Elucidating supercritical fluid extraction of fucoxanthin from algae to enable the integrated biorefinery.

The emerging nutraceutical, fucoxanthin, shows promise as a high-value product to enable the integrated biorefinery. Fucoxanthin can be extracted from algae through supercritical fluid extraction (SFE), but literature does not agree on optimal extraction conditions. Here, a statistical analysis of literature identifies supercritical carbon dioxide (scCO2) density, ethanol cosolvent amount, and polarity as significant predictors of fucoxanthin yield. Novel SFE experiments are then performed using a fucoxanthin standard, describing its fundamental solubility. These experiments establish solvent system polarity as the key knob to tune fucoxanthin recovery from 0% to 100% and give specific operating conditions for targeted fucoxanthin extraction.Further experiments compare extractions on fucoxanthin standard with extractions from Phaeodactylum tricornutum microalgae to elucidate the effect of the algae matrix. Results show selectivity of fucoxanthin over chlorophyll in scCO2 microalgae extractions that was not seen in extractions with ethanol, indicating a benefit of scCO2 to design selective extraction schemes.

A pilot study to develop assessment tools for Group A Streptococcus surveillance studies.

Introduction: Group A Streptococcus (GAS) causes pharyngitis (sore throat) and impetigo (skin sores) GAS pharyngitis triggers rheumatic fever (RF) with epidemiological evidence supporting that GAS impetigo may also trigger RF in Australian Aboriginal children. Understanding the concurrent burden of these superficial GAS infections is critical to RF prevention. This pilot study aimed to trial tools for concurrent surveillance of sore throats and skins sore for contemporary studies of RF pathogenesis including development of a sore throat checklist for Aboriginal families and pharynx photography. Methods: Yarning circle conversations and semi-structured interviews were performed with Aboriginal caregivers and used to develop the language and composition of a sore throat checklist. The sore throat story checklist was combined with established methods of GAS pharyngitis and impetigo surveillance (examination, bacteriological culture, rapid antigen detection and serological tests) and new technologies (photography) and used for a pilot cross-sectional surveillance study of Aboriginal children attending their health clinic for a routine appointment. Feasibility, acceptability, and study costs were compiled. Results: Ten Aboriginal caregivers participated in the sore-throat yarning circles; a checklist was derived from predominant symptoms and their common descriptors. Over two days, 21 Aboriginal children were approached for the pilot surveillance study, of whom 17 were recruited; median age was 9 years [IQR 5.5-13.5], 65% were female. One child declined throat swabbing and three declined finger pricks; all other surveillance elements were completed by each child indicating high acceptability of surveillance assessments. Mean time for screening assessment was 19 minutes per child. Transport of clinical specimens enabled gold standard microbiological and serological testing for GAS. Retrospective examination of sore throat photography concorded with assessments performed on the day. Conclusion: Yarning circle conversations were effective in deriving culturally appropriate sore throat questionnaires for GAS pharyngitis surveillance. New and established tools were feasible, practical and acceptable to participants and enable surveillance to determine the burden of superficial GAS infections in communities at high risk of RF. Surveillance of GAS pharyngitis and impetgio in remote Australia informs primary RF prevention with potential global translation.

What to Expect When Expecting in Lab: A Review of Unique Risks and Resources for Pregnant Researchers in the Chemical Laboratory.

Pregnancy presents a unique risk to chemical researchers due to their occupational exposures to chemical, equipment, and physical hazards in chemical research laboratories across science, engineering, and technology disciplines. Understanding "risk" as a function of hazard, exposure, and vulnerability, this review aims to critically examine the state of the science for the risks and associated recommendations (or lack thereof) for pregnant researchers in chemical laboratories (labs). Commonly encountered hazards for pregnant lab workers include chemical hazards (organic solvents, heavy metals, engineered nanomaterials, and endocrine disruptors), radiation hazards (ionizing radiation producing equipment and materials and nonionizing radiation producing equipment), and other hazards related to the lab environment (excessive noise, excessive heat, psychosocial stress, strenuous physical work, and/or abnormal working hours). Lab relevant doses and routes of exposure in the chemical lab environment along with literature and governmental recommendations or resources for exposure mitigation are critically assessed. The specific windows of vulnerability based on stage of pregnancy are described for each hazard, if available. Finally, policy gaps for further scientific research are detailed to enhance future guidance to protect pregnant lab workers.

