The Composition of Human Milk and Infant Faecal Microbiota Over the First Three Months of Life: A Pilot Study

peer-reviewedHuman milk contains a diverse array of bioactives and is also a source of bacteria for the developing infant gut. The aim of this study was to characterize the bacterial communities in human milk and infant faeces over the first 3 months of life, in 10 mother-infant pairs. The presence of viable Bifidobacterium and Lactobacillus in human milk was also evaluated. MiSeq sequencing revealed a large diversity of the human milk microbiota, identifying over 207 bacterial genera in milk samples. The phyla Proteobacteria and Firmicutes and the genera Pseudomonas, Staphylococcus and Streptococcus were the predominant bacterial groups. A core of 12 genera represented 81% of the microbiota relative abundance in milk samples at week 1, 3 and 6, decreasing to 73% at week 12. Genera shared between infant faeces and human milk samples accounted for 70–88% of the total relative abundance in infant faecal samples, supporting the hypothesis of vertical transfer of bacteria from milk to the infant gut. In addition, identical strains of Bifidobacterium breve and Lactobacillus plantarum were isolated from the milk and faeces of one mother-infant pair. Vertical transfer of bacteria via breastfeeding may contribute to the initial establishment of the microbiota in the developing infant intestine

Development and validation of an LC-MS/MS assay for the quantification of efavirenz in different biological matrices

Aim: The non-nucleoside reverse transcriptase inhibitor efavirenz is one of the most prescribed antiretroviral therapeutics. Efavirenz-containing therapy has become associated with the occurrence of CNS side effects, including sleep disturbances, depression and even psychosis. Results: The investigation of efavirenz distribution required the development of a versatile and sensitive method. In addition to plasma, quantification was required in brain tissue and phosphate-buffered saline. The assay presented here was linear from 1.9 to 500 ng/ml. Accuracy and precision ranged between 93.7 and 99.5%, and 1.5 and 5.6%, respectively. Discussion: The method developed here represents a versatile, sensitive and easy-to-use assay. The assay has been applied to in vitro and in vivo samples demonstrating reliable efavirenz quantification in multiple matrices

Understanding disposition of efavirenz and application in solid drug nanoparticle development

Efavirenz displays many desirable pharmacokinetic properties such as a long half-life allowing once daily dosing and potency against HIV. Despite these favourable properties efavirenz-containing therapy is associated with the development of central nervous system (CNS) toxicities. Current investigations indicate that high plasma concentrations of efavirenz play a putative role in the development of CNS side effects, but there is a current paucity of data relating to the underlying mechanisms of toxicity. Various nanotechnologies have been explored in attempts to mitigate some of the limitations with efavirenz. While there has been progress in increasing the bioavailability of efavirenz there has been no attempt to assess the impact of increased exposure to efavirenz on CNS toxicity. The body of work presented in this thesis aimed firstly to investigate the underlying mechanism of efavirenz CNS toxicity and secondly to assess uptake and CNS toxicity of efavirenz and a novel solid drug nanoformulation (SDN) of efavirenz. The work presented in this thesis utilised a variety of in vitro, in vivo and in silico methodologies. Chapter 2 utilised allelic discrimination polymerase chain reaction in order to investigate the association of single nucleotide polymorphism (SNPs) in the gamma aminobutyric acid receptor with early treatment discontinuation of efavirenz. In order to assess the effects of SDN efavirenz on the occurrence of CNS toxicities, an in vivo model of anxiety (elevated plus maze) was employed (chapter 3). Chapter 4 detailed the development of a robust and sensitive liquid chromatography tandem mass spectrometer assay for the detection of efavirenz in multiple matrices. The uptake of efavirenz and SDN efavirenz in the CNS was investigated utilising cellular uptake and inhibition studies (chapter 5). Physiologically based pharmacokinetic (PBPK) simulations were used to investigate the distribution of efavirenz in plasma, cerebrospinal fluid (CSF) and brain tissue (chapter 6). Despite an initial trend with Rs211014 and Rs6556547 (univariate analysis) of the training cohort, these SNPs were not found to be significant in the multivariate analysis or in either analysis of the test cohort. Following multiple doses rats treated with efavirenz, but not SDN efavirenz, exhibited anxiety-like behaviour in the EPM. The profile of changes indicated some clear behavioural effects that are likely to be linked to drug-related CNS effects. In particular, a tendency of efavirenz to increase time spent on the central platform may be indicative of anxiogenesis. Cellular accumulation of efavirenz was reduced significantly by montelukast and amantadine, with the reduction in accumulation by prazosin bordering on significance (indicating efavirenz may be a substrate for OCT1 and an SLCO transporter). Additionally, cellular accumulation of SDN efavirenz particles was reduced by dynasore, indicating dynamin-mediated uptake. PBPK simulations predicted efavirenz accumulation in brain tissue, with a tissue to plasma ratio 15.8. The natural occurrence of conditions such as depression involves a complex interplay of factors influencing neurotransmission. This makes identifying single predictors of efavirenz CNS toxicity more difficult. The data presented in this thesis may be built upon to understand the mechanisms governing efavirenz disposition in the CNS and factors influencing the occurrence of CNS toxicity

