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Background. Percutaneous occlusion under fluoroscopy guidance has become the preferred method for the treatment of patent ductus arteriosus (PDA). To avoid radiation exposure and contrast agent use, PDA occlusion under transthoracic echocardiography (TTE) guidance was conducted. Objectives. We assessed the hypothesis that the success rate of percutaneous PDA occlusion under TTE was noninferior to that under fluoroscopy guidance. Methods. In this single-center trial, 100 patients were randomly assigned in a 1 : 1 ratio to the TTE group (n = 50) or to the fluoroscopy group (n = 50). The primary endpoint was the success rate of occlusion, with the noninferiority margin set at 8% for the between-group difference in intention-to-treat analysis. Secondary endpoints were hospitalization duration, cost, procedure time, and rate of adverse events including occluder migration, hemolysis, peripheral vascular complications, and residual shunt at 1-month and 12-month follow-up. Results. Patient, defect, and device characteristics were similarly distributed between groups. The success rate of occlusion was 98% for the TTE group and 100% for the fluoroscopy group (absolute difference: −2%; 95% confidence interval: −5.9% to 1.9%). Cost and procedure duration were significantly lower in the TTE group, without adverse events in either group at a median of 12.0 months (range, 10.0–15.5 months) of follow-up. Conclusion. Percutaneous PDA occlusion can be performed via TTE guidance safely and effectively, and the success rate of the TTE-guided procedure was noninferior to that under fluoroscopy guidance, with reduced cost and procedure time. The trial is registered with http://www.chictr.org.cn (ChiCTR-ICR-15006334).

Objectives This study was conducted to investigate the combined use of fenestrated atrial septal occluder (F-ASO) and targeted medical therapy (TMT) in patients with secundum atrial septal defect (ASD) and severe pulmonary arterial hypertension (PAH). Background Treatment of patients with ASD and severe PAH is still challenging. Methods After ethical approval was obtained, 56 consecutive patients with ASD with severe PAH were included (7 men, 49 women; median age 50.5 years; mean ASD size 26.9 ± 4.6 mm). After 3 months of TMT, transcatheter closure was performed using F-ASO in patients with ratios of pulmonary to systemic blood flow ≥1.5. TMT was continued post-operatively together with 6 months of dual-antiplatelet therapy. The hemodynamic variables during baseline, TMT alone, and combined treatment with F-ASO were compared. Results After only TMT, systolic pulmonary arterial pressure (−14.5 mm Hg; p Conclusions In patients with ASD and severe PAH, combination of F-ASO and TMT was a safe and effective procedure. Compared with TMT alone, the combined treatment further improved exercise capacity, with favorable cardiac remodeling.

Background A percutaneous approach for pulmonary valve replacement (PVR) is a feasible alternative to surgical PVR in selected patients with severe pulmonary regurgitation after repair of tetralogy of Fallot. However, large right ventricular outflow tract (diameter ≥ 25 mm) remains challenging. Methods This retrospective multicenter study enrolled consecutive patients with large right ventricular outflow tract who underwent percutaneous PVR (Venus P-valve, Venus MedTech Inc, Hangzhou, China) (n = 35) or surgical PVR (homograft valve; n = 30) between May 2014 and April 2017. Patients were followed up at 1, 3, 6, and 12 months, and yearly thereafter. Main study outcomes were pulmonary valve function and right ventricular function at discharge and midterm follow-up. Results PVR was successful in all patients. Percutaneous compared with surgical PVR group had: similarly distributed baseline characteristics; shorter hospitalization, intensive care unit stay, and endotracheal intubation duration; lower cost; lower pulmonary valve gradient before discharge; lower pulmonary valve regurgitant grade (mean difference, –0.63; 95% CI –1.11 to –0.20, P = .022), pulmonary valve gradient (mean difference, –5.7 mm Hg; 95% CI –9.4 to –2.2 mm Hg, P = .005), and right ventricular end-diastolic volume index (mean difference, –9.5 mL/m2; 95% CI –16.9 to –3.1 mL/m2, P = .022); and greater right ventricular ejection fraction (mean difference, 5.4%; 95% CI 2.4%-8.3%, P = .002) at median 36 months follow-up, without deaths in either group. Conclusions Percutaneous PVR using Venus P-valve appeared to be a safe, efficacious and minimally invasive alternative to surgical PVR in selected patients with large right ventricular outflow tract yielding better right ventricular and pulmonary valve function at midterm follow-up.

