Lipid nanoparticles allow efficient and harmless ex vivo gene editing of human hematopoietic cells.

Ex vivo gene editing in T cells and hematopoietic stem/progenitor cells (HSPCs) holds promise for treating diseases. Gene editing encompasses the delivery of a programmable editor RNA or ribonucleoprotein, often achieved ex vivo via electroporation, and when aiming for homology-driven correction of a DNA template, often provided by viral vectors together with a nuclease editor. Although HSPCs activate a robust p53-dependent DNA damage response upon nuclease-based editing, the responses triggered in T cells remain poorly characterized. Here, we performed comprehensive multiomics analyses and found that electroporation is the main culprit of cytotoxicity in T cells, causing death and cell cycle delay, perturbing metabolism, and inducing an inflammatory response. Nuclease RNA delivery using lipid nanoparticles (LNPs) nearly abolished cell death and ameliorated cell growth, improving tolerance to the procedure and yielding a higher number of edited cells compared with using electroporation. Transient transcriptomic changes upon LNP treatment were mostly caused by cellular loading with exogenous cholesterol, whose potentially detrimental impact could be overcome by limiting exposure. Notably, LNP-based HSPC editing dampened p53 pathway induction and supported higher clonogenic activity and similar or higher reconstitution by long-term repopulating HSPCs compared with electroporation, reaching comparable editing efficiencies. Overall, LNPs may allow efficient and harmless ex vivo gene editing in hematopoietic cells for the treatment of human diseases.

Tolerogenic IL-10-engineered dendritic cell-based therapy to restore antigen-specific tolerance in T cell mediated diseases.

Tolerogenic dendritic cells play a critical role in promoting antigen-specific tolerance via dampening of T cell responses, induction of pathogenic T cell exhaustion and antigen-specific regulatory T cells. Here we efficiently generate tolerogenic dendritic cells by genetic engineering of monocytes with lentiviral vectors co-encoding for immunodominant antigen-derived peptides and IL-10. These transduced dendritic cells (designated DCIL-10/Ag) secrete IL-10 and efficiently downregulate antigen-specific CD4+ and CD8+ T cell responses from healthy subjects and celiac disease patients in vitro. In addition, DCIL-10/Ag induce antigen-specific CD49b+LAG-3+ T cells, which display the T regulatory type 1 (Tr1) cell gene signature. Administration of DCIL-10/Ag resulted in the induction of antigen-specific Tr1 cells in chimeric transplanted mice and the prevention of type 1 diabetes in pre-clinical disease models. Subsequent transfer of these antigen-specific T cells completely prevented type 1 diabetes development. Collectively these data indicate that DCIL-10/Ag represent a platform to induce stable antigen-specific tolerance to control T-cell mediated diseases.

Cardiac computed tomography: from anatomy to function.

Ischaemic heart disease (IHD) is one of the world's leading causes of morbidity and mortality. Likewise, the diagnosis and risk stratification of patients with coronary artery disease (CAD) have always been based on the detection of the presence and extent of ischaemia by physical or pharmacological stress tests with or without the aid of imaging methods (e.g. exercise stress, test, stress echocardiography, single-photon emission computed tomography, or stress cardiac magnetic resonance). These methods show high performance to assess obstructive CAD, whilst they do not show accurate power to detect non-obstructive CAD. The introduction into clinical practice of coronary computed tomography angiography, the only non-invasive method capable of analyzing the coronary anatomy, allowed to add a crucial piece in the puzzle of the assessment of patients with suspected or chronic IHD. The current review evaluates the technical aspects and clinical experience of coronary computed tomography in the evaluation of atherosclerotic burden with a special focus about the new emerging application such as functional relevance of CAD with fractional flow reserve computed tomography (CT)-derived (FFRct), stress CT perfusion, and imaging inflammatory makers discussing the strength and weakness of each approach.

Diagnostic performance of deep learning algorithm for analysis of computed tomography myocardial perfusion.

