Objective To verify the accuracy of Youssef's formula and evaluate whether fetal biacromial diameter(BA)and other fetal biological diameters estimated by ultrasound can be used to predict macrosomia and shoulder dystocia,so as to provide the possibility for clinical prediction of shoulder dystocia.Methods A total of 200 pregnant women with a gestational period of 37-42 weeks were examined with ultrasound within 3 days before delivery for collecting biparietal diameter(BPD),head circumference(HC),abdominal circumference(AC),humerus length(HL),femur length(FL),thoracic transverse diameter and midpoint diameter of upper arm;and the fetal BA was estimated by Youssef's formula.Neonatal BA,body mass and body length were measured within 1 day after delivery.The above data were analyzed for correlation.Newborns were grouped according to their body mass(macrosomia vs non-macrosomia)and whether they had shoulder dystocia or not(shoulder dystocia vs non-shoulder dystocia).Results(1)The fetal BA estimated by Youssef's formula was consistent with neonatal BA(P>0.05),and the estimated BA was positively correlated with BPD,HC,AC and neonatal body mass(P<0.001).(2)The BA,BA/AC and BA/HC in macrosomia group were different from those in non-macrosomia group(P<0.05).ROC curve showed that the sensitivity and specificity were 92.3%and 88.2%for macrosomia prediction when the estimated BA threshold was 16.05 cm,and those were 61.5%and 77.0%when BA/AC threshold was 0.455,and 76.9%and 72.7%when BA/HC threshold was 0.465.(3)Shoulder dystocia group had neonatal weight close to non-shoulder dystocia group(P>0.05),but higher BA/BPD,BA/HC and BA-BPD(P<0.05).ROC curve showed that the sensitivity and specificity were 100.0%and 66.8%for shoulder dystocia when BA threshold was 15.45 cm,100.0%and 80.6%when BA/BPD threshold was 1.695,100.0%and 81.6%when BA/HC threshold was 0.475,and 100.0%and 76.0%when the threshold difference between BA and BPD was 6.35 cm.Conclusion Fetal BA,BA/BPD,BA/HC,BA/AC and BA-BPD may be effective predictors of shoulder dystocia and macrosomia.

Objective To investigate the protective effect and mechanism of heat acclimation(HA)on electromagnetic field(EMF)induced hippocampus neuron injury in mice.Methods Forty healthy BALB/c male mice(18～22 g,7 weeks old)were randomly divided into 4 groups(n=10):Control group(Con),HA group(34℃,30 d),EMF group(2 450 MHz,20 min/d,4 weeks)and HA+EMF group(HA preconditioning+EMF).Sucrose preference test was performed to evaluate sucrose preference levels of mice in each group.Tail suspension test and forced swimming test were utilized to observe the immobility time.Morris water maze test was conducted to determine the learning and memory capabilities.Pathological changes in the hippocampus were observed with HE staining.Immunohistochemical assay for Iba1(marker of microglia),CD68(marker of pro-inflammatory phenotype)and CD206(marker of anti-inflammatory phenotype)were used to detect the number and activation phenotype of microglia in the hippocampus.ELISA was applied to measure the levels of TNF-α,IL-1β,TGF-β and IL-10 in the hippocampus of each group.Western blotting was performed to determine the protein levels of HSP70 in the hippocampus.Results As compared with the Con group,the EMF group showed a decreased preference for sucrose(P<0.05),prolonged immobile time in the tail suspension test(P<0.01)as well as in the forced swimming test(P<0.01),extented escape latency on the 7th day(P<0.01),and a decreased time of crossing the platform(P<0.05).EMF exposure resulted in that the hippocampal neurons were in disordered arrangement,loose structure and irregular morphology,with swollen cytoplasm and condensed nuclei,swollen and more microglial cells in the hippocampus(P<0.01),and enhanced relative fluorescence intensity of CD68(P<0.01),but not in CD206 fluorescence intensity(P=0.885).All these findings suggested that activated microglia predominantly exhibited a pro-inflammatory M1 phenotype during this phase.In the hippocampus,the levels of TNF-α and IL-1β were significantly increased,while the levels of IL-10 and TGF-β were significantly decreased(P<0.01).HA treatment reversed the conditions induced by EMF exposure,including better preference for sucrose(P<0.01),shorten immobile time in tail suspension test(P<0.05)and forced swimming test(P<0.01),less escape latency on the 7th day(P<0.01),and improved hippocampal cell injuries.Compared with the Con group,there were more microglial cells in the hippocampus in the HA+EMF group,with increased relative fluorescence intensity of M2 phenotype marker CD206(P<0.01)and decreased CD68 fluorescence intensity(P<0.01).HA treatment also significantly decreased the expression of TNF-α and IL-1β levels(P<0.01),increased the expression of IL-10 and TGF-β(P<0.01),and elevated the protein level of HSP70(P<0.01)when compared with the EMF group.Conclusion HA may ameliorate EMF-induced hippocampus neurons injury in mice by altering the phenotype of activated microglia and inhibiting inflammatory responses.

