The ongoing stream of human consciousness relies on two distinct cortical systems, the default mode network and the dorsal attention network, which alternate their activity in an anticorrelated manner. We examined how the two systems are regulated in the conscious brain and how they are disrupted when consciousness is diminished. We provide evidence for a “temporal circuit” characterized by a set of trajectories along which dynamic brain activity occurs. We demonstrate that the transitions between default mode and dorsal attention networks are embedded in this temporal circuit, in which a balanced reciprocal accessibility of brain states is characteristic of consciousness. Conversely, isolation of the default mode and dorsal attention networks from the temporal circuit is associated with unresponsiveness of diverse etiologies. These findings advance the foundational understanding of the functional role of anticorrelated systems in consciousness.
Cdh1
is a regulatory subunit of the anaphase promoting complex/cyclosome
(APC/C), known to be involved in regulating neuronal survival. The
role of Cdh1 in volatile anesthetics-induced neuronal apoptosis in
the developing brain is unknown. In this study, we used postnatal
day 7 (P7) and day 21 (P21) mice exposed to 2.3% sevoflurane for 6
h to investigate at which age and duration of exposure sevoflurane
affects the expression of Cdh1 and glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase
3 (PFKFB3) and that of the pentose phosphate pathway (PPP) enzyme,
glucose-6-phosphate dehydrogenase (G6PD). Furthermore, we tested whether
the cyclin-dependent kinases (cdks) inhibitor roscovatine could counteract
the effects caused by exposure to sevoflurane. Finally, we applied
the glycolysis inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one
(3-PO), G6PD inhibitor dehydroepiandrosterone (DHEA), and exogenous
reduced glutathione to examine the contribution of the glycolysis
pathway and PPP to sevoflurane-induced neuroapoptosis. We found that
prolonged sevoflurane anesthesia significantly reduces the Cdh1 level
in P7 mice compared to in the P21 ones; moreover, the decrease in
Cdh1 level results in a switch in glucose metabolism from the PPP
to neuronal glycolysis. This leads to an imbalance between reactive
oxygen species production and reduced glutathione level in the developing
brain, which is more susceptible to oxidative stress. As a result,
sevoflurane induces neuroapoptosis through Cdh1-mediated glucose metabolism
reprogramming. Our study demonstrates a critical role of Cdh1 in sevoflurane-induced
neuroapoptosis by shifting PPP to the glycolytic pathway in the developing
brain. These findings suggest that Cdh1 may be a novel target for
preventing volatile anesthetics-induced neurotoxicity and memory impairment.
Introduction: Tranexamic acid reduces blood loss and allogeneic transfusion requirements in various surgical procedures. The role of tranexamic acid during cytoreductive procedures in advanced ovarian cancer is not clear.
Material and methods:This was a single center randomized, controlled, three-armed clinical trial. A total of 150 ovarian cancer patients undergoing cytoreductive surgery were recruited and assigned to three groups (n = 50/group): the control group (normal saline), low-dose group (10 mg/kg bolus + 1 mg/kg continuous infusion of tranexamic acid), and high-dose group (20 mg/kg bolus + 5 mg/kg continuous infusion of tranexamic acid). The primary endpoint was intraoperative blood loss volume and total blood loss volume, and secondary endpoints included intraoperative blood transfusion volumes, vasoactive agent consumption, admission into the intensive care unit, and incidence of postoperative complications within postoperative 30 days. The study was registered at Clini calTr ials.gov ID: NCT04360629.
Results:The patients in the high-dose group had less intraoperative (median [IQR]: 625.3 mL [343.5-1210.5]) and total blood loss volume (748.9 mL [292.2-1650.2]) than those in the control group (1015.5 mL [679.4-1015.5], p = 0.012; and 1700.7 mL [458.7-2419.8], p = 0.004, respectively). In contrast, the intraoperative (992.5 mL [539.0-1404.0], p = 0.874) and total blood loss volume (1025.0 mL [381.8-1819.9], p = 0.113) was not significantly reduced in the low-dose group when compared with the control group. Correspondingly, the relative risk of blood transfusion (RR [95% CI], 0.405 [0.180-0.909], p = 0.028) was reduced in the high-dose group and required less intraoperative noradrenaline (881.0 ± 438.3 mg) to maintain stable hemodynamics than the control group (1548.0 ± 349.8 mg, p = 0.001). Furthermore, compared with the control group, the two tranexamic acid groups had decreased intensive care unit
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