PURPOSE: To evaluate the diagnostic accuracy of a deep learning (DL) algorithm predicting hemodynamically significant coronary artery disease (CAD) by using a rest dataset of myocardial computed tomography perfusion (CTP) as compared to invasive evaluation. METHODS: One hundred and twelve consecutive symptomatic patients scheduled for clinically indicated invasive coronary angiography (ICA) underwent CCTA plus static stress CTP and ICA with invasive fractional flow reserve (FFR) for stenoses ranging between 30 and 80%. Subsequently, a DL algorithm for the prediction of significant CAD by using the rest dataset (CTP-DLrest) and stress dataset (CTP-DLstress) was developed. The diagnostic accuracy for identification of significant CAD using CCTA, CCTA + CTP stress, CCTA + CTP-DLrest, and CCTA + CTP-DLstress was measured and compared. The time of analysis for CTP stress, CTP-DLrest, and CTP-DLStress was recorded. RESULTS: Patient-specific sensitivity, specificity, NPV, PPV, accuracy, and area under the curve (AUC) of CCTA alone and CCTA + CTPStress were 100%, 33%, 100%, 54%, 63%, 67% and 86%, 89%, 89%, 86%, 88%, 87%, respectively. Patient-specific sensitivity, specificity, NPV, PPV, accuracy, and AUC of CCTA + DLrest and CCTA + DLstress were 100%, 72%, 100%, 74%, 84%, 96% and 93%, 83%, 94%, 81%, 88%, 98%, respectively. All CCTA + CTP stress, CCTA + CTP-DLRest, and CCTA + CTP-DLStress significantly improved detection of hemodynamically significant CAD compared to CCTA alone (p < 0.01). Time of CTP-DL was significantly lower as compared to human analysis (39.2 ± 3.2 vs. 379.6 ± 68.0 s, p < 0.001). CONCLUSION: Evaluation of myocardial ischemia using a DL approach on rest CTP datasets is feasible and accurate. This approach may be a useful gatekeeper prior to CTP stress..

Computed tomography predictors of structural valve degeneration in patients undergoing transcatheter aortic valve implantation with balloon-expandable prostheses.

OBJECTIVES: Computed tomography (CT) provides excellent anatomy assessment of the aortic annulus (AoA) and is utilized for pre-procedural planning of transcatheter aortic valve implantation (TAVI). We sought to investigate if geometrical characteristics of the AoA determined by CT may represent predictors of structural valve degeneration (SVD) in patients undergoing TAVI with balloon-expandable valves. METHODS: This is a retrospective study on 124 consecutive patients (mean age: 79 ± 7 years; female: 61%) undergoing balloon-expandable TAVI prospectively enrolled in a registry. AoA maximum diameter (Dmax), minimum diameter (Dmin), and area were assessed using pre-procedural CT. SVD was identified during follow-up with transthoracic echocardiography documenting structural prosthetic valve abnormalities with or without hemodynamic changes. RESULTS: The mean follow-up was 5.9 ± 1.7 years. SVD was found in 48 out of 124 patients (38%). AoA Dmax, Dmin, and area were significantly smaller in patients with SVD compared to patients without SVD (25.6 ± 2.2 mm vs. 27.1 ± 2.8 mm, p = 0.012; 20.5 ± 2.1 mm vs. 21.8 ± 2.1 mm, p = 0.001 and 419 ± 77 mm2 vs. 467 ± 88 mm2, p = 0.002, respectively). At univariable analysis, female sex, BSA, 23-mm prosthetic valve size, Dmax < 27.1 mm, and a Dmin < 19.9 mm were associated with SVD, whereas at multivariable analysis, only Dmin < 19.9 mm (OR = 2.873, 95% CI: 1.191-6.929, p = 0.019) and female sex (OR = 2.659, 95% CI: 1.095-6.458, p = 0.031) were independent predictors of SVD. CONCLUSIONS: Female sex and AoA Dmin < 19.9 mm are associated with SVD in patients undergoing TAVI with balloon-expandable valves. When implanting large prostheses in order to avoid paraprosthetic regurgitation, caution should be observed due to the risk of excessive stretching of the AoA Dmin, which may play a role in SVD. KEY POINTS: • Long-term durability is a concern for transcatheter aortic valve bioprosthesis. • CT provides an excellent assessment of the aortic annulus's geometrical characteristics for prosthesis sizing before transcatheter aortic valve implantation (TAVI). • Female sex and a small minimum aortic annulus diameter measured with CT are independent predictors of structural valve degeneration in patients undergoing TAVI with balloon-expandable valves.

