Altered cord blood biomarkers in neonatal brain injury

Introduction: Alterations in RNA and proteins observed at birth may have long-term effects on early life. Perinatal asphyxia (PA) accounts for a quarter of all global neonatal deaths. Early intervention is critical for developing strategies to improve long-term outcome. Early identifiers for infants at risk of HIE is prone to subjective-bias or poorly objective biochemical measurements. The umbilical cord blood (UCB) can give a snapshot of both the newborn and the in-utero environment. It is non-invasive to both mother and infant and contains microRNA (miRNA), messenger RNA (mRNA) and circulating proteins that can exist stably in the circulation. This thesis aims to progress further the knowledge of UCB biomarkers using low-throughput techniques in both RNA and protein analyses, and to explore and validate proposed and potential biomarkers in HIE. Methods: This thesis utilised three distinct, well-defined cohorts throughout, the BiHIVE1 cohort (2009- 2011), the BiHiVE2 cohort (2012-1015), and the BASELINE longitudinal birth cohort (2008- 2016). The BiHIVE1 cohort was recruited in Cork, Ireland (7500 live births per annum), this study included full-term infants with PA enrolled at birth. This cohort recruited 112 cases (40 developed HIE - 24 mild, 6 moderate and 10 severe), of these 52 had neurodevelopmental follow-up, and 7 died in infancy. For this cohort, healthy controls were recruited from the BASELINE cohort. The BiHiVE2 validation cohort was recruited in Cork, Ireland and Karolinska Huddinge, Sweden (4400 live births per annum), this study included infants with PA along with healthy control infants. This cohort recruited 353 cases (48 developed HIE - 32 mild, 14 moderate and 2 severe) and 289 controls, 449 had neurodevelopmental follow-up, and no deaths occurred in infancy. Infants with perinatal asphyxia had matched inclusion criteria across both BiHiVE1 and BiHiVE2. Infants were assigned a modified Sarnat score at 24 hours and were followed-up with neurological assessment and neurodevelopmental outcome at 18-36 months of age. Umbilical cord serum, plasma and whole blood were processed and biobanked across all cohorts at delivery and stored at -80°C. Techniques employed throughout the thesis include blood processing, RNA isolations of whole blood miRNA and mRNA, and subsequent cDNA synthesis and quantitative real-time polymerase chain reaction (qPCR). Protein expression measurements were conducted with sandwich enzyme-linked immunosorbent assays (ELISA) on cord serum samples. All statistical analyses were conducted using IBM SPSS Statistics 24, graphical representation of data was generated using GraphPad Prism 8. Results: miRNA Panel: One-hundred and sixty infants had miRNA qPCR analyses across both BiHiVE1 and BiHiVE2. In BiHIVE1, 12 candidate miRNAs were identified, and 7 of these miRNAs were chosen for validation in BiHIVE2. The BiHIVE2 cohort showed consistent alteration of 3 miRNAs; miR-374a-5p was decreased in infants diagnosed as having HIE compared with healthy control infants (P = 0.009), miR-376c-3p was decreased in infants with PA compared with healthy control infants (P = 0.004), and miR-181b-5p was decreased in infants eligible for therapeutic hypothermia (TH) (P = 0.02). Predicted mRNA Targets: One-hundred and twenty-six infants had mRNA analyses. In the grade of HIE severity, the level of mFZD4 was increased in severe HIE vs mild HIE (P = 0.004), and severe HIE vs moderate HIE (P = 0.003). Fifty-six infants were included in the neurodevelopmental outcome analysis; Levels of mNFAT5 were increased in severely abnormal vs normal outcome (P = 0.036), and in severely abnormal vs mildly abnormal outcome (P = 0.013). Levels of mFZD4 were increased in severely abnormal vs normal outcome (P = 0.004), and in severely abnormal vs mildly abnormal outcome (P = 0.026). Interleukin-16: One-hundred and thirteen infants were included in the final analyses. Cord blood-based IL-16 was increased in infants with perinatal asphyxia and HIE relative to controls (P = 0.025). IL-16 was also increased in the HIE group relative to controls (P = 0.042). There was no significant difference in IL-16 across grades of HIE or in those with abnormal outcomes at 2-years of age. Activin A and mACVR2B: Serum activin A analyses included 101 infants. No differences were observed across the groups (P = 0.693). The HIE group included 23 infants; a combination of mild and moderate HIE, without infants with a severe grade. No differences were observed across the grades of HIE (P = 0.115). Whole blood mACVR2B analyses included 68 infants, and no differences were observed across the groups (P = 0.746). The HIE group included 22 infants, and no differences were observed across the grades of HIE (mild and moderate only) (P = 0.468). No differences were observed in infants followed up to 18-36 months in serum activin A or in whole blood mACVR2B, (P = 0.550) and (P = 0.881) respectively. Conclusions: This thesis has identified and validated the decreased expression of UCB miRNA (miR-181b, 374a and miR-376c), increased expression of UCB mRNA (mNFAT5 and mFZD4) and increased UCB cytokine expression (IL-16) across two cohorts in HIE. It validates previous miRNA whole blood biomarkers of PA (miR-376c) and HIE (miR-374a) and proposes novel whole blood mRNA biomarkers as assessors for both HIE severity (mFZD4) and long-term neurodevelopmental outcome (mNFAT5 and mFZD4), which can outperform current measurements. These miRNA and mRNA could aid current measures as objective diagnostic and prognostic markers of HIE. It has further explored the strengths of cytokines and proteins and confirmed their inability as biomarkers across HIE groups and grades. This work has an important role in further developing UCB-based biomarkers in early life

