Cardiac T1 and T2 Mapping Showed Myocardial Involvement in Recovered COVID-19 Patients Initially Considered Devoid of Cardiac Damage.

BACKGROUND: Myocardial injury has been found using magnetic resonance imaging in recovered coronavirus disease 2019 (COVID-19) patients unselected or with ongoing cardiac symptoms. PURPOSE: To evaluate for the presence of myocardial involvement in recovered COVID-19 patients without cardiovascular symptoms and abnormal serologic markers during hospitalization. STUDY TYPE: Prospective. POPULATION: Twenty-one recovered COVID-19 patients and 20 healthy controls (HC). FIELD STRENGTH/SEQUENCE: 3.0 T, cine, T2-weighted imaging, T1 mapping, and T2 mapping. ASSESSMENT: Cardiac ventricular function includes end-diastolic volume, end-systolic volume, stroke volume, cardiac output, left ventricle (LV) mass, and ejection fraction (EF) of LV and right ventricle (RV), and segmental myocardial T1 and T2 values were measured. STATISTICAL TESTS: Student's t-test, univariate general linear model test, and chi-square test were used for analyses between two groups. Ordinary one-way analyses of variance or Kruskal-Wallis H test were used for analyses between three groups, followed by post-hoc analyses. RESULTS: Fifteen (71.43%) COVID-19 patients had abnormal magnetic resonance findings, including raised myocardial native T1 (5, 23.81%) and T2 values (10, 47.62%), decreased LVEF (1, 4.76%), and RVEF (2, 9.52%). The segmental myocardial T2 value of COVID-19 patients (49.20 [46.1, 54.6] msec) was significantly higher than HC (48.3 [45.2, 51.7] msec) (P < 0.001), while the myocardial native T1 value showed no significant difference between COVID-19 patients and HC. The myocardial T2 value of serious COVID-19 patients (52.5 [48.1, 57.1] msec) was significantly higher than unserious COVID-19 patients (48.8 [45.9, 53.8] msec) and HC (48.3 [45.2, 51.7]) (P < 0.001). COVID-19 patients with abnormally elevated D-dimer, C-reactive protein, or lymphopenia showed higher myocardial T2 values than without (all P < 0.05). DATA CONCLUSION: Cardiac involvement was observed in recovered COVID-19 patients with no preexisting cardiovascular disease, no cardiovascular symptoms, and elevated serologic markers of myocardial injury during the whole course of COVID-19. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 5.

Young and early-onset dilated cardiomyopathy with malignant ventricular arrhythmia and sudden cardiac death induced by the heterozygous LDB3, MYH6, and SYNE1 missense mutations.

BACKGROUND: The whole exome sequencing (WES) with targeted gene analysis is an effective diagnostic tool for cardiomyopathy. The early-onset sudden cardiac death (SCD) was commonly associated with dilated cardiomyopathy (DCM) induced by pathogenic genetic mutations. METHODS: In a Chinese Han family, the patient of 24 years old occurred with early-onset and DCM and died of SCD associated with ICD storms induced by repetitive ventricular tachycardia/fibrillation (VT/F). Genomic DNA samples of peripheral blood were conducted for WES and Sanger sequence. Then, we performed bioinformatics analysis for 200 genes susceptible to cardiomyopathies and arrhythmias. Further, we analyzed how the potential pathogenic mutations affecting the secondary structure, hydrophobicity, and phosphorylation of amino acids, protein properties, and their joint pathogenicity by ProtParam, SOPMA, and ORVAL algorisms. The protein-protein interaction was analyzed by STRING algorism. RESULTS: The mutations of LDB3 p.M456R, MYH6 p.S180Y, and SYNE1 p.S4607F were identified as "Damaging/Deleterious." The SYNE1 (p.S4607F) increased one of alpha helix and decreased one of beta sheet. The LDB3 (p.M456R) reduced one of beta sheet and increased one of beta turn. The MYH6 (p.S180Y) decreased two of beta sheets and four of beta turns, but significantly increased twelve coils. The hydrophobicity of amino acid residues and their adjacent sequences were decreased by LDB3 (p.M456R) and MYH6 (p.S180Y), and significantly increased by SYNE1 (p.S4607F). The mutations of LDB3 (p.M456R), SYNE1 (p.S4607F), and MYH6 (p.S180Y) resulted in the phosphorylation changes of the corresponding amino acid sites or the nearby amino acid sites. The pairwise combinations of LDB3, MYH6, and SYNE1 mutations have the high probability of causing disease, especially the highest probability for SYNE1 and LDB3 mutations. There was obviously indirect interaction of the proteins encoded by SYNE1, LDB3, and MYH6. CONCLUSIONS: The multiple heterozygous mutations of SYNE1, LDB3, and MYH6 may be associated with young and early-onset of DCM and SCD.

