01/26/2024]
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Islam KT, Zhong S, Zakavi P, Chen Z, Kavnoudias H, Farquharson S, Durbridge G, Barth M, McMahon KL, Parizel PM, Dwyer A, Egan GF, Law M, Chen Z. Improving portable low-field MRI image quality through image-to-image translation using paired low- and high-field images. Sci Rep 2023; 13:21183. [PMID: 38040835 PMCID: PMC10692211 DOI: 10.1038/s41598-023-48438-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/27/2023] [Indexed: 12/03/2023] Open
Abstract
Low-field portable magnetic resonance imaging (MRI) scanners are more accessible, cost-effective, sustainable with lower carbon emissions than superconducting high-field MRI scanners. However, the images produced have relatively poor image quality, lower signal-to-noise ratio, and limited spatial resolution. This study develops and investigates an image-to-image translation deep learning model, LoHiResGAN, to enhance the quality of low-field (64mT) MRI scans and generate synthetic high-field (3T) MRI scans. We employed a paired dataset comprising T1- and T2-weighted MRI sequences from the 64mT and 3T and compared the performance of the LoHiResGAN model with other state-of-the-art models, including GANs, CycleGAN, U-Net, and cGAN. Our proposed method demonstrates superior performance in terms of image quality metrics, such as normalized root-mean-squared error, structural similarity index measure, peak signal-to-noise ratio, and perception-based image quality evaluator. Additionally, we evaluated the accuracy of brain morphometry measurements for 33 brain regions across the original 3T, 64mT, and synthetic 3T images. The results indicate that the synthetic 3T images created using our proposed LoHiResGAN model significantly improve the image quality of low-field MRI data compared to other methods (GANs, CycleGAN, U-Net, cGAN) and provide more consistent brain morphometry measurements across various brain regions in reference to 3T. Synthetic images generated by our method demonstrated high quality both quantitatively and qualitatively. However, additional research, involving diverse datasets and clinical validation, is necessary to fully understand its applicability for clinical diagnostics, especially in settings where high-field MRI scanners are less accessible.
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Chau MT, Agzarian M, Wilcox RA, Dwyer A, Bezak E, Todd G. Simple quantitative planimetric measurement of nigrosome-1 for clinical settings. J Neurol Sci 2023; 454:120857. [PMID: 37939625 DOI: 10.1016/j.jns.2023.120857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/22/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
INTRODUCTION Loss of MRI hyperintense signal in nigrosome-1 (assessed with susceptibility-weighted imaging) is a biomarker for Parkinson's disease (PD). Current clinical practice involves subjectively rating the appearance of nigrosome-1 which is challenging. The study aimed to test and compare a simple method for quantifying nigrosome-1 with the current subjective rating method. METHODS Two experienced neuroradiologists measured area of hyperintense signal in nigrosome-1 (quantitative method) and rated nigrosome-1 appearance (as normal, attenuated, or absent; subjective method) in 42 patients encompassing the full spectrum of nigrosome-1 integrity (21 patients aged 55.5 ± 20.9 years with Essential tremor (ET) and a subset of 21 patients aged 69.6 ± 8.6 years with PD). Neuroradiologists were blinded to each other's measurements, clinical notes, and patient group. RESULTS Both methods yielded a significant difference between the groups (PD vs ET; p < 0.001). Pooled (across sides) area of nigrosome-1 hyperintense signal was significantly smaller in the PD group (median = 2.1 mm2, range = 0-15.8 mm2) than ET group (median = 8.3 mm2, range = 0-15.7 mm2; p < 0.001). Inter-rater reliability was high to very high for both methods (subjective: weighted kappa = 0.640, p < 0.001; quantitative: W = 0.733, p = 0.004). Our primary hypothesis that area of nigrosome-1 hyperintense signal exhibits higher inter-rater reliability than subjective rating of nigrosome-1 appearance was not supported. CONCLUSION The simple quantitative method, used with subjectively rated nigrosome-1 appearance, may improve confidence in longitudinal clinical reporting, when nigrosome-1 is attenuated. However, further work on the incremental diagnostic value of planimetry and bias, repeatability and reproducibility are needed before it can be recommended in clinical practice.
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Dwyer A, Korlaet M, Callary SA, Robertson T, Smitham P, Solomon LB. Impact of computed tomography metal artifact reduction protocol on periprosthetic tissue characterization after total hip arthroplasty: A cadaveric study. J Orthop Res 2023; 41:657-662. [PMID: 35652835 DOI: 10.1002/jor.25391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/19/2022] [Accepted: 05/14/2022] [Indexed: 02/04/2023]
Abstract
Metal artifact reduction (MAR) has improved computed tomography (CT) imaging of total hip arthroplasty (THA) but the assessment of osteolysis and implant to bone contact relies on the accurate depiction of bone defects, cancellous bone, and cement. This study evaluates the impact of available single and dual-energy protocols on periprosthetic tissue characterization in a cadaveric phantom. Bilateral THA was performed on a fresh frozen cadaveric pelvis with simulated osteolytic cavities. CT acquisitions with projection-based MAR and noise equivalence were performed using single energy 140 kVp, single energy 150 kVp with 0.6 mm tin filtration, and dual-energy at 100/150 kVp with 0.6 mm tin filtration, from which simulated energies were extracted. Image subtraction, segmentation, region of interest histograms, and line profiles were used to characterize tissue density and separation. Tissue densities were heavily dependent on the energy profile of the protocol. Cancellous bone ranged from 182 to 45 HU and cement from 1012 to 131 HU using 140 kVp compared to dual-energy with weighted high energy tube, respectively. Spectral separation between cancellous bone, osteolytic defect, and cement was reduced for all protocols compared with 140 kVp. Spectral overlap was most severe using dual-energy with heavily weighted high-energy tubes. Dual-energy algorithms reduced trabecular contrast within the cancellous bone and cortical edge response. Although the dual-energy acquisition has been proposed as an additive to projection-based MAR techniques in THA, reduced density and contrast in clinically relevant periprosthetic tissue compared to 140 kVp single energy may limit its use in characterizing periprosthetic tissues.
