A New Framework for Performing Cardiac Strain Analysis from Cine MRI Imaging in Mice

Cardiac magnetic resonance (MR) imaging is one of the most rigorous form of imaging to assess cardiac function in vivo. Strain analysis allows comprehensive assessment of diastolic myocardial function, which is not indicated by measuring systolic functional parameters using with a normal cine imaging module. Due to the small heart size in mice, it is not possible to perform proper tagged imaging to assess strain. Here, we developed a novel deep learning approach for automated quantification of strain from cardiac cine MR images. Our framework starts by an accurate localization of the LV blood pool center-point using a fully convolutional neural network (FCN) architecture. Then, a region of interest (ROI) that contains the LV is extracted from all heart sections. The extracted ROIs are used for the segmentation of the LV cavity and myocardium via a novel FCN architecture. For strain analysis, we developed a Laplace-based approach to track the LV wall points by solving the Laplace equation between the LV contours of each two successive image frames over the cardiac cycle. Following tracking, the strain estimation is performed using the Lagrangian-based approach. This new automated system for strain analysis was validated by comparing the outcome of these analysis with the tagged MR images from the same mice. There were no significant differences between the strain data obtained from our algorithm using cine compared to tagged MR imaging. Furthermore, we demonstrated that our new algorithm can determine the strain differences between normal and diseased hearts.

3D porous framework of ZnO nanoparticles assembled from double carbon shells consisting of hard and soft carbon networks for high performance lithium ion batteries

Low electronic conductivity and large volume variation result in inferior lithium storage performance of ZnO. To overcome these shortcomings of ZnO, herein ZnO nanoparticles are encapsulated in resorcinol-formaldehyde resin-derived hard carbon and then further assembled into a 3-dimensional mesoporous framework structure using a polyvinyl pyrrolidone-derived soft carbon network. The synthesis methods include the polymerization of resorcinol-formaldehyde resin and a polyvinyl pyrrolidone-boiling method. ZnO@dual carbon has af large specific surface area (153.7 m² g^-1) and high porosity. It exhibits excellent cycling performance and high rate capability. After 350 cycles at 500 mA g^-1, the ZnO@dual carbon still delivers a discharge capacity of 701 mAh g^-1 while the actual discharge capacity of ZnO reaches 950.9 mAh g^-1. At 2 A g^-1, ZnO@dual carbon delivers the average discharge capacity of 469.6 mAh g^-1. The electrochemical performance of ZnO@dual carbon is remarkably superior to those of ZnO@single carbon, pure carbon and pure ZnO nanoparticles, demonstrating the superiority of the dual carbon-assembly structure. This composite structure greatly improves the structural stability of ZnO, enhances its electron conductivity and overall electron transport capacity; which facilitates electrolyte penetration and Li ion diffusion, leading to improved cycling stability and good rate capability.

A novel, rapid and simple method for detecting brucellosis based on rapid vertical flow technology

AIMS

To prevent the spread of brucellosis, a simple and rapid vertical flow technology (RVFT) for the detection of antibodies targeting brucellosis was developed.

METHODS AND RESULTS

In this study, Brucella sp. lipopolysaccharide was purified and used to detect brucellosis antibodies. Sheep IgG was used as a negative control. Colloidal gold-labeled recombinant staphylococcus aureus protein A was sprayed on a fibreglass membrane to prepare immunogold pads. Rapid vertical flow technology was used to detect Brucella in 1668 Sheep, 2743 bovine, 674 red deer and 420 human samples. The results indicated that the accuracy of this assay can reach 98%.

CONCLUSIONS

The established RVFT uses a single multifunctional buffer that can be used to detect antibodies in serum, plasma, whole blood and other biological samples while preserving the advantages of lateral-flow immunoassays.

SIGNIFICANCE AND IMPACT OF THE STUDY

This technology would be of great use in primary medical units and veterinary stations, and it is of great significance for the control of epidemic diseases.

