Evaluation of peri-plaque pericoronary adipose tissue attenuation in coronary atherosclerosis using a dual-layer spectral detector CT.

Purpose: This study aimed to evaluate the differences between pericoronary adipose tissue (PCAT) attenuation at different measured locations in evaluating coronary atherosclerosis using spectral computed tomography (CT) and to explore valuable imaging indicators. Methods: A total of 330 patients with suspicious coronary atherosclerosis were enrolled and underwent coronary CT angiography with dual-layer spectral detector CT (SDCT). Proximal and peri-plaque fat attenuation index (FAI) of stenosis coronary arteries were measured using both conventional images (CIs) and virtual monoenergetic images (VMIs) ranging from 40 keV to 100 keV. The slopes of the spectral attenuation curve (λ) of proximal and peri-plaque PCAT at three different monoenergetic intervals were calculated. Additionally, peri-plaque FAI on CI and virtual non-contrast images, and effective atomic number were measured manually. Results: A total of 231 coronary arteries with plaques and lumen stenosis were finally enrolled. Peri-plaque FAICI and FAIVMI were significantly higher in severe stenosis than in mild and moderate stenosis (p < 0.05), while peri-plaque λ, proximal FAI, and proximal λ were not statistically different. Proximal FAI, peri-plaque FAI, and peri-plaque λ were significantly higher in low-density non-calcified plaque (LD-NCP) and non-calcified plaque (NCP) than in calcified plaque (p < 0.01). Peri-plaque FAI was the highest in the LD-NCP group, while proximal FAI was the highest in the NCP group. In severe stenosis and in LD-NCP, peri-plaque FAI was significantly higher than proximal FAI (p < 0.05). The manually measured parameters related to peri-plaque PCAT attenuation had a positive correlation with the results of peri-plaque FAI measured automatically. Conclusion: Peri-plaque PCAT has more value in assessing coronary atherosclerosis than proximal PCAT. Peri-plaque PCAT attenuation is expected to be used as a standard biomarker for evaluating plaque vulnerability and hemodynamic characteristics.

Tumor Cell-Derived Exosomal miR-191-5p Activates M2-Subtype Macrophages Through SOCS3 to Facilitate Breast Cancer.

Differential activation of macrophages is associated with poor progression of breast cancer (BC). Many reports have elucidated the important involvement of exosomes produced by cancer cells in remodeling the macrophage activation phenotype to promote tumor expansion and invasion. However, the underlying mechanisms by which exosomes secreted by BC cells facilitate macrophage M2 polarization remain enigmatic and worth exploring. In this study, quantitative real-time PCR (RT-qPCR) was used to investigate miR-191-5p expression in BC tumor tissues and cells. Cell counting kit 8 (CCK-8), transwell, and flow cytometry were applied to assess the functional role of miR-191-5p in BC. Isolated nano-vesicles were identified using transmission electron microscopy and western blotting. We also observed that miR-191-5p was significantly elevated in BC clinical samples and that inhibition of miR-191-5p hindered the growth and metastasis of BC cells. Importantly, BC cells successfully accelerated macrophage M2-like polarization by directly transferring exosomes to macrophages, resulting in increased miR-191-5p levels in macrophages. Mechanistically, exosomal miR-191-5p directly inhibited the suppressors of cytokine signaling 3 (SOCS3) expression in macrophages and aggravated macrophage M2 polarization. Similarly, si-SOCS3 transfected macrophages boosted BC cell migration and invasion in a positive feedback manner. Overall, our results manifested a pro-growth and pro-metastatic role between the two cells by elucidating the crucial role of exosomal miR-191-5p in stimulating M2 macrophage polarization and mediating communication between BC cells and macrophages. These findings opened up new horizons for the development of BC therapeutic strategies.

The value of CT-based radiomics in predicting the prognosis of acute pancreatitis.

