Objective To investigate the therapeutic effects of mesenchymal stem cells (MSCs) on N-methyl-N-nitrosourea (MNU)-induced retinal degeneration in C57BL mice.Methods Different doses of MNU (30 mg · kg-1,45 mg · kg-1,60 mg · kg-1,75 mg · kg-1 and 90 mg · kg-1) were injected to C57BL mice for 7 days.Then electroretinogram (ERG) detection and HE staining were performed to examine retinal electrophysiological function and morphological changes on day 1,day 3 and day 7 after MNU treatment,respectively.Then we could explore the optimum condition to establish stable animal model of retinitis pigmentosa.MSCs were transplanted to C57BL mice by intravitreal or tail intravenous injection.Then ERG detection and HE staining were performed to evaluate the effect of MSCs on retinitis pigmentosa induced by MNU.Results When compared with control group,30 mg · kg-1 and 45 mg · kg-1 MNU could cause mild retinal damage in morphology and function in mice;while 60 mg · kg-1 and above dose of MNU induced serious retinal damage,leading to decreased ERG amplitude of the retina (all P ＜ 0.001) and outer nuclear layer (ONL) thickness (all P ＜ 0.001).On day 1 and day 3 after single dose of 60 mg · kg-1 MNU injection,ERG amplitude of the retina was decreased,and outer nuclear layer thickness became thin;while the retinal damage was serious badly in morphological structure on day 7,with the ERG amplitude extinguished (all P ＜ 0.001),ONL thickness thin (all P ＜ 0.001) and internal and external nuclear layer fusion.When compared with MNU alone treatment group,following injection of 60 mg · kg-1 MNU for 1 day MSCs were transplanted to C57BL mice by intravitreal or tail intravenous injection,and the amplitude of ERG and retinal ONL thickness were increased on day 7 after MSCs transplantation (all P ＜ 0.001).Conclusion MSCs transplantation has a certain therapeutic effect on MNU-induced retinitis pigmentosa in C57BL mice.

Objective To evaluate the clinical effects and complications in treating colonic polyps between endoscopic submucosal dissection and laparoscopy.Methods 69 colonic polyps patients diagnosed by colonoscopy with the basal body diameter of the colonic polyp >2.0 cm were enrolled in this study. All the patients were divided into study group (n = 41) and control group (n = 28) according to patients' decision, and then treated with ESD and laparoscopic surgery separately. After treatment, all the patients were followed up and repeated colonoscopy after 6 months. Clinical data were recorded and analyzed at the end of the research.Results Patients were successfully operated in both groups. 1 case in each group was diagnosed of malignant tumor and needed further treatment. The average operation time in study group and the control group was (85.00± 36.50) min and (110.00 ± 45.70) min (P < 0.05), length of hospital stay of the two groups were (10.69 ± 3.09) d and (11.61 ± 6.41) d (P < 0.05), and average cost of hospitalization of the two groups were (15.7 ± 2.7) ten thousand RMB and (30.6 ± 5.9) ten thousand RMB (P < 0.05). Percentage of complications in the study group was 2.43% comparing to 14.29% of control group(P < 0.05). 1 case in the study group complicated with enteron hemorrhage. Complications in the control group was 2 cases of ileus, 1 case of infection, 1 case of intestinal fistula. No recurrence was found in the two groups after 6 months in the repeat colonoscopy.Conclusion Both of the two treatments are effective for patients with wide base colonic polyps, but malignant tumor must be cautioned when treating with wide base colonic polyps. Endoscopic submucosal dissection requires proficient skill while with less impairment and cost.

Objective To observe the effect of mPFC neuron synaptic plasticity changes in the formation of morphine related reward memory.Methods 40 SD rats were administered morphine (10 mg/kg,ip) or saline (2 ml/kg,ip)and sacrificed 0,2,4 and 8 h after the treatment.The temporal profile of activity-regulated cytoskeleton-associated protein (Arc/Arg 3.1) expression in medial prefrontal cortex (mPFC) was analyzed.Another 40 rats receiving a single injection of morphine at different doses (0,5,10 or 20 mg/kg),and rats were sacrificed by decapitation 2 h later.In mPFC,changes of Arc/Arg 3.1 protein was analyzed by Western Blot,Arc/Arg 3.1 positive cells was detected by immunohistochemistry (IHC),and number of spines were analyzed by Golgi-cox method.In the second experiment,CPP model was established by 5 mg/kg morphine for 8 days.Arc/Arg 3.1 antisense oligodeoxynucleotide (AS) or the control (CS) was microinjected into mPFC 15 minutes before each morphine injection,then CPP score was evaluated.Results Compared with saline groups,Arc/Arg 3.1 protein,Arc/Arg 3.1 positive cells,number of spines ((1.01±0.04) vs (1.58±0.18),P＜0.01 ; (42.80±7.63) vs (74.47±8.02),P＜0.01 ;(17.27±5.64) vs (39.47±7.56),P＜0.01) were significantly increased 2 hours after morphine administration.All three doses of morphine (5,10 and 20 mg/kg) increased Arc/Arg 3.1 protein expression in the mPFC,and there were no dose-dependent effects.In CPP experiments,compared with microinjection of Arc/Arg 3.1 CS (0.74±0.02),Arc/Arg 3.1 AS microinjection significantly decreased the CPP score (0.51±0.01) in morphine group (P＜0.01).Conclusion It is enough to increase Arc/Arg 3.1 protein content and synaptic plasticity in mPFC by 10 mg/kg,and the changes implied in formation of morphine relative reward memory.

