[Efficacy of thymectomy in patients with non-thymoma myasthenia gravis]

Objective: To compare the efficacy between thymectomy plus prednisone and prednisone alone in patients with non-thymoma myasthenia gravis (MG). Methods: Thirty generalized MG patients without thymoma who underwent thymectomy were collected as the operation group, and thirty-nine patients without thymectomy who were treated with prednisone alone were matched as the control group. The start point was the enrollment time and the endpoint event was the "clinical remission" (including complete stabilization remission, drug remission, and poor performance). The survival curve was used to analyze the difference of endpoint event time between the two groups. Besides, a 12-month follow-up study was conducted to compare relevant clinical indicators between the two groups. Results: There was no significant difference in the occurrence time of endpoint events between the two groups (P=0.614). After 6-month follow-up, no significant differences were found in clinical remission rate, the dosage of pyridostigmine bromide and prednisone, the peak dosage of prednisone, the use of other immunosuppressive medications and the rate of hospitalization for exacerbation of disease between the two groups (all P>0.05). After 12-month follow-up, the dosage of prednisone and pyridostigmine in the operation group was significantly lower than that in the control group (5(0,10)mg/d vs 7.5(5,10)mg/d and 30(0,105)mg/d vs 90(15,180)mg/d; P=0.038, 0.032). Conclusion: In patients with mild to moderate non-thymoma generalized MG, thymectomy does not achieve faster remission, but it does reduce the long-term dosage of prednisone and bromopyrazine.

PRL3 enhances T-cell acute lymphoblastic leukemia growth through suppressing T-cell signaling pathways and apoptosis

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes and is largely driven by the NOTCH/MYC pathway. Yet, additional oncogenic drivers are required for transformation. Here, we identify protein tyrosine phosphatase type 4 A3 (PRL3) as a collaborating oncogenic driver in T-ALL. PRL3 is expressed in a large fraction of primary human T-ALLs and is commonly co-amplified with MYC. PRL3 also synergized with MYC to initiate early-onset ALL in transgenic zebrafish and was required for human T-ALL growth and maintenance. Mass spectrometry phosphoproteomic analysis and mechanistic studies uncovered that PRL3 suppresses downstream T cell phosphorylation signaling pathways, including those modulated by VAV1, and subsequently suppresses apoptosis in leukemia cells. Taken together, our studies have identified new roles for PRL3 as a collaborating oncogenic driver in human T-ALL and suggest that therapeutic targeting of the PRL3 phosphatase will likely be a useful treatment strategy for T-ALL.

Association study of SNCA gene polymorphisms with schizophrenia in a Chinese North Han population

OBJECTIVE

Previous studies suggested that the alpha-synapse protein (SNCA) gene and its coding product α-synuclein (α-Syn) may play a role in the pathogenesis of neurodegenerative diseases. The mutation of SNCA can influence the formation of nerve fibers and the function of dopaminergic neurons, and that may be related to addictive behavior, such as alcohol dependence. SNCA may overlap with the pathogenesis of schizophrenia and Parkinson's disease or alcohol dependence associated with the dopamine pathway. The aim was to determine the association between three SNCA SNPs (rs3822086C/T, rs11931074G/T, and rs356219A/G) and schizophrenia in a Chinese North Han population.

PATIENTS AND METHODS

A total of 878 subjects, with or without schizophrenia, were included in our study. DNA purification, Polymerase Chain Reaction (PCR) amplification, and subsequent restriction fragment length polymorphism (RFLP) analysis were manipulated to determine genotypes.

RESULTS

Between the schizophrenia group and healthy group, neither the genotype nor allele frequencies of rs3822086C/T, rs11931074G/T, or rs356219A/G differed significantly in either the total sample or the subgroups. In the haplotype analysis, the ATT and GTT haplotype frequencies differed significantly between the patients and controls in the total sample (χ2=6.052, p=0.0139; χ2=4.508, p=0.0337). In the female subgroup, the ATT haplotype frequency differed significantly between the patients and controls (χ2=4.219, p=0.04).

