Waveguide-integrated silicon T centres

The performance of modular, networked quantum technologies will be strongly dependent upon the quality of their quantum light-matter interconnects. Solid-state colour centres, and in particular T centres in silicon, offer competitive technological and commercial advantages as the basis for quantum networking technologies and distributed quantum computing. These newly rediscovered silicon defects offer direct telecommunications-band photonic emission, long-lived electron and nuclear spin qubits, and proven native integration into industry-standard, CMOS-compatible, silicon-on-insulator (SOI) photonic chips at scale. Here we demonstrate further levels of integration by characterizing T centre spin ensembles in single-mode waveguides in SOI. In addition to measuring long spin T₁ times, we report on the integrated centres' optical properties. We find that the narrow homogeneous linewidth of these waveguide-integrated emitters is already sufficiently low to predict the future success of remote spin-entangling protocols with only modest cavity Purcell enhancements. We show that further improvements may still be possible by measuring nearly lifetime-limited homogeneous linewidths in isotopically pure bulk crystals. In each case the measured linewidths are more than an order of magnitude lower than previously reported and further support the view that high-performance, large-scale distributed quantum technologies based upon T centres in silicon may be attainable in the near term.

Impact of a screen, triage and treat program for identifying chronic disease risk in Indigenous children

BACKGROUND

The First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis project was a point-of-care screening program in rural and remote First Nations communities in Manitoba that aimed to identify and treat hypertension, diabetes and chronic kidney disease. The program identified chronic disease in 20% of children screened. We aimed to characterize clinical screening practices before and after intervention in children aged 10-17 years old and compare outcomes with those who did not receive the intervention.

METHODS

This observational, prospective cohort study started with community engagement and followed the principles of ownership, control, access and possession (OCAP). We linked participant data to administrative data at the Manitoba Centre for Health Policy to assess rates of primary care and nephrology visits, disease-modifying medication prescriptions and laboratory testing (i.e., glycosylated hemoglobin [HbA_1c], estimated glomerural filtration rate [eGFR] and urine albumin- or protein-to-creatinine ratio). We analyzed the differences in proportions in the 18 months before and after the intervention. We also conducted a 1:2 propensity score matching analysis to compare outcomes of children who were screened with those who were not.

RESULTS

We included 324 of 353 children from the screening program (43.8% male; median age 12.3 yr) in this study. After the intervention, laboratory testing increased by 5.8% (95% confidence interval [CI] 1.1% to 10.1%) for HbA_1c, by 9.9% (95% CI 4.2% to 15.5%) for eGFR and by 6.2% (95% CI 2.3% to 10.0%) for the urine albumin- or protein-to-creatinine ratio. We observed significant improvements in laboratory testing in screened patients in the group who were part of the program, compared with matched controls.

INTERPRETATION

Chronic disease surveillance and care increased significantly in children after the implementation of a point-of-care screening program in rural and remote First Nation communities. Interventions such as active surveillance programs have the potential to improve the chronic disease care being provided to First Nations children.

Impact of point-of-care screening for hypertension, diabetes and progression of chronic kidney disease in rural Manitoba Indigenous communities

BACKGROUND:

In 2013–2015, we conducted point-of-care screening for hypertension, diabetes and chronic kidney disease in rural and remote Indigenous communities in Manitoba, Canada. In this study, we aimed to determine whether optimal follow-up care was provided, defined as proportion of individuals with appropriate kidney disease laboratory testing, medication prescriptions and physician visits.

METHODS:

We linked screening data from participants to provincial administrative data sets to evaluate whether frequencies of laboratory testing, prescriptions of disease-modifying medications, and primary care and nephrology visits differed in the 18 months before and after screening. We also conducted a propensity score matching analysis to compare outcomes between screened and unscreened adults.

RESULTS:

Of 1353 adults who received the screening intervention and who had complete administrative data available, 44% were at risk of kidney failure at screening. Among these individuals, frequencies of comprehensive laboratory testing (estimated glomerular filtration rate and urine albumin to creatinine ratio) improved by 17.0% (95% confidence interval [CI] 11.5 to 22.5), anti-hyperglycemic medications improved by 4.4% (95% CI 1.0 to 7.8), and nephrology visits for participants meeting referral criteria improved by 5.9% (95% CI 3.4 to 8.5). We observed significant improvements in laboratory testing, antihyperglycemic medications and nephrology visits in the screened group compared with the 1:1 matched comparison group.

INTERPRETATION:

Point-of-care screening programs in rural and remote Indigenous communities are adaptable methods for increasing awareness, monitoring risk and treating chronic diseases. Interventions such as the development of a national screening program could improve chronic disease care in high-risk populations.

Kidney Check Point-of-Care Testing-Furthering Patient Engagement and Patient-Centered Care in Canada's Rural and Remote Indigenous Communities: Program Report

Purpose of program

Access to health care services remains a significant barrier for many Indigenous people's living in rural and remote regions of Canada. Driven by geographical isolation and compounded by socioeconomic and environmental disparities, individuals living under these circumstances face disproportionately poor health outcomes. Kidney Check is a comprehensive screening, triage, and treatment initiative working to bring culturally safe preventive care to rural and remote Indigenous communities across Manitoba, Ontario, BC, Alberta, and Saskatchewan. The project's patient-oriented approach addresses concerns raised by kidney patients and their caregivers using culturally safe practices. Using the various expertise of their multidisciplinary team, Kidney Check seeks to further collaborative efforts to improve access to preventive health care for these groups. Meaningful engagement with patients, communities, and local health care stakeholders ensures Indigenous voices are heard and incorporated into the project in a way that promotes shared decision-making and sustainability.

Sources of information

As an affiliate program of the Can-SOLVE CKD Network, Kidney Check's guiding priorities were developed over 3 years of patient consultation and finalized during 2 workshops held with more than 30 patients, caregivers, Indigenous peoples, researchers, and policy makers using a modified Delphi process. Today, patients continue to participate in project development via 2 governing bodies: The Patient Governance Circle and the Indigenous Peoples Engagement and Research Council (IPERC).

Methods

Modeled after the Indigenous-led 2015 FINISHED project in Manitoba, Kidney Check employs point-of-care testing to identify diabetes, hypertension, and chronic kidney disease (CKD) in individuals, ages 10 and above, regardless of pre-existing risk factors. The Kidney Check team consists of 4 working groups: project leadership, provincial management, local community partners, and patient partners. By using and building on existing relationships between local and provincial health care stakeholders and various Indigenous communities, the program furthers collaborative efforts to bridge gaps in health equity.

Key findings

The Kidney Check program has established an infrastructure that integrates patient engagement at all stages of the program from priority setting to deployment and dissemination strategies.

Limitations

While we encourage and offer screening services to all, many still choose not to attend for a variety of reasons which may introduce selection bias. Kidney Check uses patient engagement as a foundational component of the program; however, there is currently a limited amount of research documenting the benefits of patient engagement in health care settings. More formal qualitative evaluations of these activities are needed. In addition, as the COVID-19 pandemic has halted screening procedures in most communities, we currently do not have quantitative data to support the efficacy of the Kidney Check program.

Implications

For many Indigenous people, lack of accessibility to health care services is compounded by sociopolitical barriers that disrupt relationships between patients and providers. Meaningful engagement presents one opportunity to ensure the voices and perspectives of Indigenous patients and communities are incorporated into health services. In addition, this screening paradigm has shown to be cost effective as shown by analyses done on the FINISHED screening program.

Is Assisted Peritoneal Dialysis a Solution for Northern Manitoba?

Background:

End-stage kidney disease (ESKD) continues to fundamentally impact the lives of First Nations (FN) patients. Home peritoneal dialysis (PD) offers patients more mobility and flexibility, but few Manitoba FNs have availed themselves of this option.

Objective:

This paper discusses Manitoba FNs' experience of PD, to highlight enablers and barriers to expanding the use of PD in rural and remote Manitoba communities.