Background. To evaluate the feasibility of using a single device to close multiple atrial septal defects (ASDs) under the guidance of transthoracic echocardiography (TTE) and with the aid of three-dimensional (3D) printing models. Methods. Sixty-two patients with multiple ASDs were retrospectively analyzed. Thirty of these patients underwent TTE-guided closure (3D printing and TTE group) after a simulation of occlusion in 3D printing models. The remaining 32 patients underwent ASD closure under fluoroscopic guidance (conventional group). Closure status was assessed immediately and at 6 months after device closure. Results. Successful transcatheter closure with a single device was achieved in 26 patients in the 3D printing and TTE group and 27 patients in the conventional group. Gender, age [18.8 ± 15.9 (3–51) years in the 3D printing and TTE group; 14.0 ± 11.6 (3–50) years in the conventional group], mean maximum distance between defects, prevalence of 3 atrial defects and large defect distance (defined as distance ≥7 mm), and occluder size used were similarly distributed between groups. However, the 3D printing and TTE group had lower frequency of occluder replacement (3.8% vs 59.3%, p<0.0001), prevalence of mild residual shunts (defined as p<0.05) and at 6 months (7.7% vs 29.6%, p<0.05) after the procedure, and cost (32960.8 ± 2018.7 CNY vs 41019.9 ± 13758.2 CNY, p<0.01). Conclusion. The combination of the 3D printing technology and ultrasound-guided interventional procedure provides a reliable new therapeutic approach for multiple ASDs, especially for challenging cases with large defect distance.

Background Percutaneous balloon aortic valvuloplasty (PBAV) is an alternative to surgical valvulotomy for the treatment of congenital aortic stenosis (AS). This article aims to summarize our preliminary experience on feasibility and safety of PBAV under only echocardiographic guidance in patients with congenital AS. Methods Clinical data from 20 consecutive patients with aortic valve stenosis who underwent PBAV under only echocardiographic guidance at Fuwai Hospital from January 2016 to January 2019 were analyzed retrospectively. Median age of patients was 18.38±15.88 years and 65% of the patients were male. Aortic annulus diameter was 18.40±3.25 mm and balloon diameter was 17.38±3.89 mm, with B/A ratio of 0.93±0.06. Results All the patients successfully underwent PBAV. The peak transaortic gradient (TG) significantly decreased from 81.59±24.91 (range, 58-112) mmHg preoperatively to 36.32±12.83 (range, 16-51) mmHg (P=0.000) immediately post operation, without significant difference in aortic regurgitation (AR). At mean 24.31±17.35 months follow-up, peak TG was 37.06±13.52 (range, 21-58) mmHg which was not significantly different from the immediate postoperative value (P=0.65). Conclusions In this retrospective, single center study, systematic use of Doppler echocardiography as only guidance modality for PBAV was feasible and associated with a high success rate and a very low complication rate.

The objective of this study was to evaluate the ability of the phytohormone S-abscisic acid (S-ABA) to protect maize seedlings grown under drought stress and to measure their increased drought tolerance. The maize hybrids ‘Zhengdan 958’ (ZD958; drought tolerant) and ‘Xundan 20’ (XD20; drought sensitive) were treated with nutrient solutions of different concentrations (1, 2, 4, 8, and 10 mg/kg) of S-ABA under polyethylene glycol (PEG, 15% w/v, MW 6000) simulated drought stress. Optimal concentrations of S-ABA were designed to be sprayed onto the leaves of seedlings, and their effect on endogenous ABA, malondialdehyde (MDA), osmotic substances, antioxidant enzyme activities, and Asr1 gene expression in seedlings were studied. Results indicated that, under drought stress, S-ABA treatment significantly improved maize seed germination rate (GR), germination energy (GE), and seedling biomass (p

BACKGROUND: Minimally-invasive-perventricular-device-occlusion (MIPDO) combined superiority of surgical-repair and percutaneous-device-closure in treating perimembranous-ventricular-septal-defect (pmVSD). This study was to evaluate the efficacy and safety of MIPDO for treating pmVSD, comparing with surgical-repair. METHODS: Patients aged ≥3 months with isolated pmVSDs were randomized to undergo either surgical or MIPDO procedure, with the median follow-up time of 49 months. The primary outcome was the rate of complete pmVSD closure at discharge. The secondary outcomes included the adverse events during hospitalization and follow-up, chest tube output volume, blood transfusion volume, procedural duration, ventilation time, hospitalization duration and hospitalization cost. Also, perioperative cardiac performance and systemic conditions were evaluated. RESULTS: Of the 313 patients (9 months to 42 years old; median, 4 years old) with pmVSDs recruited from 3 centers, 100 were finally enrolled and randomly allocated 1:1 into two groups. The non-inferiority (non-inferiority margin −8.0%) of MIPDO to surgical closure regarding efficacy was shown in both intention-to-treat (0, 95% CI: −0.055 to 0.055) and per-protocol populations (0.02, 95% CI: −0.018 to 0.058). Although the rate of adverse events was similar between groups, the MIPDO group showed superiority in procedural duration, ventilation time, chest tube output volume, postoperative hospitalization time and hospitalization cost compared with surgical group (P

