Rats were divided into 6 groups fed with 2 levels of zinc (1.41 and 100 ppm) and 3 levels of vitamin A (retinyl acetate 0, 7 and 46 mg/kg). Each group of the rats was tube-fed for 18 days and killed on the 19th day of experiment. Growth rate, zinc and vitamin A levels in serum and tissues, alkaline phosphatase (AKP) activity in serum, total protein and hemoglobin concentrations were measured. Both zinc levels in serum and tissues and AKP activity of the zinc deficient groups were significantly lower than those of the control group. The serum vitamin A values were distinctively depressed in the vitamin A free and vitamin A normal group. The serum vitamin A values in the vitamin A enriched group were not affected by zinc deficient diet and its serum zinc levels was higher than vitamin A free and normal group. The results suggest that zinc deficiency will interfere the release of vitamin A from liver and lead to the decrease of blood vitamin A, which may occurs only when the blood zinc is lower than a certain "critical level" . Different levels of vitamin A have different effect on rats of zinc deficiency, such as vitamin A deficiency will aggravate the zinc deficient symptoms and the increase of vitamin A intake can alleviate zinc deficient harms.

Objective To explore the diagnostic value of color Doppler ultrasound for fetal intrauterine distress(FIUD)in high-risk puerperae in plateau areas.Methods A total of 130 puerperae in plateau areas and 130 puerperae in plain areas were enrolled.According to presence or absence of FIUD in different areas,they were divided into the plateau distress group(47 cases),the plateau normal group(83 cases),the plain distress group(31 cases)and the plain normal group(99 cases).All cases underwent blood flow detection of middle cerebral artery(MCA)and umbilical artery(UA)before delivery,and cerebral-placental ratio(CPR)was calculated.The incidence of FIUD was compared between high-risk puerperae in plateau area and in plain area.Gestational age,birth weight,cesarean section rate and blood spectrum parameters of MCA and UA were compared between the four groups.The predictive value of color Doppler ultrasound parameters for FIUD was analyzed by receiver operating characteristic(ROC)curves.Results The incidence rates of FIUD and severe FIUD were higher in patients of plateau areas than those in plain areas(36.15%,13.85%vs.23.85%,4.62%,P＜0.05).Compared with the plateau distress group,gestational age and birth weight were increased in the plateau normal group and the plain distress group(P＜0.05).Compared with the plateau distress group,PI,RI,S/D and CPR of MCA were increased,while PI,RI and S/D of UA were decreased in the plateau normal group and the plain distress group(P＜0.05).Results of ROC curve analysis showed that overall performance advantage of S/D of UA was the most obvious in the diagnosis of FIUD in high-risk puerperae in plateau areas.The diagnostic sensitivity of RI of MCA was the highest,and the diagnostic specificity of CPR was the highest(P＜0.05).Conclusion Color Doppler ultrasound has good diagnostic value for FIUD in high-risk puerperae in plateau areas,which can be applied as an effective clinical screening means for FIUD.

Objective To investigate the predictive value of color Doppler ultrasound parameters for fetal growth restriction(FGR)induced by hypertensive disorders of pregnancy in high-altitude re-gions.Methods Pregnant women with gestational hypertension who were treated between July 2020 and June 2022 at the Affiliated Hospital of Qinghai University(with altitude of 2,300 meters,were divided into group A1 with 19 cases and group A2 with 51 cases according to occurrence of FGR),Yushu People's Hospital(with altitude of 3,700 meters,were divided into group B1 with 25 cases and group B2 with 47 cases according to occurrence of FGR),and Civil Aviation Clinical Medical College of Peking University(plain region,control group with 71 cases)were enrolled in this study.All pregnant women in each group underwent fetal color Doppler ultrasound examination of the middle cerebral artery(MCA)and umbilical artery(UA)blood flow parameters,including pulsatility index(PI),resistance index(RI),systolic/diastolic ratio(S/D),peak systolic velocity(PSV),and cere-broplacental ratio(CPR)at 28 weeks of gestation were detected.Multivariate Logistic regression analy-sis was performed to identify independent risk factors for FGR in pregnant women with gestational hy-pertension.Receiver operating characteristic(ROC)curves were plotted to analyze the predictive value of color Doppler parametersfor FGR.Results The UA blood flow parameters(PI,RI,S/D,PSV)of the fetuses in groups A1,A2,B1,and B2 were significantly higher than those in the control group,while the MCA blood flow parameters(PI,RI,S/D,PSV)and CPR were significantly low-er(P＜0.05).Among the five groups,group B1 had the highest UA blood flow parameters(PI,RI,S/D,PSV)and the lowest MCA blood flow parameters(PI,RI,S/D,PSV)and CPR(P＜0.05).Multivariate Logistic regression analysis revealed that high altitude of residence and umbili-cal cord abnormalities were independent risk factors for FGR in pregnant women with gestational hy-pertension(P＜0.05).ROC curve analysis showed that the areas under the curves for the com-bined prediction of FGR in pregnant women with gestational hypertension at altitudes of 2,300 me-ters and 3,700 meters using color Doppler multi-parameters were 0.906 and 0.917,respectively,indicating a significantly higher predictive performance compared to individual parameter(P＜0.05).Conclusion Color Doppler ultrasound parameters of UA and MCA bloodflow during the second trimester of pregnancy demonstrate good predictive value for FGR induced by hypertensive disorders of pregnancy in high-altitude regions at different altitudes,and the predictive performance is even higher when multiple parameters are combined.

