Research progress in mechanism of action and application of mesenchymal stem cell-derived exosomes in repair of bone defects / 中华创伤杂志

Bone defects are bone loss caused by factors such as severe trauma, infection, tumor resection and congenital malformations. Bone transplantation, induced membrane technique or stem cell bone tissue engineering is needed for the defects that are difficult to heal naturally. However, the techniques related to bone transplantation are complex and have limited application scope; the induced membrane technique shows uncontrollable cement degradation rate and requires a second surgery; the stem cell bone tissue engineering still has some unstable factors such as undirected differentiation of stem cells. Exosomes are the key liposomes in the communication between cells. Compared with natural stem cell-derived exosomes, engineered exosomes with the advantages of high production and low immunogenicity are expected to replace stem cells in clinical applications. The authors review the mechanism of action of mesenchymal stem cell (MSC)-derived exosomes in repairing bone defects and application of engineered exosomes based on MSC in bone regeneration, so as to provide new ideas for the basic research and clinical treatment of bone defects.

Construction of an online nomogram of risk factors for postoperative delirium in elderly patients with hip fracture / 中华创伤骨科杂志

Objective:To investigate the risk factors for postoperative delirium in the elderly patients with hip fracture and to construct an online nomogram of the risk factors.Methods:Retrospectively analyzed were the data of 483 elderly patients with hip fracture who had been treated with artificial joint replacement from May 2020 to August 2021 at Department of Orthopaedics (Department of Joint Surgery), Jinling Hospital Affiliated to Medical College of Nanjing University. There were 166 males and 317 females, aged from 61 to 99 years (average, 82.1 years). Fracture types: 333 femoral neck fractures and 150 intertrochanteric fractures. The patients were divided into a delirium group ( n=149) and a delirium-free group ( n=334) according to whether postoperative delirium occurred after surgery. The 2 groups were compared in terms of general data like age, gender, body mass index, and concomitant diseases, as well as in terms of indexes like pre-operative albumin, preoperative hemoglobin, and postoperative C-reactive protein (CRP). Factors with P < 0.05 were included in the multi-factor logistic regression analysis to screen out the risk factors for postoperative delirium. The "rms" package of R software was used to draw the nomogram; the Bootstrap method was used to repeat the sampling 1,000 times for evaluation, calculation of the consistency index ( CI), and drawing of the ROC curve and correction curve; the decision curve was plotted using the "rmda" package. Results:There were significant differences between the delirium group and the delirium-free group in age, preoperative anxiety, Alzheimer＇s disease, history of cerebrovascular disease, preoperative albumin, intraoperative hypotension and postoperative CRP ( P < 0.05). The multifactorial logistic regression analysis showed that high age, preoperative anxiety, Alzheimer＇s disease, preoperative albumin < 35 g/L, and postoperative CRP ≥90 mg/L were the risk factors for postoperative delirium in the elderly patients with hip fracture after artificial joint replacement ( P < 0.05). The area under the ROC curve of the nomogram constructed by incorporating the risk factors for postoperative delirium was 0.894 (95% CI: 0.865 to 0.923) with a CI of 0.889; the calibration curve showed that the calibration curve of this nomogram model tended to be close to the ideal curve. The decision curve analysis showed that the threshold value was 0.01 to 1.00, showing the net benefit rate of this nomogram model > 0 when used to predict the postoperative delirium in the elderly patients with hip fracture. Conclusions:High age, preoperative anxiety, Alzheimer's disease, preoperative albumin < 35 g/L, and postoperative CRP ≥90 mg/L may be the risk factors for postoperative delirium in the elderly patients with hip fracture after artificial joint replacement. The online nomogram based on these factors demonstrates a good value in prediction of postoperative delirium.