Objective To verify the accuracy of Youssef's formula and evaluate whether fetal biacromial diameter(BA)and other fetal biological diameters estimated by ultrasound can be used to predict macrosomia and shoulder dystocia,so as to provide the possibility for clinical prediction of shoulder dystocia.Methods A total of 200 pregnant women with a gestational period of 37-42 weeks were examined with ultrasound within 3 days before delivery for collecting biparietal diameter(BPD),head circumference(HC),abdominal circumference(AC),humerus length(HL),femur length(FL),thoracic transverse diameter and midpoint diameter of upper arm;and the fetal BA was estimated by Youssef's formula.Neonatal BA,body mass and body length were measured within 1 day after delivery.The above data were analyzed for correlation.Newborns were grouped according to their body mass(macrosomia vs non-macrosomia)and whether they had shoulder dystocia or not(shoulder dystocia vs non-shoulder dystocia).Results(1)The fetal BA estimated by Youssef's formula was consistent with neonatal BA(P>0.05),and the estimated BA was positively correlated with BPD,HC,AC and neonatal body mass(P<0.001).(2)The BA,BA/AC and BA/HC in macrosomia group were different from those in non-macrosomia group(P<0.05).ROC curve showed that the sensitivity and specificity were 92.3%and 88.2%for macrosomia prediction when the estimated BA threshold was 16.05 cm,and those were 61.5%and 77.0%when BA/AC threshold was 0.455,and 76.9%and 72.7%when BA/HC threshold was 0.465.(3)Shoulder dystocia group had neonatal weight close to non-shoulder dystocia group(P>0.05),but higher BA/BPD,BA/HC and BA-BPD(P<0.05).ROC curve showed that the sensitivity and specificity were 100.0%and 66.8%for shoulder dystocia when BA threshold was 15.45 cm,100.0%and 80.6%when BA/BPD threshold was 1.695,100.0%and 81.6%when BA/HC threshold was 0.475,and 100.0%and 76.0%when the threshold difference between BA and BPD was 6.35 cm.Conclusion Fetal BA,BA/BPD,BA/HC,BA/AC and BA-BPD may be effective predictors of shoulder dystocia and macrosomia.