Neutralizing antibodies elicited by prior infection or vaccination are likely to be key for future protection of individuals and populations against SARS-CoV-2. Moreover, passively administered antibodies are among the most promising therapeutic and prophylactic anti-SARS-CoV-2 agents. However, the degree to which SARS-CoV-2 will adapt to evade neutralizing antibodies is unclear. Using a recombinant chimeric VSV/SARS-CoV-2 reporter virus, we show that functional SARS-CoV-2 S protein variants with mutations in the receptor-binding domain (RBD) and N-terminal domain that confer resistance to monoclonal antibodies or convalescent plasma can be readily selected. Notably, SARS-CoV-2 S variants that resist commonly elicited neutralizing antibodies are now present at low frequencies in circulating SARS-CoV-2 populations. Finally, the emergence of antibody-resistant SARS-CoV-2 variants that might limit the therapeutic usefulness of monoclonal antibodies can be mitigated by the use of antibody combinations that target distinct neutralizing epitopes., eLife digest The new coronavirus, SARS-CoV-2, which causes the disease COVID-19, has had a serious worldwide impact on human health. The virus was virtually unknown at the beginning of 2020. Since then, intense research efforts have resulted in sequencing the coronavirus genome, identifying the structures of its proteins, and creating a wide range of tools to search for effective vaccines and therapies. Antibodies, which are immune molecules produced by the body that target specific segments of viral proteins can neutralize virus particles and trigger the immune system to kill cells infected with the virus. Several technologies are currently under development to exploit antibodies, including vaccines, blood plasma from patients who were previously infected, manufactured antibodies and more. The spike proteins on the surface of SARS-CoV-2 are considered to be prime antibody targets as they are accessible and have an essential role in allowing the virus to attach to and infect host cells. Antibodies bind to spike proteins and some can block the virus’ ability to infect new cells. But some viruses, such as HIV and influenza, are able to mutate their equivalent of the spike protein to evade antibodies. It is unknown whether SARS-CoV-2 is able to efficiently evolve to evade antibodies in the same way. Weisblum, Schmidt et al. addressed this question using an artificial system that mimics natural infection in human populations. Human cells grown in the laboratory were infected with a hybrid virus created by modifying an innocuous animal virus to contain the SARS-CoV-2 spike protein, and treated with either manufactured antibodies or antibodies present in the blood of recovered COVID-19 patients. In this situation, only viruses that had mutated in a way that allowed them to escape the antibodies were able to survive. Several of the virus mutants that emerged had evolved spike proteins in which the segments targeted by the antibodies had changed, allowing these mutant viruses to remain undetected. An analysis of more than 50,000 real-life SARS-CoV-2 genomes isolated from patient samples further showed that most of these virus mutations were already circulating, albeit at very low levels in the infected human populations. These results show that SARS-CoV-2 can mutate its spike proteins to evade antibodies, and that these mutations are already present in some virus mutants circulating in the human population. This suggests that any vaccines that are deployed on a large scale should be designed to activate the strongest possible immune response against more than one target region on the spike protein. Additionally, antibody-based therapies that use two antibodies in combination should prevent the rise of viruses that are resistant to the antibodies and maintain the long-term effectiveness of vaccines and therapies.

