Objective To explore the biocompatibility of nano-hydroxyapatite/polyamide 66 (nHA/PA66) with human bone mesenchymal stem cells (hBMSCs) after osteogenic induction.Methods After hBMSCs were isolated and cultured in vitro,the experiment was conducted in 3 groups.Group A were hBMSCs subjected to no osteogenic induction,group B hBMSCs subjected to osteogenic induction,and group C was the composite of nHA/PA66 with hBMSCs subjected to osteogenic induction.Adhesion of the cells onto the nHA/PA66 in group C was observed by electron microscope scanning.Growth and proliferation of the cells in groups B and C were detected by MTI test at 1,2 and 3 weeks.The ability of osteogenic differentiation of hBMSCs in vitro was analyzed by alkaline phosphatase (ALP) activity and alizarin red staining.The ability of osteogenic differentiation of hBMSCs on nHA/PA66 was tested by ALP activity.Results Electron microscope scanning showed that the cells spread and attached well on the surface of the composite scaffold in group C;the proliferation of the cells in groups B and C showed no significant difference (P ＞ O.05).These suggested that the proliferation of hBMSCs was not affected by nHA/PA66.The number of mineralized nodules in group B was significantly larger than in group A (P ＜ O.05);the ALP activity of the cells in group A was significantly lower than in group B at 6 and 12 days (P ＜ 0.05);no significant differences were observed between groups B and C (P ＞ 0.05).These indicated that the hBMSCs were capable of osteogenic differentiation which was not affected by nHA/PA66.In groups B and C,the ALP activity of the cells at 12 days was significantly higher than at 6 days,indicating the ALP activity increased with increased induction time (P ＜ 0.05).Conclusion nHA/PA66 can be used as a carrier of hBMSCs in bone tissue engineering because hBMSCs can well adhere to,proliferate,and differentiate into bone on nHA/PA66 scaffolds.

Objective To investigate the efficacy and safety of blood purification therapy in the treatment of diuretic resistance in patients with nephrotic edema.Methods 40 cases of primary nephrotic syndrome with diuretic resistance in our hospital were randomly divided into hemodialysis (HD) group and continuous blood purification (CVVH) group and each group were 20 cases.All the patients were given basic treatment (lipid modulation,anticoagulation and glucocorticoid) and the observation time was 4 weeks.The changes of biochemical indexes (24 h urine protein,plasma albumin,serum urea nitrogen and serum creatinine) were observed before and after treatment in two groups.In addition,the complications of four groups were recorded.Results After blood purification treatment,urinary volume of two groups were significantly increased,the quantity of 24 h urinary protein and serum albumin were significantly improved,levels of serum urea nitrogen and serum creatinine were significantly decreased.The differences were statistically significant (P ＜ 0.05 or P ＜ 0.01).Compared with HD group,the urine volume increased more obviously in CVYH group after 2 weeks' treatment (P ＜ 0.05).The same time,24 h urinary protein was reduced and plasma albumin was improved more significantly (P ＜ 0.05),levcls of serum urea nitrogen and serum creatinine were not differ between the two groups (P ＞ 0.05).There was no difference in urine volume and renal function between the two groups (P ＞ 0.05) after 4 weeks' treatment.24 h urinary protein was significantly decreased and serum albumin was significantly higher than HD group (P ＜ 0.05).There were no serious complications in the two groups.Conclusion Blood purification in the treatment of diuretic resistance in patients with nephrotic edema is safe and effective.Continuous blood purification treatment can effectively alleviate nephrotic edema with diuretic resistance,promote the recovcry of renal function and improve the prognosis of kidney disease.

Central precocious puberty (CPP) is an endocrine disease of children due to the early onset of hypothalamic-pituitary-gonadal axis function. This leads to increased secretion of gonadotropin release impulse, causing the development of internal and external genitalia and the presentation of secondary sex characteristics. Studies have found that the onset of CPP in children may be related to vitamin D deficiency. Vitamin D, affected by sunlight duration, acts on neurons and neurotransmitters in the hypothalamic-pituitary-gonadal axis, promotes obesity and affects the expression level of insulin-like growth factor-1, which are four factors involved in the occurrence and development of CPP. The overall effect of vitamin D combined with gonadotropin-releasing hormone analogues on CPP is significant. This article reviews the correlation between vitamin D deficiency and CPP, as well as the possible mechanism of action, in order to provide some theoretical basis for researchers.

Objective:To compare the clinical effects of hip arthroplasty through direct anterior approach (DAA) in lateral decubitus in the treatment of hip osteoarthritis caused by Kaschin-Beck disease and congenital acetabular dysplasia.Methods:The prospective study method was used to select the patients who needed hip arthroplasty in the Fourth Department of Orthopedics, the Second Affiliated Hospital of Harbin Medical University from January 2015 to December 2019. All of them were operated with lateral decubitus DAA. According to the inclusion criteria, they were divided into Kacshin-Beck disease hip osteoarthritis group (group A) and congenital acetabular dysplasia hip osteoarthritis group (group B). Hip Harris score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, visual analogue scale (VAS) score were conducted, and hip abduction angle and flexion angle were measured before surgery, 3, 14 days and 1, 3, and 12 months after surgery.Results:Nineteen and twenty-two patients were included in group A and group B, respectively. All patients successfully completed the surgery. There was no significant difference in Harris score between the two groups before surgery, 3, 14 days, and 1, 12 months after surgery ( P > 0.05). There were no significant differences in WOMAC score, VAS score, hip abduction angle and hip flexion angle between the two groups before surgery and each time point after surgery ( P > 0.05). In the same group, there were significant differences in Harris score, WOMAC score, VAS score, hip abduction angle and hip flexion angle at different time points ( P < 0.001). All postoperative indicators were significantly improved compared with those before surgery. Conclusions:There is no significant difference in the clinical effects of hip arthroplasty through lateral decubitus DAA in the treatment of hip osteoarthritis caused by Kaschin-Beck disease and congenital acetabular dysplasia. This surgical method has good therapeutic effect on both types of hip osteoarthritis.

ObjectiveTo determine the epidemiological characteristics of COVID-19 in Shaanxi Province. MethodsEpidemiological analysis was conducted on the confirmed cases of COVID-19 （n=245） from January 23rd， 2020 through February 21st， 2020 based on the official data announced by Shaanxi Province. The effects of local population migration， prevention and control measures on the epidemic were explored. ResultsAs of February 21st， 2020， a total of 245 COVID-19 cases had been notified in Shaanxi Province， with a cumulative incidence rate of 0.63 per 100 000， of which imported cases accounted for 47.34%. The high incidence was observed between January 31st and February 5th. Xi’an had the largest number of COVID-19 cases， followed by Ankang， Hanzhong and Xianyang， totally accounting for 81.20% of the cases in the province. In terms of social factors， daily morbidity was positively correlated with Baidu migration scale index 14 days before. On January 25th， the provincial health emergency response was launched， and on January 31st， it was further upgraded for quarantine. On February 20th， the provincial prevention and control system was implemented by classified areas. There were no emerging local cases after February 21st and no confirmed cases for 28th consecutive days as of March 19th. Local cases and close contacts were cleared to zero on March 27th. ConclusionThe COVID-19 epidemic in Shaanxi Province is mainly concentrated in Guanzhong area and southern Shaanxi， with a widespread pattern in all cities. The prevention and control measures have effectively contained the epidemic， with a declining incidence. However， quarantine of suspected cases and close contacts remains crucial for routine prevention and control strategy.