Debridement, antibiotics irrigation and implant retention for acute periprosthetic joint infection after primary total joint arthroplasty / 中华创伤骨科杂志

Objective:To analyze the clinical efficacy of debridement, antibiotics irrigation and implant retention (DAIR) in the treatment of acute periprosthetic infection (PJI) and to explore the risk factors leading to the failure of DAIR.Methods:From January 2010 to January 2021, 122 patients underwent DAIR for acute PJI at Department of Orthopedics, General Hospital of Eastern Theater of PLA. They were 55 males and 67 females, aged from 50 to 86 years (mean, 68.0 years). Their C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), body temperature, white blood cell count and visual analogue scale (VAS) were compared at admission and discharge to analyze the clinical efficacy of DAIR. The 122 patients were assigned into a cured group (81 cases) and an uncured group (41 cases). Risk factors were screened by univariate analysis out of their gender, age, body mass index, site of infection, type of infection (early postoperative infection or acute hematogenous infection), type of surgery (primary or revision), comorbidities, CRP, ESR, albumin and hemoglobin at admission, duration of symptoms, Staphylococcus aureus infection, multiple bacterial mixed infection, and preoperative sinus tract. For the factors of P<0.05, multivariate binary logistic regression analysis was used to determine the risk factors for failure of DAIR. Survival curves were plotted for the patients using DAIR failure as the endpoint event. Results:The CRP, ESR, VAS score, body temperature and white blood cell count at discharge in the 122 patients were significantly lower than the corresponding values at admission ( P<0.05). The success rate of DAIR was 66.39%(81/122). The multivariate binary logistic regression analysis suggested that duration of symptoms over 3 weeks( OR=1.230, 95% CI: 1.092~1.576, P=0.020), Staphylococcus aureus infection( OR=4.607, 95% CI: 2.057~10.318, P<0.001), preoperative sinus tract( OR=6.115, 95% CI: 2.630~14.220, P<0.001) and multiple bacterial mixed infection( OR=2.600, 95% CI: 1.131~5.977, P=0.020) were risk factors for DAIR failure; Kaplan-Meier survival curve also confirmed that the patients with Staphylococcus infection, multiple bacterial mixed infection, duration of symptoms over 3 weeks, or preoperative sinus tract had a significantly lower rate of survival than their controls ( P<0.05). Conclusions:For acute PJI, DAIR can be used to retain the prosthesis and control infection. However, DAIR is not recommended for the patients with Staphylococcus aureus infection, multiple bacterial mixed infection, symptoms lasting more than 3 weeks, or preoperative sinus formation.

Prediction Method of Elastic Modulus of Trabecular Bone Based on SE-DenseVoxNet / 中国医疗器械杂志

Osteoporosis is one of the common metabolic diseases, which can easily lead to osteoporotic fractures. Accurate prediction of bone biomechanical properties is of great significance for the early prevention and diagnosis of osteoporosis. Bone mineral density measurement is currently used clinically as the gold standard for assessing bone strength and diagnosing osteoporosis, but studies have shown that bone mineral density can only explain 60% to 70% of bone strength changes, and trabecular bone microstructure is an important factor affecting bone strength. In order to establish the connection between trabecular bone microstructure and bone strength, this paper proposes a prediction method of trabecular bone modulus based on SE-DenseVoxNet. This method takes three-dimensional binary images of trabecular bone as input and predicts its elastic modulus in the z-axis direction. Experiments show that the error and bias between the predicted value of the method and the true value of the sample are small and have good consistency.

Advances in the study of early ambulation situation and impediments to implementation among postoperative patients undergoing Total Hip and Knee Arthroplasty / 中国实用护理杂志

With the rapid development of an aging society, the number of Total Hip and Knee Arthroplasty continues to increase, which makes the country medical insurance funds and elderly patients burden with medical treatment increasing. The early ambulation of postoperative patients with Total Hip and Knee Arthroplasty can effectively shorten the length of hospital stay, save hospitalization costs, and improve joint function. Therefore, this article reviews the concept, status, implementation obstacles, promotion measures and other aspects of early ambulation of postoperative patients undergoing Total Hip and Knee Arthroplasty, with a view to provide theoretical reference for the development of standar-dized and efficient early ambulation of medical personnel.

