ObjectiveTo investigate the effect of tissue interface stiffness change on the spreading, proliferation, and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs), and to find the suitable stiffness range for stem cell differentiation. MethodsBone marrow of male Sprague Dawley rats (4 weeks old) were selected to isolate and culture BMSCs by whole bone marrow cell adherent method. The third generation BMSCs (1×105 cells/mL) were inoculated into the ordinary culture dishes covered with polyacrylamide hydrophilic gel (PA) which elastic modulus was 1, 4, 10, 40, and 80 kPa (cells seeded on PA), and ordinary culture dish (75 MPa extreme high elastic modulus) as control. Spreading of cells in different stiffness of PA was observed under light microscope. The elastic modulus values of 4, 10, and 40 kPa PA were selected as groups A, B, and C respectively; the ordinary culture dish (75 MPa extreme high elastic modulus) was used as control group (group D). Cell counts was used to detect the growth conditions of BMSCs, alkaline phosphatase (ALP) kit to detect the concentration of ALP, alizarin red staining technique to detect calcium deposition status, and real-time quatitative PCR technique to detect the expressions of bone gla protein (BGP), Runx2, and collagen type I mRNA. ResultsWith increased PA stiffness, BMSCs spreading area gradually increased, especially in 10 kPa and 40 kPa. At 1 and 2 days after culture, the growth rate showed no significant difference between groups (P > 0.05); at 3-5 days, the growth rate of groups B and C was significantly faster than that of groups A and D (P < 0.05), but difference was not statistically significant between groups A and D (P < 0.05); at 5 days, the proliferation of group C was significantly higher than that of group B (P < 0.05). ALP concentrations were (53.69±0.89), (97.30±1.57), (126.60±14.54), and (12.93±0.58) U/gprot in groups A, B, C, and D respectively; groups A, B, and C were significantly higher than group D, and group C was significantly higher than groups A and B (P < 0.05). Alizarin red staining showed that the percentages of calcium nodules was 20.07%±4.24% in group C; group C was significantly higher than groups A, B, and D (P < 0.05). The expression levels of BGP and collagen type I mRNA were significantly higher in groups A, B, and C than group D, and in group C than groups A and B (P < 0.05). The expression level of Runx2 mRNA was significantly higher in groups B and C than group D, and in group C than group B (P < 0.05), but no significant difference was found between groups A and D (P > 0.05). ConclusionPA elastic modulus of 10-40 kPa can promote the proliferation and osteogenic differentiation of BMSCs, and the higher the stiffness, the stronger the promoting effect.
Idiopathic pulmonary fibrosis (IPF) is a progressive scar-forming disease with a high mortality rate that has received widespread attention. Epithelial mesenchymal transition (EMT) is an important part of the pulmonary fibrosis process, and changes in the biomechanical properties of lung tissue have an important impact on it. In this paper, we summarize the changes in the biomechanical microenvironment of lung tissue in IPF-EMT in recent years, and provide a systematic review on the effects of alterations in the mechanical microenvironment in pulmonary fibrosis on the process of EMT, the effects of mechanical factors on the behavior of alveolar epithelial cells in EMT and the biomechanical signaling in EMT, in order to provide new references for the research on the prevention and treatment of IPF.
ObjectiveTo compare the biomechanical characteristics of self-made nickel-titanium shape memory alloy stepped plate with calcaneal plate and cannulated compression screws in fixing calcaneal osteotomy.MethodsCalcaneal osteotomy was operated on 6 fresh-frozen lower limbs collected from donors. Then three kinds of fixation materials were applied in random, including the self-made nickel-titanium shape memory alloy stepped plate (group A), calcaneal plate (group B), and cannulated compression screws (group C). Immediately after fixation, axial loading of 20-600 N and 20 N/s in speed was introduced to record the biomechanical data including maximum displacement, elastic displacement, and maximum load. Then fatigue test was performed (5 Hz in frequency and repeat 3 000 times) and the same axial loading was introduced to collect the biomechanical data. Finally, the axial compression stiffness before and after fatigue test were calculated.ResultsThere was no significant difference in the axial compression stiffness between pre- and post-fatigue test in each group (P>0.05). However, the axial compression stiffness was significant higher in group A than that in groups B and C both before and after fatigue test (P<0.05). No significant difference was found between group B and group C (P>0.05).ConclusionSelf-made nickel-titanium shape memory alloy stepped plate is better than calcaneal plate and cannulated compression screws in axial load stiffness after being used to fix calcaneal osteotomy.