Myocardial deformation assessed by CMR in children after multisystem inflammatory syndrome (MIS-C).

BACKGROUND: Short-term sequelae of Multisystem Inflammatory Syndrome in Children (MIS-C), recently published by our institution, showed rapid improvement of the cardiac abnormalities within a few weeks after the onset of the disease. However, subtle residual abnormalities, affecting mainly the myocardial interstitium, were shown in some of the patients. The current study aimed to assess myocardial deformation with CMR shortly after MIS-C. METHODS: Sixty children were included into the study; 30 following MIS-C (onset-to-scan mean 27 days, SD 11) and 30 controls. Strain values were compared between patients and controls and additionally to published paediatric normal CMR values. U-Mann Whitney test was used for comparison of the myocardial deformation between patients and controls. RESULTS: Median age of the patients was 9.0 years (range 0.99-14.4) and controls 9.8 years (range 4.7-14.9). All conventional CMR parameters in patients were in normal range. Strain values were significantly lower in patients than in controls. When compared to published centile graphs, radial and circumferential global strain was within 2.5th and 97.5th centile in all patients. Eleven patients had global longitudinal strain between 2.5th centile and 50th centile, 1 patient was below 2.5th centile and all the others above 50th centile. Only 3 controls had global longitudinal strain between 2.5th centile and 50th centile, all other had higher strain. CONCLUSIONS: This study demonstrates that myocardial deformation indices measured by CMR are within normal range in the vast majority of the patients within a few weeks after the onset of MIS-C. However, when compared to healthy controls, all strain parameters were lower in patients.

Conducting decolonizing research and practice with Australian First Nations to close the health gap.

The purpose of this paper is to highlight a perspective for decolonizing research with Australian First Nations and provide a framework for successful and sustained knowledge translation by drawing on the recent work conducted by a research group, in five remote communities in North-Western Australia. The perspective is discussed in light of national and international calls for meaningful and dedicated engagement with First Nations people in research, policy and practice, to help close the health gap between First Nations and other Australians.

First reported outbreak of the emerging pathogen Candida auris in Canada.

BACKGROUND: Candida auris was first described in Japan in 2009 and has since been detected in over 40 countries. The yeast is concerning for multiple reasons, primarily: (1) challenges with accurate identification; (2) reported multidrug resistance; (3) published mortality rates of 30%-60%; and (4) persistence in the environment associated with human transmission. We report the emergence of a healthcare-associated cluster in the Greater Vancouver area in 2018 and describe the measures implemented to contain its transmission. METHODS: Cases were identified through passive and ring surveillance of affected wards. Positive isolates were sent to provincial and national reference laboratories for confirmation and genomic characterization. Extensive infection control measures were implemented immediately after the initial case was identified. RESULTS: Four cases were identified during the outbreak. In a 4-month period, over 700 swabs were collected in order to screen 180 contacts. Whole genome sequencing concluded that all isolates clustered together and belonged to the South Asian clade. No isolates harbored FKS gene mutations associated with resistance to echinocandins. Infection control measures, including surveillance, education, cleaning and/or disinfection, patient cohorting, isolation, and hand hygiene, effectively contained the outbreak; it was declared over within 2 months. CONCLUSIONS: The spread of C auris in healthcare facilities has not spared Canadian institutions. Our experience demonstrates that strict infection control measures combined with microbiological screening can effectively halt transmission in healthcare centers. The necessity of active prospective screening remains unclear.

On-Campus Clinical: Preparing Prelicensure Nursing Students for a Safe Clinical Practice.

BACKGROUND: Ensuring students are both confident and competent for clinical practice will lead to improved patient outcomes. Early exposure to delivering safe and effective care using knowledge, skills, and abilities that are consonant with professional practice is essential. PROBLEM: Caring for an increasingly complex patient population is challenging. Entry-to-practice competencies must begin early in the student's education and be developed throughout. APPROACH: This educational initiative outlines an innovative and a collaborative evidence-based learning experience that prepares prelicensure nursing students to deliver safe and effective patient-centered care during their first clinical practice. Lecture and laboratory topics, clinical skills stations, and simulation scenarios were developed to promote critical thinking and clinical judgment in a complex health care environment. OUTCOMES: More than 2300 first-year clinical students, instructors, and staff participated in this rigorous course-wide experience. CONCLUSION: This 1-day immersion cultivates safe practice and may be incorporated throughout the curriculum as students encounter increasingly challenging clinical practice experiences.

