Cardiac MRI feature-tracking-derived torsion mechanics in systolic and diastolic dysfunction in systemic light-chain cardiac amyloidosis

AIM

To describe the myocardial torsion mechanics in cardiac amyloidosis (CA), and evaluate the correlations between left ventricle (LV) torsion mechanics and conventional parameters using cardiac magnetic resonance imaging feature tracking (CMR-FT).

MATERIALS AND METHODS

One hundred and thirty-nine patients with light-chain CA (AL-CA) were divided into three groups: group 1 with preserved systolic function (LV ejection fraction [LVEF] ≥50%, n=55), group 2 with mildly reduced systolic function (40% ≤ LVEF <50%, n=51), and group 3 with reduced systolic function (LVEF <40%, n=33), and compared with age- and gender-matched healthy controls (n=26). All patients underwent cine imaging and late gadolinium-enhancement (LGE). Cine images were analysed offline using CMR-FT to estimate torsion parameters.

RESULTS

Global torsion, base-mid torsion, and peak diastolic torsion rate (diasTR) were significantly impaired in patients with preserved systolic function (p<0.05 for all), whereas mid-apex torsion and peak systolic torsion rate (sysTR) were preserved (p>0.05 for both) compared with healthy controls. In patients with mildly reduced systolic function, global torsion and base-mid torsion were lower compared to those with preserved systolic function (p<0.05 for both), while mid-apex torsion, sysTR, and diasTR were preserved (p>0.05 for all). In patients with reduced systolic function, only sysTR was significantly worse compared with mildly reduced systolic function (p<0.05). At multivariable analysis, right ventricle (RV) end-systolic volume RVESV index and NYHA class were independently related to global torsion, whereas LVEF was independently related to sysTR. RV ejection fraction (RVEF) was independently related to diasTR. LV global torsion performed well (AUC 0.71; 95% confidence interval [CI]: 0.61, 0.77) in discriminating transmural from non-transmural LGE in AL-CA patients.

CONCLUSION

LV torsion mechanics derived by CMR-FT could help to monitor LV systolic and diastolic function in AL-CA patients and function as a new imaging marker for LV dysfunction and LGE transmurality.

RACK1 promotes porcine reproductive and respiratory syndrome virus infection in Marc-145 cells through ERK1/2 activation

Porcine reproductive and respiratory syndrome (PRRS) is an acute infectious disease that spreads rapidly among pigs and seriously threatens the pig industry. Activation of ERK1/2 is a hallmark of most viral infections. RACK1 interacts with a variety of kinases and membrane receptors that closely associated with viral infections and the development and progression of cancer. However, no studies have clearly defined whether RACK1 can regulate PRRSV infection through ERK1/2 activation. In our study, using RT-qPCR, immunoblotting, indirect fluorescent staining, siRNA knockdown and protein overexpression techniques, we found that downregulation of cellular RACK1 inhibited ERK1/2 activation and subsequently suppressed PRRSV infection, while overexpression of RACK1 enhanced ERK1/2 activation and PRRSV infection. Bioinformatic and Co-immunoprecipitation experimental analysis revealed that cellular RACK1 could interact with viral N protein to exert its function. We elaborated that RACK1 promoted PRRSV replication in Marc-145 cells through ERK1/2 activation. Our study provides new insights into regulating the innate antiviral immune responses during PRRSV infection and contributes to further understanding of the molecular mechanisms underlying PRRSV replication.

Long non-coding RNA LOC103222771 promotes infection of porcine reproductive and respiratory syndrome virus in Marc-145 cells by downregulating Claudin-4

Porcine reproductive and respiratory syndrome (PRRS) is an important swine disease caused by infection of porcine reproductive and respiratory syndrome virus (PRRSV), which leads to huge loss in swine industry. How to effectively control PRRS is challenging. Long non-coding RNA (lncRNA) are key regulator of viral infections and anti-virus immunological responses, therefore, further understanding of lncRNAs will aid to identification of novel regulators of viral infections and better design of prevention and control strategies to viral infection related diseases and immune disorders. We demonstrated that PRRSV infection upregulated the expression of lncRNA LOC103222771 in Marc-145 cells and porcine alveolar macrophage cells (PAMs) and that LOC103222771 is mainly located in cytoplasm. Knockdown of LOC103222771 could inhibit the PRRSV infection in Marc-145 cells. RNA-seq analysis and subsequent validation revealed increased expression of Claudin-4 (CLDN4) in Marc-145 when LOC103222771 was specifically downregulated，suggesting that LOC103222771 might be an upstream regulator of CLDN4, an important component of tight junctions for establishment of the paracellular barrier that controls the flow of molecules in the intercellular space between epithelial cells. We and others showed that Downregulation of CLDN4 could boost the infection of PRRSV. Collectively, LOC103222771/CLDN4 signal axis might be a novel mechanism of PRRSV pathogenesis, implying a potential therapeutic target against PRRSV infection.

[Notch signaling pathway inhibitor DAPT improves alcohol-induced neuronal differentiation impairment in zebrafish]

OBJECTIVE

To explore the role of the Notch signaling pathway in regulating neuronal differentiation and sensorimotor ability in a zebrafish model of fetal alcohol spectrum disorder.

METHODS

Zebrafish embryos treated with DMSO or 50 μmol/L DAPT (a Notch signaling pathway inhibitor) were examined for mortality rate, hatching rate, malformation rate, and body length at 15 days post fertilization (dpf). The mRNA expression levels of sox2, neurogenin1 and huc in the treated zebrafish embryos were detected using in situ hybridization and qRT-PCR, and their behavioral responses to strong light and vibration stimulation were observed. The zebrafish embryos were then exposed to DMSO, 1.5% ethanol, DAPT, or both ethanol and DAPT, and the changes in mRNA expression levels of sox2, neurogenin1, huc, and the Notch signaling pathway genes as well as behavioral responses were evaluated.

RESULTS

Exposure to 50 μmol/L DAPT significantly increased the mortality rate of 1 dpf zebrafish embryos (P < 0.01), decreased the hatching rate of 2 dpf embryos (P < 0.01), increased the malformation rate of 3 dpf embryos (P < 0.001), and reduced the body length of 15 dpf embryos (P < 0.05). DAPT treatment significantly downregulated sox2 mRNA expression (P < 0.01) and increased neurogenin1 (P < 0.05) and huc (P < 0.01) mRNA expressions in zebrafish embryos. The zebrafish with DAPT treatment exhibited significantly shortened movement distance (P < 0.001) and lowered movement speed (P < 0.05) in response to all the stimulation conditions. Compared with treatment with 1.5% ethanol alone, which obviously upregulated notch1a, her8a and NICD mRNA expressions in zebrafish embryos (P < 0.05), the combined treatment with ethanol and DAPT significantly increased neurogenin1 and huc mRNA expression, decreased sox2 mRNA expression (P < 0.01), and increased the moving distance and moving speed of zebrafish embryos in response to strong light stimulation (P < 0.05).

CONCLUSION

Ethanol exposure causes upregulation of the Notch signaling pathway and impairs neuronal differentiation and sensorimotor ability of zebrafish embryos, and these detrimental effects can be lessened by inhibiting the Notch signaling pathway.

Detection of haemodynamic obstruction in hypertrophic cardiomyopathy using the sub-aortic complex: a cardiac MRI and Doppler study

AIM

To investigate the "sub-aortic complex (SAC)", a new cardiac magnetic resonance imaging (CMRI)-derived parameter, for the evaluation of left ventricular (LV) outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM), compared with conventional CMRI parameters and Doppler echocardiography.