CONCLUSIONS

There was no association between SNCA polymorphisms and schizophrenia in the North Han Chinese population, and the ATT haplotype may be a susceptibility factor for schizophrenia.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Rapid and visual detection of 2019 novel coronavirus (SARS-CoV-2) by a reverse transcription loop-mediated isothermal amplification assay

OBJECTIVE

To evaluate a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and compare it with RT-PCR.

METHODS

We designed primers specific to the orf1ab and S genes of SARS-CoV-2. Total viral RNA was extracted using the QIAamp Viral RNA Mini Kit. We optimized the RT-LAMP assay, and evaluated it for its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation.

RESULTS

The primer sets orf1ab-4 and S-123 amplified the genes in the shortest times, the mean (±SD) times were 18 ± 1.32 min and 20 ± 1.80 min, respectively, and 63°C was the optimum reaction temperature. The sensitivities were 2 × 10¹ copies and 2 × 10² copies per reaction with primer sets orf1ab-4 and S-123, respectively. This assay showed no cross-reactivity with 60 other respiratory pathogens. To describe the availability of this method in clinical diagnosis, we collected 130 specimens from patients with clinically suspected SARS-CoV-2 infection. Among them, 58 were confirmed to be positive and 72 were negative by RT-LAMP. The sensitivity was 100% (95% CI 92.3%-100%), specificity 100% (95% CI 93.7%-100%). This assay detected SARS-CoV-2 in a mean (±SD) time of 26.28 ± 4.48 min and the results can be identified with visual observation.

CONCLUSION

These results demonstrate that we developed a rapid, simple, specific and sensitive RT-LAMP assay for SARS-CoV-2 detection among clinical samples. It will be a powerful tool for SARS-CoV-2 identification, and for monitoring suspected patients, close contacts and high-risk groups.

CTXA hip: the effect of partial volume correction on volumetric bone mineral density data for cortical and trabecular bone

This study compares the results of computed tomography X-ray absorptiometry (CTXA) hip volumetric BMD (vBMD) analyses of cortical and trabecular bone with and without partial volume correction. For cortical bone in some circumstances, corrected cortical volumes were negative and corrected vBMD was very high. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

PURPOSE

Previous studies have reported concerns about the reliability of CTXA hip cortical vBMD measurements generated using partial volume (PV) correction (the "default" analysis, with cortical PV correction). To date, no studies have examined the results of the alternative ("new") analysis (with trabecular PV correction). This study presents in vivo and phantom data comparing the corrected and uncorrected data for cortical and trabecular bone respectively.

METHODS

We used the commercial QCTPro CTXA software to analyze CT scans of 129 elderly Chinese men and women and an anthropomorphic European Proximal Femur phantom (EPFP) and accessed data for two alternative scan analyses using the database dump utility. The CTXA software gives the user two methods of performing the PV correction: (1) a default analysis in which only cortical bone results are corrected; (2) a new analysis in which only trabecular bone results are corrected. Both methods are based on a numerical recalculation of vBMD values without any change in volume of interest (VOI) placement.

RESULT

In vivo, the results of the two analyses for integral bone were the same while cortical and trabecular results were different. PV correction of cortical bone led to a decrease of cortical volume for all four VOIs: total hip (TH), femoral neck (FN), trochanter (TR), and intertrochanter (IT) volumes were reduced on average by 7.8 cm³, 0.9 cm³, 2.5 cm³, and 4.3 cm³ respectively. For TR, where cortex was thinnest, average corrected cortical volume was negative (- 0.4± 1.3 cm³). Corrected cortical vBMD values were much larger than uncorrected ones for TH, FN, and IT. Scatter plots of corrected cortical vBMD against cortical bone thickness showed that elevated results correlated with thinner cortices. When trabecular bone was corrected for the PV effect, trabecular volumes of TH, FN, TR, and IT were reduced on average by 7.9 cm³, 0.8 cm³, 2.6 cm³, and 4.4 cm³ respectively, while vBMD measurements were increased correspondingly. The trabecular volume and vBMD measurements of the two datasets both had highly positive correlations. For the EPFP, the PV-corrected FN data deviated from the nominal phantom value, but was closer for the TR and IT VOIs. Both corrected and uncorrected data overestimated trabecular vBMD, with the corrected results showing greater deviation from nominal values.

