Cholestasis-Induced Cognitive Decline: Neurological Mechanisms and Therapeutic Implications

Ph. D. ThesisCognitive dysfunction occurs during the cholestatic liver disease Primary biliary Cholangitis (PBC). Patients experience with short-term memory and concentration deficit, termed ‘brain fog’. This can be debilitating and severely affect quality of life, with no beneficial treatments (Newton, Hollingsworth et al. 2008) In this thesis, using the murine Bile Duct Ligation (BDL) model and in vitro modelling with human neuronal cells, I investigated the effects of cholestasis on the blood-brain barrier (BBB) and resultant changes within the brain. This study focussed on the hippocampus due to its crucial role in learning and memory. Changes to BBB could be observed from day 6, including astrocyte detachment, and permeability using MRI. By day 10 mice had visual spatial memory deficits, neuroinflammation was seen within the hippocampus, and changes were observed in gamma frequency oscillations. Interestingly, neurons in the hippocampus possessed features of senescence in cholestatic mice (telomere associated DNA damage, and P21+ RNA), highlighting parallels in pathology between the liver (where senescence is known to occur during cholestasis) and the brain. This effect was mirrored during in vitro studies, where neurons treated with PBC patient serum (to simulate pathological exposure to bile acids) also displayed increased sen-B-gal, a feature of senescence. In another strand, I examined the ability of both approved (ursodeoxycholic acid, Obeticholic Acid) and experimental (Bezafibrate) therapies to modify cognitive processes. Only Obeticholic Acid provides a potential therapeutic due to its in vivo and in vitro effects. Strikingly, OCA improve cognition and reduces neuronal senescence in BDL mice and in vitro when neurons are pre-treated before serum treatments. Therefore, the data presented in this thesis implicates senescence as a key pathological feature of cholestatic disease not just in the liver but also in brain where it has been previously linked to poor cognition (Baker, Wijshake et al. 2011, Fielder, Tweedy et al. 2020). Further investigation of early intervention with OCA may prove beneficial to patients experiencing cognitive deficit

The Development of a Measurement Tool Evaluating Knowledge Related to Sensory Processing among Graduate Occupational Therapy Students: A Process Description

With an increased demand arising from stake holders to provide more complex clinical experiences and to have students better prepared for clinical rotations, educators need to develop instructional tasks and measures to teach and assess clinical reasoning. The purpose of this article is to highlight a clinical simulation measure revolving around the A SECRET reasoning approach, which is also generalizable to other conditions and interventions. Preliminary findings of 1st year Master of Occupational Therapy students (n=8) who took part in a pilot of the A SECRET case scenario reported positive, yet not strong, attitudes toward the A SECRET assessment and the sensory processing related content delivered in an online format as a part of a larger study. Overall the student perceptions and the processes of the measure development suggest an inherent value of using the proposed type of simulated case scenarios in assisting occupational therapy students in their program’s first year with the development of clinical reasoning

First Year Occupational Therapy Students’ Clinical Reasoning Approach to Addressing Challenging Behaviors Related to Sensory Processing Using a Simulated Case Study

Occupational therapy students must be prepared to use clinical reasoning to select appropriate interventions for children with sensory processing disorders (SPDs). Although these interventions are typically taught in entry-level occupational therapy programs, there is little information regarding the method by which occupational therapy students are taught a clinical reasoning process to determine which sensory processing intervention to use with pediatric clients. A problem-solving framework called A SECRET was used to teach students clinical reasoning for children with SPDs, via an online, module-based course. Following the module, the students were tested with an online assessment tool regarding their ability to discriminate between appropriate and inappropriate intervention strategies, and to articulate their rationale to demonstrate how they clinically reasoned through a complex client case. Eight students participated in a focus group to provide their perceptions of the online delivery of the content and the A SECRET reasoning process. Five descriptive representations emerged from the qualitative data analysis: the A SECRET Process, Self-Regulation, the Occupational Therapy Practice Framework, Participation, and Safety/Security. The findings suggest an inherent value for online learning to assist occupational therapy students in their program’s first year to learn the A SECRET process and then clinically reason through a simulated case study

Clinical Outcome and Characterization of Local Field Potentials in Holmes Tremor Treated with Pallidal Deep Brain Stimulation