Plaque assessment by coronary CT angiography may predict cardiac events in high risk and very high risk diabetic patients: A long-term follow-up study.

BACKGROUND AND AIMS: The aim of the present study is to evaluate whether advanced coronary atherosclerosis analysis by CCTA may improve prognostic stratification among diabetic patients at high cardiovascular risk (CV risk). METHODS AND RESULTS: The study population consisted of 265 consecutive diabetic patients at high CV risk who underwent CCTA for suspected CAD between January 2011 and December 2016. For every patients both traditional and advanced, qualitative and quantitative coronary plaque analysis were performed. The occurrence of cardiac death, ACS, and non-urgent revascularization were recorded at follow-up. Among the 265 patients enrolled, 21 were lost to follow-up, whereas 244 (92%) had a complete follow-up (mean 45 ± 22 months) and were classified at high (n = 67) or very high cardiovascular risk (n = 177), according to ESC Guidelines. A total of 63 events were recorded (3 Cardiac Death, 3 NSTEMI, 8 unstable angina, 36 late non-urgent revascularization and 13 non-cardiac death) in 57 different patients. Elevated fibro-fatty plaque volume was the only predictor of events over age, gender and traditional risk factor when ACS and MACE were considered as end-points [HR (95% CI) 6.01 (1.65-21.87), p = 0.006 and 3.46 (2.00-5.97); p < 0.001]. CONCLUSION: The present study confirms the prognostic role of advance coronary atherosclerosis evaluation beyond risk factors and stenosis severity, even in diabetics. Despite the very high cardiovascular risk of study population, a not negligible portion (23%) of patients exhibited totally normal coronaries.

Neonatal combination therapy improves some of the clinical manifestations in the Mucopolysaccharidosis type I murine model.

Mucopolysaccharidosis type I (MPS-I), a lysosomal storage disorder caused by a deficiency of alpha-L-iduronidase enzyme, results in the progressive accumulation of glycosaminoglycans and consequent multiorgan dysfunction. Despite the effectiveness of hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) in correcting clinical manifestations related to visceral organs, complete improvement of musculoskeletal and neurocognitive defects remains an unmet challenge and provides an impact on patients' quality of life. We tested the therapeutic efficacy of combining HSCT and ERT in the neonatal period. Using a mouse model of MPS-I, we demonstrated that the combination therapy improved clinical manifestations in organs usually refractory to current treatment. Moreover, combination with HSCT prevented the production of anti-IDUA antibodies that negatively impact ERT efficacy. The added benefits of combining both treatments also resulted in a reduction of skeletal anomalies and a trend towards decreased neuroinflammation and metabolic abnormalities. As currently there are limited therapeutic options for MPS-I patients, our findings suggest that the combination of HSCT and ERT during the neonatal period may provide a further step forward in the treatment of this rare disease.

A Morphological and Quantitative Analysis of Lung CT Scan in Patients With Acute Respiratory Distress Syndrome and in Cardiogenic Pulmonary Edema.

BACKGROUND: The acute respiratory distress syndrome (ARDS) and cardiogenic pulmonary edema (CPE) are both characterized by an increase in lung edema that can be measured by computed tomography (CT). The aim of this study was to compare possible differences between patients with ARDS and CPE in the morphologic pattern, the aeration, and the amount and distribution of edema within the lung. METHODS: Lung CT was performed at a mean positive end-expiratory pressure level of 5 cm H2O in both groups. The morphological evaluation was performed by two radiologists, while the quantitative evaluation was performed by a dedicated software. RESULTS: A total of 60 patients with ARDS (20 mild, 20 moderate, 20 severe) and 20 patients with CPE were enrolled. The ground-glass attenuation regions were similarly present among the groups, 8 (40%), 8 (40%), 14 (70%), and 10 (50%), while the airspace consolidations were significantly more present in ARDS. The lung gas volume was significantly lower in severe ARDS compared to CPE (830 [462] vs 1120 [832] mL). Moving from the nondependent to the dependent lung regions, the not inflated lung tissue significantly increased, while the well inflated tissue decreased (ρ = 0.96-1.00, P < .0001). Significant differences were found between ARDS and CPE mostly in dependent regions. In severe ARDS, the estimated edema was significantly higher, compared to CPE (757 [740] vs 532 [637] g). CONCLUSIONS: Both ARDS and CPE are characterized by a similar presence of ground-glass attenuation and different airspace consolidation regions. Acute respiratory distress syndrome has a higher amount of not inflated tissue and lower amount of well inflated tissue. However, the overall regional distribution is similar within the lung.

