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"Taylor, Rachel"
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West Nile virus spread in Europe: Phylogeographic pattern analysis and key drivers
2024
West Nile virus (WNV) outbreaks in birds, humans, and livestock have occurred in multiple areas in Europe and have had a significant impact on animal and human health. The patterns of emergence and spread of WNV in Europe are very different from those in the US and understanding these are important for guiding preparedness activities.
We mapped the evolution and spread history of WNV in Europe by incorporating viral genome sequences and epidemiological data into phylodynamic models. Spatially explicit phylogeographic models were developed to explore the possible contribution of different drivers to viral dispersal direction and velocity. A \"skygrid-GLM\" approach was used to identify how changes in environments would predict viral genetic diversity variations over time.
Among the six lineages found in Europe, WNV-2a (a sub-lineage of WNV-2) has been predominant (accounting for 73% of all sequences obtained in Europe that have been shared in the public domain) and has spread to at least 14 countries. In the past two decades, WNV-2a has evolved into two major co-circulating clusters, both originating from Central Europe, but with distinct dynamic history and transmission patterns. WNV-2a spreads at a high dispersal velocity (88km/yr-215 km/yr) which is correlated to bird movements. Notably, amongst multiple drivers that could affect the spread of WNV, factors related to land use were found to strongly influence the spread of WNV. Specifically, the intensity of agricultural activities (defined by factors related to crops and livestock production, such as coverage of cropland, pasture, cultivated and managed vegetation, livestock density) were positively associated with both spread direction and velocity. In addition, WNV spread direction was associated with high coverage of wetlands and migratory bird flyways.
Our results suggest that-in addition to ecological conditions favouring bird- and mosquito- presence-agricultural land use may be a significant driver of WNV emergence and spread. Our study also identified significant gaps in data and the need to strengthen virological surveillance in countries of Central Europe from where WNV outbreaks are likely seeded. Enhanced monitoring for early detection of further dispersal could be targeted to areas with high agricultural activities and habitats of migratory birds.
Journal Article
Implications of the presence of N-glycolylneuraminic acid in recombinant therapeutic glycoproteins
2010
Recombinant glycoproteins produced in animal cell lines often bear the nonhuman sialic acid
N
-glycolylneuraminic acid (Neu5Gc). Ghaderi
et al
. show that two monoclonal antibodies in clinical use differ with respect to addition of Neu5Gc and propose that drug developers should consider the consequences of the Neu5Gc modification.
Recombinant glycoprotein therapeutics produced in nonhuman mammalian cell lines and/or with animal serum are often modified with the nonhuman sialic acid
N
-glycolylneuraminic acid (Neu5Gc; refs.
1
,
2
). This documented contamination has generally been ignored in drug development because healthy individuals were not thought to react to Neu5Gc (ref.
2
). However, recent findings indicate that all humans have Neu5Gc-specific antibodies, sometimes at high levels
3
,
4
. Working with two monoclonal antibodies in clinical use, we demonstrate the presence of covalently bound Neu5Gc in cetuximab (Erbitux) but not panitumumab (Vectibix). Anti-Neu5Gc antibodies from healthy humans interact with cetuximab in a Neu5Gc-specific manner and generate immune complexes
in vitro
. Mice with a human-like defect in Neu5Gc synthesis generate antibodies to Neu5Gc after injection with cetuximab, and circulating anti-Neu5Gc antibodies can promote drug clearance. Finally, we show that the Neu5Gc content of cultured human and nonhuman cell lines and their secreted glycoproteins can be reduced by adding a human sialic acid to the culture medium. Our findings may be relevant to improving the half-life, efficacy and immunogenicity of glycoprotein therapeutics.
Journal Article
Repeated elevated plus maze trials as a measure for tracking within-subjects behavioral performance in rats (Rattus norvegicus)
by
Taylor, Rachel M.
,
Lowery-Gionta, Emily G.
