Osteonecrosis of the femoral head (ONFH) is one of the common and difficult-to-treat orthopedic diseases caused by a variety of factors that lead to abnormal blood flow to the femoral head, which in turn leads to deformation and collapse of the femoral head and eventually results in severe hip joint dysfunction. The key to the treatment is early diagnosis and correct treatment according to the stage classification and active prevention of further aggravation of ONFH aiming to delay or avoid hip replacement surgery in young and middle-aged patients. At present, there are various non-surgical and surgical hip-preserving modalities for early ONFH, designed to slow down the progression of the disease, prevent the femoral head from collapsing and stop the mild collapse. In recent years, with the emergence and development of bone reconstruction biomaterials, artificial bone reconstruction after scraping of ONFH lesions has shown great potential in the treatment of early ONFH. The authors review the research progress in hip-preserving modalities for early ONFH in young and middle-aged patients from non-surgical and surgical perspectives, hoping to provide a reference for clinical treatment of early ONFH.

Femoral neck fracture (FNF) in the elderly patients is currently a major health challenge worldwide, with excessive consumption of medical resources, high incidence of complications as well as suboptimal outcome and prognosis. Hip joint arthroplasty (HJA) has been the mainstream treatment for FNF in the elderly, but the conventional surgical approaches and techniques are still confronted with a series of bottlenecks such as dislocation, limp and limb length discrepancy. In recent years, direct anterior approach (DAA) for HJA (DAA-HJA) has been a major new choice in the field of joint replacement, which achieves improved clinical effectiveness of HJA in the treatment of elderly FNF, due to the fact that DAA approach involves the neuromuscular interface and accords with the idea of soft tissue retention and enhanced recovery after surgery. However, there is still a lack of unified understanding of standard technique and procedure of DAA-HJA in the treatment of elderly FNF. Therefore, relevant experts from the Hip Joint Group of Chinese Orthopedics Association of Chinese Medical Association, Youth Arthrology Group of Orthopedic Committee of PLA, Orthopedic Committee of Chongqing Medical Association, Branch of Orthopedic Surgeons of Chongqing Medical Doctor Association and Sport Medicine Committee of Chongqing Medical Association were organized to formulate the " Chinese expert consensus on the technical standard of direct anterior hip arthroplasty for elderly femoral neck fracture ( version 2023)" based on evidence-based medicine. This consensus mainly proposed 13 recommendations covering indications, surgical plans, prosthesis selections, surgical techniques and processes, and postoperative management of DAA-HJA in elderly patients with FNF, aiming to promote standardized, systematic and patient-specific diagnosis and treatment to improve the functional prognosis of the patients.

Objective:To investigate the efficacy of single locked-plate internal fixation combined with autologous iliac bone graft in the treatment of Rorabeck type II periprosthetic distal femural fracture (PDFF) after total knee arthroplasty (TKA).Methods:A retrospective case series study was made on 13 patients suffering from Rorabeck type II PDFF after primary TKA together with severe osteoporosis (T value≤ -2.5 SD) admitted to 940th Hospital of Joint Logistics Support Force of PLA from January 2016 to December 2020, including 4 males and 9 females, aged 65-85 years [(75.2±6.5)years]. All patients were treated with single locked-plate internal fixation combined with autologous iliac bone graft. Anti-osteoporosis and early standardized joint function rehabilitation were undertaken postoperatively. The operation time and intraoperative blood loss were recorded. The range of motion of knee joint was compared before operation, at postoperative 3, 6 and 12 months and at the last follow-up. The Hospital for Special Surgery (HSS) knee score was assessed at postoperative 3, 6 and 12 months and at the last follow-up to evaluate the recovery of knee joint function. The bone mineral density was reexamined at postoperative 6 months and 12 months to evaluate the therapeutic effect of anti-osteoporosis. Complications were detected as well.Results:All patients were followed up for 12-72 months [(43.2±19.9)months]. The operation time was 90-135 minutes [(103.8±12.6)minutes], with the intraoperative blood loss of 100-250 ml [(150.0±45.6)ml]. The range of motion of knee joint was (114.6±7.8)°, (90.4±8.0)°, (97.3±4.8)° and (98.1±6.3)° before operation and at postoperative 3, 6 and 12 months (all P<0.05). The HSS knee score was (80.2±2.2)points, (84.6±2.9)points and (87.3±3.3)points at postoperative 3, 6 and 12 months (all P<0.05). The knee joint function was excellent in 10 patients and good in 3 at postoperative12 months, and the excellent and good rate was 100%. The T value of bone mineral density was (-3.8±0.6)SD, (-3.4±0.6)SD and (-2.9±0.6)SD preoperatively and at postoperative 6 months and 12 months (all P<0.05). One patient experienced nonunion and was cured after secondary autologous iliac bone grafting combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) bone grafting. Three patients developed venous thrombosis of lower limbs and were cured with oral administration of rivaroxaban. One patient had mild knee flexion and extension limitation and was improved after manual release under femoral nerve block anesthesia and subsequent functional rehabilitation. Conclusion:For patients with Rorabeck type II PDFF after TKA, single locked-plate internal fixation combined with autologous iliac bone graft has advantages of short operation time, few intraoperative bleeding, satisfactory knee range of motion and functional recovery as well as significant improvement of bone mineral density.

