Perinatal asphyxia: current status and approaches towards neuroprotective strategies, with focus on sentinel proteins

Delivery is a stressful and risky event menacing the newborn. The mother-dependent respiration has to be replaced by autonomous pulmonary breathing immediately after delivery. If delayed, it may lead to deficient oxygen supply compromising survival and development of the central nervous system. Lack of oxygen availability gives rise to depletion of NAD+ tissue stores, decrease of ATP formation, weakening of the electron transport pump and anaerobic metabolism and acidosis, leading necessarily to death if oxygenation is not promptly re-established. Re-oxygenation triggers a cascade of compensatory biochemical events to restore function, which may be accompanied by improper homeostasis and oxidative stress. Consequences may be incomplete recovery, or excess reactions that worsen the biological outcome by disturbed metabolism and/or imbalance produced by over-expression of alternative metabolic pathways. Perinatal asphyxia has been associated with severe neurological and psychiatric sequelae with delayed clinical onset. No specific treatments have yet been established. In the clinical setting, after resuscitation of an infant with birth asphyxia, the emphasis is on supportive therapy. Several interventions have been proposed to attenuate secondary neuronal injuries elicited by asphyxia, including hypothermia. Although promising, the clinical efficacy of hypothermia has not been fully demonstrated. It is evident that new approaches are warranted. The purpose of this review is to discuss the concept of sentinel proteins as targets for neuroprotection. Several sentinel proteins have been described to protect the integrity of the genome (e.g. PARP-1; XRCC1; DNA ligase IIIα; DNA polymerase β, ERCC2, DNA-dependent protein kinases). They act by eliciting metabolic cascades leading to (i) activation of cell survival and neurotrophic pathways; (ii) early and delayed programmed cell death, and (iii) promotion of cell proliferation, differentiation, neuritogenesis and synaptogenesis. It is proposed that sentinel proteins can be used as markers for characterising long-term effects of perinatal asphyxia, and as targets for novel therapeutic development and innovative strategies for neonatal care

Consumer opinions on adverse events associated with medicines and vaccines

Parisa Aslani,1 Kim Hamrosi,1 Vivien Tong,1 Timothy F Chen,1 Jane Cook,2 Romano Fois,1 Theresa McGarry,3 Carter Moore,4 Rodney Peters,5 Sarah Spagnardi,6 Karen Whitelock7 1Faculty of Pharmacy, The University of Sydney, Camperdown, NSW, Australia; 2Therapeutic Goods Administration, Canberra, ACT, Australia; 3Celgene Pty Ltd., Southbank, VIC, Australia; 4Consumers Health Forum of Australia, Canberra, ACT, Australia; 5Pharmacovigilant Consultant, Sydney, NSW, Australia; 6NPS MedicineWise, Sydney, NSW, Australia; 7Novartis Pharmaceuticals Australia Pty Ltd., Sydney, NSW, Australia Introduction: Despite the availability of an Australian consumer adverse event (AE) reporting system for over 50 years, reporting rates remain low. A comprehensive understanding of consumer perceptions and experiences regarding AEs is needed to further ascertain factors impacting their engagement in AE reporting. Aim: The aim of this study was to explore consumer opinions about AEs potentially associated with medicines and vaccines, and their experiences and understanding of managing and reporting AEs. Methods: Six focus groups were conducted across metropolitan Sydney with a total of 48 adult participants. A semi-structured focus group topic guide was developed to explore consumers’ understanding, experiences, and actions taken in relation to AEs; and perspectives on managing treatment benefits and harms. Discussions were audio-recorded with participant permission and transcribed verbatim. Transcripts were thematically analyzed. Results: Consumers acknowledged the potential for side effects (SEs), however inaccurately estimated SE risk in response to verbal descriptors such as “common.” Consumer appraisal of treatment benefits and harms was influenced by factors such as medical condition(s), previous experiences, and beliefs. Although many had experienced SEs, consumers only reported them if considered severe or troublesome. Minimal awareness of consumer AE reporting systems was evident. Doctors were the primary avenue for reporting; consumers preferred doctors to act as the intermediary in reporting AEs to an independent body. Conclusion: Consumers’ lack of awareness of AE reporting systems was evident. With the complexities inherent in benefit/harm risk appraisal, information seeking, and AE reporting preferences, better consumer understanding of AEs and the systems available for reporting is needed. Keywords: patient, reporting, side effects, qualitative, focus groups, drugs, vaccine

Unique functional properties of somatostatin-expressing GABAergic neurons in mouse barrel cortex

Neocortical GABAergic neurons have diverse molecular, structural and electrophysiological features, but the functional correlates of this diversity are largely unknown. We found unique membrane potential dynamics of somatostatin-expressing (SOM) neurons in layer 2/3 of the primary somatosensory barrel cortex of awake behaving mice. SOM neurons were spontaneously active during periods of quiet wakefulness. However, SOM neurons hyperpolarized and reduced action potential firing in response to both passive and active whisker sensing, in contrast with all other recorded types of nearby neurons, which were excited by sensory input. Optogenetic inhibition of SOM neurons increased burst firing in nearby excitatory neurons. We hypothesize that the spontaneous activity of SOM neurons during quiet wakefulness provides a tonic inhibition to the distal dendrites of excitatory pyramidal neurons. Conversely, the inhibition of SOM cells during active cortical processing likely enhances distal dendritic excitability, which may be important for top-down computations and sensorimotor integration