Virus hijacking ESCRT system to promote self-replication: a review / 生物工程学报

Endosomal sorting complex required for transport (ESCRT) system drives various cellular processes, including endosome sorting, organelle biogenesis, vesicle transport, maintenance of plasma membrane integrity, membrane fission during cytokinesis, nuclear membrane reformation after mitosis, closure of autophagic vacuoles, and enveloped virus budding. Increasing evidence suggests that the ESCRT system can be hijacked by different family viruses for their proliferation. At different stages of the virus life cycle, viruses can interfere with or exploit ESCRT-mediated physiological processes in various ways to maximize their chance of infecting the host. In addition, many retroviral and RNA viral proteins possess "late domain" motifs, which can recruit host ESCRT subunit proteins to assist in virus endocytosis, transport, replicate, budding and efflux. Therefore, the "late domain" motifs of viruses and ESCRT subunit proteins could serve as promising drug targets in antiviral therapy. This review focuses on the composition and functions of the ESCRT system, the effects of ESCRT subunits and virus "late domain" motifs on viral replication, and the antiviral effects mediated by the ESCRT system, aiming to provide a reference for the development and utilization of antiviral drugs.

Risk factors for calcaneal fracture combined with vertebral fracture / 中华创伤骨科杂志

Objective:To analysis the risk factors for calcaneal fracture combined with vertebral fracture.Methods:A retrospective study was performed of the 745 calcaneal fractures which had been surgically treated from May, 2005 to September, 2020 in Nanjing Drum Tower Hospital Affiliated to Medical School, Nanjing University. There were 651 males and 94 females, aged from 11 to 89 years (mean, 43.8 years). The incidence of calcaneal fracture combined with vertebral fracture was recorded. The risk factors were screened out by univariate analysis from gender, age, body mass index, unilateral or bilateral calcaneal fractures, injury severity score (ISS), cause of injury, fall height, classifications of calcaneal and number of vertebral fracture; binary logistic regression analysis was used to determine independent risk factors from the rtsk factors with P<0.05. Results:Vertebral fracture occurred in 70 of the 745 patients with calcaneal fracture (9.40%). Univariate analysis showed significant differences in gender, body mass index, unilateral or bilateral calcaneal fractures, ISS and fall height between patients with simple calcaneal fracture and patients with calcaneal fracture combined with vertebral fracture ( P<0.05); Binary logistic regression analysis showed that gender ( OR=0.225, 95% CI:0.095~0.532, P=0.001), unilateral or bilateral calcaneal fractures ( OR=3.582, 95% CI:1.705~7.526, P=0.001), ISS ( OR=5.229, 95% CI:1.605~17.035, P=0.006), and fall height ( OR=49.820, 95% CI:23.068~107.597, P<0.001) were the independent risk factors for calcaneal fracture combined with vertebral fracture. Conclusion:A more likely combined vertebral fracture should be taken into consideration in male patient with bilateral calcaneal fractures, a falling height > 3 m, or a high ISS.

Construction and identification of an apoptosis detection system based on firefly luciferase reporter gene / 生物工程学报

To construct a eukaryotic expression plasmid containing the luciferase reporter gene (Fluc) to quickly detect apoptosis. Four amino acids, Asp-Glu-Val-Asp (DEVD), the recognize motif of Caspase-3, were introduced into the middle of the Fluc-C and N fragment. Meanwhile, four amino acids, Asp-Glu-Val-Gly (DEVG), were selected as a negative control. Subsequently, the recombinant gene was cloned into the N and C terminal end of the split intein, and named as pFluc-DEVD and pFluc-DEVG. Then the plasmids were transfected into cells and renilla luciferase was co-transfected in each sample as an internal control for transfection efficiency. Then the apoptosis level was detected by the double luciferase reporter gene and the Western blotting analysis. The results showed that when apoptosis occurred, the content of firefly luciferase expressed in the pFluc-DEVD plasmid transfected group was about 3 times higher than pFluc-DEVG plasmid transfected group. Furthermore, Western blotting detection indicated that the Fluc level was significantly increased in pFluc-DEVD transfected group when pre-treated by apoptosis stimulants. The activation degree of Caspase-3 was closely related to the expression of Fluc, and had a significant statistical difference. These results confirmed that firefly luciferase protein expressed by pFluc-DEVD plasmid can be cleaved by the intracellular Caspase-3 enzyme, and this plasmid can accurately reflect the cell apoptosis level, which provides a useful method for quantitative detection of apoptosis.

