Variability of BMP-2 content in DBM products derived from different long bone.

Demineralized bone matrix (DBM) has been regarded as an ideal bone substitute as a native carrier of bone morphogenetic proteins (BMPs) and other growth factors. However, the osteoinductive properties diverse in different DBM products. We speculate that the harvest origin further contributing to variability of BMPs contents in DBM products besides the process technology. In the study, the cortical bone of femur, tibia, humerus, and ulna from a signal donor were prepared and followed demineralizd into DBM products. Proteins in bone martix were extracted using guanidine-HCl and collagenase, respectively, and BMP-2 content was detected by sandwich enzyme-linked immunosorbent assay (ELISA). Variability of BMP-2 content was found in 4 different DBM products. By guanidine-HCl extraction, the average concentration in DBMs harvested from ulna, humerus, tibia, and femur were 0.613 ± 0.053, 0.848 ± 0.051, 3.293 ± 0.268, and 21.763 ± 0.344, respectively (p < 0.05), while using collagenase, the levels were 0.089 ± 0.004, 0.097 ± 0.004, 0.330 ± 0.012, and 1.562 ± 0.008, respectively (p < 0.05). In general, the content of BMP-2 in long bones of Lower limb was higher than that in long bones of upper limb, and GuHCl had remarkably superior extracted efficiency for BMP-2 compared to collagenase. The results suggest that the origin of cortical bones harvested to fabricate DBM products contribute to the variability of native BMP-2 content, while the protein extracted method only changes the measured values of BMP-2.

The Cell Envelope Integrity Protein Homologue D0Y85_RS06240 of Stenotrophomonas Confers Multiantibiotic Resistance.

Background: The potential role of cell envelope integrity proteins in mediating antibiotic resistance is not well understood. In this study, we investigated whether the cell envelope integrity protein D0Y85_RS06240 from the multiantibiotic resistant strain Stenotrophomonas sp. G4 mediates antibiotic resistance. Methods: Bioinformatics analysis was conducted to identify proteins related to the D0Y85_RS06240 protein. The D0Y85_RS06240 gene was heterologously expressed in Escherichia coli, both antibiotic MICs and the effect of efflux pump inhibitors on antibiotic MICs were determined by the broth microdilution method. A combination of antibiotic and efflux pump inhibitor was used to investigate bacterial killing kinetics, and binding of D0Y85_RS06240 to antibiotic molecules was predicted by molecular docking analysis. Results: Sequence homology analysis revealed that D0Y85_RS06240 was related to cell envelope integrity proteins. The D0Y85_RS06240 heterologous expression strains were resistant to multiple antibiotics, including colistin, tetracycline, and cefixime. However, the efflux pump inhibitor N-methylpyrrolidone (NMP) reduced the antibiotic MICs of the D0Y85_RS06240 heterologous expression strain, and bacterial killing kinetics revealed that NMP enhanced the bactericidal rate of tetracycline to the drug-resistant bacteria. Molecular docking analysis indicated that D0Y85_RS06240 could bind colistin, tetracycline, and cefixime. Conclusion: The cell envelope integrity protein D0Y85_RS06240 in Stenotrophomonas sp. G4 mediates multiantibiotic resistance. This study lays the foundation for an in-depth analysis of D0Y85_RS06240-mediated antibiotic resistance mechanisms and the use of D0Y85_RS06240 as a target for the treatment of multiantibiotic-resistant bacterial infections.

Repair of tendons treated with peracetic acid-ethanol and gamma irradiation by EDC combined with NHS: a morphological, biochemical and biomechanical study in vitro.