Methods:

We analyzed interviews of individuals living with ESKD (N = 14), family caregivers (N = 14) and healthcare providers and administrators (N = 27).

Results:

Barriers to PD uptake include medical suitability, patients' distrust of home modalities and fear in their ability to manage. Other factors include limited family support and lack of appropriate housing.

Conclusions:

Assisted peritoneal dialysis (APD) is an emerging model where PD supplies are centrally located, and where a cohort of PD patients can provide mutual support with added assistance from an APD worker. This model could mitigate existing treatment barriers.

Evaluation of the Abbott ARCHITECT™ cytomegalovirus IgM/IgG, rubella IgM/IgG, and syphilis treponemal antibodies enzyme immunoassays in a mother and child health center population

This study evaluated the concordance of Architect™ chemiluminescent microparticle immunoassays with Captia™ ELISA for cytomegalovirus (CMV) IgM and IgG, with Enzygnost™ and Captia™ ELISA for rubella IgM and IgG and with Trep-Sure™ ELISA for syphilis treponemal antibodies in a mixed pediatric and obstetrical population. Total agreement between assays and Kappa statistic value were 82.5% (95% CI: 75.6-87.7) and 0.65 (95% CI: 0.54-0.77) for CMV IgM, 82.8% (95% CI: 76.7-87.6) and 0.65 (95% CI: 0.55-0.75) for CMV IgG, 89.2% (95% CI: 82.9-93.4) and 0.56 (95% CI: 0.36-0.75) for rubella IgM, 88.6% (95% CI: 82.9-92.6) and 0.74 (95% CI: 0.63-0.84) for rubella IgG, and 97.9% (95% CI: 94.5-99.4) and 0.89 (95% CI: 0.79-1.00) for syphilis treponemal antibodies. This study demonstrates that the Architect™ chemiluminescent microparticle immunoassays correlate well with other FDA-approved ELISA assays in this specific population.

Very Preterm Infants with Technological Dependence at Home: Impact on Resource Use and Family

OBJECTIVE

To examine the impact of medical complexity among very preterm infants on health care resource use, family, and neurodevelopmental outcomes at 18 months' corrected age.

METHODS

This observational cohort study of Canadian infants born < 29 weeks' gestational age in 2009-2011 compared infants with and those without medical complexity defined as discharged home with assistive medical technology. Health care resource use and family outcomes were collected. Children were assessed for cerebral palsy, deafness, blindness, and developmental delay at 18 months. Logistic regression analysis was performed for group comparisons.

RESULTS

Overall, 466/2,337 infants (20%) needed assistive medical technology at home including oxygen (79%), gavage feeding (21%), gastrostomy or ileostomy (20%), CPAP (5%), and tracheostomy (3%). Children with medical complexity were more likely to be re-hospitalized (OR 3.6, 95% CI 3.0-4.5) and to require ≥2 outpatient services (OR 4.4, 95% CI 3.5-5.6). Employment of both parents at 18 months was also less frequent in those with medical complexity compared to those without medical complexity (52 vs. 60%, p < 0.01). Thirty percent of children with medical complexity had significant neurodevelopmental impairment compared to 13% of those without medical complexity (p < 0.01). Lower gestational age, lower birth weight, bronchopulmonary dysplasia, sepsis, and surgical necrotizing enterocolitis were associated with a risk of medical complexity.

CONCLUSION

Medical complexity is common following very preterm birth and has a significant impact on health care use as well as family employment and is more often associated with neurodevelopmental disabilities. Efforts should be deployed to facilitate care coordination upon hospital discharge and to support families of preterm children with medical complexity.

THE EPIDEMIOLOGY AND CLINICAL FEATURES OF SEPTIC ARTHRITIS CASES SECONDARY TO KINGELLA KINGAE IN COMPARISON TO SEPTIC ARTHRITIS FROM OTHER PATHOGENS

BACKGROUND

In Europe, Kingella kingae (Kk) is considered as a significant pathogen in osteoarticular infections (OAI) in young children. Some authors suggest that a significant portion of ‘culture negative septic arthritis’ may be secondary to the inability to isolate K. kingae using conventional methods. However, its pathogenic role and prevalence remain controversial in North America. Since 2014, in order to optimize the microbiological diagnosis of OAI, all osteo-articular specimens submitted to our laboratory for bacteriology culture were simultaneously tested with a home brew multiplex PCR assay detecting Kk, Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus pneumoniae. Consequently, an important increase in Kk OAI proven cases was observed. The clinical presentation of Kk OAI comparatively to the other most common pathogens seen in paediatric OAI has yet to be described in North America.

OBJECTIVES

The aim of this study is to review all cases of acute septic arthritis (SA) in our institution to define the prevalence of Kk SA and to compare the clinical presentation of SA cases according to their bacterial etiology, with a deeper look at SA caused by Kk.

DESIGN/METHODS

We conducted a retrospective chart review of all cases of suspected SA who had a synovial fluid sample submitted for bacteriology culture and multiplex PCR analysis to our microbiology laboratory between May 2014 and May 2017. Only cases of acute SA (< 1 month symptom duration prior to diagnosis) were included. Children with final diagnosis that were not of infectious origin (e.g. rheumatoid arthritis, transient synovitis, etc) were excluded. Probable SA cases were defined as cases with a clinical presentation concordant with SA without any causative bacteria identified, that have received antibiotic treatment for >2 weeks. Eligible SA cases were then stratified into 4 groups according to the final microbiology diagnosis: Kk SA, S. aureus SA, “other bacteria” SA or probable SA. One-way ANOVA with Tukey’s multiple comparison test if appropriate was subsequently performed to compare demographics, clinical and biochemical data, duration of treatment and outcome between subgroups.

RESULTS

Of the 153 patients who submitted a synovial fluid sample, 71 met the inclusion criteria. A microorganism was found in 56 patients (79%): Kk was found in 37 cases (52%), S. aureus in 11 cases (15%), S. pyogenes in 7 patients (10%), and Salmonella in 1 patient (1%); and there were15 probable SA cases (21%). Interestingly, Kk cases were proven by PCR only in 86% (n=32/37) of cases (culture was negative).

One-way ANOVA showed a significant difference in age between subgroups [F(3, 67) = 13,60, p<0,0001]:patients infected by Kk were younger (M=1,50 years old, SD=0,68) than S. aureus (M=7.48, SD=4.84), “other bacteria” (M=5,86, SD=4,37) and probable SA subgroups (M=5,80, SD=4,90).

The duration of fever (days) was shorter [F(3, 67) = 14,07, p=0,028] in patients with Kk (M=4,1, SD=3,3) and probable SA (M=2,9 SD=3,6) in comparison to “other bacteria” cases (M=8,8, SD=8,3).

Also, maximal CRP values [F(3, 67) = 14,80, p<0,0001] were lower in Kk (M=42,7, SD=38,1) and probable SA (M=36,4, SD=34,6) than in SA caused by other bacteria (M=178,5, SD=98,8). Similarly, maximal neutrophil count [F(3, 67) = 6.71, p=0,0005] was lower in Kk cases (M=5,6 SD=2,3) in comparison to those infected by other bacteria (M=11,6, SD=4,1).

CONCLUSION

In our institution, since the implementation of multiplex PCR testing for OA samples, Kk has become the most prevalent pathogen causing SA. Children with Kk SA appear to be younger and to have a less inflammatory clinical presentation, as shown by a shorter duration of fever, lower CRP and lower neutrophil values in comparison to cases attributable to other bacteria. Prevalence of Kk SA is probably underestimated in settings where only bacteriology culture is performed.

Screening for kidney disease in Indigenous Canadian children: The FINISHED screen, triage and treat program

Background

Indigenous populations are disproportionately affected by kidney failure at younger ages than other ethnic groups in Canada. As symptoms do not occur until disease is advanced, early kidney disease risk is often unrecognized.

Objectives

We sought to evaluate the yield of community-based screening for early risk factors for kidney disease in youth from rural Indigenous communities in Canada.

