Publications by authors named "Downing T"

Article Synopsis
  • Cutaneous leishmaniasis caused by Leishmania tropica is prevalent in the Middle East, with documented cases of treatment failure and drug resistance linked to genetic mechanisms like SNPs and CNVs.
  • The study analyzed SNP and CNV patterns in 22 isolates from Afghanistan, Iran, and Syria, revealing a high frequency of SNPs, especially on chromosome 23 in Syrian isolates, and significant changes in CNV related to drug exposure.
  • Findings suggest that Leishmania tropica employs various genetic adaptations, including enhanced mechanisms for survival under drug pressure, indicating its resilience and ability to adapt to environmental and therapeutic challenges.
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Background: Surveillance for heart transplant rejection by endomyocardial biopsy is invasive and may yield false negatives. T1 and T2 mapping from cardiac magnetic resonance can demonstrate elevations with rejection. We sought to evaluate longitudinal changes in T1 and T2 mapping in pediatric patients with heart transplant.

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The 3d organization of the genome - in particular, which two regions of DNA are in contact with each other - plays a role in regulating gene expression. Several factors influence genome 3d organization. Nucleosomes (where ~ 100 basepairs of DNA wrap around histone proteins) also bend, twist and compactify chromosomal DNA, altering its polymer mechanics.

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  • Neonates with symptomatic tetralogy of Fallot (sTOF) often require early surgical intervention, which can involve either staged repair (SR) or primary repair (PR), but both strategies expose them to low-dose ionizing radiation that may raise cancer risk.
  • This study analyzed the cumulative radiation exposure and lifetime attributable risk (LAR) of cancer in sTOF patients who underwent either SR or PR, using data from 242 neonates across multiple centers.
  • Results showed that SR resulted in significantly higher radiation exposure compared to PR and highlighted an increased LAR of cancer, particularly for females, emphasizing the need to consider radiation risk when choosing treatment options for this vulnerable group.*
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  • * A survey of 79 program directors revealed notable differences in training pathways and case volumes, with a recommendation for trainees to complete at least 400 total cases, including 250 interventional cases.
  • * Ongoing mentorship is essential for mastering complex procedures, and external mentorship programs are suggested to enhance support for new interventionalists and improve patient care in congenital heart disease.
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Lumpy skin disease virus (LSDV) is a member of the capripoxvirus (CPPV) genus of the family. LSDV is a rapidly emerging, high-consequence pathogen of cattle, recently spreading from Africa and the Middle East into Europe and Asia. We have sequenced the whole genome of historical LSDV isolates from the Pirbright Institute virus archive, and field isolates from recent disease outbreaks in Sri Lanka, Mongolia, Nigeria and Ethiopia.

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Background And Aims: The Fontan palliation is the final stage of surgery for many children born with univentricular physiology. Almost all Fontan patients develop liver fibrosis which may eventually lead to cirrhosis and hepatocellular carcinoma (HCC). These are important causes of morbidity and mortality in these patients.

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β-N-methylamino-l-alanine (BMAA) has been shown to inhibit vesicular monoamine transporter 2 (VMAT2), thereby preventing the uptake of monoaminergic neurotransmitters into platelet dense granules and synaptic vesicles. The inhibition is hypothesized to be through direct association of BMAA with hydroxyl groupꟷcontaining amino acid residues in VMAT2. This study evaluated whether BMAA-induced inhibition of VMAT2 could be prevented directly by co-incubation of BMAA with amino acids, and if this protection was specific for BMAA inhibition of VMAT2.

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Article Synopsis
  • The study examines how the stiffness of the extracellular matrix influences chromatin organization and the efficiency of converting fibroblasts into neurons, finding optimal results at a stiffness of 20 kPa.
  • ATAC sequencing reveals that chromatin accessibility to neuronal genes peaks at this stiffness, while histone acetylation and histone acetyltransferase (HAT) activity are also maximized at 20 kPa, with inhibition of HAT activity negating the effects of matrix stiffness.
  • Changes in transporter proteins like G-actin and cofilin affect HAT's transport into the nucleus, showing a complex relationship between matrix stiffness and epigenetic regulation crucial for advances in cell engineering and regenerative medicine.
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The first mechanism of toxicity proposed for the cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) was excitotoxicity, and this was supported by numerous in vitro studies in which overactivation of both ionotropic and metabotropic glutamate receptors was reported. However, the excitotoxicity of BMAA is weak in comparison with other known excitotoxins and on par with that of glutamate, implying that to achieve sufficient synaptic concentrations of BMAA to cause classical in vivo excitotoxicity, BMAA must either accumulate in synapses to allow persistent glutamate receptor activation or it must be released in sufficiently high concentrations into synapses to cause the overexcitation. Since it has been shown that BMAA can be readily removed from synapses, release of high concentrations of BMAA into synapses must be shown to confirm its role as an excitotoxin in in vivo systems.

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Background: The main objective measure to assess the health of the Fontan circulation is the pressure measurement of the superior vena cava or pulmonary arteries. We reviewed the literature for benefits of measuring resting pressure in the Fontan circuit and explored whether dynamic measurement by volume loading or exercise has the potential to refine this diagnostic tool.

Methods: PubMed was searched for articles showing a relationship between resting post-operative central venous pressure or pulmonary artery pressure and Fontan failure.

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The Fontan Udenafil Exercise Longitudinal (FUEL) trial showed that treatment with udenafil was associated with improved exercise performance at the ventilatory anaerobic threshold in children with Fontan physiology. However, it is not known how the initiation of phosphodiesterase 5 inhibitor therapy affects heart rate and blood pressure in this population. These data may help inform patient selection and monitoring after the initiation of udenafil therapy.