Transcription factor-based biosensors (TFBs) play an essential role in metabolic engineering and synthetic biology. TFBs sense the metabolite concentration signals and convert them into specific signal output. They hold high sensitivity, strong specificity, brief analysis speed, and are widely used in response to target metabolites. Here we reviewe the principles of TFBs, the application examples, and challenges faced in recent years in microbial cells, including detecting target metabolite concentrations, high-throughput screening, adaptive laboratory evolutionary selection, and dynamic control. Simultaneously, to overcome the challenges in the application, we also focus on reviewing the performance tuning strategies of TFBs, mainly including traditional and computer-aided tuning strategies. We also discuss the opportunities and challenges that TFBs may face in practical applications, and propose the future research trend.
Biosensing Techniques ; Gene Expression Regulation ; Metabolic Engineering ; Synthetic Biology ; Transcription Factors/metabolism*

Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.
Aerobiosis ; Denitrification ; Nitrification ; Nitrogen ; Waste Water

Acute ST segment elevation myocardial infarction(STEMI) is caused by plaque rupture, followed by thrombosis and acute occlusion of blood vessels.In some patients with acute myocardial infarction(AMI), although infarction-related coronary arteries are opened by revascularization, there is no reflow due to the associated coronary microcirculation.Increase the incidence and mortality of short-term and long-term cardiovascular events.On the contrary, although the associated coronary artery is still occluded in some AMI patients, the myocardial microcirculation in the perfusion area can be perfused by collateral circulation, resulting in the decrease of the elevated ST segment.Therefore, in the process of diagnosis and treatment of AMI, paying attention to the structural and functional changes of coronary artery microcirculation should be an important research field.More and more evidence shows that coronary artery microcirculation plays an important role in myocardial blood supply.Through the use of thermal dilution pressure catheter, microcirculation resistance index (IMR) can measure the function of microcirculation.IMR is a specific index to reflect microcirculation, which is different from the traditional evaluation method, and has multiple advantages, such as simple operation, strong repeatability, high specificity and so on.In recent years, the research on the correlation of IMR is advancing by leaps and bounds.This paper reviews the current research progress on the correlation of IMR in STEMI.

Objective To explore the feasibility and therapeutic effects of total hip replacement (THR) for intertrochanteric fractures combined with late necrosis of the femoral head.Methods From June 2010 to October 2015,8 patients underwent THR for intertrochanteric fractures combined with necrosis of the femoral head.They were 6 males and 2 females,with an average age of 53.5 years(from 45 to 67 years).According to the Evans-Jensen classification,2 fractures were type ⅠB,5 type ⅡA and one type ⅡB.All the 8 fractures were complicated with late femoral head necrosis,5 cases of which were ischemic.According to the Ficat classification,the ischemic necrosis was type Ⅲ in one and type Ⅳ in 5 cases.In the other 3 cases,the necrosis secondary to the hip osteoarthrosis was type Ⅲ according to the Tonnis classification.The necrotic femoral head was removed after osteotomy of the femoral neck via the posterolateral approach;after reduction of the femoral calcar,the intertrochanteric fracture was reduced and fixated in a press-fit manner through antegrade implantation of a biological stem prosthesis.Functional assessment of the affected hip was carried out at the final follow-up using Harris scoring.Results The 8 patients were followed up for an average of 25.5 months (from 12 to 45 months).After operation,biological press-fit and initial stability of the femoral stem were achieved in all the patients.The X-ray films showed bone ingrowth fixation in all the 8 hips at 3 months postoperatively.The Harris hip scores at the final follow-up averaged 92.3(from 89 to 98).The patients showed fine subjective satisfaction.Follow-ups revealed no infection,prosthetic failure,osteolysis,dislocation or articular instability.Conclusion In treatment of intertrochanteric fractures combined with necrosis of the femoral head,THR can lead to fixation and reduction of the intertrochanteric fracture and replacement of the necrotic femoral head at one stage,promoting functional recovery of the affected hip.

