BACKGROUND: Osteoporosis is a serious threat to the health and quality of life in the elderly. It is important to establish an ideal experimental animal model to study the etiology and treatment of osteoporosis.OBJECTIVE: To establish a rat model of osteoporosis induced by different dosages of retinoic acid, thus selecting the optimal dosage.METHODS: Eighty female Sprague-Dawley rats were randomly divided into control, low-, middle- and high-dosage groups based on body mass (n=20 per group), The rats in the latter three groups were induced with 80, 100, and 120 mg/(kg?d) retinoic acid via gastric lavage for 14 days.RESULTS AND CONCLUSION: Compared with the control group, the bone mineral density, number of osteoblasts and osteoclasts, and bone microarchitecture in the low-dosage group showed no significant changes, while there were significant decrease in the serum level of calcium and bone mineral density of femur, significant increase in the number of osteoclasts at the femur and significant changes in the femoral microarchitecture in the middle- and high-dosage groups, especially in the middle-dose group. To conclude, 120 mg/(kg?d) retinoic acid via gastric lavage for 14 days can induce a stable osteoporosis model in rats.

Objective: To summarize our preliminary clinical experience of ultrasound-guided needle-perc combined with standard percutaneous nephrolithotomy (PCNL) in the treatment of staghorn stones, and to analyze its safety and efficacy. Methods: The clinical data of 65 patients with staghorn stones treated by ultrasound-guided needle-perc combined with standard PCNL under general anesthesia with the patient in prone position from December 2017 to June 2019 were retrospectively reviewed. A total of 41 males and 24 females were included. The mean age was (53.5+ 8.9) years. The mean body mass index (BMI) was (25.1±2.9) kg/m², and the mean stone diameter was (10.9±3.1) cm. Among them, there were 3 cases with bilateral staghorn stones, 38 cases with complete staghorn calculi, 36 cases with non- or mild preoperative hydronephrosis, 12 cases with previous ipsilateral renal surgery, and 9 cases with solitary kidneys. Ultrasound-guided renal access and tract dilation were used to establish F24 standard channel. Pneumatic combined with ultrasonic lithotripsy with suction system was used to treat staghorn stones under nephroscope. Needle-perc consists of F4.2 needle-like metal sheath connected with a three-way tube. A 0.6 mm diameter video fiber, 200 um holmium laser fiber and liquid perfusion device can be connected through the three-way tube respectively. The residual stone in the parallel calyx after standard PCNL were punctured by needle-perc under ultrasound guidance, and then the holmium laser fiber was used for lithotripsy. Results: In this study, a total of 68 renal units were included. The median operative time was 79.8 minutes, ranging 45-129 minutes. The median decrease of hemoglobin on postoperative day 1 was 10.6 g/L, ranging 0-25.9 g/L. The median length of postoperative hospital stay was 5.5 days, ranging 4-7 days and the median time of tract establishment was 4.8 minutes, ranging 2.5-9.6 minutes. The median number of standard tract established was 1.5, ranging 1-3 and the median number of needle-perc punctured was 1.0, ranging 1-3. The total complication rate was 10.3% (7 cases), including 5 cases of Clavien grade Ⅰ, 2 cases of postoperative fever, 3 cases of analgesic use. There were 2 cases of Clavien grade Ⅱ. All of them were blood transfusion. The initial stone free rate was 79.4%(54/68). Of the 14 patients with residual stones, 9 patients underwent second-stage operation, 7 patients were stone free, and the final stone free rate was 89.7%(61/68). Conclusions Ultrasound-guided needle-perc combined with standard PCNL is safe and effective in the treatment of staghorn stone.

Objective To establish a loop-mediated isothermal amplification method for detection of Campylobacter jejuni.Methods Six sets of primers were designed to recognize Campylobacter jejuni specific gene hipO.One was selected as the optimal primer and its specificity and sensitivity to Campylobacter jejuni were evaluated by LAMP reaction in 60 minutes at 62℃.Results The results recorded by the turbidity meter showed that the sensitivity of LAMP with a detection limit of 6.97×102 copies/μl was ten times that of PCR.Conclusion LAMP is a potential and valuable method of detection of Campylobacter jejuni due to its rapidity,simplicity,low cost and accuracy.It is especially suitable for grass-roots medical units.