Chicken RNA-binding protein T-cell internal antigen-1 contributes to stress granule formation in chicken cells and tissues

T-cell internal antigen-1 (TIA-1) has roles in regulating alternative pre-mRNA splicing, mRNA translation, and stress granule (SG) formation in human cells. As an evolutionarily conserved response to environmental stress, SGs have been reported in various species. However, SG formation in chicken cells and the role of chicken TIA-1 (cTIA-1) in SG assembly has not been elucidated. In the present study, we cloned cTIA-1 and showed that it facilitates the assembly of canonical SGs in both human and chicken cells. Overexpression of the chicken prion-related domain (cPRD) of cTIA-1 that bore an N-terminal green fluorescent protein (GFP) tag (pntGFP-cPRD) or Flag tag (pFlag-cPRD) induced the production of typical SGs. However, C-terminal GFP-tagged cPRD induced notably large cytoplasmic granules that were devoid of endogenous G3BP1 and remained stable when exposed to cycloheximide, indicating that these were not typical SGs, and that the pntGFP tag influences cPRD localization. Finally, endogenous cTIA-1 was recruited to SGs in chicken cells and tissues under environmental stress. Taken together, our study provide evidence that cTIA-1 has a role in canonical SG formation in chicken cells and tissues. Our results also indicate that cPRD is necessary for SG aggregation.

Research concerning the effect of analgesics on fracture healing / 中华创伤骨科杂志

Analgesics are widely used in fracture patients before and after operation.The analgesics frequently used include non-steroidal anti-inflammatory drugs,as well as central nerve and local medications.Recently,researches report that some analgesics may inhibit fracture healing,which has attracted much attention from orthopedic surgeons.However,there are researchers who hold opposite opinions.Accordingly,this paper reviews the progress in research concerning the effect of analgesics on fracture healing.

Clinical outcomes of induced membrane technique in treatment of traumatic segmental bone defects / 中华创伤骨科杂志

Objective To evaluate the clinical outcomes of induced membrane technique in the treatment of traumatic segmental bone defects.Methods From May 2011 to January 2016,we treated 10 patients with traumatic segmental bone defect of the lower limb.They were 7 men and 3 women,with an average age of 41.6 years (from 18 to 61 years.The bone defects involved 8 tibias and 2 femurs;the mean length of the bone defects was 5.1 cm (from 2 to 15 cm).All the segmental bone defects were teated by induced membrane technique.At the first stage,the bone defects were filled with antibiotic-impregnated cement spacer after thorough debridement,the limb was fixated with external fixtor,and soft tissue repair was performed in 5 patients.On average all the patients received emergency treatment at the first stage 8.1 hours (from 4 to 13 hours) after trauma.At the second stage,after the cement was removed,the bone defects were filled with cancellous autografts.An allograft was used when the autograft was not adequate enough.The external fixtor was exchanged by internal fixation in one patient according to his soft tissue condition and will;the exteranl fixation was retained in the other 9 patients.Results The average follow-up was 2.8 years (from 1.0 to 5.5 years).Bone healing was achieved in 9 patients after an average of 7.1 months (from 5 to 9 months),and nonunion happened in one patient whose bone graft had been not sufficient enough.Stress fracture occurred in one patient 7 months after bone healing,but it responded to conservative management.One patient reported numbness on the anterolateral thigh of the donor site.Pin tract infection occurred in 3 patients.Follow-ups revealed no limb length discrepancy or deep infection.Conclusion Induced membrane technique is a simple and reliable technique for the treatment of traumatic segmental bone defects.

Factors influencing articular function after surgery for ankle fractures / 中华创伤骨科杂志