Purpose: Early judgment of the progress of acute pancreatitis (AP) and timely intervention are crucial to the prognosis of patients. The purpose of this study was to investigate the application value of CT-based radiomics of pancreatic parenchyma in predicting the prognosis of early AP. Materials and methods: This retrospective study enrolled 137 patients diagnosed with AP (95 cases in the progressive group and 42 cases in the non-progressive group) who underwent CT scans. Patients were randomly divided into a training set (n = 95) and a validation set (n = 42) in a ratio of 7: 3. The region of interest (ROI) was outlined along the inner edge of the pancreatic parenchyma manually, and the Modified CT Severity Index (MCTSI) was assessed. After resampling and normalizing the CT image, a total of 2,264 radiomics features were extracted from the ROI. The radiomics features were downscaled and filtered using minimum redundancy maximum correlation (mRMR) and the least absolute shrinkage and selection operator algorithm (LASSO) regression, in turn, and the more optimal subset of radiomics features was selected. In addition, the radiomics score (rad-score) was calculated for each patient by the LASSO method. Clinical data were also analyzed to predict the prognosis of AP. Three prediction models, including clinical model, radiomics model, and combined clinical-radiomics model, are constructed. The effectiveness of each model was evaluated using receiver operating characteristic (ROC) curve analysis. The DeLong test was employed to compare the differences between the ROC curves. The decision curve analysis (DCA) is used to assess the net benefit of the model. Results: The mRMR algorithm and LASSO regression were used to select 13 radiomics features with high values. The rad-score of each texture feature was calculated to fuse MCTSI to establish the radiomics model, and both the clinical model and clinical-radiomics model were established. The clinical-radiomics model showed the best performance, the AUC and 95% confidence interval, accuracy, sensitivity, and specificity of the clinical-radiomics model in the training set were 0.984 (0.964-1.000), 0.947, 0.955, and 0.931, respectively. In the validation set, they were 0.942 (0.870-1.000), 0.929, 0.966, and 0.846, respectively. The Delong test showed that the predictive efficacy of the clinical-radiomics model was higher than that of the clinical model (Z = 2.767, p = 0.005) and the radiomics model (Z = 2.033, p = 0.042) in the validation set. Decision curve analysis demonstrated higher net clinical benefit for the clinical-radiomics model. Conclusion: The pancreatic parenchymal CT clinical-radiomics model has high diagnostic efficacy in predicting the progression of early AP patients, which is significantly better than the clinical or radiomics model. The combined model can help identify and determine the progression trend of patients with AP and improve the prognosis and survival of patients as early as possible.

Predicting coronary atherosclerosis heart disease with pericoronary adipose tissue attenuation parameters based on dual-layer spectral detector computed tomography: a preliminary exploration.

Background: Coronary atherosclerosis is a chronic inflammatory condition. Pericoronary adipose tissue (PCAT) attenuation is closely related to coronary inflammation. This study aimed to investigate the relationship between PCAT attenuation parameters and coronary atherosclerotic heart disease (CAD) using dual-layer spectral detector computed tomography (SDCT). Methods: This cross-sectional study included eligible patients who underwent coronary computed tomography angiography using SDCT at the First Affiliated Hospital of Harbin Medical University between April 2021 and September 2021. Patients were classified as CAD (with coronary artery atherosclerotic plaque) or non-CAD (without coronary artery atherosclerotic plaque). Propensity score matching was used to match the two groups. The fat attenuation index (FAI) was used to quantify PCAT attenuation. The FAI was measured on conventional images (120 kVp) and virtual monoenergetic images (VMI) by semiautomatic software. The slope of the spectral attenuation curve (λ) was calculated. Regression models were established to evaluate the predictive value of PCAT attenuation parameters for CAD. Results: A total of 45 patients with CAD and 45 patients without CAD were enrolled. The PCAT attenuation parameters in the CAD group were significantly higher than those in the non-CAD group (all P values <0.05). The PCAT attenuation parameters of vessels with or without plaques in the CAD group were higher than those of vessels without plaques in the non-CAD group (all P values <0.05). In the CAD group, the PCAT attenuation parameters of vessels with plaques were slightly higher than those of vessels without plaques (all P values >0.05). In receiver operating characteristic curve analysis, the FAIVMI model achieved an area under the curve (AUC) of 0.8123 for discriminating between patients with and without CAD, which was higher than those of the FAI120 kVp model (AUC =0.7444) and the λ model (AUC =0.7230). However, the combined model of FAIVMI, FAI120 kVp, and λ obtained the best performance (AUC =0.8296) of all the models. Conclusions: PCAT attenuation parameters obtained using dual-layer SDCT can aid in distinguishing patients with and without CAD. By detecting increases in PCAT attenuation parameters, it might be possible to predict the formation of atherosclerotic plaques before they appear.

