Management of obstructive sleep apnea in children: a Canada-wide survey.

BACKGROUND: Obstructive sleep apnea frequently persists in children following adenotonsillectomy, which is the first-line treatment recommended for obstructive sleep apnea with adenotonsillar hypertrophy. Drug-induced sleep endoscopy (DISE) is a diagnostic tool increasingly used to assess pediatric obstructive sleep apnea, but its use has not been standardized. The overarching goal of this study was to document the current practice of Canadian otolaryngologists managing this population. METHODS: A nation-wide online cross-sectional survey of Canadian otolaryngologist members of the Canadian Society of Otolaryngology - Head and Neck Surgery and the Association d'otorhinolaryngologie et chirurgie cervico-faciale du Québec. The 58-question electronic survey was developed based on a validated survey redaction guide with the aim to assess management and treatment of pediatric obstructive sleep apnea, as well as indications and performance of DISE. Consensus on practice items was defined by a minimum of 75% similar answers. RESULTS: One hundred and nine Canadian otolaryngologists completed the survey on management of pediatric obstructive sleep apnea, among which 12 of them completed the questions on DISE. Overall, there was a poor rate of agreement of 55% among the respondents for the 58 questions altogether. There was a consensus to assess pediatric obstructive sleep apnea clinically ± with videos (82.6%), to assess adenotonsillar hypertrophy clinically (93.6%) and with flexible scope in the office (80.7%), as well as for the airway sites examined endoscopically during DISE. However, there was no consensus regarding anesthetic protocol and scoring system. DISE was mostly performed in cases of persistent obstructive sleep apnea after adenotonsillectomy rather than before performing any surgical procedure. There was no difference in the management of obstructive sleep apnea between otolaryngologists who perform DISE and those who do not. The only difference between otolaryngologists who practice in community centers versus in tertiary care centers was the more frequently use of the Brodsky tonsil scale by the latter ones. CONCLUSION: This Canadian-wide survey highlighted a lack of consensus in the management of pediatric obstructive sleep apnea and DISE. Certain aspects regarding DISE remain unclear, including establishment of its ideal timing in order to eventually avoid unnecessary tonsillectomies.

Plotting transcutaneous bilirubin measurements on specific transcutaneous nomogram results in better prediction of significant hyperbilirubinemia in healthy term and near-term newborns: a pilot study.

BACKGROUND: The American Academy of Pediatrics has recommended a systematic assessment before discharge for the risk of severe hyperbilirubinemia. Plotting total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) on a TSB hour-specific nomogram is proposed as a tool for laboratory evaluation. OBJECTIVES: The aim of this study was to compare the predictive characteristics, particularly the incidence of false negative rate (FNR), of the practice of plotting TcB values on the TSB hour-specific risk nomogram versus on transcutaneous nomogram. METHODS: Paired TSB and TcB measurements were conducted on 141 newborns. Risk of developing significant hyperbilirubinemia was defined as infants with bilirubin level ≥ 75% on TSB or ≥ 95% on TcB nomogram. TSB values, plotted on the TSB nomogram of Bhutani et al. [Pediatrics 1999;103:6-14], were used as reference. TcB values were plotted on the TSB nomogram and on the transcutaneous nomograms of Maisels and Kring [Pediatrics 2006;117:1169-1173] and Fouzas et al. [Pediatrics 2010;125:e52-e57]. RESULTS: Plotting TcB measurements on a TSB nomogram resulted in a trend towards a higher FNR when compared to Maisels' and Fouzas' nomograms (18.0/1,000 compared to 10.2/1,000 and 8.6/1,000 respectively). Although not statistically significant, plotting TcB on transcutaneous nomogram resulted in better predictive values with the Fouzas' nomogram, having the best sensitivity (90.0%) and specificity (87.79%) as well as the highest positive (35.97%) and negative (99.14%) predictive value. CONCLUSION: Plotting TcB on a TSB nomogram may result in increased rate of FNR and decreased predictive characteristics. The practice of plotting TcB on a TSB nomogram needs further evaluation.