Objective To investigate the effect of microglial derived extracellular vesicles on neuronal damage in the context of heat stress.Methods After BV2 microglial cells were exposed to heat stress,the supernatant was collected and subjected to ultracentrifugation at different speeds to obtain large and small vesicles,respectively.Nano Particle Tracking and Zeta Potential Distribution Analyzer was used to measure and analyze the size distribution of the large vesicles and small vesicles.Western blotting was used to detect the expression of specific vesicle surface markers,TSG101,CD63 and flotillin-1.Microglial extracellular vesicles were labeled with PKH67 dye and then co-cultured with N2a cells to examine the uptake by capacity the neurons.After large and small vesicles derived from microglia after heat stress stimulation were co-cultured with N2a cells,respectively,CCK-8 assay,lactate dehydrogenase (LDH)assay,Trypan blue staining and TUNEL assay were employed to evaluate heat stress induced neuronal damage.Results The small vesicles were in a particle size of 30～120 nm,and highly expressed TSG101 and CD63,whereas the large vesicles,in a size of 90～1000 nm,highly expressed flotillin-1.The BV2-derived extracellular vesicles could be taken up by N2a cells and were proved to be involved in the modulation of N2a cell injury caused by heat stress.CCK-8 assay showed that both large and small vesicles of microglial cells inhibited the viability of N2a cells after heat exposure (P<0.05).The results of LDH assay,Trypan blue staining and TUNEL assay showed that both large (P<0.05)and small vesicles (P<0.01)significantly enhanced the LDH release,blue stain intensity and apoptosis of N2a cells after heat exposure,and the release,intensity and apoptosis were stronger in the cells treated with small vesicles than those group of large vesicles.Conclusion Microglia aggravate heat stress-induced neuronal damage through releasing extracellular vesicles.

Objective To explore the protective effect and underlying mechanism of roxadustat(FG-4592),hypoxia-inducible factor-α(HIF-α)prolyl hydroxylase inhibitor,on brain injury caused by heat stroke(HS).Methods A total of 140 male C57BL/6J mice(6～8 weeks old,weighing 18～22 g)were subjected,and 40 of them were randomly divided into HS group,and low-,medium-and high-dose roxadustat groups(LD,MD and HD groups,5,10 and 20 mg/kg),with 10 mice in each group.The 24-hour survival rate was observed to determine the optimal dosage of roxadustat after modeling.Additionally,the remaining 100mice were randomly allocated to normal control(Control)group,roxadustat(FG-4592)group,HS group,and roxadustat+HS(FG-4592+HS)group,with 25 mice in each.Heat shock was inflicted to establish mouse model of HS.Modified neurological severity score(mNSS)was used to assess neurological function.HE staining of brain sections was performed to examine pathological damage,and Fluoro-Jade C staining was applied to observe neuronal degeneration.The activity of total superoxide dismutase(SOD)and content of malondialdehyde(MDA)in brain tissue were measured to assess oxidative stress.Transmission electron microscopy was employed to visualize mitochondrial damage.Western blotting was performed to assess the protein levels of Caspase-3,Cleaved Caspase-3,Mfn1,Mfn2,Opa1,Fis1,HIF-1α,HO-1 and p-Drp1(Ser616)/Drp1 ratio in the cerebral cortex.Results Compared to the HS group,FG-4592 significantly improved the survival rate of HS mice within 24 h,with the MD group showing the highest survival rate.Compared to the Control group,the HS group showed an increase in mNSS score(P＜0.05),an elevation in the MDA content in the cerebral cortex(P＜0.05),and a decrease in total SOD activity in the cerebral cortex(P＜0.05);HE staining revealed pathological damage in the cerebral cortex,and Fluoro-Jade C staining displayed obvious neuronal degeneration in the cerebral cortex;Electron microscopy revealed obvious mitochondrial structural damage in the cerebral cortex tissue;The protein expression of Caspase-3,Cleaved Caspase-3,Fis1,HIF-1α,HO-1 and p-Drp1(Ser616)/Drp1 ratio was increased(P＜0.05),while that of Mfn1,Mfn2,and Opa1 was decreased(P＜0.05).Pretreatment with FG-4592 significantly reduced the mNSS score in HS mice(P＜0.05),decreased MDA content(P＜0.05),and enhanced total SOD activity(P＜0.05).Additionally,FG-4592 pretreatment improved pathological damage in the cerebral cortex,reduced neuronal degeneration,and mitigated mitochondrial structural damage.Furthermore,it decreased the protein levels of Caspase-3,Cleaved Caspase-3,Fis1 and p-Drp1(Ser616)/Drp1 ratio(P＜0.05),while increased the levels of Mfn1,Mfn2,Opa1,HIF-1α,and HO-1(P＜0.05).Conclusion Roxadustat regulates the balance between mitochondrial fission and fusion,reduces mitochondrial structural damage,oxidative stress and apoptosis,and alleviates heat stroke-induced brain injury.