Methods

The FINISHED project screened 11 rural First Nations communities in Manitoba, Canada after community and school engagement. The results for the 10- to 17-year olds are reported here. Body mass index (BMI), blood pressure, estimated glomerular filtration rate (eGFR), hemoglobin A1c's (HbA1c) and urine albumin-to-creatinine ratios (ACR) were assessed. All children were triaged and referred to either primary or tertiary care, depending on risk.

Results

A total of 353 were screened (estimated 22.4% of population). The median age was 12 years (IQR 10 to 13), 55% were female and 55% were overweight or obese. Overall, 21.8% of children had at least one abnormality. Hypertension was identified in 5.4% and 11.9% had prehypertension. None of the children had an eGFR < 60 ml/min/1.73 m² however 10.5% had an ACR > 3 mg/mmol and 6.2% had an eGFR < 90 ml/min/1.73 m² suggestive of early kidney disease. Diabetes was identified in 1.4%, and 1.4% had HbA1c's between 6.1% and 6.49%.

Conclusions

Risk factors for chronic kidney disease are highly prevalent in rural Indigenous children. More research is required to confirm the persistence of these findings, and to evaluate the efficacy of screening children to prevent or delay progression to kidney failure.

Using a standardised protocol was effective in reducing hospitalisation and treatment use in children with newly diagnosed immune thrombocytopenia

AIM

Childhood immune thrombocytopenia (ITP) has been associated with low bleeding rates and a high frequency of spontaneous remission. Although current guidelines suggest that most patients are just observed, children still receive platelet-enhancing therapies for fear of bleeding complications. We hypothesised that a standardised protocol with a step-down approach would reduce hospitalisation and treatment use.

METHOD

A retrospective chart review was performed on patients diagnosed with acute ITP between January 2010 and December 2014, before (n = 54) and after (n = 37) the standardised protocol, which was introduced in January 2013. Management and events during the first 3 months following diagnosis were recorded.

RESULTS

The protocol resulted in a 34% decrease in the hospitalisation rate (p < 0.001) at diagnosis. Prednisone treatment duration at diagnosis was also significantly reduced (13.1 versus 5.8 days, p = 0.004). Children over 3 years of age were 3.8 times less likely to be hospitalised (95% CI 1.94-7.61) and 2.3 times less likely to receive treatment (95% CI 1.2-4.3). There was no difference in the rate of persistent ITP (38% versus 30%, p = 0.43) or serious bleeding complications (7% versus 5%, p = 0.70).

CONCLUSION

Our ITP management protocol significantly reduced hospitalisation rates and length of prednisone treatment without any increase in disease complications.

Diagnostic Accuracy of Novel and Traditional Rapid Tests for Influenza Infection Compared With Reverse Transcriptase Polymerase Chain Reaction: A Systematic Review and Meta-analysis

BACKGROUND

Rapid and accurate influenza diagnostics can improve patient care.

PURPOSE

To summarize and compare accuracy of traditional rapid influenza diagnostic tests (RIDTs), digital immunoassays (DIAs), and rapid nucleic acid amplification tests (NAATs) in children and adults with suspected influenza.

DATA SOURCES

6 databases from their inception through May 2017.

STUDY SELECTION

Studies in English, French, or Spanish comparing commercialized rapid tests (that is, providing results in <30 minutes) with reverse transcriptase polymerase chain reaction reference standard for influenza diagnosis.

DATA EXTRACTION

Data were extracted using a standardized form; quality was assessed using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) criteria.

DATA SYNTHESIS

162 studies were included (130 of RIDTs, 19 of DIAs, and 13 of NAATs). Pooled sensitivities for detecting influenza A from Bayesian bivariate random-effects models were 54.4% (95% credible interval [CrI], 48.9% to 59.8%) for RIDTs, 80.0% (CrI, 73.4% to 85.6%) for DIAs, and 91.6% (CrI, 84.9% to 95.9%) for NAATs. Those for detecting influenza B were 53.2% (CrI, 41.7% to 64.4%) for RIDTs, 76.8% (CrI, 65.4% to 85.4%) for DIAs, and 95.4% (CrI, 87.3% to 98.7%) for NAATs. Pooled specificities were uniformly high (>98%). Forty-six influenza A and 24 influenza B studies presented pediatric-specific data; 35 influenza A and 16 influenza B studies presented adult-specific data. Pooled sensitivities were higher in children by 12.1 to 31.8 percentage points, except for influenza A by rapid NAATs (2.7 percentage points). Pooled sensitivities favored industry-sponsored studies by 6.2 to 34.0 percentage points. Incomplete reporting frequently led to unclear risk of bias.

LIMITATIONS

Underreporting of clinical variables limited exploration of heterogeneity. Few NAAT studies reported adult-specific data, and none evaluated point-of-care testing. Many studies had unclear risk of bias.

CONCLUSION

Novel DIAs and rapid NAATs had markedly higher sensitivities for influenza A and B in both children and adults than did traditional RIDTs, with equally high specificities.

PRIMARY FUNDING SOURCE

Québec Health Research Fund and BD Diagnostic Systems.

Time to Positivity of Blood Cultures in Infants 0 to 90 Days Old Presenting to the Emergency Department: Is 36 Hours Enough?

BACKGROUND

Continuous monitoring blood culture systems (CMBCS) now allow for more rapid detection of microbial growth. We aimed to determine whether a 36-hour period was sufficient to detect all blood cultures positive for pathogenic bacteria in infants 0 to 90 days old undergoing a septic workup in the emergency department of a tertiary care pediatric center.

METHODS

We performed a retrospective study of all positive blood cultures collected in these infants over a 5-year time period (from March 13, 2008 to July 29, 2013). Bottles were incubated in a CMBCS. The time to positivity (TTP) was calculated from time of blood culture registration into the laboratory system to time of Gram stain. Medical charts were reviewed for relevant clinical information. Cultures were classified as pathogenic or contaminant using microorganism type and clinical presentation.

RESULTS

Three thousand five hundred fifty-nine blood cultures were collected. Of these, 98 (2.8%) were positive. Fifty-two (53.1%) were deemed pathogenic and 46 (46.9%) were deemed contaminant, for a true prevalence of bacteremia of 1.5%. At 24, 36, 48, and 50 hours, 87.8% (86 of 98), 96.9% (95 of 98), 99% (97 of 98), and 100% (98 of 98) of all cultures were positive. Considering only pathogenic organisms, 96.1% (50 of 52) and 100% (52 of 52) were positive at 24 and 36 hours. Mean TTP for pathogens and contaminants was 14.40 and 23.18 hours, respectively (P < .001).

CONCLUSIONS

An incubation period of 36 hours is sufficient to detect 100% of blood cultures positive for a pathogenic organism in our population.

The Prevalence of CKD in Rural Canadian Indigenous Peoples: Results From the First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis (FINISHED) Screen, Triage, and Treat Program

BACKGROUND

Indigenous Canadians have high rates of risk factors for chronic kidney disease (CKD), in particular diabetes. Furthermore, they have increased rates of complications associated with CKD, such as kidney failure and vascular disease. Our objective was to describe the prevalence of CKD in this population.

STUDY DESIGN

Cross-sectional cohort.

SETTING & PARTICIPANTS

Indigenous (First Nations) Canadians 18 years or older screened as part of the First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis (FINISHED) project, an initiative completed in 2015 that accomplished community-wide screening in 11 rural communities in Manitoba, Canada.

PREDICTORS

Indigenous ethnicity and geographic location (communities accessible by road compared with those accessible only by air).

OUTCOME

Prevalence of CKD, presumed based on a single ascertainment of urine albumin-creatinine ratio (UACR) ≥ 30mg/g and/or estimated glomerular filtration rate (eGFR)<60mL/min/1.73m(2).

MEASUREMENTS

Kidney function measured by eGFR (CKD-EPI creatinine equation) and UACR.