The HIV-1 Vpr accessory protein induces ubiquitin/proteasome-dependent degradation of many cellular proteins by recruiting them to a cullin4A-DDB1-DCAF1 complex. In so doing, Vpr enhances HIV-1 gene expression and induces (G2/M) cell cycle arrest. However, the identities of Vpr target proteins through which these biological effects are exerted are unknown. We show that a chromosome periphery protein, CCDC137/cPERP-B, is targeted for depletion by HIV-1 Vpr, in a cullin4A-DDB1-DCAF1 dependent manner. CCDC137 depletion caused G2/M cellcycle arrest, while Vpr-resistant CCDC137 mutants conferred resistance to Vpr-induced G2/M arrest. CCDC137 depletion also recapitulated the ability of Vpr to enhance HIV-1 gene expression, particularly in macrophages. Our findings indicate that Vpr promotes cell-cycle arrest and HIV-1 gene expression through depletion of CCDC137., eLife digest Like all viruses, the human immunodeficiency virus 1 (HIV-1) cannot replicate on its own; to multiply, it needs to exploit the molecular machinery of a cell. A set of HIV-1 proteins is vital in this hijacking process, and they are required for the virus to make more of itself. However, HIV-1 also carries accessory proteins that are not absolutely necessary for the replication process, but which boost the growth of the virus by deactivating the defences of the infected cells. Amongst these proteins, the role of Viral Protein R (Vpr for short) has been particularly enigmatic. Previous experiments have shown that, in infected cells, Vpr is linked to several biological processes: it tags for destruction a large number of proteins, it causes the cells to stop dividing, and it encourages them to express the genetic information of the virus. How these different processes are connected and triggered by Vpr is still unknown. It particular, it remains unclear which protein is responsible for these changes when it is destroyed by Vpr. To investigate, Zhang and Bieniasz conducted a series of experiments to spot the proteins that interact with Vpr in human cells. This screening process highlighted a protein known as CCDC137, which is depleted in cells infected by HIV-1. To investigate the role of CCDC137, Zhang and Bieniasz decreased the levels of the protein in human cells. This stopped the cells from dividing, just like during HIV-1 infection. Destroying CCDC137 also mimicked the effects of Vpr on HIV-1 gene expression, increasing the levels of virus proteins in infected cells. Finally, Zhang and Bieniasz made a mutant version of CCDC137 that Vpr could not destroy. When infected cells carried this mutant protein, they kept on dividing as normal. Taken together, these results suggest that Vpr works by triggering the destruction of the CCDC137 protein. Overall, this work represents the first step to understand the role of CCDC137 in both infected and healthy cells.

Background Transcatheter device closure has become an alternative therapy for ventricular septal defect (VSD). This study aimed to investigate the feasibility and safety of transcatheter perimembranous VSD (pm-VSD) closure under transthoracic echocardiography (TTE) guidance alone. Methods Between October 2012 and July 2016, 118 patients with pm-VSD underwent an attempt of transcatheter device closure for pm-VSD through the femoral artery under TTE guidance alone. Patients were followed-up at 1, 3, 6, and 12 months after the procedure and yearly after discharge. Results The mean age was 11.7±12.5 years (range, 1.0-53.0 years) and the mean body weight was 32.2±21.6 kg (range, 11.5-102.0 kg). The mean diameter of the VSD was 4.0±1.1 mm (range, 3.0-8.0 mm). Transcatheter device closure under TTE guidance alone was successful in 111 patients. The average procedural time was 44.9±7.3 minutes (range, 29.0-65.0 minutes). All 111 patients were followed-up for 3.4±2.3 years. At the last follow-up, two patients had a residual shunt smaller than 2 mm, seven patients had right bundle branch block (RBBB) including one patient with complete RBBB, six patients had mild or less tricuspid regurgitation, and two patients still had trivial aortic regurgitation including one patient that had it before the procedure. Occluder malposition, complete atrioventricular block, or other complications were not observed. Conclusions Transcatheter pm-VSD closure can be successfully performed under TTE guidance alone with outcomes similar to those achieved with fluoroscopic guidance in selected patients with weight more than 10 kg and VSD smaller than 8 mm. However, long-term follow-up in a large number of patients would be necessary.

Percutaneous balloon pulmonary valvuloplasty (PBPV) is the procedure of choice for uncomplicated severe or symptomatic pulmonary stenosis. Echocardiography (echo)-guided PBPV can completely avoid the use of radiation and contrast agents compared to fluoroscopy-guided PBPV. Although we have confirmed that echo-guided PBPV is feasible in humans, the poor visibility of the traditional catheter under echo greatly limits the promotion of this new technology.We produced a novel double-balloon catheter to make the catheter easy to be detected by echo through adding a guiding balloon at the distal end of the catheter. Echo-guided PBPV was performed on thirty healthy swine using either a novel catheter or a traditional catheter to evaluate the feasibility and safety of the novel double-balloon catheter. The feasibility was evaluated by the success rate of balloon inflation at the pulmonary valve annulus and the operating time. The safety was evaluated by the frequency of balloon slippage and the incidence of complications.There were no significant between-group differences in terms of weight and the ratio of balloon diameter to pulmonary annulus diameter. The success rate was 93.3% and 60% in the novel and traditional groups, respectively. The novel group had significantly (p0.05) lower mean procedure time (6.33±6.86min vs 24.8±9.79min) and lower frequency of balloon slippage (0.07±0.26 vs 0.53±0.52), arrhythmia (0.07±0.26 vs 0.47±0.52), and tricuspid regurgitation (6.7% vs 40%) than the traditional group. No myocardial hematoma or pericardial tamponade occurred in the novel catheter group.Although further studies and improvements are required, the study results indicate that the novel double-balloon catheter for echo-guided PBPV is feasible and safe.