MATERIALS AND METHODS

A total of 157 consecutive patients with HCM were recruited retrospectively. The patients were divided into two groups, 87 with LVOT obstruction and 70 without obstruction. The SAC was defined as a specific anatomical SAC affecting the LVOT, which were measured on the LV three-chamber steady-state free precession (SSFP) cine image at the end-systolic phase. The relations between the existence and severity of obstruction and SAC index (SACi) were evaluated using Pearson's correlation coefficient, receiver operating characteristic (ROC) curves, and logistic regression.

RESULTS

The SACs were significantly different between the obstructive and non-obstructive groups. The ROC curves indicated that the SACi was able to discriminate obstructive and non-obstructive patients with the best predictive accuracy (AUC = 0.949, p<0.001). The SACi was an independent predictor of LVOT obstruction and there was a significant negative correlation between resting LVOT pressure gradient and SACi (r=0.72 p<0.001). In the subgroup of patients with or without severe basal septal hypertrophy, the SACi was still able to predict LVOT obstruction with excellent diagnostic accuracy (AUC = 0.944 and 0.948, p<0.001, respectively).

CONCLUSION

The SAC is a reliable and straightforward CMRI marker for assessing LVOT obstruction. It is more effective than CMRI two-dimensional flow in diagnosing the severity of obstruction in patients with HCM.

High Genetic Diversity of Porcine Sapovirus From Diarrheic Piglets in Yunnan Province, China

As one of the most important enteric viruses, sapovirus (SaV) can infect humans and a variety of animals. Until now, 19 SaV genogroups have been identified, among which 4 from human (GI, GII, GIV, and GV) and 8 from swine (GIII, GV–GXI). Porcine sapovirus (PoSaV) GIII has been prevalent in China; however, the status of PoSaV infection in Yunnan province remains unknown. In this study, 202 fecal samples were collected from piglets associated with outbreaks of acute diarrhea in Yunnan between January and May 2020. PoSaV detection revealed that the total PoSaV infection rate in Yunnan was 35.2%, with 21 PoSaV strains determined and phylogenetically analyzed. The phylogenetic tree analyses demonstrated that twenty PoSaV strains belonged to GIII and fell into five genotypes, whereas one PoSaV strain (YNQB) belonged to GV. Sequence alignments revealed deletions in VP2 region in 10 of the 20 GIII strains, as well as deletions and insertions in VP1 region of the GV strain (YNQB). Furthermore, genomic recombination analyses showed that two GIII strains (YNAN and YNJD) were recombinants, closely related to reference sequences MK965898 and LC215880, MK965898 and FJ387164, respectively. In summary, PoSaV-GIII strains were identified in Yunnan in 2020, and for the first time, a PoSaV-GV strain was identified from China, whereas the comprehensive analyses illustrated high genetic diversity of Yunnan PoSaV strains. This study may shed new light on the current PoSaV infections in Yunnan and pave the way toward further control of the PoSaV infections in China.

Comparative Analyses of Antibiotic Resistance Genes in Jejunum Microbiota of Pigs in Different Areas

Antibiotic resistance genes (ARGs) are emerging environmental contaminants that threaten human and animal health. Intestinal microbiota may be an important ARGs repository, and intensive animal farming is a likely contributor to the environmental burden of ARGs. Using metagenomic sequencing, we investigated the structure, function, and drug resistance of the jejunal microbial community in Landrace (LA, Kunming), Saba (SB, Kunming), Dahe (DH, Qujing), and Diannan small-ear piglets (DS, Xishuangbanna) from different areas in Yunnan Province, China. Remarkable differences in jejunal microbial diversity among the different pig breeds, while the microbial composition of pig breeds in close areas tends to be similar. Functional analysis showed that there were abundant metabolic pathways and carbohydrate enzymes in all samples. In total, 32,487 ARGs were detected in all samples, which showed resistance to 38 categories of drugs. The abundance of ARGs in jejunum was not significantly different between LA and SB from the same area, but significantly different between DS, DH and LA or SB from different areas. Therefore, the abundance of ARGs was little affected by pig breeds and microorganism community structure, but it was closely related to geographical location. In addition, as a probiotic, Lactobacillus amylovorus is also an important ARGs producing bacterium. Our results revealed the antibiotic exposure and intestinal microbial resistance of farms in the study areas, which could provide basic knowledge and potential strategies for rational use of antibiotics and reducing the risk of ARGs transmission in animal husbandry.

[Soluble egg antigen of Schistosoma japonicum induces macrophage apoptosis in mice]

OBJECTIVE

To investigate the dynamic changes of macrophage numbers and apoptosis during Schistosoma japonicum infection, and to investigate the possible mechanisms of macrophage apoptosis induced by S. japonicum soluble egg antigen (SEA).

METHODS

C57BL/6 mice at ages of 6~8 weeks were randomly divided into 4 groups, including three experimental groups and a normal control group. Each mouse in the experimental groups was infected with (12 ± 1) cercariae of S. japonicum via the abdominal skin, and all mice in an experimental group were sacrificed 3, 5, 8 weeks post-infection, respectively, while mice in the control group were not infected with S. japonicum cercariae and sacrificed on the day of S. japonicum infection in the experimental group. Mouse liver specimens and peritoneal exudation cells were sampled in each group, and the dynamic changes of macrophage numbers and apoptosis were detected. Mouse peritoneal macrophages were isolated, purified and treated with S. japonicum SEA, PBS and ovalbumin (OVA) in vitro, and the macrophage apoptosis was detected using flow cytometry. The mRNA and protein expression of BCL-2 protein family members were determined in macrophages using real-time quantitative PCR (qP-CR) and Western blotting assays, and the activation of caspase 3 was determined using flow cytometry and Western blotting. In addition, macrophages were in vitro treated with S. japonicum SEA in presence of a caspase inhibitor, H₂O₂ or N-acetyl-L-cysteine, and the apoptosis of macrophages was detected using flow cytometry.

RESULTS

The total macrophage numbers continued to increase in mouse liver [(0.873 ± 0.106) × 106, (2.737 ± 0.460) × 10⁶ and (3.107 ± 0.367) × 10⁶ cells, respectively; F = 81.900, P < 0.01] and peritoneal specimens [(5.282 ± 1.136) × 105, (7.500 ± 1.200) × 10⁵ and (12.800 ± 0.800) × 10⁵ cells, respectively; F = 55.720, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum, and the numbers of apoptotic macrophages also continued to increase in mouse liver [(0.092 ± 0.018) × 10⁶, (0.186 ± 0.025) × 10⁶ and (0.173 ± 0.0270) × 10⁶ cells; F = 57.780, P < 0.01] and peritoneal specimens [(0.335 ± 0.022) × 10⁵, (0.771 ± 0.099) × 10⁵ and (1.094 ± 0.051) × 10⁵ cells; F = 49.460, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum. The apoptotic rate of SEA-treated macrophages [(24.330 ± 0.784)%] was significantly higher than that of PBS-[(18.500 ± 1.077)%] and OVA-treated macrophages [(18.900 ± 1.350)%] (both P values < 0.01). There were no significant differences in the mRNA or protein expression of Bcl-2 [Bcl - 2 mRNA expression: (1.662 ± 0.943) vs. (1.000 ± 0.000), t = 1.215, P > 0.05; BCL protein expression: (0.068 ± 0.004) vs. (0.070 ± 0.005), t = 0.699, P > 0.05], Bax [Bax mRNA expression: (0.711 ± 0.200) vs. (1.000 ± 0.000), t = 2.507, P > 0.05; BAX protein expression: (0.089 ± 0.005) vs. (0.097 ± 0.003), t = 2.232, P > 0.05] and Bak [Bak mRNA expression: (1.255 ± 0.049) vs. (1.00 ± 0.00), t = 0.897, P > 0.05; BAK protein expression: (0.439 ± 0.048) vs. (0.571 ± 0.091), t = 2.231, P > 0.05] between in SEA- and PBS-treated macrophages. S. japonicum SEA induced macrophage apoptosis in the presence of a caspase inhibitor (F = 0.411, P > 0.05); however, SEA failed to induce macrophage apoptosis in the presence of H₂O₂ or NAC (F = 11.880 and 9.897, both P values < 0.05).