RESULTS

1,346 adults were screened; 25.5% had CKD, defined as UACR≥30mg/g or eGFR<60mL/min/1.73m(2). Communities accessible by road had a lower prevalence of CKD (17.6%) than more remote communities accessible only by air (34.4%). Of those screened, 3.3% had reduced kidney function (defined as eGFR<60mL/min/1.73m(2)). Severely increased albuminuria was present in 5.0% of those screened.

LIMITATIONS

Presumption of chronicity based on a single ascertainment. There is a possibility of sampling bias, the net direction of which is uncertain.

CONCLUSIONS

We found a 2-fold higher prevalence of CKD in indigenous Canadians in comparison to the general population and a prevalence of severely increased albuminuria that was 5-fold higher. This is comparable to patients with diabetes and/or hypertension. Public health strategies to screen, triage, and treat all Canadian indigenous peoples with CKD should be considered.

Evaluation of the abbot Architect(™) epstein-barr virus viral capsid antigen IgM, viral capsid antigen IgG and nuclear antigen IgG assays in a pediatric and adult population

BACKGROUND

The detection of antibodies against Epstein-Barr viral capsid (VCA) and nuclear (EBNA) antigens is routinely performed with different commercially available immunoassays.

OBJECTIVES

In this study, we evaluated the concordance and performance of the Architect(™) chemiluminescent microparticle immunoassays (CMIAs) using Captia(™) enzyme linked immunosorbent assays (ELISA) for VCA IgM, and standard immunofluorescence (IF) assays for VCA IgG and EBNA IgG as comparative techniques.

STUDY DESIGN

Sera were selected from a heterogeneous population including pediatric and adult patients.

RESULTS

Concordance between CMIAs and comparative assays was high with total agreement percentages of 84,1% (95% CI: 77.8-88.9) for VCA IgM, 90,6% (95% CI: 84.2-94.7) for EBNA IgG and 98,0% (95% CI: 93.9-99.6) for VCA IgG. Moreover, kappa statistic values showed good to excellent correlation with values of 0.68 (95% CI: 0.57-0.79) for VCA IgM, 0.73 (95% CI: 0.58-0.87) for EBNA IgG and 0.95 (95% CI: 0.89-1.00) for VCA IgG. A correlation was observed between positivity levels on CMIAs and semi-quantitative fluorescence intensity on IF for VCA IgG and EBNA IgG assays. With regard to an accepted gold standard IF assays, CMIA was 98,1% (95% CI: 93.3-99.8) sensitive and 97,4% (95% CI: 86.5-99.9) specific for the detection of VCA IgG. For the detection of EBNA IgG, it was 92,2% (95% CI: 85.1-96.6) sensitive and 84,6% (95% CI: 65.1-95.6) specific.

CONCLUSION

In summary, we demonstrated that the CMIA EBV antibody detection panel has high performance and high concordance with other commercially available immunoassays.

Addition of long-acting beta2-agonists to inhaled corticosteroids for chronic asthma in children

BACKGROUND

Long-acting beta2-agonists (LABA) in combination with inhaled corticosteroids (ICS) are increasingly prescribed for children with asthma.

OBJECTIVES

To assess the safety and efficacy of adding a LABA to an ICS in children and adolescents with asthma. To determine whether the benefit of LABA was influenced by baseline severity of airway obstruction, the dose of ICS to which it was added or with which it was compared, the type of LABA used, the number of devices used to deliver combination therapy and trial duration.

SEARCH METHODS

We searched the Cochrane Airways Group Asthma Trials Register until January 2015.

SELECTION CRITERIA

We included randomised controlled trials testing the combination of LABA and ICS versus the same, or an increased, dose of ICS for at least four weeks in children and adolescents with asthma. The main outcome was the rate of exacerbations requiring rescue oral steroids. Secondary outcomes included markers of exacerbation, pulmonary function, symptoms, quality of life, adverse events and withdrawals.

DATA COLLECTION AND ANALYSIS

Two review authors assessed studies independently for methodological quality and extracted data. We obtained confirmation from trialists when possible.

MAIN RESULTS

We included in this review a total of 33 trials representing 39 control-intervention comparisons and randomly assigning 6381 children. Most participants were inadequately controlled on their current ICS dose. We assessed the addition of LABA to ICS (1) versus the same dose of ICS, and (2) versus an increased dose of ICS.LABA added to ICS was compared with the same dose of ICS in 28 studies. Mean age of participants was 11 years, and males accounted for 59% of the study population. Mean forced expiratory volume in one second (FEV1) at baseline was ≥ 80% of predicted in 18 studies, 61% to 79% of predicted in six studies and unreported in the remaining studies. Participants were inadequately controlled before randomisation in all but four studies.There was no significant group difference in exacerbations requiring oral steroids (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.70 to 1.28, 12 studies, 1669 children; moderate-quality evidence) with addition of LABA to ICS compared with ICS alone. There was no statistically significant group difference in hospital admissions (RR 1.74, 95% CI 0.90 to 3.36, seven studies, 1292 children; moderate-quality evidence)nor in serious adverse events (RR 1.17, 95% CI 0.75 to 1.85, 17 studies, N = 4021; moderate-quality evidence). Withdrawals occurred significantly less frequently with the addition of LABA (23 studies, 471 children, RR 0.80, 95% CI 0.67 to 0.94; low-quality evidence). Compared with ICS alone, addition of LABA led to significantly greater improvement in FEV1 (nine studies, 1942 children, inverse variance (IV) 0.08 L, 95% CI 0.06 to 0.10; mean difference (MD) 2.99%, 95% CI 0.86 to 5.11, seven studies, 534 children; low-quality evidence), morning peak expiratory flow (PEF) (16 studies, 3934 children, IV 10.20 L/min, 95% CI 8.14 to 12.26), reduction in use of daytime rescue inhalations (MD -0.07 puffs/d, 95% CI -0.11 to -0.02, seven studies; 1798 children) and reduction in use of nighttime rescue inhalations (MD -0.08 puffs/d, 95% CI -0.13 to -0.03, three studies, 672 children). No significant group difference was noted in exercise-induced % fall in FEV1, symptom-free days, asthma symptom score, quality of life, use of reliever medication and adverse events.A total of 11 studies assessed the addition of LABA to ICS therapy versus an increased dose of ICS with random assignment of 1628 children. Mean age of participants was 10 years, and 64% were male. Baseline mean FEV1 was ≥ 80% of predicted. All trials enrolled participants who were inadequately controlled on a baseline inhaled steroid dose equivalent to 400 µg/d of beclomethasone equivalent or less.There was no significant group differences in risk of exacerbation requiring oral steroids with the combination of LABA and ICS versus a double dose of ICS (RR 1.69, 95% CI 0.85 to 3.32, three studies, 581 children; moderate-quality evidence) nor in risk of hospital admission (RR 1.90, 95% CI 0.65 to 5.54, four studies, 1008 children; moderate-quality evidence).No statistical significant group difference was noted in serious adverse events (RR 1.54, 95% CI 0.81 to 2.94, seven studies, N = 1343; moderate-quality evidence) and no statistically significant differences in overall risk of all-cause withdrawals (RR 0.96, 95% CI 0.67 to 1.37, eight studies, 1491 children; moderate-quality evidence). Compared with double the dose of ICS, use of LABA was associated with significantly greater improvement in morning PEF (MD 8.73 L/min, 95% CI 5.15 to 12.31, five studies, 1283 children; moderate-quality evidence), but data were insufficient to aggregate on other markers of asthma symptoms, rescue medication use and nighttime awakening. There was no group difference in risk of overall adverse effects, A significant group difference was observed in linear growth over 12 months, clearly indicating lower growth velocity in the higher ICS dose group (two studies: MD 1.21 cm/y, 95% CI 0.72 to 1.70).

AUTHORS' CONCLUSIONS

In children with persistent asthma, the addition of LABA to ICS was not associated with a significant reduction in the rate of exacerbations requiring systemic steroids, but it was superior for improving lung function compared with the same or higher doses of ICS. No differences in adverse effects were apparent, with the exception of greater growth with the use of ICS and LABA compared with a higher ICS dose. The trend towards increased risk of hospital admission with LABA, irrespective of the dose of ICS, is a matter of concern and requires further monitoring.