Use of partially bioabsorbable occluders for atrial septal defect closure appears to circumvent potential late complications of metallic occluders ([1][1],[2][2]), which are amply used worldwide. However, there have been no studies on the use of either partially or fully bioabsorbable occluders for

QYM201, 1-(2-chloro-3-(3-cyclopropyl-5-hydroxy-1-methyl-1H-pyrazole-4-carbonyl)-6-(trifluoromethyl)phenyl)piperidin-2-one), is a newly developed HPPD- (4-hydroxyphenylpyruvate dioxygenase; EC 1.13.11.27) inhibiting herbicide for weed control. Experiments were carried out to determine the effect of QYM201 on weeds and its safety for wheat in the glasshouse and field. The results indicated that at doses of 90 and 135 g active ingredient (a.i.) ha−1 QYM201 was highly effective against both grass and broadleaf weeds, such as Alopecurus aequalis Sobol., Alopecurus japonicus Steud, and Capsella bursa-pastoris Medic. In a wheat hybrid tolerance experiment, QYM201 showed a high level of safety for most of the 17 tested wheat hybrids, and the SI values reached ≥5.7 in the selectivity index study. To determine application rules for QYM201, field experiments were conducted in 2016 and 2017. During this time, 90 to 270 g a.i. ha−1 post-emergence herbicide application (POST) was sufficient to supply satisfactory all-season control of Alopecurus aequalis Sobol., Descurainia sophia [L.] Schur., and Malachium aquaticum (L.) Fires. No damage to wheat plants was observed. In order to increase wheat yield and deliver effective weed control, a dosage of 90 to 180 g a.i. ha−1 is suggested. In conclusion, the herbicide QYM201 is safe to use in wheat fields to control winter weeds.

Objective The objective of this study was to assess the feasibility of percutaneous balloon pulmonary valvuloplasty (PBPV) under echocardiographic guidance only. Setting PBPV has become the preferred choice for pulmonary valve stenosis (PS). We report the first-in-human successful PBPV under only echocardiography guidance for isolated PS. Methods From March 2013 to December 2014, 34 patients with congenital PS underwent PBPV with echocardiography as the only imaging modality in the ordinary operation room or catheter lab. Outpatient follow-up including chest radiography, electrocardiography, and transthoracic echocardiography (TTE) was conducted at 1, 3, 6, and 12 months. Results All 34 patients successfully underwent PBPV under echocardiography guidance without radiation and contrast agent. The pulmonic transvalvular pressure gradient dropped from 62.8 ± 10.1 mm Hg to 14.7 ± 4.2 mm Hg measured on catheterization (P

Myosoton aquaticum L., a widespread and competitive winter weed of wheat in China, has evolved resistance to many classes of herbicides. In one M. aquaticum population (AH03), collected from Anhui Province, where tribenuron-methyl and florasulam had been used to control this weed resistance to both herbicides had evolved. Compared with the sensitive population, HN03(S), the resistant (R) population, AH03, was highly resistant to tribenuron-methyl, flucarbazone-Na and pyroxsulam, moderately resistant to pyrithiobac‑sodium, and florasulam, and had low resistance to diflufenican. AH03 was still controlled by imazethapyr, 2,4-D butylate, fluroxypyr-meptyl, and isoproturon. Pretreatment with the P450 inhibitor malathion reduced the GR50 value of tribenuron-methyl by 43% in the R population, and by 25% in the S population. This indicates that P450-mediated enhanced metabolism is one likely mechanism for tribenuron-methyl resistance in M. aquaticum. Glutathione-S-transferase (GST) activity could be induced by tribenuron-methyl in both the R and S populations. However, both the basal and induced GST activity of the R population was lower than that of the S population. The in vitro ALS assay confirmed that the ALS from the R plants showed a high resistance (52.93-fold) to tribenuron-methyl. ALS gene sequencing revealed a Pro197Ala substitution in the R plants. Based on the ALS gene sequence analysis, molecular markers were also developed to identify the specific Pro197Ala mutation. This population of M. aquaticum has multiple resistance and target-site (ALS Pro197Ala) and non-target-site resistance mechanisms contribute to tribenuron-methyl resistance.

