[Effect of microvascular pericytes of cochlear stria vascularis on endothelial cell permeability in C57BL/6J mice]

Objective: To study the changes in the permeability of the blood labyrinth barrier of the aging cochlea in mice, and to establish a non-contact co-culture model of endothelial cells (EC) and pericytes (PC) to furtherly investigate the cochlear stria vascularis microvascular pericytes impact on the permeability of endothelial cells. Methods: C57BL/6J mice were divided into two groups, three months old as young group, 12 months old as senile group. Cell experiment was divided into four groups, EC group, EC+PC co-culture group, D-gal+EC group and D-gal+EC+PC co-culture group. Auditory brainstem response (auditory brain response, ABR) was used to detect the auditory function of the two groups of mice. Evans blue staining was applied to detect the permeability of the cochlear blood labyrinth barrier of the two groups of mice. Transmission electron microscopy was used to observe the ultrastructure of blood labyrinth barrier endothelial cells, pericytes and tight junctions in the two groups of mice. Immunohistochemistry was used to detect the expression levels of tight junction proteins in the stria vascularis of the cochlea of the two groups of mice. Transwell chamber was used to detect the permeability of endothelial cells. Western blot and immunofluorescence technology were used to detect the expression level of tight junction protein on endothelial cells. SPSS 20.0 software was used to analyze the data. Results: Compared with the young group, the ABR threshold of the aging group was significantly increased, the latency of wave I was prolonged (t=10.25, P<0.01;t=5.61, P<0.05), the permeability of the cochlear blood labyrinth barrier was increased and the expression of tight junction protein on the vascular stria was decreased (P<0.05). The cochlear ultrastructure showed that the cochlear vascular stria microvascular lumen was deformed, the basement membrane thickened and the tight junction gap between endothelium enlarged. The positive rate of ECs and PCs in primary culture was more than 95%. The cells induced by 15 g/L D-gal were determined to be senescent cells. Compared with EC group, the expression of tight junction protein in endothelial cells of D-gal+EC group decreased（t=7.42，P<0.01；t=13.19，P<0.05）and the permeability increased (t=11.17, P<0.01). In the co-culture group, the expression of tight junction protein between endothelial cells in EC+PC co-culture group and D-gal+EC+PC co-culture group increased and the permeability decreased. Conclusions: In aging mice, the permeability of cochlear blood labyrinth barrier will increase and the level of tight junction protein will decrease; in aging state, cochlear vascular stria microvascular pericytes may affect endothelial cell permeability by regulating the expression of tight junction protein.

Potential Pitfalls in the Analysis and Structural Interpretation of Seismic Data from the Mars InSight Mission

The Seismic Experiment for Interior Structure (SEIS) of the InSight mission to Mars, has been providing direct information on Martian interior structure and dynamics of that planet since it landed. Compared to seismic recordings on Earth, ground motion measurements acquired by SEIS on Mars are made under dramatically different ambient noise conditions, but include idiosyncratic signals that arise from coupling between different InSight sensors and spacecraft components. This work is to synthesize what is known about these signal types, illustrate how they can manifest in waveforms and noise correlations, and present pitfalls in structural interpretations based on standard seismic analysis methods. We show that glitches, a type of prominent transient signal, can produce artifacts in ambient noise correlations. Sustained signals that vary in frequency, such as lander modes which are affected by variations in temperature and wind conditions over the course of the Martian Sol, can also contaminate ambient noise results. Therefore, both types of signals have the potential to bias interpretation in terms of subsurface layering. We illustrate that signal processing in the presence of identified nonseismic signals must be informed by an understanding of the underlying physical processes in order for high fidelity waveforms of ground motion to be extracted. While the origins of most idiosyncratic signals are well understood, the 2.4 Hz resonance remains debated and the literature does not contain an explanation of its fine spectral structure. Even though the selection of idiosyncratic signal types discussed in this paper may not be exhaustive, we provide guidance on best practices for enhancing the robustness of structural interpretations.