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Terry M, Powell J, Gilmore WS, Way DP, Dwyer A, Bhanji F, Panchal AR. Deriving National Continued Competency Priorities for Emergency Medical Services Clinicians. PREHOSP EMERG CARE 2022; 27:439-448. [PMID: 36066437 DOI: 10.1080/10903127.2022.2120934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Objective: Continued competency is poorly defined in emergency medical services (EMS), with no established method for verifying continued competency at a national level. The objective of this project was to refine understanding of continued competency for EMS clinicians in the U.S. and establish priorities for developing competency assessments.Methods: A panel of EMS managers, educators, medical directors, and experts in competency assessment, simulation, and certification used a modified Delphi technique to address two questions: "What is the content for continued competency in EMS that should be assessed or verified?" (content) and "How should continued competency of EMS clinicians be demonstrated?" (process) The Delphi process was conducted through electronic conferencing and survey software over a 6-month period. In round one, panelists responded to open-ended prompts and their contributions were analyzed and categorized into themes by independent reviewers. In round two, the panel rated theme importance using five-point Likert-type scales. In round three, the panel ranked their top 10 themes, and in round four, the panel selected the most important themes for each of the two questions through consensus-building discussions. Descriptive statistics and thematic analyses were performed with Excel and STATA 16.Results: Fourteen invited experts participated in all Delphi activities. The panel contributed 70 content and 35 process items from the original prompts. Following thematic analysis, these contributions were reduced to 21 and 14 unique themes, respectively. The final top five prioritized themes for content important for continued competency included 1) airway, respiration, and ventilation, 2) patient assessment, 3) pharmacology, 4) pediatrics, and 5) management of time critical disease progressions. The final top five prioritized themes for the processes for continued competency assessment included 1) assessments of evidence-based practice, 2) performance-based assessments, 3) combined knowledge and skill assessments, 4) performance improvement over time, and 5) frequent, short knowledge assessments.Conclusion: This modified Delphi process identified priorities for content and assessment, laying the groundwork for EMS continued competency at a national level. These findings can be leveraged by national task forces to develop transparent and consistent guidelines for systems that verify continued competency related to certification, licensure, and local credentialing.
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Hubbard DK, Wambach JA, LaTuga MS, Dwyer A, Aurora S, Lorch SA, Akinbi HT. Identifying the essential knowledge and skills for Neonatal-Perinatal Medicine: a systematic analysis of practice. J Perinatol 2022; 42:1266-1270. [PMID: 35732728 DOI: 10.1038/s41372-022-01429-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 05/27/2022] [Accepted: 06/08/2022] [Indexed: 12/14/2022]
Abstract
The knowledge and skills expected for board certification in Neonatal-Perinatal Medicine (NPM) should reflect the clinical practice of neonatology. First, a 14-member panel of practicing neonatologists, convened by the American Board of Pediatrics (ABP), drafted a practice analysis document which identified the practice domains, tasks, knowledge, and skills deemed essential for clinical practice. NPM fellowship program directors provided feedback via online survey resulting in revisions to the document. During the second phase of the project, the panel organized testable knowledge areas into content domains and subdomains to update the existing ABP NPM content outline. All ABP board-certified neonatologists were asked to review via online survey, and results were used to guide final revisions to the content outline. The NPM practice analysis document and the updated NPM content outline should serve as helpful resources for educators, trainees, and practicing neonatologists.