The purpose of this study was to investigate whether 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) combined with n-hydroxysuccinimide (NHS) can repair tendon damage caused by peracetic acid-ethanol and gamma irradiation sterilization. The semitendinosus tendons of 15 New Zealand white rabbits were selected as experimental materials, and the tendons were sterilized in a solution containing 1% (v/w) peracetic acid and 24% (v/w) ethanol. After 15 kGy gamma irradiation sterilization, the tendons were randomly divided into three groups (n = 10). The tendons were repaired with EDCs of 0, 2.5 and 5 mM combined with 5 mM NHS for 6 h, the tendons were temporarily stored at - 80 ± °C. The arrangement and spatial structure of collagen fibers were observed by light microscopy and scanning electron microscopy, the collagen type and collagen crimp period were observed under a polarizing microscope, and the collagen fibril diameter and its distribution were measured by transmission electron microscopy, from which the collagen fibril index and mass average diameter were calculated. The resistance of collagen to enzymolysis was detected by the free hydroxyproline test, and tensile fracture and cyclic loading tests of each group of tendons were carried out, from which the elastic modulus, maximum stress, maximum strain, strain energy density and cyclic creep strain were calculated. The obtained results showed that the gap between loose collagen fibers in the 0 mM control group was wider, the parallel arrangement of tendons in the 2.5 and 5 mM groups was more uniform and regular and the fiber space decreased, the crimp period in the 5 mM group was lower than that in the 0 mM group (P < 0.05), and the concentration of hydroxyproline in the 5 mM group (711.64 ± 77.95 µg/g) was better than that in the control group (1150.57 ± 158.75 µg/g). The elastic modulus of the 5 mM group (424.73 ± 150.96 MPa) was better than that of the 0 mM group (179.09 ± 37.14 MPa). Our results show that EDC combined with NHS can repair damaged tendons after peracetic acid-ethanol and gamma radiation treatment, and 5 mM EDC has better morphological performance, anti-enzymolysis ability and biomechanical properties than 2.5 mM EDC.

Modular intercalary prosthetic reconstruction for malignant and metastatic tumours of the proximal femur.

To illustrate the surgical technique and explore clinical outcomes of the reconstruction for the malignant and metastatic bone tumour of proximal femur with metallic modular intercalary prosthesis. Sixteen patients who underwent modular intercalary prosthetic reconstruction after tumour resection were included from April 2012 and October 2020. Prosthesis and screws parameters, resected bone length and residual bone length, clinical outcomes and survivorship were analyzed. All patients were followed up for an average of 19 months (range 1-74). In our series, 12 patients died of the progression of the primary disease at the final follow-up. The cumulative survivorship since the treatment of proximal femoral metastasis was 78.6% (11 patients) at 6 months and 38.5% (5 patients) at 1 year. The mean MSTS score was 22.25 ± 4.55 among all patients. There were no cases of loosening or breakage of the prostheses, plates or screws, despite the various measurements of prostheses and residual bones. Modular intercalary prosthetic reconstruction was an effective method for malignant tumour of the proximal femur, including the advantages of providing early pain relief, quickly restoring postoperative function, required a short operation time, and preserving the adjacent joints.

The Value of the Frog Lateral View Radiograph for Detecting Collapse of Femur Head Necrosis: A Retrospective Study of 1001 Cases.

Aims: The collapse in femur head necrosis is generally detected by CT or MRI which are not primary routine examination at every follow-up in developing countries. The purpose of this study was to verify the reliability of the frog lateral view radiograph in detecting the collapse of femoral head. Methods: We retrospectively included 1001 hips of 620 patients with femur head necrosis. The anteroposterior view and frog lateral view of X-ray standard radiographs, CT and MRI of patients were collected and simultaneously evaluated by three orthopedists to evaluate the condition of collapse according to the unified standard. The inter-observer reliability of each view of X-ray for detecting the collapse were analyzed through the weighted Cohen's kappa index. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of each evaluation method were also calculated. Results: A moderate or substantial reliability was indicated in the evaluation of frog lateral view radiograph, whereas the anteroposterior view only showed fair or poor reliability. Using the CT or MRI results of collapse as the gold standard, the frog lateral view indicated higher sensitivity and accuracy than the anteroposterior view (sensitivity: 82.8 vs. 64.9%; accuracy: 87.1 vs. 73.9%). The combination of the anteroposterior view and frog lateral view indicated higher reliability than individual views. Conclusion: The frog lateral view radiograph has higher sensitivity and accuracy than anteroposterior view. It is a complementary method to AP view for detecting the collapse in femur head necrosis during the follow-up, which has moderate or substantial inter-observer reliability.

Correlation between body mass index and two-stage revision failure of periprosthetic joint infection following total joint arthroplasty: A systematic review and meta-analysis.