OBJECTIVE: Extension stiffness of knee joint is always treated by the quadricepsplasty, but the main deficiency of this method is that patient feels weakness of lower limb and easily kneels down. The aim of this article is to explore the method to resolve the complications after quadricepsplasty. METHODS: Since 1978 to 1997, on the basis of traditional procedures of quadricepsplasty, sartorius muscle was used to reinforce the extension of knee joint. The lower 2/3 of sartorius muscle was fully dissociated only with its insertion intact. A tendon-periosteal-bone flap, about 2 cm in width, was managed on the anterior surface of patella, with its pedicle on the medial edge of patella. The tendon-periosteal-bone flap was used to fix the dissociated sartorious into patella to reinforce the extension of knee joint. The very lower part of sartorius was mainly aponeurosis, with the help of an aponeurosis bundle of iliotibial tract, it was fixed into the insertion of patellar ligament, through a bony tunnel chiseled adjacent to the insertion of patellar ligament. By now the movement of knee joint extension was strengthened by the transferred sartorius muscle. Postoperatively, every patient was required to extend and flex knee joint actively and/or passively. Altogether 12 patients were treated, 9 of them were followed up with an average of 14 months. RESULTS: The average movement was increased from 15 degrees to 102 degrees, and the average myodynamia was improved from grade II to grade IV. CONCLUSION: Traditional quadricepsplasty co-operated with transfer of sartorius muscle can strengthen the myodynamia of knee joint extension. It is simple method and can really achieve good function.
ObjectiveTo observe the changes of plasma homocysteine (Hcy) and brachial ankle pulse wave velocity (baPWV) in patients with subclinical hypothyroidism, and discuss the relationship between subclinical hypothyroidism and arterial stiffness. MethodSeventy-three patients with subclinical hypothyroidism who were not treated before were divided into two groups according to thyroid stimulating hormone (TSH) level between January 2013 and June 2014. There were 35 patients in group A (4 mU/L < TSH < 10 mU/L) and 38 in group B (TSH ≥ 10 mU/L). Another 30 healthy individuals were selected as controls. Hcy and baPWV were determined in all subjects. ResultsCompared with the controls, patients had significantly higher level of TSH, Hcy and baPWV in group A, and had significantly higher TSH, triacylglycerol (TG), low density lipoprotein cholesterol (LDL)-C, Hcy, and baPWV in group B (P<0.05). Compared with group A, TSH, TG, LDL-C, Hcy, and baPWV in group B patiens were significantly higher (P<0.05). Pearson correlation analysis showed that Hcy was positively correlated with TSH (r=0.353, P<0.01) and baPWV was positively correlated with TSH (r=0.416, P<0.01). ConclusionsHcy level and peripheric arterial stiffness increase in patients with subclinical hypothyroidism. Both of them are correlated positively with TSH.
Objective To explore the effectiveness of computer-aided technology in the treatment of primary elbow osteoarthritis combined with stiffness under arthroscopy. Methods The clinical data of 32 patients with primary elbow osteoarthritis combined with stiffness between June 2018 and December 2020 were retrospectively analyzed. There were 22 males and 10 females with an average age of 53.4 years (range, 31-71 years). X-ray film and three-dimensional CT examinations showed osteophytes of varying degrees in the elbow joint. Loose bodies existed in 16 cases, and there were 7 cases combined with ulnar nerve entrapment syndrome. The median symptom duration was 2.5 years (range, 3 months to 22.5 years). The location of bone impingement from 0° extension to 140° flexion of the elbow joint was simulated by computer-aided technology before operation and a three-dimensional printed model was used to visualize the amount and scope of impinging osteophytes removal from the anterior and posterior elbow joint to accurately guide the operation. Meanwhile, the effect of elbow joint release and impinging osteophytes removal was examined visually under arthroscopy. The visual analogue scale (VAS) score, Mayo elbow performance score (MEPS), and elbow range of motion (extension, flexion, extension and flexion) were compared between before and after operation to evaluate elbow function. Results The mean operation time was 108 minutes (range, 50-160 minutes). All 32 patients were followed up 9-18 months with an average of 12.5 months. There was no other complication such as infection, nervous system injury, joint cavity effusion, and heterotopic ossification, except 2 cases with postoperative joint contracture at 3 weeks after operation due to the failure to persist in regular functional exercises. Loose bodies of elbow and impinging osteophytes were removed completely for all patients, and functional recovery was satisfactory. At last follow-up, VAS score, MEPS score, extension, flexion, flexion and extension range of motion significantly improved when compared with preoperative ones (P<0.05). Conclusion Arthroscopic treatment of primary elbow osteoarthritis combined with stiffness using computer-aided technology can significantly reduce pain, achieve satisfactory functional recovery and reliable effectiveness.