Objective To evaluate the feasibility, efficacy, and safety of a fully biodegradable poly lactic acid (PLA)-based occluder for atrial septal defect (ASD) closure in an animal model. Methods ASDs, approximately 12-mm in diameter, were generated in sheep (n = 18) by needle puncture and balloon dilatation. For ASD closure, occluders were implanted by percutaneous transcatheter approach under echocardiographic guidance. Outcomes were evaluated by transthoracic echocardiography, electrocardiography, blood testing, and histology within the follow-up period ranging from 1 month to 2 years. Results All occluders were successfully implanted. During follow-up, no animal died; rectal temperatures, blood test results, and electrocardiograms were within normal ranges; and transthoracic echocardiograms, macroscopic studies, and histopathological and electron microscopic examination demonstrated that the occluders were well positioned, with no shifting, residual shunts, severe inflammation, thrombus formation, atrioventricular valve insufficiency, cardiac erosion or arrhythmias. The occluders gradually embedded into the endocardial tissue of the hosts with complete endothelialization and disk absorption at 12 months, and a distinct molecular weight decrease of the framework (to 9% of initial) at 24 months after implantation. Conclusions In a sheep model, the use of totally biodegradable occluders appears feasible, efficacious and safe for ASD closure. Studies in humans are ongoing.

Summary Interferons (IFNs) exert their anti-viral effects by inducing the expression of hundreds of IFN-stimulated genes (ISGs). The activity of known ISGs is insufficient to account for the antiretroviral effects of IFN, suggesting that ISGs with antiretroviral activity are yet to be described. We constructed an arrayed library of ISGs from rhesus macaques and tested the ability of hundreds of individual macaque and human ISGs to inhibit early and late replication steps for 11 members of the retroviridae from various host species. These screens uncovered numerous ISGs with antiretroviral activity at both the early and late stages of virus replication. Detailed analyses of two antiretroviral ISGs indicate that indoleamine 2,3-dioxygenase 1 (IDO1) can inhibit retroviral replication by metabolite depletion while tripartite motif-56 (TRIM56) accentuates ISG induction by IFNα and inhibits the expression of late HIV-1 genes. Overall, these studies reveal numerous host proteins that mediate the antiretroviral activity of IFNs., Graphical Abstract Image 1, Highlights • ISG screening identifies direct and indirect antiretroviral proteins • Interferon-γ inhibits HIV-1 through IDO1-mediated tryptophan depletion • TRIM56 enhances the antiretroviral potential of interferon-α, Screening of interferon-stimulated genes for antiretroviral activity reveals numerous genes that directly or indirectly inhibit retroviral replication. Detailed analyses of two antiretroviral effectors indicate that IDO1 inhibits retroviral replication via nutrient depletion while TRIM56 increases the antiretroviral potential of IFNα.

Objective. To assess the effectiveness of a novel ultrasound wire for echo-guiding percutaneous atrial septal defect (ASD) closure in a sheep model. Methods. After right lateral thoracotomy, ASDs were created in 20 sheep by transseptal needle puncture followed by balloon dilatation. Animals were evenly randomized into 2 groups to undergo ASD closure using echography as the only imaging tool with either COOK wire (control group) or new ultrasound wire (study group). The total procedural time, passing time (time needed for the guide wire to enter the left atrium), frequency of delivery sheath dropping into the right atrium, frequency of arrhythmias, and 1-week rate of complications were compared between the two groups. Results. All animals survived defect creation procedures uneventfully. ASD devices were successfully implanted in all sheep. Compared with the control group, the study group had significantly (P<0.05) lower mean procedure time (15.36 ± 4.86 versus 25.82 ± 7.85 min), lower mean passing time (2.69 ± 0.82 versus 5.58 ± 3.34 min), lower frequency of the guide wire dropping into the right atrium (0% versus 40%), and lower frequency of atrial (4.41 ± 2.61 versus 9.60 ± 3.68) or ventricular premature contractions (0.75 ± 0.36 versus 1.34 ± 0.68), respectively, without serious complications up to one week. Conclusion. The novel ultrasound specialized guide wire was effective in echo-guiding percutaneous ASD closure.