,
Moore, Nicole L. T.
in
Animal behavior
,
Animal experimentation
,
Anxiety
2018
The elevated plus maze (EPM) is routinely used in neuroscience research to evaluate emotional behavior in rodents by measuring general exploratory performance and avoidance of the aversive open arms of the maze. According to standard practice, behavior on the EPM is evaluated during a single trial to avoid the possibility of habituation to the apparatus that would result in lost sensitivity of key outcome measures. However, this possibility has not been systematically evaluated across repeated trials or across different environmental conditions. In the current study, we assessed within-subject behavior on the EPM in adult male rats over thirteen trials (tested twice weekly) repeated under identical conditions. We also assessed within-subject behavior on the EPM in adult male rats under dim (1 lux in the closed arm) and lit (246 lux in the closed arm) environmental conditions. We found that measures of general performance (basic movements and total distanced travelled throughout the maze) were stable across repeated trials and environmental conditions. We found that measures of open arm avoidance (distance travelled in, time spent in and entries in to the open arm) varied across trials and environmental conditions and were sensitive to the lighting conditions of the initial test. Though measures of open arm avoidance did show a linear trend indicative of habituation across repeated trials, this effect was variable across trials. Notably, preference for the open arm over the closed arm (measured as % of time spent in the open arm) assessed among individual animals occurred rarely and was never observed on the group level across the thirteen repeated trials. Together, these data demonstrate that measures of general performance such as basic movements and total distance traveled are robust to repeated testing and changing environmental lighting conditions. In contrast, measures of open arm avoidance show habituation with repeated testing and are sensitive to changing environmental lighting conditions. Based on these results, we suggest that within-subjects repeated testing on the EPM is valid in well-controlled studies that include an untreated control group to account for inter-trial variability and habituation.
Journal Article
Selenoprotein Transcript Level and Enzyme Activity as Biomarkers for Selenium Status and Selenium Requirements in the Turkey (Meleagris gallopavo)
2016
The current National Research Council (NRC) selenium (Se) requirement for the turkey is 0.2 μg Se/g diet. The sequencing of the turkey selenoproteome offers additional molecular biomarkers for assessment of Se status. To determine dietary Se requirements using selenoprotein transcript levels and enzyme activities, day-old male turkey poults were fed a Se-deficient diet supplemented with graded levels of Se (0, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0 μg Se/g diet) as selenite, and 12.5X the vitamin E requirement. Poults fed less than 0.05 μg Se/g diet had a significantly reduced rate of growth, indicating the Se requirement for growth in young male poults is 0.05 μg Se/g diet. Se deficiency decreased plasma GPX3 (glutathione peroxidase), liver GPX1, and liver GPX4 activities to 2, 3, and 7%, respectively, of Se-adequate levels. Increasing Se supplementation resulted in well-defined plateaus for all blood, liver and gizzard enzyme activities and mRNA levels, showing that these selenoprotein biomarkers could not be used as biomarkers for supernutritional-Se status. Using selenoenzyme activity, minimum Se requirements based on red blood cell GPX1, plasma GPX3, and pancreas and liver GPX1 activities were 0.29-0.33 μg Se/g diet. qPCR analyses using all 10 dietary Se treatments for all 24 selenoprotein transcripts (plus SEPHS1) in liver, gizzard, and pancreas found that only 4, 4, and 3 transcripts, respectively, were significantly down-regulated by Se deficiency and could be used as Se biomarkers. Only GPX3 and SELH mRNA were down regulated in all 3 tissues. For these transcripts, minimum Se requirements were 0.07-0.09 μg Se/g for liver, 0.06-0.15 μg Se/g for gizzard, and 0.13-0.18 μg Se/g for pancreas, all less than enzyme-based requirements. Panels based on multiple Se-regulated transcripts were effective in identifying Se deficiency. These results show that the NRC turkey dietary Se requirement should be raised to 0.3 μg Se/g diet.
