BACKGROUND: Studies on the reparation of peripheral nervous system are not only a key focus in medical research, but also a major topic for biologists, biochemical engineers and materialogy specialists. OBJECTIVE: To investigate the individual difference of ideal muscle bridging neurologic defect configuration on nerve regeneration. DESIGN, TIME AND SETTING: The control experiment was performed at the Shenyang Medical College from June 2004 to September 2005. MATERIALS: Ten common dogs weighing 20-30 kg were used in this study. METHODS: After intravenous anesthesia, muscle strips in the caudal right sartorius and middle musculus flexor digitorum superficialis of dogs were sliced into two segments. One was observed by dissection under a stereoscope. Another received Haematoxylin & Eosin (HE) Staining and transverse area of muscle fiber of distal and proximal ends was analyzed by image analysis. The same muscle strip was sutured at 2 cm neurologic defect region of autologous left and right limbs. Number of medullated nerve fibers was measured after osmic acid staining. MAIN OUTCOME MEASURES: Morphological difference of muscle bridge, transverse area of muscle fiber of distal and proximal ends, and number of medullated nerve fibers at bridging femoral nerve defect of left and right limbs. RESULTS: The muscle fiber in sartorius paralleled the longitudinal axis of muscle strip. The angle between muscle fiber in musculus flexor digitorum superficialis and the longitudinal axis of muscle strip was big. 80% muscle fiber in sartorius was equa1 to the length of the muscle bridge. Muscle fiber in the musculus flexor digitorum superficialis was shorter than the length of muscle strip. Muscle fiber in the musculus flexor digitorum superficialis was thick, whereas muscle fiber in sartorius was thin. There were significantly differences in transverse area of muscle fiber in the two kinds of muscle bridges (P

BACKGROUND: Studies concerning muscle-derived stem cell transplantation mainly focused on treatment of muscular dystrophy. There are no studies on muscle-derived stem cells for treatment of denervated amyotrophy combined therapy. OBJECTIVE: To explore effects of muscle-derived stem cell transplantation on denervated gastrocnemius atrophy. DESIGN, TIME AND SETTING: The randomized controlled animal study was performed at the Shenyang Medical College from February 2007 to July 2008. MATERIALS: A total of 19 adult healthy male Wistar rats were supplied by Animal Experimental Center, Shenyang Medical College. METHODS: Triceps brachii was sterilely collected from 3 rats, and muscle-derived stem cells were isolated in vitro, and purified by adherence method. The tibial nerve of right posterior limb was cut in remaining 16 rats to establish animal models of denervated gastrocnemius. In the cell transplantation group, 0.2 mL DAPI-labeled muscle-derived stem cell suspension was infused into the denervated gastrocnemius. The same volume of saline was injected into the model control group, for 4 weeks. MAIN OUTCOME MEASURES: Computer biological signal collection processing system was used to measure recovery rate of threshold intensity of gastrocnemius and the optimal intensity recovery rate. Electronic balance was utilized to calculate residual rate of wet weight. Image analysis system was used to measure residual rate of cross section area. RESULTS: Compared with the model control group, the recovery rate of threshold intensity of denervated gastrocnemius and the optimal intensity recovery rate were significantly lower in the cell transplantation group (P

Objective To investigate the membrane topology of transient receptor potential(TRP)channel. Methods Glycosylation method was used to investigate the membrane integrations of each hydrophobic segment of canonical TRP(TRPC5). Results In TRPC5 channel,S4?S8 segments were integrated into membrane with Ncyt/Cexo and Nexo/Ccyt orientations sequentially ,and C?terminus was intracellular. S1?S3 segments were integrated into membrane with two possible types. One was that S1 and S3 were integrated into membrane,whereas S2 was left out of the membrane on the cytosolic side;and the other was a mixed type that S1 and S3 were exposed to cytoplasm respectively. Both of them,the N?termi?nus was intracellular. Conclusion S4?S8 segments of TRPC5 are transmembrane segments. The integrations of S1?S3 segments into membrane need to be further investigated.

The exam under open and close condition is a new mode which is different from traditional close-exam and entire open-exam.It indicates that new exam mode not only conquers limitation of simplex close-exam,but also boosts forwardly study of students and promotes the didactical reform completely.

BACKGROUND:Skin transplantation is regarded as the most effective therapy for large-area skin defects, which is limited by donor sources and immune rejection. Therefore, it is extremely accelerate the construction of the dermis in skin tissue engineering.
OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane on the repair of ful-thickness skin defects.
METHODS:Bone marrow mesenchymal stem cels were isolated from 15 New Zealand rabbits, and then cultured, amplified, subcultured and purified. Three ful-thickness skin defects were made on the back of every rabbit, and randomly treated with bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane as experimental group, bone marrow mesenchymal stem cels/calcium alginate gel as control 1 group, and calcium alginate gel as control 2 group. The wounds were al covered with amniotic membrane. After 7, 14, 21 days, new wound tissues were taken for hematoxylin-eosin staining, immunohistochemistry staining and image analysis.
RESULTS AND CONCLUSION: Dermis tissues in the experimental group were obviously thicker than those in control 1 and control 2 groups; there were more fibroblasts, vessels and colagen fibers in the experimental group. Especialy at 14 and 21 days after operation, epidermal hyperplasia was faster with a larger coverage area in the experimental group, and at 21 days, the new epidermal tissues mainly exhibited multi-layered structure, which was superior to the control 1 and 2 groups. It folows that the combination of bone marrow mesenchymal stem cels/calcium alginate gel, basic fibroblast growth factor and degradation membrane for skin defects can accelerate the repair and regeneration of the dermis, and thus promote the epidermis regeneration and reconstruction.