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Seah RB, Mak WK, Bryant K, Korlaet M, Dwyer A, Bain GI. Four-dimensional computed tomography scan for dynamic elbow disorders: recommendations for clinical utility. JSES Int 2021; 6:182-186. [PMID: 35141694 PMCID: PMC8811401 DOI: 10.1016/j.jseint.2021.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Background Four-dimensional computed tomography (4D CT) is rapidly emerging as a diagnostic tool for the investigation of dynamic upper limb disorders. Dynamic elbow pathologies are challenging to diagnose, and at present, limitations exist in current imaging modalities Objective We aimed to assess the clinical utility of 4D CT in detecting potential dynamic elbow disorders. Methods Twenty-eight elbow joints from 26 patients with symptoms of dynamic elbow pathology were included in this study. They were first assessed by a senior orthopedic surgeon with subsequent qualitative data obtained via a Siemens Force Dual Source CT scanner (Erlangen, Germany), producing two- and three-dimensional “static” images and 4D dynamic “movie” images for assessment in each clinical scenario. Clinical assessment before and after scan was compared. Results Use of 4D CT scan resulted in a change of diagnosis in 16 cases (57.14%). This included a change in primary diagnosis in 2 cases (7.14%) and secondary diagnosis in 14 cases (50%). In 25 cases (89.29%), the 4D CT scan allowed us to understand the pathological anatomy in greater detail which led to a change in the management plan of 15 cases (53.57%). Conclusion 4D CT is a promising diagnostic tool in the management of dynamic elbow disorders and may be considered in clinical practice. Future studies need to compare it with other diagnostic modalities such as three-dimensional CT.
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Escagedo PD, Deal CL, Dwyer A, Hauschild M. Insulin Growth Factor 1 Predicts Central Precocious Puberty in Girls 6 to 8 Years-Old: A Retrospective Study. J Endocr Soc 2021. [PMCID: PMC8090603 DOI: 10.1210/jendso/bvab048.1347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Background: Central precocious puberty (CPP) in females is characterized by thelarche before 8 years of age. Evidence of reproductive axis activation confirms the diagnosis (basal serum LH ≥ 0.3 IU/L or luteinizing hormone-releasing hormone (LHRH)-stimulated LH ≥ 5 IU/L. Stimulation testing is the diagnostic gold standard but is time-consuming and costly. Serum levels of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) are increased in girls with CPP. Objective: To assess the utility of serum IGF-1 and IGFBP-3 in identifying CPP in girls aged 6 to 8 years old. Methods: The study was a single-center retrospective study. Girls with confirmed CPP (n=44) and isolated premature adrenarche/thelarche (PA/PT, n=16) had baseline biochemical profiling and LHRH stimulation testing. Serum IGF-1 and IGFBP-3 results were converted to standard deviation scores (SDS). Correlations were calculated and receiver operating characteristic curves were plotted. Results: Girls with CPP had higher basal and peak LH, IGF-1 SDS, and growth velocity (p<0.05). IGF-1 SDS correlated positively with basal and peak LH (p<0.05). IGF-1 SDS (1.75-2.15) differentiated CPP and PA/PT with 89% sensitivity and 56% specificity (basal LH) and 94% specificity and 55% sensitivity (peak LH). IGFBP-3 SDS did not differ between groups or by CPP parameters. Conclusions: In clinical practice, IGF-1 SDS may be an additional tool for identifying CPP in girls aged 6 to 8 years-old when baseline clinical and laboratory diagnostic criteria are inconclusive, possibly avoiding more invasive procedures.
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Mouron-Hryciuk J, Stoppa-Vaucher S, Busiah K, Bouthors T, Antoniou MC, Jacot E, Brusgaard K, Christesen HT, Hussain K, Dwyer A, Roth-Kleiner M, Hauschild M. Congenital hyperinsulinism: 2 case reports with different rare variants in ABCC8. Ann Pediatr Endocrinol Metab 2021; 26:60-65. [PMID: 32871644 PMCID: PMC8026340 DOI: 10.6065/apem.2040042.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/19/2020] [Indexed: 11/20/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is a rare glucose metabolism disorder characterized by unregulated secretion of insulin that leads to hyperinsulinemic hypoglycemia (HH). Most cases are caused by mutations in the KATP-channel genes ABCC8 and KCNJ11. We report 2 patients that experienced severe HH from the first day of life. Patient 1 developed midgut volvulus after initiating diazoxide and required intestinal resection. He was subsequently managed with a high-dose octreotide and glucose-enriched diet. Consistent with diffuse type CHI by 18F-dihydroxyphenylalanine positron emission tomography-computed tomography, genetic testing revealed a homozygous ABCC8 variant, c.1801G>A, p.(Val601Ile). The rare variant was previously reported to be diazoxide-responsive, and the patient responded well to diazoxide monotherapy, with clinical remission at 2 years of age. Patient 2 responded to diazoxide with spontaneous clinical remission at 15 months of age. However, an oral glucose tolerance test at 7 years of age revealed hyperinsulinism. Genetic testing revealed that the proband and several seemingly healthy family members harbored a novel, heterozygous ABCC8 variant, c.1780T>C, p.(Ser594Pro). Genetic findings identified previously unrecognized HH in the proband's mother. The proband's uncle had been diagnosed with monogenic ABCC8-diabetes and was successfully transitioned from insulin to glibenclamide therapy. We report findings of intestinal malrotation and volvulus occurring 2 days after initiation of diazoxide treatment. We also report a novel, heterozygous ABCC8 variant in a family that exhibited cases of CHI in infancy and HH and monogenic diabetes in adult members. The cases demonstrate the importance and clinical utility of genetic analyses for informing and guiding treatment and care.