Journal Article
2723 Abdominal Aortic Aneurysm: An Uncommon Cause of Gastric Outlet Obstruction
2019
INTRODUCTION:Gastric outlet obstruction is a highly uncommon presentation for abdominal aortic aneurysm.CASE DESCRIPTION/METHODS:A 65 year old male with past medical history of AAA, HCV treated with Harvoni, GERD with gastritis, and HTN presented with intractable nausea and non-bloody, bilious vomiting for 6 hours associated with sudden onset generalized abdominal pain. Patient reports that he had been having regular bowel movements and passing flatus in the days leading up to presentation. GERD had been previously well-controlled with a PPI. Physical exam revealed a 5 cm pulsating mass in the epigastrium. CTA demonstrated gross distension of both the stomach and the proximal duodenum. The abdominal aortic aneurysm measured 5.2 cm by 4.2 cm and extended over 10 cm in length; an increasingly large false lumen was also noted. There was no other obstructing lesion appreciated on CT, either intra- or extra-luminal. The enlarging aortic aneurysm impinged upon and caused the obstruction of the distal duodenum.DISCUSSION:An expanding abdominal aortic aneurysm can compress the duodenum against the mesenteric artery or abdominal wall, causing gastric outlet obstruction; this obstruction leads to patients presenting with nausea and vomiting. Aortoduodenal syndrome was first described in 1905 by Osler. There are a few dozen case reports of aortoduodenal syndrome in the literature. Any patients presenting with protracted vomiting and pulsatile abdominal mass should raise suspicion for aortoduodenal syndrome. Abdominal tenderness and distension are not common findings in this syndrome. CT is required to rule out an alternative cause of duodenal obstruction; diagnosis may be confirmed with upper GI series with contrast or upper endoscopy. Patient should be initially optimized with gastric decompression, fluid resuscitation, and electrolyte correction before preceding to definitive treatment. Previously, gastric bypass was the general treatment prior to the introduction of surgical aortic repair. Aortic aneurysm repair is the mainstay of therapy with endovascular repair becoming increasingly common.
Journal Article
Cancer incidence, treatment, and survival in the prison population compared with the general population in England: a population-based, matched cohort study
2024
The growing and ageing prison population in England makes accurate cancer data of increasing importance for prison health policies. This study aimed to compare cancer incidence, treatment, and survival between patients diagnosed in prison and the general population.
In this population-based, matched cohort study, we used cancer registration data from the National Cancer Registration and Analysis Service in England to identify primary invasive cancers and cervical cancers in situ diagnosed in adults (aged ≥18 years) in the prison and general populations between Jan 1, 1998, and Dec 31, 2017. Ministry of Justice and Office for National Statistics population data for England were used to calculate age-standardised incidence rates (ASIR) per year and age-standardised incidence rate ratios (ASIRR) for the 20-year period. Patients diagnosed with primary invasive cancers (ie, excluding cervical cancers in situ) in prison between Jan 1, 2012, and Dec 31, 2017 were matched to individuals from the general population and linked to hospital and treatment datasets. Matching was done in a 1:5 ratio according to 5-year age group, gender, diagnosis year, cancer site, and disease stage. Our primary objectives were to compare the incidence of cancer (1998–2017); the receipt of treatment with curative intent (2012–17 matched cohort), using logistic regression adjusted for matching variables (excluding cancer site) and route to diagnosis; and overall survival following cancer diagnosis (2012–17 matched cohort), using a Cox proportional hazards model adjusted for matching variables (excluding cancer site) and route to diagnosis, with stratification for the receipt of any treatment with curative intent.
