Readiness of Bystander Cardiopulmonary Resuscitation (BCPR) during the COVID-19 Pandemic: A Review

Early cardiopulmonary resuscitation (CPR) is a strong link in the of survival for sudden cardiac arrest. Hence, bystander CPR (BPCR) plays an important role in curbing mortality and morbidity from out-of-hospital sudden cardiac arrest. However, the recent global Coronavirus disease 2019 (COVID-19) pandemic has impacted both public training and confidence in performing out-of-hospital CPR. This paper reviews detailed information from databases including Google Scholar, Scopus, PubMed and Web of Science on the readiness of BCPR during the pandemic. We also discussed the challenges bystanders encountered during the COVID-19 pandemic and the precautions to follow. Finally, we also highlighted the limitations which would benefit future endeavours in establishing well-planned and sustainable CPR training programs for the public. Therefore, regardless of the existing COVID-19 pandemic, BCPR must be emphasised to curb out-of-hospital cardiac arrest (OHCA) mortality.

Simple Coordination and Cognitive Stimulation Activities for Cognitive Function Assessments using Functional Near-Infrared Spectroscopy

Functional near-infrared spectroscopy (fNIRS) is a non-invasive and high-density imaging device used for the evaluation of cognitive functions by measuring the oxygenated haemoglobin (HbO) and deoxygenated haemoglobin (HHb) levels in the prefrontal cortex. The present study determined the utilisation of fNIRS in detecting cerebral haemoglobin oxygenation level during coordination and simple cognitive stimulation activities in healthy young volunteers. Thirty subjects comprising equally of both genders were recruited. Subjects were tasked with coordination tests (plate tapping and block transfer tests) and cognitive stimulation activities (ruler drop test and MRAVLT) while the fNIRS system was attached to their prefrontal cortex area. The HbO and HHb levels were recorded and analysed using Repeated Measures ANOVA. The HbO levels during coordination tests differ significantly from resting state (p<0.05) in all but channel 2. All coordination tests elevated HbO levels compared to resting state except during block transfer test in channel 1. No significant difference was observed in HHb levels between coordination tests and resting state in all channels (p>0.05), except channel 3. All cognitive stimulation activities increased HbO levels compared to resting state; this change was significant in channels 3 and 4 (p<0.05). In contrast, HHb levels during all cognitive tests were lower compared to the resting state and was found to be significant in channels 2 and 3 (p<0.05). These findings suggested that coordination and cognitive stimulation activities activate prefrontal cortex in healthy young adults and could be potentially utilised as a valid screening tool for cognitive function assessments via fNIRS.

Neuroprotection Against NMDA-Induced Retinal Damage by Philanthotoxin-343 Involves Reduced Nitrosative Stress

N-methyl-D-aspartate receptor (NMDAR) overstimulation is known to mediate neurodegeneration, and hence represents a relevant therapeutic target for neurodegenerative disorders including glaucoma. This study examined the neuroprotective effects of philanthotoxin (PhTX)-343 against NMDA-induced retinal injury in rats. Male Sprague Dawley rats were divided into three groups; group 1 received phosphate buffer saline as the negative control, group 2 was injected with NMDA (160 nM) to induce retinal excitotoxic injury, and group 3 was pre-treated with PhTX-343 (160 nM) 24 h before NMDA exposure. All treatments were given intravitreally and bilaterally. Seven days post-treatment, rats were subjected to visual behaviour assessments using open field and colour recognition tests. Rats were then euthanized, and the retinas were harvested and subjected to haematoxylin and eosin (H&E) staining for morphometric analysis and 3-nitrotyrosine (3-NT) ELISA protocol as the nitrosative stress biomarker. PhTX-343 treatment prior to NMDA exposure improved the ability of rats to recognize visual cues and preserved visual functions (i.e., recognition of objects with different colours). Morphological examination of retinal tissues showed that the fractional ganglion cell layer thickness within the inner retina (IR) in the PhTX-343 treated group was greater by 1.28-fold as compared to NMDA-treated rats (p < 0.05) and was comparable to control rats (p > 0.05). Additionally, the number of retinal cell nuclei/100 μm² in IR for the PhTX-343-treated group was greater by 1.82-fold compared to NMDA-treated rats (p < 0.05) and was comparable to control group (p > 0.05). PhTX-343 also reduced the retinal 3-NT levels by 1.74-fold compared to NMDA-treated rats (p < 0.05). In conclusion, PhTX-343 pretreatment protects against NMDA-induced retinal morphological changes and visual impairment by suppressing nitrosative stress as reflected by the reduced retinal 3-NT level.

Philanthotoxin-343 attenuates retinal and optic nerve injury, and protects visual function in rats with N-methyl-D-aspartate-induced excitotoxicity

Retinal ganglion cell (RGC) loss and optic neuropathy, both hallmarks of glaucoma, have been shown to involve N-methyl-D-aspartate receptor (NMDAR)-mediated excitotoxicity. This study investigated the neuroprotective effects of Philanthotoxin (PhTX)-343 in NMDA-induced retinal injury to alleviate ensuing visual impairments. Sprague-Dawley rats were divided into three; Group I was intravitreally injected with phosphate buffer saline as the control, Group II was injected with NMDA (160 nM) to induce retinal excitotoxic injury, while Group III was injected with PhTX-343 (160 nM) 24 h prior to excitotoxicity induction with NMDA. Rats were subjected to visual behaviour tests seven days post-treatment and subsequently euthanized. Rat retinas and optic nerves were subjected to H&E and toluidine blue staining, respectively. Histological assessments showed that NMDA exposure resulted in significant loss of retinal cell nuclei and thinning of ganglion cell layer (GCL). PhTX-343 pre-treatment prevented NMDA-induced changes where the RGC layer morphology is similar to the control. The numbers of nuclei in the NMDA group were markedly lower compared to the control (p<0.05). PhTX-343 group had significantly higher numbers of nuclei within 100 μm length and 100 μm2 area of GCL (2.9- and 1.7-fold, respectively) compared to NMDA group (p<0.05). PhTX-343 group also displayed lesser optic nerve fibres degeneration compared to NMDA group which showed vacuolation in all sections. In the visual behaviour test, the NMDA group recorded higher total distance travelled, and lower total immobile time and episodes compared to the control and PhTX-343 groups (p<0.05). Object recognition tests showed that the rats in PhTX-343 group could recognize objects better, whereas the same objects were identified as novel by NMDA rats despite multiple exposures (p<0.05). Visual performances in the PhTX-343 group were all comparable with the control (p>0.05). These findings suggested that PhTX-343 inhibit retinal cell loss, optic nerve damage, and visual impairments in NMDA-induced rats.