Objective To investigate the effects of serum cobalt ion concentration on the liver, kidney and heart in mice. Methods Forty 4-week-old male ICR mice were randomly divided into four groups saline were given by intraperitoneal injection once per day for 3 weeks. The body weights of the mice were recorded every 3 days to ensure the correct doses of cobalt chloride. Blood samples for testing were taken at day 4, week 1, week 2 and week 3. Serum cobalt ion concentrations were measured in all samples whereas other serum biochemical variables, including aspartate aminotransferase (AST), alanine transaminase(ALT),blood urea nitrogen (BUN), creatinine (Cr), and creatine kinase (CK) were evaluated at week 1, 2 and 3. After killing the mice at week 3, the heart, liver and kidney were collected for pathological evaluation. Results Serum cobalt ion concentration was different between the groups. High-dose cobalt chloride significantly increased AST, ALT and CK concentrations, the concentrations increasing in parallel with treatment duration.Pathological evaluation showed that high-dose cobalt chloride had toxic effects on the heart and liver, however no significant effect was apparent in the kidney. Conclusion High-dose cobalt ion concentration in serum has toxic effects on the heart and liver, but no significant effect on the kidney in mice.

BACKGROUND:Chitosan biological materials can induce bone marrow mesenchymal stem cells to differentiate toward neurons. As a derivative of chitosan, carboxymethyl chitosan has a series of excelent properties. However, whether carboxymethyl chitosan can induce the neuronal differentiation of bone marrow mesenchymal stem cells remains unclear.OBJECTIVE:To investigate the effect of carboxymethyl chitosan thermosensitive hydrogel on the differentiation of bone marrow mesenchymal stem cells into neurons and the possible mechanism.METHODS:Passage 3 bone marrow mesenchymal stem cells from rats were selected and cultured in carboxymethyl chitosan thermosensitive hydrogel extracts in different concentrations (0, 50, 100, 150, 200, 500 g/L). Control cells were cultured in culture medium with no addition of carboxymethyl chitosan thermosensitive hydrogel extracts. MTT assay was performed to investigate the effects of different concentrations of carboxymethyl chitosan thermosensitive hydrogel extracts on bone marrow mesenchymal stem cell proliferation. Western blot assay was used to explore the effect of 150 g/L carboxymethyl chitosan thermosensitive hydrogel extracts on the expression of neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, β3-tubulin, Notch1 and Jag1 protein.RESULTS AND CONCLUSION:MTT assay showed that carboxymethyl chitosan thermosensitive hydrogel promoted the cell proliferation, and the proliferation rate reached the peak at the concentration of 150 g/L. Western blot assay showed that the cells induced by 150 g/L carboxymethyl chitosan thermosensitive hydrogel extract had significant increases in neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, and β3-tubulin protein expression, and obvious decreases in Notch1 and Jag1 protein expression in comparison with the control group. These results indicate that the carboxymethyl chitosan thermosensitive hydrogel induces rat bone marrow mesenchymal stem cells to differentiate toward neurons, and suppresses the activity of Notch signal pathway in the process of differentiation.

