231 research outputs found
Renal drug metabolism in humans: the potential for drug–endobiotic interactions involving cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT)
This item is under embargo for a period of 12 months from the date of publication, in accordance with the publisher's policy.
‘This is the peer reviewed version of the following article:
Knights, K. M., Rowland, A. and Miners, J. O. (2013), Renal
drug metabolism in humans: the potential for drug–
endobiotic interactions involving cytochrome P450 (CYP)
and UDP-glucuronosyltransferase (UGT). British Journal of
Clinical Pharmacology, 76: 587–602, which has been
published in final form at doi:10.1111/bcp.12086. This
article may be used for non-commercial purposes in
accordance With Wiley Terms and Conditions for selfarchiving'.Although knowledge of human renal cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes and their role in xenobiotic and endobiotic metabolism is limited compared with hepatic drug and chemical metabolism, accumulating evidence indicates that human kidney has significant metabolic capacity. Of the drug metabolizing P450s in families 1 to 3, there is definitive evidence for only CYP 2B6 and 3A5 expression in human kidney. CYP 1A1, 1A2, 1B1, 2A6, 2C19, 2D6 and 2E1 are not expressed in human kidney, while data for CYP 2C8, 2C9 and 3A4 expression are equivocal. It is further known that several P450 enzymes involved in the metabolism of arachidonic acid and eicosanoids are expressed in human kidney, CYP 4A11, 4F2, 4F8, 4F11 and 4F12. With the current limited evidence of drug substrates for human renal P450s drug–endobiotic interactions arising from inhibition of renal P450s, particularly effects on arachidonic acid metabolism, appear unlikely. With respect to the UGTs, 1A5, 1A6, 1A7, 1A9, 2B4, 2B7 and 2B17 are expressed in human kidney, whereas UGT 1A1, 1A3, 1A4, 1A8, 1A10, 2B10, 2B11 and 2B15 are not. The most abundantly expressed renal UGTs are 1A9 and 2B7, which play a significant role in the glucuronidation of drugs, arachidonic acid, prostaglandins, leukotrienes and P450 derived arachidonic acid metabolites. Modulation by drug substrates (e.g. NSAIDs) of the intrarenal activity of UGT1A9 and UGT2B7 has the potential to perturb the metabolism of renal mediators including aldosterone, prostaglandins and 20-hydroxyeicosatetraenoic acid, thus disrupting renal homeostasis
Risks and responsibilities in establishing a wireless network for an educational institution
A wireless network solution is generally implemented when the bounds of walls of buildings and the constraints of wires need to be broken. Wireless technologies provide the potential for freedom of mobility which is undoubtedly a convenience for organisations in today’s market. The security of a wireless network is crucial for data integrity, especially when the data is not secured by the insulation of wires. While data is being transferred across a wireless network, it is vulnerable. There is no room for error, neglect or ignorance from an organisation, as a breech of data integrity can be devastating for both businesses and institutions. Securing a wireless network needs to be treated as mandatory for educational institutions, and not just as best practice. With both legal and financial consequences for a breech of data integrity and the data protection act, education institutions need to realise the legal obligations and liabilities they face with respect to the sensitive data and information traversing their network
Modeling and experimental characterization of stepped and v-shaped {311} defects in silicon
Producción CientíficaWe propose an atomistic model to describe extended {311} defects in silicon. It is based on the combination of interstitial and bond defect chains. The model is able to accurately reproduce not only planar {311} defects but also defect structures that show steps, bends, or both. We use molecular dynamics techniques to show that these interstitial and bond defect chains spontaneously transform into extended {311} defects. Simulations are validated by comparing with precise experimental measurements on actual {311} defects. The excellent agreement between the simulated and experimentally derived structures, regarding individual atomic positions and shape of the distinct structural {311} defect units, provides strong evidence for the robustness of the proposed model.Ministerio de Ciencia e Innovación (Proyect TEC2011-27701
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Souporcell: robust clustering of single-cell RNA-seq data by genotype without reference genotypes.