Patient satisfaction survey after anterior cruciate ligament reconstruction / 中国组织工程研究

BACKGROUND:There are many methods for evaluating anterior cruciate ligament reconstruction. However, doctors always like to assess the outcome with the objective criteria, such as range of motion and imaging examinations, and patient satisfaction is little considered.OBJECTIVE:To explore the factors that may influence the patient satisfaction after anterior cruciate ligament reconstruction. METHODS:Ninety-eight patients undergoing anterior cruciate ligament reconstruction were enroled, including 58 male and 40 female patients, and the average age was 27.4 years old. All patients were followed up (average 17.5 months) to investigate the patient satisfaction. The factors related to the satisfaction were analyzed, such as age, follow-up time, sex, injured knee, mental health, education, economic situation, postoperative athletic ability, and International Knee Documentation Committee scores. RESULTS AND CONCLUSION:After the follow-up, 72.4% patients said that they were satisfied with the outcome, and 27.6% dissatisfied with the outcome. The mental health, economy situation, postoperative athletic ability, and International Knee Documentation Committee scores were significantly related to the patient satisfaction (P < 0.05). To conclude, improved living and medical standard, intensive communication and psychological counseling, as well as rational postoperative rehabilitation scheme can improve the patient satisfaction after anterior cruciate ligament reconstruction.

Early clinical outcomes of anterior cruciate ligament reconstruction by LARS artificial ligament versus hamstring tendon autograft / 医学研究生学报

Objective Clinically, the anterior cruciate ligament ( ACL) can be reconstructed by either ligament advanced reinforcement system ( LARS) artificial ligament or hamstring tendon autograft ( HTAG) . This study aims to compare the early clinical outcomes of LARS versus HTAG in the treatment of ACL. Methods This study included 38 cases of ACL injury treated in our de-partment from March 2012 to August 2014, 18 by LARS artificial ligament and the other 20 by HTAG. Before and at 18 months after surgery, we evaluated the clinical outcomes of the tow strategies using the Lysholm knee scoring scale and International Knee Documen-tation Committee ( IKDC) scoring systems, and conducted statistical analysis on the follow-up findings. Results Statistically signifi-cant differences were not observed preoperatively between the LARS and HTAG groups either in the Lyshrolm scores (46.78±1.52 vs 46.80 ±1.89, P>0.05) or in the IKDC scores (42.83±1.47 vs 42.20±1.61, P>0.05), nor at 18 months postoperatively in the Lyshrolm scores (93.52±3.19 vs 94.10±1.37, P>0.05) or the IKDC scores (92.11± 1.45 vs 93.15±1.76, P>0.05). However, both the LARS and HTAG groups showed significant differences in the Lyshrolm and IKDC scores at the baseline as compared with those at 18 months after oper-ation ( P<0.05) . Conclusion Both LARS artificial ligament ham-string tendon autograft can achieve good early clinical outcomes in ACL reconstruction.

Advances on treatment of Bankart lesions / 医学研究生学报

The shoulder joint is the largest joint of range of motion in the human body,but the stability is relatively low.Ath-letes and soldiers who engage in the high strength training are prone to shoulder joint instability, while Bankart lesion is the common factor which leads to shoulder joint instability.With the invention of the new medical devices and updating therapeutic method, the treatment of Bankart lesions is improved continuously.In this paper, we will review the key points of diagnosis and therapeutic method.

Semaphorin7A intervention for titanium particles-induced apoptosis in mouse MC3T3-E1 osteoblasts / 中国组织工程研究