We identified 2015 incident cancers among 1964 adults (1556 [77·2%] men and 459 [22·8%] women) in English prisons in the 20-year period up to Dec 31, 2017. The ASIR for cancer for men in prison was initially lower than for men in the general population (in 1998, ASIR 119·33 per 100 000 person-years [95% CI 48·59–219·16] vs 746·97 per 100 000 person-years [742·31–751·66]), but increased to a similar level towards the end of the study period (in 2017, 856·85 per 100 000 person-years [675·12–1060·44] vs 788·59 per 100 000 person-years [784·62–792·57]). For women, the invasive cancer incidence rate was low and so ASIR was not reported for this group. Over the 20-year period, the incidence of invasive cancer for men in prison increased (incidence rate ratio per year, 1·05 [95% CI 1·04–1·06], during 1999–2017 compared with 1998). ASIRRs showed that over the 20-year period, overall cancer incidence was lower in men in prison than in men in the general population (ASIRR 0·76 [95% CI 0·73–0·80]). The difference was not statistically significant for women (ASIRR 0·83 [0·68–1·00]). Between Jan 1, 2012, and Dec 31, 2017, patients diagnosed in prison were less likely to undergo curative treatment than matched patients in the general population (274 [32·3%] of 847 patients vs 1728 [41·5%] of 4165; adjusted odds ratio (OR) 0·72 [95% CI 0·60–0·85]). Being diagnosed in prison was associated with a significantly increased risk of death on adjustment for matching variables (347 deaths during 2021·9 person-years in the prison cohort vs 1626 deaths during 10 944·2 person-years in the general population; adjusted HR 1·16 [95% CI 1·03–1·30]); this association was partly explained by stratification by curative treatment and further adjustment for diagnosis route (adjusted HR 1·05 [0·93–1·18]).
Cancer incidence increased in people in prisons in England between 1998 and 2017, with patients in prison less likely to receive curative treatments and having lower overall survival than the general population. The association with survival was partly explained by accounting for differences in receipt of curative treatment and adjustment for diagnosis route. Improved routine cancer surveillance is needed to inform prison cancer policies and decrease inequalities for this under-researched population.
UK National Institute for Health and Care Research, King's College London, and Strategic Priorities Fund 2019/20 of Research England via the University of Surrey.
Journal Article
Temperature variability is integrated by a spatially embedded decision-making center to break dormancy in Arabidopsis seeds
by
Johnston, Iain G.
,
Taylor, Rachel E.
,
Topham, Alexander T.
in
Abscisic acid
,
Arabidopsis
,
Biological Sciences
2017
Plants perceive and integrate information from the environment to time critical transitions in their life cycle. Some mechanisms underlying this quantitative signal processing have been described, whereas others await discovery. Seeds have evolved a mechanism to integrate environmental information by regulating the abundance of the antagonistically acting hormones abscisic acid (ABA) and gibberellin (GA). Here, we show that hormone metabolic interactions and their feedbacks are sufficient to create a bistable developmental fate switch in Arabidopsis seeds. A digital single-cell atlas mapping the distribution of hormone metabolic and response components revealed their enrichment within the embryonic radicle, identifying the presence of a decision-making center within dormant seeds. The responses to both GA and ABA were found to occur within distinct cell types, suggesting cross-talk occurs at the level of hormone transport between these signaling centers. We describe theoretically, and demonstrate experimentally, that this spatial separation within the decision-making center is required to process variable temperature inputs from the environment to promote the breaking of dormancy. In contrast to other noise-filtering systems, including human neurons, the functional role of this spatial embedding is to leverage variability in temperature to transduce a fate-switching signal within this biological system. Fluctuating inputs therefore act as an instructive signal for seeds, enhancing the accuracy with which plants are established in ecosystems, and distributed computation within the radicle underlies this signal integration mechanism.
