Initial Balloon Versus Surgical Valvuloplasty In Children With Isolated Congenital Aortic Stenosis: Impact On Timing Of Aortic Valve Replacement.

OBJECTIVE: To evaluate the influence of initial intervention on the long-term outcomes in congenital aortic stenosis. METHODS: 243 children underwent initial intervention between 1997 and 2022, by surgical valvuloplasty in 92 (32% neonates, 36% infants) and balloon valvuloplasty in 151 (27% neonates, 30% infants). 28 patients (11.5%) had associated mitral valve stenosis. Competing risk analysis for death, alive after initial intervention or alive after AVR was performed and factors affecting survival or AVR examined. RESULTS: There were nine early deaths (3.7%). During a median follow-up of 13.5 years (Range: 1.5-26.7years), 98 patients had re-intervention on the aortic valve (40.3%), while 145 had AVR (59.6%) at a median age of 14.0 years (IQR: 9.0-17.0), which was by Ross procedure in 130 (89.6%). Of the 12 late deaths, 3 were peri-operative and 9 occurred as outpatients. There were no peri-operative or late deaths after AVR. AVR occurred earlier in patients who had initial balloon [12.0 years (IQR: 5.0-14.5)] rather than surgical [18.5 years (IQR: 15.5-21.5)] valvuloplasty (P<.05). Actuarial survival in the cohort was 91.3% at 25 years, with no difference between the two initial interventions. Critical aortic stenosis, mitral stenosis and initial intervention as a neonate were independent risk factors for worse survival. CONCLUSIONS: We demonstrate excellent early and late survival in patients with congenital aortic stenosis after initial balloon or surgical valvuloplasty. Whilst children who had balloon valvuloplasty had AVR earlier than those who had initial surgical valvuloplasty, patient factors had a greater impact on survival than choice of initial intervention.

The early and medium-term results of the Ross procedure in pediatric patients.

INTRODUCTION AND OBJECTIVES: The Ross method is the preferred surgical treatment for pediatric aortic valve diseases, and its long-term outcomes have been extensively documented. This article presents the results of the Ross and Ross-Konno procedures performed on pediatric patients in our center. METHODS: Ross and Ross-Konno procedures were performed on 20 patients in our center between January 2015 and January 2019. RESULTS: The patients' mean age was 10.6 years (range: 23 days to 18 years) and mean weight was 37.6 kg (range: 3-63 kg). 13 had aortic valve stenosis, four had aortic valve insufficiency, and three had a mixed disease. The Ross-Konno procedure was used for four patients. The mean cardiopulmonary bypass time was 184.68±60.1 min and the mean cross time was 149±67.8 min. One neonatal patient died in the early postoperative phase due to low cardiac output. The mean follow-up time was 60.15 ± 24.45 months. One patient later underwent reoperation due to conduit stenosis. One patient is being monitored for moderately serious conduit stenosis. At present, of those who underwent the procedure, one has moderate aortic regurgitation, two have mild or moderate aortic regurgitation, and others have minimal aortic regurgitation. No patients required intervention for left ventricular outflow tract obstruction and mortality was not observed in the long term. CONCLUSION(S): The reintervention rates for autograft and conduit-related cases were low in early and medium-term follow-up, and no significant autograft insufficiency was observed. Ross or Ross-Konno surgery is preferred for aortic diseases in pediatric patients due to its low mortality and satisfactory long-term results.

Ronald Ross: Pioneer of Malaria Research and Nobel Laureate.

Sir Ronald Ross, a British medical doctor and researcher, is renowned for his pioneering work in malaria research. His discovery of the malaria parasite's lifecycle within mosquitoes revolutionized the understanding and control of malaria, transitioning the field from the miasma theory to vector-based strategies. This literature review aims to explore the comprehensive contributions of Ronald Ross to malaria research and their enduring impact on public health.

Record of microplastic deposition revealed by ornithogenic soil and sediment profiles from Ross Island, Antarctica.