“YOU MUST HAVE YOUR WEBCAM ON FOR THE ENTIRE DURATION OF THE EXAMINATION”: THE TRADE-OFF BETWEEN THE INTEGRITY OF ON-LINE ASSESSMENTS AND THE PRIVACY RIGHTS OF STUDENTS

The impact of COVID-19 has been widespread and far-reaching, and one domain that has experienced severe disruption is the university education sector, where the entire apparatus of teaching and assessment for many programmes of study had to move on-line in a matter of days. This was accomplished notably through enormous co-operation between staff and students in educational institutions (Adnan and Anwar, 2020). The negative economic impacts of COVID-19 on university students has been highlighted in terms of poor access to online resources, delayed graduation and lost internships with this effect felt more keenly by students from low socioeconomic backgrounds (Aucejo, 2020). However, an issue that has been less reported is how the crisis highlighted mismatches between on the one hand the regulations and requirements of the educational institutions, and on the other hand the privacy rights (and needs) of the students. In this research we are investigating the challenges associated with the potential for students and teachers to inadvertently share aspects of their private lives as part of on-line teaching and assessment, as well as the ethical challenges of monitoring students during exams. Some educational institutes have used software for monitoring students during assessments (called e-Proctoring systems), and these systems lead to a range of potential ethical concerns, particularly if the systems employ facial recognition systems and/or artificial intelligence systems to detect potential malfeasance. One voice that hasn’t been included in this discussion heretofore is the student voice, so this research includes the design and development of the WebCam Usage Student Survey (WUSS), and a group of computer science students (N=44) were asked for their opinions on a wide range of privacy issues (as these student have some idea on the potential pitfalls of using theses types of technologies). Their views are varied and nuanced, and their perspective in combination with the literature will be used to develop a series of guidelines for both general webcam usage, as well as for the use of e-Proctoring systems. This issue is one of a rapidly growing number of computer ethics issues that have been emerging recently, to such an extent that a number of third-level institutes across Europe are collaborating to explore some of these key ethical challenges, and to develop educational content that is both based on pedagogically sound principles, and motivated by international exemplars of best practice to highlight these matters as part of the Erasmus+ Ethics4EU project (O’Sullivan and Gordon, 2020)

Ethics4eu: Designing New Curricula For Computer Science Ethics Education: Case Studies For Ai Ethics

The computing ethics landscape is changing rapidly, as new technologies become more complex and pervasive, and people choose to interact with them in new and distinct ways. The resultant interactions are more novel and less easy to categorise using traditional ethical frameworks. It is important that developers of these technologies do not live in an ethical vacuum, that they think about the consequences of their creations, and take measures to prevent others being harmed by their work. To equip developers to rise to this challenge and create a positive future for the use of technology, it important that ethics becomes a central element of computer science education. To this end, the Ethics4EU project has developed curricula on a wide range of topics including privacy and agency of personal information, digital literacy, data governance and accountability, surveillance applications, algorithmic decision and automating human intelligence for robotics and autonomous vehicles. Crucially the content examines computing ethics, not only in terms of hardware and software, but how systems, people, organisations and society interact with technology.In this paper, we present our interdisciplinary approach to developing educational content for AI Ethics. This includes accessible teaching materials, in-class activities, sample assessments, practical guidelines and instructor guides. We discuss findings of an evaluation of the developed content with undergraduate computer science students