Evaluation of a fluorescent immunoassay rapid test (Sofia™) for detection of influenza A+B and RSV in a tertiary pediatric setting

In response to the lack of sensitivity and reproducibility of previously marketed rapid antigen detection tests, a novel fluorescent immunoassay was recently developed. This new assay offers rapidity and automated reading. More characterization of this assay is needed. The aim of this study was to assess diagnostic performance of Sofia influenza A+B and respiratory syncytial virus (RSV) while compared to traditional viral cell culture. A total of 416 respiratory samples were analyzed prospectively with both methods in a tertiary pediatric center. Sensitivity and specificity of the Sofia™ test were 90.0% and 98.0% for influenza A, 90.9% and 98.9% for influenza B, and 87.7% and 94.7% for RSV compared to traditional cell culture. Overall, Sofia influenza A+B and RSV assays performed well in comparison to culture in a pediatric population.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. However, often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov web site up to October 2012.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1. Quality of the evidence was assessed using GRADE.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32; the large confidence interval translates into a risk of exacerbations in the intermittent ICS group varying between 17% and 25%, assuming a 19% risk with daily ICS). Age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β2-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV1), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, there was low quality evidence that intermittent and daily ICS strategies were similarly effective in the use of rescue oral corticosteroids and the rate of severe adverse health events. The strength of the evidence means that we cannot currently assume equivalence between the two options.. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. Clinicians should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. Yet often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov website up to December 2011.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32). The patients' age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β(2)-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV(1)), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, intermittent and daily ICS strategies did not significantly differ in the use of rescue oral corticosteroids and the rate of severe adverse health events, neither did they reach equivalence. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. The clinician should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Accuracy of rapid influenza diagnostic tests: a meta-analysis

BACKGROUND

Timely diagnosis of influenza can help clinical management.

PURPOSE

To examine the accuracy of rapid influenza diagnostic tests (RIDTs) in adults and children with influenza-like illness and evaluate factors associated with higher accuracy.

DATA SOURCES

PubMed and EMBASE through December 2011; BIOSIS and Web of Science through March 2010; and citations of articles, guidelines, reviews, and manufacturers.

STUDY SELECTION

Studies that compared RIDTs with a reference standard of either reverse transcriptase polymerase chain reaction (first choice) or viral culture.

DATA EXTRACTION

Reviewers abstracted study data by using a standardized form and assessed quality by using Quality Assessment of Diagnostic Accuracy Studies criteria.

DATA SYNTHESIS

159 studies evaluated 26 RIDTs, and 35% were conducted during the H1N1 pandemic. Failure to report whether results were assessed in a blinded manner and the basis for patient recruitment were important quality concerns. The pooled sensitivity and specificity were 62.3% (95% CI, 57.9% to 66.6%) and 98.2% (CI, 97.5% to 98.7%), respectively. The positive and negative likelihood ratios were 34.5 (CI, 23.8 to 45.2) and 0.38 (CI, 0.34 to 0.43), respectively. Sensitivity estimates were highly heterogeneous, which was partially explained by lower sensitivity in adults (53.9% [CI, 47.9% to 59.8%]) than in children (66.6% [CI, 61.6% to 71.7%]) and a higher sensitivity for influenza A (64.6% [CI, 59.0% to 70.1%) than for influenza B (52.2% [CI, 45.0% to 59.3%).

LIMITATION

Incomplete reporting limited the ability to assess the effect of important factors, such as specimen type and duration of influenza symptoms, on diagnostic accuracy.

CONCLUSION

Influenza can be ruled in but not ruled out through the use of RIDTs. Sensitivity varies across populations, but it is higher in children than in adults and for influenza A than for influenza B.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research.

The burden of cancer risk in Canada's indigenous population: a comparative study of known risks in a Canadian region

BACKGROUND

Canadian First Nations, the largest of the Aboriginal groups in Canada, have had lower cancer incidence and mortality rates than non-Aboriginal populations in the past. This pattern is changing with increased life expectancy, a growing population, and a poor social environment that influences risk behaviors, metabolic conditions, and disparities in screening uptake. These factors alone do not fully explain differences in cancer risk between populations, as genetic susceptibility and environmental factors also have significant influence. However, genetics and environment are difficult to modify. This study compared modifiable behavioral risk factors and metabolic-associated conditions for men and women, and cancer screening practices of women, between First Nations living on-reserve and a non-First Nations Manitoba rural population (Canada).

METHODS

The study used data from the Canadian Community Health Survey and the Manitoba First Nations Regional Longitudinal Health Survey to examine smoking, binge drinking, metabolic conditions, physical activity, fruit/vegetable consumption, and cancer-screening practices.

RESULTS

First Nations on-reserve had significantly higher rates of smoking (P < 0.001), binge drinking (P < 0.001), obesity (P < 0.001) and diabetes (P < 0.001), and less leisure-time physical activity (P = 0.029), and consumption of fruits and vegetables (P < 0.001). Sex differences were also apparent. In addition, First Nations women reported significantly less uptake of mammography screening (P < 0.001) but similar rates for cervical cancer screening.

CONCLUSIONS

Based on the findings of this retrospective study, the future cancer burden is expected to be high in the First Nations on-reserve population. Interventions, utilizing existing and new health and social authorities, and long-term institutional partnerships, are required to combat cancer risk disparities, while governments address economic disparities.

Immediate and short-term effects of pulmonary artery banding on left ventricular performance in foetal sheep

AIM

To evaluate foetal left ventricular performance when its preload was increased by banding the pulmonary artery, a study design where a simultaneous change in left ventricular afterload is unlikely.

METHODS

Nine ovine foetuses were studied with real-time images and Doppler echocardiography before, 3-4 and 6-8 d after surgery. Seven of these foetuses were also studied during the surgical intervention, immediately before and within 2 min after banding.

RESULTS

The immediate effects of a 90-95% reduction of the pulmonary artery cross-sectional area were: a 53 +/- 20% (mean +/- SD) decrease and a 38 +/- 10% increase of right (RvQ) and left ventricular output (LvQ), respectively. Comparing measurements before and 3-4 d after operation, there was a 64 +/- 16% decrease of RvQ and a 64 +/- 25% increase of LvQ. The increase in LvQ was due to an increase in both heart rate (19 +/- 10%) and stroke volume (38 +/- 18%). After an additional 3-4 postoperative days, heart rate remained increased to the same extent, but there was a more pronounced increase of LvQ (93 +/- 19%) and stroke volume (59 +/- 22%).

CONCLUSION

The parallel foetal circulation has a capacity to handle a severely increased afterload for the right ventricle by immediately improving and maintaining an increased left ventricular performance. This improvement was in part accomplished by an increase in stroke volume.

[Growth and pubertal development following pediatric heart transplantation]

STUDY AIM

Prospective study of growth and pubertal development following pediatric heart transplantation in 25 children.

PATIENTS AND METHOD

Twenty-five children underwent orthotopic cardiac transplantation at Ste-Justine Hospital from July 1984 to August 1996. Systematic evaluation of anthropometric parameters (weight, height, bone age), hormonal profile (LH, FSH, testosterone, oestradiol, DHEAS), and pubertal development according to Marshall and Tanner were done yearly.

RESULTS

Six patients had severe growth retardation at transplantation and only one patient was obese. All patients showed normal height increment following cardiac transplantation. Only 3 patients will not reach genetic target height. The 6 children suffering from congenital cardiomyopathy and showing severe growth delay before surgery did not show any significant catch up growth. Significant weight gain was observed during the first post-operative year (113 +/- 27% ideal body weight p = 0.0002) with evolution towards normal values at 2 years (100 +/- 18%). Thirteen patients were in the prepubertal stage at the time of transplant. Since then, one girl had her menarche at 11 years of age and 3 boys started their pubertal onset at 12 years old. The elevation of blood gonadotrophins during pubertal development correlated with progression of secondary sexual characteristics in both sexes.