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Arshad U, Pertinez H, Box H, Tatham L, Rajoli RK, Neary M, Sharp J, Valentijn A, Hobson J, Unsworth C, Dwyer A, Savage A, Mcdonald TO, Rannard SP, Curley P, Owen A. Optimisation and validation of a sensitive bioanalytical method for niclosamide. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.01.13.426426. [PMID: 33469585 PMCID: PMC7814822 DOI: 10.1101/2021.01.13.426426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The SARS-CoV-2 pandemic has spread at an unprecedented rate, and repurposing opportunities have been intensively studied with only limited success to date. If successful, repurposing will allow interventions to become more rapidly available than development of new chemical entities. Niclosamide has been proposed as a candidate for repurposing for SARS-CoV-2 based upon the observation that it is amongst the most potent antiviral molecules evaluated in vitro . To investigate the pharmacokinetics of niclosamide, reliable, reproducible and sensitive bioanalytical assays are required. Here, a liquid chromatography tandem mass spectrometry assay is presented which was linear from 31.25-2000 ng/mL (high dynamic range) and 0.78-100 ng/mL (low dynamic range). Accuracy and precision ranged between 97.2% and 112.5%, 100.4% and 110.0%, respectively. The presented assay should have utility in preclinical evaluation of the exposure-response relationship and may be adapted for later evaluation of niclosamide in clinical trials.
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Messina A, Pulli K, Santini S, Acierno J, Känsäkoski J, Cassatella D, Xu C, Casoni F, Malone SA, Ternier G, Conte D, Sidis Y, Tommiska J, Vaaralahti K, Dwyer A, Gothilf Y, Merlo GR, Santoni F, Niederländer NJ, Giacobini P, Raivio T, Pitteloud N. Neuron-Derived Neurotrophic Factor Is Mutated in Congenital Hypogonadotropic Hypogonadism. Am J Hum Genet 2020; 106:58-70. [PMID: 31883645 DOI: 10.1016/j.ajhg.2019.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/22/2019] [Indexed: 12/20/2022] Open
Abstract
Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by infertility and the absence of puberty. Defects in GnRH neuron migration or altered GnRH secretion and/or action lead to a severe gonadotropin-releasing hormone (GnRH) deficiency. Given the close developmental association of GnRH neurons with the olfactory primary axons, CHH is often associated with anosmia or hyposmia, in which case it is defined as Kallmann syndrome (KS). The genetics of CHH are heterogeneous, and >40 genes are involved either alone or in combination. Several CHH-related genes controlling GnRH ontogeny encode proteins containing fibronectin-3 (FN3) domains, which are important for brain and neural development. Therefore, we hypothesized that defects in other FN3-superfamily genes would underlie CHH. Next-generation sequencing was performed for 240 CHH unrelated probands and filtered for rare, protein-truncating variants (PTVs) in FN3-superfamily genes. Compared to gnomAD controls the CHH cohort was statistically enriched for PTVs in neuron-derived neurotrophic factor (NDNF) (p = 1.40 × 10-6). Three heterozygous PTVs (p.Lys62∗, p.Tyr128Thrfs∗55, and p.Trp469∗, all absent from the gnomAD database) and an additional heterozygous missense mutation (p.Thr201Ser) were found in four KS probands. Notably, NDNF is expressed along the GnRH neuron migratory route in both mouse embryos and human fetuses and enhances GnRH neuron migration. Further, knock down of the zebrafish ortholog of NDNF resulted in altered GnRH migration. Finally, mice lacking Ndnf showed delayed GnRH neuron migration and altered olfactory axonal projections to the olfactory bulb; both results are consistent with a role of NDNF in GnRH neuron development. Altogether, our results highlight NDNF as a gene involved in the GnRH neuron migration implicated in KS.
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Rockwell H, Mack M, Famula T, Sandmeyer L, Bauer B, Dwyer A, Lassaline M, Beeson S, Archer S, McCue M, Bellone RR. Genetic investigation of equine recurrent uveitis in Appaloosa horses. Anim Genet 2019; 51:111-116. [PMID: 31793009 DOI: 10.1111/age.12883] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2019] [Indexed: 01/05/2023]
Abstract
Equine recurrent uveitis (ERU) is characterized by intraocular inflammation that often leads to blindness in horses. Appaloosas are more likely than any other breed to develop insidious ERU, distinguished by low-grade chronic intraocular inflammation, suggesting a genetic predisposition. Appaloosas are known for their white coat spotting patterns caused by the leopard complex spotting allele (LP) and the modifier PATN1. A marker linked to LP on ECA1 and markers near MHC on ECA20 were previously associated with increased ERU risk. This study aims to further investigate these loci and identify additional genetic risk factors. A GWAS was performed using the Illumina Equine SNP70 BeadChip in 91 horses. Additive mixed model approaches were used to correct for relatedness. Although they do not reach a strict Bonferroni genome-wide significance threshold, two SNPs on ECA1 and one SNP each on ECA12 and ECA29 were among the highest ranking SNPs and thus warranted further analysis (P = 1.20 × 10-5 , P = 5.91 × 10-6 , P = 4.91 × 10-5 , P = 6.46 × 10-5 ). In a second cohort (n = 98), only an association with the LP allele on ECA1 was replicated (P = 5.33 × 10-5 ). Modeling disease risk with LP, age and additional depigmentation factors (PATN1 genotype and extent of roaning) supports an additive role for LP and suggests an additive role for PATN1. Genotyping for LP and PATN1 may help predict ERU risk (AUC = 0.83). The functional role of LP and PATN1 in ERU development requires further investigation. Testing samples across breeds with leopard complex spotting patterns and a denser set of markers is warranted to further refine the genetic components of ERU.
