Objective To investigate the effect of Chinese medicine Louxie mixture on vascular reactivity in atherosclerosis rats. Methods Forty male rats were randomly divided into four groups: the control group (A group, n＝10) was fed with normal diet; the model group (B group, n＝10), atorvastatin treated group (C group, n＝10 and Louxie mixture group (D group, n＝10) were fed with high fat/cholesterol diet. Atorvastatin 10 mg/kg·d-1 was administered to C group and Louxie mixture to D group for 10 weeks by gavages. Serum endothelin-1 (ET-1), nitric oxide (NO) and nitric oxide syntheses (NOS) were observed in different groups before and after the treatment. Vascular reactivity of aortic rings was measured by both the sodium nitroprusside(SNP)-induced endothelium-independent relaxation (NEDR) and the acetylcholine (Ach)-induced endothelium-dependent relaxation (EDR) in different groups. Results After treatment, the (19.03±1.72)μmol/l; NOS (24.78±0.25)U/ml vs (15.36±0.24U/ml), P＜0.01], while the level of ET-1in B levels of NO and NOS in B group were significantly lower than those in A group [NO(35.73±3.72)μmol/l vs group was higher than that in A group [(34.58±4.00) pg/ml vs (117.58±5.34)pg/ml,P＜0.01]. The levels of NO and NOS were significantly increased and the level of ET-1 was decreased in C and D groups after the treatment [NO(C: 31.30±1.96 umol/l;D: 32.85±3.70 umol/l); NOS (C: 21.96±1.07 U/ml ; D: 19.78± 1.20U/ml ); ET (C:58.26±5.14 pg/ml; D:59.30±5.73 pg/ml), P＜0.01]. The activities of NEDR were similar in four groups[SNP Emax (A: 97.33±1.31; B: 98.24±1.04;C: 97.52±1.09; D: 97.91±1.59)%, P＞0.05], but the level of EDR in the B group (P＜0.01) was the lowest among four groups [Ach Emax (A: 72.65±3.31; B: 32.68±2.39;C: 61.63±2.07; D: 57.58±2.43)%, P＜0.01]. Conclusion Chinese medicine Louxie mixture can protect vascular function in atherosclerosis rats.

Objective:To study the level of CT dose to paediatric patients in Tianjin, and to provide basic data for establishing the diagnostic reference levels for paediatric patients from CT examinations in Tianjin.Methods:In 2022, a general survey was carried out of the CT doses to the head, chest, abdomen and pelvis of the scanned paediatric patients in two tertiary pediatric hospitals and seven tertiary general hospitals in Tianjin. The scanned pediatric patients were divided into four age groups in terms of the age of -1, -5, -10 and -15 years, and 20 patients were investigated in each age group in each hospital. The basic information were collected on the scanned patients, CT scanning parameters, volume CT dose index (CTDI vol), dose length product (DLP), and the differences in CTDI vol and DLP on the same site among different age groups and different types of hospitals were analyzed. Results:There were significant differences in CTDI vol and DLP between different age groups at the same site (head, chest, abdominal and pelvic, CTDI vol:χ2=296.51, 193.82, 291.72, P<0.001; DLP: χ2=291.22, 263.63, 344.97, P<0.001). There were significant differences in CTDI vol and DLP among different types of hospitals on the same site (head, chest, abdominal and pelvic, CTDI vol:Z=-13.13, -7.57, -15.27, P<0.001; DLP: Z=-9.07, -6.15, -11.57, P < 0.001). Conclusions:The 75 th percentile values of CTDI vol and DLP for pediatric head, chest, abdomen and pelvis CT scanning in tertiary hospitals in Tianjin are at a good level, and the dose on some examination sites are relatively high. Further optimization of pediatric CT scanning procedures is necessary.