Immersive visualisation of intracardiac blood flow in virtual reality on a patient with HLHS

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): NIHR i4i funded 3D Heart project Wellcome/EPSRC Centre for Medical Engineering [WT 203148/Z/16/Z]

onbehalf

3D Heart Project

Background/Introduction: Virtual Reality (VR) for surgical and interventional planning in the treatment of Congenital Heart Disease (CHD) is an emerging field that has the potential to improve planning. Particularly in very complex cases, VR permits enhanced visualisation and more intuitive interaction of volumetric images, compared to traditional flat-screen visualisation tools. Blood flow is severely affected by CHD and, thus, visualisation of blood flow allows direct observation of the cardiac maladaptions for surgical planning. However, blood flow is fundamentally 3D information, and viewing and interacting with it using conventional 2D displays is suboptimal. 

Purpose

To demonstrate feasibility of blood flow visualisation in VR using pressure and velocity obtained from a computational fluid dynamic (CFD) simulation of the right ventricle in a patient with hypoplastic left heart syndrome (HLHS) as a proof of concept.

Methods

 We extend an existing VR volume rendering application to include CFD rendering functionality using the Visualization Toolkit (VTK), an established visualisation library widely used in clinical software for visualising medical imaging data. Our prototype displays the mesh outline of the segmented heart, a slicing plane showing blood pressure on the plane within the heart, and streamlines of blood flow from a spherical source region. Existing user tools were extended to enable interactive positioning, rotation and scaling of the pressure plane and streamline origin, ensuring continuity between volume rendering and CFD interaction and, thus, ease of use. We evaluated if rendering and interaction times were low enough to ensure a comfortable, interactive VR experience. Our performance benchmark is a previous study showing VR is acceptable to clinical users when rendering speed is at least 90 fps.

Results

CFD simulations were successfully rendered, viewed and manipulated in VR, as shown in the Figure. Evaluating performance, we found that visualisation of the mesh and streamlines was at an acceptably high and stable frame rate, over 150fps. User interactions of moving, rotating or scaling the mesh or streamlines origin did not significantly reduce this frame rate. However, rendering the  pressure slicing plane reduced frame rate by an unacceptable degree, to less than 10fps.  

Conclusion

Visualisation of and interaction with CFD simulation data was successfully integrated into an existing VR application. This aids in surgery and intervention planning for defects heavily relying on blood flow simulation, and lays a foundation for a platform for clinicians to test interventions in VR. Pressure plane rendering performance will require significant optimisation, potentially addressed by updating the pressure plane data separately from the main, VR rendering.

Abstract Figure. An example render of CFD simulation

Automatic orientation cues for intuitive immersive interrogation of 3D echocardiographic images in virtual reality using deep learning

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): NIHR i4i funded 3D Heart Project Wellcome / EPSRC Centre for Medical Engineering (WT 203148/Z/16/Z)

onbehalf

3D Heart Project

Background/Introduction:

In echocardiography (echo), image orientation is determined by the position and direction of the transducer during examination, unlike cardiovascular imaging modalities such as CT or MRI. As a result, when echo images are first shown their display orientation has no external anatomical landmarks, thus the user has to identify anatomical landmarks in the regions of interest to understand the orientation. 

Purpose

To display an anatomical model of a standard heart, automatically aligned to an acquired patient’s 3D echo image - assisting image interpretation by quickly orienting the viewer. 