Journal Article
Utilizing CMP-sialic acid analogs to unravel Neisseria gonorrhoeae lipooligosaccharide-mediated complement resistance and design novel therapeutics
2015
Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT) structure of lipooligosaccharide (LOS) is capped by the bacterial sialyltransferase, using host cytidine-5’-monophosphate (CMP)-activated forms of the nine-carbon nonulosonate (NulO) sugar N-acetyl-neuraminic acid (Neu5Ac), a sialic acid (Sia) abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH), an inhibitor of the alternative complement pathway, and by limiting classical pathway activation (“serum-resistance”). We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac) and pseudaminic acid (Pse5Ac7Ac), to define structural requirements of Sia-mediated serum-resistance. While all NulOs except Pse5Ac7Ac were incorporated into the LNnT-LOS, only Neu5Gc incorporation yielded high-level serum-resistance and FH binding that was comparable to Neu5Ac, whereas Neu5Ac9Az and Leg5Ac7Ac incorporation left bacteria fully serum-sensitive and did not enhance FH binding. Neu5Ac9Ac and Neu5Gc8Me rendered bacteria resistant only to low serum concentrations. While serum-resistance mediated by Neu5Ac was associated with classical pathway inhibition (decreased IgG binding and C4 deposition), Leg5Ac7Ac and Neu5Ac9Az incorporation did not inhibit the classical pathway. Remarkably, CMP-Neu5Ac9Az and CMP-Leg5Ac7Ac each prevented serum-resistance despite a 100-fold molar excess of CMP-Neu5Ac in growth media. The concomitant presence of Leg5Ac7Ac and Neu5Ac on LOS resulted in uninhibited classical pathway activation. Surprisingly, despite near-maximal FH binding in this instance, the alternative pathway was not regulated and factor Bb remained associated with bacteria. Intravaginal administration of CMP-Leg5Ac7Ac to BALB/c mice infected with gonorrhea (including a multidrug-resistant isolate) reduced clearance times and infection burden. Bacteria recovered from CMP-Leg5Ac7Ac-treated mice were sensitive to human complement ex vivo, simulating in vitro findings. These data reveal critical roles for the Sia exocyclic side-chain in gonococcal serum-resistance. Such CMP-NulO analogs may provide a novel therapeutic strategy against the global threat of multidrug-resistant gonorrhea.
Journal Article
Selenium requirements based on muscle and kidney selenoprotein enzyme activity and transcript expression in the turkey poult (Meleagris gallopavo)
by
Taylor, Rachel M.
,
Sunde, Roger A.
in
Biology and Life Sciences
,
Food and nutrition
,
Genetic aspects
2017
The current NRC selenium (Se) requirement for turkeys is 0.2 μg Se/g diet. We previously fed turkey poults a Se-deficient diet (0.005 μg Se/g) supplemented with 10 graded levels of Se (0, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0 μg Se/g as Na2SeO3, 5/treatment) for 4 wk, and found that the minimum dietary Se requirement was 0.3 μg Se/g based on selenoprotein enzyme activity in blood, liver, gizzard and pancreas. Because the turkey is primarily a production animal, we expanded this analysis to kidney, heart, breast and thigh. Se concentrations in Se-deficient poults were 5.0, 9.8, 33, and 15% of levels in poults fed 0.4 μg Se/g in liver, kidney, thigh and breast, respectively. Increasing Se supplementation resulted in hyperbolic response curves for all tissues; breakpoint analysis indicated minimum Se requirements of 0.34-0.36 μg Se/g based on tissue Se levels in liver, kidney and thigh. Similarly, GPX1 activity in muscle tissues and kidney responded hyperbolically to increasing dietary Se, reaching well-defined plateaus with breakpoints at 0.30-0.36 μg Se/g. Minimum Se requirements based on GPX4 activity were 0.30-0.32 μg Se/g for breast and thigh. Selenoprotein transcript expression decreased significantly in Se deficiency for only 2, 3, 5, and 6 mRNA in breast, thigh, heart, and kidney, respectively, out of 24 known avian selenoproteins. Se response curves for regulated selenoprotein transcripts were hyperbolic, and reached well-defined plateaus with breakpoints in a narrow range of 0.08-0.19 μg Se/g. No selenoprotein transcript was altered by supernutritional Se. In summary, these results clearly indicate that the NRC dietary Se requirement should be raised to 0.4 μg Se/g, at least for poults, to meet the nutritional needs of the young turkey. The Se response curve plateaus further show that limits for turkey supplementation with selenite could safely be raised to 0.5 μg Se/g diet.
Journal Article