Microplastics (MPs) are a global concern as an emerging pollutant, and the investigation on MPs in Antarctic aids in informing their global pollution assessments. Therefore, there are urgent scientific concerns regarding the environmental behavior, origins, influencing factors, and potential hazards of MPs in Antarctica. This study presents the characteristics of MPs from one ornithogenic sediment profile (coded CC) and two ornithogenic soil profiles (coded MR1 and MR2) from ice-free areas on Ross Island, Antarctica. We explored the potential sources of MPs and the main influencing factors for deposition based on their distribution with depth in the profiles. Through laser-infrared imaging spectroscopy (LDIR), a total of 30 polymer types were identified in all samples, with polyethylene terephthalate (PET) and polyvinyl chloride (PVC) as the dominant types, accounting for more than 70% of the total. The abundance of MPs in the CC sediment profile ranged from 2.83 to 394.18 items/g, while in MR1 and MR2 soil profiles, the abundance ranged from 2.25 to 1690.11 and 8.24 to 168.27 items/g, respectively. The size of MPs was mainly concentrated in the range of 20-50 µm, and possible downward movement of certain polymer types was revealed. From the perspective of temporal variation, we suggest that MPs were heavily influenced by local human activities including scientific research, fishing, and tourism, balanced by protective regulations, while no solid evidence was obtained to support strong influence from biological transport through penguins. This research enhances our understanding on the environmental behavior of MPs in the terrestrial systems of remote polar regions.

The Landscape of Congenital Heart Disease Treated with the Ross Procedure.

OBJECTIVES: The Ross procedure has excellent outcomes in the pediatric population. Some series report age and anatomy dependent outcomes, but no comprehensive analysis stratified by these variables exists. We sought to describe the landscape of congenital heart disease (CHD) treated with the Ross procedure and identify the patients best served with this operation. METHODS: Over 30 years, 317 pediatric patients underwent the Ross procedure. Patients were stratified into 4 age groups: neonates (<31days,n=21), infants (31days-1year,n=40), children (1-12years,n=165), and adolescents (13-18years,n=91), and 3 anatomical groups: isolated aortic valve (AV) disease (n=221), Shone's complex or multilevel LVOT obstruction (n=61), and complex CHD (n=35). Groups were compared across outcomes. RESULTS: Neonates and infants had the highest rates of Shone's syndrome (p<0.001), complex CHD (p<0.001), concomitant root enlargement (p<0.001), and arch procedures (p<0.001). Operative mortality and morbidity were 14/317 (4.4%) and 44/317 (14%) respectively. Both were higher in neonates and infants (p<0.001,p<0.001), but lower for patients with isolated AV disease (p<0.001,p<0.001). 10-year survival and freedom from LVOT reintervention were 92% and 81% and were both significantly better in patients with isolated AV disease compared to those with complex CHD (p<0.001,p=0.005). In neonates and infants with isolated AV disease, operative mortality was 1/23 (4%), morbidity was 2/23 (9%), 10-year survival was 85.6%, and 10-year freedom from LVOT reintervention was 88.4%. CONCLUSIONS: Among pediatric patients, those with isolated AV disease are best served with the Ross procedure, regardless of age. Complex CHD is associated with lower survival and increased risk of LVOT reintervention.

Computational analysis of heart valve growth and remodeling after the Ross procedure.

During the Ross procedure, an aortic heart valve is replaced by a patient's own pulmonary valve. The pulmonary autograft subsequently undergoes substantial growth and remodeling (G&R) due to its exposure to increased hemodynamic loads. In this study, we developed a homogenized constrained mixture model to understand the observed adaptation of the autograft leaflets in response to the changed hemodynamic environment. This model was based on the hypothesis that tissue G&R aims to preserve mechanical homeostasis for each tissue constituent. To model the Ross procedure, we simulated the exposure of a pulmonary valve to aortic pressure conditions and the subsequent G&R of the valve. Specifically, we investigated the effects of assuming either stress- or stretch-based mechanical homeostasis, the use of blood pressure control, and the effect of root dilation. With this model, we could explain different observations from published clinical studies, such as the increase in thickness, change in collagen organization, and change in tissue composition. In addition, we found that G&R based on stress-based homeostasis could better capture the observed changes in tissue composition than G&R based on stretch-based homeostasis, and that root dilation or blood pressure control can result in more leaflet elongation. Finally, our model demonstrated that successful adaptation can only occur when the mechanically induced tissue deposition is sufficiently larger than tissue degradation, such that leaflet thickening overrules leaflet dilation. In conclusion, our findings demonstrated that G&R based on mechanical homeostasis can capture the observed heart valve adaptation after the Ross procedure. Finally, this study presents a novel homogenized mixture model that can be used to investigate other cases of heart valve G&R as well.