Methods

 

47 echo datasets from 13 pediatric patients with hypoplastic left heart syndrome (HLHS) were annotated by manually indicating the cardiac axes in both ES and ED volumes. We chose a view akin to the standard four chamber view in healthy hearts as the reference view, showing the AV valves, the right atrium, the left atrium and the hypoplastic ventricle. We then trained a deep convolutional neural network (CNN) to predict the rotation required for re-orientation to the reference view. Three data strategies were explored: 1) using 3D images to estimate orientation, 2) using three orthogonal slices only (2.5D approach) and 3) using the central slice only (2D approach). Three different algorithms were investigated: 1) an orientation classifier, 2) an orientation regressor with mean absolute angle error, and 3) an orientation regressor with geodesic loss. The data was split into training, validation and test sets with a 8:1:1 ratio. The training data was augmented by applying random rotations in the range [−10◦, +10◦] and updating labels accordingly. The model with smallest validation error was applied in tandem with the VR visualisation of the echo volumes. 

Results

Experimental results suggest that a 2.5D CNN classifying discrete integer angles performs best in re-orienting volumetric images to the reference view, with a mean absolute angle error on the test set of 9.0 deg (test set error ranges from 10.8 to 25.9 deg. for other algorithms). An HLHS volumetric data (left) is automatically aligned with the cardiac model (right) using our trained network when loaded in VR as shown in Figure 1. The volume and the model are both cropped at the referencing plane.

Conclusion

A deep learning network to align 3D echo images to a reference view was successfully trained and then integrated  into VR to reorient echo volumes to match a standard anatomical view. This work demonstrates the potential of combining artificial intelligence and VR in medical imaging, although further user study is expected to evaluate its clinical impact.

Caption for Abstract Picture

 The VR user interface informs the user of the 3D echo image orientation, automatically aligning it with an anatomical model, here showing the four chamber apical view.

Abstract Figure. Deep learning model integrated into VR

Diagnostic value of combined nucleic acid and antibody detection in suspected COVID-19 cases

OBJECTIVES

Nucleic acid testing is the gold standard method for the diagnosis of coronavirus disease 2019 (COVID-19); however, large numbers of false-negative results have been reported. In this study, nucleic acid detection and antibody detection (IgG and IgM) were combined to improve the testing accuracy of patients with suspected COVID-19.

STUDY DESIGN

The positive rate of nucleic acid detection and antibody detection (IgG and IgM) were compared in suspected COVID-19 patients.

METHODS

A total of 71 patients with suspected COVID-19 were selected to participate in this study, which included a retrospective analysis of clinical features, imaging examination, laboratory biochemical examination and nucleic acid detection and specific antibody (IgM and IgG) detection.

RESULTS

The majority of participants with suspected COVID-19 presented with fever (67.61%) and cough (54.93%), and the imaging results showed multiple small patches and ground-glass opacity in both lungs, with less common infiltration and consolidation opacity (23.94%). Routine blood tests were mostly normal (69.01%), although only a few patients had lymphopenia (4.23%) or leucopenia (12.68%). There was no statistical difference in the double-positive rate between nucleic acid detection (46.48%) and specific antibody (IgG and IgM) detection (42.25%) (P = 0.612), both of which were also poorly consistent with each other (kappa = 0.231). The positive rate of combined nucleic acid detection and antibody detection (63.38%) was significantly increased, compared with that of nucleic acid detection (46.48%) and that of specific antibody (IgG and IgM) detection (42.25%), and the differences were statistically significant (P = 0.043 and P = 0.012, respectively).

CONCLUSIONS

Nucleic acid detection and specific antibody (IgG and IgM) detection had similar positive rates, and their combination could improve the positive rate of COVID-19 detection, which is of great significance for diagnosis and epidemic control.