Genomics and public health research: can the state allow access to genomic databases?

Because many diseases are multifactorial disorders, the scientific progress in genomics and genetics should be taken into consideration in public health research. In this context, genomic databases will constitute an important source of information. Consequently, it is important to identify and characterize the State's role and authority on matters related to public health, in order to verify whether it has access to such databases while engaging in public health genomic research. We first consider the evolution of the concept of public health, as well as its core functions, using a comparative approach (e.g. WHO, PAHO, CDC and the Canadian province of Quebec). Following an analysis of relevant Quebec legislation, the precautionary principle is examined as a possible avenue to justify State access to and use of genomic databases for research purposes. Finally, we consider the Influenza pandemic plans developed by WHO, Canada, and Quebec, as examples of key tools framing public health decision-making process. We observed that State powers in public health, are not, in Quebec, well adapted to the expansion of genomics research. We propose that the scope of the concept of research in public health should be clear and include the following characteristics: a commitment to the health and well-being of the population and to their determinants; the inclusion of both applied research and basic research; and, an appropriate model of governance (authorization, follow-up, consent, etc.). We also suggest that the strategic approach version of the precautionary principle could guide collective choices in these matters.

Framing genomics, public health research and policy: points to consider.

Genetic information can be used to target interventions that improve health and prevent disease. Indeed, the results of population genomics research could be useful for public health and national pandemic plans. Yet, firm scientific evidence originating from such research and the indicators of the role of health determinants, gene-gene and gene-environment interaction remain to be assessed and validated before being integrated into pandemic plans or public health programmes. It is not clear what is the role of the State in research on the elucidation of the determinants of gene-gene and gene-environment interactions and how, when, and if such data can be accessed and used for such planning. Over a period of 3 years, we sought to address these questions by gathering data and literature relevant to research in public health genomics, preparing issues papers and, finally, consulting with stakeholders on a provisional 'points to consider' document at various times. Examining in turn the issues of privacy, State powers, stakeholder perceptions, and public participation, we propose in this article, for each of these themes, a series of recommendations aiming to provide guidance on the role of the State in the use of genomic information for public health research, prevention and planning.

Point of care testing: transcutaneous bilirubinometry in neonates.

Physicians taking care of infants in the first days of life are often faced with neonatal jaundice, especially in an era where post-partum discharge occurs earlier and assessment of newborn bilirubinemia status is required prior to discharge. The Canadian Pediatric Society and the American Academy of Pediatrics have developed and published guidelines for the diagnosis and management of hyperbilirubinemia in newborns. Point of care testing refers to any test performed outside of laboratory by clinical personnel and close to the site of patient care. Based on a summary of multiple reports during the last twenty years, we realize that devices which provide a non-invasive transcutaneous bilirubin (TcB) measurement have proven to be very useful as screening tools and provide a valid estimate of the total serum bilirubin level (TSB). Published data suggest that these devices provide measurements within 30-50 micromol/L of the TSB levels and can replace laboratory measurement particularly when TSB levels are less than 260 micromol/L. At the present time, in the literature, evidence is insufficient to abandon neonatal serum bilirubin testing and replace it with TcB. Any measurement, TSB or TcB, has potential for error. However, we have evidence that TcB, can help avoiding potential errors associated with even visual assessment of jaundice and may be useful as screening device to detect significant jaundice and decrease a large number of unnecessary skin punctures. The current manuscript is based on a careful comprehensive literature review concerning neonatal hyperbilirubinemia. We consider that this manuscript will help clinicians and laboratory professionals in the management of neonatal jaundice.

[Evaluation of transcutaneous bilirubin measurement and agreement with bilirubinemia]. / Evaluation de la mesure transcutanée de la bilirubine et concordance avec la mesure sur sang total et plasma.