Objective To analyze the factors that influence the articular function after open reduction and internal fixation for ankle fractures.Methods From July 2014 to January 2016,111 ankle fractures received surgery in our hospital.There were 54 males and 57 fenales,with a mean age of 43.5 years (frown 18 to 75 years).By the Broos & Bisschop classification,there were 43 unimalleolar,38 bimalleolar and 30 trimalleolar fractures.The postoperative articular function was evaluated according to the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scoring at the final follow-up.Comparisons were made between the patients with excellent functional scores and those with lower than excellent functional scores.The potential influencing factors were analyzed,including age,gender,body mass index,smoking history,primary hypertension history,diabetes history,injured side,fracture cause,Broos & Bisschop classification,combined presence of obvious inferior tibiofibular separation,combined presence of ankle dislocation,combined presence of other injury,time from injury to surgery,physical status classification by the American Society of Anesthesiologists system,operation time,early functional exercise,removal of internal fixation and postoperative complications.The influencing factors were identified using univariate analysis and logistic regression analysis.Results The average follow-up period was 15.5 months (from 8 to 25 months).The clinical union time of the fractures averaged 3.2 months (from 3 to 5 months).The ankle function at the final follow-up was excellent in 58 cases,good in 48,fair in 5 and poor in 0,with an excellent and good rate of 95.5％.Removal of internal fixation (P =0.001),early functional exercise (P =0.002),and postoperative complications (P =0.049) were identified as the independent risk factors influencing the articular function after surgery for ankle fractures.Conclusion For patients with ankle fracture,enhancing intraoperative procedures,reducing postoperative complications,encouraging the patients to do early functional exercise,and removing internal fixation after firacture union can effectively improve their ankle function.

Factors influencing articular function after surgery for ankle fractures / 中华创伤骨科杂志

Objective To analyze the factors that influence the articular function after open reduction and internal fixation for ankle fractures.Methods From July 2014 to January 2016,111 ankle fractures received surgery in our hospital.There were 54 males and 57 fenales,with a mean age of 43.5 years (frown 18 to 75 years).By the Broos & Bisschop classification,there were 43 unimalleolar,38 bimalleolar and 30 trimalleolar fractures.The postoperative articular function was evaluated according to the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scoring at the final follow-up.Comparisons were made between the patients with excellent functional scores and those with lower than excellent functional scores.The potential influencing factors were analyzed,including age,gender,body mass index,smoking history,primary hypertension history,diabetes history,injured side,fracture cause,Broos & Bisschop classification,combined presence of obvious inferior tibiofibular separation,combined presence of ankle dislocation,combined presence of other injury,time from injury to surgery,physical status classification by the American Society of Anesthesiologists system,operation time,early functional exercise,removal of internal fixation and postoperative complications.The influencing factors were identified using univariate analysis and logistic regression analysis.Results The average follow-up period was 15.5 months (from 8 to 25 months).The clinical union time of the fractures averaged 3.2 months (from 3 to 5 months).The ankle function at the final follow-up was excellent in 58 cases,good in 48,fair in 5 and poor in 0,with an excellent and good rate of 95.5％.Removal of internal fixation (P =0.001),early functional exercise (P =0.002),and postoperative complications (P =0.049) were identified as the independent risk factors influencing the articular function after surgery for ankle fractures.Conclusion For patients with ankle fracture,enhancing intraoperative procedures,reducing postoperative complications,encouraging the patients to do early functional exercise,and removing internal fixation after firacture union can effectively improve their ankle function.

New studies on adjunctive therapies for osteomyelitis / 中华创伤骨科杂志

Osteomyelitis,particularly chronic one,is still a huge challenge to orthopedic surgeons.The current treatment for osteomyelitis centers on sensitive antibiotic coverage and surgical debridement of nonviable tissue.However,treatment failure and recurrence are common.Recently,adjunctive therapies such as hyperbaric oxygenation have been widely applied in treatment of osteomyelitis to promote sanative effect on osteomyelitis.In this review,we will outline the rationales and current status of potential adjunctive therapies in osteomyelitis management.

Progress in imaging research on the diagnosis of chronic osteomyelitis / 中华创伤骨科杂志

The imaging techniques have been widely used in the diagnosis of chronic osteomyelitis,including plain radiography,magnetic resonance imaging,computed tomography and radionuclide imaging.Plain radiography is useful in the early detection of suspected osteomyelitis,but its sensitivity is low.Due to its high resolution and sensitivity,MRI has been the most widely used but its specificity is relatively poor.CT is mainly recommended for diagnosis of chronic osteomyelitis in complicated anatomic regions.Radionuclide imaging will have prospects of broad application due to its diverse radiotracers and high sensitivity.This paper reviewed the research of imaging modalities in diagnosis of chronic osteomyelitis.