Activation of the STAT1 Pathway Accelerates Periodontitis in Nos3-/- Mice

Early studies on the etiology and pathogenesis of hypertension have shown that it has a considerable association with inflammation and the immune response as well as periodontitis. Clinical studies have also shown that hypertension can promote the periodontal tissue destruction caused by periodontitis. However, the underlying mechanisms remain unclear. This study aimed to explore the possible mechanisms of how hypertension aggravates periodontitis. Treatment with or without the signal transducer and activator of transcription 1 (STAT1) inhibitor fludarabine was performed in an endothelial nitric oxide synthase gene knockout-related (Nos3^-/-) mouse model with the hypertension phenotype of periodontitis induced by bacteria. Micro-computed tomography, immunohistochemistry, Western blot, quantitative reverse transcription polymerase chain reaction, immunofluorescence, and ELISA were performed. We demonstrated that Nos3^-/--related hypertension increases bone resorption and periodontal destruction in periodontitis lesion areas, which can be inhibited by the STAT1 inhibitor. Experimental data also showed that Nos3^-/- significantly increased macrophage infiltration and proinflammatory cytokine expression in the periodontitis lesion area, which is dependent on the angiotensin II-induced STAT1 pathway. Inhibition of STAT1 in vivo can decrease the expression of proinflammatory cytokines and macrophage infiltration. Furthermore, data in this study showed that Nos3^-/--related hypertension further downregulated the STAT3 anti-inflammatory function and its downstream chemokine expression in a STAT1-dependent manner. By applying RAW 264.7 and L929 cell lines and monocytes isolated from Nos3^-/- mice, we confirmed that activation of the STAT1 pathway inhibits STAT3 and its downstream pathway and promotes inflammatory cytokine expression in vitro. Collectively, our current study demonstrated that STAT1 plays an indispensable role in the Nos3^-/--related hypertension with aggravation of periodontitis, suggesting that STAT1 may be a key target for the treatment of periodontitis with hypertension.

Accuracy of molecular diagnostic tests for drug-resistant tuberculosis detection in China: a systematic review

OBJECTIVE: To evaluate the accuracy of molecular diagnostics for the detection of drug-resistant tuberculosis (TB) in Chinese patients.METHOD: Seven databases were searched for eligible studies that evaluated the accuracy of molecular diagnostics against drug susceptibility testing (DST) for detecting drug resistance. A bivariate random-effects meta-analysis was conducted to pool sensitivity and specificity by the index test and drug resistance type.RESULTS: A total of 159 studies were included. Compared with DST (reference standard), Xpert^® could diagnose rifampicin (RMP) resistant TB accurately, with a pooled sensitivity and pooled specificity of 92% (95%CI 90-94) and 98% (95%CI 97-98), respectively. Line-probe assays (LPAs) also performed well for RMP resistance, with a pooled sensitivity of 91% (95%CI 88-93) and pooled specificity of 98% (95%CI 96-99), but not for isoniazid (INH) or second-line drugs due to lower sensitivity (<80%). The pooled sensitivity of GeneChip^® microarrays for RMP, INH and multidrug resistance was 89% (95%CI 86-91), 79% (95%CI 75-82) and 79% (95%CI 73-84), respectively, and the specificities were all >97%. Similarly, the MeltPro^® TB/STR assay had better sensitivity and specificity for first-line drugs, varying from 87% to 89% and 97% to 98%, respectively, than for second-line drugs.CONCLUSION: The Xpert assay, LPA, GeneChip assay, and MeltPro assay are credible methods with high accuracy for RMP resistance detection, but they may not be appropriate for other anti-tuberculosis drugs due to low sensitivity.

Modulation of inflammatory response and gut microbiota in ankylosing spondylitis mouse model by bioactive peptide IQW

AIMS

Ankylosing spondylitis (AS) is a widespread and chronic inflammatory autoimmune disease of unknown provenance. Naturally occurring peptides and proteins have shown significant promise as modulators of immune responses. Thus, the aims of this study were to assess the protective effects of the bioactive peptide IQW (Ile-Gln-Trp) with respect to inflammatory indicators, gut microbiota and oxidative stress, and to examine the potential mechanisms of these effects.

