Comparison of unilateral and bilateral puncture percutaneous kyphoplasty in the treatment of osteoporotic vertebral compression fractures.

OBJECTIVES: To compare the clinical efficacy of unilateral and bilateral puncture PKP in the treatment of OVCFs and explored whether there is a difference in the efficacy of unilateral and bilateral puncture PKP after surgery. METHODS: A total of 98 patients with OVCFs treated by PKP from August 2016 to June 2018 were selected. There were 62 cases in the unilateral puncture group and 36 cases in the bilateral puncture group. The operation time, the amount of bone cement injection, the height of the anterior edge of the vertebral body and the visual analog scale (Visual Analog Scale, VAS) scores before and after the operation were analyzed, and whether the differences between the 2 groups were statistically significant was analyzed. RESULTS: All patients were followed up completely. The operation time and the number of X-ray fluoroscopies of the unilateral puncture group were significantly reduced compared to those of the bilateral group, and the difference was statistically significant (p<0.05). In terms of the bone cement injection volume, the average injection volume of the bilateral group was greater than that of the unilateral group, and the difference was statistically significant (p<0.05); the postoperative VAS scores of the 2 groups of patients were significantly improved, and the difference was statistically significant compared with that before surgery (p<0.05) but that of the unilateral group was not statistically significant compared with that of the bilateral group (p>0.05). The height of the anterior edge of the vertebral body in both groups was significantly improved compared with that before the operation, and the difference was statistically significant (p<0.05). CONCLUSION: Unilateral and bilateral puncture PKP can achieve good clinical efficacy in the treatment of osteoporotic vertebral compression fractures, but unilateral PKP has the advantages of short operation time and low X-ray exposure.

Neuregulin-1 promotes mitochondrial biogenesis, attenuates mitochondrial dysfunction, and prevents hypoxia/reoxygenation injury in neonatal cardiomyocytes.

Neuregulin-1 (NRG-1)/erythroblastic leukaemia viral oncogene homologues (ErbB) pathway activation plays a crucial role in regulating the adaptation of the adult heart to physiological and pathological stress. In the present study, we investigate the effect of recombined human NRG-1 (rhNRG-1) on mitochondrial biogenesis, mitochondrial function, and cell survival in neonatal rat cardiac myocytes (NRCMs) exposed to hypoxia/reoxygenation (H/R). The results of this study showed that, in the H/R-exposed NRCMs, mitochondrial biogenesis was impaired, as manifested by the decrease of the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) and mitochondrial membrane proteins, the inner membrane (Tim23), mitofusin 1 (Mfn1), and mitofusin 2 (Mfn2). RhNRG-1 pretreatment effectively restored the expression of PGC-1α and these membrane proteins, upregulated the expression of the anti-apoptosis proteins Bcl-2 and Bcl-xL, preserved the mitochondrial membrane potential, and attenuated H/R-induced cell apoptosis. Blocking PGC-1 expression with siRNA abolished the beneficial role of rhNRG-1 on mitochondrial function and cell survival. The results of the present study strongly suggest that NRG-1/ErbB activation enhances the adaption of cardiomyocytes to H/R injury via promoted mitochondrial biogenesis and improved mitochondrial homeostasis. SIGNIFICANCE OF THE STUDY: The results of this research revealed for the first time the relationship between neuregulin-1 (NRG-1)/erythroblastic leukaemia viral oncogene homologues (ErbB) activation and mitochondrial biogenesis in neonatal cardiomyocytes and verified the significance of this promoted mitochondrial biogenesis in attenuating hypoxia/reoxygenation injury. This finding may open a new field to further understand the biological role of NRG-1/ErbB signalling pathway in cardiomyocyte.

Relationship between inflammation and progression of an abdominal aortic aneurysm in a rabbit model based on 18F-FDG PET/CT imaging.

