A finite element analysis of relationship between fracture, implant and tibial tunnel.

The purpose of this article was to use finite element analysis (FEA) to study the relationship of tibial tunnel (TT) with fracture pattern and implants. A computed tomography scan of full-length tibia and fibula was obtained. Models were built after three-dimensional reconstruction. The corresponding plates and screws were constructed and assembled together with fracture models. FEA was performed and contourplots were output. The Von Mises stresses of nodes and displacements of elements were extracted. Student's t test was used to compare the values of Von Mises stresses and displacements between corresponding models. Differences in Von Mises stresses and displacements of fragments and implants between models with and without TT were nearly all statistically significant. However, the displacements of fragments and implants for all models were < 2 mm. TT in fracture models had larger Von Mises stresses than TT in intact tibial model. However, displacements of TT in fracture models showed similar or even smaller results to those in intact tibial model. Although almost all the tested parameters were statistically significant, differences were small and values were all below the clinical threshold. This study could promote open reduction and internal fixation with one-stage reconstruction for treatment of tibial plateau fractures associated with anterior cruciate ligament (ACL) ruptures.

Evaluation of regional myocardial perfusion in methamphetamine abusers using real-time myocardial contrast echocardiography.

AIMS: To evaluate the feasibility of assessing regional myocardial perfusion using real-time myocardial contrast echocardiography (MCE) at rest for detecting coronary microcirculation abnormalities in methamphetamine abusers.Material and methods: Twenty-two male methamphetamine abusers (11 without chest pain, 11 with chest pain), free of ascertained coronary artery disease, were enrolled in this study. A control group of 22 age-matched male healthy participants was studied for comparison. Standard 2D, flow and tissue Doppler echo with measurements of cardiac morphologic and functional indicators,MCE with measurements of regional myocardial perfusion were performed, respectively. RESULTS: Compared to healthy participants, methamphetamine abusers had higher blood pressure, greater left ventricular mass index and more impaired diastolic function, with preserved cardiac sizes and systolic function. Methamphetamine abusers with chest pain had a faster heart rate than those without chest pain and healthy participants. MCE in methamphetamine abusers, especially with chest pain, had significant longer contrast agent arrival times, less functional capillary blood volumes, slower microvascular flow velocities and less myocardial perfusion than healthy participants (p<0.05). Moreover, along with the increases of dosage and duration of use (from group A to group C, group A: 1-2 g/day, <2 years; group B: 2-3 g/day, 2-5 years; group C: >3 g/day, >5 years) the reductions in the myocardial perfusion indices were more significant (p<0.01). The cutoff value with 5.1 dB2/s of the myocardial perfusion at the left ventricular apex had a sensitivity of 87.5%, specificity of 75.2% and accuracy of 81.9% for differentiating methamphetamine abusers from normal subjects. CONCLUSIONS: Real-time MCE can effectively detect coronary microcirculation abnormalities in methamphetamine abusers at rest and myocardial perfusion is significantly reduced in methamphetamine abusers. This finding may be involved in the occurrence and development of cardiac damage.

Coronary sinus flow is reduced in methamphetamine abusers: a transthoracic echocardiographic study.

To compare the coronary sinus flow among healthy participants, methamphetamine abusers without chest pain and those with chest pain. One hundred and eight methamphetamine abusers: 53 ones without chest pain, 55 ones with chest pain, free of ascertained coronary artery disease, were enrolled in this study. A control group of 50 age-matched male healthy participants was studied for comparison. Standard 2D, flow and tissue Doppler echo with measurements of cardiac morphologic and functional indicators, coronary sinus flow, and inferior vena cava (IVC) ultrasound with measurements of the IVC dimensions and their collapsibility index were performed, respectively. Compared to healthy participants, methamphetamine abusers had higher blood pressure, greater left ventricular mass index and more impaired diastolic function, with preserved cardiac sizes, systolic function and right atrial pressure. Methamphetamine abusers with chest pain had faster heart rate than those without chest pain and healthy participants. Coronary sinus flow was significantly less in methamphetamine abusers than in healthy participants (P < 0.05), and was extremely lower in those with chest pain than in healthy participants (about one-fourth) (P < 0.01). The area under the curve (AUC) of coronary sinus flow was 0.913 (0.864-0.962), and the cutoff value with 221.65 mL/min had sensitivity of 83.4%, specificity of 87.2% and accuracy of 85.2% for differentiating methamphetamine abusers from healthy participants. While the AUC of coronary sinus flow was 0.996 (0.989-1.003), and the cutoff value with 172.59 mL/min had sensitivity of 100%, specificity of 93.3% and accuracy of 96.5% for predicting methamphetamine abusers with chest pain. Coronary sinus flow is significant reduced in methamphetamine abusers, which is maybe a good indicator for indentifying methamphetamine abusers from normal population, and for predicting methamphetamine abusers with chest pain.