Objective To evaluate the clinical outcomes of periprosthetic femoral fractures (PFF) following hip arthroplasty utilizing locking compression plates (LCP) in regard to tips and tricks on the construction of LCP augmented with locking attachment plate (LAP) and titanium cables (TC).Methods A total of 41 cases of PFF follow hip arthroplasty (THA 3,Hemi-arthroplasty 2) between May 2008 to April 2016 have been retrospectively analyzed.There were 13 males and 28 females with an average age of 70.5±8.6 years,including 11 case of Unified Classification System (UCS) type Ⅳ.3B1.1,21 cases of B2.1 and 9 cases of type C.All were closed fractures caused by simple fall in terms of low-energy injury.Surgical options depended on individual configuration of the fractures with the combination of LCP and LAP or TC.In respect of reduction techniques,minimally invasive plate osteosynthesis (MIPO) was used in 5 cases for type B1.1 and 8 cases for type C,Mini-open in 6 cases for type B1.1 and 1 case for type C.Posterolateral approach with open reduction internal fixation were selected for type B2.1.The patients were followed up periodically.Harris score,Mukundan criteria and complications were recorded.Results Five cases died of the comorbidities (heart failure 3,pulmonary infection 1,multiple organs failure 1) within 1 year postoperatively.The follow-up rate was 78.0％ (32 out of 41 cases) and the average follow-up time was 41 months (ranging 11 to 71 months).No malunion,no reduction lost,no hardware failure,no hip dislocation and revision surgery following PFF care found.All cases showed the signs of fracture healing from 8 to 12 (average 10 weeks) postoperatively except 2 cases of delay union.The postoperative complications shown in 11 cases,including 2 cases of superficial infection of the wound,6 cases of deep vein thrombosis (popliteal vein 2,intramural gastrocnemius vein 4) and 3 cases of the prosthetic loosening.Harris score at the latest follow-up were 91.5±2.1 for group B1.1,77.5±4.2 for group B2.1 and 83.5±3.8 for group C.The LCP lengths were 248.9±24.3 mm,258.6±25.2 mm,280.4±24.0 mm for group B1.1,B2.1 and C respectively.The LCP length of group B1.1 was short than that of group C (P＜0.05).The screw numbers for the proximal fragments were 6.1±1.8,6.5±0.7 and 3.8±0.7 for group B1.1,B2.1 and C respectively.The number of screws used in B1.1 and B2.1 were more than that in C (P＜0.05).The screw numbers for the distal fragments were 3.5±0.5,3.9±0.5 and 5.1±0.8 for group B1.1,B2.1 and C respectively,indicating less screws used in B1.1 and B2.1 than that in C (P＜0.05).The cable numbers were 1.9±1.3,2.5±0.9 and 3.7±0.7 respectively for group B1.1,B2.1 and C (P＜0.05).The LAP used in 2,12 and 6 cases for type B 1.1,B2.1 and C respectively without significant difference statistically (P＞0.05).Conclusion Utilizing LCP for PFF following hip arthroplasty can achieve satisfactory short and mid-term clinical outcomes with the prerequisites of precise and individualized preoperative planning.LCP augmented by LAP and TC is a reliable option with low complication rate.However,type C PFF needs longer plate with more screws at distal fragment and more titanium cables.

Objective:To evaluate the clinical factors affecting the probability of malignant micro-sized (≤10 mm) solitary pulmonary nodules (≤10 mm, micro-sized SPN), and established a clinical prediction model. Methods:Medical records from 102 patients with a pathological diagnosis of micro-sized SPN (Group A), established between June 2012 and March 2014, were reviewed. Clinical data were collected to evaluate the independent predictors of malignant micro-sized SPN using single factor analysis and Logistic regression analysis. A clinical prediction model was subsequently created. Receiver-operating characteristic (ROC) curves were constructed using the prediction model. Between January 2015 and August 2017, data from an additional 10 patients enrolled from January 2015 to August 2017 from Jinhua Guangfu Hospital (Group B) with a pathological y diagnosed micro-sized SPN were used to validate this clinical prediction model. The model was also compared with the Mayo Clinic Model. Results:Median age of 102 patients (Group A) was 55.31±10.77 years old. There were 75.5％malignant nodules and 24.5％benign ones. Logistic regression analysis identified six clinical characteristics (no symptoms, upper lobe, diameter>5 mm, no clear border, not irregular round, no calcification) as independent predictors of malignancy in patients with micro-sized SPN. The area under the ROC curve for our model was 0.922 (95％CI:0.857-0.986). In our model, the diagnosis sensitivity and specificity were 88.3％and 84.0％, respectively. The test power of the model was better compared with the Mayo Clinic Model. Conclusions:In this study, we had found the independent predictors of malignant micro-sized SPN, and developed a prediction model that could accurately identify malignant micro-sized SPN in patients.