Background: Holmes tremor (HT) is an irregular, low-frequency rest tremor associated with prominent action and postural tremors. Currently, the most effective stereotactic target and neurophysiologic characterization of HT, specifically local field potentials (LFPs) are uncertain. We present the outcome, intraoperative neurophysiologic analysis with characterization of LFPs in a patient managed with left globus pallidus interna deep brain stimulation (Gpi DBS). Case Report: A 24-year-old male underwent left Gpi DBS for medically refractory HT. LFPs demonstrated highest powers in the delta range in Gpi. At the 6-month follow-up, a 90% reduction in tremor was observed. Discussion: Pallidal DBS should be considered as an alternative target for management of refractory HT. LFP demonstrated neuronal activity associated with higher power in the delta region, similarly seen in patients with generalized dystonia

Associations Between Covid-19-Related Threat, Stress, and Smoking in UK Adults Aged Under- and Over-30

It has been suggested that smoking and age are associated with higher vulnerability to Covid-19. While threat of Covid-19 may reduce or stop smoking, increased stress due to lockdown could increase smoking behaviour. This study aimed to investigate changes in smoking behaviour in relation to age, Covid-19-related threat and subjective perceived stress during the UK lockdown. A cross-sectional study was performed. Online adverts were used to recruit UK residents who smoked combustible tobacco any time from January 2020. A questionnaire measured demographic information, smoking behaviour pre- and during-lockdown, perceived subjective stress (PSS), and Covid-19 related threat. Data were collected from a total of 145 participants (58% women, 39% men, 3% non-binary; mean age: 26 years, SD = 7.7), during UK lockdown between 22nd May and 22nd June 2020. Independent of stress and Covid-19-related threat, smoking was reduced in those aged less than 30 years. In participants aged 30 and above, increases in smoking behaviour were associated with higher PSS. The results highlight the relevance of the different stages of life on the relationship between stress, threat, and smoking behaviour. Greater emphasis should be placed on stress reduction for adult smokers aged 30 and above to enable smoking cessation

A Systems Engineering Approach to Modeling and Analysis of Chronic Obstructive Pulmonary Disease (COPD)

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease characterized by airflow limitation. This study develops a systems engineering framework for representing important mechanistic details of COPD in a model of the cardio-respiratory system. In this model, we present the cardio-respiratory system as an integrated biological control system responsible for regulating breathing. Four engineering control system components are considered: sensor, controller, actuator, and the process itself. Knowledge of human anatomy and physiology is used to develop appropriate mechanistic mathematical models for each component. Following a systematic analysis of the computational model, we identify three physiological parameters associated with reproducing clinical manifestations of COPD - changes in the forced expiratory volume (FEV), lung volumes, and pulmonary hypertension. We quantify the changes in these parameters (airway resistance, lung elastance, and pulmonary resistance) as the ones that result in a systemic response that is diagnostic of COPD. A multivariate analysis reveals that the changes in airway resistance have a broad impact on the human cardio-respiratory system, and that the pulmonary circuit is stressed beyond normal under hypoxic environments in most COPD patients.Comment: 25 pages, 15 figure

Childhood Absence Epilepsy with Tonic-Clonic Seizures and Electroencephalogram 3–4-Hz Spike and Multispike–Slow Wave Complexes: Linkage to Chromosome 8q24

SummaryChildhood absence epilepsy (CAE), a common form of idiopathic generalized epilepsy, accounts for 5%–15% of childhood epilepsies. To map the chromosomal locus of persisting CAE, we studied the clinical and electroencephalographic traits of 78 members of a five-generation family from Bombay, India. The model-free affected–pedigree member method was used during initial screening with chromosome 6p, 8q, and 1p microsatellites, and only individuals with absence seizures and/or electroencephalogram 3–4-Hz spike– and multispike–slow wave complexes were considered to be affected. Significant P values of .00000–.02 for several markers on 8q were obtained. Two-point linkage analysis, assuming autosomal dominant inheritance with 50% penetrance, yielded a maximum LOD score (Zmax) of 3.6 for D8S502. No other locus in the genome achieved a significant Zmax. For five smaller multiplex families, summed Zmax was 2.4 for D8S537 and 1.7 for D8S1761. Haplotypes composed of the same 8q24 microsatellites segregated with affected members of the large family from India and with all five smaller families. Recombinations positioned the CAE gene in a 3.2-cM interval