Ross Confers More Favorable Left Ventricular Remodeling Compared With Mechanical Aortic Valve Replacement.

Background: Aortic valve disease results in left ventricular (LV) dilation and/or hypertrophy. Valve intervention may improve, but not normalize flow dynamics. We hypothesized that LV remodeling would be more favorable following the Ross procedure versus mechanical aortic valve replacement (mAVR). Methods: Patients who were 18 to 50 years of age and underwent Ross or mAVR from 2000 to 2016 at a single institution were retrospectively reviewed. Propensity score matching was performed and yielded 27 well-matched pairs. Demographics and echocardiographic variables of LV morphology and wall thickness were collected. Those with > mild residual valve disease were excluded. Primary endpoints included LV morphology. T test and Fisher exact test analysis were used for statistical comparison. Results: Average age at operation (Ross 35.3 ± 10.2 vs mAVR 37.3 ± 8.9 years) did not differ. Indication for operation was similar between groups. Preoperative echocardiographic variables did not differ. At average follow-up duration (Ross 7.9 ± 2.4 vs mAVR 7.3 ± 2.4 years), wall thickness was significantly smaller for Ross compared with mAVR (P = .00715). Only 4/27 (15%) of mAVR patients had normalized LV parameters compared with 16/27 (59%) of Ross patients (P = .000813). Residual hypertrophy was the most common long-term abnormality for mAVR. Conclusion: Following aortic valve replacement with the Ross procedure or mechanical aortic valve prosthesis, the Ross conferred more favorable LV remodeling compared with mAVR. Future directions include analyzing longer follow-up to determine if patterns persist and the impact on cardiac morbidity and mortality.

Huge, invasive, and destructive Abiotrophia defectiva endocarditis of the aortic valve and the aortic wall: a case report of an emergency but successful Ross-Konno operation in a child.

Background: Abiotrophia defectiva forms Gram-positive cocci, is part of normal oropharyngeal and gastrointestinal flora, and is rarely involved in endocarditis in children population. Its special nutritional requirements and subacute clinical course may delay diagnosis and proper treatment, leading to life-threatening consequences. Case summary: We report a rare case of huge and destructive A. defectiva infective endocarditis (IE) of the aortic valve and the aortic wall in a 3-year-old child, in follow-up after surgical valvuloplasty for congenital aortic stenosis. The child presented at our department with signs of left side hemiplegia. Transthoracic echocardiography showed severe aortic regurgitation due to large vegetation extending to the aortic wall up to the aortic arch. Blood cultures resulted positive for A. defectiva. He was initially treated conservatively with antibiotic therapy. Ten days after admission, because of clinical deterioration, he required intubation and an emergency Ross-Konno operation. Despite the critical conditions and highly risky surgery, the child recovered well and was discharged home 5 weeks after the operation. Discussion: Abiotrophia defectiva IE is rare in children. Since 1995, only 16 cases of A. defectiva IE have been reported in children, including our case. This pathogen has a higher rate of complications when affecting children rather than adult population. Our case demonstrates that conservative strategy with antibiotics is rarely resolutive in the case of IE caused by A. defectiva. Whenever one or more indications for surgery are present, surgical intervention should always be taken into consideration, even if clinical conditions are prohibitive and surgery is at very high risk.

Long-term results of patients undergoing the Ross procedure after a previous aortic valve surgery.

OBJECTIVES: To assess the long-term outcomes of patients undergoing a Ross procedure in the context of a redo aortic valve (AV) surgery. METHODS: Prospectively collected data in all consecutive adults who underwent a Ross procedure were analyzed to compare the Ross procedure performed as a first surgery (RF) or as a redo surgery (RP). RESULTS: Between 1990 and 2021, 395 Ross procedures were performed at our center (RF, n = 345; RP, n = 50). A 2:1 propensity score matching was performed (RF, n = 100; RP, n = 50). The overall median follow-up was 11.6 years (interquartile range, 5.0-21.8 years) and 100% complete. Mean survival at 20 years was 87 ± 12% in the RF group and 87 ± 8% in the RP group (P = .30). The cumulative incidence of autograft reintervention at 10 years and 20 years was 6 ± 3% and 21 ± 6%, respectively, in the RF group and 9 ± 5% and 25 ± 8%, respectively, in the RP group (P = .74). The AV gradient remained stable up to 20 years in both groups (P = .42). The size of the sinuses of Valsalva tended to increase over time in the RF group but remained stable in the RP group (P = .03). CONCLUSIONS: The ross procedure after a previous sternotomy for AV surgery is safe and offers good long-term results. Patients undergoing redo AV intervention have similar results as patients undergoing a primary Ross procedure, perhaps with a lower risk of autograft dilatation.