OBJECTIVE: To explore the relationship between abdominal aortic aneurysm development and inflammation in the rabbit through the establishment of a rabbit infrarenal abdominal aortic aneurysm model and the use of 18F-FDG PET/CT imaging. METHODS: Twenty male New Zealand rabbits were administered an elastase intracavity perfusion to induce an infrarenal abdominal aortic aneurysm model. Prior to surgery, the rabbits underwent abdominal aorta ultrasonic testing and blood collection from the ear veins. Of the original 20 rabbits, 10 rabbits were euthanized two weeks after the operation following ultrasonic testing, PET/CT scanning and blood collection, and their arterial tissue samples were prepared for pathological and immunohistochemical staining. The remaining 10 rabbits were euthanized four weeks after the operation following ultrasonic testing, PET/CT scanning and blood collection, and the arterial tissue samples were prepared for pathological and immunohistochemical staining. RESULTS: Compared with the preoperative measurement, the maximum growth rate of the aneurysm diameter is 89.21 ± 0.02% (the absolute increase in diameter is 2.040 ± 0.376 mm) two weeks after the operation. Compared with the two-week postoperative value, the maximum growth rate of the aneurysm diameter is 15.8 ± 0.01% (the absolute increase in diameter is 0.684 ± 0.115 mm) four weeks after the operation. Compared with the preoperative values, the blood MMP-2 and MMP-9 levels significantly increase two weeks after surgery, P < 0.05. Compared with the two-week postoperative values, the blood MMP-2 and MMP-9 levels significantly decrease after four weeks post-surgery, P < 0.05. At two weeks after the operation, the SUVmax and the TBR of the 18F-FDG PET/CT of the AAA wall are 0.90 ± 0.03 and 1.19 ± 0.09, respectively. At four weeks after the operation, the SUVmax and the TBR of the 18F-FDG PET/CT of the AAA wall are 0.35 ± 0.05 and 1.15 ± 0.12, respectively. Compared with two weeks after the operation, the SUVmax significantly decreases at four weeks after the operation, P < 0.05. Compared with two weeks after the operation, there is no significant difference in the TBR at four weeks after the operation, P > 0.05. Immunohistochemical staining shows that the CD68-positive cell rate at four weeks after the operation significantly decreases ( P < 0.05) compared with the CD68-positive cell rate at two weeks after the operation. CONCLUSION: In the early stages of abdominal aortic aneurysm development, the inflammatory response of the arterial wall is significant, the local metabolic activity is strengthened, the SUVmax value of 18F-FDG is high, and the abdominal aortic aneurysm diameter experiences rapid growth. In the later stages of abdominal aortic aneurysm development, the diameter continues to increase; however, there are decreases in the wall inflammatory response, the local metabolic activity, and the SUVmax value of 18F-FDG. Thus, inflammation plays an important role in the early development of abdominal aortic aneurysm.

[Effects of thyroid hormone on macrophage dysfunction induced by oxidized low-density lipoprotein].

It has been recognized that patients with hypothyroidism have higher risks of atherosclerosis and coronary heart disease, however, the mechanisms are largely unknown. Considering that macrophage dysfunction plays an important role in the formation and development of atherosclerosis plaques, this study aimed to investigate the direct effects of thyroid hormone on macrophage functions and to provide new insight for the mechanism of hypothyroid atherosclerosis. RAW264.7 cells (mouse leukaemic monocyte macrophage cell line) were incubated with oxidized low-density lipoprotein (oxLDL) to establish macrophage foam cells model in vitro, and the protective effects of different concentration of thyroxine (T4) on the macrophage foam cells function were explored. The proliferation, migration and cell aging of macrophages were detected by MTT method, scratch test and ß-galactosidase staining respectively. The ELISA method was used to detect the secretion of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-1ß (IL-1ß). Western blot analysis was applied to measure the phosphorylation of focal adhesion kinase (FAK), which was required for the process of proliferation and migration of macrophages. The results showed that oxLDL significantly inhibited the macrophage proliferation and migration, induced cell senescence, and promoted the secretion of TNF-α, MCP-1, and IL-1ß; while T4 reversed those effects of oxLDL on macrophage in a concentration-dependent manner. Moreover, oxLDL increased the phosphorylation of FAK in macrophage, while T4 concentration-dependently reversed the effect. These results suggest that T4 modulates macrophage proliferation, migration, senescence, and secretion of inflammation factors in a concentration-dependent way.

Diagnostic Value of Serum Procalcitonin in Early Infection after Internal Fixation for Traumatic Fracture.

