Objective To investigate the effects of different inspired oxygen concentrations on periop-erative cerebrovascular function in patients with a history of ischemic stroke.Methods A total of 150 patients scheduled for elective surgery with a history of ischemic stroke were enrolled from Renji Hospital,Shanghai Jiao Tong University School of Medicine,between June 2020 and March 2024.Using a random number table,patients were allocated into two groups:F30 group(intraoperative fraction of inspired oxygen,FiO2=30%)and F80 group(FiO2=80%),with 75 patients in each group.Bilateral middle cerebral artery(MCA)blood flow was continu-ously monitored using transcranial Doppler(TCD),including mean flow velocity(Vm),resistance index(RI),and pulsatility index(PI).Cerebral oxygen saturation(rScO2)was measured using a FORE-SIGHT oximeter.Arterial blood gas analysis was performed preoperatively,1 hour after induction,and before extubation to assess pH,partial pressure of arterial carbon dioxide(PaCO2),oxygenation index(OI),base excess(BE),hematocrit(Hct),and lactate(Lac).Peripheral blood samples were collected 24 hours postoperatively to measure thrombox-ane A2(TXA2)and prostacyclin(PGI2)levels.At 1 month postoperatively,telephone follow-up was conducted to evaluate the risk of recurrent cerebral ischemic events using the ABCD2 score and Essen Stroke Risk Score(ESRS).Results No significant differences were observed in baseline characteristics between the two groups.Perioperative arterial blood gas parameters did not differ significantly between groups(P>0.05).Compared with the F30 group,the F80 group exhibited a smaller reduction in mean flow velocity(Vm)of the affected MCA at the end of surgery(8.18%±3.34%vs.13.57%±5.32%,P<0.05),while no significant intergroup differences were found in RI or PI.At 1 hour after induction and before extubation,rScO2 of the affected hemisphere was signifi-cantly increased in the F80 group as compared with the F30 group(P<0.05),whereas no significant difference was observed in the contralateral hemisphere.Before extubation and on postoperative day 1,TXA2 levels were significantly lower and PGI2 levels higher in F80 group compared with F30 group(P<0.05).The proportion of patients at high risk of cerebral ischemia by ABCD2 and ESRS at 1 month postoperatively did not differ between groups(P>0.05).Conclusion In patients with a history of stroke,intraoperative administration of 80%FiO2under general anesthesia better maintains perioperative cerebral hemodynamic stability and cerebral oxygen satura-tion,improves cerebrovascular endothelial function,but does not significantly affect the short-term incidence of postoperative cerebrovascular events compared with 30%FiO2.

Objective To investigate the effects of different inspired oxygen concentrations on periop-erative cerebrovascular function in patients with a history of ischemic stroke.Methods A total of 150 patients scheduled for elective surgery with a history of ischemic stroke were enrolled from Renji Hospital,Shanghai Jiao Tong University School of Medicine,between June 2020 and March 2024.Using a random number table,patients were allocated into two groups:F30 group(intraoperative fraction of inspired oxygen,FiO2=30%)and F80 group(FiO2=80%),with 75 patients in each group.Bilateral middle cerebral artery(MCA)blood flow was continu-ously monitored using transcranial Doppler(TCD),including mean flow velocity(Vm),resistance index(RI),and pulsatility index(PI).Cerebral oxygen saturation(rScO2)was measured using a FORE-SIGHT oximeter.Arterial blood gas analysis was performed preoperatively,1 hour after induction,and before extubation to assess pH,partial pressure of arterial carbon dioxide(PaCO2),oxygenation index(OI),base excess(BE),hematocrit(Hct),and lactate(Lac).Peripheral blood samples were collected 24 hours postoperatively to measure thrombox-ane A2(TXA2)and prostacyclin(PGI2)levels.At 1 month postoperatively,telephone follow-up was conducted to evaluate the risk of recurrent cerebral ischemic events using the ABCD2 score and Essen Stroke Risk Score(ESRS).Results No significant differences were observed in baseline characteristics between the two groups.Perioperative arterial blood gas parameters did not differ significantly between groups(P>0.05).Compared with the F30 group,the F80 group exhibited a smaller reduction in mean flow velocity(Vm)of the affected MCA at the end of surgery(8.18%±3.34%vs.13.57%±5.32%,P<0.05),while no significant intergroup differences were found in RI or PI.At 1 hour after induction and before extubation,rScO2 of the affected hemisphere was signifi-cantly increased in the F80 group as compared with the F30 group(P<0.05),whereas no significant difference was observed in the contralateral hemisphere.Before extubation and on postoperative day 1,TXA2 levels were significantly lower and PGI2 levels higher in F80 group compared with F30 group(P<0.05).The proportion of patients at high risk of cerebral ischemia by ABCD2 and ESRS at 1 month postoperatively did not differ between groups(P>0.05).Conclusion In patients with a history of stroke,intraoperative administration of 80%FiO2under general anesthesia better maintains perioperative cerebral hemodynamic stability and cerebral oxygen satura-tion,improves cerebrovascular endothelial function,but does not significantly affect the short-term incidence of postoperative cerebrovascular events compared with 30%FiO2.

Matteuccia struthiopteris is a nature plant, which contains a lot of potential active components. In the present study, we investigated the effect of polysaccharides extracted from Matteuccia struthiopteris on lupus-like syndrome induced by Campylobacter jejuni CJ-S131 in BALB/c mice. Mice were randomly divided into normal, model control, SLE model (vehicle treated), Matteuccia struthiopteris polysaccharides treated (30 and 15 mg x kg(-1)) groups and prednisone 5 mg x kg(-1) treated groups. The effect of Matteuccia struthiopteris polysaccharides (Ms) on weight and organ index of BALB/c mice was detected. Autoantibodies and total IgG production were measured by enzyme linked immunosorbent assay. Proteinuria was measured and kidneys were examined by light microscopy. Compared with SLE model group, treatment with Matteuccia struthiopteris polysaccharides 30 and 15 mg x kg(-1) reduced weight loss and Matteuccia struthiopteris polysaccharides 15 mg x kg(-1) reduced spleen swelling (P < 0.05). The increased production of autoantibodies and total immunoglobulin G (IgG) were also significantly inhibited. Matteuccia struthiopteris polysaccharides protected kidney against glomerular injury in BALB/c mice with reduced immunoglobulin deposition and lowered proteinuria (P < 0.01). Matteuccia struthiopteris polysaccharides had a protective effect on lupus-like syndrome induced by CJ-S131 in BALB/c mice.