CONCLUSIONS

S. japonicum SEA may induce macrophage apoptosis through promoting reactive oxygen species expression during S. japonicum infections in mice.

Development and validation of an individualized nomogram for predicting the high-volume (> 5) central lymph node metastasis in papillary thyroid microcarcinoma

PURPOSE

Papillary thyroid microcarcinoma (PTMC) frequently presents a favorable clinical outcome, while aggressive invasiveness can also be found in some of this population. Identifying the risk clinical factors of high-volume (> 5) central lymph node metastasis (CLNM) in PTMC patients could help oncologists make a better-individualized clinical decision.

METHODS

We retrospectively reviewed the clinical characteristics of adult patients with PTC in the Surveillance, Epidemiology, and End Results (SEER) database between Jan 2010 and Dec 2015 and in one medical center affiliated to Chongqing Medical University between Jan 2018 and Oct 2020. Univariate and multivariate logistic regression analyses were used to determine the risk factors for high volume of CLNM in PTMC patients.

RESULTS

The male gender (OR = 2.02, 95% CI 1.46-2.81), larger tumor size (> 5 mm, OR = 1.64, 95% CI 1.13-2.38), multifocality (OR = 1.87, 95% CI 1.40-2.51), and extrathyroidal invasion (OR = 3.67; 95% CI 2.64-5.10) were independent risk factors in promoting high-volume of CLNM in PTMC patients. By contrast, elderly age (≥ 55 years) at diagnosis (OR = 0.57, 95% CI 0.40-0.81) and PTMC-follicular variate (OR = 0.60, 95% CI 0.42-0.87) were determined as the protective factors. Based on these indicators, a nomogram was further constructed with a good concordance index (C-index) of 0.702, supported by an external validating cohort with a promising C-index of 0.811.

CONCLUSION

A nomogram was successfully established and validated with six clinical indicators. This model could help surgeons to make a better-individualized clinical decision on the management of PTMC patients, especially in terms of whether prophylactic central lymph node dissection and postoperative radiotherapy should be warranted.

Construction and validation of a nomogram for predicting cervical lymph node metastasis in classic papillary thyroid carcinoma

PURPOSE

Patients with papillary thyroid carcinoma (PTC) frequently present a relatively poor prognosis when they coexist with cervical lymph node metastasis (LNM). Moreover, it remains controversial whether prophylactic lymph node dissection (LND) should be performed for patients without clinically lymph node metastasis. Thus, we hereby develop a nomogram for predicting the cervical LNM (including central and lateral LNM) in patients with PTC.

METHODS

We retrospectively reviewed the clinical characteristics of adult patients with PTC in the surveillance, epidemiology, and end results (SEER) database between 2010 and 2015 and in our Department of Breast and Thyroid Surgery in the Second Affiliated Hospital of Chongqing Medical University between 2019 and 2020.

RESULT

A total of 21,972 patients in the SEER database and 747 patients in our department who met the inclusion criteria were enrolled in this study. Ultimately, six clinical features including age, gender, race, extrathyroidal invasion, multifocality, and tumor size were identified to be associated with cervical LNM in patients with PTC, which were screened to develop a nomogram. This model had satisfied discrimination with a concordance index (C-index) of 0.733, supported by both internal and external validation with a C-index of 0.731 and 0.716, respectively. A decision curve analysis was subsequently made to evaluate the feasibility of this nomogram for predicting cervical LNM. Besides, a positive correlation between nomogram score and the average number of lymph node metastases was observed in all groups.

CONCLUSION

This visualized multipopulational-based nomogram model was successfully established. We determined that various clinical characteristics were significantly associated with cervical LNM, which would be better helping clinicians make individualized clinical decisions for PTC patients.

POS0664 A MULTICENTER RANDOMIZED STUDY IN RHEUMATOID ARTHRITIS TO COMPARE IGURATIMOD, METHOTREXATE, OR COMBINATION: 52 WEEK EFFICACY AND SAFETY RESULTS OF THE SMILE TRIAL

Background:

Iguratimod (IGU) has demonstrated efficacy and safety for active rheumatoid arthritis (RA) patients in double-blind clinical trials in China and Japan as a new disease-modifying anti-rheumatic drug (DMARD). There are no studies evaluating the radiographic progression of structural joint damage of IGU for the treatment of RA using the mTSS as the primary endpoint.

Objectives:

Our study was to evaluate the efficacy and safety of IGU monotherapy and IGU combined methotrexate (MTX) compared with MTX monotherapy, including the inhibitory effects of joint destruction.

Methods:

This randomized, double-blind, parallel-controlled, multicenter study in patients with active RA who have not previously used MTX and biological DMARDs (bDMARDs) (ClinicalTrials.gov Identifier NCT01548001) was carried out in China. Patients were randomized 1:1:1 to receive IGU 25 mg twice a day (bid), MTX 10mg once a week(qw) for the first 4 weeks and 15 mg once a week(qw) for week 5 to 52, or IGU combined MTX (IGU+MTX) for 52 weeks. The primary endpoints were to assess and compare American College of Rheumatology 20% (ACR20) response and the change of modified total Sharp scoring (mTSS) score over 52 weeks (Intention-to-treat, ITT analysis). The non-inferiority test was used to analyze the difference of ACR20 response at 52 weeks between the IGU monotherapy and the MTX monotherapy arms, and the non-inferiority limit value was 10%. The difference test was used for the comparison between the IGU+MTX and MTX monotherapy arms. Two-way ANOVA was used to analyze the difference of the changes of mTSS score of each arm compared with baseline value (0 week).

Results:

A total of 895 patients were randomized to IGU 25mg bid (n =297), MTX 10-15mg qw(n=293), and IGU+MTX (n=305). Baseline characteristics were comparable between the arms (Table 1).

Table 1.

Demographic and Other Baseline Characteristics (SAS)

IGUMTXIGU+MTXNumber of Subjects297293305Age, mean (SD) years46.87(10.67)47.63(10.70)48.37(10.69)Female/male, %77.44/22.5679.18/20.8278.03/21.97Duration of RA, mean(SD) years11.67±7.1611.60±7.9811.67±7.27CRP, mean(SD) mg/L222.32±35.4720.67±26.6119.74±31.38Tender joint count, mean (SD)14.59±9.1614.83±9.3014.93±9.88Swollen joint count, mean (SD)9.81±6.639.73±7.209.51±6.22DAS28-CRP, mean (SD)5.084±0.9945.102±0.9795.103±0.956HAQ score, mean (SD)15.82±11.2515.24±10.9316.06±10.92

SAS: Safety Analysis Set; CRP: C-reactive protein;

DAS28: disease activity score; HAQ: Health Assessment Questionnaire

The study met its primary endpoints. More concretely, IGU monotherapy and IGU+MTX were found to be superior to MTX at week 52 with a higher ACR20 response of 77.44%(230/297, P=0.0019) and 77.05%(235/305, P=0.0028) versus 65.87%(193/293) (fig 1). As shown in fig 1, the structural remission (ΔmTSS≤0.5) was statistically significant for IGU monotherapy (57.4%, P=0.0308) but not for IGU+MTX arm (55%) versus MTX monotherapy (47.8%).

Overall incidence of the adverse events (AEs) leading to study discontinuation were reported in 13.8% (41/297) in IGU monotherapy arm, 11.26% (33/293) in MTX monotherapy arm and 11.51% (35/305) patients in IGU+MTX arm. The incidence of adverse drug reactions (ADR) leading to study discontinuation were 11.45% (34/297), 8.53% (25/293) and 9.21% (28/305), respectively. There was no one death and no significant difference in all the safety indicators among the three arms.