METHODS AND RESULTS

A mouse model was prepared by four injections of human proteoglycan extract (2 mg) in dimethyldioctadecylammonium solution (2 mg) over an interval of 2 weeks. Enzyme-linked immunosorbent assay results for the markers of oxidative stress and inflammation in the AS mice revealed increased concentrations of malondialdehyde, IL-6, IL-1β and TNF-α, along with decreased concentrations of catalase (CAT), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD). Treatment with IQW was found to decrease the concentrations of IL-6, IL-1β and TNF-α, and increase the concentrations of CAT, GSH-PX and SOD. Moreover the quantification of the microbiota via 16s rRNA sequencing revealed a reduced microbial diversity in the AS mice, while a significantly increased microbial diversity was displayed by those treated with IQW. Whereas, there was a significant reduction in the relative abundance of Bacteroidetes and an increased relative abundance of Verrucomicrobia in AS mice, this was reversed following the IQW treatment.

CONCLUSIONS

The results demonstrated that IQW exerts a beneficial influence in AS by delaying progression of the disease, reducing the arthritic grade of intervertebral joints, altering the concentrations of cytokines and modulating the microbial diversity and composition.

SIGNIFICANCE AND IMPACT OF THE STUDY

Oral IQW treatment might represent a new approach to mitigate the onset and development of AS.

P1417 Acceptability of a virtual reality system for examination of congenital heart disease patients

Funding Acknowledgements

Work supported by the NIHR i4i funded 3D Heart project [II-LA-0716-20001]

Background/Introduction

Virtual Reality (VR) has recently gained great interest for examining 3D images from congenital heart disease (CHD) patients. Currently, 3D printed models of the heart may be used for particularly complex cases. These have been found to be intuitive and to positively impact clinical decision-making. Although positively received, such printed models must be segmented from the image data, generally only CT/MR may be used, the prints are static, and models do not allow for cropping / slicing or easy manipulation. Our VR system is designed to address these issues, as well as providing a simple interface compared to standard software. Building such a VR system, one with intuitive interaction which is clinically useful, requires studying user acceptance and requirements.

Purpose: We evaluate the usability of our VR system

can a prototype VR system be easily learned and used by clinicians unfamiliar with VR.

Method

We tested a VR system which can display 3D echo images and enables the user to interact with them, for instance by translating, rotating and cropping. Our system is tested on a transoesophageal echocardiogram from a patient with aortic valve disease. 13 clinicians evaluated the system including 5 imaging cardiologists, 5 physiologists, 2 surgeons and an interventionist, with their clinical experience ranging from trainee to more than 5 years’ of experience. None had used VR regularly in the past. After a brief training session, they were asked to place three anatomical landmarks and identify a particular cardiac view. They then completed a questionnaire on system ease of learning and image manipulation.

Results: Results are shown in the figure below. Learning to use the system was perceived as easy for all but one participant, who rated it as ‘Somewhat difficult’. However, once trained, all users found the system easy to use. Participants found the interaction, where objects in the scene are picked up using the controller and then track the controller’s motion in a 1:1 way, to be particularly easy to learn and use.

Conclusion

Our VR system was accepted by the vast majority of clinicians, both for ease of learning and use. Intuitiveness and the ability to interact with images in a natural way were highlighted as most useful - suggesting that such a system could become accepted for routine clinical use in the future.

Abstract P1417 Figure. VR system evaluation participant feedbac

P801 A virtual reality tool for measurement of 3D echocardiographic images

Funding Acknowledgements

Work supported by the NIHR i4i funded 3D Heart project [II-LA-0716-20001]

Background/Introduction

Cardiac measurements are clinically important and are invariably required in any clinical imaging software. The advent of Virtual Reality (VR) imaging systems is introducing intuitive and natural ways of visualising and interrogating echo images in a 3D environment. The 3D nature of the VR experience requires purpose-designed measurement tools, which may benefit from better depth perception and easier localisation of 3D landmarks.

Purpose

Comparison of the accuracy of our VR 3D linear measurement system to commercial clinical imaging software, using both multi-plane reformatting (MPR) and volume rendered views.