Current and future burden of Ross River virus infection attributable to increasing temperature in Australia: a population-based study.

Background: Ross River virus (RRV), Australia's most notifiable vector-borne disease transmitted through mosquito bites, has seen increased transmission due to rising temperatures. Quantifying the burden of RRV infection attributable to increasing temperatures (both current and future) is pivotal to inform prevention strategies in the context of climate change. Methods: As RRV-related deaths are rare in Australia, we utilised years lived with disability (YLDs) associated with RRV infection data from the Australian Institute of Health and Welfare (AIHW) Burden of Disease database between 2003 and 2018. We obtained relative risks per 1 °C temperature increase in RRV infection from a previous meta-analysis. Exposure distributions for each Köppen-Geiger climate zone were calculated separately and compared with the theoretical-minimum-risk exposure distribution to calculate RRV burden attributable to increasing temperatures during the baseline period (2003-2018), and projected future burdens for the 2030s and 2050s under two greenhouse gas emission scenarios (Representative Concentration Pathways, RCP 4.5 and RCP 8.5), two adaptation scenarios, and different population growth series. Findings: During the baseline period (2003-2018), increasing mean temperatures contributed to 35.8 (±0.5) YLDs (19.1%) of the observed RRV burden in Australia. The mean temperature attributable RRV burden varied across climate zones and jurisdictions. Under both RCP scenarios, the projected RRV burden is estimated to increase in the future despite adaptation scenarios. By the 2050s, without adaptation, the RRV burden could reach 45.8 YLDs under RCP4.5 and 51.1 YLDs under RCP8.5. Implementing a 10% adaptation strategy could reduce RRV burden to 41.8 and 46.4 YLDs, respectively. Interpretation: These findings provide scientific evidence for informing policy decisions and guiding resource allocation for mitigating the future RRV burden. The current findings underscore the need to develop location-specific adaptation strategies for climate-sensitive disease control and prevention. Funding: Australian Research Council Discovery Program.

New distributional records of Southern Ocean Isopoda based on vouchers from the Italian National Antarctic Museum (MNA, Section of Genoa).

Background: The order Isopoda Latreille, 1816 consists of species occurring in terrestrial, marine and freshwater environments. In the Southern Ocean (SO), this group is amongst the most speciose and occur at all depths. Isopoda biogeography, despite being studied since the first Antarctic expeditions, is still poorly known from a geographical point of view and shows large occurrence gaps for some groups in specific sectors of the SO. In this paper, we update the isopod checklists of the Ross Sea (RS) and of some peri-Antarctic areas, such as the South Orkney Islands (SOI) and the South Sandwich Islands (SSI), based on the study of museum vouchers curated by the Italian National Antarctic Museum (MNA, Section of Genoa). New information: A total of 279 MNA samples from 15 different expeditions were studied. From this material, consisting of 419 specimens, 41 accepted species distributed in 24 families and 51 genera were identified. Comparing this newly-obtained information with the GBIF (Global Biodiversity Information Facility) and OBIS (Ocean Biodiversity Information System) portal, 15 species are here reported for the first time in the Ross Sea, with five new records in the Ross Sea Marine Protected Area. All records are new for the Terra Nova Bay area, for which a checklist of this group has never been produced before.

Viromes of Antarctic fish resemble the diversity found at lower latitudes.

