Objective To investigate the effect of pregnancy on the potency of bupivacaine for spinal anesthesia in rats. Methods Female non-pregnant SD rats weighing 180-220 g and 17 day pregnant SD rats weighing 350-400 g were used in this study. The rats ( 18 non-pregnant, 18 pregnant) in which PE-10 catheter were successfully placed without complications were selected. The 18 non-pregnant rats were randomly divided into 3 groups (n =6 each): control group (group C), 2% bupivacaine group (group B2 ) and 4% bupivacaine group (group B4). The 18 pregnant rats were also randomly divided into 3 groups (n = 6 each): control group (group PC),2% bupivacaine group (group PB2 ) and 4% bupivacaine group (group PB4 ). Group C and PC received intrathecal (IT) normal saline 30 μl, and the other 4 groups received 2% or 4% bupivacaine 30 μl intrathecally. Analgesia was determined using the taifllick latency (TFL) before IT administration (baseline), and at 10 min, 20 min,30 min, 1 h, 2 h, 4 h, 1 d, 2 d, 3 d and 4 d after IT administtation. The percentage of the maximal possible effect (MPE) was calculated. Hind-limb motor function (MF) was also assessed. Results Compared with the baseline value, MPE at 10 min-2 h after administration and MF scores at 10 min-1 h after administration were significantly increased in group B2, MPE at 10 min-4 h after administration and MF scores at 10 min-1 h after administration were significantly increased in group B4;MPE at 10 min-1 d after administration and MF scores at 10 min2 h were significantly increased in group PB2 and MPE at 10 min-1 d after administration and MF scores at 10 min4 h were significantly increased in group PB4 ( P ＜ 0.05 ). Conclusion Pregnancy can enhance the potency of bupivacaine for spinal anesthesia in rats.

ObjectiveWe conducted a two-sample Mendelian randomization （MR） study to assess the causal relationship between circulating isoleucine， leucine and valine levels and the risk of peripheral atherosclerosis. MethodsBased on the large-scale genome-wide association study （GWAS） database， single nucleotide polymorphisms （SNPs） closely related to the circulating levels of isoleucine， leucine and valine were identified as instrumental variables （IVs）. Two-sample MR analysis applying the inverse variance weighted （IVW） method and the weighted median estimator （WME） method were performed to estimate the causal relationship between the risk of peripheral atherosclerosis and the exposure with more than three SNPs that were available as IVs. The pleiotropy was evaluated by using the MR-Egger regression and MR-PRESSO method， and the leave-one-out method was used in sensitivity analysis. ResultsFour， one and one SNPs were identified as IVs for circulating isoleucine， leucine and valine levels， respectively. For isoleucine， the IVW model demonstrated there was no evidence of heterogeneity among the IVs （P=0.715）， and there was a significant causal relationship between the increase of circulating isoleucine level and a higher risk of peripheral atherosclerosis risk. Per every 1 elevated standard deviation （SD） of circulating isoleucine level resulted in increasing 31% of peripheral atherosclerosis risk （OR=1.31， 95%CI： 1.07‒1.61）. Similarly， the OR（95%CI） was 1.33 （1.04‒1.71） in the WME model. The MR-Egger regression and MR-PRESSO analysis indicated no evidence of pleiotropy in IVs （all P>0.05）. The result of the leave-one-out sensitivity analysis was stable. The Wald ratio model displayed that the causal relationship between circulating leucine and valine levels and the risk of peripheral atherosclerosis was not statistically significant. The OR （95%CI） for leucine and valine was 1.13 （0.78‒1.63） and 1.11 （0.82‒1.50）， respectively. ConclusionThere is a significant causal relationship between the increase of circulating isoleucine level and a higher peripheral atherosclerosis risk. The causal relationships between circulating leucine and valine levels and the risk of peripheral atherosclerosis need to be further confirmed in future studies.

ObjectiveThis research focused on examining the distinctive characteristics of nutrient intake and dietary patterns among long-lived elderly individuals. Additionally， the study was aimed to explore the specific dietary components that may impact the skeletal muscle mass in this particular group. MethodsThis study was conducted in the Chongming area of Shanghai， China. A total of 206 long-lived elderly individuals aged 90 or above were recruited. The 3-day 24-hour dietary recall method was used to collect dietary information and general demographic data through face-to-face interviews with professional nutritionists. The skeletal muscle mass index（SMI） was measured by bioelectrical impedance analysis（BIA）， and low skeletal muscle mass was diagnosed based on the 2019 Asian Working Group for Sarcopenia criteria. T-test analysis， chi-square test， and logistic regression were used to analyze the relationship between dietary nutrient intake and skeletal muscle mass. ResultsIn terms of food intake categories， compared with the long-lived elderly people with normal muscle mass， the intake of cereals containing miscellaneous beans and vegetables in the long-lived elderly people with low muscle mass was significantly lower（P<0.05）. In terms of the nutrient intake， compared with the long-lived elderly people with normal muscle mass， the intake of total energy， carbohydrate， dietary fiber， vitamin D， folic acid， phosphorus， potassium， magnesium， iron， and manganese in the long-lived elderly people with low muscle mass was significantly lower（P<0.05）. After continuous adjustment for the covariates， multivariate logistic regression analysis found that the intake levels of folic acid and dietary fiber were important factors influencing skeletal muscle mass， Individuals with lower intake levels of folic acid and dietary fiber are at a higher risk of low muscle mass in long-lived elderly individuals ［OR_{folic acid T1}， _{dietary fiber T1} （95%CI）： 2.90 （1.11‒7.61）； 4.09 （1.53‒10.91）］. ConclusionThe consumption of cereals that include a variety of beans and vegetables was noticeably lower in the long-lived elderly individuals with lower muscle mass when compared to those with normal muscle mass. Furthermore， low levels of folic acid and dietary fiber intake are associated with an increased risk of low skeletal muscle mass.