Method

Each virtual reality measurement was made by selecting two points in 3D, directly in the volume rendering. The participants could edit the measurements until satisfied with their accuracy. 5 expert clinicians carried out 26 measurements each - 6 measurements on a calibration phantom, and 5 anatomically meaningful measurements (for example: aortic valve, left atrium, left ventricle) on 4 datasets. The same measurements were made by all participants using our VR system (volume rendering), Philips" QLAB (MPR) and Tomtec (volume rendering). The frame number and view (for example: long axis) were consistent for each measurement across the 3 packages used.

Results

Preliminary results are shown in the figure below. MPR measurements made on Philips’ QLAB are used as a reference, as this is the most commonly used software for this purpose at our institution. We compare measurements made in Tomtec and VR, both using volume rendering, using Bland-Altman plots. Each measurement data point is the mean of all participants measurements for each dataset/measurement combination. The mean of the measurement differences for the VR system is closer to zero, compared to Tomtec. However, the variation of these differences is larger for the VR system than for Tomtec.

Conclusion

Our preliminary results suggest that the accuracy of line measurements made using volume rendering within a VR system is comparable to measurements made using approved software packages for volume rendering displayed on a 2D screen. This shows promise for more complex interrogation methods.

Abstract P801 Figure. Comparison of Tomtec and VR with QLAB

P1566 Evaluation of haptic feedback for interaction with volumetric image data in virtual reality

Funding Acknowledgements

Work supported by the NIHR i4i funded 3D Heart project [II-LA-0716-20001]

Background

3D printing is used for surgical planning of complex congenital heart disease (CHD) because it provides an intuitive 3D representation of the image data. However, the 3D print is static and it can be costly and time consuming to create. Virtual Reality (VR) is a cheaper alternative that is able to visualise volumetric images in 3D directly from the scanner, both statically (CT and MR) and dynamically (cardiac ultrasound). However, VR visualisation is not as tangible as a 3D print - this is because it lacks the haptic feedback which would make the interactions feel more natural.

Purpose

Evaluate if adding haptic feedback (vibration) to the visualisation of volume image data in VR improves measurement accuracy and user experience.

Method

We evaluated the effect of vibration haptic feedback in our VR system using a synthetic cylinder volume dataset. The cylinder was displayed in two conditions: (1) with no haptic feedback, and (2) with haptic feedback. Ten non-clinical participants volunteered in the evaluation. They were blinded to these two test conditions. The participants were asked to measure the cylinder’s diameter horizontally and vertically, and its length, in each test condition. The measurement results were compared to the ground truth to assess the measurement accuracy. Each participant also completed a questionnaire comparing their experience of the two test conditions during the experiment.

Results

The results show a marginal improvement of measurement accuracy with haptic feedback, compared to no haptics (see Figure a). However, this improvement was not statistically significant. The haptic feedback did improve the participants’ confidence about their performance and increased the ease of use in VR, hence, they preferred the haptics condition to the no haptics condition (see Figure b). Moreover, although 70% of the participants reported relying on the visual cue more than on the haptic cue, 90% found that the haptic cue was helpful for deciding where to place the measurement point. Also, 88.9% of the participants felt more immersed in the VR scene with haptic feedback.

Conclusion

Our evaluation suggests that although haptic feedback may only marginally improve measurement accuracy, participants nevertheless preferred it because it improved confidence in their performance, increased ease of use, and facilitated a more immersive user experience.

Abstract P1566 Figure.