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T1/T2 parametric mapping may reveal patterns of elevation ("hotspots") in myocardial diseases, such as rejection in orthotopic heart transplant (OHT) patients. This study aimed to evaluate the diagnostic accuracy of free-breathing (FB) multi-parametric SAturation recovery single-SHot Acquisition (mSASHA) T1/T2 mapping in identifying hotspots present on conventional Breath-held Modified Look-Locker Inversion recovery (BH MOLLI) T1 and T2-prepared balanced steady-state free-precession (BH T2p-bSSFP) maps in pediatric OHT patients. Pediatric OHT patients underwent noncontrast 1.

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Article Synopsis
  • Advances in omic technologies now allow for comprehensive measurement of molecular properties in biological samples through multi-omics integration.
  • This review focuses on various statistical and computational methods for reducing dimensions and analyzing datasets from one, two, or more omics sources.
  • It provides practical guidance, including links to R packages and experimental design strategies, to help researchers effectively utilize emerging multi-omics methods.
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The role of transcription factors and biomolecules in cell type conversion has been widely studied. Yet, it remains unclear whether and how intracellular mechanotransduction through focal adhesions (FAs) and the cytoskeleton regulates the epigenetic state and cell reprogramming. Here, it is shown that cytoskeletal structures and the mechanical properties of cells are modulated during the early phase of induced neuronal (iN) reprogramming, with an increase in actin cytoskeleton assembly induced by Ascl1 transgene.

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Wastewater surveillance offers a rapid evaluation of SARS-CoV-2 transmission in a community. We describe how a community group, the Yarmouth Wastewater Testing Team (YWTT), in Yarmouth, Maine, (population 8,990) utilized an asset-based community design framework to organize and manage a program to monitor SARS-CoV-2 RNA concentrations. From September 22, 2020 through June 8, 2021, the YWTT disseminated weekly reports of the wastewater results and reported COVID-19 cases within the Yarmouth postal code.

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Background: Lifetime radiation exposure for paediatric orthotopic heart transplant (OHT) patients is significant with cardiac catheterisation as the dominant source. Interventional cardiac magnetic resonance is utilised to obtain simultaneous, radiation-free haemodynamics and flow/function measurements. We sought to compare invasive haemodynamic measurements and radiation exposure in traditional cardiac catheterisation, to comprehensive interventional cardiac magnetic resonance.

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Article Synopsis
  • DNA methylation changes in autosomal dominant polycystic kidney disease (ADPKD) present a new treatment target, but the combination of DNA methylation inhibitors and ADPKD drugs like metformin and tolvaptan hasn't been thoroughly studied.* ! -
  • Researchers tested the combination of these drugs in 2D and 3D cystic kidney cells, discovering that the DNA methylation inhibitor 5-aza-2'-deoxycytidine (Aza) works well with metformin to lower cell growth and viability.* ! -
  • The study found significant changes in global methylation patterns, with hypomethylation at genes related to ADPKD and cancer, suggesting potential for improved treatments
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When calculating cardiac index (C.I.) by the Fick method, oxygen consumption (VO) is often unknown, so assumed values are typically used.

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Innate immune cells are responsible for eliminating foreign infectious agents and cellular debris, and their ability to perceive, respond to, and integrate biochemical and mechanical cues from their microenvironment eventually determines their behavior. In response to tissue injury, pathogen invasion, or a biomaterial implant, immune cells activate many pathways to initiate inflammation in the tissue. In addition to common inflammatory pathways, studies have demonstrated the role of the mechanosensitive proteins and transcriptional coactivators YAP and TAZ (YAP/TAZ) in inflammation and immunity.

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Esophageal pathologies such as atresia and benign strictures often require surgical reconstruction with autologous tissues to restore organ continuity. Complications such as donor site morbidity and limited tissue availability have spurred the development of acellular grafts for esophageal tissue replacement. Acellular biomaterials for esophageal repair rely on the activation of intrinsic regenerative mechanisms to mediate de novo tissue formation at implantation sites.

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The neurotoxic, non-proteinogenic amino acid β-N-methylamino-l-alanine (BMAA) has been implicated in the development of neurodegenerative diseases; however, the mechanism(s) and mode(s) of toxicity remain unclear. Similarities in the neuropathology and behavioural deficits of neonatal rats exposed to either BMAA or reserpine, a known vesicular monoamine transporter 2 (VMAT2) inhibitor, suggest a similar mode of action. The aims of this study were therefore to determine if BMAA could prevent the uptake of serotonin into dense granules via inhibition of VMAT2, and, if so, the type of inhibition caused by BMAA.

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Plasmids facilitate horizontal gene transfer, which enables the diversification of pathogens into new anatomical and environmental niches, implying that plasmid-encoded genes can cooperate well with chromosomal genes. We hypothesise that such mobile genes are functionally different to chromosomal ones due to this ability to encode proteins performing non-essential functions like antimicrobial resistance and traverse distinct host cells. The effect of plasmid-driven gene gain on protein-protein interaction network topology is an important question in this area.

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DNA methylation occurs predominantly on cytosine-phosphate-guanine (CpG) dinucleotides in the mammalian genome, and the methylation landscape is maintained over mitotic cell division. It has been posited that coupling of maintenance methylation activity among neighbouring CpGs is critical to stability over cellular generations; however, the mechanism is unclear. We used mathematical models and stochastic simulation to analyse data from experiments that probe genome-wide methylation of nascent DNA post-replication in cells.

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