Targeting a Pre-existing Anti-transgene T Cell Response for Effective Gene Therapy of MPS-I in the Mouse Model of the Disease.

Mucopolysaccharidosis type I (MPS-I) is a severe genetic disease caused by a deficiency of the alpha-L-iduronidase (IDUA) enzyme. Ex vivo hematopoietic stem cell (HSC) gene therapy is a promising therapeutic approach for MPS-I, as demonstrated by preclinical studies performed in naive MPS-I mice. However, after enzyme replacement therapy (ERT), several MPS-I patients develop anti-IDUA immunity that may jeopardize ex vivo gene therapy efficacy. Here we treat MPS-I mice with an artificial immunization protocol to mimic the ERT effect in patients, and we demonstrate that IDUA-corrected HSC engraftment is impaired in pre-immunized animals by IDUA-specific CD8+ T cells spared by pre-transplant irradiation. Conversely, humoral anti-IDUA immunity does not impact on IDUA-corrected HSC engraftment. The inclusion of lympho-depleting agents in pre-transplant conditioning of pre-immunized hosts allowes rescue of IDUA-corrected HSC engraftment, which is proportional to CD8+ T cell eradication. Overall, these data demonstrate the relevance of pre-existing anti-transgene T cell immunity on ex vivo HSC gene therapy, and they suggest the application of tailored immune-depleting treatments, as well as a deeper immunological characterization of patients, to safeguard the therapeutic effects of ex vivo HSC gene therapy in immunocompetent hosts.

Modulation of immune responses in lentiviral vector-mediated gene transfer.

Lentiviral vectors (LV) are widely used vehicles for gene transfer and therapy in pre-clinical animal models and clinical trials with promising safety and efficacy results. However, host immune responses against vector- and/or transgene-derived antigens remain a major obstacle to the success and broad applicability of gene therapy. Here we review the innate and adaptive immunological barriers to successful gene therapy, both in the context of ex vivo and in vivo LV gene therapy, mostly concerning systemic LV delivery and discuss possible means to overcome them, including vector design and production and immune modulatory strategies.

Image quality and radiation dose of coronary CT angiography performed with whole-heart coverage CT scanner with intra-cycle motion correction algorithm in patients with atrial fibrillation.

OBJECTIVES: To evaluate image quality, coronary evaluability and radiation exposure of coronary CT angiography (CCTA) performed with whole-heart coverage cardiac-CT in patients with atrial fibrillation (AF). MATERIALS AND METHODS: We prospectively enrolled 164 patients with AF who underwent a clinically indicated CCTA with a 16-cm z-axis coverage scanner. In all patients CCTA was performed using prospective ECG-triggering with targeted RR interval. We evaluated image quality, coronary evaluability and effective dose (ED). Patients were divided in two subgroups based on heart rate (HR) during imaging. Group 1: 64 patients with low HR (<75 bpm), group 2: 100 patients with high HR (≥75 bpm). Written informed consent was obtained from all patients and the institutional ethics committee approved the study protocol. RESULTS: In a segment-based analysis, coronary evaluability was 98.4 % (2,577/2,620 segments) in the whole population, without significant differences between groups (1,013/1,024 (98.9 %) and 1,565/1,596 (98.1 %), for groups 1 and 2, respectively, p=0.15). Mean ED was similar in both groups (3.8±1.9 mSv and 3.9±2.1 mSv in groups 1 and 2, respectively, p=0.75) CONCLUSIONS: The whole-heart-coverage scanner could evaluate coronary arteries with high image quality and without increase in radiation exposure in AF patients, even in the high HR group. KEY POINTS: • Last-generation CT scanner improves coronary artery assessment in AF patients. • The new CT scanner enables low radiation exposure in AF patients. • Diagnostic ICA maybe avoided in AF patients with suspected CAD. • Whole-heart coverage CT scanner enables low radiation exposure in AF patients.