The market for non-executive directors: Does acquisition performance influence future board seats?

This paper investigates whether non-executive directors associated with good (bad) board decisions are subsequently rewarded (penalized) in the market for directors. This question is addressed by assessing whether the post-acquisition performance of acquiring companies influences the number of non-executive directorships that non-executives involved in these acquisitions hold subsequent to the acquisition. We find that non-executives on the boards of acquirers that increase (omit or cut) their dividend subsequently hold more (fewer) non-executive directorships in listed companies. Our findings suggest that the non-executive labor market is efficient and rewards (penalizes) non-executives for good (bad) acquisitions

Endogeneity: how failure to correct for it can cause wrong inferences and some remedies

Although researchers in business and management are becoming increasingly aware of the importance of endogeneity affecting regression analysis, they frequently do not have the right methodological toolkit to adjust for this issue. This paper discusses such a toolkit. There are also areas in business and management research which to date seem to be mostly oblivious about the endogeneity issue. This paper highlights such an area, which studies the question as to whether firms that are cross-listed on a foreign stock exchange are charged premium fees by their auditors. When the same methodology (pooled ordinary least squares) as in the existing literature is used, the existence of an audit fee premium for cross-listed firms seems to be confirmed. However, once methodologies are used which adjust for the various types of endogeneity (i.e. omitted variable bias, simultaneous and dynamic endogeneity) there is no longer support for the existence of such a generalised premium. Hence, this paper not only illustrates that failure to adjust for endogeneity has severe consequences such as drawing the wrong inferences, but it also reviews various ways to control for the different types of endogeneity

Sovereign wealth funds, productivity and people: The impact of Norwegian government pension fund - global investments in the UK

Sovereign Wealth Funds (SWFs) have an increasing presence in the global financial ecosystem, principally through their investments in equities, which, in turn, may influence HRM. This study examines the influence of the world’s largest SWF, the Norwegian Government Pension Fund-Global (NGPF-G), on employment in its UK investee firms. We find that firms with NGPF-G investment are significantly less likely to reduce their demand for labour, more specifically in the immediate aftermath of the 2008 financial crisis. When a drop in the demand for labour does occur, it is less extreme when compared to similar organizations without a NGPF-G shareholding, and this is evident even in the case of relatively small NGPF-G investments. These findings are in line with the fund’s objective of promoting corporate sustainability and Norwegian values. We draw out the key implications of our findings for HR practice