Antarctica harbours some of the most isolated and extreme environments on Earth, concealing a largely unexplored and unique component of the global animal virosphere. To understand the diversity and evolutionary histories of viruses in these polar species, we determined the viromes of gill metatranscriptomes from 11 Antarctic fish species with 248 samples collected from the Ross Sea region spanning the Perciformes, Gadiformes, and Scorpaeniformes orders. The continent's shift southward and cooling temperatures >20 million years ago led to a reduction in biodiversity and subsequent radiation of some marine fauna, such as the notothenioid fishes. Despite decreased host species richness in polar regions, we revealed a surprisingly complex virome diversity in Ross Sea fish, with the types and numbers of viruses per host species and individuals sampled comparable to that of fish in warmer marine environments with higher host community diversity. We also observed a higher number of closely related viruses likely representing instances of recent and historic host-switching events among the Perciformes (all notothenioids) than in the Gadiformes, suggesting that rapid speciation events within this order generated closely related host species with few genetic barriers to cross-species transmission. Additionally, we identified novel genomic variation in an arenavirus with a split nucleoprotein sequence containing a stable helical structure, indicating potential adaptation of viral proteins to extreme temperatures. These findings enhance our understanding of virus evolution and virus-host interactions in response to environmental shifts, especially in less diverse ecosystems that are more vulnerable to the impacts of anthropogenic and climate changes.

The Fate of the Left Ventricular Outflow Tract Following Interrupted Aortic Arch Repair.

Objectives: To examine the probability of left ventricular outflow tract (LVOT) reintervention following interrupted aortic arch (IAA) repair in neonates with LVOT obstruction (LVOTO) risk. Methods: This retrospective multicenter study included 150 neonates who underwent IAA repair (2003-2017); 100 of 150 (67%) had isolated IAA repair (with ventricular septal defect closure) and 50 of 150 (33%) had concomitant LVOT intervention: conal muscle resection (n = 16), Ross-Konno (n = 7), and Yasui operation (n = 27: single-stage n = 8, staged n = 19). Demographic and morphologic characteristics were reviewed. Factors associated with LVOT reoperation were explored using multivariable analysis. Results: Concomitant LVOT intervention was more likely in neonates with type B IAA, bicuspid aortic valve, aberrant right subclavian artery, smaller aortic valve annulus, and ascending aorta dimensions. On follow-up, five-year freedom from LVOT reoperation was highest following Ross-Konno (100%), 77% following Yasui (mainly for neo-aortic regurgitation), 77% following isolated IAA repair (mainly for LVOTO), and 47% following IAA repair with concomitant conal resection, P = .033. While all patients had low peak LVOT gradient at time of discharge, those who had conal resection developed higher gradients on follow-up (P = .007). Ross-Konno and Yasui procedures were associated with higher right ventricular outflow tract (RVOT) reoperation. In the cohort following isolated IAA repair, aortic sinus Z score was associated with LVOT reoperation. Conclusions: Both Yasui and Ross-Konno operations effectively mitigate late LVOTO risk. The highest risk of reintervention for LVOTO was associated with conal muscle resection while the lowest risk is associated with Ross-Konno. The RVOT reoperation risk in patients who had Ross-Konno or Yasui does not seem to affect survival.

Chemical threats for the sentinel Pygoscelis adeliae from the Ross Sea (Antarctica): Occurrence and levels of persistent organic pollutants (POPs), perfluoroalkyl substances (PFAS) and mercury within the largest marine protected area worldwide.

The Ross Sea Marine Protected Area (RS-MPA) hosts endemic species that have to cope with multiple threats, including chemical contamination. Adèlie penguin is considered a good sentinel species for monitoring pollutants. Here, 23 unhatched eggs, collected from three colonies along the Ross Sea coasts, were analysed to provide updated results on legacy pollutants and establish a baseline for newer ones. Average sum of polychlorinated biphenyls (∑PCBs) at the three colonies ranged 20.9-24.3 ng/g lipid weight (lw) and included PCBs IUPAC nos. 28, 118, 153, 138, 180. PCBs were dominated by hexachlorinated congeners as previously reported. Hexachlorobenzene (HCB) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) ranged between 134 and 166 and 181-228 ng/g lw, respectively. Overall, ∑PCBs was exceeded by pesticides, contrary to previous studies from the Ross Sea. Sum of polybrominated diphenyl ethers (∑PBDEs) ranged between 0.90 and 1.18 ng/g lw and consisted of BDE-47 (that prevailed as expected, representing 60-80 % of the ∑PBDEs) and BDE-85. Sum of perfluoroalkyl substances (∑PFAS) ranged from 1.04 to 1.53 ng/g wet weight and comprised five long-chain perfluorinated carboxylic acids (PFCAs), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA); perfluorooctane sulfonamide (PFOSA) was also detected. The PFAS profile was dominated by PFCAs as already observed in Arctic seabirds. Mercury ranged from 0.07 to 0.15 mg/kg dry weight similarly to previous studies. Legacy pollutants confirmed their ongoing presence in Antarctic biota and their levels seemed mostly in line with the past, but with minor variations in some cases, likely due to continued input or release from past reservoirs. PFAS were reported for the first time in penguins from the Ross Sea, highlighting their ubiquity. Although further studies would be useful to increase the sample size and accordingly improve our knowledge on spatial and temporal trends, this study provides interesting data for future monitoring programs within the RS-MPA that will be crucial to test its effectiveness against human impacts.