Atrial Fibrillation: Diagnostic Accuracy of Coronary CT Angiography Performed with a Whole-Heart 230-µm Spatial Resolution CT Scanner.

Purpose To assess image quality, interpretability, diagnostic accuracy, and radiation exposure of a computed tomography (CT) scanner with 16-cm coverage and 230-µm spatial resolution at coronary artery evaluation in patients with atrial fibrillation (AF) by using invasive coronary angiography (ICA) as the reference method and to compare the results with those obtained in patients with sinus rhythm (SR). Materials and Methods Written informed consent and institutional ethics committee approval were obtained. Between March 2015 and February 2016, 166 consecutive patients were prospectively enrolled (83 with AF, 83 with SR). They underwent ICA and coronary CT angiography performed with a whole-heart CT scanner. Image quality, coronary segment interpretability, effective dose (ED), and diagnostic accuracy were assessed at CT angiography and were compared with those attained with ICA. Diagnostic performance of the groups was compared with the pairwise McNemar test. Results Mean heart rate during scanning was 83 beats per minute ± 21 (standard deviation) in the AF group and 63 beats per minute ± 14 in the SR group (P < .01). Coronary interpretability was 98.5% in the AF group and 98.4% in the SR group (P = .96). In a segment-based analysis, sensitivity and specificity in the detection of coronary stenosis of more than 50% compared with detection of ICA were 96.4% and 98.7%, respectively, in the chronic AF group (P = .98) and 95.6% and 98.1%, respectively, in the SR group (P = .32). In a patient-based analysis, sensitivity and specificity were 95.2% and 97.6%, respectively, in the chronic AF group (P = .95) and 97.8% and 94.7%, respectively, in the SR group (P = .93). Conclusion Whole-heart CT enables evaluation of coronary arteries with high image quality, low radiation exposure, and high diagnostic accuracy in patients with chronic AF, with a diagnostic performance similar to that in patients with SR. © RSNA, 2017 Online supplemental material is available for this article.

Integrated all-optical MIMO demultiplexer for mode- and wavelength-division-multiplexed transmission.

A photonic integrated circuit performing simultaneous mode and wavelength demultiplexing for few-mode-fiber transmission is demonstrated for the first time. The circuit is realized on an InP-based technological platform; it can handle up to eight mode- and wavelength-division-multiplexed (MDM/WDM) channels and allows all-optical multiple-input-multiple-output processing to unscramble mode mixing generated by fiber propagation. A single arrayed waveguide grating is used to demultiplex the WDM channels carried by all the propagating modes, optimizing circuit complexity, chip area, and operational stability. Combined with an integrated wideband mode multiplexer the circuit is successfully exploited for the transmission of 10 Gbit/s on-off-keying non-return-to-zero channels with a residual cross talk of about -15 dB.

Impact of an intra-cycle motion correction algorithm on overall evaluability and diagnostic accuracy of computed tomography coronary angiography.