CONCLUSION

The default and new CTXA analyses for volumetric data generate different results, both for cortical and trabecular bone. For cortical bone, the uncorrected results are subject to partial volume effects but the correction method of the default analysis overcorrects the effect leading to in part unreasonable results for cortical bone volume and BMD. For trabecular bone, the correction effects are smaller. CTXA volumetric data should be interpreted with caution.

Anastomosis for distal gastrectomy in Chinese patients: uncut roux-Y or roux-Y?

Background

An appropriate method of anastomosis is crucial for gastric cancer patients who require gastrojejunal anastomosis. Surgeons have proposed different types of modified gastrojejunostomies in the last two decades. We focused on two types of standard anastomosis, i.e., Uncut Roux-Y and Roux-Y gastrojejunostomies, and compared the differences in immediate postoperative complications between the two types.

Methods

This is a retrospective study on 236 gastric cancer patients who underwent curative distal gastrectomy with gastrojejunal Roux-Y or Uncut Roux-Y anastomosis for six consecutive years. Immediate postoperative complications were compared between the two groups. The authors discussed the causes of the significant complications and their management.

Results

There was no difference in demographics between the two groups (92 Roux-y Versus 144 Uncut Roux-y). The overall complication rate was 20.8% with 1.4% anastomotic leakage in the Uncut Roux-Y group versus 33.7% with 7.6% anastomotic failures in the Roux-Y group (p < 0.05). More abdominal infections occurred in the Roux-Y anastomosis group compared with the Uncut Roux-Y anastomosis group (p < 0.05). Duration of postoperative stay was significantly longer in patients with Roux-y anastomosis group (p < 0.05).

Conclusions

Considering the surgical simplicity and postoperative complications, the Uncut Roux-Y is a better choice for anastomosis in patients with gastric cancer undergoing gastrojejunostomy. A well-designed large cohort in a multi-centre randomized controlled trial is necessary to support these findings and compare other aspects.

The Safety and Immunogenicity of GTU®MultiHIV DNA Vaccine Delivered by Transcutaneous and Intramuscular Injection With or Without Electroporation in HIV-1 Positive Subjects on Suppressive ART

Previous studies have shown targeting different tissues via the transcutaneous (TC) and intramuscular injection (IM) with or without electroporation (EP) has the potential to trigger immune responses to DNA vaccination. The CUTHIVTHER 001 Phase I/II randomized controlled clinical trial was designed to determine whether the mode of DNA vaccination delivery (TC+IM or EP+IM) could influence the quality and function of induced cellular immune responses compared to placebo, in an HIV positive clade B cohort on antiretroviral therapy (ART). The GTU^®MultiHIV B DNA vaccine DNA vaccine encoded a MultiHIV B clade fusion protein to target the cellular response. Overall the vaccine and regimens were safe and well-tolerated. There were robust pre-vaccination IFN-γ responses with no measurable change following vaccination compared to placebo. However, modest intracellular cytokine staining (ICS) responses were seen in the TC+IM group. A high proportion of individuals demonstrated potent viral inhibition at baseline that was not improved by vaccination. These results show that HIV positive subjects with nadir CD4+ counts ≥250 on suppressive ART display potent levels of cellular immunity and viral inhibition, and that DNA vaccination alone is insufficient to improve such responses. These data suggest that more potent prime-boost vaccination strategies are likely needed to improve pre-existing responses in similar HIV-1 cohorts (This study has been registered at http://ClinicalTrials.gov under registration no. NCT02457689).

Bone mineral density gains with a second 12-month course of romosozumab therapy following placebo or denosumab

Romosozumab is a therapy that stimulates bone formation and reduces bone resorption. In this study of postmenopausal women with low BMD, a second course of romosozumab following a period off treatment or on denosumab increased or maintained BMD, respectively, and was well tolerated, providing insight into treatment sequence options.