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Shehata M, Shalaby A, Ghazal M, Abou El-Ghar M, Badawy MA, Beache G, Dwyer A, El-Melegy M, Giridharan G, Keynton R, El-Baz A. EARLY ASSESSMENT OF RENAL TRANSPLANTS USING BOLD-MRI: PROMISING RESULTS. PROCEEDINGS. INTERNATIONAL CONFERENCE ON IMAGE PROCESSING 2019; 2019:1395-1399. [PMID: 34690556 DOI: 10.1109/icip.2019.8803042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Non-invasive evaluation of renal transplant function is essential to minimize and manage renal rejection. A computer-assisted diagnostic (CAD) system was developed to evaluate kidney function post-transplantation. The developed CAD system utilizes the amount of blood-oxygenation extracted from 3D (2D + time) blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to estimate renal function. BOLD-MRI scans were acquired at five different echo-times (2, 7, 12, 17, and 22) ms from 15 transplant patients. The developed CAD system first segments kidneys using the level-sets method followed by estimation of the amount of deoxyhemoglobin, also known as apparent relaxation rate (R2*). These R2* estimates were used as discriminatory features (global features (mean R2*) and local features (pixel-wise R2*)) to train and test state-of-the-art machine learning classifiers to differentiate between non-rejection (NR) and acute renal rejection. Using a leave-one-out cross-validation approach along with an artificial neural network (ANN) classifier, the CAD system demonstrated 93.3% accuracy, 100% sensitivity, and 90% specificity in distinguishing AR from non-rejection . These preliminary results demonstrate the efficacy of the CAD system to detect renal allograft status non-invasively.
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Tatham LM, Savage AC, Dwyer A, Siccardi M, Scott T, Vourvahis M, Clark A, Rannard SP, Owen A. Towards a Maraviroc long-acting injectable nanoformulation. Eur J Pharm Biopharm 2019; 138:92-98. [DOI: 10.1016/j.ejpb.2018.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/09/2018] [Accepted: 04/12/2018] [Indexed: 10/17/2022]
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Delaney A, Volochayev R, Meader B, Lee J, Almpani N, Noukelak G, Brooks B, Henkind J, Chalmers L, Law J, Williamson K, Jacobsen C, Buitrago TP, Silva OP, Chie-Hee C, Kaindl A, Anita R, steindl K, Garcia-Ortiz J, Bart L, Russell B, Prasad R, Mondal U, Reigstad HM, Clements S, Salnikov K, DiOrio N, Balasubramanian R, Dwyer A, Seminara S, Crowley W, Plummer L, Hall J, Graham J, Lin A, Shaw N. SUN-219 Human Congenital Arhinia Is Associated with GnRH Deficiency and Primary Testicular Defects. J Endocr Soc 2019. [PMCID: PMC6552745 DOI: 10.1210/js.2019-sun-219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Congenital arhinia (absent external nose) is an extremely rare mendelian disorder (<100 case reports in the past century) caused by heterozygous missense mutations in the gene SMCHD1. Arhinia is frequently accompanied by ocular and reproductive defects, a clinical triad which defines the Bosma arhinia microphthalmia syndrome (BAMS). The etiology and spectrum of reproductive defects in BAMS is unknown. We studied eleven subjects with arhinia or nasal hypoplasia (aged 18-53 yrs; 5 males) to assess endogenous luteinizing hormone (LH) secretion (n=11), a validated marker of GnRH, responsiveness to pulsatile GnRH (n=2), and non-reproductive phenotypes (n=11). Clinical data abstracted from questionnaires were analyzed in 33 additional international patients. Nearly every male demonstrated clinical and biochemical signs of severe congenital GnRH deficiency (CGD) including a history of microphallus and/or cryptorchidism, testicular volumes < 3 ml, hypogonadotropic hypogonadism (HH), low inhibin B levels, and apulsatile LH profiles; two young boys (studied from afar) had normal genitals but an absent mini-puberty of infancy was confirmed biochemically in one case. Pulsatile GnRH administered to one adult male and hCG to two others also revealed testicular resistance. Several females reported spontaneous breast bud development, but all had primary amenorrhea, small ovaries on pelvic ultrasound, HH, and apulsatile LH profiles. Pulsatile GnRH administered to one female induced ovulation on treatment day 21. Two females (studied from afar) reported normal thelarche and menstrual cycles. The 11 subjects studied in detail were completely anosmic with absent internal olfactory structures on brain MRI but normal hypothalamic-pituitary anatomy. Subjects with arhinia demonstrated some, but not all, non-reproductive phenotypes characteristic of Kallmann syndrome (KS) and/or CHARGE syndrome including dental agenesis (56%) and congenital mirror movements (CMMs; 50%); none had renal agenesis, severe congenital heart defects, or deafness. This study demonstrates for the first time that the hypogonadotropism observed in BAMS is indeed secondary to GnRH deficiency. In contrast to the male predominance (3-5:1) in KS, there is no sex bias in the incidence of BAMS. However, females may demonstrate partial or complete pubertal development whereas males are severely affected with some showing both hypothalamic and testicular defects. The combination of defects in the nasal skeleton, olfactory structures, and GnRH ontogeny point to aberrant development of the nasal placode in BAMS, yet the high prevalence of CMMs, a sign of misrouted commissural axons, suggests insults may occur even earlier in neurogenesis, at the neural plate border.
