Bing Hu

Differentially expressed microRNAs and their target genes in the hearts of streptozotocin-induced diabetic mice.

Persistent hyperglycemia in diabetic patients has been associated with cardiac hypertrophy, myocardial fibrosis and cardiac dysfunction. However, the underlying mechanisms of this association have yet to be fully elucidated. The aim of this study was to investigate the expression and function of microRNAs (miRNAs) in diabetic cardiomyopathy. miRNA expression profiles were examined by miRNA microarray analysis in heart tissue from streptozotocin (STZ)-induced diabetic mice and non-diabetic mice. The targets of the altered miRNAs were predicted using the Sanger database. Then, the targets RASA1, RAC1, TGFB3 and COL1A1, related to cardiac hypertrophy or myocardial fibrosis, were selected to analyze the miRNA level by real-time reverse transcription (RT-PCR). Gene Ontology (GO) was further applied to describe the function of each miRNA target gene and to elucidate their combined effects in diabetic cardiomyopathy. Up-regulated (n=10) and down-regulated (n=6) miRNAs were identified in diabetic cardiomyopathy. Target genes (n=192) were pooled from the Sanger database. Among the 192 targets, the mRNA expression of RASA1, RAC1, TGFB3 and COL1A1 was increased in diabetic cardiomyopathy. Thirty one GO functions were enriched in diabetic cardiomyopathy. These results demonstrate that miRNAs may mediate cardiac hypertrophy and myocardial fibrosis in diabetic cardiomyopathy via their targets, and provide insights into the pathogenesis of diabetic cardiomyopathy.

Contrast-enhanced ultrasound versus conventional ultrasound in the diagnosis of polypoid lesion of gallbladder: A multi-center study of dynamic microvascularization

OBJECTIVEnTo assess the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of polypoid lesions of gallbladder (PLGs).nnnMETHODSnCEUS was performed to 116 patients (mean age, 49.6 years; range, 21-80 years) with PLGs from 8 university hospitals. 9 cases of biliary sludge were proven by surgery and the remaining 107 cases were confirmed by histopathological examination. The confidence level, diagnostic performance, inter-observer agreement of two independent readers with different experience was assessed. The readers were blind to the imaging and clinical results of the patients.nnnRESULTSnThere were significant differences between benign and malignant PLGs in patient age, gender, lesion size, echogenicity, stalk, time-to-peak, vascularity on CEUS, enhancement pattern, and wall destruction. The confidence levels increased significantly and the interobserver agreement increased from 0.425 to 0.601 after CEUS. The sensitivity increased from 22.2 to 77.8% after CEUS in the staff radiologist, and from 22.2 to 66.7% in the resident radiologist. The correctly characterized lesions were 64.7% before versus 87.1% after CEUS (P=0.125) for the staff radiologist, and 57.8% versus 70.7% for the resident radiologist (P=0.007). No significance was found in the subgroup of lesions≤1.0 cm before and after CEUS for the two radiologists.nnnCONCLUSIONSnCEUS using convex multifrequency probes could detect the dynamic microvascularization of PLGs greater than 1.0 cm and facilitate the differentiation between benign and malignant tumors.

Imaging and Analyzing the Elasticity of Vascular Smooth Muscle Cells by Atomic Force Acoustic Microscope

Vascular smooth muscle cells (VSMCs) play an important role in the good performance of the vasculature. To study the surface, intracellular structure and elasticity of VSMCs, atomic force acoustic microscope (AFAM) was used for imaging VSMCs from A7r5 rat aorta arteries. The topography images of VSMCs were obtained in contact mode and the acoustic images were obtained by AFAM in sample vibration mode. Then, the force curve measurement derived using Youngs modulus of the interested areas was used for evaluating elasticity properties. The acoustic images were found in higher resolution with more information than the topography images. The force curves showed the difference in Youngs modulus of the different parts of VSMC. These findings demonstrate that AFAM is useful for displaying the surface, structure and elasticity property of VSMCs clearly, with short scanning time, negligible harm or damage to cell and nanometer-level resolution.