BACKGROUND: This study aimed to observe the changes of serum procalcitonin (PCT) and C-reactive protein (CRP) concentrations after internal fixation for traumatic fracture and to discuss the diagnostic value of these two indicators in early infection after internal fixation for traumatic fracture. METHODS: Patients who received internal fixation for traumatic fracture at our hospital from June 2014 to December 2016 were included. They were divided into infection group (12 cases) and non-infection group (166 cases), depending on whether infection occurred. Venous blood samples were collected from cases in both groups on day 1, day 4, and day 9 after surgery. Changes in PCT and CRP levels were detected at different time points. RESULTS: As compared with the non-infection group, PCT and CRP levels were significantly increased at each time point after surgery in the infection group. The sensitivity of PCT combined with CRP in the detection of early infection after surgery was higher than that of either used alone. CONCLUSIONS: The serum PCT level can be used as an early diagnostic indicator of infection after internal fixation for traumatic fracture. The combined use of PCR and CRP levels can increase the sensitivity of detection.

The Value of Radionuclide Bone Imaging in Defining Fresh Fractures Among Osteoporotic Vertebral Compression Fractures.

Vertebral fractures are the most common osteoporotic fractures. To perform percutaneous vertebral body cement augmentation, it is essential to accurately identify the affected vertebrae. The study evaluated the role of radionuclide bone imaging in identifying fresh osteoporotic vertebral compression fractures. A prospective study of 39 patients with acute osteoporotic vertebral compression fractures was carried out. All patients underwent magnetic resonance imaging (MRI) and radionuclide bone imaging to determine if the fractures were fresh, followed by percutaneous kyphoplasty for the fresh fractures. The positive rate on radionuclide bone imaging was 92.1% (82/89), and the positive rate on MRI was 93.3% (83/89), with no statistically significant difference (P > 0.05). Eighty-one vertebrae had the same positive identification by both radionuclide bone imaging and MRI, and 5 of the same vertebrae were diagnosed negative by both techniques. One patient with positive radionuclide bone imaging was negative according to MRI, and 2 patients were entirely positive by MRI but negative by radionuclide bone imaging. A kappa test showed good consistency between the 2 methods for detecting the affected vertebrae (Kappa = 0.751, P < 0.01). Radionuclide bone imaging is as sensitive as MRI in the diagnosis of fresh osteoporotic vertebral compression fracture, making it an effective method for detecting affected vertebrae for percutaneous vertebroplasty.

Treatment of comminuted patellar fracture with the nitinol patellar concentrator.

AIM: To evaluate the clinical effect of the nitinol (NiTi)-patellar concentrator (NT-PC) for the treatment of comminuted patellar fractures. MATERIAL AND METHODS: A total of 32 patients with acute comminuted patellar fracture accepted open reduction and internal fixation with the NT-PC, and the curative effects were evaluated using the Böstman clinical grading scale. RESULTS: All fractures were anatomically reduced by surgery and all cases were followed-up for six to 18 months. The mean score of patients according to the Böstman clinical grading scale was 25.6, with 29 of 32 (90.7%) patients achieving excellent or good results. Two patients had traumatic arthritis, one had slippage of the NT-PC, and all patients received pharmacotherapy. CONCLUSIONS: The application of the NT-PC is a satisfactory approach to the treatment of comminuted patellar fractures.

Fabrication of hydroxyapatite on pure titanium by micro-arc oxidation coupled with microwave-hydrothermal treatment.

Porous hydroxyapatite (HA)-containing composite films were prepared by a novel method consisting of micro-arc oxidation (MAO) combined with microwave-hydrothermal (M-H) treatment. The morphology, composition and phase composition of the bioactive films were investigated with scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction. MTT assay was carried out to investigate the in vitro effects of the different surfaces on bone integration properties. The prepared MAO films consisted mainly of anatase, rutile and tricalcium phosphate along with amorphous calcium (Ca) and phosphorus (P) phases. The M-H-treated composite films were composed primarily of anatase, rutile and HA. As the time and temperature of the M-H treatment increased, the number of HA crystals gradually increased. Using the M-H method, HA was obtained at a lower temperature and in a shorter period of time compared to the conventional hydrothermal method. The results suggest that the M-H method significantly decreases the hydrothermal reaction temperature and also greatly shortens the reaction time. Due to the nanocrystallinity and porosity of the prepared composite films, the method presented here shows promise for the formation of bioactive materials for medical applications.

[Noninvasive imaging of vulnerable plaques and thromboses with PET/CT complex imaging technique].

