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: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.