Conclusion:

Iguratimod alone or in combination with MTX demonstrated superior efficacy with acceptable safety compared to MTX for patients with active RA who have not previously used MTX bDMARDs.

Disclosure of Interests:

None declared

Classical swine fever virus infection suppresses claudin-1 expression to facilitate its replication in PK-15 cells

Classical swine fever (CSF) is one of the most epidemic viral diseases in swine industry. The causative pathogen is CSF virus (CSFV), a small enveloped RNA virus of Flaviviridae family. Claudin-1 was reported to be involved in the infections of a number of viruses, including many from Flaviviridae family, but no studies have investigated the role of porcine claudin-1 during CSFV infection in PK-15 cells. In this study, on the one hand, we demonstrated that CSFV infection reduced the claudin-1 expression at both mRNA and protein levels; on the other hand, CSFV infection was enhanced after claudin-1 knockdown, but inhibited by claudin-1 overexpression in a dose-dependent manner. Furthermore, negative correlation was demonstrated between the claudin-1 expression and CSFV titer. In conclusion, claudin-1 might be a barrier for CSFV infection in PK-15 cells, while CSFV bypasses the barrier through lysosome mediated degradation of claudin-1, which could be repressed by bafilomycin A1. Although the elaborate mechanisms how claudin-1 plays its roles in CSFV infection require further investigations, this study may advance our understanding of the molecular host-pathogen interaction mechanisms underlying CSFV infection and suggests enhancement of porcine claudin-1 as a potential preventive or therapeutic strategy for CSF control.

Peripheral blood T-cell receptor repertoire as a predictor of clinical outcomes in gastrointestinal cancer patients treated with PD-1 inhibitor

BACKGROUND

Identifying valid biomarkers for patient selection impressively promotes the success of anti-PD-1 therapy. However, the unmet need for biomarkers in gastrointestinal (GI) cancers remains significant. We aimed to explore the predictive value of the circulating T-cell receptor (TCR) repertoire for clinical outcomes in GI cancers who received anti-PD-1 therapy.

METHODS

137 pre- and 79 post-treated peripheral blood samples were included. The TCR repertoire was evaluated by sequencing of complementarity-determining region 3 (CDR3) in the TRB gene. The Shannon index was used to measure the diversity of the TCR repertoire, and Morisita's overlap index was used to determine TCR repertoire similarities between pre- and post-treated samples.

RESULTS

Among all enrolled patients, 76 received anti-PD-1 monotherapy and 61 received anti-PD-1 combination therapy. In the anti-PD-1 monotherapy cohort, patients with higher baseline TCR diversity exhibited a significantly higher disease control rate (77.8% vs. 47.2%; hazard ratio [HR] 3.92; 95% confidence interval [CI] 1.14-13.48; P = 0.030) and a longer progression-free survival (PFS) (median: 6.47 months vs. 2.77 months; HR 2.10; 95% CI 1.16-3.79; P = 0.014) and overall survival (OS) (median: NA vs. 8.97 months; HR 3.53; 95% CI 1.49-8.38; P = 0.004) than those with lower diversity. Moreover, patients with a higher TCR repertoire similarity still showed a superior PFS (4.43 months vs. 1.84 months; HR 13.98; 95% CI 4.37-44.68; P < 0.001) and OS (13.40 months vs. 6.12 months; HR 2.93; 95% CI 1.22-7.03; P = 0.016) even in the cohort with lower baseline diversity. However, neither biomarker showed predictive value in the anti-PD-1 combination therapy cohort. Interestingly, the combination of TCR diversity and PD-L1 expression can facilitate patient stratification in a pooled cohort.

CONCLUSION

The circulating TCR repertoire can serve as a predictor of clinical outcomes in anti-PD-1 therapy in GI cancers.

[Role of cardiac magnetic resonance imaging in myocarditis patients with biopsy negative: a retrospective case series study]

Objective: To analyze the cardiac magnetic resonance (CMR) imaging feature of clinically diagnosed myocarditis patients with negative endocardial biopsy (EMB) results, and to further demonstrate the diagnostic value of CMR in these patients. Methods: This was a retrospective case series study. Fourteen patients, who were clinically diagnosed as myocarditis according to 2013 European Society of Cardiology (ESC) clinical diagnostic criteria for myocarditis, but with negative EMB results, were enrolled. All patients underwent CMR examinations. The morphological, functional and histological changes of the heart were assessed based on black blood sequence, cine sequence, T2W-STIR sequence and contrast agent late gadolinium enhancement,(LGE). Results: There were 10 males and 4 females in this cohort, the age was (25.6±13.2) years. The interval between symptom onset and CMR was 21 (13, 60) days, and the interval between symptom onset and EMB was 19 (9, 40) days. There were 13 patients with abnormal CMR results including myocardial oedema, fibrosis, decreased ejection fraction, pericardial effusion or increased cardiac chamber dimension. Nine out of 14 patients had CMR morphological and/or functional abnormalities, including 1 case of left atrium enlargement, 1 case of left ventricle enlargement, 3 cases of right ventricle enlargement, 4 cases of increased left ventricular end diastolic volume index. Left ventricular ejection fraction was<50% in three cases, right ventricular ejection fraction was<40% in 5 cases, and pericardial effusion depth>3 mm was detected in 3 cases. Of the 14 patients, 11 had histological changes, of which 6 had T2 ratio≥2. Among the 10 patients (10/14) with positive LGE, the most common patterns were subepicardial LGE of the lateral wall and/or midwall LGE of the septum (n=9); 2 cases showed extensively subendocardial LGE of the left ventricular wall. No LGE involved in the right ventricular wall in the whole cohort. Conclusion: CMR plays a complementary role in the diagnosis of myocarditis in clinically diagnosed myocarditis patients with negative EMB findings.

Association between TP53 polymorphisms and chronic lymphocytic leukemia

OBJECTIVE

The aim of this study was to explore the association between TP53 gene polymorphisms (rs8068934 A>G and rs218698 C>T) and chronic lymphocytic leukemia (CLL).

PATIENTS AND METHODS

CLL patients who received treatment in our hospital were enrolled in this study as the disease group. Meanwhile, healthy subjects were taken as the control group. Peripheral blood samples were collected to detect TP53 gene polymorphisms at rs8068934 and rs218698, and the haplotype analysis was performed. The expression of TP53 was detected via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Furthermore, the survival conditions were analyzed.

RESULTS

The allele distribution at rs8068934 (p=0.046) and rs218698 (p=0.028) of TP53 gene was different between control group and disease group. A allele frequency at rs8068934 and T allele frequency at rs218698 were significantly higher in disease group (p<0.05). The genotype distribution at rs218698 of TP53 gene in disease group was also different from that in control group (p=0.038). The results demonstrated that CC genotype frequency in disease group was significantly lower than that in control group (p<0.05). Besides, the distribution of dominant model at rs8068934 (p=0.042) and recessive model at rs218698 (p=0.033) in disease group exhibited remarkable differences from control group, in which AA+AG frequency (dominant model) at rs8068934 and CC+CT frequency (recessive model) at rs218698 in disease group were significantly higher. Meanwhile, the distribution of AT (p=0.029) and GC (p=0.007) haplotypes at rs8068934 and rs218698 in disease group was evidently different from that in control group. The results indicated that disease group showed significantly higher frequency of AT haplotype and lower frequency of GC haplotype (p<0.05). Moreover, TP53 gene polymorphisms at rs8068934 were significantly associated with the levels of white blood cells (WBC) (p=0.000) and platelets (PLT) (p=0.035). Patients with GG genotype had significantly higher level of WBC, while those with AG genotype showed significantly lower level of PLT (p<0.05). TP53 gene polymorphisms at rs218698 were associated with the level of red blood cells (RBC) (p=0.000). Patients with CT genotype had a remarkably lower level of RBC (p<0.05). There were significant correlations of TP53 gene polymorphisms at rs8068934 (p=0.000) and rs218698 (p=0.000) with the expression of TP53. The expression of TP53 was lower in people with AA genotype at rs8068934 but higher in people with TT genotype at rs218698 (p<0.05). Furthermore, TP53 gene polymorphisms at rs8068934 (p=0.000) and rs218698 (p=0.000) were markedly associated with patients' survival.