Silencing of circHIPK3 Sensitizes Paclitaxel-Resistant Breast Cancer Cells to Chemotherapy by Regulating HK2 Through Targeting miR-1286.

BACKGROUND: Resistance development to paclitaxel (PTX) has become a major obstacle in the successful treatment of breast cancer (BC). Circular RNAs (circRNAs) have been identified as essential regulators in PTX resistance of BC. Here, we explored the precise roles of circRNA homeodomain interacting protein kinase 3 (circHIPK3, circ_0000284) in PTX resistance of BC. METHODS: The expression levels of circHIPK3, microRNA (miR)-1286, and hexokinase 2 (HK2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Ribonuclease R (RNase R) assay was used to confirm the stability of circHIPK3. Cellular localization of circHIPK3 was assessed by subcellular localization assay. The half maximal inhibitory concentration (IC50) value for PTX was measured by Cell Counting Kit-8 (CCK-8) assay. Cell colony formation, cell cycle distribution, and apoptosis were gauged by colony formation assay and flow cytometry, respectively. Animal studies were performed to evaluate the role of circHIPK3 in vivo. The direct relationship between miR-1286 and circHIPK3 or HK2 was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. RESULTS: Our results showed that circHIPK3 was up-regulated in PTX-resistant BC tissues and cells compared with the sensitive counterparts. The silencing of circHIPK3 promoted PTX sensitivity of PTX-resistant BC cells in vitro and in vivo. CircHIPK3 directly targeted miR-1286, and miR-1286 acted as a downstream mediator of circHIPK3 function in vitro. HK2 was a direct target of miR-1286, and circHIPK3 modulated HK2 expression through miR-1286. The increased expression of miR-1286 sensitized PTX-resistant BC cells to PTX in vitro by down-regulating HK2. CONCLUSION: Our findings demonstrated that the silencing of circHIPK3 sensitized PTX-resistant BC cells to PTX therapy at least in part via the regulation of the miR-1286/HK2 axis.

CT-derived abdominal adiposity: Distributions and better predictive ability than BMI in a nationwide study of 59,429 adults in China.

BACKGROUND: Although abdominal adiposity is associated with an altered cardiometabolic risk profile, the specific contribution of abdominal adipose tissue distribution remains not fully understood. Computed tomography (CT) is a well-established and precise method to measure abdominal adipose tissue distribution. The present study investigated abdominal adiposity assessed by CT in a large-scale Chinese population. METHOD: A total of 59,429 adults who underwent a low dose chest CT for lung cancer screening at one of 13 health checkup centers throughout China were evaluated. Abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured at the center of the 2nd lumbar vertebra with Mindways quantitative CT software using the existing CT dataset without any additional radiation exposure. The ratio of visceral to total adipose tissue (TAT) areas (VAT/TAT ratio) was calculated and expressed as a percentage. Anthropometric indices including body mass index (BMI) and waist circumference were also obtained. RESULTS: BMI, waist circumference, VAT area, SAT area, and the VAT/TAT ratio were 25.0 ±â€¯3.0 kg/m2, 90 ±â€¯8 cm, 194 ±â€¯77 cm2, 85 ±â€¯41 cm2, and 69.5 ±â€¯9.1%, respectively, in men and 23.3 ±â€¯3.1 kg/m2, 79 ±â€¯8 cm, 120 ±â€¯57 cm2, 123 ±â€¯53 cm2, and 48.9 ±â€¯9.7% in women. With increasing age, VAT area and the VAT/TAT ratio increased in both sexes whereas SAT area decreased in men (P < 0.001 for all). After adjustment for BMI and waist circumference, older individuals showed higher VAT area and higher VAT/TAT ratio than younger subjects (P < 0.001 for all). Adjusted VAT areas in participants aged 75 or older was 45 cm2 (95% confidence interval [CI]: 41 cm2, 50 cm2) higher in men and 43 cm2 (95% CI: 37 cm2, 49 cm2) higher in women compared with participants aged 31-44 years. Additionally, differences in VAT area across age groups increased as BMI or waist circumference increased. VAT and SAT areas, but not the VAT/TAT ratio, were positively associated with BMI and waist circumference in every age group. CONCLUSION: In a nationwide study conducted in China, distributions of CT-derived measures of visceral and subcutaneous adiposity were found to vary significantly between sex and age groups. Our study also revealed that the proportion of VAT (an important driver of cardiometabolic risk) could not be predicted from BMI in a Chinese population.

