Montreal Children's Hospital

About: Montreal Children's Hospital is a healthcare organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 3842 authors who have published 4816 publications receiving 200198 citations.

Reproducibility of electroretinograms recorded with DTL electrodes

Abstract: The purpose of this study was to examine whether the use of the DTL fiber electrode yields stable and reproducible electroretinographic recordings. To do so, luminance response function, derived from dark-adapted electroretinograms, was obtained from both eyes of 10 normal subjects at two recording sessions spaced by 7–14 days. The data thus generated was used to calculate Naka-RushtonVmax andk parameters and values obtained at the two recording sessions were compared. Our results showed that there was no significant difference in the values ofVmax andk calculated from the data generated at the two recording sessions. The above clearly demonstrate that the use of the DTL fiber electrode does not jeopardize, in any way, the stability and reproducibility of ERG responses.

Reliability in the ratings of quality of life between parents and their children of school age with cerebral palsy

Abstract: Quality of life is recognized as an important outcome of health services. Ideally, the child’s perspectives should be sought directly to define their quality of life; however, this may be limited by age and cognitive and language abilities. In a sample of school-aged children with cerebral palsy (CP), we compared a parent’s perspective of their child’s quality of life with their child’s own perspective, when feasible. Forty-eight children completed the Pediatric Quality of Life Inventory (PedsQL) measure independently (n = 33/48, 69% Gross Motor Function Classification System (GMFCS) I; n = 6/48, 12% III–V). A parent completed the proxy version and the scores were compared. Intraclass correlation (ICC) coefficients were high for physical (ICC = 0.72, confidence interval [CI]: 0.55–0.83) and moderate for psychosocial (ICC = 0.54, CI: 0.30–0.71) well-being, with the weakest agreement on school functioning and the strongest agreement for ratings of physical health. Parental ratings were more often lower, especially for social functioning, although children rated themselves lower on emotional functioning. Factors associated with a closer agreement between parent–child pairs included older age, male gender, higher social competency, functional abilities, and fewer emotional symptoms (r 2 = 0.07–0.30). In children with CP, parents’ ratings of their children’s quality of life are generally comparable as a group to their child’s self-report. Disparities do exist, particularly in psychosocial domains, and, therefore, the child’s own perspective should be considered whenever feasible.

Supratentorial primitive neuroectodermal tumors: a Canadian pediatric brain tumor consortium report.

Abstract: Introduction Supratentorial primitive neuroectodermal tumors (SPNET) are rare tumors accounting for only 2.5% of childhood brain tumors. The purpose of this study was to describe the range of treatment regimens used to treat pediatric SPNET in Canada and to identify prognostic factors for overall survival in this population. Methods This study was a retrospective clinical analysis of SPNET patients treated over the last 10 years in Canada. A questionnaire was developed and distributed to all institutions in Canada who treat pediatric patients. Data were collected for patients 2 years. Overall survival was not affected by metastatic disease at diagnosis, tumor site, or degree of initial resection. Conclusions Survival is poor in SPNET patients but highest in those who received chemotherapy and radiation therapy. Further studies are needed to improve the survival of these patients.

Extracellular Vesicles in Brain Tumor Progression

Abstract: Brain tumors can be viewed as multicellular 'ecosystems' with increasingly recognized cellular complexity and systemic impact. While the emerging diversity of malignant disease entities affecting brain tissues is often described in reference to their signature alterations within the cellular genome and epigenome, arguably these cell-intrinsic changes can be regarded as hardwired adaptations to a variety of cell-extrinsic microenvironmental circumstances. Conversely, oncogenic events influence the microenvironment through their impact on the cellular secretome, including emission of membranous structures known as extracellular vesicles (EVs). EVs serve as unique carriers of bioactive lipids, secretable and non-secretable proteins, mRNA, non-coding RNA, and DNA and constitute pathway(s) of extracellular exit of molecules into the intercellular space, biofluids, and blood. EVs are also highly heterogeneous as reflected in their nomenclature (exosomes, microvesicles, microparticles) attempting to capture their diverse origin, as well as structural, molecular, and functional properties. While EVs may act as a mechanism of molecular expulsion, their non-random uptake by heterologous cellular recipients defines their unique roles in the intercellular communication, horizontal molecular transfer, and biological activity. In the central nervous system, EVs have been implicated as mediators of homeostasis and repair, while in cancer they may act as regulators of cell growth, clonogenicity, angiogenesis, thrombosis, and reciprocal tumor-stromal interactions. EVs produced by specific brain tumor cell types may contain the corresponding oncogenic drivers, such as epidermal growth factor receptor variant III (EGFRvIII) in glioblastoma (and hence are often referred to as 'oncosomes'). Through this mechanism, mutant oncoproteins and nucleic acids may be transferred horizontally between cellular populations altering their individual and collective phenotypes. Oncogenic pathways also impact the emission rates, types, cargo, and biogenesis of EVs, as reflected by preliminary analyses pointing to differences in profiles of EV-regulating genes (vesiculome) between molecular subtypes of glioblastoma, and in other brain tumors. Molecular regulators of vesiculation can also act as oncogenes. These intimate connections suggest the context-specific roles of different EV subsets in the progression of specific brain tumors. Advanced efforts are underway to capture these events through the use of EVs circulating in biofluids as biomarker reservoirs and to guide diagnostic and therapeutic decisions.

Lessons learned from the data analysis of the second harvest (1998-2001) of the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database.

Abstract: Objective: The analysis of the second harvest of the STS Congenital Heart Surgery Database produced meaningful outcome data and several critical lessons relevant to congenital heart surgery outcomes analysis worldwide. Methods: This data harvest represents the first STS multi-institutional experience with software utilizing the nomenclature and database requirements adopted by the STS and EACTS (April 2000 Annals of Thoracic Surgery). Members of the STS Congenital Heart Committee analyzed the STS data. Results: This STS harvest includes data from 16 centers (12787 cases, 2881 neonates, 4124 infants). In 2002, the EACTS reported similar outcome data utilizing the same database definitions (41 centers, 12736 cases, 2245 neonates, 4195 infants). Lessons from the analysis include: (1) Death must be clearly defined. (2) The Primary Procedure in a given operation must be documented. (3) Inclusionary and exclusionary criteria for all diagnoses and procedures must be agreed upon. (4) Missing data values remain an issue for the database. (5) Generic terms in the nomenclature lists, that is terms ending in Not Otherwise Specified (NOS), are redundant and decrease the clarity of data analysis. (6) Methodology needs to be developed and implemented to assure and verify data completeness and data accuracy. 'Operative Mortality' and 'Mortality Assigned to this Operation' were defined by the STS and EACTS; these definitions were not utilized uniformly. 'Thirty Day Mortality' was problematic because some centers did not track mortality after hospital discharge. Only 'Mortality Prior to Discharge' was consistently reported. Designation of Primary Procedure for a given operation determines its location for analysis. Until Complexity Scores lead to automated methodology for choosing the Primary Procedure, the surgeon must designate the Primary Procedure. Inclusionary and exclusionary criteria for all diagnoses and procedures have been developed in an effort to define acceptable concomitant diagnoses and procedures for each analysis. Improvements in data completeness can be achieved using a variety of techniques including developing more functional techniques of data entry at individual institutions and software improvements. Future versions of the STS Congenital Database will request that the coding of diagnoses and procedures avoid the terms ending in NOS. Conclusions: Lessons from this data harvest should improve congenital heart surgery outcome analysis.