OBJECTIVE: To investigate the feasibility of identifying the vulnerable plaque and predicting plague rupture and thrombus using by positron emission tomography/computed tomography angiography (PET/CTA). METHODS: Twenty-eight male New Zealand white rabbits were fed with hyper-lipid diet for 2 weeks before the balloon injury of the abdominal aorta.Then these rabbit were intermittently fed with hyper-lipid diet for 14 weeks, in order to trigger pharmaceutic the plague rupture and thrombus. PET/CTA scans of abdominal aorta were performed before and after the drug triggering, FDG uptake (standardized uptake value, SUV) was measured. Rabbits were euthanized to obtain data of pathology and histology. The parameters obtained by PET/CTA, pathology and histology were compared and the correlations were performed. RESULTS: The thrombosis was identified in 13 of 20 rabbits.Before the drug triggering, (18)F-FDG mean standardized uptake value (SUVmean) was higher in thrombotic arterial segments (defined as vulnerable plaque) (1.10 ± 0.19 vs 0.77 ± 0.11,P = 0.000); after the drug triggering, SUVmean was higher in thrombotic arterial segments, too (1.15 ± 0.26 vs 0.85 ± 0.17, P = 0.000). We use the ROC curve for SUVmean to predict plaque rupture and thrombosis. The area under the curve (AUC) was 0.898 (P = 0.000). The cutoff value was 0.882. CONCLUSIONS: Our findings indicated that (18)F-FDG PET/CTA, as a noninvasive imaging method, could be used to identify vulnerable plaques and predict thrombosis events.

Expression and localization of receptor tyrosine kinase Tyro3 in rat brain.

OBJECTIVE: To detect the expression patterns and localization of the Tyro3, Axl, and Mer (TAM) receptor tyrosine kinases in the rat brain, and to understand the significance of this receptor family in the brain. METHODS: Sprague Dawley rats aged P3 (day 3 of postnatal development), P9, P15, P30 and P52 were anesthetized and their brains removed. Real time quantitative PCR was used to determine mRNA expression levels of TAM. Western blotting was applied to analyze protein expression levels of TAM peptides. The immunohistochemical stainings of Tyro3 protein in adult rat brains were detected by the avidin-biotin-peroxidase complex method. RESULTS: Tyro3 was the most highly expressed and widely distributed receptor among TAM family. Its mRNA level increased dramatically during the second postnatal week, reached at the highest level by P30, and remained at that level in the adult. The relative expression quantitative of Tyro3 mRNA in the adult rat brain increased about 3.2-fold than that at P15 stage. The expression of Tyro3 protein was detected faintly at early stage, gradually increased from P15, and reached maximal levels at adult stage. The relative density of immunoreactive product of Tyro3 peptide in the rat brain was up-regulated 1.3-fold from P15 to adult (P52). Immunohistochemical stainings demonstrated that Tyro3 protein was detected in the majority of cells of all the cortical layers. Strong signals were observed in the piriform cortex and the hippocampus. At the subcellular level, Tyro3 was detected both in the soma and dendrites of pyramidal neurons. CONCLUSION: The results imply that Tyro3 is the main TAM receptor tyrosine kinase expressed in adult rat brain that modulates signaling cascades influencing synaptic function in the brain.

[Impact of anemia on long-term outcome in elderly patients with acute coronary syndrome undergoing percutaneous coronary interventions].

OBJECTIVE: To assess the impact of pre-procedure anemia on the long-term mortality in elderly patients with acute coronary syndrome (ACS) after percutaneous coronary interventions. METHODS: A total of 1014 ACS patients (≥ 60 years of age) with hemoglobin data and without previous treatment with thrombolytic agents and without end-stage renal failure before the interventional procedure were included. Patients were classified as anemia using the definition of World Health Organization: hemoglobin < 130 g/L in men, and < 120 g/L in women. A total of 253 patients were anemia. The clinical features of patients with and without anemia and association of pre-procedure anemia with long-term mortality were analyzed. RESULTS: Incidence of diabetes and serum creatinine level were significantly higher in anemia patients than in non-anemia patients while systolic blood pressure and low-density lipoprotein cholesterol were significantly lower in anemia patients than in non-anemia patients (P < 0.05 or P < 0.01). The patients were followed up for 528 (178 - 675) days. After adjustment for potential co-variants in Cox regression analysis, pre-procedure anemia was associated with a significantly higher long-term mortality (RR: 3.293, 95%CI: 1.431 - 7.578, P < 0.01). CONCLUSION: Pre-procedure anemia is an independent predictor of long-term mortality in elderly patients with acute coronary syndrome after percutaneous coronary interventions.