Opportunistic Screening Using Low-Dose CT and the Prevalence of Osteoporosis in China: A Nationwide, Multicenter Study.

Opportunistic screening for osteoporosis can be performed using low-dose computed tomography (LDCT) imaging obtained for other clinical indications. In this study we explored the CT-derived bone mineral density (BMD) and prevalence of osteoporosis from thoracic LDCT in a large population cohort of Chinese men and women. A total of 69,095 adults (40,733 men and 28,362 women) received a thoracic LDCT scan for the purpose of lung cancer screening between 2018 and 2019, and data were obtained for analysis from the China Biobank Project, a prospective nationwide multicenter population study. Lumbar spine (L1 -L2 ) trabecular volumetric bone mineral density (vBMD) was derived from these scans using quantitative computed tomography (QCT) software and the American College of Radiology QCT diagnostic criteria for osteoporosis were applied. Geographic regional differences in the prevalence of osteoporosis were assessed and the age-standardized, population prevalence of osteoporosis in Chinese men and women was estimated from the 2010 China census. The prevalence of osteoporosis by QCT for the Chinese population aged >50 years was 29.0% for women and 13.5% for men, equating to 49.0 million and 22.8 million, respectively. In women, this rate is comparable to estimates from dual-energy X-ray absorptiometry (DXA), but in men, the prevalence is double. Prevalence varied geographically across China, with higher rates in the southwest and lower rates in the northeast. Trabecular vBMD decreased with age in both men and women. Women had higher peak trabecular vBMD (185.4 mg/cm3 ) than men (176.6 mg/cm3 ) at age 30 to 34 years, but older women had lower trabecular vBMD (62.4 mg/cm3 ) than men (92.1 mg/cm3 ) at age 80 years. We show that LDCT-based opportunistic screening could identify large numbers of patients with low lumbar vBMD, and that future cohort studies are now required to evaluate the clinical utility of such screening in terms of fracture prevention and supporting national health economic analyses. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)..

A Rapid, Accurate and Machine-Agnostic Segmentation and Quantification Method for CT-Based COVID-19 Diagnosis.

COVID-19 has caused a global pandemic and become the most urgent threat to the entire world. Tremendous efforts and resources have been invested in developing diagnosis, prognosis and treatment strategies to combat the disease. Although nucleic acid detection has been mainly used as the gold standard to confirm this RNA virus-based disease, it has been shown that such a strategy has a high false negative rate, especially for patients in the early stage, and thus CT imaging has been applied as a major diagnostic modality in confirming positive COVID-19. Despite the various, urgent advances in developing artificial intelligence (AI)-based computer-aided systems for CT-based COVID-19 diagnosis, most of the existing methods can only perform classification, whereas the state-of-the-art segmentation method requires a high level of human intervention. In this paper, we propose a fully-automatic, rapid, accurate, and machine-agnostic method that can segment and quantify the infection regions on CT scans from different sources. Our method is founded upon two innovations: 1) the first CT scan simulator for COVID-19, by fitting the dynamic change of real patients' data measured at different time points, which greatly alleviates the data scarcity issue; and 2) a novel deep learning algorithm to solve the large-scene-small-object problem, which decomposes the 3D segmentation problem into three 2D ones, and thus reduces the model complexity by an order of magnitude and, at the same time, significantly improves the segmentation accuracy. Comprehensive experimental results over multi-country, multi-hospital, and multi-machine datasets demonstrate the superior performance of our method over the existing ones and suggest its important application value in combating the disease.

Gemstone spectral imaging in lung cancer: A preliminary study.