Recognition and Management of Protracted Bacterial Bronchitis in Australian Aboriginal Children: A Knowledge Translation Approach.

BACKGROUND: Chronic wet cough in children is the hallmark symptom of protracted bacterial bronchitis (PBB) and if left untreated can lead to bronchiectasis, which is prevalent in Indigenous populations. Underrecognition of chronic wet cough by parents and clinicians and underdiagnosis of PBB by clinicians are known. RESEARCH QUESTION: We aimed to improve recognition and management of chronic wet cough in Aboriginal children using knowledge translation (KT), a methodologic approach that can be adapted for use in Indigenous contexts to facilitate effective and sustained translation of research into practice. STUDY DESIGN AND METHODS: A mixed-methods KT study undertaken at a remote-based Aboriginal primary medical service (February 2017 to December 2019). Our KT strategy included the following: (1) culturally secure (ie, ensuring Aboriginal people are treated regarding their unique cultural needs and differences) knowledge dissemination to facilitate family health seeking for chronic wet cough in children, and (2) an implementation strategy to facilitate correct diagnosis and management of chronic wet cough and PBB by physicians. RESULTS: Post-KT, health seeking for chronic wet cough increased by 184% (pre = eight of 630 children [1.3%], post = 23 of 636 children [3.6%]; P = .007; 95% CI, 0.7%-4.0%). Physician proficiency in management of chronic wet cough improved significantly as reflected by improved chronic cough-related quality of life (P < .001; 95% CI, 0.8-3.0) and improved physician assessment of cough quality (P < .001; 95% CI, 10.4%-23.0%), duration (P < .001; 95% CI, 11.1%-24.1%), and appropriate antibiotic prescription (P = .010; 95% CI, 6.6%-55.7%). INTERPRETATION: Health seeking for children with chronic wet cough can be facilitated through provision of culturally secure health information. Physician proficiency in the management of PBB can be improved with KT strategies which include training in culturally informed management, leading to better health outcomes. Comprehensive strategies that include both families and health systems are required to ensure that chronic wet cough in children is detected and optimally managed.

Toward Informed Design of Nanomaterials: A Mechanistic Analysis of Structure-Property-Function Relationships for Faceted Nanoscale Metal Oxides.

Nanoscale metal oxides (NMOs) have found wide-scale applicability in a variety of environmental fields, particularly catalysis, gas sensing, and sorption. Facet engineering, or controlled exposure of a particular crystal plane, has been established as an advantageous approach to enabling enhanced functionality of NMOs. However, the underlying mechanisms that give rise to this improved performance are often not systematically examined, leading to an insufficient understanding of NMO facet reactivity. This critical review details the unique electronic and structural characteristics of commonly studied NMO facets and further correlates these characteristics to the principal mechanisms that govern performance in various catalytic, gas sensing, and contaminant removal applications. General trends of facet-dependent behavior are established for each of the NMO compositions, and selected case studies for extensions of facet-dependent behavior, such as mixed metals, mixed-metal oxides, and mixed facets, are discussed. Key conclusions about facet reactivity, confounding variables that tend to obfuscate them, and opportunities to deepen structure-property-function understanding are detailed to encourage rational, informed design of NMOs for the intended application.

Transcatheter Closure of Patent Ductus Arteriosus in Infants With Weight Under 1,500 Grams.

Persistent patent ductus arteriosus (PDA) is very common in preterm infants, especially in extremely preterm infants. Despite significant advances in management of these vulnerable infants, there has been no consensus on management of PDA-when should we treat, who should we treat, how should we treat and in fact there is no agreement on how we should define a hemodynamically significant PDA. Medical management with non-steroidal anti-inflammatory drugs (NSAIDs) remains the first line of therapy with moderate success rate in closing the PDA. Paracetamol has been reported to be a safe and equally effective medical therapy for closure of PDA. However, additional studies on its long-term safety and efficacy in extremely low birth weight infants are needed before paracetamol can be recommended as standard treatment for a PDA in preterm infants. Surgical ligation of PDA is not without an increased risk of mortality and co-morbidities. Recently, there has been a significant interest in percutaneous transcatheter closure of PDA in preterm infants, including extremely low birth weight infants. Transcatheter PDA closure in preterm ELBW infants is technically feasible with high PDA occlusion success rates and acceptable complication rates as compared to surgical ligation. Many centers have reported promising early- and mid-term follow-up results. However, they need to be further tested in the prospective well-designed studies and randomized controlled trials comparing the results and outcomes of this technique with current treatment strategies including medical treatment before they can be used as the new standard of care for PDA closure in extremely low birth weight infants.