Surgical or percutaneous interventional treatment of severe congenital aortic valve stenosis (CAS) in early infancy remains challenging. This single-center, retrospective study analyzed midterm outcomes of a hybrid balloon valvuloplasty procedure through the ascending aorta by way of median sternotomy, including cases with improved technique.Included were 45 consecutive infants (aged90 days) with CAS and selected for biventricular repair who underwent hybrid balloon valvuloplasty in a hybrid or ordinary operating room from October 2010 to March 2016. Patients were assessed at 1, 3, 6, and 12 months and yearly thereafter.Hybrid balloon valvuloplasty was successful in all patients, with the last 8 treated in an ordinary operating room under only echocardiography guidance with a new sheath. Thirty-two patients were successfully rescued from low heart rate or left ventricular systolic dysfunction, or both, by cardiac massage under direct visualization; none required cardiopulmonary bypass. The degree of new aortic insufficiency was mild in 7 patients and changed from mild to moderate in 1 patient. Aortic valve pressure gradient decreased from 70.6 ± 17.5 mm Hg preoperatively to 15.2 ± 4.2 mm Hg immediately postoperatively (p0.001). Fluoroscopy time was 4.8 ± 2.3 minutes. At a median of 32.1 months (range, 1 to 68 months) follow-up, all patients were alive and healthy. Aortic valve pressure gradient remained low (19.1 ± 5.2 mm Hg). Left ventricular ejection fraction increased from 0.515 ± 0.134 (range, 0.21 to 0.70) preoperatively to 0.633 ± 0.035 (range, 0.58 to 0.75; p0.001). No aortic insufficiency developed, and no patient required reintervention.For infants with severe CAS, hybrid balloon valvuloplasty through the ascending aorta by way of a median sternotomy appears efficacious and safe up to midterm follow-up.

Xenotropic murine leukemia virus-related virus (XMRV) is a novel retrovirus, related to murine leukemia virus (MLV), that has been implicated in human disease. If XMRV is indeed able to replicate in humans, then one might predict that XMRV would have developed resistance to human innate antiviral resistance factors such as APOBEC3G (hA3G). In fact, we observed that XMRV and MLV are both highly sensitive to inhibition by hA3G and equally resistant to inhibition by murine APOBEC3. While several human prostate cancer cell lines were found to lack hA3G, stable expression of physiological levels of hA3G rendered these cells refractory to XMRV replication. Few human tissues fail to express hA3G, and we therefore hypothesize that XMRV replicates in one or more hA3G-negative reservoir tissues and/or that human XMRV infections are likely to be rare and potentially of zoonotic origin.

The dynamics of the late stages of the HIV-1 life cycle are poorly documented. Viral replication dynamics are typically measured in populations of infected cells, but asynchrony that is introduced during the early steps of HIV-1 replication complicates the measurement of the progression of subsequent steps and can mask replication dynamics and their variation in individual infected cells. We established microscopy-based methods to dynamically measure HIV-1-encoded reporter gene and antiviral gene expression in individual infected cells. We coupled these measurements with conventional analyses to quantify delays in the HIV-1 replication cycle imposed by the biphasic nature of HIV-1 gene expression and by the assembly-inhibiting property of the matrix domain of Gag. We further related the dynamics of restriction factor (APOBEC3G) removal to the dynamics of HIV-1 replication in individual cells. These studies provide a timeline for key events in the HIV-1 replication cycle, and reveal that the interval between the onset of early and late HIV-1 gene expression is only ~3h, but matrix causes a ~6–12h delay in the generation of extracellular virions. Interestingly, matrix delays particle assembly to a time at which APOBEC3G has largely been removed from the cell. Thus, a need to prepare infected cells to be efficient producers of infectious HIV-1 may provide an impetus for programmed delays in HIV-1 virion genesis. Our findings also emphasize the significant heterogeneity in the length of the HIV-1 replication cycle in homogenous cell populations and suggest that a typical infected cell generates new virions for only a few hours at the end of a 48h lifespan. Therefore, small changes in the lifespan of infected cells might have a large effect on viral yield in a single cycle and the overall clinical course in infected individuals., Author Summary The HIV-1 replication cycle is composed of several sequential steps. While the timing of the early steps of HIV-1 replication is quite well understood, measuring the duration of later steps is complicated by the fact that asynchrony is introduced into populations of infected cells during early steps. We devised imaging methods for measuring the duration of late steps in HIV-1 replication in single infected cells, circumventing the problems associated with measurements in populations of asynchronously infected cells. By combining these measurements with conventional analyses of HIV-1 replication in populations of cells, we derived a time-line of key events during the late steps of the HIV-1 life cycle. We find that the delay between early and late gene expression is small but that a subsequent programmed delay in virus assembly enables HIV-1 to remove a host antiviral protein from infected cells before new virions are generated. In so doing, HIV-1 may prevent futile virion production.