OBJECTIVES: The aim of this study was to evaluate the impact of a novel intra-cycle motion correction algorithm (MCA) on overall evaluability and diagnostic accuracy of cardiac computed tomography coronary angiography (CCT). METHODS: From a cohort of 900 consecutive patients referred for CCT for suspected coronary artery disease (CAD), we enrolled 160 (18 %) patients (mean age 65.3 ± 11.7 years, 101 male) with at least one coronary segment classified as non-evaluable for motion artefacts. The CCT data sets were evaluated using a standard reconstruction algorithm (SRA) and MCA and compared in terms of subjective image quality, evaluability and diagnostic accuracy. RESULTS: The mean heart rate during the examination was 68.3 ± 9.4 bpm. The MCA showed a higher Likert score (3.1 ± 0.9 vs. 2.5 ± 1.1, p < 0.001) and evaluability (94%vs.79 %, p < 0.001) than the SRA. In a 45-patient subgroup studied by clinically indicated invasive coronary angiography, specificity, positive predictive value and accuracy were higher in MCA vs. SRA in segment-based and vessel-based models, respectively (87%vs.73 %, 50%vs.34 %, 85%vs.73 %, p < 0.001 and 62%vs.28 %, 66%vs.51 % and 75%vs.57 %, p < 0.001). In a patient-based model, MCA showed higher accuracy vs. SCA (93%vs.76 %, p < 0.05). CONCLUSIONS: MCA can significantly improve subjective image quality, overall evaluability and diagnostic accuracy of CCT. KEY POINTS: Cardiac computed tomographic coronary angiography (CCT) allows non-invasive evaluation of coronary arteries. Intra-cycle motion correction algorithm (MCA) allows for compensation of coronary motion. An MCA improves image quality, CCT evaluability and diagnostic accuracy.

Coronary artery disease: diagnostic accuracy of CT coronary angiography--a comparison of high and standard spatial resolution scanning.

PURPOSE: To compare the image quality, evaluability, diagnostic accuracy, and radiation exposure of high-spatial-resolution (HR, 0.23-mm) computed tomographic (CT) coronary angiography with standard spatial resolution (SR, 0.625-mm) 64-section imaging in patients at high risk for coronary artery disease (CAD) by using invasive coronary angiography (ICA) as the reference method. MATERIALS AND METHODS: Written informed consent was obtained from all patients, and the study protocol was approved by the institutional ethical committee. Patients at high risk for CAD (n = 184) who were scheduled for ICA were randomly assigned for study with SR (n = 91) or HR (n = 93) coronary CT angiography before they underwent ICA. To compare the two groups, the Student t test or Wilcoxon test were used to evaluate differences in continuous variables. The χ(2) test or Fisher exact test were used, as appropriate, for categorical data. The McNemar test was used to compare the diagnostic performance of coronary CT angiography versus that of ICA in each group. RESULTS: HR coronary CT angiography showed a higher image quality score (3.7 vs 3.4, P < .001) and evaluability (97% vs 92%, P < .002). In a segment-based analysis, HR coronary CT angiography showed a higher specificity, positive predictive value, and accuracy in comparison with SR coronary CT angiography (98%, 91%, and 99% vs 95%, 80%, and 95%, respectively; P < .001). Moreover, HR coronary CT angiography showed a better agreement with ICA for calcified plaques compared with SR coronary CT angiography and ICA (83% vs 53%, P < .001). In a patient-based analysis, HR coronary CT angiography showed higher specificity and accuracy compared with SR coronary CT angiography (91% and 98% vs 46% and 92%, respectively; P < .01). No differences in radiation exposure were found between the two groups. CONCLUSION: Improved evaluability and accuracy were seen with HR compared with SR coronary CT angiography of calcified coronary artery lesions, suggesting a potential use for this technology in patients at high risk for CAD.

Diagnostic accuracy of multidetector computed tomography coronary angiography in 325 consecutive patients referred for transcatheter aortic valve replacement.

BACKGROUND: Multidetector computed tomography (MDCT) provides detailed assessment of valve annulus and iliofemoral vessels in transcatheter aortic valve replacement (TAVR) patients. However, data on diagnostic performance of MDCT coronary angiography (MDCT-CA) are scarce. The aim of the study is to assess diagnostic performance of MDCT for coronary artery evaluation before TAVR. METHODS: A total of 325 consecutive patients (234 without previous myocardial revascularization, 49 with previous coronary stenting, and 42 with previous coronary artery bypass graft [CABG]) underwent invasive coronary angiography and MDCT before TAVR. MDCT-CA was performed using the same data set dedicated to standard MDCT aortic annulus evaluation. Multidetector computed tomography-CA evaluability and diagnostic accuracy in comparison with invasive coronary angiography as criterion standard were assessed. RESULTS: The MDCT-CA evaluability of native coronaries was 95.6%. The leading cause of unevaluability was beam-hardening artifact due to coronary calcifications. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting ≥50% stenosis of 91%, 99.2%, 83.4%, 99.6% and 98.8%, respectively. The MDCT-CA evaluability of coronary stents was 82.1%. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy for detecting ≥50% in-stent restenosis of 94.1%, 86.7%, 66.7%, 98.1%, and 88.3%, respectively. All CABGs were correctly assessed by MDCT-CA. In a patient-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy of 89.7%, 90.8%, 80.6%, 95.4%, and 90.5%, respectively. CONCLUSIONS: Multidetector computed tomography-CA allows to correctly rule out the presence of significant native coronary artery stenosis, significant in-stent restenosis, and CABG disease in patients referred for TAVR.

