The effect of dexmedetomidine on haemodynamics during intracranial procedures: a meta-analysis.

OBJECTIVES: Our aim of this study is to compare the effect of Dexmedetomidine versus placebo for patients with cerebral protection during intracranial procedures. METHODS: Rev.Man 5.1 and Stata 11.0 software is used for this study to make analysis, and use a fixed-effects model (the Mantel-Haenszel method) or a random-effects model (the DerSimonian and Laird method) to merge or aggregate the weighted mean difference (WMD) or risk ratio (RR) and its 95% confidence intervals (CI) of included studies. RESULTS: Nine studies involving 404 patients with cerebral protection during intracranial procedures (experimental group: 202; control group: 202) were performed in this study. Significant differences of MAP > 100 mmHg(RR = 0.45, 95%CI = 0.29 to 0.69, P < 0.05), MAP< 60 mmHg (RR = 0.66, 95%CI = 0.43 to 1.00, P = 0.05), MAP when extubation (WMD = -12.57, 95%CI = -16.31 to -8.83, P < 0.05) and heart rate when extubation (WMD = -22.79, 95%CI = -30.57 to -15.01, P < 0.05) were observed between the two groups. There are no significant differences were found in HR > 100 bpm (RR = 0.52, 95%CI = 0.22 to 1.19, P > 0.05) and HR< 50 bpm (RR = 0.86, 95%CI = 0.31 to 2.38, P > 0.05) between the two groups. CONCLUSIONS: Our results suggested that the efficacy of Dexmedetomidine for patients with cerebral protection during intracranial procedures is better than placebo treatment.

Inhibition of mitochondrial permeability transition pore opening contributes to cannabinoid type 1 receptor agonist ACEA-induced neuroprotection.

Cannabinoid type 1 (CB1) receptor agonist arachidonyl-2-chloroethylamide (ACEA) induces neuroprotection against brain ischemia, and the mechanism, however, is still elusive. In this study, we used bilateral common carotid artery occlusion (BCCAO) in mice and oxygen-glucose deprivation (OGD) in primary cultured neurons to mimic brain ischemic injury, and hypothesized that cannabinoid CB1 receptor agonist ACEA protects ischemic neurons via inhibiting the opening of mitochondrial permeability transition pore (MPTP). In vivo, we found that BCCAO treatment reduced the neurological functions, increased the number of apoptotic neuronal cells and deteriorated the mitochondrial morphology in the ischemic brain tissue. And in vitro, we observed that OGD injury reduced cell viability, mitochondrial function and anti-oxidant SOD2 expression, increased lactate dehydrogenase (LDH), mitochondrial cytochrome C (Cyto C) and apoptosis-inducing factor (AIF) releases, elevated the cell apoptosis and mitochondrial superoxide level. And the CB1 receptor agonist ACEA significantly abolished the BCCAO and OGD-induced neuronal injury above. However, the MPTP opener atractyloside (Atr) markedly reversed the ACEA-induced neuroprotective effects, inhibited the mitochondrial Cyto C and AIF releases and relieved the mitochondrial swelling, but the MPTP inhibitor cyclosporin A (CsA) did not cause significant effects on the ACEA-induced neuroprotection above. These findings indicated that inhibition of MPTP opening may be involved in the cannabinoid CB1 receptor agonist ACEA-induced neuroprotection.

A highly efficient asymmetric synthesis of quaternary stereocenter-containing indolizidine and quinolizidine alkaloids using aldehydes, nitroalkenes, and unactivated cyclic ketimines.

A highly efficient approach for the construction of indolizidines and quinolizidines bearing a bridged quaternary stereocenter has been established in a one-pot fashion using aldehydes, nitroalkenes, and cyclic ketimines with excellent enantioselectivities and in high yields. Moreover, this method could be applied to the synthesis of indolizidines in the gram scale.

One-pot enantioselective construction of indoloquinolizidine derivatives bearing five contiguous stereocenters using aliphatic aldehydes, nitroethylenes, and tryptamine.

An organocatalytic cascade reaction was established for the construction of indoloquinolizidine derivatives bearing five contiguous stereocenters from readily available aliphatic aldehydes, nitroethylenes, and tryptamine. This one-pot process gave 30-55% overall yields with excellent d.r. (>20 : 1 in all cases) and ee (91-98%). Additionally, quaternary stereogenic carbon center-containing indoloquinolizidines were prepared through NBS-mediated cyclization of one of the intermediates.