The morphogenesis of retroviral particles is driven by Gag and GagPol proteins that provide the major structural component and enzymatic activities required for particle assembly and maturation. In addition, a number of cellular proteins are found in retrovirus particles; some of these are important for viral replication, but many lack a known functional role. One such protein is clathrin, which is assumed to be passively incorporated into virions due to its abundance at the plasma membrane. We found that clathrin is not only exceptionally abundant in highly purified HIV-1 particles but is recruited with high specificity. In particular, the HIV-1 Pol protein was absolutely required for clathrin incorporation and point mutations in reverse transcriptase or integrase domains of Pol could abolish incorporation. Clathrin was also specifically incorporated into other retrovirus particles, including members of the lentivirus (simian immunodeficiency virus, SIVmac), gammaretrovirus (murine leukemia virus, MLV) and betaretrovirus (Mason-Pfizer monkey virus, M-PMV) genera. However, unlike HIV-1, these other retroviruses recruited clathrin primarily using peptide motifs in their respective Gag proteins that mimicked motifs found in cellular clathrin adaptors. Perturbation of clathrin incorporation into these retroviruses, via mutagenesis of viral proteins, siRNA based clathrin depletion or adaptor protein (AP180) induced clathrin sequestration, had a range of effects on the accuracy of particle morphogenesis. These effects varied according to which retrovirus was examined, and included Gag and/or Pol protein destabilization, inhibition of particle assembly and reduction in virion infectivity. For each retrovirus examined, clathrin incorporation appeared to be important for optimal replication. These data indicate that a number of retroviruses employ clathrin to facilitate the accurate morphogenesis of infectious particles. We propose a model in which clathrin contributes to the spatial organization of Gag and Pol proteins, and thereby regulates proteolytic processing of virion components during particle assembly., Author Summary The assembly and maturation of infectious retroviruses is driven by two viral proteins, Gag and Pol. Additionally, a number of cellular proteins are found in retrovirus particles, many of which lack a known functional role. One such protein is clathrin, which normally mediates several physiological processes in cells and was previously thought to be only passively incorporated into virions. In this study we show that clathrin is actively, specifically and abundantly incorporated into retrovirus particles. In several cases, retroviral proteins encode peptide motifs that mimic those found in cellular adaptor proteins that are responsible for clathrin recruitment. The range of retroviruses into which clathrin is packaged includes human and simian immunodeficiency viruses as well as other murine and simian retroviruses. Manipulations that prevented clathrin incorporation into virions also caused a variety of defects in the genesis of infectious retroviruses, including viral protein destabilization, inhibition of particle assembly and release, and reduction in virion infectiousness. The precise nature of the defect varied according to which particular retrovirus was examined. Overall these studies suggest that clathrin is frequently employed by retroviruses to facilitate the accurate assembly of infectious virions.

Lentiviral Nef proteins have multiple functions and are important for viral pathogenesis. Recently, Nef proteins from many simian immunodefiency viruses were shown to antagonize a cellular antiviral protein, named Tetherin, that blocks release of viral particles from the cell surface. However, the mechanism by which Nef antagonizes Tetherin is unknown. Here, using related Nef proteins that differ in their ability to antagonize Tetherin, we identify three amino-acids in the C-terminal domain of Nef that are critical specifically for its ability to antagonize Tetherin. Additionally, divergent Nef proteins bind to the AP-2 clathrin adaptor complex, and we show that residues important for this interaction are required for Tetherin antagonism, downregulation of Tetherin from the cell surface and removal of Tetherin from sites of particle assembly. Accordingly, depletion of AP-2 using RNA interference impairs the ability of Nef to antagonize Tetherin, demonstrating that AP-2 recruitment is required for Nef proteins to counteract this antiviral protein., Author Summary Primate lentiviruses express several small proteins which antagonize cellular proteins that inhibit virus replication. One such viral protein, Nef, has recently been shown to antagonize the cellular protein Tetherin that prevents newly formed viral particles from leaving the surface of infected cells. In this study we reveal the mechanism by which Nef overcomes inhibition by Tetherin. We show that three amino acids in the Nef C-terminal flexible loop are important for Tetherin antagonism. We also show that the interaction between Nef and AP-2 adaptor complexes is important for Tetherin downregulation from the cell surface, removal from sites of particle assembly and antagonism. Thus, our study demonstrates that AP-2 is important for the ability of Nef to antagonize Tetherin.