CONCLUSION

This pediatric population showed normal growth and normal onset and progression of puberty following cardiac transplantation. However, no catch-up growth was observed. The most important factor influencing attainment of maximal growth potential following heart transplantation was the degree of staturoponderal growth retardation at the time of surgery.

Regulation of murine survival motor neuron (Smn) protein levels by modifying Smn exon 7 splicing

Proximal spinal muscular atrophy (SMA) is caused by mutations in the survival motor neuron gene (SMN1). In humans, two nearly identical copies of SMN exist and differ only by a single non-polymorphic C-->T nucleotide transition in exon 7. SMN1 contains a 'C' nucleotide at the +6 position of exon 7 and produces primarily full-length SMN transcripts, whereas SMN2 contains a 'T' nucleotide and produces high levels of a transcript that lacks exon 7 and a low level of full-length SMN transcripts. All SMA patients lack a functional SMN1 gene but retain at least one copy of SMN2, suggesting that the low level of full-length protein produced from SMN2 is sufficient for all cell types except motor neurons. The murine Smn gene is not duplicated or alternatively spliced. It resembles SMN1 in that the critical exon 7 +6 'C' nucleotide is conserved. We have generated Smn minigenes containing either wild-type Smn exon 7 or an altered exon 7 containing the C-->T nucleotide transition to mimic SMN2. When expressed in cultured cells or transgenic mice, the wild-type minigene produced only full-length transcripts whereas the modified minigene alternatively spliced exon 7. Furthermore, Smn exon 7 contains a critical AG-rich exonic splice enhancer sequence (ESE) analogous to the human ESE within SMN exon 7, and subtle mutations within the mESE caused a variation in Smn transcript levels. In summary, we show for the first time that the murine Smn locus can be induced to alternatively splice exon 7. These results demonstrate that SMN protein levels can be varied in the mouse by the introduction of specific mutations at the endogenous Smn locus and thereby lay the foundation for developing animals that closely 'resemble' SMA patients.

Generation of reactive O2 species in the myocardium of newborn lambs following intrauterine increase in right ventricular pressure

Fetuses with pulmonary stenosis and constriction of the ductus arteriosus or the recipient twin in the context of a twin-to-twin transfusion syndrome may present with severe right ventricular myocardial dysfunction. Free O2 radicals are known to be increased in hypertrophied adult myocardium secondary to an increase in endocavitary pressure. This study investigates whether products of reactive O2 species generation are abnormally elevated in the myocardium of fetuses with increased right ventricular pressure. Banding of the main pulmonary artery was performed in five fetal lambs at 90 to 100 days of gestation. Three other animals had a sham intervention and were used as controls. Postoperative observation lasted on average 42 days (range 33-49 days). The levels of hydroperoxides were found to be significantly higher in the right ventricle of the stenosed lambs (6.6 +/- 3.5 nmol/mg protein) compared to the left ventricle of the same lambs (0.7 +/- 0.7 nmol/mg protein), and compared to the right (0.12 +/- 0.1 nmol/mg protein) and the left (0.5 +/- 0.8 nmol/mg protein) ventricles of the controls. It is concluded that during fetal life, an increase in right ventricular pressure is associated with a marked accumulation of products of reactive O2 species generation in the right ventricular myocardium.

Growth and pubertal development following pediatric heart transplantation: a 15-year experience at Ste-Justine Hospital

BACKGROUND

Thirty-one children and adolescents have undergone allograft heart transplantation at Ste-Justine Hospital from July 1984 to August 1996. Twenty-five patients were followed prospectively more than 3 years to document their growth and pubertal development.

METHODS

Parameters surveyed were clinical (height, weight, pubertal staging, and bone age) and biochemical (luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, estradiol, dehydroepiandrosterone sulphate (DHEAS), IGF-1, and fasting insulin).

RESULTS

At surgery, there were 18 boys and 7 girls aged 11 months to 17 years (median 13 years); 14 had congenital heart defects (CHDs) and 11 had a cardiomyopathy (CM). Immunosuppressive therapy included cyclosporine, azathioprine, and prednisone. Eighteen patients were still growing (15 boys, 3 girls): 8 had a retarded bone age and 6 with CHD had severe growth failure. Following surgery, most patients maintained their height within one sodium dodecyl sulfate (SDS) score of that initially observed. Patients reaching their target heights do so mainly in the lower range. Three patients not reaching target height had a CHD. Weight was greatest 1 year postoperatively (113 +/- 27% ideal body weight) with normalization at 2 years (100 +/- 18%). Of the 13 prepubertal patients, menarche occurred at age 12 in 1 girl, while 3 boys began puberty at age 12 years. In both sexes, serum levels of gonadotropins and IGF-1 increased during puberty, moderate hyperinsulinism was observed, and DHEAS levels decreased.

CONCLUSIONS

Our results indicate that children and adolescents grow normally following cardiac transplantation and that they attain their target height despite a lack of catch-up growth. They gain weight significantly in the first postoperative year with normalization of their weight at 2 years. Furthermore, the clinical and biochemical indices of puberty are overall within the norms. However, the severity of growth delay at the time of transplantation inherent to the cardiac pathology has a major impact on adult height.

[Aortic valve stenosis in children. Surgical valvuloplasty long-term results]

From 1960 through 1992, 67 children with congenital aortic stenosis aged 6-228 months (M 105.7 +/- 52) were submitted to aortic valvuloplasty at our institution. There was no hospital mortality. During the follow-up of 127.5 +/- 66.7 months, there were two late valve related deaths. Eight patients (11.9%) developed aortic regurgitation 5 to 125 months (M 66.6 +/- 35) following surgical valvuloplasty and one of them required aortic valve replacement. Because of restenosis, 15 patients required a second operation. Of them five children underwent a second aortic valvuloplasty without mortality and, in four of them, the functional result has been excellent after a mean follow-up of 75.4 +/- 12 months. Ten patients required an aortic valve replacement 62 to 208 months post-op (M 100.9 +/- 50.8). Mechanical prosthesis were used in 6 and bioprosthesis in 4. Two patients required a Konno and one patient a Ross procedure. There were no early nor late deaths following reoperations. The 20 year survival rate following the first valvuloplasty was 94%, the freedom from reoperation 63% and the freedom from aortic valve replacement 73% for the same time period. Our results demonstrate that congenital aortic valvar stenosis in children can be surgically well controlled until adulthood. Our study also illustrates that surgical valvuloplasty is a safe and efficacious procedure and that its beneficial effect is maintained over 20 years in the majority of children.

[Ebstein's anomaly: valvular replacement in pediatric patients]

The surgical treatment of Ebstein's anomaly is still controversial. Therefore we have retrospectively studied the results of tricuspid valve replacement (TVR) performed for this anomaly at Sainte Justine Hospital. From October 1977 to December 1997, 9 patients with Ebstein's anomaly, aged from 31 to 248 months (mean 176 +/- 66), have undergone TVR. Eight children were in functional class III or IV (NYHA), while one was in class II. Seven patients underwent plication of the atrialized right ventricular segment. Eight bioprostheses (ranging in diameter from 31 to 35 mm) and one mechanical prosthesis (21 mm) were used. The valve was implanted on the tricuspid annulus in six cases. There was no operative death, nor postoperative complete heart block. Follow-up ranged from 11 to 264 months (mean 91 +/- 84). One late death occurred unrelated to surgery. The probability of 20 years survival is 88%. One patient required a second TVR 162 months after the first surgery because of bioprosthesis failure. Seven of the surviving patients are in functional class I, while one patient is in class II. This experience suggests that TVR with bioprosthesis is a good therapeutical option for children with Ebstein's anomaly since the operative risk is low, the functional status improved in all patients and the durability of bioprosthesis in tricuspid position has been good.