CONCLUSIONS

TP53 polymorphisms are significantly correlated with the occurrence and progression of CLL.

Inhibition of porcine reproductive and respiratory syndrome virus by PKC inhibitor dequalinium chloride in vitro

As a severe disease characterized by reproductive failure and respiratory distress, porcine reproductive and respiratory syndrome (PRRS) is one of the most leading threats to the swine industry worldwide. Highly evolving porcine reproductive and respiratory syndrome virus (PRRSV) strains with distinct genetic diversity make the current vaccination strategy much less cost-effective and thus urge alternative protective host directed therapeutic approaches. RACK1-PKC-NF-κB signalling axis was suggested as a potential therapeutic target for PRRS control, therefore we tested the inhibitory effect of PKC inhibitor dequalinium chloride (DECA) on the PRRSV infection in vitro. RT-qPCR, western blot, Co-IP and cytopathic effect (CPE) observations revealed that DECA suppressed PRRSV infection and protected Marc-145 cells and porcine alveolar macrophages (PAMs) from severe cytopathic effects, by repressing the PKCα expression, the interaction between RACK1 and PKCα, and subsequently the NF-κB activation. In conclusion, the data presented in this study shed more light on deeper understanding of the molecular pathogenesis upon PRRSV infection and more importantly suggested DECA as a potential promising drug candidate for PRRS control.

Porcine RACK1 negatively regulates the infection of classical swine fever virus and the NF-κB activation in PK-15 cells

Classical swine fever (CSF) is one of the main viral diseases of swine worldwide. The causative pathogen is CSF virus (CSFV), a small enveloped RNA virus of the genus Pestivirus. Activation of NF-κB is a hallmark of most viral infections and the viral pathogens frequently kidnap NF-κB pathway for their own advantages, however, it is unclear or even controversial about whether CSFV infection can activate NF-κB signal pathway. RACK1 was shown as an interacting host protein with CSFV NS5A protein, but no studies so far have clearly defined the role of RACK1 during CSFV infection and NF-κB activation. In this study, to properly address these open questions, using RT-qPCR, western blot, indirect fluorescence staining, siRNA knockdown and protein overexpression techniques, we demonstrated that CSFV infection reduced the RACK1 expression at both mRNA and protein levels in PK-15 cells. Downregulation of cellular RACK1 enhanced CSFV infection and subsequent NF-κB activation, while RACK1 overexpression inhibited CSFV infection and the NF-κB activation. In conclusion, RACK1 is a negative cellular regulator for CSFV infection and NF-κB activation in PK-15 cells. Our work addressed a novel aspect concerning the regulation of innate antiviral immune response during CSFV infection. This study may provide some insights into the molecular mechanisms of CSFV infection in swine. However, the elaborate mechanism by which CSFV regulates NF-κB activation and how RACK1 plays its roles in CSFV infection and NF-κB induction require further in-depth studies.

Efficacy of recombinant N- and C-terminal derivative of EmIMP1 against E. maxima infection in chickens

1. Immune mapped protein-1 (IMP1) of E. maxima has been identified as a vaccine antigen candidate for E. maxima infection. 2. In the current study, the N- and C-terminal derivative of EmIMP1 were expressed in E. coli and administered to chickens. The antibody response, cell-mediated immune (CMI) response and the protective efficacy of the protein vaccines against E. maxima challenge were evaluated. 3. The results showed that C-terminal derivative of EmIMP1 vaccination could increase weight gain, reduce enteric lesions, and decrease faecal oocysts shedding. Moreover, the C-terminal derivative of EmIMP1 caused reasonable improvement in serum antibodies and the numbers of IFN-γ producing peripheral blood mononuclear cells (PBMC), as compared to the control group. 4. This study demonstrated that the C-terminal derivative of EmIMP1 could be used as a potent immunogenic candidate in the development of subunit vaccines against E. maxima infection.

Integrin β3, a RACK1 interacting protein, is critical for porcine reproductive and respiratory syndrome virus infection and NF-κB activation in Marc-145 cells

Porcine reproductive and respiratory syndrome virus (PRRSV) is the pathogen of porcine reproductive and respiratory syndrome (PRRS), which is one of the most economically harmful diseases in modern pig production worldwide. Receptor of activated protein C kinase 1 (RACK1) was previously shown to be indispensable for the PRRSV replication and NF-κB activation in Marc-145 cells. Here we identified a membrane protein, integrin β3 (ITGB3), as a RACK1-interacting protein. PRRSV infection in Marc-145 cells upregulated the ITGB3 expression. Abrogation of ITGB3 by siRNA knockdown or antibody blocking inhibited PRRSV infection and NF-κB activation, while on the other hand, overexpression of ITGB3 enhanced PRRSV infection and NF-κB activation. Furthermore, inhibition of ITGB3 alleviated the cytopathic effects and reduced the TCID₅₀ titer in Marc-145 cells. We also showed that RACK1 and ITGB3 were NF-κB target genes during PRRSV infection, and that they regulated each other. Our data indicated that ITGB3, presumably as a co-receptor, played an imperative role during PRRSV infection and NF-κB activation in Marc-145 cells. PRRSV infection activates a positive feedback loop involving the activation of NF-κB and upregulation of ITGB3 and RACK1 in Marc-145 cells. The findings would advance our elaborated understanding of the molecular host-pathogen interaction mechanisms underlying PRRSV infection in swine and suggest ITGB3 and NF-κB signaling pathway as potential therapeutic targets for PRRS control.

Identification of urinary hsa_circ _0137439 as potential biomarker and tumor regulator of bladder cancer

Cell-free circular RNAs (circRNAs) stably and abundantly exist in body fluids. In this study we aimed to investigate the potential of urinary cell-free circRNAs as a novel class of noninvasive disease biomarkers for diagnosis of bladder cancer. Differentially expressed circRNAs from 10 normal and 10 bladder cancer urine samples were firstly detected by microarray. Hsa_circ_0137439 was then screened and validated in 30 normal and 116 bladder cancer samples. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of hsa_circ_0137439. The Kaplan-Meier method was used to evaluate the significance of hsa_circ_0137439 in the prognosis of bladder cancer. We found that hsa_circ_0137439 was significantly upregulated in bladder cancer samples. Moreover, increased expression of hsa_circ_0137439 was correlated with higher tumor stage, higher tumor grade, higher lymph node status, and history of muscle-invasive bladder cancer (MIBC). Also, urinary cell-free hsa_circ_0137439 could not only differentiate bladder cancer from normal controls but also distinguish MIBC from non-muscle-invasive bladder cancer (NMIBC). Additionally, hsa_circ_0137439 in urine supernatant could serve as an independent prognostic predicator of recurrence-free survival and overall survival for patients with bladder cancer. Cell assays showed that hsa_circ_0137439 knockdown contributed to the inhibition of cell proliferation and migration via hsa_circ_0137439/miR-142-5p/ MTDH axis. In conclusion, urinary cell-free hsa_circ_0137439 could be a promising biomarker for tumor diagnosis and prognostic assessment of bladder cancer patients.

The application of PRP combined with TCP in repairing avascular necrosis of the femoral head after femoral neck fracture in rabbit

OBJECTIVE

In view of the high occurrence of avascular necrosis of the femoral head (ANFH) after femoral neck fracture and the difficulties in the treatment, our work aimed to explore the effects of platelet-rich plasma (PRP) combined with tri-calcium phosphate (TCP) on the repair of ANFH after femoral neck fracture and to provide reference for clinical treatment.