Background: Although the correlation between body mass index (BMI) and two-stage revision failure of periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) have been frequently reported, the results remain controversial. Therefore, the correlation between them was systematically evaluated and meta-classified in this study. Methods: Literature on the correlation between BMI and two-stage revision failure of PJI following TJA was retrieved in PubMed, Embase and Cochrane Library due May 2020. Stata 13.0 software and Cochrane Collaboration Review Manager software (RevMan version 5.3) were applied to data synthesis, subgroup analysis, analyses of publication bias, and sensitivity. Results: A total of 15 observational studies included 1267 patients, of which 15 studies were included in systematic review and 11 studies in meta-analysis. Eight studies found a correlation between BMI and two-stage revision failure of PJI following TJA, but seven other studies found no correlation. Meta-analysis found that the risk of two-stage revision failure of PJI following TJA significantly boosted by 3.53 times in patients with BMI ≥ 30 kg/m2 (OR = 3.53; 95% CI = 1.63-7.64 for the BMI ≥ 30 kg/m2 vs. BMI < 30 kg/m2) and the risk of two-stage revision failure of PJI following TJA significantly increased by 2.92 times in patients with BMI ≥ 40 kg/m2 (OR = 2.92; 95%CI = 1.06-8.03 for the BMI ≥ 40 kg/m2 vs. BMI < 30 kg/m2). The subgroup analysis showed that significant association was observed among the studies performed in TKA (OR = 3.63; 95% CI = 2.27-5.82), but not among those conducted in THA (OR = 3.06; 95% CI = 0.42-22.19). A significant association remained consistent, as indicated by sensitivity analyses. Because there are too few studies that can be combined in the included studies, Egger's and Begg's tests were not performed. Conclusion: Meta-analysis suggests that the risk of two-stage revision failure of PJI following TJA significantly boosted in obese patients. However, because there may be publication bias of this study, combined overall systematically evaluated and meta-analysis results, we cannot yet conclude that BMI is associated with two-stage revision failure of PJI following TJA.

Soil Bacterial Community in the Multiple Cropping System Increased Grain Yield Within 40 Cultivation Years.

The shortage of land resources restricts the sustainable development of agricultural production. Multiple cropping has been widely used in Southern China, but whether the continuous planting will cause a decline in soil quality and crop yield is unclear. To test whether multiple cropping could increase grain yield, we investigated the farmlands with different cultivation years (10-20 years, 20-40 years, and >40 years). Results showed that tobacco-rice multiple cropping rotation significantly increased soil pH, nitrogen nutrient content, and grain yield, and it increased the richness of the bacterial community. The farmland with 20-40 years of cultivation has the highest soil organic carbon (SOC), ammonium nitrogen, and grain yield, but there is no significant difference in the diversity and structure of the bacterial community in farmlands with different cultivation years. The molecular ecological network indicated that the stability of the bacterial community decreased across the cultivation years, which may result in a decline of farmland yields in multiple cropping system> 40 years. The Acidobacteria members as the keystone taxa (Zi ≥ 2.5 or Pi ≥ 0.62) appeared in the tobacco-rice multiple cropping rotation farmlands, and the highest abundance of Acidobacteria was found in the farmland with the highest SOC and ammonium nitrogen content, suggesting Acidobacteria Gp4, GP7, GP12, and GP17 are important taxa involved in the soil carbon and nitrogen cycle. Therefore, in this study, the multiple cropping systems for 20 years will not reduce the crop production potential, but they cannot last for more than 40 years. This study provides insights for ensuring soil quality and enhancing sustainable agricultural production capacity.

Resuscitative Endovascular Balloon Occlusion of the Aorta for Blood Control in Lumbar Spine Tumor Resection Surgery: A Technical Note.

OBJECTIVES: To describe the technique of the aorta balloon occlusion, and evaluate the blood loss in lumbar spine tumor surgery assisted by aortic balloon occlusion, and to observe the balloon-related complications. METHODS: Six patients with lumbar spine tumor underwent resuscitative endovascular balloon occlusion of the aorta prior to tumor resections in our institution between May 2018 to January 2021. Medical records including demographic, diagnosis, tumor location, surgical approach, intraoperative blood loss, surgical duration, and perioperative balloon-related complication were evaluated retrospectively. RESULTS: This series included four males and two females, with a median age of 50 years (range 22 to 69). Of these, three primary tumors were plasmacytoma, giant cell tumor of bone, and osteosarcoma, while recurrence of undifferentiated pleomorphic sarcoma (UPS), recurrence of giant cell tumor of bone (GCT), and metastatic thyroid cancer were diagnosed in cases 1, 6, and 2, respectively. L2 was involved in cases 1 and 5. L3 was involved in case 6. L4 was involved in case 2, 3, and 6. L5 was involved in case 4. One-stage total en bloc resection surgery (TES) was accomplished in all patients; of this series, signal anterior approach was conducted in case 1, signal posterior approach was utilized in cases 2, 3, and 6, while combined anterior and posterior approach was performed in cases 4 and 5. The median intraoperative blood loss was 1683 mL and ranged from 400 to 3200 mL with a median surgical duration of 442 min and a range from 210 to 810 min. During the perioperative period, no serious balloon-related complications occurred. CONCLUSIONS: Endovascular balloon occlusion of the aorta successfully controls intraoperative exsanguination, contributing to a more radical tumor resection and a low rate of tumor cell contamination in lumbar tumor surgery.