BACKGROUND:Semaphorin7A (Sema7A) is a kind of cel surface protein, which can promote the fusion of osteoclasts and the migration of osteoblasts at the same time, affecting the dynamic balance of the bone. It is speculated that Sema7A siRNA may inhibit osteoblast apoptosis induced by titanium particles. OBJECTIVE:To study the effect of Sema7A on the preosteoblast activity inhibited by titanium particles. METHODS:Mouse MC3T3-E1 preosteoblasts at passages 6 and 7 were divided into four groups: in blank control group, MC3T3-E1 cels were cultured alone; in standard control group, cel were cultured with titanium particles; in experimental groups 1 and 2, the cels were cultured with titanium particles+Sema7A overexpression plasmids and titanium particles+Sema7A siRNA, respectively. Apoptotic rate of MC3T3-E1 cels was detected by flow cytometry; the mRNA expression of bone sialoprotein, osteocalcin and type I colagen was detected by Q-PCR; western blot assay was adopted to detect the protein expression of bone sialoprotein, osteocalcin and type I colagen; alizarin red calcium nodule staining was taken to detect the degree of osteoblast mineralization. RESULTS AND CONCLUSION:The expressions of bone sialoprotein, osteocalcin and type I colagen were decreased in the standard control group and experimental group 1, but these expression were significantly increased in the experimental group 2 compared with the standard control group (P < 0.05). Flow cytometry results suggested that the apoptotic rate of osteoblasts in the experimental group 1 was significantly higher than that in the other groups (P < 0.05), and the apoptotic rate in the experimental group 2 was lower than that in the standard control group (P < 0.05). Alizarin red staining showed that there were no obvious mineralized nodules in the experimental group 1, but mineralized nodules formed in the experimental group 2. In brief, the genetic interference technique that inhibits the activity of Sema7A can interfere the process of mouse MC3T3-E1 preosteoblast differentiation inhibited by titanium particles, and thus provide a feasible way for the clinical treatment of wear particles-induced osteolysis using biotechnology.

Study advancement of antioxidants on preventing tendon adhesion / 医学研究生学报

Tendon adhesion easily occurs after the operation.The outcome of tendon repair can be affected by adhesion, in-terfering with their normal gliding function.With increasingly deepened konwledge of the tendon healing process and continuous devel-opment of sciences related to medicine, a variety of effective approaches are provided to prevent tendon adhesion.Antioxidants are new orientations that are provided for prevention of tendon adhesion.Although most researches are only limited to animal experiments, the outcomes are positive.This paper reviews the mechanisms and relevant characteristics of tendon adhesion prevention in order to have a better understanding on the roles of antioxidants for preventing tendon adhesion.

Bone microstructure and cement-bone interfacial biomechanics of tibial plateau of osteoarthritis and rheu-matoid arthritis / 医学研究生学报

Objective Bone cement joint prosthetic aseptic loosening always occurs in the bone cement-bone interface, while the mechanical strength of the interface mainly depends on the microstructure and adhesive strength.The aim of this study was to ex-plore the bone microstructure and the cement bone interfacial biomechanics of osteoarthritis(OA) and rheumatoid arthritis(RA), and also discuss the correlation. Methods Twenty trabecular bone specimens of tibial plateaus were taken from OA and RA patients who underwent total knee arthroplasty( TKA) .The microstructural parameters of the trabecular bone specimens were measured by Skyscan1176 microcomputed tomography.The bone specimens were made into cementbone models, which were tested by INSTRON strength tester.The association of bone microstructure and interfacial shear stress was analyzed subsequently. Results ①Bone volume fraction ( BV/TV) ( r=-0.313) , trabecular thickness ( Tb.Th) ( r=-0.340) ,trabecular spacing ( Tb.Sp) ( r=0.345) of OA had obvious correlation to shear strength (P<0.05).The cement-bone interfacial strength of medial tibial plateaus[(87.45±52.50)N] was lower than lateral tibial plat-eaus[(177.25±71.11)N] of OA (P<0.05).②Bone volume fraction (BV/TV)(r=0.343), trabecular number (Tb.N)(r=0.391) of RA had obvious correlation to shear strength (P<0.001).The cement-bone interfacial strength of lateral tibial plateaus[(62.23±46.22) N] was lower than medial tibial plateaus[(79.20±56.37N)] of RA (P<0.05).③The interfacial strength of OA[(132.35±76.64)N] was higher than RA[(71.05±51.55)N] (P<0.05). Conclusion There are differences of microstructure between OA and RA, which lead to the distinction of strength of cement -bone interface.And it has a certain guiding role of analyzing the biomechanics in TKA.

Advances in bioscaffolds applications repaired rotator cuff injury / 医学研究生学报

Rotator cuff tears is a common cause of debilitating pain, reduced shoulder function, and weakness.Although the research progress for rotator cuff tear and surgical treatment has made great progress, rotator cuff repair failure rate still was ranged from 20 to 90%.Therefore it need new repair materials which can effectively improve the mechanical strength and stimulateg the intrinsic healing potential of the patient.In recent years, biological scaffolds used in rotator cuff repair has become a hotspot.This paper reviews the progress of scaffold materials on the treatment of rotator cuff injury.