The evolving nature of Bordetella pertussis in Ontario, Canada, 2009-2017: strains with shifting genotypes and pertactin deficiency

This study examined the evolving nature of Bordetella pertussis in Ontario, Canada, by characterizing isolates for their genotypes and expression of pertactin (PRN). From 2009 to 2017, 413 B. pertussis were cultured from pertussis cases at the Public Health Ontario Laboratory. Their genotypes were determined by partial gene sequence analysis of their virulence and (or) vaccine antigens: filamentous haemagglutinin, PRN, fimbriae 3, and pertussis toxin, including the promoter region. Expression of PRN was measured by Western immunoblot. Two predominant genotypes, ST-1 and ST-2, were found throughout the study and were responsible for 47.5% and 46.3% of all case isolates, respectively. The prevalence of ST-1 appeared to fluctuate from 80.3% in 2009 to 20.0% in 2014 and 58.5% in 2017, while the prevalence of ST-2 changed from 18.4% in 2009 to 80.0% in 2014 and 26.2% in 2017. A PRN-deficient strain was first noted in 2011 (16.7%), and its prevalence increased to 70.8% in 2016 but decreased to 46.2% in 2017. More ST-2 (46.6%) than ST-1 (16.8%) strains were associated with PRN deficiency. Newer ST-21 and ST-22 found in 2015-2017 were uniformly PRN deficient. The impact of the evolving nature of B. pertussis on disease epidemiology requires further longitudinal studies.

Endoscopic submucosal multi-tunnel dissection for large early esophageal cancer lesions

OBJECTIVE

To evaluate the safety and efficacy of endoscopic submucosal multi-tunnel dissection (ESMTD) for early esophageal cancer lesions larger than 3 cm in diameter or cumulatively greater than 1/2 lumen size.

METHOD

Early esophageal cancer lesions in 15 patients were detected by endoscopy and endoscopic ultrasonography in our endoscopy center from December 2012 to June 2015. All lesions were successfully resected by ESMTD and diagnosed by pathology, and therapeutic efficiency and safety were followed after surgery.

RESULTS

All 15 of the early esophageal cancer lesions were resected by ESMTD. The pathological results showed 9 moderately differentiated and 6 highly differentiated squamous cell carcinomas. En bloc resection was achieved in 13 lesions, with negative lateral and basal margins on pathology, whereas the other 2 required additional surgery. The average diameter of the resected lesions was 4.2±0.9 cm. The mean procedure time was 94.7±52.9 min. Esophageal stenosis was observed in 7 patients for whom esophageal water balloon dilatation was performed. No residual or recurrent lesion was found during the 6-36-month follow-up period.

CONCLUSION

ESMTD is a safe and efficient technique for treating large early esophageal cancer lesions. Grasping the key techniques of this procedure can reduce operating difficulty and shorten the operating time.

The role of MIR-186 and ZNF545 in inhibiting the proliferation of multiple myeloma cells

This study aimed to investigate the mechanism underlying the inhibitory effect of tumor suppressor gene miR-186 and zinc finger protein 545 (ZNF545) on the proliferation of multiple myeloma (MM) cells. CD138 magnetic beads were used to isolate different types of myeloma cell lines (KM3, U266, RPMI-8226, and H929), which were then infected by lentivirus carrying the miR-186 gene. Using uninfected myeloma cells as the control, MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide] assay was performed to calculate the rate of cell proliferation at different time points. In addition, the correlation between the expression of Jagged 1 and miR-186 was analyzed by real-time Polymerase Chain Reaction (PCR). Furthermore, the effect of 5-Aza-2-deoxycytidine and acetylase inhibitor Trichomycin A (TSA) on the expression of ZNF545 and proliferation/apoptosis of MM cells was investigated using Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western blotting (WB), MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] cell proliferation assay, and Annexin V-FITC/PI staining. Compared with the control group, the proliferation of miR-186-overexpressing U266 and RPMI-8226 cells was significantly decreased. In cell cloning experiments, miR-186 decreased the number of U266 and RPMI-8226 clones while reducing the protein expression of Jagged 1. The expression level of ZNF545 in myeloma patients was also reduced to some extent. ZNF545 protein also promoted the apoptosis of myeloma cells. By inhibiting the proliferation of myeloma cells, miR-186 gene and ZNF protein may be used as tumor suppressors in the treatment of myeloma.