Fluorine negative ion density measurement in a dual frequency capacitive plasma etch reactor by cavity ring-down spectroscopy

F⁻ negative ions were detected by direct observation of the weak photodetachmentabsorption continuum below 364.5nm by cavity ring-down spectroscopy. The negative ions were generated in a modified industrial dielectricplasmaetch reactor, with 2+27MHz dual frequency capacitive excitation in Ar∕CF₄∕O₂ and Ar∕C₄F₈∕O₂ gas mixtures. The F⁻ signal was superimposed on an unidentified absorption continuum, which was diminished by O₂ addition. The F⁻ densities were in the range of (0.5–3)×10¹¹cm⁻³, and were not significantly different for single (27MHz) or dual (2+27MHz) frequency excitation, not confirming recent modeling predictions.The authors wish to thank Lam Research Corporation for donation of equipment and financial support

Increased telomere attrition following renal transplantation: impact of anti-metabolite therapy

Background: The uremic milieu exposes chronic kidney disease (CKD) patients to premature ageing processes. The impact of renal replacement therapy (dialysis and renal transplantation [RTx]) or immunosuppressive treatment regimens on ageing biomarkers has scarcely been studied. Methods: In this study telomere length in whole blood cells was measured in 49 dialysis patients and 47 RTx patients close to therapy initiation and again after 12 months. Forty-three non-CKD patients were included as controls. Results: Non-CKD patients had significantly (P <= 0.01) longer telomeres than CKD patients. Telomere attrition after 12 months was significantly greater in RTx patients compared to dialysis patients (P = 0.008). RTx patients receiving mycophenolate mofetil (MMF) had a greater (P = 0.007) degree of telomere attrition compared to those treated with azathioprine. After 12 months, folate was significantly higher in RTx patients than in dialysis patients (P < 0.0001), whereas the opposite was true for homocysteine (P < 0.0001). The azathioprine group had lower levels of folate after 12 months than the MMF group (P = 0.003). Conclusions: The associations between immunosuppressive therapy, telomere attrition, and changes in folate indicate a link between methyl donor potential, immunosuppressive drugs, and biological ageing. The hypothesis that the increased telomere attrition, observed in the MMF group after RTx, is driven by the immunosuppressive treatment, deserves further attention

Efavirenz Is Predicted To Accumulate in Brain Tissue: an In Silico, In Vitro, and In Vivo Investigation

Adequate concentrations of efavirenz in the central nervous system (CNS) are necessary to suppress viral replication, but high concentrations may increase the likelihood of CNS adverse drug reactions. The aim of this investigation was to evaluate the efavirenz distribution in the cerebrospinal fluid (CSF) and the brain by using a physiologically based pharmacokinetic (PBPK) simulation for comparison with rodent and human data. The efavirenz CNS distribution was calculated using a permeability-limited model on a virtual cohort of 100 patients receiving efavirenz (600 mg once daily). Simulation data were then compared with human data from the literature and with rodent data. Wistar rats were administered efavirenz (10 mg kg of body weight(−1)) once daily over 5 weeks. Plasma and brain tissue were collected for analysis via liquid chromatography-tandem mass spectrometry (LC-MS/MS). The median maximum concentrations of drug (C(max)) were predicted to be 3,184 ng ml(−1) (interquartile range [IQR], 2,219 to 4,851 ng ml(−1)), 49.9 ng ml(−1) (IQR, 36.6 to 69.7 ng ml(−1)), and 50,343 ng ml(−1) (IQR, 38,351 to 65,799 ng ml(−1)) in plasma, CSF, and brain tissue, respectively, giving a tissue-to-plasma ratio of 15.8. Following 5 weeks of oral dosing of efavirenz (10 mg kg(−1)), the median plasma and brain tissue concentrations in rats were 69.7 ng ml(−1) (IQR, 44.9 to 130.6 ng ml(−1)) and 702.9 ng ml(−1) (IQR, 475.5 to 1,018.0 ng ml(−1)), respectively, and the median tissue-to-plasma ratio was 9.5 (IQR, 7.0 to 10.9). Although it is useful, measurement of CSF concentrations may give an underestimation of the penetration of antiretrovirals into the brain. The limitations associated with obtaining tissue biopsy specimens and paired plasma and CSF samples from patients make PBPK modeling an attractive tool for probing drug distribution