INTRODUCTION

In patients with high fracture risk, therapies that stimulate bone formation provide rapid BMD gains; currently available agents, parathyroid hormone receptor agonists, are limited to a 2-year lifetime exposure and generally used for a single treatment course. However, for long-term osteoporosis management, a second treatment course may be appropriate. Romosozumab, a therapy with the dual effect of increasing bone formation and decreasing bone resorption, reduces fracture risk within 12 months. Here, we report efficacy and safety of a second romosozumab course.

METHODS

In this phase 2, dose-finding study, postmenopausal women with low bone mass (T-score ≤ - 2.0 and ≥ - 3.5) received romosozumab or placebo (month 0-24) followed by placebo or denosumab (month 24-36); participants then received a year of romosozumab (month 36-48).

RESULTS

Of 167 participants who entered the month 36-48 period, 35 had been initially randomized to romosozumab 210 mg monthly. In participants who received romosozumab 210 mg monthly followed by placebo, a second romosozumab course (n = 19) increased BMD by amounts similar to their initial treatment (month 0-12) at the lumbar spine (12.4%; 12.0%, respectively) and total hip (6.0%; 5.5%, respectively). Following denosumab, a second romosozumab course (n = 16) increased BMD at the lumbar spine (2.3%) and maintained BMD at the total hip. Safety profiles were similar between first and second romosozumab courses.

CONCLUSIONS

After 12 months off-treatment, a second romosozumab course again led to rapid and large BMD gains. Following denosumab, BMD gains with romosozumab were smaller than with initial treatment. No new safety findings were observed during the second course.

4284The combined use of radiofrequency-ablation and balloon-dilation (CURB) in the creation of a stable inter-atrial communication: first-in-man use for patients with severe pulmonary arterial hypertension

Background

Recent preclinical research has suggested that combined use of radiofrequency-ablation and balloon-dilation (CURB) had the potential to create a stable inter-atrial communication. However, the related clinical data is still absent.

Purpose

This study describes the first-in-man use of CURB in the patients with severe pulmonary arterial hypertension (PAH).

Methods

Under the guidance of fluoroscopy and intra-cardiac echocardiography, CURB was attempted in 3 patients with severe PAH (age: 35.0±12.1 years, one idiopathic PAH and two PAH related to repaired congenital heart disease). With the aid of 3D location system, fossae ovalis was ablated with radiofrequency. Then the graded balloon-dilation was performed after transseptal puncture, and radiofrequency-ablation was repeated around the rim of fenestration created with balloon-dilation. The exercise capacity and fenestration-size were followed up.

Results

CURB was performed successfully in all 3 patients, and pulmonary vascular resistance was 30.3±10.9 Wood units. The fenestration size was 5.0±1.0 mm (range: 4–6 mm), and systemic arterial oxygen saturation decreased by 4.7±0.6% (range: 4–5%). World Health Organization functional class increased by 1.6±0.5 (P<0.001) and cardiac index increased by 0.58±0.34 L/min/m2 (P<0.001). In addition, exercise capacity improved significantly (+63.7 meters, P<0.001). Follow-up (6.0±1.0 months; range: 5–7 months) showed that all fenestrations were stable (P=0.808), and no complication occurred.

Figure 1. The combined use of radiofrequency-ablation and balloon-dilation (CURB) was performed in the patient with severe PAH. Left figures showed the procedure of CURB. Middle figures showed the created fenestration with MSCT, and the morphology and size of fenestration was provided in the right-inferior panel. In addition, the sizes of right atrium and ventricle were alleviated with increase of left atrium. Right figures indicated that the fenestration-size was stable during follow-up (one week, one month and six months, respectively).

Conclusions

In patients with severe PAH, CURB is feasible and effective to create a stable inter-atrial communication. Further research was required to evaluate the long-term result of this novel approach.

ClinicalTrials.gov ID: NCT03554330.