Objective To explore the safety and efficacy of fusion imaging technique and traditional ultrasound guidance in percutaneous nephrolithotomy,and to compare the difference of two methods for PCNL.Methods Patients with renal calculus,who underwent percutaneous nephrolithotomy from January 2016 to August 2016,were enrolled in the study.The patients were randomly divided into two groups by SAS software.The control group was treated with traditional ultrasound guided puncture technique (Ultrasound group).Experimental group was treated with fusion imaging method (CT-US group).Preoperative patient CT image data was uploaded to the image fusion ultrasound machine for data synchronization.Both groups used the same way to establish a standard channel (F24).Lithoclast system from EMS was used to remove stones.Intraoperative parameters (time to define the target calyx,access establishment time,operative duration) and postoperative perioperative data (estimated blood loss,stone-free rate,severe complications) were compared between the two groups.Results 65 cases of patients were enrolled into the study.There was no significant difference in age (P =0.72),body mass index (P =0.78),stone size (P =0.53) and so on.Compared with the control group,the time duration to define the target calyx in CT-US group is significantly decreased in experiment group(50.4 ± 18.1) s vs.(82.1 ± 37.7) s,(P =0.02).The time to establish the access and fulfill the procedure shows no significant difference between the two groups,respectvely(P =0.45,0.61).Also,significant differences can be found in the hemoglobin loss during and after the surgery(1.1 ± 0.5) g/L vs.(1.4 ± 0.4) g/L (P =0.04).The difference in severe complications (Clavien Ⅲ and above),stone-free rate (P =0.60) and transfusion rate (P =1.00) was not significant.Conclusions Our primary study shows CT-altrasound image fusion guide PCNL is a safe and reliable technology.The time duration to define the target calyx was decreased compared with traditional US guidance method.The target calyx chosen was more accurate,with lower blood loss during the perioperative period.

Objective To describe and introduce the initial clinical application of a novel instrument needle-perc for percutaneous nephrolithotomy (PCNL) in upper urinary tract stones.Methods 24 patients with upper urinary stone treated by PCNL were collected retrospectively between August 2017 and January 2018.Sixteen patients were male and 8 were female.Average age was 41.2 years,ranging 26-65 years.Eight cases had upper pole stones,6 cases had pelvic stones,8 cases had lower pole stones and 4 cases had the stone in UPJ.The mean calculus size was 1.2 cm,ranging 0.5-1.4 cm.All patients were punctured under total ultrasound with needle-perc.Six cases had upper calyceal puncture,10 cases had middle calyceal puncture and 8 cases had lower calyceal puncture.The needle-shaped nephroscope consists of a puncture sheath and a needle handle.The puncture sheath is a hollow metal sheath with an outer diameter of F4.2,an inner diameter of F3.6,and a length of 15 cm.The tip of the sheath is beveled to facilitate puncture.The outer end of sheath is connected to the needle handle through a screw interface.And the three interfaces of the three-way tube can be respectively connected with a liquid irrigation device,a video optical fiber and a 200 μm holmium laser fiber.The needle-perc integrated image system,the irrigation system,and the nephroscope channel are integrated.The tissue passing through the needle can be simultaneously observed through video optical fiber during puncturing.After the tip of the sheath is inserted into the target calyx,the holmium laser fiber is connected for fragmenting or dusting.Results Needle-perc was successful in 22 cases,2 patients were converted to larger tract(F16).The mean opeartive time was 49.2 min,ranging 22-75 min and the mean hemoglobin loss was 5.2 g/L,ranging 0-13.8 g/L.Mean postoperative hospital stay was 3 days,ranging 1 to 6 days.No Double-J stents or nephrostomy tube was placed in the 22 patients.Complications (Clavien Ⅱ) occurred in 4 cases,including fever in 2 cases and renal colic in 2 cases.Plain film of KUB or CT scan was done and stone free rate at 1 month was 90.9％ (20/22),2 patients needed ESWL to remove the residual stones.Conclusions Needle-perc is efficient and safe for small renal stones (size ＜ 1.5 cm) from our initial experience,with high stone-free rate and low complication rate in early follow-up.

Objective To investigate the feasibility of tract dilation monitored by ultrasound in percutaneous nephrolithotomy (PCNL),and the risk factors for its failure.Methods A retrospective study was conducted on patients underwent PCNL with only one access (F24) using balloon dilator and sequential dilators (Amplatz and telescopic metal dilators) from December 2014 to December 2018 in Beijing Tsinghua Changgung Hospital.A total of 231 patients (130 males and 101 females) underwent ultrasound-guided PCNL with a mean age of (52.3 ± 9.8) years were included in our study.Mean BMI was (25.8 ± 3.1) kg/m2.Mean size of stone was (3.9 ± 1.1)cm,51.1％ (118/231) of which were staghorn stones.Under ultrasound guidance,after puncture of the target calyx,the balloon dilator was advanced through the guide wire,and inflated to establish the F24 standard renal access.Patients' clinical parameters such as age,gender,BMI,stone diameter,history of open nephrolithotomy were collected.Risk factors for the failure of ultrasound guided balloon dilation were analyzed by logistic regression analysis.Results Tract dilation succeed in 89.2 ％ cases (206 succeed,25 failed) at first attempt.Median tract dilation time was 4.2 min (2.2-8.0 min).Mean operation time was 85.5 min(45.0-120.0 min).Median hemoglobin drop at the first postoperative day was 16.0 g/L (5.0-25.8 g/L).The total rate of complication was 9.1％ (21 cases),including 18 cases Clavien Ⅰ and 3 cases Clavien Ⅱ.The stone free rate was 89.6％ (207/231).Logistic regression analysis revealed that lower pole access (P =0.014) was a risk factor for the failure of access establishment,while the presence of hydronephrosis of target calyx (P ＜ 0.001) would significantly increase the success rate.Conclusions Tract dilation using balloon catheter can be safely monitored by ultrasound with high success rate and low complication rate.Lower pole puncture will make tract establishment difficulty.Patients with a hydronephrotic target calyx are more suitable for this procedure.