[Role and mechanism of the regulation of nuclear factor-κB by heparin binding-epidermal growth factor-like growth factor in the induction of paclitaxel resistance of ovarian cancer]

Objective: To investigate the role and mechanism of the regulation of nuclear factor-κB (NF-κB) by heparin binding-epidermal growth factor-like growth factor (HB-EGF) in paclitaxel resistance of ovarian cancer in vitro and in vivo. Methods: (1) The detection of NF-κB expression: parental (A2780) and paclitaxel-resistant (A2780/Taxol) ovarian carcinoma cells were divided into four groups, named A2780 group, A2780+cross-reacting material 197 (CRM197, HB-EGF inhibitor) group, A2780/Taxol group and A2780/Taxol+CRM197 group. Among four groups, the expression level HB-EGF and epidermal growth factor receptor (EGFR) were examined by immunofluorescence double staining on confocal microscopy. Western blot was used to detect the expression level of NF-κB. In vivo, A2780 and A2780/Taxol cells were injected intraperitoneally to nude mouse to determine the expression level of NF-κB of the tumors from these four groups by immunohistochemistry method. (2) The detection on the function of NF-κB: A2780/Taxol cells were divided into four groups, named transfected with empty vector+saline group, NF-κB small interference RNA (siRNA)+saline group, empty vector+CRM197 group and NF-κB siRNA+CRM197 group respectively. Among four groups, the 50% inhibitory concentrations (IC(50)) of A2780/Taxol cells to paclitaxel, the expression level of plasma membrane glycoprotein (P-gp) and the effect of intracellular rhodomine123 (Rh123) accumulation were detected. Results: (1) The detection of NF-κB expression: the expression scores of HB-EGF protein among four groups were 5.6±1.3, 2.1±1.2, 11.7±3.5 and 6.2±1.4; the expression scores of EGFR protein were 5.1±1.6, 2.8±0.6, 10.4±3.1 and 5.6±1.9, respectively. The expression levels of NF-κB protein in the cells of the group named A2780, A2780+CRM197, A2780/Taxol and A2780/Taxol+CRM197 group were 1.89±0.23, 0.74±0.12, 3.45±0.16 and 1.31±0.08, respectively; the expression scores of NF-κB protein in the tissue tumors from four groups were 3.3±1.1, 1.4±0.4, 8.7±2.3 and 3.6±1.2, respectively. The expression level of HB-EGF, EGFR and NF-κB protein between A2780 and A2780/Taxol groups in vivo and in vitro were higher than these in A2780+CRM197 and A2780/Taxol+CRM197 group, while the expression level of HB-EGF, EGFR and NF-κB protein in A2780 group were lower than those in A2780/Taxol groups in vivo and in vitro (P<0.05). (2) The examination of NF-κB function: the IC(50) of A2780/Taxol cells to paclitaxel in groups transfected with empty vector+saline, NF-κB siRNA+saline, empty vector+CRM197 and NF-κB siRNA+CRM197 group were respectively (39.4±0.8), (7.6±0.6), (6.7±0.5) and (4.2±0.4) μmol/L, while the expression levels of P-gp protein among four groups were respectively 3.11±0.23,1.45±0.16, 1.73±0.21 and 0.68±0.14, the cellular Rh123 accumulation among four groups were respectively 110±15, 246±19, 231±22 and 296±24. The expression levels of IC(50) and P-gp protein in groups transfected with NF-κB siRNA+saline, empty vector+CRM197 and NF-κB siRNA+CRM197 group were significantly higher than those in group transfected with empty vector+saline group (P<0.01), while the cellular Rh123 accumulation among three groups were significantly lower than that in group transfected with empty vector+saline (P<0.01). Conclusions: The expression of NF-κB may contributes to the paclitaxel resistance to ovarian cancer. HB-EGF may induce the paclitaxel resistance of ovarian cancer by the regulation of EGFR/NF-κB/P-gp pathway.