We won't find what we don't look for: Identifying barriers and enablers of chronic wet cough in Aboriginal children.

BACKGROUND AND OBJECTIVE: Chronic lung disease is prevalent among Australian Aboriginal children. Chronic wet cough is an early marker of disease but often goes undetected. Currently, no studies have examined health practitioner knowledge of chronic wet cough. We set out to examine health practitioner knowledge of chronic wet cough and chronic lung disease in Aboriginal children and to identify barriers and enablers to effective management. METHOD: A qualitative study, gathering data through individual semi-structured, in-depth interviews and focus groups to ascertain health practitioner knowledge about management of Aboriginal children with chronic wet cough in a regional Kimberley town and remote community. RESULTS: Thirty-seven health practitioners participated. Key barriers identified were: (i) limited training in assessment and management of chronic wet cough; (ii) prioritization of acute presentations and competing complex chronic conditions; and (iii) normalization of cough in children by health practitioners. Key enablers were: (i) improving practitioners' knowledge and expertise in managing chronic wet cough; and (ii) health system changes to facilitate longitudinal patient care, improved cultural competence, improved chronic disease management and post-hospitalization follow-up. CONCLUSION: Key barriers to effective management of chronic wet cough are limited training in chronic wet cough management combined with competing complexities of both acute and chronic healthcare needs for Aboriginal families. Early detection and management of chronic wet cough in Aboriginal children can be facilitated through health practitioner training, access to standardized management guidelines and a service model that allows longitudinal patient follow-up and resources to effectively prevent and manage chronic lung disease in children.

Chronic wet cough in Aboriginal children: It's not just a cough.

AIM: Chronic respiratory disease is common among Aboriginal Australians. Chronic wet cough is an early marker of chronic disease in children but often goes undetected due, in part, to delayed health seeking by families. Currently, no studies have examined the reasons for delayed health seeking for children's chronic cough. To identify the barriers to, and enablers for, seeking medical help for chronic wet cough in Aboriginal children. METHODS: This was a qualitative study, gathering data through individual semi-structured, in-depth interviews and focus groups to ascertain Aboriginal family knowledge, attitudes and beliefs about seeking health care for chronic wet cough in children in a regional Kimberley town, Western Australia between October 2017 and March 2018. RESULTS: Forty Aboriginal community members participated. The three key barriers identified were: 'Cough normalisation', that is, 70% of participants considered chronic cough normal (with 53% of participants' previous interactions with doctors informing their understanding of chronic cough); the lack of health literacy information; and a sense of disempowerment (belief that no medical action would be taken and inability to challenge doctors). The key expressed enablers were provision of health literacy information and health practitioner training to assess and treat chronic wet cough in children. All participants reported that they would seek help for chronic wet cough once they were informed that it could signify underlying disease. CONCLUSION: Results highlight the need for a culturally appropriate information and education to inform Aboriginal families and their health practitioners of the importance of chronic wet cough in children.

Mitigating Latent Threats Identified through an Embedded In Situ Simulation Program and Their Comparison to Patient Safety Incidents: A Retrospective Review.

OBJECTIVE: To assess the impact of service improvements implemented because of latent threats (LTs) detected during in situ simulation. DESIGN: Retrospective review from April 2008 to April 2015. SETTING: Paediatric Intensive Care Unit in a specialist tertiary hospital. INTERVENTION: Service improvements from LTs detection during in situ simulation. Action plans from patient safety incidents (PSIs). MAIN OUTCOME MEASURES: The quantity, category, and subsequent service improvements for LTs. The quantity, category, and subsequent action plans for PSIs. Similarities between PSIs and LTs before and after service improvements. RESULTS: 201 Simulated inter-professional team training courses with 1,144 inter-professional participants. 44 LTs were identified (1 LT per 4.6 courses). Incident severity varied: 18 (41%) with the potential to cause harm, 20 (46%) that would have caused minimal harm, and 6 (13%) that would have caused significant temporary harm. Category analysis revealed the majority of LTs were resources (36%) and education and training (27%). The remainder consisted of equipment (11%), organizational and strategic (7%), work and environment (7%), medication (7%), and systems and protocols (5%). 43 service improvements were developed: 24 (55%) resources/equipment; 9 (21%) educational; 6 (14%) organizational changes; 2 (5%) staff communications; and 2 (5%) guidelines. Four (9%) service improvements were adopted trust wide. 32 (73%) LTs did not recur after service improvements. 24 (1%) of 1,946 PSIs were similar to LTs: 7 resource incidents, 7 catastrophic blood loss, 4 hyperkalaemia arrests, 3 emergency buzzer failures, and 3 difficulties contacting staff. 34 LTs (77%) were never recorded as PSIs. CONCLUSION: An in situ simulation program can identify important LTs which traditional reporting systems miss. Subsequent improvements in workplace systems and resources can improve efficiency and remove error traps.