Electrochemical-enhanced MoS2/Fe3O4 peroxymonosulfate (E/ MoS2/Fe3O4/PMS) for degradation of sulfamerazine.

Seeking effective methods to degrade organic pollutants has always been a hot research field. In this work, MoS2/Fe3O4 catalyst was synthesized by hydrothermal method with MoS2 as carrier to construct an advanced oxidation system of electrochemical enhanced MoS2/Fe3O4-activated peroxymonosulfate (E/MoS2/Fe3O4/PMS). The materials were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The degradation efficiency of sulfamerazine (SM1) by E/MoS2/Fe3O4/PMS system was investigated and reaction mechanism was explored. The results showed that the removal rates of SM1 within 30 min were 31%, 20% and 89% with Fe3O4, MoS2 and MoS2/Fe3O4 as catalysts, respectively. The characterization results revealed that Fe(III) on the surface of Fe3O4 was reduced to Fe(II) and Mo(IV) was oxidized to Mo(VI) in the presence of MoS2. The synergistic effect between Fe3O4 and MoS2 enhanced the PMS decomposition and improved the SM1 removal efficiency. Free radical quenching experiments showed that SO4-⋅, ·OH, O2· and 1O2 were all involved in the degradation of SM1, and the effect of 1O2 was more significant than other active substances. Low concentrations of Cl- and humic acid (HA) had no significant inhibitory effect on the degradation of SM1, while HCO3- had a significant inhibitory effect on the E/MoS2/Fe3O4/PMS system. In addition, catalyst cycling experiments showed that MoS2/Fe3O4 maintained good stability before and after the catalytic reaction process.

Osteoblast Response to Copper-Doped Microporous Coatings on Titanium for Improved Bone Integration.

Due to their excellent mechanical properties and good biocompatibility, titanium alloys have become a popular research topic in the field of medical metal implants. However, the surface of the titanium alloy does not exhibit biological activity, which may cause poor integration between the interface of the titanium implant and the interface of the bone tissue and subsequently may cause the implant to fall off. Therefore, surface biological inertness is one of the problems that titanium alloys must overcome to become an ideal orthopedic implant material. Surface modification can improve the biological properties of titanium, thereby enhancing its osseointegration effect. Copper is an essential trace element for the human body, can promote bone formation and plays an important role in maintaining the physiological structure and function of bone and bone growth and development. In this study, a microporous copper-titanium dioxide coating was prepared on the surface of titanium by microarc oxidation. Based on the evaluation of its surface characteristics, the adhesion, proliferation and differentiation of MC3T3-E1 cells were observed. A titanium rod was implanted into the rabbit femoral condyle, and the integration of the coating and bone tissue was evaluated. Our research results show that the microporous copper-titanium dioxide coating has a nearly three-dimensional porous structure, and copper is incorporated into the coating without changing the structure of the coating. In vitro experiments found that the coating can promote the adhesion, proliferation and differentiation of MC3T3-E1 cells. In vivo experiments further confirmed that the titanium copper-titanium dioxide microporous coating can promote the osseointegration of titanium implants. In conclusion, copper-titanium dioxide microporous coatings can be prepared by microarc oxidation, which can improve the biological activity and biocompatibility of titanium, promote new bone formation and demonstrate good osteoinductive properties. Therefore, the use of this coating in orthopedics has potential clinical application.

Cu-Co Co-Doped Microporous Coating on Titanium with Osteogenic and Antibacterial Properties.

Titanium (Ti) and its alloys are widely used in bone surgery by virtue of their excellent mechanical properties and good biocompatibility; however, complications such as loosening and sinking have been reported post-implantation. Herein we deposited a copper-cobalt (Cu-Co) co-doped titanium dioxide (TUO) coating on the surface of Ti implants by microarc oxidation. The osteogenic and antimicrobial properties of the coating were evaluated by in vitro experiments, and we also assessed ß-catenin expression levels on different sample surfaces. Our results revealed that the coating promoted the adhesion, proliferation, and differentiation of MG63 osteoblasts, and TUO coating promoted ß-catenin expression; moreover, the proliferation of Staphylococcus aureus was inhibited. To summarize, we report that Cu-Co co-doping can enhance the osteogenic and antibacterial activities of orthopedic Ti implants, leading to potentially improved clinical performance.

