Publications by authors named "Ian Jackson"

is a fungal pathogen that can present as an opportunistic cause of pneumonia and can occur in individuals with various causes of immunosuppression, including malignancy and treatments for malignancy that confer increased risk. Although the guidelines for use of prophylaxis in certain populations are clear, the rapid development of novel cancer therapies elicits the need to accurately assess the degree of immunosuppression conferred by these regimens and to determine if patients receiving these therapies warrant prophylaxis. We present 2 cases of pneumonia in patients with invasive ductal carcinoma of the breast treated with a dose-dense chemotherapy regimen consisting of doxorubicin, cyclophosphamide, and paclitaxel.

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This article adopts a multidisciplinary approach, including surgery, oncology, radiology and patient perspectives, to discuss the key points of debate surrounding a watch and wait approach. In an era of shared decision-making, discussion of watch and wait as an option in the context of complete clinical response is appropriate, although it is not the gold standard treatment. Key challenges are the difficulty in assessing for a complete clinical response, prediction of recurrence and access to timely diagnostics for surveillance.

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Genetic approaches that allow lineage tracing are essential to our future understanding of melanocytes and melanoma. To date, the approaches used to label melanocytes in mice have relied on random integration of transgenes driven by the promoters of the Tyrosinase and Dopachrome tautomerase genes, knock-in to the Dopachrome tautomerase locus or knock-in to the Mlana locus in a bacterial artificial chromosome. These strategies result in expression in other tissues such as telencephalon and other cell types such as nerves.

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Anophthalmia (missing eye) describes a failure of early embryonic ocular development. Mutations in a relatively small set of genes account for 75% of bilateral anophthalmia cases, yet 25% of families currently are left without a molecular diagnosis. Here, we report our experimental work that aimed to uncover the developmental and genetic basis of the anophthalmia characterising the X-linked (eye-ear reduction) X-ray-induced allele in mouse that was first identified in 1947.

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We have recently identified encoding dopachrome tautomerase (DCT) as the eighth gene for oculocutaneous albinism (OCA). Patients with loss of function of suffer from eye hypopigmentation and retinal dystrophy. Here we investigate the eye phenotype in mice.

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Background: Right heart thrombus or clot in transit is a rare venous thromboembolism (VTE) with high mortality. COVID-19 infection has been associated with increased risk of such events. We present the case of a 63-year-old man with no traditional VTE risk factors who was diagnosed with a clot in transit three weeks after diagnosis of COVID-19.

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Eye color is highly variable in populations with European ancestry, ranging from low to high quantities of melanin in the iris. Polymorphisms in the locus have the largest effect on eye color in these populations, although other genomic regions also influence eye color. We performed genome-wide association studies of eye color in a Canadian cohort of European ancestry (N = 5,641) and investigated candidate causal variants.

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Background & Aims: Resistance to single cytokine blockade, namely anti-tumor necrosis factor (TNF) therapy, is a growing concern for patients with inflammatory bowel disease (IBD). The transcription factor T-bet is a critical regulator of intestinal homeostasis, is genetically linked to mucosal inflammation and controls the expression of multiples genes such as the pro-inflammatory cytokines interferon (IFN)-γ and TNF. Inhibiting T-bet may therefore offer a more attractive prospect for treating IBD but remains challenging to target therapeutically.

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Objectives: In this study, we aimed to determine the correlation between procalcitonin (PCT) levels and clinical outcomes including in-hospital mortality, intensive care unit (ICU) length of stay, and hospital length of stay in patients hospitalized with COVID-19.

Methods: Clinical, laboratory, and demographic data of 223 patients who met inclusion criteria were analyzed. PCT measurements of 0.

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Article Synopsis
  • - T-bet is a key transcription factor for CD4 T 1 cells and is also present in other CD4 T cell types, but its role in their differentiation and function is not fully understood.
  • - To investigate T-bet expression, researchers tracked its presence using a special mouse model, revealing a unique subset of CD4 T cells that show naïve cell features while being distinct from traditional naïve and memory T cells.
  • - These T-bet-experienced cells are inclined to develop into T 1 cells, produce a specific cytokine called IFN-γ upon activation, and are less likely to change into other T cell types, indicating that lineage factors can influence T cell responses even without standard activation markers.
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Background: Chylopericardium is the accumulation of lymphatic fluid in the pericardial cavity. It can be idiopathic or secondary to trauma, cardiothoracic surgery, neoplasm, radiation, tuberculosis, lymphatic duct dysfunction, thrombosis, or other causes. We present a case of chylopericardium due to subclavian vein thrombosis in a patient with protein S deficiency.