Objective To investigate the association between phage-mediated shiga toxin and molecular distribution of CRISPR in Escherichia (E.) coli O26:H11 or NM.Methods A total of 135 E.coli O26:H11 or NM strains were collected from NCBI database.Software CRT and CRISPR Finder were used to extract CRISPR and Excel was used to assign the spacer of unique number and type CRISPR.And the relationship between CRISPR and stx phage was analyzed.Results All the 135 E.coli O26:H11 or NM strains had the CRISPR.For CRISPRI,CRISPR2.1,CRISPR2.2 and CRISPR3-4,19,22,1 and 1 subtypes were found,respectively.According to the four CRISPR sites,the strains could be divided into 40 subtypes.Stx-phage was only observed in the group C of CRISPR.Compared with E.coli of stx-phage negative,E.coli with stx-phage harbored more spacers.Conclusions CRISPR loci was extensively existed in E.coli O26:H11 or NM,and many subtypes were found in these strains.The presence of stx-phage was related to the molecular distribution of CRISPR in E.coli O26:H11 or NM.CRISPR might be a valuable biomarker to identify strains with high virulent potential.

Objective:To investigate the combination of internal fixation for periprosthetic fractures of the proximal femur (PFFF) after hip arthroplasty.Methods:The data of 58 patients with periprosthetic fractures after hip arthroplasty from May 2008 to March 2022 were retrospectively analyzed, including 31 males and 27 females. The average age was 75.5±18.2 years (range, 35-95 years). There were 39 total hip arthroplasty and 19 hemiarthroplasty; 37 biological prosthesis and 21 cemented prosthesis. Intraoperative periprosthetic fractures occurred in 6 cases and 52 cases postoperatively. Unified classification system (UCS): UCS IV.3A1 type 2 cases, 3A2 type 1 case, 3B1.1 type 19 cases, 3B2.1 type 25 cases, 3B3 type 2 cases, 3C type 9 cases. Fracture site: 3 cases in zone A (greater trochanter), 46 cases in zone B (around the femoral stem), and 9 cases in zone C (distal to the tip of the femoral stem. Internal fixation is composed of primary and secondary fixation, the main fixation method was the cerclage of steel wire or titanium cable, locking compression plate, and locking attachment plate fixation. The secondary fixation method was the cerclage of titanium cable, which was required to cover three zones A, B and C to form an overall balanced fixation. The modified Harris hip scores (mHHS), plate length, working length and screw number of different internal fixation combinations were compared.Results:The follow-up time was 54.2±21.6 months (range, 11-86 months). All patients showed signs of fracture healing at 10.2±1.5 weeks (range, 7-13 weeks) after operation, and bony union was observed at 19.6±1.3 weeks (range, 17-22 weeks) after operation. No delayed union or nonunion was observed. After operation, one case had a stress fracture and was revised with double-plate internal fixation; one case had a failed internal fixation and was revised with double-plate internal fixation and a large allograft bone graft. The mHHS score of UCSIV.3B2.1 group (80.3±4.6) was the lowest at 6 months after operation, and the difference between the groups of different types was statistically significant ( F=256.72, P<0.001). The score of simple internal fixation group (91.6±4.2) was higher than that of revision combined with internal fixation group (81.9±4.1), and the difference was statistically significant ( t=8.32, P<0.001). The plate length and working length were 24.9±2.5 cm and 12.6±1.7 cm for UCS IV.3B1.1, 25.4±2.6 cm and 13.6±1.8 cm for 3B2.1 and 28.1±2.5 cm and 4.9±1.9 cm for 3C, respectively ( F=5.33, P=0.005; F=6.78, P<0.001). The number of screws in zone A was significant difference among different UCS types ( F=52.67, P<0.001); UCS IV.3B1.1 (6.5±2.3) and 3B2.1 (6.7±2.2) were more than 3B3 (3.5±1.5) and 3C (3.7±1.6). The number of screws in zone B was significant difference among different UCS types ( F=42.15, P<0.001); The number of UCS IV.3B1.1 (2.3±1.6) and 3B2.1 (2.8±1.9) were significantly more than that of 3B3 (1.0±0.5) and 3C (1.2±0.6). The number of screws in zone C was significant differences among different UCS types ( F=39.62, P<0.001); The number of UCS IV.3B1.1 (3.8±1.9) and 3B2.1 (3.9±1.7) were more than that of 3B3 (2.0±0.5), the difference was statistically significant ( P<0.05). Conclusion:The function of hip after simple internal fixation of proximal femoral periprosthetic fractures was better than that of those who underwent revision at the same time; the number of screws of UCSIV.B1 and B2 is more than that of B3.