Objective To investigate the clinical outcomes of total hip arthroplasty in treatment of severe acetabular protrusion secondary to rheumatoid arthritis.Methods From January 2011 to November 2014,eighteen patients (20 hips) with severe acetabular protrusion secondary to rheumatoid arthritis were treated with total hip arthroplasty (THA),including 6 males (6 hips) and 12 females (14 hips).The age ranged from 37 to 68 years (average,45.8±8.3 year).According to the classification of Sotelo-Garza and Charnley,there were 15 cases (17 hips) of type Ⅱ (acetabular protrusion 6-15 mm) and 3 cases (3 hips) of type Ⅲ (acetabular protrusion ＞ 15 mm).During the surgery,the femoral heads were moved out through retrograde method after the osteotomy of femoral neck by posterolateral approach.All patients underwent THA with autogenous bone graft by impacting technique for reconstruction of acetabula,and the cementless cups were planted with press-fit skills (Tantalum trabecular metal cup in 16 cases and Titanium porous coating cup in 4 cases).The hip function was evaluated by using Harris hip score.Radiographic measurement was performed with X-ray films to assess the restoration of the hip rotation center,graft incorporation and sign of prostheses loosening in follow-up duration.Results The mean operation duration and intraoperative blood loss were 89.5±8.1 min (range 55-131 min) and 295±10.9 ml (range 165-480 ml) respectively.The average amount of bone graft was 33.7±6.8 cm3 (range 32.5-61.2 cm3) in reconstruction of protrusion acetabulum.The mean follow up duration was 4.5± 1.7 years (range 2.5-6.0 years).The horizontal distance between the center of femoral head and the Kohler's line was increased from preoperative 8.87±3.9 mm (range-11.11-12.78 mm) to 23.55 ± 2.5 mm (range 21.23-25.57 mm) postoperatively,and the vertical distance between the center of femoral head and the line joining the bilateral ischial tuberosities was decreased from preoperative 87.45 ± 3.5 mm (range 74.75-96.97 mm) to postoperative 77.83±4.1 mm (range 68.22-90.40 mm) with statistically significant difference.The bone incorporation was achieved at 6 months postoperatively in radiological film.No loosening of acetabular components was found in final fellow-up.At last follow-up,Harris hip score was significantly improved from 55.3±9.5 points preoperatively to 92.2±12.7 postoperatively (t=51.569,P=0.000).The range of flexion of the hip significantly improved from 41.5°±6.7° preoperatively to 102.3°±14.5° at finial follow-up (t=64.865,P=0.000),and the range of extension of the hip improved from 8.2°±3.5° preoperatively to 29.8°±6.6° at finial follow-up (t=51.161,P=0.000).The discrepancy was significantly decreased from 23.7±0.82 mm preoperatively to 4.7±0.39 mm postoperatively (t=19.761,P=0.000).Mild thigh pain was reported in two hips,which typically occurred only with prolonged activity without disabling and not requiring medication.Conclusion Total hip arthroplasty with impaction bone grafting and cementless modular cup can recover the acetabular center of rotation and achieve satisfactory short-term outcomes in treating patients severe protrusion acetabula secondary to rheumatoid arthritis.