ObjectiveAntiviral treatments could benefit chronic hepatitis B (CHB) patients with the regression or improvement of liver fibrosis. However, the degree of dynamic change of liver fibrosis for patients who had not received antiviral treatment remained to be studied. The current study aimed to observe the long-term variation of liver stiffness measurement (LSM), virological and biochemical response on patients without standard antiviral therapy.MethodsA total of 220 patients who were diagnosed with chronic HBV infection, who had not reached the standard of antiviral therapy, and completed a follow-up date of over 2 years in the First Affiliated Hospital of Xi’an Jiaotong University from 2012 to 2018 were retrospectively enrolled. According to the changes of LSM in baseline and follow-up period, the patients were divided into regression group, non-progressive group, and progressive group. The virological and biochemical characteristics of each group were analyzed.ResultsAmong the 220 patients, 153 patients (69.5%) had no progress in LSM degree. Alanine aminotransferase (ALT), HBV DNA, and HBsAg in a few patients increased or slightly decreased, while the vast majority remained in a relatively stable state. 89.5% (137/153) of the non-progressive patients were in grade F0. In addition, 58 patients showed spontaneous improvement with a decreasing rate of 0.460 kPa per year. Patients with ALT of 1-2 ULN had a statistically significant decrease in LSM improvement compared to patients with normal ALT. 82.8% of the LSM-improving patients showed baseline LSM of F1-F3. Only 9 patients showed LSM deterioration, however, which could not be explained by virus replication or necroinflammatory activity. ConclusionsFor patients unsatisfying standard antiviral therapy, most patients with baseline LSM of F0 grade fail to progress, and patients with baseline LSM of F1-F3 show a decrease during follow-up, LSM progression occurs in 4.1% of patients.
The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.
Objective To evaluate the results of open arthrolysis by elevated the lateral and medial collateral l igament-musculature complex from the supracondylar ridge of the humerus in treatment of post-traumatic elbow stiffness. Methods From March 2003 to December 2007, 33 patients with post-traumatic elbow stiffness were treated with open arthrolysis by elevated the lateral and medial collateral l igament-musculature complex from the supracondylar ridge of the humerus. There were 23 males and 10 females, aged 17-70 years old (mean 41.8 years old). According to Morrey, 15 caseswere extremely serious (less than 30° extension-flexion arc) and 18 cases were serious (30-60° extension-flexion arc). The range of motion of the elbow stiffness was (32.5 ± 28.9)° and the Mayo score was 51.9±13.1 before operation. All initial fractures were healed according to cl inical examination and X-rays films. All patients present with a post-traumatic elbow stiffness and the average period from initial trauma to elbow arthrolysis was 16.9 months (2-72 months). Results Wound infection occurred in 1 patient and cured after dressing change and anti-infectious treatment. The wounds healed by first intension in 32 cases. No patient showed sign of elbow instabil ity and debil itating pain. All patients were followed up 6 months to 5 years (mean 3.3 years). At last follow up, the Mayo score was 82.3 ± 14.4 and the range of motion of elbow stiffness was (108.8 ± 36.0)°; showing significant differences when compared with preoperation (P lt; 0.05). According to Mayo evaluation, the results were excellent in 11 cases, good in 18 cases, fair in 2 cases, and poor in 2 cases, the excellent and good rate was 87.88%. Thirty-one patients achieve satisfactory results. Two patients were not satisfied with the result, but the satisfactory results were achieved by a second arthrol ysis. Conclusion Open elbow arthrolysis and postoperative rehabil itation for patients with elbow stiffness can improve joint function and ensure the stabil ity of elbows.
ObjectiveTo investigate the relationship between pulmonary ventilation function (obstructive and restrictive ventilation dysfunction) and atherosclerosis, and explore the correlation between brachial-ankle pulse wave velocity (ba-PWV, an effective index for evaluating atherosclerosis) and pulmonary ventilation function.MethodsFrom January to August 2018, a total of 6403 healthy subjects who reported no major chronic diseases such as stroke, myocardial infarction, cor pulmonale or malignant tumor were selected. Past history such as smoking history, hypertension, diabetes, blood biochemistry, and blood hypersensitive C reactive protein (hs-CRP), hemodynamic indexes such as systolic pressure, diastolic pressure and ba-PWV, body measurement indexes such as height, weight, waist circumference and pulmonary ventilation function were collected. The relationship between ba-PWV and pulmonary ventilation function were evaluated.ResultsA total of 2433 subjects were included, including 916 males and 1517 females. Ba-PWV showed significant positive correlations with age, smoking index, waist circumference, systolic blood pressure, diastolic blood pressure, triglyceride, cholesterol, low density lipoprotein, hs-CRP, glycosylated hemoglobin, and significant negative correlations with height, percentage of forced vital capacity (FVC) in the predicted value (FVC%pred), forced expiratory volume in one second (FEV1), percentage of FEV1 in the predicted value (FEV1%pred), FEV1/FVC ratio and percentage of maximun midexpiratory flow (MMEF) in the predicted value (MMEF%pred). The ba-PWV was not correlated with weight, body mass index, FVC, MMEF, γ-glutamyl transpeptidase, high density lipoprotein, creatinine or uric acid. In multiple regression analysis using factors other than ba-PWV and respiratory function as adjustment variables, both FVC%pred and FEV1%pred showed significant negative relationships with ba-PWV (P<0.05).ConclusionsThe results indicate that FEV1/FVC, an indicator of airflow limitation, is not a predictor of ba-PWV. However, since ba-PWV showed significant negative relationship with FVC%pred and FEV1%pred, clinically assessment of arterial stiffness might be considered in individuals with impaired pulmonary ventilation.