Methods to deconvolve single-cell RNA-sequencing (scRNA-seq) data are necessary for samples containing a mixture of genotypes, whether they are natural or experimentally combined. Multiplexing across donors is a popular experimental design that can avoid batch effects, reduce costs and improve doublet detection. By using variants detected in scRNA-seq reads, it is possible to assign cells to their donor of origin and identify cross-genotype doublets that may have highly similar transcriptional profiles, precluding detection by transcriptional profile. More subtle cross-genotype variant contamination can be used to estimate the amount of ambient RNA. Ambient RNA is caused by cell lysis before droplet partitioning and is an important confounder of scRNA-seq analysis. Here we develop souporcell, a method to cluster cells using the genetic variants detected within the scRNA-seq reads. We show that it achieves high accuracy on genotype clustering, doublet detection and ambient RNA estimation, as demonstrated across a range of challenging scenarios.We acknowledge the Wellcome Sanger Institute’s DNA Pipelines for construction of the 10x sequencing libraries. We thank Allan Muhwezi and Andrew Russell for assistance with parasite culture and 10x Single-cell 3’ RNA-seq respectively. In addition, we would like to thank Matthew Young for useful conversations about ambient RNA, Mirjana Efremova for providing information about the maternal/fetal data, and Katie Gray for assistance in interpreting the previously unannotated cluster. The Wellcome Sanger Institute is funded by the Wellcome Trust (grant 206194/Z/17/Z), which supports MKNL
and MH. This work was supported by an MRC Career Development Award (G1100339) to MKNL. We would like to acknowledge the Wellcome Trust Sanger Institute as the source of the human induced pluripotent cell lines that were generated under the Human Induced Pluripotent Stem Cell Initiative funded by a grant from the Wellcome Trust and Medical Research Council, supported by the Wellcome Trust (WT098051) and the NIHR/Wellcome Trust Clinical Research Facility, and acknowledges Life Science Technologies Corporation as the provider of Cytotune (HipSci.org). The Cardiovascular Epidemiology Unit is supported by core funding from the UK Medical Research Council (MR/L003120/1), the British Heart Foundation (RG/13/13/30194; RG/18/13/33946) and the National Institute for Health Research [Cambridge Biomedical Research Centre at the Cambridge University Hospital’s NHS Foundation Trust]. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care
Subwavelength grating metamaterial waveguides and ring resonators on a silicon nitride platform
We propose and demonstrate subwavelength grating (SWG) metamaterial
waveguides and ring resonators on a silicon nitride platform for the first
time. The SWG waveguide is engineered such that a large overlap of 53% of the
Bloch mode with the top cladding material is achieved, demonstrating excellent
potential for applications in evanescent field sensing and light amplification.
The devices, which have critical dimensions greater than 100 nm, are fabricated
using a commercial rapid turn-around silicon nitride prototyping foundry
process using electron beam lithography. Experimental characterization of the
fabricated device reveals excellent ring resonator internal quality factor
(2.11x10^5) and low propagation loss (~1.5 dB/cm) in the C-band, a significant
improvement of both parameters compared to silicon based SWG ring resonators.
These results demonstrate the promising prospects of SWG metamaterial
structures for silicon nitride based photonic integrated circuits.Comment: 12 pages, 7 figures, submitted to Laser & Photonics Reviews for
publicatio
“Acting the part of an illiterate savage”: James Kelman and the question of postcolonial masculinity
Distinct p53 acetylation cassettes differentially influence gene-expression patterns and cell fate
The activity of the p53 gene product is regulated by a plethora of posttranslational modifications. An open question is whether such posttranslational changes act redundantly or dependently upon one another. We show that a functional interference between specific acetylated and phosphorylated residues of p53 influences cell fate. Acetylation of lysine 320 (K320) prevents phosphorylation of crucial serines in the NH2-terminal region of p53; only allows activation of genes containing high-affinity p53 binding sites, such as p21/WAF; and promotes cell survival after DNA damage. In contrast, acetylation of K373 leads to hyperphosphorylation of p53 NH2-terminal residues and enhances the interaction with promoters for which p53 possesses low DNA binding affinity, such as those contained in proapoptotic genes, leading to cell death. Further, acetylation of each of these two lysine clusters differentially regulates the interaction of p53 with coactivators and corepressors and produces distinct gene-expression profiles. By analogy with the “histone code” hypothesis, we propose that the multiple biological activities of p53 are orchestrated and deciphered by different “p53 cassettes,” each containing combination patterns of posttranslational modifications and protein–protein interactions