Novel Techniques and Technologies for Surgical Aortic Valve Replacement: A Large Retrospective Cohort Analysis.

Background/Objectives: In an era of growing evidence for transaortic valve implantation (TAVI), our research topic was the evaluation of how surgical aortic valve replacements (SAVRs) are performing in terms of short- and long-term outcomes in different risk categories. Methods: This was a single centre, prospective, and observational cohort study of consecutive patients with aortic valve stenosis, undergoing isolated aortic valve replacement using a biological or mechanical prosthesis, Freestyle™ (Medtronic, Minneapolis, MN, USA) graft, homograft, or Ross procedure. The participant data were collected by review of an internal database. The primary endpoints were all-cause operative mortality (in hospital and at 30 days) and late mortality at the follow-up date. The secondary composite endpoint was the incidence of postoperative complications. Results: 1501 patients underwent SAVR; the mean age was 67 years (SD: 12.6). The in-hospital mortality was 1% (n = 16). At a median follow-up of 60 months, the survival rate was 98.7%. The main predictors for mortality were operative urgency and cardiogenic shock. The overall incidence of PPM was 2.3% (n = 34). Patients who underwent Ross procedure were younger (mean age: 20 years (SD: 1.7)), had a lower incidence of postoperative complications, and were all alive at follow-up. Conclusions: SAVR shows an excellent survival rate and a low rate of postoperative complications despite an increasing surgical risk. Recent advancements in technology, like sutureless/rapid deployment prostheses and minimally invasive techniques, are shown to have favourable effects on outcomes.

Long-term outcome after the Ross procedure in 173 adults with up to 25 years of follow-up.

OBJECTIVES: The potential risk of autograft dilatation and homograft stenosis after the Ross procedure mandates lifelong follow-up. This retrospective cohort study aimed to determine long-term outcome of the Ross procedure, investigating autograft and homograft failure patterns leading to reintervention. METHODS: All adults who underwent the Ross procedure between 1991 and 2018 at the University Hospitals Leuven were included, with follow-up data collected retrospectively. Autograft implantation was performed using the full root replacement technique. The primary end-point was long-term survival. Secondary end-points were survival free from any reintervention, autograft or homograft reintervention-free survival, and evolution of autograft diameter, homograft gradient and aortic regurgitation grade over time. RESULTS: A total of 173 adult patients (66% male) with a median age of 32 years (range 18-58 years) were included. External support at both the annulus and sinotubular junction was used in 38.7% (67/173). Median follow-up duration was 11.1 years (IQR, 6.4-15.9; 2065 patient-years) with 95% follow-up completeness. There was one (0.6%) perioperative death. Kaplan-Meier estimate for 15-year survival was 91.1% and Ross-related reintervention-free survival was 75.7% (autograft: 83.5%, homograft: 85%). Regression analyses demonstrated progressive neoaortic root dilatation (0.56 mm/year) and increase in homograft gradient (0.72 mmHg/year). CONCLUSIONS: The Ross procedure has the potential to offer excellent long-term survival and reintervention-free survival. These long-term data further confirm that the Ross procedure is a suitable option in young adults with aortic valve disease which should be considered on an individual basis.

Long-term outcomes following the Ross procedure in neonates and infants: A multi-institutional analysis.