N-acetylcysteine in pig liver transplantation from non-heart-beating donors

Lipid peroxidation due to oxygen free radicals (OFR) seems to play a major role in loss of liver graft viability after warm ischemia, preservation, and transplantation. N-acetylcysteine (NAC) is an antioxidant that has a direct effect on OFR, and is also a glutathione precursor, another antioxidant. This study was designed to evaluate the efficacy of NAC in preventing ischemia-reperfusion damage of liver grafts harvested from non-heart-beating donors. Liver transplantation was performed on pigs divided into five groups: group 1 (control group; n=5) received livers from heart-beating donors; livers were subjected to 30 min of warm ischemia in groups 2 (n=3, no NAC) and group 3 (n=3; NAC treatment); warm ischemia time lasted 60 min in groups 4 (n=4; no NAC) and 5 (n=5; NAC treatment). Studied parameters included graft survival for more than 3 days, aspartate aminotransferase plasma levels, liver histology, and hepatic total glutathione concentrations. Graft survival was 100% in groups 1, 2, and 3, 0% in group 4, and 20% in group 5. NAC treatment did not influence initial mean aspartate aminotransferase release which was greater in warm ischemic livers than in controls. NAC treatment had no effect on liver hepatic total glutathione after reperfusion of animals receiving warm ischemic grants. Finally, no effect on liver histology was observed with NAC treatment. Our study suggests that in liver transplantation from non-heart-beating donors, NAC has no effect in both graft viability and lipid peroxidation. The role of OFR in primary dysfunction of transplanted warm ischemic livers remains controversial.

Impact of research on pediatric pain assessment and outcomes

PURPOSE

Pediatric nurses from varied practice and educational backgrounds learned about research by doing a ward-based study. The aim of the study was to determine if regular assessment of children's pain would improve their pain management and postoperative progress.

METHOD

Children, ages 5 to 17 years (n = 36), measured their pain every 4 hours postoperatively using the Wong-Baker Faces Pain Rating Scale. Outcomes regarding amount of analgesic given, subjective pain reports, time and progress of ambulation, and length of hospital stay were compared with data from a retrospective chart-review of a control group (n = 50).

FINDINGS

No statistically significant differences in these variables were found. An important clinical finding was that despite all children having prescribed PRN analgesic orders, one quarter of the children received no pain relief intervention. Also, one quarter of the children stated that their pain control was only partially effective.

CONCLUSIONS

Study results reinforce findings reported in the literature regarding ineffective pain management in children, and highlight a need for improved nursing practice. Clinical significance was achieved in terms of staff learning of the research process, increased awareness of pediatric pain management practices, improved ward morale, and inter-agency sharing of resources.

Cardioprotective effects of diltiazem during acute rejection on heterotopic heart transplants

In the presence of severe rejection, cardiac allograft perfusion has been shown to be impaired. Since a functionally reversible vasoconstrictor component has been identified in this condition and rejection does not reverse if ischemia does not, we hypothesized that diltiazem may be beneficial in this condition. Experiments were performed on dogs with heterotopic heart transplants and chronic instrumentation for the assessment of allograft perfusion. Two groups of cardiac allograft recipients were studied: untreated recipients and recipients treated with the calcium antagonist diltiazem (180 mg twice daily, orally). Allograft blood flow was monitored daily along with plasma diltiazem levels. The lymphoproliferative response to mitogens was studied at selected intervals until terminal rejection. Contractile function of the graft was assessed daily by palpation. Without immunosuppression, terminal rejection was observed within 7 days. Rejection was confirmed by histology; cellular infiltration and myocyte necrosis were present in all cardiac allografts but to a significantly lesser degree in diltiazem-treated recipients. The mean blood flow of heterotopically implanted hearts was in the range of 35-50 ml/min, which decreased steadily in untreated recipients. In contrast, significant improvement of allograft perfusion was observed in diltiazem-treated recipients at days 4-6 after transplantation. Diltiazem also significantly attenuated mitogen-induced lymphocyte proliferation at peak sensitivity (2 days after transplantation). Diltiazem plasma concentrations were in the therapeutic range (30-60 ng/ml) before and after cardiac transplantation. Results of the present study demonstrate beneficial effects of diltiazem in the course of severe cardiac rejection. Such findings support its use during rejection when maintenance of graft blood flow and myocyte protection may be important for myocardial function and viability.

Assessment of fetal pulmonic stenosis by ultrasonography

This study was designed to determine (1) the value of Doppler echocardiography in depicting the presence of a fetal pulmonary stenosis, (2) its reliability in the assessment of the severity of the lesion, and (3) the usefulness of additional markers from the left side of the heart as criteria of severity. Fourteen pregnant ewes were included in this study (gestational age, 90 to 120 days). Banding of the fetal main pulmonary artery created mild (n = 3), moderate (n = 3), and severe (n = 5) stenosis. Three lambs were sham operated. Intrauterine fetal Doppler echocardiographic data obtained 15 days after surgery were compared with preoperative values. Peak velocities recorded through the band increased linearly from baseline in the groups with mild and moderate stenosis but did not show any further increase in the group with severe stenosis. Compared with the sham-operated group, right ventricular output in the group with stenosis was either similar or reduced significantly. The increase in right ventricular free wall thickness was significantly greater in the groups with stenosis compared with that of the sham-operated group; the correlation with the degree of severity was r = 0.65 and p < 0.05. A A stronger positive correlation was found between the severity of stenosis and aortic valve diameters: r = 0.82 and p < 0.01. The strongest correlation was found for right ventricular/left ventricular outputs (r = 0.92; p < 0.001). Thus Doppler peak velocities through the obstruction can help detect pulmonic stenosis but are not reliable for the assessment of its severity during fetal life. Other ultrasound measurements such as the size of the aortic anulus and especially the ratio of right ventricular/left ventricular output could be used as sensitive markers of the severity of stenosis.

Succinyl CoA: 3-oxoacid CoA transferase (SCOT): human cDNA cloning, human chromosomal mapping to 5p13, and mutation detection in a SCOT-deficient patient

Succinyl CoA: 3-oxoacid CoA transferase (SCOT; E.C.2.8.3.5) mediates the rate-determining step of ketolysis in extrahepatic tissues, the esterification of acetoacetate to CoA for use in energy production. Hereditary SCOT deficiency in humans causes episodes of severe ketoacidosis. We obtained human-heart SCOT cDNA clones spanning the entire 1,560-nt coding sequence. Sequence alignment of the human SCOT peptides with other known CoA transferases revealed several conserved regions of potential functional importance. A single approximately 3.2-kb SCOT mRNA is present in human tissues (heart > leukocytes >> fibroblasts), but no signal is detectable in the human hepatoma cell line HepG2. We mapped the human SCOT locus (OXCT) to the cytogenetic band 5p13 by in situ hybridization. From fibroblasts of a patient with hereditary SCOT deficiency, we amplified and cloned cDNA fragments containing the entire SCOT coding sequence. We found a homozygous C-to-G transversion at nt 848, which changes the Ser 283 codon to a stop codon. This mutation (S283X) is incompatible with normal enzyme function and represents the first documentation of a pathogenic mutation in SCOT deficiency.

[Pulmonary valve replacement in children]

From February 1988 to October 1994, 15 pulmonary valve replacements (PVR) have been performed at St-Justine Hospital in children with a mean age of 145.7 months. Ten children previously had a correction of tetralogy of Fallot; two had absent pulmonary valve syndrome; one had been operated on for pulmonary atresia with intact ventricular septum, one other had a correction for a ventricular septal defect with pulmonary artery banding; the last patient developed degeneration of a pulmonary bioprosthesis. The time between the primary repair and the PVR ranged from 61 to 221 months. Fourteen bioprosthesis and one aortic homograft were implanted. All patients had antiplatelet treatment. There was one operative death due to a fatal anaphylactic reaction and one late death occurred unrelated to valvular surgery. At follow-up from 1 to 187 months (mean, 40.7 months) all patients were in New York Heart Association Class 1. No hemorrhagic nor thromboembolic complication have been observed and no reoperation for bioprosthesis failure was necessary. Nevertheless in subsequent echocardiographic studies, two patients with the smallest bioprosthesis (21 mm) have developed pulmonary gradients of 80 and 85 mmHg, 65 and 80 months following PVR. While our results with PVR in children have been satisfactory, this operation should be performed only in symptomatic patients with severe pulmonary regurgitation because of progressive deterioration of the available bioprosthesis.