Acknowledgement/Funding

National Natural Science Foundation of China (81670283) and Beijing Natural Science Foundation (7162160)

[Analysis and comparison of the clinical features and prognosis between extra - gastrointestinal stromal tumors and duodenal gastrointestinal stromal tumors]

Objective: To investigate the differences of clinicopathological features, diagnosis, treatment and prognosis between patients with extra-gastrointestinal stromal tumors (EGIST) and duodenal gastrointestinal stromal tumors (DGIST). Methods: A retrospective case - control study was performed. Case inclusion criteria: (1) tumor confirmed by histology and pathology; (2) primary tumor locating in the extra - gastrointestinal tract or duodenum; (3) without other synchronous tumors; (4) complete clinical and pathological data. Clinical data of 20 EGIST patients and 32 DGIST patients from March 2011 to September 2016 at Department of Gastrointestinal Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine were retrospectively collected and analyzed. The observational parameters included clinicopathological characteristics, treatment and prognosis conditions. Continuous data of abnormal distribution were expressed as median (range) and compared using the Mann-Whitney U-test. Survival curves were drawn by the Kaplan-Meier method and compared with the Log-rank test. Results: Of the 20 EGIST patients, 8 were males and 12 were females with age of 61.0 (30.0 to 86.0) years and of the 32 DGIST patients, 12 were males and 20 were females with age of 55.5 (27.0 to 70.0) years. Compared with DGIST patients, EGIST patients were older (U=188.000, P=0.012], had larger tumor size [10.0 (3.0 to 29.0) cm vs. 4.0 (1.5 to 10.0) cm, U=98.500, P<0.001] and higher ratio of high risk classification [85.0% (17/20) vs. 12.5% (4/32), χ(2)=26.870, P<0.001]. Among the 20 EGIST patients, 5 were diagnosed with distal metastasis and received imatinib (400 mg/d), and the other 15 patients underwent radical resection who were included in survival analysis. All the 32 DGIST patients underwent radical resection. The median follow-up of whole group was 43 (14 to 76) months. The 3-year recurrence/metastasis-free survival rate of 15 cases undergoing radical resection in the EGIST group was 85.6%, which was lower than that of the DGIST group (88.6%), and the difference was not statistically significant (P=0.745). There was no significant difference in the 3-year overall survival rate between the EGIST group (92.9%) and the DGIST group (100%) (P=0.271). Conclusions: As compared to DGIST, EGIST mostly occurs in those with older age, larger tumor size and higher risk grade. The prognosis of EGIST patients after radical resection is similar to that of DGIST patients.

[Laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis]