Diagnostic value of contrast-enhanced ultrasound in solid thyroid nodules with and without enhancement

AbstractnWe aimed to investigate different enhancement patterns of solid thyroid nodules on contrast-enhanced ultrasound (CEUS) and then to evaluate the corresponding diagnostic performance in the differentiation of benign and malignant nodules with and without enhancement. 229 solid thyroid nodules in 196 patients who had undergone both conventional ultrasound and CEUS examinations were classified into enhancement and non-enhancement groups. Besides, different enhancement patterns in the enhancement group were characterised with five indicators including arrival time, mode of entrance, echo intensity, homogeneity, and washout time. Then aforementioned indicators were compared between benign and malignant nodules of different sizes (<10xa0mm and >10xa0mm), and diagnostic performance of significant enhancement indicators was calculated. As for the enhancement group, there were statistically significant differences of <10xa0mm subgroup among three CEUS indicators including arrival time, mode of entrance, and washout time between malignant and benign thyroid nodules (pxa0<xa00.05), while all CEUS indicators showed statistically significant differences in the total group and ≥10xa0mm subgroup (pxa0<xa00.05). All the five CEUS indicators displayed better diagnostic performance with specificity (92.86, 92.14, 95.71, 90.71, and 90.71xa0%, respectively) and diagnostic accuracy (80.79, 79.48, 74.67, 75.11, and 81.66xa0%, respectively), while the sensitivity and negative predictive value of non-enhancement were 95.51 and 95.83xa0%, respectively, with an accuracy of 77.29xa0%. CEUS is a very promising diagnostic technique that could improve the diagnostic accuracy of identifying benign thyroid lesions to spare a large number of patients an unnecessary invasive procedure.

Power Doppler ultrasonography in the evaluation of infliximab treatment for sacroiliitis in patients with ankylosing spondylitis

The aim of this study was to evaluate the feasibility of using power Doppler ultrasound (PDUS) to detect changes in the sacroiliac joint regions after infliximab (an anti-TNF-α blocker) treatment in active axial ankylosing spondylitis (AS) patients. A total of 110 sacroiliac joints in 55 patients with active AS were detected by PDUS before and after the infliximab treatment. The color flow signals inside the sacroiliac joints were observed, and the resistance index (RI) was measured. The clinical condition of the AS patients was improved compared with their condition before the infliximab treatment. Before the treatment, color flow signals were observed in 103 joints, and the mean RI value was 0.56xa0±xa00.06. Three months after the first infliximab treatment, color flow signals were observed in 50 joints, and the mean RI value was 0.87xa0±xa00.11. There were more blood flow signals in the sacroiliac joints before the infliximab treatment in patients with active AS (pxa0<xa00.01), and the mean RI value was higher after the infliximab treatment (pxa0<xa00.01). The blood flow signals in the sacroiliac joints became weaker or even disappeared and the RI values increased in patients with active sacroiliitis after infliximab treatment. This result shows that PDUS can be used in the follow-up of patients with axial AS.

Overexpression of HSP27 in cultured human aortic smooth muscular cells reduces apoptosis induced by low-frequency and low-energy ultrasound by inhibition of an intrinsic pathway.

We investigated in vitro the effect of low-frequency and low-energy ultrasound (LFLEU) on apoptosis of an overexpressed HSP27 human aortic smooth muscle cell (HASMC) line. A frequency of 42.6 kHz was used in all experiments. HASMC were exposed to ultrasound and cell viability was evaluated by MTT reduction. Overexpressed HSP27-HASMC was constructed on a pcDNA3.1 vector. Apoptosis was determined 24 h after treatment by flow cytometry; gene display was evaluated with Affimax chips, and HSP27 mRNA and protein expression levels were measured by RT-PCR and Western blotting. The apoptosis rate (at 30 s) was significantly lower in HASMC transfected with HSP27 (7.14 ± 1.73%), compared with cells transfected with a mock plasmid (17.31 ± 2.72%) or a control group (14.23 ± 2.77%), indicating a protective function for apoptosis induced by LFLEU. Gene display analysis showed that caspase-9 expression in HSP27 cell lines was downregulated and caspase-3 upregulated. However, RT-PCR and Western blotting analysis indicated that both caspase-9 and caspase-3 were inhibited at both the mRNA and protein levels. We suggest that overexpressed HSP27 is capable of protecting the LFLEU from apoptosis and that the pathway for this protection is via downregulated caspase-9 and caspase-3 expression.