MATERIALS AND METHODS

Thirty New Zealand white rabbits were randomly divided into control group, TCP group, and PRP+TCP group. The rabbit ANFH model was established and femoral head tissues were collected. HE staining was used for histological observation. Image analysis and statistical analysis were used to calculate the New Bone Area fraction (NBA %). The levels of bone morphogenetic protein (BMP)-7, transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), interleukin (IL)-6 and tumor necrosis factor (TNF)-a in serum were detected by Enzyme-Linked ImmunoSorbent Assay (ELISA).

RESULTS

The new bone area of TCP group was significantly lower than that of PRP+TCP group (p<0.05). Compared with the control group, the levels of BMP-7, TGF-β1 and bFGF were significantly increased in both TCP and PRP+TCP groups (p<0.05), and the increase in PRP+TCP group was higher than that in TCP group. TCP and PRP+TCP can both significantly reduce the content of IL-6 and TNF-a (p<0.05); however, higher decrease was found in PRP+TCP group compared with the TCP group at 8 weeks after injection.

CONCLUSIONS

PRP combined with TCP, which can promote new bone formation and inhibit inflammatory response, showed higher efficiency in repairing ANFH than internal fixation alone.

[Cardiovascular magnetic resonance imaging characteristics and influence factors of aortic insufficiency patients with myocardial fibrosis]

Objective: To investigate the cardiovascular magnetic resonance (CMR) imaging characteristics and influence factors of aortic insufficiency (AI) patients with myocardial fibrosis. Method: This retrospective study included 59 AI patients who received CMR and transthoracic echocardiography (TTE) examinations from June 2011 to February 2015. AI patients were divided into 2 groups: bicuspid aortic valve (BAV) group (n=30) and non-BAV group (n=29). Patients were also divided into late gadolinium enhancement (LGE) group (n=27) and non-LGE group (n=32). The baseline clinical characteristics were collected through electronic medical records. Hemodynamic parameters such as grade of AI, cardiac functional parameters and LGE mass fraction (LGE%) were measured by CMR post-processing analysis. Kappa test was used to assess the consistency of AI severity between CMR and TTE, and the multivariate logistic regression analysis was performed to evaluate influence factors of myocardial fibrosis in AI patients. Results: (1) 56 (94.9%) patients were male, and the mean age was (44.2±11.0) years old. There was no significant difference in age and gender, hypertension, hyperlipidemia, alcoholic consumption between BAV and non-BAV group (all P>0.05). There were a higher proportion of smoking history (P=0.008), a lower body mass index (BMI) (P=0.020) in the LGE group than in the non-LGE group. (2) The accuracy of CMR in diagnosis of BAV was 96.7% (29/30) compared to the gold standard. In the BAV group, 20 patients (66.7%) were with fusion of left and right cusp (L-R), 5 patients (16.7%) were with fusion of right and noncoronary cusp (R-N), 5 patients (16.7%) were with fusion of left and noncoronary cusp (L-N); patients with BAV had larger left ventricular end diastolic volume index (LVEDVi), left ventricular end systolic volume index (LVESVi), higher proportion of LGE and lower left ventricular ejection fraction (LVEF) than those in non-BAV group (all P<0.05). There were 19 patients with BAV in the LGE group, the cases of L-R, R-N, L-N were 10 (52.6%), 5 (26.3%), and 4 (21.1%), respectively. In the non-LGE group, patients with BAV of L-R, R-N, L-N were 10 (90.9%), 0, and 1 (9.1%), respectively. Patients with LGE had lower body surface area (BSA), LVEF and larger LVEDVi, LVESVi, left ventricular mass index (LVMi) and higher proportion of BAV compared patients without LGE. In addition, the proportion of moderate and severe AI patients was significantly higher in BAV group than in non-BAV group (P=0.009). (3) The consistency of CMR and TTE in evaluating the severity of AI patients: the agreement between TTE and CMR regarding AI severity was satisfactory (kappa value was 0.624, 95%CI 0.402-0.831, P<0.001). (4) The linear regression analysis demonstrated a negative correlation between LVEF and LGE% in BAV and non-BAV group (P<0.001). The multivariate logistic regression analysis showed that the presence of BAV was an independent risk factor of left ventricucar fibrosis (OR=5.050, 95%CI 1.220-20.908, P=0.025) after adjustment for LVEF, hypertension, LVEDVi and LVMi. Conclusion: Multi-parametric CMR provides a satisfactory noninvasive tool for estimation of myocardial fibrosis and ventricular remodeling in patients with AI, and BAV is an independent risk factor for myocardial fibrosis in patients with AI.

[Clinical and cardiac magnetic resonance features of apical hypertrophic cardiomyopathy patients complicating with left ventricular apical aneurysm]

Objective: To evaluate the clinical and cardiac magnetic resonance (CMR) features of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA). Methods: CMR confirmed 25 ApHCM patients complicating with LVAA from January 2010 to December 2017 in Fuwai hospital were included in this study, and the baseline clinical data and CMR characteristics were retrospectively analyzed. There were 14 pure ApHCM (hypertrophy limited at the apical segments) complicating with LVAA patients and 11 mixed ApHCM (predominantly apical hypertrophy along with thickening of contiguous non-apical left ventricular region) with LVAA patients. Results: In this patient cohort,age of 84% (21/25) patients ranged between 20-70 years old, and 68% (17/25) were male. There were 68% (17/25) patients with complaint of chest distress symptom, 56% (14/25) with complaint of chest pain, 32% (8/25) with complaint of palpitation,16% (4/25) with complaint of dyspnea, and 12% (3/25) presented as syncope. ST-T segment changes of electrocardiogram were observed in all patients, and giant negative T waves were detected in 80% patients (20/25). The rate of missed diagnosis by echocardiography for detecting ApHCM and LVAA was 16% (4/25) and 68% (17/25), respectively. CMR showed discrete thin-walled dyskinetic or akinetic segment of the most distal portion of the left ventricular chamber in ApHCM patients with LVAA. Transmural late gadolinium enhancement of the aneurysmal rim was detected in 76% (19/25) patients, and the maximum transverse dimension of aneurysm was bigger in patients with transmural late gadolinium enhancement than in patients without transmural late gadolinium enhancement ((22.0±10.8)mm vs. (11.7±4.0) mm, P=0.033). Conclusion: ApHCM with LVAA patients have distinct cardiac clinical features, and CMR is the most useful tool for the accurate and objective evaluation of this disease.

In vitro inhibition of porcine reproductive and respiratory syndrome virus replication by short antisense oligonucleotides with locked nucleic acid modification

Background

Porcine reproductive and respiratory syndrome virus (PRRSV) causes porcine reproductive and respiratory syndrome (PRRS), which is currently insufficiently controlled. From a previous small-scale screen we identified an effective DNA-based short antisense oligonucleotide (AS-ON) targeting viral NSP9, which could inhibit PRRSV replication in both Marc-145 cells and pulmonary alveolar macrophages (PAMs). The objective of this study was to explore the strategy of incorporating locked nucleic acids (LNAs) to achieve better inhibition of PRRSV replication in vitro.

Methods

The effective DNA-based AS-ON (YN8) was modified with LNAs at both ends as gap-mer (LNA-YN8-A) or as mix-mer (LNA-YN8-B). Marc-145 cells or PAMs were infected with PRRSV and subsequently transfected.

Results

Compared with the DNA-based YN8 control, the two AS-ONs modified with LNAs were found to be significantly more effective in decreasing the cytopathic effect (CPE) induced by PRRSV and thus in maintaining cell viability. LNA modifications conferred longer lifetimes to the AS-ON in the cell culture model. Viral ORF7 levels were more significantly reduced at both RNA and protein levels as shown by quantitative PCR, western blot and indirect immunofluorescence staining. Moreover, transfection with LNA modified AS-ON reduced the PRRSV titer by 10-fold compared with the YN8 control.