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Antoniou MC, Bouthors T, Xu C, Phan-Hug F, Elowe-Gruau E, Stoppa-Vaucher S, van der Sloot A, Acierno J, Cassatella D, Richard C, Dwyer A, Pitteloud N, Hauschild M. A novel CHD7 mutation in an adolescent presenting with growth and pubertal delay. Ann Pediatr Endocrinol Metab 2019; 24:49-54. [PMID: 30943680 PMCID: PMC6449621 DOI: 10.6065/apem.2019.24.1.49] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 07/31/2018] [Indexed: 11/22/2022] Open
Abstract
Mutations in the CHD7 gene, encoding for the chromodomain helicase DNA-binding protein 7, are found in approximately 60% of individuals with CHARGE syndrome (coloboma, heart defects, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities and/or hearing loss). Herein, we present a clinical case of a 14-year-old male presenting for evaluation of poor growth and pubertal delay highlighting the diagnostic challenges of CHARGE syndrome. The patient was born full term and underwent surgery at 5 days of life for bilateral choanal atresia. Developmental milestones were normally achieved. At age 14 his height and weight were -2.04 and -1.74 standard deviation score respectively. He had anosmia as well as prepubertal testes and micropenis (4 cm×1 cm). The biological profile showed low basal serum testosterone and gonadotropins (testosterone, 0.2 nmol/L; luteinizing hormone, 0.5 U/L; follicle-stimulating hormone, 1.3 U/L), and otherwise normal pituitary function and normal imaging of the hypothalamic-pituitary area. The constellation of choanal atresia, anosmia, mild dysmorphic features, micropenis and delayed puberty were suggestive of CHARGE syndrome. Targeted genetic testing of CHD7 was performed revealing a de novo heterozygous CHD7 mutation (c.4234T>G [p.Tyr1412Asp]). Further paraclinical investigations confirmed CHARGE syndrome. Despite the presence of suggestive features, CHARGE syndrome remained undiagnosed in this patient until adolescence. Genetic testing helps clarify the phenotypic and genotypic spectrum to facilitate diagnosis, thus promoting optimal follow-up, treatment, and appropriate genetic counselling.
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Leslie LK, Olmsted MG, Turner A, Carraccio C, Dwyer A, Althouse L. MOCA-Peds: Development of a New Assessment of Medical Knowledge for Continuing Certification. Pediatrics 2018; 142:peds.2018-1428. [PMID: 30510031 DOI: 10.1542/peds.2018-1428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/11/2018] [Indexed: 11/24/2022] Open
Abstract
The American Board of Pediatrics (ABP) certifies that general and subspecialty pediatricians meet standards of excellence established by their peers. Certification helps demonstrate that a general pediatrician or pediatric subspecialist has successfully completed accredited training and fulfills continuous certification requirements (Maintenance of Certification [MOC]). One current component of the MOC program is a closed-book examination administered at a secure testing center (ie, the MOC Part 3 examination). In this article, we describe the development of an alternative to this examination termed the "Maintenance of Certification Assessment for Pediatrics" (MOCA-Peds) during 2015-2016. MOCA-Peds was conceptualized as an online, summative (ie, pass/fail), continuous assessment of a pediatrician's knowledge that would also promote learning. The system would consist of a set number of multiple-choice questions delivered each quarter, with immediate feedback on questions, rationales clarifying correct and incorrect answers, references for further learning, and peer benchmarking. Questions would be delivered quarterly and taken at any time within the quarter in a setting with Internet connectivity and on any device. As part of the development process in 2015-2016, the ABP actively recruited pediatricians to serve as members of a yearlong user panel or single-session focus groups. Refinements to MOCA-Peds were made on the basis of their feedback. MOCA-Peds is being actively piloted with pediatricians in 2017-2018. The ABP anticipates an expected launch in January 2019 of MOCA-Peds for General Pediatrics, Pediatric Gastroenterology, Child Abuse, and Pediatric Infectious Diseases with launch dates for the remaining pediatric subspecialties between 2020 and 2022.