Indicators and prediction models for the severity of Covid-19.

OBJECTIVES: Coronavirus disease 2019 (Covid-19) is outbreaking globally. We aimed to analyse the clinical characteristics, cardiac injury, electrocardiogram and computed tomography (CT) features of patients confirmed Covid-19 and explored the prediction models for the severity of Covid-19. METHODS: A retrospective and single-centre study enrolled 98 laboratory-confirmed Covid-19 patients. Clinical data, electrocardiogram and CT features were collected and analysed using Statistical Package for the Social Sciences software. RESULTS: There were 46 males and 52 females, with a median age of 44 years, categorised into three groups, including mild, moderate and severe/critical Covid-19. The rate of abnormal electrocardiograms in severe/critical group (79%) was significantly higher than that in the mild group (17%) (P = .027), which (r = 0.392, P = .005) positively related to the severity of Covid-19 (OR: 5.71, 95% CI: 0.45-3.04, P = .008). Age older than 60 years old, comorbidities, whether had symptoms on admission, fatigue, CT features, laboratory test results such as platelet count, lymphocyte cell count, eosinophil cell count, CD3+ cell count, CD4+ cell count, CD8+ cell count, the ratio of albumin/globulin decreased and D-dimer, C-reactive protein (CRP), B-type natriuretic peptide (BNP), cardiac troponin I (cTnI) elevated were the risk factors for the increased severity of Covid-19. The logistic model, adjusted by age, lobular involvement score and lymphocyte cell count, could be applied for assessing the severity of Covid-19 (AUC, 0.903; Sensitivity, 90.9%; Specificity, 78.1%). CONCLUSIONS: Age >60 years old, chronic comorbidities, lymphocytopoenia and lobular involvement score were associated with the Covid-19 severity. The inflammation induced by Covid-19 caused myocardial injury with elevated BNP and cTnI level and abnormal electrocardiograms.

Co-delivery of microRNA-21 antisense oligonucleotides and gemcitabine using nanomedicine for pancreatic cancer therapy.

Tumor metastasis occurs naturally in pancreatic cancer, and the efficacy of chemotherapy is usually poor. Precision medicine, combining downregulation of target genes with chemotherapy drugs, is expected to improve therapeutic effects. Therefore, we developed a combined therapy of microRNA-21 antisense oligonucleotides (ASO-miR-21) and gemcitabine (Gem) using a targeted co-delivery nanoparticle (NP) carrier and investigated the synergistic inhibitory effects on pancreatic cancer cells metastasis and growth. Polyethylene glycol-polyethylenimine-magnetic iron oxide NPs were used to co-deliver ASO-miR-21 and Gem. An anti-CD44v6 single-chain variable fragment (scFvCD44v6 ) was used to coat the particles to obtain active and targeted delivery. Our results showed that the downregulation of the oncogenic miR-21 by ASO resulted in upregulation of the tumor-suppressor genes PDCD4 and PTEN and the suppression of epithelial-mesenchymal transition, which inhibited the proliferation and induced the clonal formation, migration, and invasion of pancreatic cancer cells in vitro. The co-delivery of ASO-miR-21 and Gem induced more cell apoptosis and inhibited the growth of pancreatic cancer cells to a greater extent than single ASO-miR-21 or Gem treatment in vitro. In animal tests, more scFvCD44v6 -PEG-polyethylenimine/ASO-magnetic iron oxide NP/Gem accumulated at the tumor site than non-targeted NPs and induced a potent inhibition of tumor proliferation and metastasis. Magnetic resonance imaging was used to observed tumor homing of NPs. These results imply that the combination of miR-21 gene silencing and Gem therapy using an scFv-functionalized NP carrier exerted synergistic antitumor effects on pancreatic cancer cells, which is a promising strategy for pancreatic cancer therapy.

Value of severe liver iron overload for assessing heart iron levels in thalassemia major patients.