Objective: To investigate the clinical value of laparoscopic peritoneal dialysis catheter implantation in peritoneal chemotherapy for gastric cancer with peritoneal metastasis. Methods: From January 2019 to June 2019, the clinical data of 6 patients diagnosed as gastric cancer with peritoneal metastasis were retrospectively analyzed in the Gastrointestinal Surgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine. Five were male and 1 was female. The median age was 69.5 (28-77) years. The median body mass index (BMI) was 22.8 (19.6-23.5). All procedures were performed under general anesthesia with endotracheal intubation. The patient's body position and facility layout in the operating room were consistent with those of laparoscopic gastrectomy. The operator's position: the main surgeon was located on the right side of the patient, the first assistant stood on the left side of the patient, and the scopist stood between the patient's legs. Surgical procedure: (1) trocar location: three abdominal trocars was adopted, with one 12 mm umbilical port for the 30° laparoscope (point A). Location of the other two trocars was dependent on the procedure of exploration or biopsy as well as the two polyester cuff position of the peritoneal dialysis catheter: Usually one 5 mm port in the anterior midline 5 cm inferior to the umbilicus point was selected as point B to ensure that the distal end of the catheter could reach the Douglas pouch. The other 5 mm port was located in the right lower quadrant lateral to the umbilicus to establish the subcutaneous tunnel tract, and the proximal cuff was situated 2 cm away from the desired exit site (point C).(2) exploration of the abdominal cavity: a 30° laparoscope was inserted from 12 mm trocar below the umbilicus to explore the entire peritoneal cavity. The uterus and adnexa should be explored additionally for women. Once peritoneal metastasis was investigated and identified, primary laparoscopic peritoneal dialysis catheter implantation was performed so as to facilitate subsequent peritoneal chemotherapy. Ascites were collected for cytology in patients with ascites. (3) peritoneal dialysis catheter placement: the peritoneal dialysis catheter was introduced into the abdominal cavity from point A. Under the direct vision of laparoscopy, 2-0 absorbable ligature was reserved at the expected fixation point of the proximal cuff (point B) for the final knot closure. Non-traumatic graspers were used to pull the distal cuff of peritoneal dialysis catheter out of the abdominal cavity through point B. The 5-mm trocar was removed simultaneously, and the distal cuff was fixed between bilateral rectus sheaths at the anterior midline port site preperitoneally. To prevent subsequent ascites and chemotherapy fluid extravasation, the reserved crocheted wire was knotted. From point C the subcutaneous tunnel tract was created before the peritoneal steath towards the port site lateral to the umbilicus. Satisfactory catheter irrigation and outflow were then confirmed. Chemotherapy regimen after peritoneal dialysis catheterization: all patients began intraperitoneal chemotherapy on the second day after surgery. On the 1st and 8th day of each 3-weeks cycle, paclitaxel (20 mg/m(2)) was administered through peritoneal dialysis catheter, and paclitaxel (50 mg/m(2)) was injected intravenously. Meanwhile, S-1 was orally administered twice daily at a dose of 80 mg·m(-2)·d(-1) for 14 consecutive days followed by 7-days rest. To observe the patients' intraoperative and postoperative conditions. Results: All the procedures were performed successfully without intraoperative complications or conversion to laparotomy. No 30 day postoperative complications were observed. The median operative time was 33.5 (23-38) min. The median time to first flatus was 1(1-2) days, and the median postoperative hospital stay was 3 (3-4) days, without short-term complications within 30 days postoperatively. The last follow-up was up to July 10, 2019, and the patients were followed for 4(1-6) months. No ascites extravasation was observed and no death occurred in the 6 patients. There was no catheter obstruction or peritoneal fluid extravasation during and after chemotherapy. Conclusion: Laparoscopic peritoneal dialysis catheter implantation was safe and feasible for patients with peritoneal metastasis of gastric cancer. The abdominal exploration, tumor staging and the abdominal chemotherapy device implantation can be completed simultaneously, which could simplify the surgical approach, improve the quality of life for patients and further propose a new direction for the development of abdominal chemotherapy.

Texture analysis of multi-phase MRI images to detect expression of Ki67 in hepatocellular carcinoma

AIM

To determine whether texture analysis of preoperative magnetic resonance imaging (MRI) images could be used to detect Ki67 expression, a widely used cell proliferation marker in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In total, 83 patients were included, 25 with low Ki67 (Ki67 ≤10%) HCC expression and 58 with high Ki67 (Ki67 ≥10%) HCC expression as demonstrated by retrospective surgical evaluation. All patients were examined using a 3 T MRI unit with one standard protocol. The region of interest was drawn manually by one radiologist. Texture analysis included histogram, co-occurrence matrix, run-length matrix, gradient, auto-regressive model, and wavelet transform features as calculated by MaZda (version 4.6; quantitative texture analysis software). The features reduced by the Fisher, probability of classification error, and average correlation coefficient (POE+ACC), mutual information were used to select the features that predicted Ki67 proliferation status with highest accuracy and then using the B11 program for data analysis and classification.