Diagnosis and treatment of medial plica syndrome of the knee by arthroscopy:Analysis of 46 cases / 医学研究生学报

Objective With the emerging omnipresence of arthroscopy, the plica syndrome has achieved a clinical recogni-tion as a pathological entity .This study is to investigate the clinical diagnosis and treatment of the medial plica syndrome of the knee . Methods We retrospectively analyzed 198 cases of medial plica syndrome, internal semilunar cartilage and chondromalacia patellae in the knee joints treated in our department from January 2008 to December 2011 .All the patients received physical and MRI examina-tions before admission and underwent plicaectomy, their knee function evaluated according to their Lysholm scores pre-and post-opera-tively. Results The diseased plica synovialis was completely excised in 46 cases diagnosed as simple medial plica syndrome by ar-throscopy.Forty-four of the patients were followed up for 6 to 32 (mean 26) months, and the excellence rate of treatment result was 95.5%. Conclusion Medial plica syndrome of the knee constitutes a larger proportion of knee disorders, for which arthroscopy re-mains the best diagnostic option and total excision of the diseased plica synovialis is an effective treatment .

Progress on the mechanism and repair of the rotator cuff injury / 医学研究生学报

The rotator cuff injury may be associated with subacromial impingement , ischemic degeneration , abnormal biome-chanical factors, However, depending on the size and type of repair , acute or chronic injury , can need different repair methods .Under the influence of various factors , traditional repair methods have the lower success rate for rotator cuff injury .With deeply understanding the mechanism of injury and the development of tissue engineering and materials science , the treatment of rotator cuff injury may get the better results with the use of new materials .

Inhibitory effect of Sema7A siRNA on osteoclast activation induced by titanium particles / 中国组织工程研究

BACKGROUND:Sema7A is a kind of cel surface protein, which can promote the fusion of osteoclasts and the migration of osteoblast at the same time, affecting the dynamic balance of bone. OBJECTIVE:To investigate whether Sema7A siRNA has ainhibitory effect on the osteoclast activation in the process of osteolysis which induced by titanium particles. METHODS:The precursor osteoclasts with the concentration of 4×109 RESULTS AND CONCLUSION:At 7 days of culture, the expression levels of interleukin-1, interleukin-1β, tumor necrosis factor α, matrix metaloproteinase-9 and the receptor activator of nuclear factor-κB in the positive control, /L were seeded on 96-wel plates containing glass cover slips, and divided into four groups: blank control, positive control, experiment and negative control groups. The cel culture medium was added into the control group. 20 μL un-transfected siRNA supernatant was added into the positive control group. 20 μL transfected Sema7A siRNA supernatant was added into the experiment group. 20 μL transfected control siRNA supernatant was added into the negative control group. The supernatant was obtained through the co-culture between titanium particles solution and monocyte-macrophage cel line RAW264.7of mouse for 24 hours. siRNA was transfected into mononuclear macrophage cel lines RAW264.7 of mice. negative control and experiment groups were higher than those in the control group (P < 0.05). The expression level of each factor in the experiment group was lower than that in the positive control and negative control groups (P < 0.05). At 8 days of culture, the proliferation activity of osteoclasts and the number of positive cels stained by tartrate-resistant acid phosphatase in the positive control, negative control and experiment groups were higher than those in the control group (P < 0.05). The proliferation activity of osteoclasts and the number of positive cels stained by tartrate-resistant acid phosphatase in the experiment group were lower than those in the control and negative groups (P < 0.05). These results demonstrate that Sema7A siRNA has a certain inhibitory effect on the osteoclast activation induced by titanium particles.