Chloroquine inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis.

The present study was to investigate the anticancer effect of chloroquine on proliferation of mouse colon cancer cell line CT26 in vivo and in vitro and the possible mechanism. We found that chloroquine inhibited CT26 proliferation by concentration- and time-dependent manner. This effect was associated with apoptosis induction and decreased level of phosphorylated p42/44 mitogen-activated protein kinase and phosphorylated Akt. The in vivo study showed chloroquine-reduced tumor volume and prolonged survival time in CT26-bearing mice. These observations indicated chloroquine could inhibit CT26 proliferation by inducing apoptosis both in vitro and in vivo, providing its chemotherapeutic potential of human cancers.

Dewatering of sewage sludge via thermal hydrolysis with ammonia-treated Fenton iron sludge as skeleton material.

In this study, the alkaline hydrothermal ferric carbon (AHFC), which was prepared by hydrothermal liquefaction method using Fenton iron sludge with NH3·H2O, was used as a skeleton materials for the dewatering of sewage sludge (SS) via thermal hydrolysis. NH2 functional group presented in the AHFC and nano-sized γ-Fe2O3 was anchored on the surface of AHFC. The NH2 functional group notably promoted thermal hydrolysis of SS from the increasing of TOC and TN value. γ-Fe2O3 showed adsorption effect to the water, resulting in decline of the dewatering rate of SS in present condition. When 100% of AHFC was added, dewatering rate of SS was decreased by 19.93% (at 160 °C), 4.50% (at 180 °C) and 8.34% (at 200 °C) respectively. 3D-EEM results showed that the degree of hydrolysis was deepened when AHFC was added for the intensity of soluble microbial products decline. AHFC promoted the decomposition of protein to form heterocycle compounds in the resulting cake according to in situ FTIR results. The nano γ-Fe2O3 catalysis to cake also can be observed for the activation energy was lower than blank in the range of 40˜60%. The study demonstrated concept and the effectiveness the reuse/recycle of the Fenton iron sludge for dewatering of SS.

Cell growth inhibition, G2/M cell cycle arrest, and apoptosis induced by chloroquine in human breast cancer cell line Bcap-37.

Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells' growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G(2)/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (DeltaPsim), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (DeltaPsim), and induction of spindle abnormalities.

[Application of contralateral supplementary puncture in unilateral percutaneous vertebroplasty for poor bone cement dispersion].

OBJECTIVE: To evaluate the clinical value of contralateral supplementary puncture in unilateral percutaneous vertebroplasty(PVP) with poor cement dispersion. METHODS: From January 2015 to December 2016, PVP was performed unilaterally in 285 patients(319 vertebrae) with osteoporotic compression fractures(OVCF). Contralateral percutaneous puncture was performed in 13 patients with poor cement dispersion. Among the patients, 5 cases were male and 8 patients were female, ranging in age from 63 to 88 years old; 1 case of T11, 4 cases of T12, 3 cases of L1, 2 cases of L2, 1 case of L3, and 2 cases of L5. The time from injury to operation ranged from 1 to 16 days. The VAS score, ODI score, residual low back pain and loss of vertebral height were observed. RESULTS: The VAS score and ODI score of 13 patients who underwent contralateral supplementary puncture were significantly improved (P<0.01), and there was no postoperative residual low back pain. During the follow-up period, there was no significant difference in the height loss between the two sides of the vertebral body (0.35 to 3.69 mm on the original puncture side and 0.59 to 3.66 mm on the supplementary puncture side). CONCLUSIONS: For unilateral PVP with poor cement dispersion, contralateral puncture can reduce the occurrence of postoperative residual pain; at the same time, can reduce the difference between the loss of height on both sides of the vertebral body, and then prevent the occurrence of lateral vertebral deformity, which is a safe and reliable method.

[Progress in the design of selective ATP-competitive kinase inhibitors].