RESULTS

The misclassification rate of the principal component analysis (PCA) in the hepatobiliary phase (HBP), T2-weighted imaging (T2WI), arterial phase (AP), and portal vein phase (PVP) was 36/83 (43.37%), 35/82 (42.68%), 40/83 (48.19%), and 34/83 (40.96%), respectively. The misclassification of the linear discriminant analysis in HBP, T2WI, AP, and PVP phase was 13/83 (15.66%), 21/82 (25.61%), 9/83 (10.84%), and 8/83 (9.64%), respectively. The misclassification of the nonlinear discriminant analysis in HBP, T2WI, AP, and PVP phase was 7/83 (8.43%), 6/82 (7.32%), 5/83 (6.02%), and 7/83 (8.43%), respectively.

CONCLUSIONS

Texture analysis of HBP, AP, and PVP were helpful for predicting Ki67 expression and may provide a less-invasive method to investigate critical histopathology markers for HCC.

Myocardial Infarction Detection Based on Multi-lead Ensemble Neural Network

Automatic myocardial infarction (MI) detection using an electrocardiogram (ECG) is of great significance for improving the survival rate of patients. In this study, we propose a multi-lead ensemble neural network (MENN) to distinguish anterior myocardial infarction (AMI) and inferior myocardial infarction (IMI) from healthy control (HC) respectively. In the study, three kinds of sub-networks and multi-lead ECG signals are combined, which fully explores the information of ECG signals and improves the classification performance. The algorithm is evaluated on the PTB database by 5-fold inter-subject cross-validation and the sensitivity (Se), specificity (Sp) and area under the curve (AUC) of AMI detection are 98.35%, 97.49%, 97.92%; The Se, Sp, and AUC of IMI detection are 93.17%, 92.02%, 92.60%. The proposed method achieves the state of the art results on both tasks and outperforms the baseline methods. Hence, the proposed method is potential for automatic MI diagnosis.

Small hepatocellular carcinoma: using MRI to predict histological grade and Ki-67 expression

AIMS

To investigate the predictive indicators of small aggressive hepatocellular carcinomas by examining the association between preoperative magnetic resonance imaging (MRI) parameters and Ki-67 expression and histological grade.

MATERIALS AND METHODS

Sixty patients with small hepatocellular carcinomas (tumour diameter: ≤3 cm, tumour numbers: ≤2) who underwent curative resection or biopsy after contrast-enhanced and diffusion-weighted MRI were evaluated retrospectively. Signal intensity (SI) of the whole lesion and erector spinae muscle was measured quantitatively. Tumour-to-muscle SI ratio was calculated. The association between these MRI parameters and histological grade and Ki-67 level was then investigated.

RESULTS

There was a significant correlation between tumour-to-muscle SI ratio and histological grade in tissues captured during the non-enhanced T1-weighted (p=0.001), arterial phase (p=0.001), and portal venous phase (p=0.036) of dynamic contrast-enhanced MRI and apparent diffusion coefficient (p=0.027). Arterial inhomogeneous enhancement was also correlated with high-Ki-67 expression (p=0.032).

CONCLUSIONS

Preoperative MRI may serve as a non-invasive tool for prediction of small, aggressive hepatocellular carcinomas, which may otherwise be treated conservatively.

Electrical detection of current generated spin in topological insulator surface states: Role of interface resistance

Current generated spin polarization in topological insulator (TI) surface states due to spin-momentum locking has been detected recently using ferromagnet/tunnel barrier contacts, where the projection of the TI spin onto the magnetization of the ferromagnet is measured as a voltage. However, opposing signs of the spin voltage have been reported, which had been tentatively attributed to the coexistence of trivial two-dimensional electron gas states on the TI surface which may exhibit opposite current-induced polarization than that of the TI Dirac surface states. Models based on electrochemical potential have been presented to determine the sign of the spin voltage expected for the TI surface states. However, these models neglect critical experimental parameters which also affect the sign measured. Here we present a Mott two-spin current resistor model which takes into account these parameters such as spin-dependent interface resistances, and show that such inclusion can lead to a crossing of the voltage potential profiles for the spin-up and spin-down electrons within the channel, which can lead to measured spin voltages of either sign. These findings offer a resolution of the ongoing controversy regarding opposite signs of spin signal reported in the literature, and highlight the importance of including realistic experimental parameters in the model.