Effects of tranexamic acid on hidden blood loss after total knee arthroplasty in animal models / 中国组织工程研究

BACKGROUND:Hidden blood loss leads to severe anemia after orthopedic joint arthroplasty.Blood transfusion is needed.Use of tranexamic acid can significantly decrease perioperative blood loss,reduce blood transfusion rate,however,mechanism of action of tranexamic acid on hidden blood loss and its relevance are not clear.OBJECTIVE:By establishing the rabbit models of total knee prosthesis,this study was designed to observe thevariation of early preoperative blood loss with tranexamic acid,and to study the effects of tranexamic acid on hidden blood loss and its influence on deep venous thrombosis of lower limb.METHODS: We designed the rabbit knee prosthesis ourselves.A total of 20 adult New Zealand rabbits were randomly divided into two groups,each group with 10 rabbits.Knee arthroplasty on the same side was performed.Experimental group received intravenous injection of 0.5 g 100 mL tranexamic acid at 15 minutes before replacement.Control group was given 100 mL sodium chloride at the same time.Blood was colected from al animals through ear vein at 1 day before replacement,3,6,24,48,72 hours and 7 days after replacement.Blood routine examination and blood coagulation function test were conducted.The content of plasma D-Dimer was determined.Simultaneously,the operation time and intraoperative bleeding amount were recorded.After replacement,lower limb venous ultrasonography was performed.RESULTS AND CONCLUSION: No significant difference in body weight,hemoglobin,hematocrit,and D-Dimer levels was detected between the two groups before replacement (P＞0.05).Significant differences in operation time and intraoperative dominant blood loss were detectable between the two groups (P＜0.05).Significant differences in hemoglobin and hematocrit were detected at 24 hours after replacement (P＜ 0.05),and these were better in the experimental group than in the control group.No significant difference in D-Dimer was observed between the two groups after replacement (P＞ 0.05).Operation time and intraoperative dominant blood loss were significantly associated with hemoglobin and hematocrit at 24 hours after replacement (P＜0.05).The changes in hemoglobin and hematocrit at 72 hours and 7 days after replacement were not apparently correlated with intraoperative D-Dimer changes.Obvious thrombus was not seen by lower limb venous ultrasonography after replacement.These results indicated that the use of tranexamic acid before total knee arthroplasty apparently reduced the intraoperative dominant blood loss,shortened operation time,and noticeably decreased hidden blood loss at 1 day after replacement,which was caused by the increased fibrinolysis with surgical stress,and did not apparently impact other hidden blood loss induced by other mechanism.Simultaneously,tranexamic acid is safe and reliable,and does not increase the risk of perioperative thrombus.

Semaphorins play an important role in bone homeostasis and metabolic bone disease / 中国组织工程研究

BACKGROUND:Bone formation is a dynamic process, and osteoclasts and osteoblasts are involved in this dynamic process. Semaphorins were found first as axonal growth cone guidance molecules, which express in many different tissues and regulate many physiological processes. Recently, Semaphorins are confirmed to play an important role in the regulation of osteoclasts and osteoblasts. OBJECTIVE:To summarize the role of Semaphorins in bone homeostasis. METHODS: A computer-based search of PubMed and Web of Science was performed for articles related to the effect of Semaphorins in regulation of bone metabolism published from June 1993 to January 2014 using the keywords of “semaphorin, sema”. Irrelevant articles or duplicate content articles were excluded, and finaly 48 articles were reviewed. RESULTS AND CONCLUSION:Semaphorins act as a new class of regulatory molecules in the aspect of bone cytobiology. Studies have show semaphorins are actively involved in bone remodeling through some special mechanisms, and semaphorin proteins are crucial for bone homeostasis, which provides a new method and therapeutic target for the treatment of osteoporosis, bone sclerosis, osteolysis adjacent to joint prosthesis and other bone diseases.