Findings on 3D speckle tracking echocardiography in asymptomatic methamphetamine abusers.

To detect potential cardiac abnormalities in asymptomatic methamphetamine abusers using three-dimensional speckle tracking echocardiography (3D STE). Fifty-three male methamphetamine abusers, free of cardiac symptoms/signs, were enrolled in this study. A control group of 53 age-matched male normal subjects was studied for comparison. Standard 3D, flow and tissue Doppler echo with measurements of left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF), the ratio of the early to late diastolic transmitral filling velocity (E/A), the ratio of the early diastolic transmitral filling velocity to the early diastolic septal tissue velocity (E/E') and 3D STE with measurements of global area strain (GAS), global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were performed, respectively. These echocardiographic parameters were compared between methamphetamine abusers and normal subjects, and receiver operating characteristic curve (ROC) analysis was done to differentiating methamphetamine abusers from normal subjects. LVESV, LVEDV, LVEF, E/A, E/E' ratios and GRS were not significantly different between methamphetamine abusers and normal subjects (p > 0.05). However, GAS, GLS and GCS were significantly less in methamphetamine abusers than in normal subjects (p < 0.05). The areas under ROC (AUC) for GAS were greatest among all the 3D STE derived LV global strains (GAS vs. GLS, GCS and GRS, 0.95 vs. 0.76, 0.69 and 0.61, respectively). The cutoff value with - 30.3% of GAS had sensitivity of 91.8%, specificity of 91.6% and accuracy of 91.3% for differentiating methamphetamine abusers from normal subjects. The potential myocardial function abnormalities can be detected by 3D STE in asymptomatic methamphetamine abusers, and GAS is a good indicator for indentifying methamphetamine abusers from normal population, which can be used to screening and monitor methamphetamine abuse, detect subclinical LV dysfunction, predict potential methamphetamine-related cardiotoxicity, and to initiate early cardioprotective therapy before the onset of overt heart failure in time.

Open reduction and internal fixation in a one-stage anterior cruciate ligament reconstruction surgery for the treatment of tibial plateau fractures: A case report and literature review.

Treatment of tibial plateau fractures associated with anterior cruciate ligament (ACL) injuries can be challenging. Maintaining the joint surface and axis are two main principles for the management of patients with tibial plateau fractures. Herein, we describe a patient with tibial plateau fracture of Schatzker type VI associated with complete ACL rupture. Although in a two-stage reconstruction surgery for treatment of its rupture seem to be accepted by most orthopaedic surgeons in cases of ACL injuries, we treated our patient with ORIF in a one-stage ACL reconstruction surgery. At the 1-year follow-up, the patient gained full range of motion and was functioning well. We reviewed the literature on performing ORIF in a one-stage ACL reconstruction for the treatment of tibial plateau fractures, which seemed to be a reasonable management approach that supported its use for the treatment of this patient.

Store-operated calcium entry-activated autophagy protects EPC proliferation via the CAMKK2-MTOR pathway in ox-LDL exposure.