The community structure and diversity of the gut microbiota are associated with human diseases. However, the analysis of different community structure might be influenced by experimental approaches such as the quality of DNA extraction. Therefore, evaluating the efficiency of different DNA extraction methods for specific intestinal species is a guideline for obtaining a comprehensive human gut microbial profile, which may assist the in-depth investigation into the structure of the gut microbial community. The aim of this study was to perform a comparative analysis of five different DNA extraction methods. With the aid of qPCR, the efficiency of five DNA extraction kits was evaluated in terms of the purity of the extracted DNA, the DNA concentration, and the abundance of genomic DNA extracted from specific intestinal species. The results showed that the kit Q gave the best extraction results, especially for Gram-positive bacteria such as Lactobacillus and Bifidobacterium. The average DNA concentration of the N kit was lower than that of the Q kit, but there was no significant difference between the two in terms of the purity. Compared to the other three commercial kits (M, PSP, TG), the efficiency of the N kit in extracting the genomic DNA of the specified microorganisms were the least different from those of the Q kit. In contrast, the DNA extracted by the M kit was of higher quality but of lower concentration, and was not very efficient for Gram-positive bacteria. The DNA extracted by the TG and PSP kits was inferior to the other validated kits in terms of the concentration, quality and bacterial abundance. These results provide a basis for the selection of genomic DNA extraction methods in microecological research experiments.
DNA/genetics* ; DNA, Bacterial/genetics* ; Feces/microbiology* ; Humans ; Microbiota/genetics* ; RNA, Ribosomal, 16S/genetics*

OBJECTIVE： To investigate the effects and its mechanism of calcium phosphate bone cement （CPC） loading total flavonoids of Davallia mariesii on osteogenic differentiation of induced membrane in rats. METHODS： Drug-loading CPC and drug-loading polymethyl methacrylate （PMMA） cement were prepared with the contents of Qianggu capsules （total flavonoids of D. mariesii as active ingredient） using CPC and PMMA cement as carrier. Totally 64 male SD rats were randomly divided into drug-loading CPC group， drug-loading PMMA cement group， no-drug CPC group， no-drug PMMA cement group， with 16 rats in each group. The femur of rats was separated and osteotomized to prepare bone defect model， and then the corresponding bone cement was implanted. Four weeks after modeling， the induced membranes of rats were cut and protected. Bone cement was taken out and autogenous cancellous bone was implanted. At the 4th week after modeling， X-ray photographs were taken on the hind limb bones of rats. At the 4th week after modeling and 6th week after bone grafting， induced membranes and new bone were taken from the bone defect area of rats respectively. HE staining was used to observe the morphology of induced membrane， and the width of bone rabecular and the number of osteoblasts of new bone tissue were measured. Immunohistochemistry was used to detect the protein expression of BMP-2 and VEGF in induced membrane. Western blotting assay was used to detect the protein expression of Smad1， Smad4 and Smad7 in new bone. RESULTS： Compared with other 3 groups， the degradation of bone cement in drug-loading CPC group was more obvious in the bone defect areas， which showed that the formation of induced membrane was observed and the bone defect areas were smaller； capillary endothelial cells were abundant and orderly arranged in the induced membranes， and the width of bone trabeculae and the number of osteoblasts in the new bone tissue increased significantly （P＜0.05）； the protein expression of BMP-2 and VEGF in the induced membrane， the protein expression of Smad1， Smad4 and Smad7 in new bone were increased significantly （P＜0.05）. CONCLUSIONS： CPC loading total flavonoids of D. mariesii promotes the formation of induced membrane osteoblast in bone defect model rats， which may be associated with regulating osteoblast differentiation by activating BMP-2/Smad pathway； at the same time， it can promote bone healing by promoting the differentiation of vascular endothelial cells， accelerating the formation of capillary network and increasing the expression of vascular endothelial cells.