[Clinical study of apatinib combined with chemotherapy for advanced non-small cell lung cancer with negative driving genes]

Objective: To evaluate the efficacy and safety of apatinib combined with chemotherapy in the first-line treatment of advanced non-small cell lung cancer (NSCLC) with negative driving genes. Methods: From January 2016 to March 2018, 62 advanced NSCLC patients with negative driving genes diagnosed at Xuzhou Cancer Hospital were randomly divided into study group (30 cases) and control group (32 cases), respectively. The patients in the study group were treated with standard first-line chemotherapy combined with apatinib, while those in control group were treated with chemotherapy alone. Results: The disease control rate (DCR) and objective remission rate (ORR) in the study group were 60.0% and 16.7%, respectively, higher than 46.9% and 9.3% in the control group, but without statistical difference (P>0.05). The median progression-free survival (PFS) of study group and control group were 6.4 months and 4.9 months, respectively (P=0.004), and the median overall survival (OS) were 11.3 months and 9.2 months, respectively (P=0.006). Multivariate survival analysis indicated that treatment regimen (P=0.001) was the independent prognostic factor of PFS, and PS score (P=0.002), clinical stage (P=0.02) and treatment regimen (P<0.001) were the independent prognostic factors of OS. After treatment, the incidence of hypertension and hand-foot syndrome in the study group were 46.7% and 53.3%, respectively, significantly higher than 3.3% and 0 in the control group, respectively (P<0.05). The incidence of grade 3-4 adverse drug reactions (ADRs) in the study group was 26.7% (8/30), mainly including hypertension, hand-foot syndrome and bone marrow suppression. The incidence of grade 3-4 ADRs in the control group was 15.6% (5/32), all of which were bone marrow suppression, without significant difference (P=0.286). There was no difference in serum levels of VEGF and CEA between the two groups before treatment. After treatment, the serum level of VEGF in the study group was (169.3±10.1) pg/ml, lower than (211.8±16.7) pg/ml of the control group (P<0.05). Conclusion: Apatinib combined with first-line chemotherapy for advanced NSCLC patients with negative driving genes is safe and beneficial for survival. This therapeutic strategy can significantly prolong the PFS and OS, and further improvement and application can be considered as a choice in the clinical treatment.

Metformin relieves acute respiratory distress syndrome by reducing miR-138 expression

OBJECTIVE

To investigate whether metformin can relieve acute respiratory distress syndrome (ARDS). Its potential mechanism was also explored.

MATERIALS AND METHODS

The ARDS model was established by injecting LPS into mice that received metformin in advance and the mice in the control group. Pulmonary edema was detected by W/D ratios (wet-to-dry weight ratios), and the vascular exudation was reflected by the protein content and cell number of alveolar lavage fluid. Meanwhile, MPO (myeloperoxidase) activity assay was performed to analyze the neutrophil aggregation. The expression of inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-17, were detected by enzyme-linked immunosorbent assay (ELISA). This series of experiments reflected the alleviation effect of metformin on ARDS. To further study the mechanism, we cultured alveolar macrophages (NR8383) in vitro and treated them with LPS and metformin. Western blot was used to detect the phosphorylation levels of p38, ERK, NF-kB, and SIRT1 expression level. Bioinformatics method was then used to predict the binding of miR-138 to SIRT1. The mRNA and protein expression of SIRT1 was detected in NR8383 cells transfected with miR-138 inhibitor. The dual luciferase gene reporter assay was used to detect the relative luciferase activities of miR-138 and SIRT1.

RESULTS

Pulmonary edema, vascular exudation, and neutrophil accumulation were observed in the ARDS model mice, and the levels of inflammatory cytokines including TNF-α, IL-1b, IL-6, and IL-17 were significantly increased. After metformin treatment, these pulmonic damage indicators were found to be partially reversed. At the same time, metformin could significantly reduce LPS-induced death. After NR8383 was treated with metformin and LPS, the expression of SIRT1 was higher than that of LPS treatment alone, but the expression of p-p38, p-ERK, and p-NF-κB was significantly decreased. After the addition of metformin in NR8383 after LPS treatment, the expression level of miR-138-5p was significantly decreased, and miR-138-5p was confirmed to target SIRT1 and regulate its expression.

CONCLUSIONS

Metformin could reduce LPS-induced pulmonic injury and increase expression of inflammatory factors. A possible mechanism might be that metformin-induced low expression of mir-138-5p could target SIRT1 to increase its expression and suppress the MAPK pathway, thus alleviating ARDS.

Research and analysis of 74 bloodstream infection cases of Acinetobacter baumannii and drug resistance

OBJECTIVE

We aimed at investigating the clinical and bacteriological features and drug resistance of bloodstream infection of Acinetobacter baumannii, so as to provide new evidence for treatment of bloodstream infection of Acinetobacter baumannii.

PATIENTS AND METHODS

Statistical analysis was carried out for the clinical and bacteriological features and drug sensitivity of 74 bloodstream infection cases of Acinetobacter baumannii who were admitted to this hospital between July 2016 and June 2017.