Exosomal Wnt-induced dedifferentiation of colorectal cancer cells contributes to chemotherapy resistance

Cancer stem cells (CSCs) are inherently resistant to chemotherapy, and CSCs in chemotherapy-failed recurrent tumors are enriched; however, the cellular origin of chemotherapy-induced CSC enrichment remains unclear. Communication with stromal fibroblasts may induce cancer cell dedifferentiation into CSCs through secreted factors. We recently demonstrated that fibroblast-derived exosomes promote chemoresistance in colorectal cancer (CRC). Here, we report that fibroblasts confer CRC chemoresistance via exosome-induced reprogramming (dedifferentiation) of bulk CRC cells to phenotypic and functional CSCs. At the molecular level, we provided evidence that the major reprogramming regulators in fibroblast-exosomes are Wnts. Exosomal Wnts were found to increase Wnt activity and drug resistance in differentiated CRC cells, and inhibiting Wnt release diminished this effect in vitro and in vivo. Together, our results indicate that exosomal Wnts derived from fibroblasts could induce the dedifferentiation of cancer cells to promote chemoresistance in CRC, and suggest that interfering with exosomal Wnt signaling may help to improve chemosensitivity and the therapeutic window.

Plant growth promotion and suppression of bacterial leaf blight in rice by Paenibacillus polymyxa Sx3

The effects and mechanisms of Paenibacillus polymyxa Sx3 on growth promotion and the suppression of bacterial leaf blight in rice were evaluated in this study. The results from a plate assay indicated that Sx3 inhibited the growth of 20 strains of Xanthomonas oryzae pv. oryzae (Xoo). Rice seedling experiments indicated that Sx3 promoted plant growth and suppressed bacterial leaf blight. In addition, bacteriological tests showed that Sx3 was able to fix nitrogen, solubilize phosphate and produce indole acetic acid, indicating that various mechanisms may be involved in the growth promotion by Sx3. The culture filtrate of P. polymyxa Sx3 reduced bacterial growth, biofilm formation and disrupted the cell morphology of Xoo strain GZ 0005, as indicated by the transmission and scanning electron microscopic observations. In addition, MALDI-TOF MS analysis revealed that Sx3 could biosynthesize two types of secondary metabolites fusaricidins and polymyxin P. In summary, this study clearly indicated that P. polymyxa Sx3 has strong in vitro and in vivo antagonistic activity against Xoo, which may be at least partially attributed to its production of secondary metabolites. SIGNIFICANCE AND IMPACT OF THE STUDY: Antagonistic bacteria can grow well in their originating environment. However, it is unclear whether antagonistic bacteria were able to survive in different ecological environments. This study revealed that Paenibacillus polymyxa Sx3 isolated from rhizosphere soil of cotton significantly promoted the plant growth and suppressed bacterial leaf blight in rice. Therefore, it could be inferred that P. polymyxa Sx3 has the potential to be used as biocontrol agents in plants grown in different ecological environments.

Theoretical investigation on the optical and EPR spectra for Cu2+ -doped ZnO-CdS nanocomposites

The three optical absorption bands and EPR parameters of the [CuO6 ]10- center in the ZnO-CdS composite nanopowders are theoretically studied from the perturbation formulas based on the cluster approach. In the formulas, the contributions to EPR parameters arising from the ligand orbital and spin-orbit coupling interactions via covalence effect are considered. For the studied [CuO6 ]10- cluster, the Cu-O bond lengths are suggested to show a relative elongation ratio ρ (≈ 4.1%) along the z-axis due to Jahn-Teller effect. The defect models suggested in this work are different from the previous assumption that the impurity Cu2+ can replace the host Zn2+ site when it enters the lattices of the ΖnO and ΖnS nanocrystals, forming the tetrahedral [CuΧ4 ]6- clusters (Χ = O, S). The validity of the proposed model is discussed. The differences between the present calculations and the previous ones for the interstitial Cu2+ center in ZnO nanocrystals are analyzed in view of the dissimilar impurity behaviors due to the new composition CdS and distinct preparation conditions.