Improving biological functions of endothelial progenitor cells (EPCs) is beneficial to maintaining endothelium homeostasis and promoting vascular re-endothelialization. Because macroautophagy/autophagy has been documented as a double-edged sword in cell functions, its effects on EPCs remain to be elucidated. This study was designed to explore the role and molecular mechanisms of store-operated calcium entry (SOCE)-activated autophagy in proliferation of EPCs under hypercholesterolemia. We employed oxidized low-density lipoprotein (ox-LDL) to mimic hypercholesterolemia in bone marrow-derived EPCs from rat. Ox-LDL dose-dependently activated autophagy flux, while inhibiting EPC proliferation. Importantly, inhibition of autophagy either by silencing Atg7 or by 3-methyladenine treatment, further aggravated proliferative inhibition by ox-LDL, suggesting the protective effects of autophagy against ox-LDL. Interestingly, ox-LDL increased STIM1 expression and intracellular Ca2+ concentration. Either Ca2+ chelators or deficiency in STIM1 attenuated ox-LDL-induced autophagy activation, confirming the involvement of SOCE in the process. Furthermore, CAMKK2 (calcium/calmodulin-dependent protein kinase kinase 2, ß) activation and MTOR (mechanistic target of rapamycin [serine/threonine kinase]) deactivation were associated with autophagy modulation. Together, our results reveal a novel signaling pathway of SOCE-CAMKK2 in the regulation of autophagy and offer new insights into the important roles of autophagy in maintaining proliferation and promoting the survival capability of EPCs. This may be beneficial to improving EPC transplantation efficacy and enhancing vascular re-endothelialization in patients with hypercholesterolemia.

Reduction of Store-Operated Ca(2+) Entry Correlates with Endothelial Progenitor Cell Dysfunction in Atherosclerotic Mice.

The dysfunction of endothelial progenitor cells (EPCs) has been shown to prevent endothelial repair during the development of atherosclerosis (AS). Previous studies have revealed that store-operated calcium entry (SOCE) is an important factor in regulating EPC functions. However, whether this is also the mechanism in AS has not been elucidated. Therefore, we evaluated the role of SOCE in EPCs isolated from an atherosclerotic mouse model. Atheromatous plaques were more frequent in the aortas of ApoE(-/-) mice fed a high-fat diet for 16 weeks compared with controls, and the proliferative and migratory activities of atherosclerotic EPCs were significantly decreased. Accordingly, SOCE amplitude, as well as spontaneous or VEGF-induced Ca(2+) oscillations, decreased in atherosclerotic EPCs. These results may be associated with the downregulated expression of Stim1, Orai1, and TRPC1, which are major mediators of SOCE. In addition, eNOS expression and phosphorylation at Ser(1177), which are critical regulators of EPC function, were markedly reduced in the atherosclerotic EPCs. The impairment of eNOS activity could also be induced by using an SOCE inhibitor or by Stim1 gene silencing, indicating a link between the activities of eNOS and SOCE in AS. Furthermore, decreased SOCE function inhibited EPC proliferation and migration in vitro. In conclusion, our results showed that the reduction of SOCE induced EPC dysfunction during AS, potentially through downregulation of store-operated calcium channel (SOCC) components and impaired eNOS activity. Approaches aimed at reestablishing SOCE activity may thus improve the function of EPCs during AS.

[The expression of Galectin-3 and VEGF in laryngeal squamous cell carcinoma].

OBJECTIVE: To investigate the expression of galectin-3 and VEGF in laryngeal squamous cell carcinoma (LSCC) tissue and to analyze its role in differentiation, growth and metastasis of the tumor. METHOD: The expression of galectin-3 and VEGF were detected with SP immunohistochemistry staining and western blot in twenty-nine specimens of LSCC and eighteen specimens of laryngeal benign lesion. RESULT: The expression of galectin-3 (89.7%) and VEGF (86.2%) in LSCC were remarkably higher than that in normal control tissue (P<0.05), and the expression of galectin-3 (89.7%) and VEGF (86.2%) in higher histodifferentiation specimens were higher than that in lower histodifferentiation specimens (P<0.05). Moreover, the expression level of galectin-3 and VEGF was detected a statistical positive correlation (r=0.423, P<0.05) in LSCC. CONCLUSION: The high level expression of galectin-3 and VEGF in LSCC could play an important role in tumorous histodifferentiation and metastasis.