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Brittle cornea syndrome (BCS) is a rare recessive condition characterised by extreme thinning of the cornea and sclera. BCS results from loss-of-function mutations in the poorly understood genes ZNF469 or PRDM5. In order to determine the function of ZNF469 and to elucidate pathogenic mechanisms, we used genome editing to recapitulate a human ZNF469 BCS mutation in the orthologous mouse gene Zfp469.

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Oculocutaneous albinism (OCA) is a heritable disorder of pigment production that manifests as hypopigmentation and altered eye development. Exon sequencing of known OCA genes is unsuccessful in producing a complete molecular diagnosis for a significant number of affected individuals. We sequenced the DNA of individuals with OCA using short-read custom capture sequencing that targeted coding, intronic, and noncoding regulatory regions of known OCA genes, and genome-wide association study-associated pigmentation loci.

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Background: Hypokalemic periodic paralysis is a rare neuromuscular disorder characterized by transient episodes of flaccid paralysis due to a defect in muscle ion channels. Most cases are hereditary, but it can be acquired. We present a case of acquired hypokalemic periodic paralysis associated with hyperthyroidism and renal tubular acidosis.

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Background And Aims: Differential responsiveness to interleukin [IL]-2 between effector CD4+ T cells [Teff] and regulatory T cells [Treg] is a fundamental mechanism of immunoregulation. The single nucleotide polymorphism [SNP] rs61839660, located within IL2RA [CD25], has been associated with the development of Crohn's disease [CD]. We sought to identify the T cell immune phenotype of IBD patients who carry this SNP.

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Innate lymphoid cells are central to the regulation of immunity at mucosal barrier sites, with group 2 innate lymphoid cells (ILC2s) being particularly important in type 2 immunity. In this study, we demonstrate that microRNA(miR)-142 plays a critical, cell-intrinsic role in the homeostasis and function of ILC2s. Mice deficient for miR-142 expression demonstrate an ILC2 progenitor-biased development in the bone marrow, and along with peripheral ILC2s at mucosal sites, these cells display a greatly altered phenotype based on surface marker expression.

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Variants in the LIM homeobox transcription factor 1-beta () gene predispose individuals to elevated intraocular pressure (IOP), a key risk factor for glaucoma. However, the effect of mutations varies widely between individuals. To better understand the mechanisms underlying LMX1B-related phenotypes and individual differences, we backcrossed the (also known as ) allele onto the C57BL/6J (B6), 129/Sj (129), C3A/BLiA- /J (C3H) and DBA/2J- (D2-G) mouse strain backgrounds.

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Upon activation T cells engage glucose metabolism to fuel the costly effector functions needed for a robust immune response. Consequently, the availability of glucose can impact on T cell function. The glucose concentrations used in conventional culture media and common metabolic assays are often artificially high, representing hyperglycaemic levels rarely present in vivo.

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Purpose: Albinism is a clinically and genetically heterogeneous condition. Despite analysis of the 20 known genes, ~30% patients remain unsolved. We aimed to identify new genes involved in albinism.

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Prenatal testosterone (T)- treated female sheep manifest juvenile insulin resistance, post-pubertal increase in insulin sensitivity and return to insulin resistance during adulthood. Since compensatory hyperinsulinemia is associated with insulin resistance, altered pancreatic islet ontogeny may contribute towards metabolic defects. To test this, pregnant sheep were treated with or without T propionate from days 30-90 of gestation and pancreas collected from female fetuses at gestational day 90 and female offspring at 21 months-of-age.

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Organ transplantation is often lifesaving, but the long-term deleterious effects of combinatorial immunosuppression regimens and allograft failure cause significant morbidity and mortality. Long-term graft survival in the absence of continuing immunosuppression, defined as operational tolerance, has never been described in the context of multiple major histocompatibility complex (MHC) mismatches. Here, we show that miR-142 deficiency leads to indefinite allograft survival in a fully MHC mismatched murine cardiac transplant model in the absence of exogenous immunosuppression.

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The precise control of eye size is essential for normal vision. TMEM98 is a highly conserved and widely expressed gene which appears to be involved in eye size regulation. Mutations in human TMEM98 are found in patients with nanophthalmos (very small eyes) and variants near the gene are associated in population studies with myopia and increased eye size.

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