To observe the influence of matrix metalloproteinases-2 (MMP-2), monocyte chemoattractant protein-1 (MCP-1), CD47, L-selectin and advanced oxidation proteinproducts (AOPP) in osteoarthritis and the intervention of curcumin.A total of 20 male C57BL/6 mice (10.05-15.00 g) were randomly divided into control group, OA group, Cur25 group and Cur50 group (intraperitoneal injected 25 μmol/L or 50 μmol/L of curcumin everyday after modeling). After 4 weeks treatment, we observed the morphological changes of the gross specimen by immunohistochemical method, and observed the ultrastructure of cartilage tissue under electron microscope. The expression of MMP-2, MCP-1 and CD47 were detected by western blotting, and L-selectin and AOPP were detected by ELISA and spectrophotometer, respectively.In the cartilage tissue morphology, the chondrocytes of OA group showed obvious change, while Cur25 and Cur50 groups maintained the good cartilage cell membrane intact. Compared with control group, the expressions of MMP-2, MCP-1, L-selectin and AOPP in OA group, Cur25 group and Cur50 group were increased (all<0.05), while CD47 levels were decreased (all<0.05). Compared with OA group, the expressions of MMP-2, MCP-1, L-selectin and AOPP in Cur25 group and Cur50 group were decreased (all<0.05), while CD47 levels were increased (all<0.05), and such changes were more significant in Cur50 group (all<0.05).The MMP-2, MCP-1, CD47, L-selectin and AOPP are closely associated with the pathology course of OA. Curcumin has protection effect on cartilage, which can relieve joint cartilage degeneration, reduce cartilage inflammation and increase the metabolic activity of chondrocytes.
Advanced Oxidation Protein Products ; metabolism ; Animals ; Biomarkers ; CD47 Antigen ; metabolism ; Cartilage ; chemistry ; drug effects ; pathology ; Chemokine CCL2 ; metabolism ; Chondrocytes ; drug effects ; pathology ; Curcumin ; administration & dosage ; pharmacology ; Cytokines ; L-Selectin ; metabolism ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Mice, Inbred C57BL ; Osteoarthritis ; genetics ; pathology ; physiopathology ; Oxidative Stress

To investigate the effect of diosgenin (Dgn) on chondrocytes and its relation to JAK2/STAT3 signaling pathway in mice with osteoarthritis (OA).Fifteen male C57BL/6 mice were randomly divided into three groups:control group, OA group and OA+Dgn group. After 4 weeks of treatment, the histopathological changes of cartilage tissue were observed by toluidine blue staining under light microscopy and the ultrastructure of chondrocytes was observed under electron microscopy. The primarily cultured chondrocytes of OA mice were randomly divided into 4 groups:(1) OA group, (2) Dgn group, (3) Dgn+AG490 group, (4) AG490 group. The expression of p-JAK2, p-STAT3, Bax, succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) were detected by Western blotting, and superoxide dismutase (SOD) was detected using colorimetric method.The morphological observation showed that the chondrocytes of OA group presented considerable pathological changes, while the chondrocytes in OA+Dgn group maintained intact membrane. Electron microscopy observation found obvious injury in cartilage tissues of OA group, while that in OA+Dgn group remained smooth. Compared with OA group, the expressions of p-JAK2 and p-STAT3 in chondrocytes of Dgn group were increased (all<0.05), and the expressions of Bax protein, SDH, COX and SOD were decreased (all<0.05). While compared with Dgn group, the expressions of p-JAK2, p-STAT3, SDH, COX and SOD in chondrocytes of Dgn+AG490 group were decreased (all<0.05), and the expression of Bax protein was increased (<0.05).Diosgenin can inhibit apoptosis and increase mitochondrial oxidative stress capacity of chondrocytes in mice with osteoarthritis, which is closely related to the activation of JAK2/STAT3 signaling pathway.
Animals ; Apoptosis ; drug effects ; Cartilage ; drug effects ; pathology ; Chondrocytes ; chemistry ; drug effects ; pathology ; Diosgenin ; pharmacology ; Electron Transport Complex IV ; metabolism ; Janus Kinase 2 ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Mitochondria ; drug effects ; genetics ; Osteoarthritis ; genetics ; physiopathology ; Oxidative Stress ; drug effects ; STAT3 Transcription Factor ; drug effects ; Signal Transduction ; Succinate Dehydrogenase ; metabolism ; Superoxide Dismutase ; metabolism ; Tyrphostins ; pharmacology ; bcl-2-Associated X Protein ; metabolism