The present study aimed to evaluate the application of gemstone spectral imaging (GSI) for multi-parameter quantitative measurement in lung cancer.The study retrospectively enrolled 30 patients with lung cancer who underwent chest contrast enhanced CT scan with GSI mode. The GSI viewer was used for image display and data analysis. Optimal energy value, CT values at 40 keV, 70 keV and optimal energy level, spectral curve slope, effective atomic number (Zeff), iodine concentration (IC), and water concentration (WC) at the region of interest were measured and analyzed by statistical methods.The optimal energy value for optimal contrast-to-noise ratio on plain scan, arterial phase and venous phase was 62.2 ±â€Š5.38 keV, 50.63 ±â€Š3.84 keV, and 52.5 ±â€Š3.7 keV, respectively. There were significant differences in CT values at different energy levels on each scan phase (P = .033). The spectral curve slope values among 40 to 70 keV, 40 to 100 keV, and 40 to 140 keV were significantly different (P < .001). No significant difference with the slope between arterial phase and venous phase at each energy level interval was observed. Zeff on plain scan, arterial phase, and venous phase was 7.75 ±â€Š0.15, 8.38 ±â€Š0.37, and 8.38 ±â€Š0.30, respectively. Positive correlation was observed among IC, normalized IC, and Zeff on enhanced scan.Multiparameter of GSI can be used for lung tumor lesion evaluation. Different parameters were correlated and provide multiple qualitative and quantitative information together.

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography.

OBJECTIVE: This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. PATIENTS AND METHODS: First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. RESULTS: Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. CONCLUSION: The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging.

The Clinical Application of Mastectomy With Single Incision Followed by Immediate Laparoscopic-Assisted Breast Reconstruction With Latissimus Dorsi Muscle Flap.

OBJECTIVE: To explore the clinical application of mastectomy with single incision followed by immediate laparoscopic-assisted breast reconstruction with latissimus dorsi muscle flap. METHODS: Fifteen women with primary early breast cancer, 3 women with breast ductal carcinoma in situ, and 7 women with severe plasma cell mastitis were treated with partial mastectomy or total mastectomy, sentinel lymph node biopsy, or axillary lymph node dissection through a breast lateral transverse incision. Subsequent breast reconstruction with latissimus dorsi muscle flap was assisted by laparoscopy. The patient's position, time used in dissecting latissimus dorsi muscle flap, size of latissimus dorsi muscle flap, postoperative complications, and the cosmetic results after reconstruction were assessed. RESULTS: All the operations were well done through the breast lateral transverse incision and assistance of laparoscopy. The patient's position was changed only once during the operation. It took 1.5 to 2 hours to dissect latissimus dorsi muscle flap. The sizes of the latissimus dorsi muscle flap were 5 to 8 × 12 to 16 cm. There were no serious postoperative complications noted. The patients were satisfied with the appearance of the breasts and the small surgical scar. CONCLUSION: The surgical approach introduced is minimally invasive with concealed scar and outstanding cosmetic results. It is worth promoting in clinical application.

Gemstone spectral imaging reduced artefacts from metal coils or clips after treatment of cerebral aneurysms: a retrospective study of 35 patients.

OBJECTIVE: This study aimed to evaluate the effect of gemstone spectral imaging (GSI) for metal artefact reduction in cerebral artery CT angiography (CTA) after metal coils or clips treatment. METHODS: 35 patients with cerebral aneurysms were treated with metal coils or clips and underwent CTA using gemstone spectral CT between February and December 2013. The data were reconstructed into three image groups including Group A (quality check images with 140 kVp), Group B (monochromatic image sets in the range of 40-140 keV) and Group C [monochromatic image sets with metal artefacts reduction software (MARS GE Medical Systems, Waukesha, WI)]. CT attenuation value of cerebral artery, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and the subjective score of all images were measured and compared statistically. RESULTS: CT attenuation value of cerebral artery decreased in Groups B and C as the photon energy increased. The average energy levels of 60.05 ± 5.37 and 59.93 ± 5.57 keV presented the best CNR in Groups B and C, respectively. CNR values, SNR values and the subjective scores of the image quality of the two sets were higher than those of Group A. CONCLUSION: GSI reduced metal artefact and improved the image quality of CTA after metal coils or clips treatment in patients with cerebral aneurysm. The monochromatic images at the average energy level of 60.05 ± 5.37 keV with MARS and 59.93 ± 5.57 keV without MARS were suggested to be the optimal parameters. ADVANCES IN KNOWLEDGE: GSI could reduce metal artefact after metal coils or clips treatment in patients with cerebral aneurysm.