A study on the risk factors of coronary artery disease in patients with Takayasu arteritis.

BACKGROUND: The aim of this study was to investigate the risk factors of Takayasu arteritis (TA) involving the coronary artery. METHODS: Patients with TA involving coronary artery were included in this study. According to the patients' condition of coronary artery involvement, they were divided into two groups: group A: TA involved coronary artery disease [at least one coronary artery stenosis (≥50%)] and group B: TA did not involve coronary artery. A logistic regression model was used to analyze the risk factors of arteritis involving the patients' coronary artery lesions. RESULTS: A total of 442 TA patients were included in this study. The patients were significantly older in group A than those patients in group B (52.54±11.17 vs. 37.73±12.72, P<0.001). The age of onset in group A was significantly older than those patients in group B (42.21±11.46 vs. 32.74±13.13, P<0.001). The patients in group A had a longer course of disease (P<0.001), larger BMI (P=0.002) and higher rates of smoking, drinking, diabetes, dyslipidemia (P<0.05) when compared with group B. The level of eGFR was significantly decreased and the UA and TG levels were significantly increased in group A when compared with group B(P<0.05). Besides, the risk factors for TA involving coronary artery included the age of TA onset (OR =1.143, 95% CI: 1.007-1.298, P=0.039), course of TA (OR =1.165, 95% CI: 1.025-1.324, P=0.020), and BMI (OR =1.100, 95% CI: 1.021-1.185, P=0.013). CONCLUSIONS: The later the age of TA onset, the longer the course of TA onset and the more traditional risk factors associated with atherosclerosis, the more vulnerable patients are to coronary artery involvement and this may not be related to clinical disease activity.

Enhanced osteogenic activity and antibacterial ability of manganese-titanium dioxide microporous coating on titanium surfaces.

Titanium (Ti) and its alloys are widely used in clinical practice as preferred materials for bone tissue repair and replacement because of their good mechanical properties; however, as Ti lacks biological activity, clinical application has been limited. Herein, we prepared a manganese-titanium dioxide (Mn-TiO2) microporous biotic coating on Ti surfaces by micro-arc oxidation (MAO). The coating showed good surface topography and was uniformly doped with Mn, and the Mn ions were slowly released. In vitro, the Mn-TiO2 microporous biotic coating promoted the adhesion, proliferation, differentiation, and mineralization of MC3T3-E1 osteoblasts. Moreover, in vivo experiments showed that the coating promoted early osseointegration. We also conducted a preliminary investigation to explore the molecular mechanism underlying the regulation of the function of osteoblasts by the coating. Furthermore, we found that the coating could inhibit the growth of Escherichia coli in vitro, demonstrating reliable antibacterial ability. To conclude, Mn-TiO2 microporous biotic coating can improve the biological activity of Ti implants, which can potentially improve their clinical applications.

Osteogenic activity of a titanium surface modified with silicon-doped titanium dioxide.

Titanium and its alloys are the most widely used implants in clinical practice. However, their bioactivity is unsatisfactory, and the effect of osteogenesis on the bonding interface between the implant and bone needs to be further improved. In this study, a coating consisting of microporous titanium doped with silicon (Si-TiO2) was successfully created by microarc oxidation (MAO), and Si was evenly distributed on the surface of the coating. The surface morphology, roughness, and phase composition of the Si-TiO2 microporous coating were similar to those of the Si-free doped MAO coatings. The Si-TiO2 microporous coating can promote osteoblast adhesion, spreading, proliferation and differentiation. More importantly, the integrin ß1-FAK signaling pathway may be involved in the regulatory effect of the coating on osteoblasts. Further studies in vivo indicated that the Si-TiO2 microporous coating could improve early stage osseointegration. In conclusion, the Si-TiO2 microporous coating is a feasible way to improve the osteogenic abilities of Ti implants to potentially promote clinical performance.

Long-Term Effects of the Abdominal Aortic Aneurysm Model in Rabbits Prepared by Pancreatic Elastase Combined With Angiotensin II.