Papillary thyroid microcarcinoma co-exists with Hashimoto’s thyroiditis: Is strain elastography still useful?

To study the performance of strain elastography in differentiating papillary thyroid microcarcinoma (PTMC) combined with Hashimotos thyroiditis (HT), conventional ultrasound scan (US) and strain elastography (SE) were performed on 558 nodules smaller than 10 mm by one examiner before surgeries. Serum concentrations of thyroid peroxidase antibody (TPO-Ab) (normal range: 0-60 U/ml) were measured. Continuous variables were analyzed by independent t test. Receiver operating characteristics (ROC) curve analysis was applied to calculate the cut-off values of strain ratio (SR) and elastography score (ES). The comparison of AUCs is performed by Z test. 482 nodules were diagnosed as PTMC and there were 181 nodules co-existed with HT. SR measurements were lower in PTMC co-existed with HT when comparing to those without HT. (7.292±6.581 vs 11.319±13.155, p<0.000). Taking the data from all of the 558 nodules, the best cut-off of diagnosing PTMC was SR>2.58. When taking the data from 181 PTMC with HT, the best cut-off was SR>2.10. The diagnostic value of SR>2.1 were higher than ES>3, conventional US and combining US and SE (z=3.595, 4.876, 4.420, p<0.001), but cut-off of SR>2.1 did not show significant enhancement of diagnostic value compared to SR>2.58 (z=0.439, p=0.8903>0.001) in PTMC with HT. There is a negative relation between SR and titer of TPO-Ab (r=-0.650, p<0.0001). PTMC with high TPO-Ab (>1000) titer presented lower SR (5.972±4.118 vs 8.379±9.172, p=0.009). Although SR measurements were lower in nodules co-existed with HT when comparing those without HT, using a regular ES and cut-off of SR measurement would not influence the diagnosing performance. SE is still very useful for diagnosing PTMC with HT. PTMC with high TPO-Ab titer might require a lower cut-off of SR.

Transforming Growth Factor β1 Could Influence Thyroid Nodule Elasticity and Also Improve Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma

Ultrasound elastography has been a very useful tool in predicting the risk of malignant thyroid tumor for several years. The objective of this study was to determine if there is a correlation between strain ratio (SR), collagen deposition and transforming growth factor β1 (TGF-β1) expression in different types of thyroid nodules and if TGF-β1 is related to cervical lymph node metastasis. 102 nodules from 81 patients who underwent thyroid resection surgery in our hospital were retrospectively studied. All of these patients had undergone ultrasound elastography scanning before surgery. Masson staining and immunohistochemical staining were used to evaluate the ratio of expression of collagen deposition and TGF-β1. There was a significant difference between benign and malignant thyroid nodules in SR (8.913 ± 11.021 vs. 1.732 ± 0.727, p = 0.000), collagen content (0.371 ± 0.125 vs. 0.208 ± 0.057, p = 0.000) and TGF-β1 expression (0.336 ± 0.093 vs. 0.178 ± 0.071, p = 0.000). A cutoff of 2.99 for SR measurement was selected for the highest Youden index for predicting malignant thyroid nodules, which yielded 87.88% sensitivity, 100% specificity, 100% positive predictive value, 83.72% negative predictive value and 92.15% accuracy. Expression of collagen and TGF-β1 was positively correlated with SR measurements (coefficient = 0.839 for collagen and 0.855 for TGF-β1, p = 0.000). Among 61 nodules with papillary thyroid carcinoma, the average SR for the metastasis group was higher than that for the non-metastasis group (10.955 ± 13.805 and 7.852 ± 7.931, respectively), but without statistical significance (p = 0.287). Collagen deposition was significantly higher in the metastasis group than in the non-metastasis group (0.421 ± 0.091 vs. 0.353 ± 0.118, p = 0.011). TGF-β1 expression was also significantly higher in the metastasis group than in the non-metastasis group (0.378 ± 0.0.69 vs. 0.328 ± 0.091, p = 0.016). To conclude, TGF-β1 may contribute to thyroid nodule elasticity by promoting collagen deposition. In papillary thyroid carcinoma, overexpression of TGF-β1, as well as collagen deposition, may be a risk factor for cervical lymph node metastasis.