Objective:To study the expression of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in oral leukoplakia for clarifying the role of oxidative DNA damage in the development of oral leukoplakia. Methods:Immunofluorescence labeling method was used to examine the expression of 8-oxodG,a marker of oxidative DNA damage,and the expression of tumor suppressor gene, P53 protein in oral epithelium of normal oral mucosa and biopsy specimens of leukoplakia. Results:In specimens of oral leukoplakia, HE staining showed infiltration of inflammatory cells, hyperkeratosis and epithelial dysplasia. Immunofluorescence labeling study demonstrated that the accumulation of 8-oxodG apparently increased in the oral epithelium of patients with leukoplakia,whereas little or no immunoreactivity was observed in normal oral mucosa. Expression of P53 protein was also observed in oral epithelium of patients with oral leukoplakia. The immunoreactivity of 8-oxodG and P53 was stronger in patients with oral leukoplakia than that in normal oral mucosa (P<0.01) . Moreover,the immunoreactivity increased with the development of disease (r=0.773, P<0.01) . Conclusions:The oxidative DNA damage contributes to the development of oral leukoplakia. 8-oxodG may be a risk predictive marker for oral leukoplakia.

Objective:To explore the clinicopathologic features and risk factors of IgA nephropathy (IgAN) after kidney transplantation.Methods:A retrospective analysis was conducted for biopsy-confirmed IgAN patients after transplantation from January 2016 to September 2019. The clinicopathological characteristics and risk factors of IgAN after expanded criteria donor (ECD) donor for kidney transplantation were examined by statistical analysis of general clinical data and Oxford classification during and after transplantation.Results:The diagnostic rate of IgAN after transplantation was around 12.77%. The clinical symptoms occurred at an average of 22.5 months after transplantation. 66.67%(12/18) patients were in stage 3-4 chronic kidney disease (CKD). There were microscopic hematuria (76.92%) and varying degrees of proteinuria (88.89%). The scores of pathological parameters were as follows: 78% patients with mesangial cell proliferation (M1), 17% with endothelial cell proliferation (E1), 65% with segmental sclerosis (S1), 39% with moderate-to-severe tubules atrophy/interstitial fibrosis (T1/T2) and 17% with crescent formation (C1) respectively. Tubuloatrophy/interstitial fibrosis was associated with estimated glomerular filtration rate (eGFR) at biopsy ( P<0.05). Group of urine protein quantification >1g/d and group of <1g/d group had statistically significant differences in segmental sclerosis and adhesion lesion ( P<0.05). Conclusions:Oxford classification is valuable in the clinical evaluations of allograft IgAN: Tubular atrophy/interstitial fibrosis is associated with a decline of glomerular filtration. And segmental sclerosis and adhesion lesion are correlated with the severity of proteinuria.

Objective To explore the correlation between pre-transplantation donor kidney biopsy and short-term renal function after transplantation.Methods This study include 240 kidney transplantation of donation after cardiac death (DCD) from July 2016 to April 2018.Banff's score of donor kidney biopsy was employed for estimating kidney status.Results No significant correlation existed between rate of glomerulosclerosis and delayed graft function (DGF) (P =0.815).The rate of glomerulosclerosis was significantly correlated with 1-week estimated glomerular filtration rate (eGFR) and discharge eGFR (P＜0.05).Based upon the glomerulosclerosis rate,the patients were divided into two groups ＜ 20％ (n =220) and ≥20％ (n =20),there was no significant inter-group difference in DGF,1-week eGFR or discharge eGFR (P＞0.05).Arterial fibrosis was significantly positively correlated with DGF and negatively with 1-week eGFR and discharge eGFR (P＜0.05).Statistically significant inter-group differences existed in 1-week eGFR and discharge eGFR that arterial fibrosis scores ＜ 2 (n =19) and ≥2 (n =41) (P＜0.05).Arteriolar hyalinosis score was negatively correlated with 1-week eGFR and discharge eGFR (P＜0.05).Based upon arteriolar hyalinosis scores,they were divided into two groups ＜ 2 (n =193) and ≥2 (n =47).There were significant inter-group differences in DGF,1-week eGFR and discharge eGFR (P＜0.05).Remuzzi scores were negatively correlated with 1-week eGFR and discharge eGFR (P＜0.05).Interstitial fibrosis was significantly positively correlated with DGF (P＜0.05) and negatively with 1-week eGFR and discharge eGFR (P＜0.05).Conclusions Donor kidney glomerulosclerosis rate affects short-term renal function of recipients after transplantation.However,using 20％ as a threshold value is limited in clinical practice.Arterial intimal fibrosis and arteriolar hyalinosis are important factors affecting short-term eGFR.Recipient kidneys with Remuzzi score ＞ 4 had poor renal function after transplantation.Interstitial fibrosis score may be used as a predictor of postoperative DGF and shortterm renal function recovery.It is expected to be discussed more extensively in literature.

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (M^pro) and papain like protease (PL^pro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851M^pro inhibitors and 205 PL^pro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both M^pro and PL^pro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of M^pro inhibitors and over 20% of PL^pro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 M^pro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.
Humans ; Antiviral Agents/chemistry* ; COVID-19 ; COVID-19 Drug Treatment ; High-Throughput Screening Assays ; Molecular Docking Simulation ; Protease Inhibitors/chemistry* ; SARS-CoV-2/enzymology* ; Viral Nonstructural Proteins