OBJECTIVE:: This study aimed to observe the effect of pancreatic elastase combined with angiotensin II on a stable rabbit abdominal aortic aneurysm model. METHODS:: A total of 20 male New Zealand rabbits were randomly divided into groups A and B, with 10 rabbits per group. The rabbits in group A were given an intraperitoneal perfusion of pancreatic elastase, and the rabbits in group B were given continuous pumping of angiotensin II in addition to the operation of group A. Before the operation and at 2, 4, and 16 weeks postoperation, vascular color Doppler ultrasonography was performed, and blood samples were collected to measure the serum matrix metalloproteinase 9 (MMP9) and MMP2 levels. At 16 weeks postoperation, all rabbits in both groups were killed, and hematoxylin and eosin, Elastic-van-Gieson, Masson's, and immunohistochemical staining were performed for the vessel specimens. RESULTS:: At 2 weeks postoperation, the aneurysm formation rates of the 2 groups were both 100%, and the average expansion rates of the aneurysm diameters were 85% and 93%, respectively; these differences were not significant ( P = .150 and P = .280, respectively). At 4 weeks postoperation, the aneurysm formation rates of the 2 groups were 71.4% and 100%, and the average expansion rates of the aneurysm diameter were 68% and 99%, respectively; the differences between the groups were significant ( P = .031 and P = .022, respectively). At 16 weeks postoperation, the aneurysm formation rates of the 2 groups were 14.3% and 100%, and the average expansion rates of the aneurysm diameter were 12% and 108%, respectively; the differences between the groups were significant ( P = .026 and P = .014, respectively). CONCLUSION:: Compared to the abdominal aortic aneurysm modeling method in rabbits based on pancreatic elastase alone, the abdominal aortic aneurysm modeling method in rabbits using pancreatic elastase combined with angiotensin II maintained the morphology of the abdominal aortic aneurysm for a longer time, showing an important application value for the long-term observation of changes in abdominal aortic aneurysms.

[In vivo noninvasive detection of vulnerable atherosclerotic plaque by (99)Tc(m)-Annexin V imaging in an atherosclerotic rabbit model.].

OBJECTIVE: Apoptosis contributes to the instability of the atherosclerotic (AS) lesions. The vulnerable plaque was identified in vivo by detecting the apoptosis with radiolabeled annexin V in an atherosclerotic rabbit model. METHODS: Eight male New Zealand white rabbits on 2% cholesterol diet for 2 weeks had abdominal aortic balloon injury and fed a 2% cholesterol diet for another 15 weeks (AS group), 3 rabbits fed a normal rabbit chow for 17 weeks without balloon injury served as controls. Annexin V labeled with (99)Tc(m) was then intravenously administered and planar whole-body images were captured using a gamma camera in the left lateral position. The entire length of the abdominal aorta was explanted for ex vivo imaging with gamma camera. The aorta then was divided into several segments according to the severity of AS. The segments were separated weighted and counted in an gamma counter for the absorptive dose of annexin per gram of tissue. Histology examinations were made on specimens. RESULTS: At 2 hours post annexin V injection, clear delineation of radiolabel within the abdominal aorta could be evidenced in vivo gamma imaging. After explanation of the aorta, ex vivo imaging showed a robust uptake of radiotracer in the infradiaphragmatic aorta corresponding to the in vivo images and conforming to the macroscopic distribution of atherosclerotic lesions. The uptake of radiolabel was absent in areas without grossly visible atherosclerotic lesions. The in vivo and ex vivo images identified plaque areas were identical and corresponded histological results on the explanted specimen. The aortic specimen was divided into 18 segments on lesions. The magority of the lesions (14/18) manifested as type IV or type V lesions of AHA classification (vulnerable lesions), except segments 1 - 4, which manifested as type I or type II lesions. The thickness of fibrous cap (TFC) and the ratio of cap and lipid nuclear (RCN) were significantly reversely correlated to the unit radioactivity counts, and the correlation between RCN and the unit radioactivity counts was more significant than that between TFC and the unit radioactivity counts (r = -0.904, P < 0.01, and r = -0.8, P < 0.01). Apoptosis detection (TUNEL): annexin V intake in plaques was positively correlated to apoptotic index(r = 0.651, P = 0.012). CONCLUSION: Noninvasive Annexin V imaging could be used to detect vulnerable atherosclerotic plaques in vivo.