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Peterse E, Meester R, Siegel R, Chen J, Dwyer A, Ahnen D, Smith R, Zauber A, Lansdorp-Vogelaar I. The Impact of the Rising Colorectal Cancer Incidence in Young Adults on the Optimal Age to Start Screening in the US: A Microsimulation Analysis. J Glob Oncol 2018. [DOI: 10.1200/jgo.18.34900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: In 2016, the MISCAN-Colon model was used to inform the US Preventive Services Task Force (USPSTF) colorectal cancer (CRC) screening guidelines, which recommend screening from ages 50 to 75 years for average risk individuals. However, these models did not take into account the increase in CRC incidence below the age of 50 years. Aim: In this study, we reevaluated the optimal age to start screening, age to end screening and screening interval in light of the increase in CRC incidence observed in young adults. Methods: We adjusted the simulated lifetime CRC incidence in the MISCAN-Colon model to reflect the observed increase in young onset incidence. In line with the strong birth cohort effect, the current generation of 40-year-olds was assumed to carry forward escalated disease risk as they age. Life-years gained (benefit), the number of colonoscopies (burden) and the ratios of incremental burden to benefit (efficiency ratio) were projected for different screening strategies. Strategies differed with respect to test modality, ages to start screening (40, 45, 50), ages to stop screening (75, 80, 85), and screening intervals (depending on screening modality). We then determined the model-recommended strategies in a similar way as we did for the USPSTF, using similar efficiency ratio thresholds to the previously accepted efficiency ratio of 39 incremental colonoscopies per life-year gained. Results: The life-years gained and the number of colonoscopies for each colonoscopy strategy are plotted in Fig 1. Because of the higher CRC incidence, model-predicted life-years gained from screening increased compared with our previous analyses for the USPSTF. Consequently, the balance of burden to benefit of screening improved, with colonoscopy screening every 10 years starting at age 45 years resulting in an efficiency ratio of 32 incremental colonoscopies per life-year gained. Conclusion: This decision-analytic modeling approach suggests that based on the increase in young-onset CRC incidence, screening initiation at age 45 years has a favorable balance between screening benefits and burden. Screening until age 75 years with colonoscopy every 10 years, fecal immunochemical testing annually, flexible sigmoidoscopy every 5 years, and computed tomographic colonography every 5 years was recommended by the model as these strategies provided similar life-years gained at an acceptable screening burden.[Figure: see text]
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Helou N, Dwyer A, Shaha M, Zanchi A. Erratum to: Multidisciplinary management of diabetic kidney disease: a systematic review and meta-analysis. JBI DATABASE OF SYSTEMATIC REVIEWS AND IMPLEMENTATION REPORTS 2018; 16:1902. [PMID: 30204674 DOI: 10.11124/jbisrir-2017-003886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Singer-Berk M, Knickelbein KE, Vig S, Liu J, Bentley E, Nunnery C, Reilly C, Dwyer A, Drögemüller C, Unger L, Gerber V, Lassaline M, Bellone RR. Genetic risk for squamous cell carcinoma of the nictitating membrane parallels that of the limbus in Haflinger horses. Anim Genet 2018; 49:457-460. [PMID: 29999543 DOI: 10.1111/age.12695] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2018] [Indexed: 11/29/2022]
Abstract
Squamous cell carcinoma (SCC) is the most common cancer affecting the equine eye, with a higher incidence documented in Haflinger horses. Recently, a missense variant in the gene damage specific DNA binding protein 2 (DDB2, p.Thr338Met) on ECA12 was identified as a risk factor for the development of limbal SCC in Haflinger horses. SCC also occurs on the nictitating membrane; therefore, investigating the role of this missense variant in nictitating membrane SCC is warranted. In this study, a common ancestor was identified among Haflinger horses affected with limbal SCC or with nictitating membrane SCC, thus supporting a recessive risk factor for the development of cancer at both ocular locations. Analysis of genotype data from Haflinger horses with and without nictitating membrane SCC revealed that the same region on ECA12 associated with limbal SCC was also associated with nictitating membrane SCC (P < 2.04 × 10-5 ). Fine mapping of this locus using 25 cases and 49 controls supported the hypothesis that DDB2:c.1013C>T, p.Thr338Met, is a risk factor for nictitating membrane SCC, as 88% of our cases were homozygous for this variant and no other polymorphism was more strongly associated (P = 4.13 × 10-14 ). These data indicate that the genetic risk is the same for the development of both limbal and nictitating membrane SCC in Haflinger horses and validates utilization of genetic testing of the DDB2 variant for both clinical management and the guidance of mating decisions.
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Sposato LA, Lam Y, Karapetis C, Vatandoust S, Roy A, Hakendorf P, Dwyer A, de Fontgalland D, Hollington P, Wattchow D. Observation of "complete clinical response" in rectal cancer after neoadjuvant chemoradiation: The Flinders experience. Asia Pac J Clin Oncol 2018; 14:439-445. [PMID: 29932278 DOI: 10.1111/ajco.12993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 04/29/2018] [Indexed: 01/17/2023]
Abstract
AIM Observation with close follow-up ("watch and wait") is a recognized treatment option in patients who achieve a complete clinical response to long course chemoradiotherapy. This review of a prospective database aims to evaluate the clinical outcomes among patients with a complete clinical response managed with observation. METHODS A prospective study of 32 patients who achieved a complete clinical response was undertaken. The primary outcomes measured were overall and recurrence-free survival, and rate of organ preservation in patients who deferred immediate surgery. RESULTS Seven patients developed local regrowth over a median follow-up period of 38 months (range, 9-91 months). Median time to detection was 12 months. All seven underwent salvage surgery with complete surgical clearance. One patient developed combined local and systemic recurrence following a low anterior resection. Organ preservation was possible in 25 (78%) patients who sustained a complete clinical response with no evidence of local regrowth or disease recurrence. Among the patients who sustained a complete response, two developed isolated systemic disease. Overall and recurrence-free survival was 95.7% and 87.0%, respectively. CONCLUSION The majority of patients with rectal cancer who achieved a complete clinical response after chemoradiotherapy and managed with a "watch and wait" approach preserved their rectum and did not develop cancer relapse. Salvage surgery was achieved in all patients who developed local regrowth. The study supports a period of observation in rectal cancer patients who achieve a complete clinical response.