Objective To investigate the predictive value of color Doppler ultrasound parameters for fetal growth restriction(FGR)induced by hypertensive disorders of pregnancy in high-altitude re-gions.Methods Pregnant women with gestational hypertension who were treated between July 2020 and June 2022 at the Affiliated Hospital of Qinghai University(with altitude of 2,300 meters,were divided into group A1 with 19 cases and group A2 with 51 cases according to occurrence of FGR),Yushu People's Hospital(with altitude of 3,700 meters,were divided into group B1 with 25 cases and group B2 with 47 cases according to occurrence of FGR),and Civil Aviation Clinical Medical College of Peking University(plain region,control group with 71 cases)were enrolled in this study.All pregnant women in each group underwent fetal color Doppler ultrasound examination of the middle cerebral artery(MCA)and umbilical artery(UA)blood flow parameters,including pulsatility index(PI),resistance index(RI),systolic/diastolic ratio(S/D),peak systolic velocity(PSV),and cere-broplacental ratio(CPR)at 28 weeks of gestation were detected.Multivariate Logistic regression analy-sis was performed to identify independent risk factors for FGR in pregnant women with gestational hy-pertension.Receiver operating characteristic(ROC)curves were plotted to analyze the predictive value of color Doppler parametersfor FGR.Results The UA blood flow parameters(PI,RI,S/D,PSV)of the fetuses in groups A1,A2,B1,and B2 were significantly higher than those in the control group,while the MCA blood flow parameters(PI,RI,S/D,PSV)and CPR were significantly low-er(P＜0.05).Among the five groups,group B1 had the highest UA blood flow parameters(PI,RI,S/D,PSV)and the lowest MCA blood flow parameters(PI,RI,S/D,PSV)and CPR(P＜0.05).Multivariate Logistic regression analysis revealed that high altitude of residence and umbili-cal cord abnormalities were independent risk factors for FGR in pregnant women with gestational hy-pertension(P＜0.05).ROC curve analysis showed that the areas under the curves for the com-bined prediction of FGR in pregnant women with gestational hypertension at altitudes of 2,300 me-ters and 3,700 meters using color Doppler multi-parameters were 0.906 and 0.917,respectively,indicating a significantly higher predictive performance compared to individual parameter(P＜0.05).Conclusion Color Doppler ultrasound parameters of UA and MCA bloodflow during the second trimester of pregnancy demonstrate good predictive value for FGR induced by hypertensive disorders of pregnancy in high-altitude regions at different altitudes,and the predictive performance is even higher when multiple parameters are combined.

Objective:The aim of this study was to explore the associations of muscle size and density with handgrip strength(HGS)and the Timed Up and Go(TUG)test.Methods:Totally 301 participants living in the Xinjiekou community near Beijing Jishuitan Hospital were recruited for CT imaging of the hip and a 1-cm slice of the mid-thigh.The cross-sectional area and density of the gluteus maximus and the mid-thigh muscles were estimated by the Osirix viewer based on CT images.HGS and TUG were also performed in these subjects.Logistic regression analysis was used to evaluate the correlations of muscle density and size with TUG and grip strength.Results:In women, after adjustment for age and BMI, the density of the gluteus maximus was negatively correlated with TUG( P trend=0.0366), while the size of the gluteus maximus and the mid-thigh muscles was not correlated with TUG.In men, the density or size of these muscles was not correlated with TUG.After adjustment for age and BMI, the density of the gluteus maximus was positively correlated with grip strength( P trend=0.0334)and the size of the mid-thigh muscles was also positively correlated with grip strength( P trend=0.0155)in men, but they were not correlated with grip strength in women. Conclusions:There were sex differences in the relationship between muscle size or density and grip strength or timed up and go.The density of the gluteus maximus is associated with muscle strength and physical performance while the size of the mid-thigh muscles is correlated with muscle strength.