Imaging of acute superior mesenteric artery embolus using spectral CT in a canine model.

OBJECTIVE: To explore the diagnostic value of single-source dual-energy spectral CT (sDECT) imaging in an acute superior mesenteric artery embolus (SMAE) canine model. METHODS: Pre-contrast and double-phase contrast-enhanced sDECT were performed before and after embolization in eight SMAE dog models. Monochromatic images of embolized intestine with the best contrast-to-noise ratio (CNR) were obtained and compared with the polychromatic images. CT parameters including attenuation value, iodine content, water content and thickness of the embolized intestinal segments were obtained, and normalized difference in iodine concentration (NDIC) was calculated. RESULTS: The CNR in pre-contrast, arterial phase and portal venous phase at 4 h after embolization was 1.11 ± 1.23, 13.50 ± 1.54 and 10.63 ± 3.75, respectively, significantly higher than those of the polychromatic images (p < 0.05). The iodine-based images clearly revealed the embolized intestinal segments, which were highly consistent with the gross findings. The difference in attenuation values between the embolization area and non-embolization area in the monochromatic images was 105.06 ± 35.35 HU, higher than that in the polychromatic images (p < 0.001). The attenuation values and NDIC were significantly decreased at 2 h after embolization, relatively increased at 4 h and gradually decreased at 6 and 8 h. The changing pattern of thickness was similar to that of NDIC over time after embolization. CONCLUSION: sDECT can provide the optimal monochromatic images and allow increased detection rates of lesions. sDECT is a very promising tool for quantitative diagnosis of SMAE. ADVANCES IN KNOWLEDGE: Our research provides more quantitative parameters for the assessment of SMAE by sDECT.

Microvascular damage after coronary artery bypass surgery: assessment using dobutamine stress myocardial contrast echocardiography.

BACKGROUND: Although dobutamine stress myocardial contrast echocardiography (DSMCE) has been widely used for the prediction of myocardial functional recovery, dynamic changes that occur at the microcirculatory level during stress have been studied limitedly. The objective of the present study was to use low-dose DSMCE to assess microvascular damage and predict myocardial functional recovery in coronary artery disease (CAD) patients receiving coronary artery bypass grafting. METHODS: Forty-six CAD patients were subjected to low-dose DSMCE, as well as echocardiography and coronary computed tomography angiography before revascularization, 1 year after coronary artery bypass grafting. Dynamic changes occurring at the microcirculatory level during stress were analyzed for the ability to predict functional recovery. Quantitative assessment of functional recovery was determined using myocardial blood flow (MBF) via receiver operating characteristic curve analyses. RESULTS: Patients who failed to recover had fewer changes in MBF (ΔMBF) at rest and with stress compared with the segments showing functional recovery. Semiquantitative changes (enhanced or reduced) of the myocardial perfusion score (ΔMPS) and quantitative changes in ΔMBF of stress myocardial contrast echocardiography enhanced the specificity of resting MPS and the sensitivity of wall motion scores (P < 0.05) for the prediction of functional recovery. CONCLUSIONS: Specific stress ΔMBF more accurately reflected the extent of microvascular damage compared with wall motion scores and resting MPS. ΔMBF and ΔMPS under stress myocardial contrast echocardiography provided higher accuracy than wall motion scores and resting MPS in predicting functional recovery in CAD patients after revascularization.

Effect of graft patency on the prediction of myocardial viability by dobutamine stress and myocardial contrast echocardiography before coronary artery bypass surgery.