Endogeneity: how failure to correct for it can cause wrong inferences and some remedies

Although researchers in business and management are becoming increasingly aware of the importance of endogeneity affecting regression analysis, they frequently do not have the right methodological toolkit to adjust for this issue. In this paper we discuss such a toolkit. There are also areas in business and management research which to date seem to be mostly oblivious about the endogeneity issue. We highlight such an area, which studies the question of whether firms that are cross-listed on a foreign stock exchange are charged premium fees by their auditors. When the same methodology (pooled ordinary least squares) as in the existing literature is used, the existence of an audit fee premium for cross-listed firms seems to be confirmed. However, once methodologies are used which adjust for the various types of endogeneity (i.e. omitted variable bias, simultaneous and dynamic endogeneity) there is no longer support for the existence of such a generalized premium. Hence, not only do we illustrate that failure to adjust for endogeneity has severe consequences such as drawing the wrong inferences, but we also review various ways to control for the different types of endogeneity

Early Scottish Monasteries and Prehistory: A Preliminary Dialogue

Reflecting oil the diversity of monastic attributes found in the east and west of Britain, the author proposes that prehistoric ritual practice was influential on monastic form. An argument is advanced that this was not based solely oil inspiration Front the landscape, nor oil conservative tradition, but oil the intellectual reconciliation of Christian and non-Christian ideas, with disparate results that account. for the differences in monumentality. Among more general matters tentatively credited with a prehistoric root are the cult of relics, the tonsure and the date of Easter

Synthesis and evaluation of aromatic BDSF bioisosteres on biofilm formation and colistin sensitivity in pathogenic bacteria

The diffusible signal factor family (DSF) of molecules play an important role in regulating intercellular communication, or quorum sensing, in several disease-causing bacteria. These messenger molecules, which are comprised of cis-unsaturated fatty acids, are involved in the regulation of biofilm formation, antibiotic tolerance, virulence and the control of bacterial resistance. We have previously demonstrated how olefinic N-acyl sulfonamide bioisosteric analogues of diffusible signal factor can reduce biofilm formation or enhance antibiotic sensitivity in a number of bacterial strains. This work describes the design and synthesis of a second generation of aromatic N-acyl sulfonamide bioisosteres. The impact of these compounds on biofilm production in Acinetobacter baumannii, Escherichia coli, Burkholderia multivorans, Burkholderia cepacia, Burkholderia cenocepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia is evaluated, in addition to their effects on antibiotic tolerance. The ability of these molecules to increase survival rates on co-administration with colistin is also investigated using the Galleria infection model

Parent-led massage and sleep EEG for term-born infants: A randomized controlled parallel-group study

AIM: To examine the impact of parent-led massage on the sleep electroencephalogram (EEG) features of typically developing term-born infants at 4 months. METHOD: Infants recruited at birth were randomized to intervention (routine parent-led massage) and control groups. Infants had a daytime sleep EEG at 4 months and were assessed using the Griffiths Scales of Child Development, Third Edition at 4 and 18 months. Comparative analysis between groups and subgroup analysis between regularly massaged and never-massaged infants were performed. Groups were compared for sleep stage, sleep spindles, quantitative EEG (primary analysis), and Griffiths using the Mann-Whitney U test. RESULTS: In total, 179 out of 182 infants (intervention: 83 out of 84; control: 96 out of 98) had a normal sleep EEG. Median (interquartile range) sleep duration was 49.8 minutes (39.1-71.4) (n = 156). A complete first sleep cycle was seen in 67 out of 83 (81%) and 72 out of 96 (75%) in the intervention and control groups respectively. Groups did not differ in sleep stage durations, latencies to sleep and to rapid eye movement sleep. Sleep spindle spectral power was greater in the intervention group in main and subgroup analyses. The intervention group showed greater EEG magnitudes, and lower interhemispherical coherence on subgroup analyses. Griffiths assessments at 4 months (n = 179) and 18 months (n = 173) showed no group differences in the main and subgroup analyses. INTERPRETATION: Routine massage is associated with distinct functional brain changes at 4 months