Association between rheumatoid arthritis disease activity, progression of functional limitation and long-term risk of orthopaedic surgery : Combined analysis of two prospective cohorts supports EULAR treat to target DAS thresholds
Objectives: To examine the association between disease activity in early rheumatoid arthritis (RA), functional limitation and long-term orthopaedic episodes. Methods: Health Assessment Questionnaire (HAQ) disability scores were collected from two longitudinal early RA inception cohorts in routine care; Early Rheumatoid Arthritis Study and Early Rheumatoid Arthritis Network from 1986 to 2012. The incidence of major and intermediate orthopaedic surgical episodes over 25 years was collected from national data sets. Disease activity was categorised by mean disease activity score (DAS28) annually between years 1 and 5; remission (RDAS≤2.6), low (LDAS>2.6-3.2), low-moderate (LMDAS≥3.2-4.19), high-moderate (HMDAS 4.2-5.1) and high (HDAS>5.1). Results: Data from 2045 patients were analysed. Patients in RDAS showed no HAQ progression over 5 years, whereas there was a significant relationship between rising DAS28 category and HAQ at 1 year, and the rate of HAQ progression between years 1 and 5. During 27 986 person-years follow-up, 392 intermediate and 591 major surgeries were observed. Compared with the RDAS category, there was a significantly increased cumulative incidence of intermediate surgery in HDAS (OR 2.59 CI 1.49 to 4.52) and HMDAS (OR 1.8 CI 1.05 to 3.11) categories, and for major surgery in HDAS (OR 2.48 CI 1.5 to 4.11), HMDAS (OR 2.16 CI 1.32 to 3.52) and LMDAS (OR 2.07 CI 1.28 to 3.33) categories. There was no significant difference in HAQ progression or orthopaedic episodes between RDAS and LDAS categories. Conclusions: There is an association between disease activity and both poor function and long-term orthopaedic episodes. This illustrates the far from benign consequences of persistent moderate disease activity, and supports European League Against Rheumatism treat to target recommendations to secure low disease activity or remission in all patients.Peer reviewedFinal Published versio
Heuristic and Hierarchical-Based Population Mining of Salmonella enterica Lineage I Pan-Genomes as a Platform to Enhance Food Safety
The recent incorporation of bacterial whole-genome sequencing (WGS) into Public Health laboratories has enhanced foodborne outbreak detection and source attribution. As a result, large volumes of publicly available datasets can be used to study the biology of foodborne pathogen populations at an unprecedented scale. To demonstrate the application of a heuristic and agnostic hierarchical population structure guided pan-genome enrichment analysis (PANGEA), we used populations of S. enterica lineage I to achieve two main objectives: (i) show how hierarchical population inquiry at different scales of resolution can enhance ecological and epidemiological inquiries; and (ii) identify population-specific inferable traits that could provide selective advantages in food production environments. Publicly available WGS data were obtained from NCBI database for three serovars of Salmonella enterica subsp. enterica lineage I (S. Typhimurium, S. Newport, and S. Infantis). Using the hierarchical genotypic classifications (Serovar, BAPS1, ST, cgMLST), datasets from each of the three serovars showed varying degrees of clonal structuring. When the accessory genome (PANGEA) was mapped onto these hierarchical structures, accessory loci could be linked with specific genotypes. A large heavy-metal resistance mobile element was found in the Monophasic ST34 lineage of S. Typhimurium, and laboratory testing showed that Monophasic isolates have on average a higher degree of copper resistance than the Biphasic ones. In S. Newport, an extra sugEgene copy was found among most isolates of the ST45 lineage, and laboratory testing of multiple isolates confirmed that isolates of S. Newport ST45 were on average less sensitive to the disinfectant cetylpyridimium chloride than non-ST45 isolates. Lastly, data-mining of the accessory genomic content of S. Infantis revealed two cryptic Ecotypes with distinct accessory genomic content and distinct ecological patterns. Poultry appears to be themajor reservoir for Ecotype 1, and temporal analysis further suggested a recent ecological succession, with Ecotype 2 apparently being displaced by Ecotype 1. Altogether, the use of a heuristic hierarchical-based population structure analysis that includes bacterial pan-genomes (core and accessory genomes) can (1) improve genomic resolution for mapping populations and accessing epidemiological patterns; and (2) define lineage-specific informative loci that may be associated with survival in the food chain
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