Evaluation of the neonates for jaundice and kernicterus is indispensable when early hospital discharge has become standard practice. Transcutaneous bilirubin (TcB) measurement is an advantageous option because of its non-invasive nature and the possibility of its use near the patient. The point of care device BiliCheck has been compared in numerous instances to serum bilirubin. However, its clinical utility remains a subject of discussion. We have compared total blood bilirubin (TBB) concentrations to TcB values using the BiliCheck in newborns at 48 +/- 12 hours of life, at the time of discharge when they have lost weight. One hundred and ninety-six term neonates were initially included into the study. Transcutaneous bilirubin could be compared to whole blood bilirubin for 178 of them. Methods were compared by linear regression analysis and by the non-parametric Bland and Altman method. The correlation between BiliCheck and whole blood bilirubin was adequate (r(2): 0.7768). However, the Bland-Altman analysis revealed a 95% CI of -50.4 to 47.5 micromol/L. Transcutaneous bilirubin was also compared to a measure on plasma in a sub-group of 53 infants, the correlation was 0.7749 with a 95% CI of -35.8 to 46.5 micromol/L. Comparing total blood bilirubin with plasma bilirubin in 35 patients, we observed a similar results with a correlation of 0.7583 and a 95% CI of -34.6 to 40.7 micromol/L. Finally, the extent of weight loss observed in our group of patients had little influence and did not affect the agreement between the 2 approaches. We conclude that the BiliCheck may be used to monitor bilirubin in term neonates at 48 hours of life even with a weight loss. Clinicians have however to be conscious of the limit of the precision of the measures both for the BiliCheck and the laboratory methods.

Natremia of healthy term newborns at 48 h of life: influence of feeding patterns.

OBJECTIVES: To describe natremia in healthy term newborns and determine whether there is a relationship between blood sodium and feeding patterns. METHODS: All normal newborns, admitted to the nursery between January and March 2004 were eligible for this prospective cohort study. Inclusion criteria were: > or =37 weeks of gestational age, birth weight > or =2500 g, Apgar scores > or =7 at 5 and 10 min and normal physical examination. A capillary blood sample was taken at 48+/-12 h of life. RESULTS: Blood samples from 126 newborns were analyzed. Mean gestational age was 39.6 weeks, birth weight was 3414 g and weight loss at 48 h of life was 6.5% of birth weight. Mean capillary blood sodium was 141 mmol/L (SD 3.4). Exclusively, breast-fed newborns had statistically higher mean blood sodium (141 mmol/L, SD 3.0) than the non-exclusively breast-fed+formula fed group (139 mmol /L, SD 3.7). There was a significant linear association between blood sodium and the quantity of milk supplements received as well as between blood sodium and weight loss. CONCLUSIONS: Most newborns have blood sodium values within a narrower range than previously described in the literature. We also demonstrate that the exclusively breast-fed infants appear to have marginally but statistically higher values of blood sodium than non-exclusively breast-fed and formula-fed infants.

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.

Fetal intestinal microvilli in human amniotic fluid.

The intestinal microvilli of fetal origin in human amniotic fluid were purified by Ca2+ precipitation of contaminating organelles followed by differential centrifugation of microvillar membranes. In the purified preparation, the specific activity of the microvillar marker-enzymes maltase and sucrase increased about 77-fold over that in cell-free amniotic fluid. Significant contamination of the purified preparation by endoplasmic reticulum (microsomes) and lysosomes was ruled out on the basis of a low content of the marker enzymes glucose-6-phosphatase (microsomes) and acid phosphatase (lysosomes). Amniotic fluid microvilli contain typical enzymes of the fetal intestine including maltase, sucrase, trehalase, alkaline phosphatase and gamma-glutamyltransferase, and their morphology by electron microscopy resembles that of vesiculated intestinal microvilli. Prenatal detection of genetic diseases due to a deficiency of a protein expressed in these membranes or associated to abnormal microvilli seems feasible.

The nerve branches to the external anal sphincter: the macroscopic supply and microscopic structure.