Impact of an open-chest extracorporeal membrane oxygenation model for in situ simulated team training: a pilot study.

OBJECTIVES: To develop an affordable realistic open-chest extracorporeal membrane oxygenation (ECMO) model for embedded in situ interprofessional crisis resource management training in emergency management of a post-cardiac surgery child. METHODS: An innovative attachment to a high-fidelity mannequin (Laerdal Simbaby) was used to enable a cardiac tamponade/ECMO standstill scenario. Two saline bags with blood dye were placed over the mannequin's chest. A 'heart' bag with venous and arterial outlets was connected to the corresponding tubes of the ECMO circuit. The bag was divided into arterial and venous parts by loosely wrapping silicon tubing around its centre. A 'pericardial' bag was placed above it. Both were then covered by a chest skin that had a sutured silicone membrane window. False blood injected into the 'pericardial' bag caused expansion leading to (i) bulging of silastic membrane, simulating tamponade, and (ii) compression of tubing around the 'heart' bag, creating negative venous pressures and cessation of ECMO flow. In situ Simulation Paediatric Resuscitation Team Training (SPRinT) was performed on paediatric intensive care unit; the course included a formal team training/scenario of an open-chest ECMO child with acute cardiac tamponade due to blocked chest drains/debriefing by trained facilitators. RESULTS: Cardiac tamponade was reproducible, and ECMO flow/circuit pressure changes were effective and appropriate. There were eight participants: one cardiac surgeon, two intensivists, one cardiologist, one perfusionist and three nurses. Five of the eight reported the realism of the model and 6/8 the realism of the clinical scenario as highly effective. Eight of eight reported a highly effective impact on (i) their practice and (ii) teamwork. Six of eight reported a highly effective impact on communication skills and increased confidence in attending future real events. CONCLUSIONS: Innovative adaptation of a high-fidelity mannequin for open-chest ECMO simulation can achieve a realistic and reproducible training model. The impact on interprofessional team training is promising but needs to be validated further.

Reliability of team-based self-monitoring in critical events: a pilot study.

BACKGROUND: Teamwork is a critical component during critical events. Assessment is mandatory for remediation and to target training programmes for observed performance gaps. METHODS: The primary purpose was to test the feasibility of team-based self-monitoring of crisis resource management with a validated teamwork assessment tool. A secondary purpose was to assess item-specific reliability and content validity in order to develop a modified context-optimised assessment tool.We conducted a prospective, single-centre study to assess team-based self-monitoring of teamwork after in-situ inter-professional simulated critical events by comparison with an assessment by observers. The Mayo High Performance Teamwork Scale (MHPTS) was used as the assessment tool with evaluation of internal consistency, item-specific consensus estimates for agreement between participating teams and observers, and content validity. RESULTS: 105 participants and 58 observers completed the MHPTS after a total of 16 simulated critical events over 8 months. Summative internal consistency of the MHPTS calculated as Cronbach's alpha was acceptable with 0.712 for observers and 0.710 for participants. Overall consensus estimates for dichotomous data (agreement/non-agreement) was 0.62 (Cohen's kappa; IQ-range 0.31-0.87). 6/16 items had excellent (kappa > 0.8) and 3/16 good reliability (kappa > 0.6). Short questions concerning easy to observe behaviours were more likely to be reliable. The MHPTS was modified using a threshold for good reliability of kappa > 0.6. The result is a 9 item self-assessment tool (TeamMonitor) with a calculated median kappa of 0.86 (IQ-range: 0.67-1.0) and good content validity. CONCLUSIONS: Team-based self-monitoring with the MHPTS to assess team performance during simulated critical events is feasible. A context-based modification of the tool is achievable with good internal consistency and content validity. Further studies are needed to investigate if team-based self-monitoring may be used as part of a programme of assessment to target training programmes for observed performance gaps.