[Pubertal development after pediatric heart transplantation]

Twenty-one children and adolescents underwent orthotopic cardiac transplantation at the Hôpital Sainte-Justine between July 1984 and June 1993. Of those patients, 16 (4 girls and 12 boys) who survived more than one year after the procedure were followed prospectively for documentation of onset and progression of puberty. The immunosuppressive therapy included cyclosporine, azathioprine and prednisone. Subjects were evaluated at 6 month intervals for the study of: pubertal development according to staging by the method of Marshall and Tanner and hormonal profile (FSH, LH, testosterone, DHEAS). Despite a stagnation of pubertal signs before surgery, puberty carried on and progressed normally postoperatively. The urinary levels of gonadotropins rose to adequate levels for age. Testosterone levels in boys were related to the progression of secondary sexual characteristics. Levels of DHEAS were drastically reduced, most likely because of the supraphysiological doses of oral glucocorticoids. Our results indicate that after pediatric heart transplantation, puberty progresses normally at adolescence.

[Aortic valve replacement in children]

From January 1970 to January 1993, 47 aortic valve replacements have been performed in children aged 166.8 +/- 50 months. The valvular pathology was congenital in 39 patients and associated cardiac anomalies were present in 31 cases. 30 children had a previous surgical procedure on the aortic outflow. Seven bioprosthesis and 40 mechanical valves have been implanted. At the time of surgery, an additional major cardiac correction has been performed on 17 occasions (Konno, Bentall, Fontan, correction of truncus arteriosus etc.). While no death occurred in the group subjected only to aortic valve replacement, 7 of the 17 patients where a major cardiac procedure was added died. During a mean follow-up of 61.2 +/- 59.1 months, 3 late deaths occurred, 2 of them non related to valvular surgery. Three reoperations have been performed, in two instances for replacing a degenerated bioprosthesis. One thromboembolic event occurred as well as one temporary episode of haemolytic anaemia. No haemorrhagic complication has been observed. While the results of isolated aortic valve replacement in children are excellent, the risk for hospital death is increased substantially when a major cardiovascular procedure is added to valve replacement, and because of rapid deterioration, the heterografts are now contra-indicated in children.

Use of acetylsalicylic acid to improve patency of subclavian to pulmonary artery Gore-Tex shunts

In order to assess the influence of acetylsalicylic acid (ASA) on function and patency of Gore-Tex shunts, angiographic features of 62 Gore-Tex shunts were assessed, 31 without and 31 with postoperative ASA. Groups were selected on the basis of similar angiographic follow-up duration. Mean follow-up was 709 days for the group without ASA and 739 days for the group with it. The average daily dose of ASA was 4.5 mg/kg/day started a mean of 6.7 days after surgery. Clinical characteristics were similar between the two groups except for age at surgery which was 581 days in the group without ASA (operated between 1983 and 1987) and 303 days in the group with (operated between 1987 and 1991), reflecting the fact that patients were operated upon earlier after 1987. Preoperative Gore-Tex diameter was similar between the two groups, but three patients in the group with ASA had a Gore-Tex shunt as small as 4 mm. At angiography, four conduits were diagnosed as nonpatient (two in each group), 20 had a localized stenosis (11 of 28 in the group without ASA and nine of 23 in the group with ASA). Patency index (angiographic Gore-Tex diameter/preoperative Gore-Tex diameter) was similar in the two groups: 68.5% in the group without ASA and 69.7% in the group with ASA. Pulmonary artery growth index was 57% in the group without ASA and 91% in the group with ASA. No risk factor for thrombosis or decreased patency was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of PGE1 in experimental vasoconstrictive pulmonary hypertension

The pulmonary vascular and systemic effects of PGE1 were studied in a canine model of pulmonary hypertension. Systemic arterial, central venous and pulmonary arterial pressures were monitored and an electromagnetic flow probe was placed around the ascending aorta for continuous cardiac index (CI) measurements. Through a laparotomy, an arteriovenous fistula was created between the abdominal aorta and inferior vena cava. Gradual opening of this fistula significantly affected CI and these values were used to generate pressure-flow curves (pulmonary arterial pressure (PAP)/CI). Following PGF2 alpha infusion (5-10 micrograms/kg/min) significant pulmonary hypertension was observed (2- to 3-fold increase in PAP). PGF2 alpha infusion also resulted in a significant rise in heart rate and systemic vascular resistance (SVR) while CI was reduced. PGF2 alpha significantly increased both the line slope (vascular resistance) and intercept (outflow pressure) of the pressure-flow curves. Intravenous PGE1 infusion in doses ranging from 40 to 320 ng/ml/min elicited a dose-dependent reduction of both pulmonary and systemic vascular resistances, the former being slightly more affected. With PGE1 infusions only the intercept of the pressure-flow curve was affected suggesting that specific components of the pulmonary vascular bed modulating the outflow pressure were involved. High doses of PGE1 significantly decreased arterial PO2, indicating that this prostaglandin derivative deteriorates pulmonary gas exchanges.

Pulmonary banding complicated by low origin of right pulmonary artery

In our attempt to band the main pulmonary artery above the valve in a 4-month-old prematurely born infant, we erroneously banded only the left pulmonary artery, owing to the unusually low origin of the right pulmonary artery (which arose partially in the sinus of Valsalva). When severe cardiac failure recurred, the anomaly was noted upon reoperation and the band was repositioned at the level of the pulmonary valve. Since this revision, the postoperative course has been good. Low origin of the right pulmonary artery is normal in premature infants. However, origin of the right pulmonary artery from the sinus of Valsalva is a sufficiently extreme variant to constitute a surgically important anomaly. Our postmortem studies of the pulmonary arteries of 25 premature infants born without cardiac malformation showed that while the right pulmonary artery was lower than the left, it never originated from the sinus of Valsalva. This anomalous configuration of the pulmonary arteries has, to our knowledge, never been found in an infant as old as 4 months; yet we believe it should be taken into account when banding pulmonary arteries in infants.

Efficacy of dobutamine in the failing transplanted heart

Acute rejection often leads to severe myocardial failure and death. Surprisingly, no systematic study on the efficacy of beta-adrenergic pharmacologic agents have been reported to the present. Because of all the pathophysiologic alterations documented during rejection, we expected an inappropriate response to inotropic drugs, so we have questioned the value of dobutamine during those circumstances. Twelve dogs underwent orthotopic transplantation and were prepared with implantable devices for serial hemodynamic studies to be performed on the resting unanesthetized subject. Of this number, six dogs were studied while they were in immediate postoperative heart failure (3 hours after operation), and the same study was performed when myocardial failure secondary to rejection occurred (5 to 7 days). After basal state measurement, 5 and 10 micrograms.kg-1.min-1 of dobutamine were infused continuously, and the hemodynamic response during the two phases was compared. The baseline cardiac index in the immediate postoperative period was 1.4 +/- 0.4 L.min-1.m2 and 1.8 +/- 1.0 L.min-1.m2 during rejection, showing a similar degree of heart failure. Dobutamine (5 micrograms.kg-1.min-1) increased cardiac index by 97% 3 hours after transplantation and by 35% during rejection (p < 0.05). With 10 micrograms.kg-1.min-1 of dobutamine, the difference between increments was not significant (99% versus 79%). Raising the infusion rate of the drug to 15 and 20 micrograms.kg-1.min-1 during rejection increased cardiac index by 97% and 118%, respectively. Interestingly, no detrimental tachycardia occurred with this increased dosage. Heart failure secondary to acute rejection can therefore be improved by dobutamine.(ABSTRACT TRUNCATED AT 250 WORDS)