In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus ...In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm,environmental zeitgebers are used by the circadian system.This is done primarily by signals from the retina via the retinohypothalamic tract,but other cues like exercise,feeding,temperature,anxiety,and social events have also been shown to act as non-photic zeitgebers.The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise.Irisin is a product of cleavage and modification from its precursor membrane fibronectin typeⅢdomain-containing protein 5(FNDC5)in response to exercise.Apart from well-known peripheral effects,such as inducing the"browning"of white adipocytes,irisin can penetrate the blood-brain barrier and display the effects on the brain.Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions.In several brain areas,irisin induces the production of brain-derived neurotrophic factor(BDNF).In the master clock,a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested.However,the brain receptor for irisin remains unknown.In the current review,the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.展开更多
Myocardial protection during open heart surgery was studied in 52 patients with complex congenital heart disease. Twenty-six patients received b1ood cardioplegia (BCP) and 26 crystalloid cardioplegia (CCP). Release of...Myocardial protection during open heart surgery was studied in 52 patients with complex congenital heart disease. Twenty-six patients received b1ood cardioplegia (BCP) and 26 crystalloid cardioplegia (CCP). Release of serum enzymes (creatine kinase, CK; hybrid muscle-brain CK isoenzyme, CK-MB; aspartate aminotransferase, ASTF and 1actic dehydrogenase, LDH) was determined pre-and post-operatively. DUring the first 72 h post-operation, release of CK, CK-MB, AST and LDH in the 2 groups was different, In case of tetralogy of Fallot (TOF) the CK-MB released in l3CP and CCP 12 h after operation were 51. 29±9. 42 and 85. 77±22. 39 U/L respectively (P<0. 05). In the CCP group of TOF, CK-MB level increased significantly even at 72 h after operation (30. 91±14. 32 U/L vs the pre-operative value of 14. 57±7. 51 U/L). The results show a better myocardial preservation in the BCP group as compared with the CCP group. BCP can maintain metabolic homeostasis of the myocardium, reduce myocardial injury and increase the content of myocardial high energy phosphate during ischemia. Tolerance to ischemia is poor in patients with complex congenital heart disease. Therefore, preservation of high energy phosphates is necessary for severe-grade patients and BCP is superior to crysta1loid cardioplegia in this regard. It is concluded that CCP results in a higher release of CK-MB as compared with BCP group. BCP is superior to CCP for myocardial protection in patients with complex congenital heart disease.展开更多
基金supported by the Russian Science Foundation(Grant No.23-25-00152).
文摘In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm,environmental zeitgebers are used by the circadian system.This is done primarily by signals from the retina via the retinohypothalamic tract,but other cues like exercise,feeding,temperature,anxiety,and social events have also been shown to act as non-photic zeitgebers.The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise.Irisin is a product of cleavage and modification from its precursor membrane fibronectin typeⅢdomain-containing protein 5(FNDC5)in response to exercise.Apart from well-known peripheral effects,such as inducing the"browning"of white adipocytes,irisin can penetrate the blood-brain barrier and display the effects on the brain.Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions.In several brain areas,irisin induces the production of brain-derived neurotrophic factor(BDNF).In the master clock,a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested.However,the brain receptor for irisin remains unknown.In the current review,the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.
文摘Myocardial protection during open heart surgery was studied in 52 patients with complex congenital heart disease. Twenty-six patients received b1ood cardioplegia (BCP) and 26 crystalloid cardioplegia (CCP). Release of serum enzymes (creatine kinase, CK; hybrid muscle-brain CK isoenzyme, CK-MB; aspartate aminotransferase, ASTF and 1actic dehydrogenase, LDH) was determined pre-and post-operatively. DUring the first 72 h post-operation, release of CK, CK-MB, AST and LDH in the 2 groups was different, In case of tetralogy of Fallot (TOF) the CK-MB released in l3CP and CCP 12 h after operation were 51. 29±9. 42 and 85. 77±22. 39 U/L respectively (P<0. 05). In the CCP group of TOF, CK-MB level increased significantly even at 72 h after operation (30. 91±14. 32 U/L vs the pre-operative value of 14. 57±7. 51 U/L). The results show a better myocardial preservation in the BCP group as compared with the CCP group. BCP can maintain metabolic homeostasis of the myocardium, reduce myocardial injury and increase the content of myocardial high energy phosphate during ischemia. Tolerance to ischemia is poor in patients with complex congenital heart disease. Therefore, preservation of high energy phosphates is necessary for severe-grade patients and BCP is superior to crysta1loid cardioplegia in this regard. It is concluded that CCP results in a higher release of CK-MB as compared with BCP group. BCP is superior to CCP for myocardial protection in patients with complex congenital heart disease.