A comparison of three methods that assess tracheal tube leakage: leak conductance, fractional volume loss, and audible assessment.

BACKGROUND: When intubating a child's trachea with an uncuffed tracheal tube (TT), it is current practice in anesthesia and intensive care to use the leak test to assess TT fit. The aim of this study is to compare three measures of assessing leak around uncuffed tracheal tubes in the PICU. METHODS: We obtained institutional ethical permission and written informed consent, prior to any clinical investigation, from the parents of 135 children who had surgery for cardiac defects. On admission to the PICU, we measured leak by audible assessment, fractional volume loss, and leak conductance for each patient. Measurements of fractional volume loss and leak conductance were repeated every 4 h thereafter until extubation. RESULTS: On admission to the PICU, calculated values of leak conductance were significantly different between each grade of audible leak (P < 0.001). Values of fractional volume loss were not significantly different between 'no leak' and 'small leak' grades of leak. Throughout the PICU stay, a significant correlation between mean leak conductance and mean fractional volume loss was found (0.86, 95% CI, 0.81-0.90). Significant agreement within time series of leak conductance and fractional volume recorded for each patient occurred in 47/128 cases (37%). CONCLUSIONS: On admission to the PICU, values of leak conductance are more strongly associated with audible assessment than with fractional volume loss. Throughout PICU stay, leak conductance is associated with fractional volume loss. This study demonstrates that leak conductance, calculated from routinely available pressure and flow signals, has the potential to represent the characteristics of the leak interface between a TT and the trachea.

G2 acquisition by transcription-independent mechanism at the zebrafish midblastula transition.

Following fertilization of many animal embryos, rapid synchronous cleavage divisions give way to longer, asynchronous cell cycles at the midblastula transition (MBT). The cell cycle changes at the MBT, including the addition of gap phases and checkpoint controls, are accompanied by activation of the zygotic genome and the onset of cell motility. Whereas the biochemical changes accompanying the MBT in the vertebrate embryo have been extensively documented, the cellular events are not well understood. We show that cell cycle remodeling during the zebrafish MBT includes the transcription-independent acquisition of a G2 phase that is essential for preventing entry into mitosis before S-phase completion in cycles 11-13. We provide evidence from high-resolution imaging that inhibition of Cdc25a and Cdk1 activity, but not Cdk2 activity, is essential for cell cycle lengthening and asynchrony between cycles 9 and 12. We demonstrate that lengthening is not required for initiation of zygotic transcription. Our results are consistent with findings from Drosophila and Xenopus that indicate the central importance of G2 addition in checkpoint establishment, and point to similar mechanisms governing the MBT in diverse species.

Ross operation: 16-year experience.

OBJECTIVE: We performed a review of a consecutive series of 487 patients undergoing the Ross operation to identify surgical techniques and clinical parameters that affect outcome. METHODS: We performed a prospective review of consecutive patients from August 1986 through June 2002 and follow-up through August 2004. Patient age was 2 days to 62 years (median, 24 years), and 197 patients were less than 18 years of age. The Ross operation was performed as a scalloped subcoronary implant in 26 patients, an inclusion cylinder in 54 patients, root replacement in 392 patients, and root-Konno procedure in 15 patients. Clinical follow-up in 96% and echocardiographic evaluation in 77% were performed within 2 years of closure. RESULTS: Actuarial survival was 82% +/- 6% at 16 years, and hospital mortality was 3.9%. Freedom from autograft failure (autograft reoperation and valve-related death) was 74% +/- 5%. Male sex and primary diagnosis of aortic insufficiency (no prior aortic stenosis) were significantly associated with autograft failure by means of multivariate analysis. Freedom from autograft valve replacement was 80% +/- 5%. Freedom from endocarditis was 95% +/- 2%. One late thromboembolic episode occurred. Freedom from allograft reoperation or reintervention was 82% +/- 4%. Freedom from all valve-related events was 63% +/- 6%. In children survival was 84% +/- 8%, and freedom from autograft valve failure was 83% +/- 6%. CONCLUSIONS: The Ross operation provides excellent survival in adults and children willing to accept a risk of reoperation. Male sex and a primary diagnosis of aortic insufficiency had a negative effect on late results.