Conclusion

Taken together, incorporation of LNA into AS-ON technology holds higher therapeutic promise for PRRS control.

Myocardial late gadolinium enhancement: a head-to-head comparison of motion-corrected balanced steady-state free precession with segmented turbo fast low angle shot

AIM

To evaluate the image quality and diagnostic agreement with a head-to-head comparison of late gadolinium enhancement (LGE) images acquired by the motion-corrected (MOCO) balanced steady-state free precession (bSSFP) phase sensitivity inversion recovery (PSIR) and conventional segmented fast low angle shot (FLASH) PSIR methods^15,16 in a patient cohort with a wide spectrum of cardiovascular disease.

MATERIALS AND METHODS

In 59 consecutive patients, signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs) of the normal myocardium (NM), LGE, and blood pool (BP) were pair-wise compared between the two different sequences. A further semi-qualitative score system (graded 1 -4) was used to compare the overall image quality (OIQ). The diagnostic agreement of the two techniques were evaluated by both transmural severity and absolutely quantitative size of LGE.

RESULTS

The SNRs of the NM, LGE, and BP of MOCO bSSFP were 4.8±3.4, 53.6±35.6 and 43.2±29.3, compared with 3.9±3.6 (p=0.126), 27.7±18.5 (p<0.001) and 24.3±13.4 (p<0.001) of FLASH LGE, respectively. The CNRs of LGE to NM, LGE to BP, and BP to NM were 48.3±33.1 versus 23.8±16.7 (p<0.001), 6.5±21.6 versus 3.8±10.8 (p<0.001), and 38.3±27.2 versus 20.3±10.7 (p=0.448), respectively. The OIQ of MOCO bSSFP was higher than that of segmented FLASH (median 4 versus median 3, p<0.001). For quantification of LGE size, there is good agreement and high correlation (r=0.992, p<0.001) between the two methods.

CONCLUSIONS

MOCO bSSFP is a feasible, robust sequence for LGE imaging, especially for patients with arrhythmia and those incapable of breath-holding due to severe heart failure.

RACK1 is indispensable for porcine reproductive and respiratory syndrome virus replication and NF-κB activation in Marc-145 cells

Porcine reproductive and respiratory syndrome virus (PRRSV) causes porcine reproductive and respiratory syndrome (PRRS), which is currently insufficiently controlled. RACK1 (receptor of activated protein C kinase 1) was first identified as a receptor for protein kinase C, with increasing evidence showing that the functionally conserved RACK1 plays important roles in cancer development, NF-κB activation and various virus infections. However, the roles of RACK1 during PRRSV infection in Marc-145 cells have not been described yet. Here we demonstrated that infection of Marc-145 cells with the highly pathogenic PRRSV strain YN-1 from our lab led to activation of NF-κB and upregulation of RACK1 expression. The siRNA knockdown of RACK1 inhibited PRRSV replication in Marc-145 cells, abrogated NF-κB activation induced by PRRSV infection and reduced the viral titer. Furthermore, knockdown of RACK1 could inhibit an ongoing PRRSV infection. We found that RACK1 is highly conserved across different species based on the phylogenetic analysis of mRNA and deduced amino acid sequences. Taken together, RACK1 plays an indispensable role for PRRSV replication in Marc-145 cells and NF-κB activation. The results would advance our further understanding of the molecular mechanisms underlying PRRSV infection in swine and indicate RACK1 as a promising potential therapeutic target.

Volatile organic compounds emitted by filamentous fungi isolated from flooded homes after Hurricane Sandy show toxicity in a Drosophila bioassay

Superstorm Sandy provided an opportunity to study filamentous fungi (molds) associated with winter storm damage. We collected 36 morphologically distinct fungal isolates from flooded buildings. By combining traditional morphological and cultural characters with an analysis of ITS sequences (the fungal DNA barcode), we identified 24 fungal species that belong to eight genera: Penicillium (11 species), Fusarium (four species), Aspergillus (three species), Trichoderma (two species), and one species each of Metarhizium, Mucor, Pestalotiopsis, and Umbelopsis. Then, we used a Drosophila larval assay to assess possible toxicity of volatile organic compounds (VOCs) emitted by these molds. When cultured in a shared atmosphere with growing cultures of molds isolated after Hurricane Sandy, larval toxicity ranged from 15 to 80%. VOCs from Aspergillus niger 129B were the most toxic yielding 80% mortality to Drosophila after 12 days. The VOCs from Trichoderma longibrachiatum 117, Mucor racemosus 138a, and Metarhizium anisopliae 124 were relatively non-toxigenic. A preliminary analysis of VOCs was conducted using solid-phase microextraction-gas chromatography-mass spectrometry from two of the most toxic, two of the least toxic, and two species of intermediate toxicity. The more toxic molds produced higher concentrations of 1-octen-3-ol, 3-octanone, 3-octanol, 2-octen-1-ol, and 2-nonanone; while the less toxic molds produced more 3-methyl-1-butanol and 2-methyl-1-propanol, or an overall lower amount of volatiles. Our data support the hypothesis that at certain concentrations, some VOCs emitted by indoor molds are toxigenic.

Effect of selective serotonin reuptake inhibitors on expression of 5-HT1AR and neurotransmitters in rats with vascular dementia

5-hydroxytryptamine receptor 1A (5-HT1AR) is closely associated with cognitive functions. Selective serotonin reuptake inhibitors (SSRIs) can protect individuals from brain damage following ischemia/hypoxia. To investigate the function of SSRIs in vascular dementia (VD), we established a rat model of VD, and observed the effect of SSRIs on the expression of 5-HT1AR mRNA and neurotransmitters. Male SD rats (6 months) were randomly assigned into sham, model, and SSRI groups (N = 30). VD was achieved by permanent ligation of the bilateral common carotid artery. Escitalopram, a highly selective 5-HT reabsorption inhibitor, was ip injected into the rats for three consecutive weeks. The Morris water-maze was used to test learning and memory. H&E staining for neuronal injury was conducted on cortical and hippocampal tissues. HPLC was used to determine the levels of dopamine (DA), 5-HT, and norepinephrine (NE). RT-PCR was used to determine expression of 5-HT1AR mRNA. As compared to control rats, model animals demonstrated elongated escape latency, lower platform crossing times, and significant injuries to hippocampal CA1 neurons. This was accompanied by reductions in DA, 5-HT, and NE levels in hippocampal tissues, as well as reduced cortical 5-HT and decreased 5-HT1AR mRNA expression (P < 0.05). Escitalopram treatments reduced escape latency, elevated platform crossing times, improved CA1 neuronal damage, increased DA and 5-HT levels in hippocampal and cortical neurons, as well as elevated expression of 5-HT1AR mRNA (P < 0.05). Therefore, SSRIs may improve cognitive dysfunction of VD rats, possibly by stimulating expression of neurotransmitters and protecting neurons.

Asymptotic Properties of a Mean-Field Model with a Continuous-State-Dependent Switching Process

This work is concerned with a class of mean-field models given by a switching diffusion with a continuous-state-dependent switching process. Focusing on asymptotic properties, the regularity or nonexplosiveness, Feller continuity, and strong Feller continuity are established by means of introducing certain auxiliary processes and by making use of the truncations. Based on these results, exponential ergodicity is obtained under the Foster–Lyapunov drift conditions. By virtue of the coupling methods, the strong ergodicity or uniform ergodicity in the sense of convergence in the variation norm is established for the mean-field model with a Markovian switching process. Besides this, several examples are presented for demonstration and illustration.