Intravenous drip and topical application using tranexamic acid decrease hidden blood loss after total hip arthroplasty / 中国组织工程研究

BACKGROUND:Tranexamic acid has been more and more used in reducing bleeding after joint replacement, but its usage method and dosage remain controversial, and become a hot focus in recent years. OBJECTIVE: To investigate the efficacy and safety of intravenous drip combined with intra-articular injection of tranexamic acid on postoperative hidden blood loss in patients who received primary total hip arthroplasty. METHODS:Clinical data of 65 patients undergoing primary total hip arthroplasty were randomized to the test group and the control group. The patients in the test group received 0.5 g tranexamic acid through intravenous drip when the surgery starts and 0.5 g tranexamic acid inside hip joint through a drainage tube after capsule closure, and retaining for 6 hours. The patients in the control group intravenously received the same volume of physiological saline, and 50 mL physiological saline through a drainage tube after suture, and retaining for 6 hours. We compared with intraoperative blood loss, postoperative dominant blood loss and hidden blood loss, pain score, blood transfusion rate, deep vein thrombosis and day of hospitalization in both groups. RESULTS AND CONCLUSION:Hemoglobin and hematocrit were higher in the test group than in the control group after replacement (P 0.05). These results indicate that the intravenous drip combined intra-articular injection of tranexamic acid in patients receiving total hip arthroplasty could reduce the amounts of postoperative dominant and hidden blood loss and blood transfusion rate, and did not increase the incidence of deep vein thrombosis.

Risk factors and prognosis of perioperative hidden blood loss in hip replacement patients / 中国组织工程研究

BACKGROUND:Hidden blood loss, a frequent occurrence fol owing artificial joint replacement, greatly affects the recovery from total hip arthroplasty. Many factors have been shown to have a correlation with the hidden blood loss, but the specific mechanism is not yet clear. OBJECTIVE:To investigate the correlation of patients’ baseline (sex, age, underlying disease, obesity), prosthesis types, surgical time with hidden blood loss fol owing total hip arthroplasty, as wel as the association between hidden blood loss and prognosis. METHODS:Ninety patients undergoing total hip arthroplasty were enrol ed in this study. Using Gross formula, we calculated the total blood loss according to height, weight, and pre-and post-operative hematocrit, and subtracted the dominant loss of blood to get the quantitative value of hidden blood loss. According to the criterion, the 90 patients were divided to two groups:group I:volume of hidden blood loss>480 mL, group II:volume of hidden blood loss RESULTS AND CONCLUSION:There were 39 patients in the group I, including 64.1%males, 64.1%hypertension patients, 35.9%diabetic patients, 7.7%patients receiving cement prosthesis;while, there were 51 patients in the group II, including 37.3%males, 25.5%hypertension patients, 5.9%diabetic patients, 35.3%patients receiving cemented prosthesis, showing a significant difference between the two groups. Based on these experimental findings, age, hypertension, diabetes mel itus, type of prosthesis were shown to be factors independently associated with hidden blood loss;however, obesity and smoking exhibited no correlation with hidden blood loss. In addition, a statistical difference in the survival rate was found at admission and during the 1-year fol ow-up.

Effects of PI3K/Akt signaling pathway on the proliferation and cell cycles of MC3T3-E1 cells / 医学研究生学报

Objective Recent studies show that the PI3K/Akt signaling pathway is a key regulatory signal in both bone for-mation and bone remodeling .The experiment aimed to investigate the effects of inhibiting the PI 3K/Akt signaling pathway on the prolif-eration and cell cycles of MC3T3-E1 cells. Methods We treated MC3T3 -E1 cells with PF-04691502 the inhibitor of the PI3K/Akt signaling pathway .Then we determined the proliferative activity of the cells by MTS assay , detected the cell cycles by flow cytometry , and measured the expression of cell cycle-related proteins by Western blot . Results After inhibition of the PI3K/Akt signaling path-way with PF-04691502 at 30, 150 and 750 nmol/L, the proliferation of MC3T3-E1 cells was reduced in a dose-dependent manner to 0.647 ±0.041, 0.423 ±0.011 and 0.159 ±0.004, respectively, as compared with 1 ±0.056 in the control group (P<0.01).Sim-ultaneously , the percentage of the cells in the sub-G1 phase was significantly higher in the 1 μmol/L group than in the control ([1.45 ±0.43]%vs [0.27 ±0.21]%, P<0.01) and the expression of cyclin D1 was decreased. Conclusion Inhibition of the PI3K/Akt signaling pathway can block MC 3T3-E1 cells in the sub-G1 phase and reduce the proliferation of the cells .