RESULTS

Among 74 patients, about 72.0% of them were admitted to the ICU and Respiratory Department; the average age of these patients was 63 years old. Among 74 patients, 62 patients stayed in the hospital for over 2 weeks (83.8%), and 35 for over 1 month (47.3%); 72.0% of patients experienced intrusive operation, in which 28.0% of patients dead. The experiment of drug sensitivity showed that tigecycline had the highest sensitivity (100%), sequentially followed by amikacin (over 90.0%) and other anti-bacterial drugs (less than 40.0%). Pan-drug resistance was identified in 42 patients, accounting for 56.8%. Comparison between the pan-drug resistant and non-pan-drug resistant patients showed that in the first two weeks before the positive blood culture, there were statistically significant differences in administration of carbapenem antibiotics and intrusive operation (p<0.05). Among the patients, the lowest resistance to carbapenem antibiotics was 8.16%, while the rate of resistance to other 12 antibiotics was more than 40.00%. Multiple-resistant strain mainly originated from the ICU and the burn center.

CONCLUSIONS

In patients with bloodstream infection of Acinetobacter baumannii, the pan-drug resistant strains account for a vast majority with a high mortality rate. Age, intrusive operation and length of stay in hospital longer than 2 weeks are the common susceptible factors, while the administration of carbapenem antibiotics and intrusive operations might be the high-risk factors leading to pan-drug resistant cases.

Simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) imaging for cervical artery dissections

AIM

To evaluate the feasibility of high-resolution magnetic resonance imaging (MRI) with a simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) sequence in identifying cervical artery dissections (CeAD).

MATERIALS AND METHODS

Fifty-three patients with suspected CeAD underwent the SNAP sequence (including non-contrast magnetic resonance angiography [MRA] and heavy T1-weighting vessel wall images simultaneously in a single scan) and conventional MRI sequences (including three-dimensional [3D] time-of-flight MRA and T1-weighted black-blood imaging [T1W BB]) and cervical vascular ultrasound (CVUS). In diagnosis of CeAD, the diagnostic sensitivity and specificity of SNAP, and the diagnostic coherence between SNAP and conventional sequences and between SNAP and CVUS was analysed. At follow-up, the absolute signal (AS) and signal index (SI) of the intramural haematoma (IMH) between vessel wall images on SNAP and T1W-BB images were compared. The image quality of SNAP was analysed by comparing the signal-to-noise ratio (SNR) between vessel wall images from the SNAP and T1W-BB sequences.

RESULTS

The SNAP sequence was found to provide good performance in the diagnosis of CeAD (sensitivity 72.2%, specificity 98.2%); good agreement was found between SNAP and conventional sequences (Cohen's κ=0.76, p<0.05); and excellent agreement was found between SNAP and CVUS (Cohen's κ=0.83, p<0.05). There was no significant difference between AS or SI of the IMH of the vessel wall images within the SNAP and T1W-BB sequences during the review. The SNAP sequence had higher SNR of the IMH compared to T1W-BB, T2W-BB, proton-density-weighted volume isotropic turbo-spin-echo acquisition imaging (PD-VISTA) sequences (p<0.05).

CONCLUSION

The SNAP sequence holds the potential to be preferred choice for screening of patients with a high suspicion of CeAD and for the follow-up of IMH after treatment.

Prognostic factors for treatment success in patients with multidrug-resistant tuberculosis in China

OBJECTIVE

To examine the clinical outcomes and associated prognostic factors among patients with multidrug-resistant tuberculosis (MDR-TB) in China.

METHODS

This retrospective study involved 243 patients with MDR-TB. All patients received standard regimens containing para-amino salicylic acid (PAS) and/or cycloserine (CS). The demographic, social and clinical characteristics of patients were recorded and the patients were followed up for 24 months.

RESULTS

Treatment success was closely associated with young age, non-farming occupations, shorter history or smoking, normal urine results, initial MDR-TB treatment regimen, increased haemoglobin, direct bilirubin, uric acid and thyroid stimulating hormone (TSH) levels, and lower white blood cell, neutrophil and blood platelet counts (all P < 0.05). On multivariable analysis, increased haemoglobin (hazard ratio [HR] 1.019, 95%CI 1.007-1.032, P = 0.002) and TSH levels (HR 1.002, 95%CI 1.006-1.039, P = 0.008), normal urine results (HR 1.541, 95%CI 1.008-2.358, P = 0.046) and initial MDR-TB treatment regimen (HR 2.238, 95%CI 1.090-4.597, P = 0.028) were prognostic factors for treatment success in MDR-TB.