Countable-state-space Markov chains with two time scales and applications to queueing systems

Motivated by various applications in queueing systems, this work is devoted to continuous-time Markov chains with countable state spaces that involve both fast-time scale and slow-time scale with the aim of approximating the time-varying queueing systems by their quasistationary counterparts. Under smoothness conditions on the generators, asymptotic expansions of probability vectors and transition probability matrices are constructed. Uniform error bounds are obtained, and then sequences of occupation measures and their functionals are examined. Mean square error estimates of a sequence of occupation measures are obtained; a scaled sequence of functionals of occupation measures is shown to converge to a Gaussian process with zero mean. The representation of the variance of the limit process is also explicitly given. The results obtained are then applied to treat Mt/Mt/1 queues and Markov-modulated fluid buffer models.

Discrete-time singularly perturbed Markov chains: aggregation, occupation measures, and switching diffusion limit

This work is devoted to asymptotic properties of singularly perturbed Markov chains in discrete time. The motivation stems from applications in discrete-time control and optimization problems, manufacturing and production planning, stochastic networks, and communication systems, in which finite-state Markov chains are used to model large-scale and complex systems. To reduce the complexity of the underlying system, the states in each recurrent class are aggregated into a single state. Although the aggregated process may not be Markovian, its continuous-time interpolation converges to a continuous-time Markov chain whose generator is a function determined by the invariant measures of the recurrent states. Sequences of occupation measures are defined. A mean square estimate on a sequence of unscaled occupation measures is obtained. Furthermore, it is proved that a suitably scaled sequence of occupation measures converges to a switching diffusion.

Convergence of a global stochastic optimization algorithm with partial step size restarting

This work develops a class of stochastic global optimization algorithms that are Kiefer-Wolfowitz (KW) type procedures with an added perturbing noise and partial step size restarting. The motivation stems from the use of KW-type procedures and Monte Carlo versions of simulated annealing algorithms in a wide range of applications. Using weak convergence approaches, our effort is directed to proving the convergence of the underlying algorithms under general noise processes.

Inhibition of porcine reproductive and respiratory syndrome virus replication in vitro using DNA-based short antisense oligonucleotides

BACKGROUND

Porcine reproductive and respiratory syndrome (PRRS) is caused by porcine reproductive and respiratory syndrome virus (PRRSV) and is an economically important disease in swine-producing areas. The objective of this study was to screen for effective antisense oligonucleotides (AS-ONs) which could inhibit PRRSV replication in MARC-145 cells and in pulmonary alveolar macrophages (PAM).

RESULTS

Nine short AS-ON sequences against the well-conserved regions of PRRSV (5'-UTR, NSP9, ORF5 and ORF7) were selected. When MARC-145 cells or PAM were infected with PRRSV followed by transfection with AS-ONs, four AS-ON sequences targeting 5'-UTR, ORF5 or NSP9 were found to be the most effective oligonucleotides in decreasing the cytopathic effect (CPE) induced by PRRSV infection. Quantitative PCR and indirect immunofluorescence staining confirmed that ORF7 levels were significantly reduced both at RNA and protein levels. The PRRSV titration data furthermore indicated that transfection with AS-ON YN8 could reduce the PRRSV titer by 1000-fold compared with controls.

CONCLUSION

The results presented here indicate that DNA-based antisense oligonucleotides can effectively inhibit PRRSV replication in MARC-145 cells and in PAM. Furthermore, comparing with the reported hit rates (approximately 10-30 %), we achieved a higher success rate (44 %). The strategy we took to design the antisense sequences might be applied to select AS-ONs that more efficiently reduce the expression of target genes.

Kelvin probe imaging of photo-injected electrons in metal oxide nanosheets from metal sulfide quantum dots under remote photochromic coloration

Metal oxide and quantum dot (QD) heterostructures have attracted considerable recent attention as materials for developing efficient solar cells, photocatalysts, and display devices, thus nanoscale imaging of trapped electrons in these heterostructures provides important insight for developing efficient devices. In the present study, Kelvin probe force microscopy (KPFM) of CdS quantum dot (QD)-grafted Cs4W11O36(2-) nanosheets was performed before and after visible-light irradiation. After visible-light excitation of the CdS QDs, the Cs4W11O36(2-) nanosheet surface exhibited a decreased work function in the vicinity of the junction with CdS QDs, even though the Cs4W11O36(2-) nanosheet did not absorb visible light. X-ray photoelectron spectroscopy revealed that W(5+) species were formed in the nanosheet after visible-light irradiation. These results demonstrated that excited electrons in the CdS QDs were injected and trapped in the Cs4W11O36(2-) nanosheet to form color centers. Further, the CdS QDs and Cs4W11O36(2-) nanosheet composite films exhibited efficient remote photochromic coloration, which was attributed to the quantum nanostructure of the film. Notably, the responsive wavelength of the material is tunable by adjusting the size of QDs, and the decoloration rate is highly efficient, as the required length for trapped electrons to diffuse into the nanosheet surface is very short owing to its nanoscale thickness. The unique properties of this photochromic device make it suitable for display or memory applications. In addition, the methodology described in the present study for nanoscale imaging is expected to aid in the understanding of electron transport and trapping processes in metal oxide and metal chalcogenide heterostructure, which are crucial phenomena in QD-based solar cells and/or photocatalytic water-splitting systems.

Expression of G protein αq Subunit is Decreased in Lymphocytes from Patients with Rheumatoid Arthritis and is Correlated with Disease Activity

Gαq, the alpha subunit of Gq, a member of the Gq/11 sub-family, was reported to inhibit phosphatidylinositol-3-Kinase (PI3K) activation and prevent the activation of Akt. Previous studies demonstrated that mice losing Gαq in their immune system could spontaneously develop inflammatory arthritis. In this study, we showed that the Gαq expressions at mRNA and protein levels in the peripheral blood lymphocytes (PBLs) from patients with rheumatoid arthritis (RA) were significantly decreased in comparison of which in healthy individuals. The expression levels of Gαq mRNA in PBLs from patients with RA were correlated with RA disease activity (DAS28), anti-cyclic citrullinated protein antibodies, C-reactive protein and rheumatoid factor. We also demonstrated that Gαq controlled the apoptosis of RA PBLs through regulating the activity of Mcl-1 and caspase-3. These data suggested that Gαq might be involved in the pathogenesis of RA by regulating PBLs apoptosis.

Adenoviral vector-mediated overexpression of osteoprotegerin accelerates osteointegration of titanium implants in ovariectomized rats

This study investigated the efficacy of human osteoprotegerin (hOPG) transgene to accelerate osteointegration of titanium implant in ovariectomized (OVX) rats. Bone marrow stromal cells transduced with Ad-hOPG-EGFP could sustainedly express hOPG. Osteoclast precursor RAW264.7 cells treated by the hOPG were examined by tartrate-resistant acid phosphatase (TRAP) staining and bone slice resorption assay. The results showed differentiation and function of osteoclasts were significantly suppressed by hOPG in vitro. Ad-hOPG-EGFP was locally administered to the bone defect prior to implant placement in OVX and sham rats. After 3, 7, 28 days of implantation, the femurs were harvested for molecular and histological analyses. Successful transgene expression was confirmed by western blot and cryosectioning. A significant reduction in TRAP+ numbers was detected in Ad-hOPG-EGFP group. Real-time reverse transcriptase-PCR examination revealed that hOPG transgene markedly diminished the expression of cathepsin K and receptor activator for nuclear factor-κ B ligand in vivo. The transgene hOPG modification revealed a marked increasing osteointegration and restored implant stability in OVX rats (P<0.01), compared with the control groups (Ad-EGFP or sterilized phosphate-buffered saline) 28 days after implantation. In conclusion, hOPG via direct adenovirus-mediated gene transfer could accelerate osteointegration of titanium implants in OVX rats. Osteoprotegerin gene therapy may be an effective strategy to osteointegration of implants under osteoporotic conditions.