Quantifying Carotid Stenosis: History, Current Applications, Limitations, and Potential: How Imaging Is Changing the Scenario.

Carotid artery stenosis is a major cause of morbidity and mortality. The journey to understanding carotid disease has developed over time and radiology has a pivotal role in diagnosis, risk stratification and therapeutic management. This paper reviews the history of diagnostic imaging in carotid disease, its evolution towards its current applications in the clinical and research fields, and the potential of new technologies to aid clinicians in identifying the disease and tailoring medical and surgical treatment.

GP64-pseudotyped lentiviral vectors target liver endothelial cells and correct hemophilia A mice.

Lentiviral vectors (LV) are efficient vehicles for in vivo gene delivery to the liver. LV integration into the chromatin of target cells ensures their transmission upon proliferation, thus allowing potentially life-long gene therapy following a single administration, even to young individuals. The glycoprotein of the vesicular stomatitis virus (VSV.G) is widely used to pseudotype LV, as it confers broad tropism and high stability. The baculovirus-derived GP64 envelope protein has been proposed as an alternative for in vivo liver-directed gene therapy. Here, we perform a detailed comparison of VSV.G- and GP64-pseudotyped LV in vitro and in vivo. We report that VSV.G-LV transduced hepatocytes better than GP64-LV, however the latter showed improved transduction of liver sinusoidal endothelial cells (LSEC). Combining GP64-pseudotyping with the high surface content of the phagocytosis inhibitor CD47 further enhanced LSEC transduction. Coagulation factor VIII (FVIII), the gene mutated in hemophilia A, is naturally expressed by LSEC, thus we exploited GP64-LV to deliver a FVIII transgene under the control of the endogenous FVIII promoter and achieved therapeutic amounts of FVIII and correction of hemophilia A mice.

Predictors of adverse cardiac events of coronary myocardial bridging diagnosed with computed tomography angiography.

AIMS: Myocardial bridging (MB) is a frequent congenital anomaly of the epicardial coronary arteries commonly considered a benign condition. However, in some cases a complex interplay between anatomical, clinical and physiology factors may lead to adverse events, including sudden cardiac death. Coronary CT angiography (CCTA) emerged as the gold standard noninvasive imaging technique for the evaluation of MB. Aim of the study was to evaluate MB prevalence and anatomical features in a large population of patients who underwent CCTA for suspected CAD and to identify potential anatomical and clinical predictors of adverse cardiac events at long-term follow-up. METHODS AND RESULTS: Two-hundred and six patients (mean age 60.3 ± 11.8 years, 128 male) with MB diagnosed at CCTA were considered. A long MB was defined as ≥25 mm of overlying myocardium, whereas a deep MB as ≥2 mm of overlying myocardium. The study endpoint was the sum of the following adverse events: cardiac death, bridge-related acute coronary syndrome, hospitalization for angina or bridge-related ventricular arrhythmias and MB surgical treatment. Of the 206 patients enrolled in the study, 9 were lost to follow-up, whereas 197 (95.6%) had complete follow-up (mean 7.01 ± 3.0 years) and formed the analytic population. Nineteen bridge-related events occurred in 18 patients (acute coronary syndrome in 7, MB surgical treatment in 2 and hospitalization for bridge-related events in 10). Typical angina at the time of diagnosis and long MB resulted as significant independent predictors of adverse outcome. CONCLUSIONS: Typical angina and MB length ≥ 25 mm were independent predictors of cardiac events.