BACKGROUND: Myocardial functional recovery after revascularization is considered the "gold standard" for myocardial viability (MV) assessment. However, the patency of the revascularized coronary artery affects myocardial functional recovery in patients subjected to coronary artery bypass grafting (CABG). The influence of graft patency on viability results has not been widely studied. PURPOSE: We evaluated the effect of graft patency on the prediction of MV after CABG by myocardial contrast echocardiography (MCE) and low-dose dobutamine stress echocardiography (LD-DSE). METHODS: Fifty-three subjects with chronic ischemic heart disease scheduled for CABG were divided randomly into groups A (n = 26) and B (n = 27). They underwent MCE and LD-DSE preoperatively. Patients were followed up 12 months after CABG. Group B patients underwent multislice computed tomography angiography to assess CABG patency, and patients with obstructed grafts were excluded. Group A patients were not subjected to multislice CT angiography. The accuracy of MCE and LD-DSE for assessing MV between the two groups was compared. RESULTS: The accuracy and positive predictive values of MCE and LD-DSE for predicting MV were higher in group B than in group A (p < 0.05). CONCLUSIONS: Preoperative LD-DSE and MCE ability to predict MV depends on the patency of CABG.

Biomechanical effects of pedicle screw adjustments on the thoracolumbar burst fractures.

BACKGROUND: Posterior pedicle screw device is widely used in treatment of thoracolumbar burst fractures. As the clinical operation is not based upon quantitative data of adjustments, the results are not optimal. At present, no study has assessed the associations between the device adjustments and the restoration of stiffness. We investigated the biomechanical effects that adjustments of a pedicle screw device had on the burst fracture, and explored an optimal adjustment. METHODS: Burst fractures were produced at L1 vertebra in 24 fresh calf spines (T12-L3). The specimens were divided into four groups at random. Pedicle screw devices were attached to T13 and L2. Four device adjustments, consisting of distraction and extension, were applied. Adjustment 1 was pure 6° extension, adjustment 2 was pure 5 mm distraction, adjustment 3 was 6° extension followed by 5 mm distraction, and adjustment 4 was 5 mm distraction followed by 6° extension. The effect of each adjustment on the stiffness restoration, anatomical reduction, and neural decompression for the burst fractures was analyzed and evaluated. RESULTS: Pure extension (Group 1) produced the closest segment height and the least restoration of the canal to the intact. Pure distraction (Group 2) restored stiffness most, but with only 60% stiffness of the intact value, and lost the segmental angle most to the intact. The combination of extension-distraction (Group 3 and Group 4) produced the maximum reduction of the anatomy and restoration of the canal in the burst fracture, and the least stiffness restoration. The sequence of extension and distraction did not affect stiffness restoration, anatomical reduction, and neural decompression. CONCLUSIONS: The device adjustments affected stiffness restoration, anatomical reduction, and neural decompression. The combined extension-distraction adjustment may be the most suitable considering the anatomical reduction and neural decompression, but the stiffness decreased the most; it should be considered to reconstruct L1 vertebra.

Downregulation of pancreatic-duodenal homeobox 1 expression in breast cancer patients: a mechanism of proliferation and apoptosis in cancer.

Pancreatic-duodenal homeobox 1 (PDX-1) is a transcription factor that regulates embryological pancreas development and insulin expression in adult islets. The current study investigated the expression profile and potential role of PDX-1 in breast cancer. Immunohistochemistry was performed to determine the expression pattern of PDX-1 in breast cancer and adjacent benign breast tissues. In addition, cell proliferation and the cell cycle were evaluated following the transient inhibition of PDX-1 with antisense oligonucleotides in MCF-7 human breast cancer cells. Real-time PCR and western blotting were conducted to investigate the correlation between PDX-1, P53, Ki-67, Caspase 3 and Caspase 8. These experiments demonstrated that PDX-1 was downregulated in human breast cancer tissue compared with adjacent normal breast tissue. Knockdown of PDX-1 expression in vitro in MCF-7 breast cancer cells promoted cell proliferation and disrupted the cell cycle, as demonstrated by the overexpression of P53 and Ki-67 at the mRNA and protein levels. In conclusion, the current study shows that PDX-1 regulates cell proliferation and the cell cycle in human breast cancer cells by altering the expression of the cell cycle-related genes, P53 and Ki-67. These data suggest that PDX-1 is a putative tumor suppressor in breast cancer.