PURPOSE: The relationship between severe liver iron overload (LIO) and heart iron overload (HIO) in transfusion-dependent patients with thalassemia major (TM) is uncertain. Whether severe LIO can serve as an index for assessing heart iron deposition has vital clinical significance. Therefore, our aim is to determine if a close relationship exists between severe LIO and HIO. MATERIALS AND METHODS: We examined 110 TM patients who underwent T2* measurement in the liver and heart on a 1.5 Tesla MRI scanner. Various statistical analysis methods were used to assess the relationship. RESULTS: Most of these patients suffered from severe LIO (58.18%, liver T2* < 1.4 ms). Both Pearson's and Spearman's tests showed a significant correlation between liver T2* and heart T2* values (with a correlation coefficient of 0.408 and 0.550, respectively, both P < 0.0001). A nonlinear model, with the equation of Heart T2* = 37.974-17.684 / Liver T2*, was found to be the best model to indicate the relationship between liver T2* and heart T2*. Receiver operating characteristic (ROC) analysis showed the area under the ROC curve of liver T2* and serum ferritin for predicting HIO was 0.812 (95% confidence interval [CI]: 0.731-0.892; P < 0.0001) and 0.69 (95% CI: 0.585-0.795; P = 0.001), respectively. CONCLUSION: Our preliminary data suggest the existence of a close relationship between severe LIO and HIO. High liver iron levels appear to increase the risk of heart iron deposition. This further supports the concept of critical liver iron concentration, above which elevated heart iron is present. J. MAGN. RESON. IMAGING 2016;44:880-889.

MRI assessment of excess cardiac iron in thalassemia major: When to initiate?

BACKGROUND: To determine optimal initial age of cardiac iron screening with magnetic resonance imaging (MRI) T2* in patients with thalassemia major (TM). METHODS: We retrospectively reviewed black blood cardiac T2* assessments from 102 TM patients from the ages of 3 to 32 years. Cases of patients under and above 7 years old with detectable cardiac iron overload were analyzed separately. Associations between cardiac T2* and various factors, such as serum ferritin (SF), patient age and hepatic T2*, were assessed using either scatterplots or regression. Images were evaluated by two independent radiologists. RESULTS: With a T2* cut-off value of 20 ms, no patient under 5 years old showed cardiac iron overload. Three of 19 (15.8%) patients under 7 years of age had a cardiac T2* ≤ 20 ms (5.5 to 7 years) but none had ≤10 ms, while 35 of 83 (42.2%) patients above 7 years old had a cardiac T2* ≤ 20 ms (8 to 32 years) and 18 of them ≤10 ms. Cardiac T2* correlated weakly with serum ferritin and liver T2* (r = -0.39 and 0.41, respectively, both P < 0.001), but not with patient age (P > 0.05). CONCLUSION: Cardiac iron overload can occur in young TM patients, even as young as 5.5 years old. Assessment of cardiac iron with T2* might need to begin as early as 5 years old if suboptimal chelation therapy is administered.

pH-responsive nanoemulsions for controlled drug release.

Three ternary graft copolymers bearing polystyrene (PS), poly(ethylene glycol) methyl ether (MPEG), and poly(acrylic acid) (PAA) side chains were synthesized and characterized. At pH = 7.4, these copolymers stabilized doxorubicin (DOX)-containing benzyl benzoate (BBZ) nanoemulsion droplets in water and formed a compact polymer layer to inhibit DOX release. Upon lowering the solution pH to 5.0, the AA groups dissociated less and became less soluble. Moreover, the neutralized AA groups formed presumably H-bonded complexes with the EG units, reducing the solubility of the EG units. This dual action drastically shifted the hydrophilic and hydrophobic balance of the copolymer and caused the original stabilizing polymer layer to rupture and the nanoemulsion droplets to aggregate, releasing DOX. The rate and extent of DOX release could be increased by matching the numbers of PAA and MPEG chains per graft copolymer. In addition, these nanoemulsions were not toxic and entered human carcinoma cells, releasing DOX there. Thus, these nanoemulsions have potential as drug delivery vehicles.

A Meta-Path-Based Evaluation Method for Enterprise Credit Risk.

Nowadays, small and medium-sized enterprises (SMEs) have become an essential part of the national economy. With the increasing number of such enterprises, how to evaluate their credit risk becomes a hot issue. Unlike big enterprises with massive data to analyse, it is hard to find enough primary information of SMEs to assess their financial status, which makes the credit risk evaluation result less accurate. Limited by the lack of primary data, how to infer SMEs' credit risk from secondary data, such as information about their upstream, downstream, parent, and subsidiary enterprises, attracts big attention from industry and academy. Targeting on accurately evaluating the credit risk of the SME, in this study, we exploit the representative power of the information network on various kinds of SME entities and SME relationships to solve the problem. With that, a heterogeneous information network of SMEs is built to mine enterprise's secondary information. Furthermore, a novel feature named meta-path feature is proposed to measure the credit risk, which makes us able to evaluate the financial status of SMEs from various perspectives. Experiments show that our proposed meta-path feature is effective to identify SMEs with credit risks.