OBJECTIVES: For neonates and infants with aortic valve pathology, the Ross procedure historically has been associated with high rates of morbidity and mortality. Data regarding long-term durability are lacking. METHODS: The international, multi-institutional Ross Collaborative included 6 tertiary care centers. Infants who underwent a Ross operation between 1996 and 2016 (allowing a minimum 5 years of follow-up) were retrospectively identified. Serial echocardiograms were examined to study evolution in neoaortic size and function. RESULTS: Primary diagnoses for the 133 patients (n = 30 neonates) included isolated aortic stenosis (14%, n = 19), Shone complex (14%, n = 19), and aortic stenosis plus other (excluding Shone complex; n = 95, 71%), including arch obstruction (n = 55), left ventricular hypoplasia (n = 9), and mitral disease (moderate or greater stenosis or regurgitation, n = 31). At the time of the Ross procedure, median age was 96 days (interquartile range, 36-186), and median weight was 4.4 kg (3.6-6.5). In-hospital mortality occurred in 13 of 133 patients (10%) (4/30 [13%] neonates). Postdischarge mortality occurred in 10 of 120 patients (8%) at a median of 298 days post-Ross. Post-Ross neoaortic dilatation occurred, peaking at 4 to 5 SDs above normal at 2 to 3 years before returning to near-baseline z-score at a median follow-up of 11.5 [6.4-17.4] years. Autograft/left ventricular outflow tract reintervention was required in 5 of 120 patients (4%) at a median of 10.3 [4.1-12.8] years. Freedom from moderate or greater neoaortic regurgitation was 86% at 15 years. CONCLUSIONS: Neonates and infants experience excellent postdischarge survival and long-term freedom from autograft reintervention and aortic regurgitation after the Ross. Neoaortic dilatation normalizes in this population in the long-term. Increased consideration should be given to Ross in neonates and infants with aortic valve disease.

Synoviocytes assist in modulating the effect of Ross River virus infection in micromass-cultured primary human chondrocytes.

Introduction. Ross River virus (RRV) is a mosquito-borne virus prevalent in Australia and the islands of the South Pacific, where it causes an arthritogenic illness with a hallmark feature of severe joint pain. The joint space is a unique microenvironment that contains cartilage and synovial fluid. Chondrocytes and synoviocytes are crucial components of the joint space and are known targets of RRV infection.Hypothesis/Gap statement. Understanding the relationship between synoviocytes and chondrocytes during RRV infection will provide further insights into RRV-induced joint pathology.Methodology. To better understand the unique dynamics of these cells during RRV infection, we used primary chondrocytes cultured in physiologically relevant micromasses. We then directly infected micromass chondrocytes or infected primary fibroblast-like synoviocytes (FLS), co-cultured with micromass chondrocytes. Micromass cultures and supernatants were collected and analysed for viral load with a PCR array of target genes known to play a role in arthritis.Results. We show that RRV through direct or secondary infection in micromass chondrocytes modulates the expression of cellular factors that likely contribute to joint inflammation and disease pathology, as well as symptoms such as pain. More importantly, while we show that RRV can infect micromass-cultured chondrocytes via FLS infection, FLS themselves affect the regulation of cellular genes known to contribute to arthritis.Conclusion. Single-cell culture systems lack the complexity of in vivo systems, and understanding the interaction between cell populations is crucial for deciphering disease pathology, including for the development of effective therapeutic strategies.

Comprehensive Metagenomic Analysis of Veterinary Probiotics in Broiler Chickens.

Probiotics are widely used in broiler chickens to support the gut microbiome, gut health, and to reduce the amount of antibiotics used. Despite their benefits, there is concern over their ability to carry and spread antimicrobial resistance genes (ARGs), posing a significant public health risk. This study utilized next-generation sequencing to investigate ARGs in probiotics approved for poultry, focusing on their potential to be transferred via mobile genetic elements such as plasmids and phages. We examined the gut microbiome and resistome changes in 60 broiler chickens over their rearing period, correlating these changes with different probiotic treatments. Specific resistance mechanisms against critically important antibiotics were identified, including genes related to fluoroquinolone resistance and peptide antibiotic resistance. We also found genes with significant relevance to public health (aadK, AAC(6')-Ii) and multiple drug-resistance genes (vmlR, ykkC, ykkD, msrC, clbA, eatAv). Only one phage-encoded gene (dfrA43) was detected, with no evidence of plasmid or mobile genetic element transmission. Additionally, metagenomic analysis of fecal samples showed no significant changes corresponding to time or diet across groups. Our findings highlight the potential risks associated with the use of probiotics in poultry, particularly regarding the carriage of ARGs. It is crucial to conduct further research into the molecular genetics of probiotics to develop strategies that mitigate the risk of resistance gene transfer in agriculture, ensuring the safe and effective use of probiotics in animal husbandry.