Risk evaluation on aorta injury caused by misplacement of thoracic pedicle screws in the treatment of adolescent idiopathic scoliosis / 中华骨科杂志

Objective To evaluate the potential risk of aorta injury by simulating different lateral misplacement patterns of thoracic pedicle screws (TPS) in the treatment of adolescent idiopathic scoliosis (AIS).Methods From December 2010 to August 2011,50 AIS patients were admitted to our hospital,including 7 males and 43 females,aged from 13 to 18 years (average,15.3±2.6 years).All patients underwent axial magnetic resonance imaging (MRI) scans from T5 to T12.The left pedicle-aorta (LtP-Ao) angle and distance were measured on the axial MR images by the software of PACS Client.The lateral misplacement of pedicle screw was simulated with variable direction errors (10°,20°,30°) and different lengths of pedicle screw (30 mm,35 mm,40 mm).A total of nine patterns of lateral pedicle screw misplacement were set up,and a warning misplacement was defined as the mimic pedicle screw crossed the aorta.The percentages of warning misplacement were compared in each pattern of lateral pedicle screw misplacement and each level from T5 to T12.Correlation analysis was made between the percentages of warning misplacement and the direction errors as well as length of pedicle screw.Results The mean LtP-Ao angle increased from 34.3°±8.5° at T5 level to 45.7°±4.1° at T7 level,and then gradually decreased to 9.2°±5.6° at T12 level.The mean LtP-Ao distance increased from 28.2±7.3 mm at T5 level to 37.7±6.5 mm at T12 level.The percentages of warning misplacement were positive correlation with the direction errors and length of pedicle screw.The percentage of warning misplacement was higher at the T11 level.Conclusion The potential risk of aorta injury increases with enlarging of direction error and lengthening of thoracic pedicle screw,particularly at the T11 level.

The measurement of femoral head-neck ratio and its clinical significance in Chinese / 中华骨科杂志

Objective To measure the femoral head-neck ratio among Chinese adults in Nanjing to explore its clinical significance. Methods 468 Chinese without hip symptoms were chosen randomly. There were 313 males and 155 females. 13 cases were less than 20 years old, 88 cases were from 21 to 30 years old, 123 cases were from 31 to 40 years old, 104 cases were from 41 to 50 years old, 102 cases were from 51 to 60 years old, 24 cases were from 61 to 70 years old, 14 cases were more than 71 years old. The mean age was 42.4 years old (ranged from 17 to 82 years old). The maximum diameter of the femoral head and the minimum vertical diameter of femoral neck length on both sides were measured by Digimizer software in the standard anteroposterior pelvis film. The femoral head-neck ratio (FHNR) was calculated and compared with that of the western. Results The normal FHNR of Chinese in Nanjing was 1.48 ± 0.09 (1.33-1.69). FHNR was 1.46±0.09 in Chinese aged less than 20 years old. It was 1.48±0.09 in Chinese aged from 21 to 30 years, and 1.47±0.10 in those aged 31-40 years, 1.46±0.09 in 41-50 years, 1.49±0.10 in 51-60 years,1.48±0.08 in 61-70 years, 1.49±0.10 in those more than 71 years. There was no difference between male and female, the left and right side or the different age groups. There was no difference between the western and Chinese in Nanjing. Conclusion FHNR measurement has not variation with regard to sex, age and side. It may be useful to understand some kind of the hip diseases.

Articulating spacer in the two-stage revision for severe infected knee arthroplasty / 中华骨科杂志

Objective To investigate the efficiency and safety of articulating spacer for severe infected knee arthroplasty in patients with medical comorbidities and local sinus tracts. Methods Ten consecutive patients with medical comorbidities (rheumatoid arthritis, diabetes mellitus, etc) or local sinus tracts,who were complicated with late infected TKA, were included in the study. All the patients underwent twostage revision using articulating spacers. All of the patients were debridement thoroughly and followed by implantation of an antibiotic-loaded cement articulated spacer. Two-stage revisions were not followed untill the infection were controlled. The hospital for special surgery (HSS) knee scoring system and range of motion were used to evaluate the outcomes. Results One patient underwent knee fusion because the infection was not controlled after first-stage surgery. The other 9 patients had no evidence of infection. The mean follow-up was 50 months (range, 24-90 months), no recurrent infection developed for these 9 patients. The mean modified HSS score had improved from 48 points (range, 32-63) before the resection surgery to 79 points (range,62-91) at the end of the spacer period. At the latest follow-up, the modified HSS score averaged 89 points (range, 74-95). The good and excellent rate was 0, 80% and 100%, respectively. The average range of motion had increased from 13°-70° preoperatively to 8°-93° prior to the revision. And at the latest follow-up, the range of motion averaged 3° to 110°. Conclusion The delayed two-stage revision using an articulating spacer is effective in the treatment of chronically infected TKA characterized by simple, good reproducible, high rate of infection control, better joint function after surgeries