Kinases play crucial roles in the life of cell. Their functional abnormity usually leads to many human major diseases including tumors. The prospecting of ATP-competitive small-molecule kinase inhibitors targeting kinases of therapeutic interest has become the focus of researches. Due to the high conservation of the catalytic domain of kinases, the selectivity of kinase inhibitors is poor in general. However, along with the development of structural biology and computer-aided drug design, great progress in the research of selective, ATP-competitive kinase inhibitors has been achieved in recent years. In this account, the review has been made on the development of the design of selective kinase inhibitors.

Effect of pH, temperature, humic acid and coexisting anions on reduction of Cr(â ¥) in the soil leachate by nZVI/Ni bimetal material.

Nano zero valent iron/Ni bimetal materials (nZVI/Ni) were prepared by borohydride reduction method to remediate toxic Cr(Ⅵ) contaminated in soil leachate. nZVI/Ni was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Different factors including pH value of soil leachate, reaction time, temperature, humic acid and coexisting anions (SO42-, NO3-, HCO3-, CO32-) were studied to analyze the reduction rate. Results showed that the reduction rate of Cr(Ⅵ) could reach 99.84% under the condition of pH of 5 and temperature of 303 K. pH values and temperature of soil leachate had a significant effect on the reduction efficiency, while humic acid had inhibition effect for the reduction reaction. SO42-, HCO3- and CO32- had inhibition effect for reduction rate, while NO3- barely influenced the reduction process of nZVI/Ni. Moreover, Langumir-Hinshelwood first order kinetic model was studied and could describe the reduction process well. The thermodynamic studies indicated that the reaction process was endothermic and spontaneous. Activation energy was 143.80 kJ mol-1, showing that the reaction occurred easily. Therefore, the study provides an idea for nZVI/Ni further research and practical application of nZVI/Ni in soil remediation.

Antitumor and antimetastatic activities of chloroquine diphosphate in a murine model of breast cancer.

Metastatic breast cancers are hard to treat and almost always fatal. Chloroquine diphosphate, a derivative of quinine, has long been used as a potent and commonly used medicine against different human diseases. We therefore investigated the effects of chloroquine diphosphate on a highly metastatic mouse mammary carcinoma cell line. In vitro treatment of 4T1 mouse breast cancer cells with chloroquine diphosphate resulted in significant inhibition of cellular proliferation and viability, and induction of apoptosis in 4T1 cells in a time- and dose-dependent manner. Further analysis indicated that induction of apoptosis was associated with the loss of mitochondrial membrane potential, release of cytochrome c, and activation of caspase-9 and caspase-3, and cleavage of poly(ADP-ribose) polymerase. The effect of chloroquine diphosphate was then examined using a mice model in which 4T1 cells were implanted subcutaneously. Chloroquine diphosphate (25mg/kg and 50mg/kg, respectively) significantly inhibited the growth of the implanted 4T1 tumor cells and induced apoptosis in the tumor microenvironment. Moreover, the metastasis of tumor cells to the lungs was inhibited significantly and the survival of the mice enhanced. These data suggested that chloroquine diphosphate might have chemotherapeutic efficacy against breast cancer including inhibition of metastasis.

Excitotoxicity in rat's brain induced by exposure of manganese and neuroprotective effects of pinacidil and nimodipine.

Manganese (Mn) is an essential trace element for humans. However, manganism would be caused by excessive Mn. The mechanisms underlying excitotoxicity induced by manganism are poorly understood. As it is known to us, glutamate (Glu) is the most prevalent excitatory neurotransmitter. To determine the possible role of dysfunction of Glu transportation and metabolism in Mn-induced excitotoxicity, the rats were ip injected with different dose of MnCl(2) (0, 50, 100, and 200 micromol/kg), the levels of Mn and activities of GS, PAG, Na(+)-K(+)-ATPase, and Ca(2+)-ATPase in striatum were investigated. In addition, effect of 20.38 micromol/kg pinacidil (K(+) channel opener) or 2.4 micromol/kg nimodipine (Ca(2+) channel blocker) were studied at 200 micromol/kg MnCl(2). With dose-dependent inhibition of GS, Na(+)-K(+)-ATPase, and Ca(2+)-ATPase activities, increase of Mn levels and PAG activity were observed. Further investigation indicated that pre-treatment of pinacidil or nimodipine reversed toxic effect of MnCl(2) significantly. These results suggested that MnCl(2) could induce dysfunction of Glu transportation and metabolism by augmenting the excitotoxicity dose-dependently; pinacidil and nimodipine might antagonize manganese neurotoxicity.