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Hodgetts T, Grenyer R, Greenhough B, McLeod C, Dwyer A, Lorimer J. The microbiome and its publics: A participatory approach for engaging publics with the microbiome and its implications for health and hygiene. EMBO Rep 2018; 19:embr.201845786. [PMID: 29777052 DOI: 10.15252/embr.201845786] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Helou N, Dwyer A, Shaha M, Zanchi A. Multidisciplinary management of diabetic kidney disease: a systematic review and meta-analysis. ACTA ACUST UNITED AC 2018; 14:169-207. [PMID: 27532796 DOI: 10.11124/jbisrir-2016-003011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The increasing prevalence of diabetes poses significant challenges to healthcare systems around the world. Diabetes is the leading cause of end-stage renal disease. Diabetic kidney disease (DKD) is becoming a global health concern because it is a progressive disease associated with major health complications and increased health costs. The treatment goals for DKD are to slow the progression of the renal disease and prevent cardiovascular events. Accordingly, patients are expected to adhere to prescribed treatments and manage a wide range of daily self-care activities. Multidisciplinary management of chronic diseases, like diabetes and kidney disease, has been suggested as a means to improve patients' adherence to treatment and enhance health-related outcomes. This systematic review of multidisciplinary management of DKD is an important step in evaluating if such a management approach is effective in delaying disease progression. OBJECTIVES The goal of this systematic review was to identify the best available evidence regarding multidisciplinary management of DKD and to determine if a multidisciplinary management of DKD can improve patient outcomes. Specifically the review question was: What is the impact of multidisciplinary management of DKD on patient outcomes? INCLUSION CRITERIA TYPES OF PARTICIPANTS The current review considered adults aged 18 years and older who had been diagnosed with type 1 or type 2 diabetes and chronic kidney disease. TYPES OF INTERVENTION(S)/PHENOMENA OF INTEREST The current review examined studies that compared multidisciplinary interventions with usual standard care in ambulatory settings for patients with DKD. OUTCOMES The current review considered studies with the following primary outcomes: kidney function, incidence of kidney failure, generic or specific health-related quality of life, patient self-care abilities, adherence to treatment recommendations or goals; and the following secondary clinical outcomes: mortality rates secondary to DKD, glycemic control, blood pressure (BP) control, lipid profile, incidence of cardiovascular disease/events, patient knowledge on diabetes or DKD, patient empowerment or self-efficacy, generic or specific patient satisfaction with care and patient healthcare utilization. TYPES OF STUDIES The current review will consider randomized and quasi-experimental trials but included only randomized controlled trials (RCTs). SEARCH STRATEGY A three-step search strategy was utilized starting with a search of MEDLINE and CINAHL for the identification of keywords, followed by a search using keywords and index terms across MEDLINE, CINAHL and Embase databases and clinical trials registry platforms, and finally a search of the reference list of all identified papers. Studies published from the time of the respective database inception to November 2014 in English, German and French were considered. METHODOLOGICAL QUALITY Two independent reviewers assessed the methodological validity of the papers prior to inclusion in the review using the standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). DATA EXTRACTION Data were extracted from papers included in the review using the standardized data extraction tool from JBI-MAStARI. DATA SYNTHESIS Quantitative data were pooled using the RevMan 5 software for kidney function using estimated Glomerular Filtration Rate (eGFR), glycated hemoglobin, BP and total cholesterol (TC). Results were considered significant for P < 0.05. RESULTS Three RCTs were included in this review. Meta-analysis showed that multidisciplinary management was associated with a statistically significant improvement of glycated hemoglobin as compared with standard usual care (Relative Risk [RR] -0.49, at 95% confidence interval [CI] -0.83, -0.16, P < 0.01). The meta-analysis for eGFR showed a tendency to favor standard care; however, this finding cannot be conclusive because the CI was too wide (RR -3.30, at 95% CI -6.55, -0.05, P = 0.05). Meta-analysis results for BP and TC failed to show a difference between the multidisciplinary management of DKD and the usual standard care. Only one study measured patient-oriented primary and secondary outcomes and showed an improvement in health-related quality of life, patient self-care abilities, patient level of knowledge on diabetes and exercise self-efficacy. CONCLUSION Multidisciplinary management of DKD has the potential for improving glycemic control and thus preventing complications. Its effect on other clinical and patient-oriented outcomes, especially on delaying the progression of the disease through preserving and preventing the decline in kidney function, has yet to be determined. There is not enough evidence to recommend multidisciplinary management for preserving kidney function. Further studies are needed.
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