Objective To evaluate the clinical value of full-field digital mammography three-dimensional (3D) positioning system for localization and excision of nonpalpable breast lesions.Methods 106 patients with nonpalpable breast lesions and underwent preoperative localization were analyzed retrospectively.They underwent wire-localization operation guided by mammography 3D positioning system (GE Senogrphe DS).The depth of wire insertion was calculated manually and automatically.Combined with the manual measurement, systematic measurement, skin elasticity and breast parenchyma structure, the positioning wire was placed.Then, the clinical resection was performed according to the wire localization.Results The localization accuracy of mammography 3D positioning system was 100%.11 patients appearedsyncope.With the rest, psychological comfort and fluid infusion, patients recovered quickly.Conclusion Full-field digital mammography 3D positioning system can improve the accuracy of clinical resection of nonpalpable breast lesion.

Objective To investigate the effects and signal transduction pathway of vasonatrin peptide(VNP),a novel man-made natriuretic peptide,on hepatic fibrosis.Methods Mice were injec ted with carbon tetrachloride(CCl4)for 12 weeks,with or without VNP treatment in the last 6 weeks.HE staining and Sirius red staining were performed to evaluate the status of hepatic fibrosis.In vitro after treatment of VNP,and DNA and collagen synthesis of cultured HSC-T6 hepatic stellate cells were assessed by[3H]-thymidine and[3H]proline incorporation,respectively.The signaling pathway involved was identified by radioimmunoassay to detect the levels of intracellular cGMP,and by mimicking experiments using 8-br-cGMP(a membrane-permeable cGMP analog).Blocking experi ments were performed using HS-142-1,an antagonist of guanylyl cyclase-coupled natriuretic peptide receptor(NPR),or KT-5823,the cGMP-dependent protein kinase(PKG)inhibitor.Results VNP markedly alleviated CCl4-induced liver fibrosis in mice.In vitro,HSC-T6 cells demonstrated a dosedependent reduction of DNA and collagen synthesis in the presence of VNP.In addition,VNP significantly increased intracellular levels of cGMP.The effects of VNP were mimicked by 8-br-cGMP,but they were inhibited by HS-142-1,or KT-5823.Conclusion VNP ameliorated liver fibrosis by inhibiting collagen production from hepatic stellate cells via guanylyl cyclase-coupled NPR/cGMP/PKG signal pathway,indicating that VNP might be a new effective agent in the treatment of liver fibrosis.

Objective To explore the clinical application value of core needle biopsy guided by fully digital mammography three-dimensional positioning system in the diagnosis of breast lesions.Methods A retrospective analysis of 21 patients who underwent guided core needle biopsy in a fully digital mammography system was performed.2 1 patients had 2 1 lesions,which included mass (4 cases),suspected calcification (15 cases)and glandular collection (2 cases)based on X-ray examination before biopsy.The needle depth was manually calculated according to the mammogram (0°and 90°),and automatically calculated with the full digital mammography three-dimensional positioning system. The needle depth was adjusted according to the combination of above two values with the patient’s skin elasticity and gland structure. After putting a small incision into the needle with local anesthesia,X-ray radiography was taken to observe the position of the puncture needle, and then the puncture gun was excited to take out the tissue at different positions of the lesion.Finally,X-ray radiography of the tissue was performed.Results 21 patients underwent biopsy with the average operation time of 45 minutes and puncture time of 25 minutes.The needle depth adjustment range was 3－5 mm,using 14G puncture needle and 4－8 pieces of tissue were pierced according to the lesions. X-ray radiographywas performed on the removed tissue strips. For all the cases of suspected calcification,the calcified lesions were found in the removed tissue strips.No serious adverse reactions occurred in 21 patients with lateral position (1 9 cases)and sitting position (2 cases).2 patients with sitting position developed dizziness, nausea,and palpitation,and recovered quickly after rest and psychological comfort.Puncture pathology confirmed 6 cases of breast cancer (1 case of intraductal papillary carcinoma,2 cases of ductal carcinoma in situ,3 cases of invasive breast cancer),and 1 5 cases of benign lesions,with no obvious changes after one year follow-up.Conclusion In the core needle biopsy guided by the fully digital mammography three-dimensional positioning system for breast lesions,the patient should be placed in the lateral position, which can effectively reduce the occurrence of adverse reactions.A 14G puncture needle and ≥4 tissue strips can achieve a higher pos-itive rate.The technology is simple and easy to perform with a high puncture accuracy,and has important application value.

COVID-19/virology* ; China/epidemiology* ; Disease Outbreaks ; Genetic Linkage ; Humans ; Phylogeny ; Polymorphism, Single Nucleotide ; SARS-CoV-2/isolation & purification*