miR-497 induces apoptosis of breast cancer cells by targeting Bcl-w.

microRNAs are a small class of non-coding RNAs with a critical role in the tumorigenesis and maintenance of breast cancer through binding to the 3'-untranslated regions of target mRNAs, which causes a block of translation and/or mRNA degradation. The purpose of this study was to investigate the expression of microRNA-497 (miR-497) as well as its potential role in human breast cancer. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to determine the expression pattern of miR-497 in breast cancer and normal breast tissues. Correlation analysis was conducted to characterize the association of miR-497 expression abnormality with pathological factors. Proliferation, cell cycle and apoptosis assays were conducted to explore the potential function of miR-497 in human MCF-7 breast cancer cells. RT-PCR and Western blot analysis were employed to validate the downstream targets of miR-497. miR-497 expression was relatively decreased in breast cancer specimens and negatively correlated with TNM stage, lymphatic metastasis, tumor size and human epidermal growth factor receptor-2 (P<0.01). On the contrary, no correlation was found with estrogen receptor, progesterone receptor and p53 status. Functional assays revealed that miR-497 suppressed cellular growth, increased the percentage of early apoptotic cells and initiated G0/G1 cell phase arrest of MCF-7 cancer cells. RT-PCR and Western blot analysis data indicated that the overexpression of miR-497 resulted in the down-regulation of Bcl-w at the mRNA and protein levels. miR-497 may serve as a tumor suppressor gene in breast cancer. The Up-regulation of miR-497 expression causes cellular growth inhibition and apoptotic enhancement, as well as G0/ G1 phase arrest, suggesting its use as a potential therapeutic target for the treatment of breast cancer in the future.

The expression and effects the CABYR-c transcript of CABYR gene in hepatocellular carcinoma.

BACKGROUND AND AIM: CABYR, a calcium-binding tyrosine phosphorylation regulated fibrous sheath protein, was initially reported to be testis-specific and subsequently shown to be present in brain tumors, pancreas cancer and lung cancer. This study aimed to investigate the expression and effects of the CABYR-c transcript of CABYR gene in hepatocellular carcinoma. METHODS: mRNA and protein expression of CABYR-c was examined in 20 paired hepatocellular carcinoma tissues and adjacent non-cancerous tissues by real-time quantitative RT-polymerase chain reaction (PCR) and western blot analysis respectively. HepG2 cells were treated with the antisense oligodeoxynucleotides targeting CABYR-c mRNA (CABYR-c antisense oligonucleotides [AS ODNs]) for indicated times, the AS ODNs inhibition effect was evaluated by measuring the CABYR-c mRNA expression level of HepG2 cells after treatment using real-time quantitative RT-PCR, then cell proliferation was studied using MTT assay, and cell cycle distribution and apoptosis were detected by flow cytometry as well. RESULTS: CABYR-c mRNA levels in hepatocellular carcinoma tissues were significantly higher than that in the paired adjacent non-cancerous tissues (27.5 ± 1.2 versus 2.5 ± 0. 9, P < 0.01). CABYR-c protein expression level in hepatocellular carcinoma tissues was also significantly higher than that in adjacent non-cancerous tissues. CABYR-c mRNA expression in HepG2 cells was most effective down-regulated after treatment of 600 nM CABYR-c AS ODNs for 48 h, which was selected for subsequent experiments. Incubation with 600 nM CABYR-c AS ODNs inhibited the cell growth of HepG2 cells in a dose- and time-dependent manner. The maximum inhibitory effect achieved at 600 nM after 72 h treatment (30.92 ± 3.25%, P < 0.01). HepG2 cells treated 600 nM CABYR-c AS ODNs for 48 h exhibited an increasing proportion of cells in G0/G1 phase (P < 0.05) and a decreasing proportion of cells in S phase (P < 0.05), compared with untreated controls. No obvious differences were observed in G2/M phase. The fraction of apoptotic HepG2 cells in CABYR-c AS ODNs treated group was less than that of untreated control group (P < 0.05). CONCLUSION: CABYR-c is highly expressed in hepatocellular carcinoma tissues and may play an oncogenic role in heptocarcinogenesis as well as its progression.