Low-frequency low energy ultrasound combined with microbubbles induces distinct apoptosis of A7r5 cells

The present study aimed to investigate whether low frequency low energy ultrasound combined with microbubbles induces apoptotic cell death of A7r5 rat aortic vascular smooth muscle cells, and to identify the possible mechanisms underlying this effect. Ultrasonic waves (45 kHz with 0.3 Wcm2 of intensity for 0, 10, 20 and 30 sec) were used together with different dosages of SonoVue™ microbubbles (0, 14, 28, 42 and 56 µl), respectively. The cell viability and apoptotic rate were determined by trypan blue staining immediately following treatment and flow cytometry 24 h thereafter. The treatment conditions resulting in the lowest amount of necrosis, highest apoptotic rate and lowest microbubble dosage was selected for the US+MB group, which was treated with ultrasound combined with microbubbles. The cell proliferation 24 h following treatment was determined and western blot analysis was applied to examine the expression of apoptosis‑associated proteins, B-cell lymphoma 2 (Bcl‑2) and Bcl-2-associated X (Bax). The harmonic acoustic pressure amplitude was measured to obtain the cavitation intensity. The combination of 20 sec ultrasound irradiation and 14 µl SonoVue™ was selected as the treatment conditions for the US+MB group. The results demonstrated that both ultrasound alone (the US group) and in combination with microbubbles significantly inhibited the proliferation of A7r5 cells compared with that of the control (P<0.01), and the suppression in the US+MB group was significantly greater (P<0.01). The apoptotic rate in A7r5 cells induced by this combination treatment (16.62±0.93%) was significantly higher than that in the control (3.93±0.39%; P<0.01) and US (6.88±1.87%; P<0.01) groups. Treatment with ultrasound combined with microbubbles increased the expression of Bax and decreased the ratio of Bcl‑2/Bax compared with those in the control and US groups. The cavitation induced by ultrasound combined with microbubble treatment was more intense than that by ultrasound alone. The results demonstrated that the cell death and apoptosis of A7r5 cells were associated with ultrasound duration and microbubble dosage. Low frequency ultrasound combined with microbubbles induced apoptosis in A7r5 cells through the upregulation of Bax and the downregulation of the Bcl‑2/Bax ratio, where the cavitation effect may have an important role.

Contrast imaging and gene delivery through the combined use of novel cationic liposomal microbubbles and ultrasound in rat carotid arteries.

Introduction Lipid-coated cationic microbubbles represent a new class of agents with both diagnostic and therapeutic applications. The main goal of this study was to evaluate the efficiency of gene transfer through the combined use of microbubbles and ultrasound in rat carotid arteries. Furthermore, we assessed whether the cationic liposomal microbubbles could allow long-term enhanced imaging, comparing with SonoVue®. Material and methods Normal rat carotid arteries were imaged after intravenous bolus injections of 0.5 ml/kg of two contrast agents (SonoVue® and the cationic liposomal microbubbles). Forty Sprague-Dawley rats were divided into 5 groups according to ultrasound parameters and were treated with or without microbubbles. All rats were sacrificed after being transfected for 2 days. The level of protein expression was determined by western blot analysis. Results The enhancing time of self-made microbubbles was much longer than that of SonoVue® in rat carotid arteries (p < 0.05). The results of the western blot analysis revealed that the expression of SR-BI DNA in the carotid artery was highest in the SR-BI + US/CLM group (p < 0.05). Conclusions These results suggest that the novel cationic liposomal microbubbles enhance image quality over a longer period than does SonoVue®. Additionally, the combination of ultrasound and this new type of microbubble can act synergistically to increase SR-BI DNA transfection.