CONCLUSIONS

Higher haemoglobin and TSH levels, normal urine results and initial MDR-TB treatment regimen might predict successful treatment of MDR-TB.

Paeonol ameliorates lipopolysaccharides-induced acute lung injury by regulating TLR4/MyD88/ NF-κB signaling pathway

Paeonol has been found to hold analgesic, antipyretic and anti-allergic activities. Here, we investigated the protective effect of paeonol on acute lung injury (ALI) induced by lipopolysaccharides (LPS) and explored the underlying mechanisms on TLR4/MyD88/NF-κB signaling pathway. C57BL/6 mice were randomly divided into control (normal saline, NS, 0.2 mL/d), LPS (NS, 0.2 mL/d), LPS + dexamethasone (DXMS) (5 mg/kg/d), LPS + paeonol (50, 25, 12.5 mg/kg/d) groups. The results of the lung tissue scores scale and HE staining showed that paeonol could attenuate the infiltration of inflammatory cells and the thickening of alveolar wall significantly. The result of W/D ratio showed that paeonol could also prevent pulmonary edema, as well as inhibit significantly the levels of TNF-α, IL-1β and IL-6 in serum and proteins expression and mRNA. In addition, paeonol can also downregulate the expression or phosphorylation of TLR4, MyD88 and NF-κB. In general, our findings showed that the protective effect of paeonol on LPS-induced ALI by regulating TLR4/MyD88/NF-κB signaling pathway. This study provides evidence for the application of paeonol in treating ALI.

Intracellular manipulation and measurement with multipole magnetic tweezers

The capability to directly interrogate intracellular structures inside a single cell for measurement and manipulation is important for understanding subcellular and suborganelle activities, diagnosing diseases, and developing new therapeutic approaches. Compared with measurements of single cells, physical measurement and manipulation of subcellular structures and organelles remain underexplored. To improve intracellular physical measurement and manipulation, we have developed a multipole magnetic tweezers system for micromanipulation involving submicrometer position control and piconewton force control of a submicrometer magnetic bead inside a single cell for measurement in different locations (spatial) and different time points (temporal). The bead was three-dimensionally positioned in the cell using a generalized predictive controller that addresses the control challenge caused by the low bandwidth of visual feedback from high-resolution confocal imaging. The average positioning error was quantified to be 0.4 μm, slightly larger than the Brownian motion–imposed constraint (0.31 μm). The system is also capable of applying a force up to 60 pN with a resolution of 4 pN for a period of time longer than 30 min. The measurement results revealed that significantly higher stiffness exists in the nucleus’ major axis than in the minor axis. This stiffness polarity is likely attributed to the aligned actin filament. We also showed that the nucleus stiffens upon the application of an intracellularly applied force, which can be attributed to the response of structural protein lamin A/C and the intracellular stress fiber actin filaments.

Erythropoietin Ameliorates Lung Injury by Accelerating Pulmonary Endothelium Cell Proliferation via Janus Kinase-Signal Transducer and Activator of Transcription 3 Pathway After Kidney Ischemia and Reperfusion Injury

BACKGROUND/AIMS

Kidney ischemia and reperfusion injury could cause microvascular barrier dysfunction, lung inflammatory cascades activation, and programmed cell death of pulmonary endothelium, leading to acute lung injury. Our study aimed at determining whether erythropoietin (EPO) can ameliorate lung dysfunction following renal ischemia and reperfusion (IR) injury and explored the underlying mechanisms.

METHODS

In vivo, C57BL/6 mice received EPO (6000 U/kg) before right renal vascular pedicles clamping for 30 minutes, followed by 24 hours of reperfusion. The lung histopathologic changes and inflammatory cytokines expression were assessed. In vitro, cultured human umbilical vein endothelial cells were treated with EPO, and apoptosis rate, proliferation capacity, and phosphorylation status of the Janus kinase-signal transducer and activator of transcription 3 (Jak-STAT3) pathway were measured respectively in the presence or absence of lipopolysaccharide stimulation.

RESULTS

In vivo, EPO remarkably attenuated pulmonary interstitial and alveolar epithelial edema caused by renal IR injury. In vitro, the proliferation capacity of human umbilical vein endothelial cells was significantly increased under EPO stimulation, which correlated with changes in Jak-STAT3 signaling.

CONCLUSION

Our data indicated that EPO is able to ameliorate acute lung tissue damage induced by renal IR, and at least in part, via the Jak-STAT3 pathway.

[Study on genetic structure differences and adjustment strategies in different areas of China]

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.