1. Variability and sex-dependence of hypothermic neuroprotection in a rat model of neonatal hypoxic–ischaemic brain injury: a single laboratory meta-analysis
- Author
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Lars Walløe, Thomas R. Wood, Mari Falck, Marianne Thoresen, Damjan Osredkar, Hemmen Sabir, Else Marit Løberg, Julia Kristine Gundersen, and Elke Maes
- Subjects
0301 basic medicine ,Litter (animal) ,Male ,Science ,Encephalopathy ,Neuropathology ,Brain injuries ,Paediatric research ,Neuroprotection ,Article ,03 medical and health sciences ,0302 clinical medicine ,Sex Factors ,Meta-Analysis as Topic ,Hypothermia, Induced ,medicine ,Distribution (pharmacology) ,Animals ,Rats, Wistar ,Multidisciplinary ,business.industry ,Hypothermia ,medicine.disease ,Rats ,Clinical trial ,Disease Models, Animal ,030104 developmental biology ,Neuroprotective Agents ,Animals, Newborn ,Preclinical research ,Anesthesia ,Meta-analysis ,Hypoxia-Ischemia, Brain ,Diseases of the nervous system ,Medicine ,Female ,medicine.symptom ,business ,Laboratories ,030217 neurology & neurosurgery - Abstract
Therapeutic hypothermia (HT) is standard care for term infants with hypoxic–ischaemic (HI) encephalopathy. However, the efficacy of HT in preclinical models, such as the Vannucci model of unilateral HI in the newborn rat, is often greater than that reported from clinical trials. Here, we report a meta-analysis of data from every experiment in a single laboratory, including pilot data, examining the effect of HT in the Vannucci model. Across 21 experiments using 106 litters, median (95% CI) hemispheric area loss was 50.1% (46.0–51.9%; n = 305) in the normothermia group, and 41.3% (35.1–44.9%; n = 317) in the HT group, with a bimodal injury distribution. Median neuroprotection by HT was 17.6% (6.8–28.3%), including in severe injury, but was highly-variable across experiments. Neuroprotection was significant in females (p p = 0.07). Animals representing the median injury in each group within each litter (n = 277, 44.5%) were also analysed using formal neuropathology, which showed neuroprotection by HT throughout the brain, particularly in females. Our results suggest an inherent variability and sex-dependence of the neuroprotective response to HT, with the majority of studies in the Vannucci model vastly underpowered to detect true treatment effects due to the distribution of injury.
- Published
- 2020
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