A Path-Based Feature Selection Algorithm for Enterprise Credit Risk Evaluation.

In recent years, there has been increasing interest in exploring diversified features to measure small and medium-sized enterprises (SMEs) credit risk. Path-based features, revealing logical connections between SMEs, are widely adopted as informative feature kinds for causal inference in credit risk evaluation. Since there may exist thousands of feature paths to the target enterprise, to evaluate its credit risk, how to select the most informative path-based features becomes a challenging problem. To solve the problem, in this paper, we propose a novel method of feature selection, considering both similarity and importance on features' structured semantics as the factors of informativeness. With this, the proposed method can effectively rank both conventional and path-based features together. Furthermore, to improve the efficiency of the method, a heuristic algorithm is proposed to fast search for the candidate features. Through extensive experiments, we show our method performs competitively with other state-of-the-art selection methods.

Identification of rare heterozygous linkage R965C-R1309H mutations in the pore-forming region of SCN5A gene associated with complex arrhythmia.

BACKGROUND: We examined the genetic background of a Chinese Han family in which some members presented with complex arrhythmias including sick sinus syndrome, progressive conduction block, atrial fibrillation, atrial standstill and Brugada syndrome. The possible underlying mechanism associated with the genetic mutation was explored. METHODS: Targeted capture sequencing was conducted in the probands in the coding and splicing regions of genes implicated in inherited arrhythmias. Stable cell lines overexpressing wild type (WT) or mutant SCN5A were generated in HEK293T cells. Whole-cell recording was performed to evaluate the functional changes in sodium channels. RESULTS: The rare heterozygous linkage mutations, SCN5A R965C and R1309H, were found in these patients with complex familial arrhythmias. Compared to WT, R965C or R1309H, the peak current of sodium channel was dramatically reduced in HEK293T cell with linkage R965C-R1309H mutation when testing potentials ranging from -45 to 15 mV. Notably, the maximum peak current of sodium channels with R1309H and linkage R965C-R1309H displayed significant decreases of 31.5% and 73.34%, respectively, compared to WT. Additionally, compared to R965C or R1309H alone, the linkage mutation R965C-R1309H demonstrated not only a more obvious depolarisation-shifted activation and hyperpolarisation-shifted inactivation, but also a more significant alteration in the time constant, V1/2 and the slope factor of activation and inactivation. CONCLUSIONS: The linkage mutation SCN5A R965C-R1309H led to a more dramatically reduced current density, as well as more significant depolarisation-shifted activation and hyperpolarisation-shifted inactivation in sodium channels than R965C or R1309H alone, which potentially explain this complex familial arrhythmia syndrome.

Overlap phenotypes of the left ventricular noncompaction and hypertrophic cardiomyopathy with complex arrhythmias and heart failure induced by the novel truncated DSC2 mutation.

BACKGROUND: The left ventricular noncompaction cardiomyopathy (LVNC) is a rare subtype of cardiomyopathy associated with a high risk of heart failure (HF), thromboembolism, arrhythmia, and sudden cardiac death. METHODS: The proband with overlap phenotypes of LVNC and hypertrophic cardiomyopathy (HCM) complicates atrial fibrillation (AF), ventricular tachycardia (VT), and HF due to the diffuse myocardial lesion, which were diagnosed by electrocardiogram, echocardiogram and cardiac magnetic resonance imaging. Peripheral blood was collected from the proband and his relatives. DNA was extracted from the peripheral blood of proband for high-throughput target capture sequencing. The Sanger sequence verified the variants. The protein was extracted from the skin of the proband and healthy volunteer. The expression difference of desmocollin2 was detected by Western blot. RESULTS: The novel heterozygous truncated mutation (p.K47Rfs*2) of the DSC2 gene encoding an important component of desmosomes was detected by targeted capture sequencing. The western blots showed that the expressing level of functional desmocollin2 protein (~ 94kd) was lower in the proband than that in the healthy volunteer, indicating that DSC2 p.K47Rfs*2 obviously reduced the functional desmocollin2 protein expression in the proband. CONCLUSION: The heterozygous DSC2 p.K47Rfs*2 remarkably and abnormally reduced the functional desmocollin2 expression, which may potentially induce the overlap phenotypes of LVNC and HCM, complicating AF, VT, and HF.