Objective:To evaluate the effect of continuous positive airway pressure (CPAP) ventilation during induction of anesthesia on perioperative atelectasis and oxygenation in elderly patients.Methods:Forty-six elderly patients of either sex, aged 65-80 yr, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective cerebrovascular intervention surgery under general anesthesia, were divided into 2 groups ( n=23 each) according to the random number table method: control group (group C) and CPAP ventilation group (group CPAP). During induction of anesthesia, CPAP was set at 5 cmH 2O during spontaneous breathing, and PEEP was set at 5 cmH 2O when spontaneous breathing disappeared, and the ventilation mode was changed to pressure-controlled ventilation (PCV) mode in group CPAP. CPAP was not set, and PEEP was set at 0 cmH 2O for PCV when spontaneous breathing disappeared in group C. During anesthesia maintenance, PCV-volume guaranteed mode was used in both groups, and PEEP was set at 5 cmH 2O. Whole lung CT scanning was performed immediately after radial artery catheterization (T 0), at 1 min after endotracheal intubation (T 1), and before tracheal extubation (T 2) at the end of operation to calculate the percentage of atelectasis area at 1 cm above the right diaphragm. At T 0, T 1, T 2 and 30 min after entering postanesthesia care unit (T 3), blood samples from the radial artery were taken to record PaO 2 and PaCO 2 and calculate the oxygenation index (OI). Results:Compared with the baseline at T 0, the percentage of atelectasis area was significantly increased at T 1 and T 2 in two groups ( P<0.05); PaO 2 was significantly increased at T 1 and T 2 and decreased to T 0 level at T 3, OI was decreased at T 1 and T 2 and increased to T 0 level at T 3 in two groups ( P<0.05). Compared with group C, the percentage of atelectasis area was significantly decreased and PaO 2 and OI were increased at T 1 and T 2 in group CPAP ( P<0.05). There was no significant difference in PaCO 2 at each time point between the two groups ( P>0.05). Conclusions:CPAP ventilation during induction of anesthesia can reduce the development of perioperative atelectasis and improve the oxygenation in elderly patients.

Objective:To evaluate the effect of continuous positive airway pressure(CPAP) ventilation strategy during induction of general anesthesia on atelectasis after induction in obese patients.Methods:A total of 86 patients, aged 30-60 yr, with body mass index of 28-35 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱor Ⅲ, scheduled for elective cerebrovascular intervention under general anesthesia, were divided into 2 groups ( n=43 each) using a random number table method: CPAP group (group C) and routine group (group R). Group C received CPAP 5 cmH 2O-assisted ventilation after preoxygenation for spontaneous breathing and disappearance of spontaneous breathing. Chest CT scan and arterial blood gas analysis were performed after entering the operating room (T 1) and 5 min after endotracheal intubation (T 2) to calculate the percentage of atelectasis area and to record PaO 2. Dynamic lung compliance and plateau pressure were recorded at T 2. Mean minute ventilation under controlled breathing, P ETCO 2, and use of vasoactive drugs during induction were recorded. The occurrence of reflux and aspiration during mask ventilation was recorded. The development of pulmonary complications within 3 days after operation was recorded. Results:Compared with group R, the percentage of atelectasis area at T 2 was significantly decreased, PaO 2, dynamic lung compliance and plateau pressure were increased ( P<0.05), and no significant change was found in mean minute ventilation, P ETCO 2, requirement for vasoactive drugs and incidence of pulmonary complications in group C ( P>0.05). No reflux or aspiration was observed during mask ventilation. Conclusions:CPAP (5 cmH 2O) strategy during anesthesia induction can reduce the degree of atelectasis after induction in obese patients.