Gender and Medieval archaeology: storming the castle

Despite feminist critiques over three decades, Archaeological scholarship remains predominantly focused on exploring patriarchal narratives and is thereby complicit in reinforcing structural inequalities. Questions must be asked of how the construction of archaeological knowledge affects representation and impacts on our ‘archaeologies’. This paper explores the relative absence of gendered approaches within Archaeology through the lens of Later Medieval Archaeology in particular, and with a micro-focus on Castle-studies in Britain and Ireland. Is there a reason for the silence in relation to gender in the archaeology of the later middle ages

Co-production of two whole-school sexual health interventions for English secondary schools: positive choices and project respect.

BACKGROUND: Whole-school interventions represent promising approaches to promoting adolescent sexual health, but they have not been rigorously trialled in the UK and it is unclear if such interventions are feasible for delivery in English secondary schools. The importance of involving intended beneficiaries, implementers and other key stakeholders in the co-production of such complex interventions prior to costly implementation and evaluation studies is widely recognised. However, practical accounts of such processes remain scarce. We report on co-production with specialist providers, students, school staff, and other practice and policy professionals of two new whole-school sexual heath interventions for implementation in English secondary schools. METHODS: Formative qualitative inquiry involving 75 students aged 13-15 and 23 school staff. A group of young people trained to advise on public health research were consulted on three occasions. Twenty-three practitioners and policy-makers shared their views at a stakeholder event. Detailed written summaries of workshops and events were prepared and key themes identified to inform the design of each intervention. RESULTS: Data confirmed acceptability of addressing unintended teenage pregnancy, sexual health and dating and relationships violence via multi-component whole-school interventions and of curriculum delivery by teachers (providing appropriate teacher selection). The need to enable flexibility for the timetabling of lessons and mode of parent communication; ensure content reflected the reality of young people's lives; and develop prescriptive teaching materials and robust school engagement strategies to reflect shrinking capacity for schools to implement public-health interventions were also highlighted and informed intervention refinements. Our research further points to some of the challenges and tensions involved in co-production where stakeholder capacity may be limited or their input may conflict with the logic of interventions or what is practicable within the constraints of a trial. CONCLUSIONS: Multi-component, whole-school approaches to addressing sexual health that involve teacher delivered curriculum may be feasible for implementation in English secondary schools. They must be adaptable to individual school settings; involve careful teacher selection; limit additional burden on staff; and accurately reflect the realities of young people's lives. Co-production can reduce research waste and may be particularly useful for developing complex interventions, like whole-school sexual health interventions, that must be adaptable to varying institutional contexts and address needs that change rapidly. When co-producing, potential limitations in relation to the representativeness of participants, the 'depth' of engagement necessary as well as the burden on participants and how they will be recompensed must be carefully considered. Having well-defined, transparent procedures for incorporating stakeholder input from the outset are also essential. Formal feasibility testing of both co-produced interventions in English secondary schools via cluster RCT is warranted. TRIAL REGISTRATION: Project Respect: ISRCTN12524938 . Positive Choices: ISRCTN65324176

Extracellular nanovesicles for packaging of CRISPR-Cas9 protein and sgRNA to induce therapeutic exon skipping

Prolonged expression of the CRISPR-Cas9 nuclease and gRNA from viral vectors may cause off-target mutagenesis and immunogenicity. Thus, a transient delivery system is needed for therapeutic genome editing applications. Here, we develop an extracellular nanovesicle-based ribonucleoprotein delivery system named NanoMEDIC by utilizing two distinct homing mechanisms. Chemical induced dimerization recruits Cas9 protein into extracellular nanovesicles, and then a viral RNA packaging signal and two self-cleaving riboswitches tether and release sgRNA into nanovesicles. We demonstrate efficient genome editing in various hard-to-transfect cell types, including human induced pluripotent stem (iPS) cells, neurons, and myoblasts. NanoMEDIC also achieves over 90% exon skipping efficiencies in skeletal muscle cells derived from Duchenne muscular dystrophy (DMD) patient iPS cells. Finally, single intramuscular injection of NanoMEDIC induces permanent genomic exon skipping in a luciferase reporter mouse and in mdx mice, indicating its utility for in vivo genome editing therapy of DMD and beyond