MMP1/PAR1/SP/NK1R paracrine loop modulates early perineural invasion of pancreatic cancer cells.

The molecular mechanism of perineural invasion (PNI) is unclear, and insufficient detection during early-stage PNI in vivo hampers its investigation. We aimed to identify a cytokine paracrine loop between pancreatic ductal adenocarcinoma (PDAC) cells and nerves and established a noninvasive method to monitor PNI in vivo. Methods: A Matrigel/ dorsal root ganglia (DRG) system was used to observe PNI in vitro, and a murine sciatic nerve invasion model was established to examine PNI in vivo. PNI was assessed by MRI with iron oxide nanoparticle labeling. We searched publicly available datasets as well as obtained PDAC tissues from 30 patients to examine MMP1 expression in human tumor and non-tumor tissues. Results: Our results showed that matrix metalloproteinase-1 (MMP1) activated AKT and induced protease-activated receptor-1 (PAR1)-expressing DRG to release substance P (SP), which, in turn, activated neurokinin 1 receptor (NK1R)-expressing PDAC cells and enhanced cellular migration, invasion, and PNI via SP/NK1R/ERK. In animals, hind limb paralysis and a decreased hind paw width were observed approximately 20 days after inoculation of cancer cells in the perineurium. MMP1 silencing with shRNA or treatment with either a PAR1 or an NK1R antagonist inhibited PNI. MRI detected PNI as early as 10 days after implantation of PDAC cells. PNI also induced PDAC liver metastasis. Bioinformatic analyses and pathological studies on patient tissues corroborated the clinical relevance of these findings. Conclusion: In this study, we provided evidence that the MMP1/PAR1/SP/NK1R paracrine loop contributes to PNI during the early stage of primary tumor formation. Furthermore, we established a sensitive and non-invasive method to detect nerve invasion using iron oxide nanoparticles and MRI.

Magnetic resonance imaging-visible and pH-sensitive polymeric micelles for tumor targeted drug delivery.

Folate-functionalized copolymers of poly(ethylene glycol) and 2-(diisopropylamino) ethylamine grafted poly(L-aspartic acid) are synthesized. The copolymers can self-assemble into nanoscaled micelles encapsulated with hydrophobic model drug Fluorescein Diacetate (FDA) and MRI diagnostic agents superparamagnetic iron oxide nanoparticles (SPIONs) in aqueous solution of a neutral pH resembling physiological environment, whereas disassemble in acidic endosomal/lysosomal compartments of tumor cells to achieve rapid drug release. In vitro drug release study showed that FDA release from the pH-sensitive micelles was much faster at pH 5.0 than at pH 7.4. Clustering of SPIONs inside the hydrophobic core of the micelles resulted in a high spin-spin (T2,) relaxivity for a super MRI sensitivity. Cell culture studies showed that the FDA-SPION-loaded micelles were effectively internalized by human hepatic Bel-7402 cancer cells following a folate receptor-mediated targeting mechanism, and then FDA was rapidly release from micelles inside lysosomal compartments. Micelles encapsulating paclitaxel (PTX) studies showed it can induce more effective cell toxicity. This study demonstrated the great potential of the pH-sensitive micelles as an effective multifunctional nanomedician platform for cancer therapy due to their active tumor targeting, pH-triggered drug release and ultrasensitive MRI responsiveness.

Renal hemodynamic changes with aging: a preliminary study using CT perfusion in the healthy elderly.

OBJECTIVE: To investigate renal blood flow perfusion parameter changes associated with aging using multislice spiral computed tomography (CT). METHODS: This prospective study was approved by the institute's ethics committee for clinical study and written informed consent was obtained from all subjects. Forty-two consecutive patients who underwent abdominal CT without obvious renal abnormality at plain scanning were enrolled in this study. The renal perfusion scan was carried out using 16-slice spiral CT. The Pearson correlation coefficient was used to examine the correlation between perfusion parameter changes with aging. RESULTS: In both the cortex and medulla, blood flow (BF) and blood volume (BV) were negatively correlated with age, while time-to-peak (TTP) value and mean transit time (MTT) showed a positive correlation with age. Changes in BF, TTP, and MTT were found to have a statistically significant correlation with age in both the cortex and medulla, while the correlation between BV and age showed no statistical significance. CONCLUSION: It is feasible to assess renal hemodynamics changes with aging in the elderly using the current clinically available CT perfusion imaging technology in vivo. It may be helpful in the management of aged patients to familiarize with the renal hemodynamics changes in clinical work-up.