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Liem, B. T.

Publications and source records attributed to Liem, B. T..

2 recordsLinked to original sources

Reduced parenteral glucose supply in preterm neonatal infection ameliorates the pulmonary damage

Preterm infants are acutely susceptible to neonatal sepsis, a syndrome characterized by systemic pro-inflammatory activity and life-threatening multi-organ dysfunction. However, the specific pulmonary pathological response to sepsis and the potential for metabolic interventions to mitigate lung injury remain poorly characterized. Herein, we evaluated the impact of varying parenteral glucose regimens on pulmonary outcomes during severe infection using a preterm piglet model. Genome-wide gene expression analysis was used to characterize lung transcriptome profiles. The relationships between gene expression and circulating biochemical and immune profiles were also investigated. Our findings demonstrate that significant pulmonary tissue damage is a hallmark of neonatal sepsis. A reduced-glucose regimen markedly attenuated pulmonary tissue damage while simultaneously alleviating systemic metabolic acidosis and hyperlactatemia. Mechanistically, lung transcriptome profiling revealed a profound activation of pathways associated with inflammatory signaling, programmed cell death, and the dysregulation of glucose, amino acid, and lipid metabolism. The low-glucose intervention effectively mitigated these widespread molecular and metabolic disturbances, suggesting a restorative effect on the pulmonary transcriptome landscape. To facilitate further mechanistic exploration and the identification of novel therapeutic targets, we developed the NeoSepPulmoExplorer (https://pharmaco-omicslab.shinyapps.io/NeoSepPulmoExplorer/), an interactive web-based toolkit for better mechanistic understanding and the identification of potential treatment targets. These results collectively underscore the importance of metabolic modulation in preserving organ function, though further translational studies are requisite to improve clinical outcomes in septic neonates.

immunology↗

Layer Dependence of Monocular and Binocular Responses in Human Ocular Dominance Columns at 7T using VASO and BOLD

The neurons located in the striate cortex (V1) preferentially respond to the input from one eye or another, forming a fingerprint-like pattern of ocular dominance columns (ODCs). At this mesoscopic scale, accessible by ultra-high field fMRI, V1 is supplied/drained by a network of surface (pial) vessels that connect to descending/ascending tangential vessels that penetrate the cortex and supply/drain a capillary bed whose density is also layer dependent. In this study, we measured the layer dependence of monocular and binocular responses of ocular dominance columns in V1 at 7T using Blood Oxygenation Level Dependent (BOLD) and VAscular Space Occupancy (VASO) contrasts. Our results indicate that the microvascular blood volume changes that give rise to VASO are well confined to the site of neural activity across the layers of the cortex and between the columns. Pial veins dominate the BOLD response and mix the signal between columns. When the GRE BOLD response was examined in only the VASO specific voxels (thus eliminating the pial vein signal), the laminar profile was very similar to VASO, however, the columnar response was still blurred. Caution needs to be exercised in the interpretation of signal changes in BOLD at the mesoscale both in terms of feedforward/feedback effects and inhibitory and excitatory effects. Highlights- VASO produced laminar profiles that were consistent with the known layer-dependent neuronal response to monocular and binocular stimulations. - VASO better differentiated the response between columns belonging to the left and right eyes. - GRE BOLD signal spatial specificity was poor in both laminar and columnar directions, however, when the pial veins were suppressed, the laminar BOLD signal was very similar to the VASO signal. - Caution needs to be exercised when interpreting cognitive neuroscience BOLD studies at the mesoscale level due to the confounding effects of pial and sub-pial veins and venules.

neuroscience↗