The study was performed using 45 pelvic half section specimens (41 fetal ones and four adults). The macroscopic dissection followed the nerve branches from their spinal roots up to the external anal sphincter. Three nerve branches were found: the anterior ramus arising from the external perineal nerve, the inferior rectal nerve and an independent posterior branch. The anterior and the inferior rectal nerve branches always emerged from the pudendal plexus. The posterior branch arising either from S4 or from the inferior rectal nerve was only found in (31%) of our cases. Five anatomical distributions are described, percentages of every type notified. The fibre content of these nerve bundle branches was evaluated through histological sections using Heidenhain's azan stain and Luxol fast blue. The branches consisted of 2,896 to 2,137 fibres, 20% of them being unmyelinated and 80% containing various myelinated fibres. The nomenclature of these nerve branches has to be debated. The terms of anterior, middle and posterior anal nerves seem more suitable.

The morphological effects in pig liver after Nd-YAG laser resection.

The morphological effects of liver resection in 15 pigs performed with a Nd-YAG laser beam are reported. A regular cut surface was obtained and overlayed an ischemic layer which was thinnest at a 80 W power output and a short exposure time. Hemostasis was satisfying when the encountered vessels did not exceed 4,5 mm in diameter. Semi-thin and electron microscopic examination showed "ghost" cells in the layer of coagulation necrosis, shrunken hepatocytes and red blood cells in oedematous layer and "swollen" mitochondria in the deepest layer. Clamping of the hepatic pedicle - increasing local hyperthermia by suppression of cooling vascular inflow - majorated the depth of cellular alterations and the intensivity of the post-operative inflammatory reaction. Numerous biliary ductules and active hepatocytes meant parenchymal regeneration. Good healing evolution free of complications was observed after a one year's follow up.

[Numbering of the dorsal spinal nerve roots in man from the 12th thoracic nerve to the coccygeal nerve]. / Numération des radicelles dorsales des nerfs spinaux chez l'homme du 12e nerf thoracique au nerf coccygien.

A bilateral study for locating the dorsal root filaments of specific nerves was accomplished from the twelfth thoracic to the coccygeal level and this using 26 fetal and 8 adult specimens. After laminectomy from the thoracic to coccygeal levels, incision of the dural sac permitted visualisation of the dorsal root filaments, the successive rootlets corresponding to each segmental level (T12 to Co1 ) were counted with the aid of a binocular microscope where they penetrated the spinal medulla at the posterior sulcus. Statistical evaluation shows that for each dorsal nerve the average number of root filaments is greater on the right compared with the left. Numbering the dorsal nerve root filaments in the cephalo -caudal direction allows to assert with 99% probability up to the L5 level and with 95% probability up to the S1 level that one is at a given spinal level of the respective segmental range; caudal-cephalic direction numbering permits to affirm with 99% probability up to the S1 level and 95% probability up to the L4 level that one is at a given spinal level of the respective segmental range.

Separation of amniotic fluid cell types in primary culture by Percoll density gradient centrifugation.

Amniotic fluid cells obtained by transabdominal amniocentesis at 15-17 weeks of gestation and cultured for 15 and 21 days were separated into three fractions by density gradient centrifugation in Percoll. Each fraction (or peak) corresponded to the following densities: peak A, 1.02-1.03 g/ml; peak B, 1.04-1.05; peak C, 1.05-1.06. Peak A was composed of both non-viable and viable cells; the latter adopted the morphology of epithelial cells in culture. Peak B contained a mixture of fibroblasts and epithelioid cells and peak C had only epithelioid cells. The variability of N-acetyl-beta-hexosaminidase and alkaline phosphatase activities was reduced in peaks B and C as compared to that of peak A and of unseparated cells suggesting that more defined and homogeneous cell types for enzymatic determinations can be obtained by centrifugation in Percoll density gradient. In prenatal diagnosis of biochemical defects, the separation of cells would permit a more precise diagnosis by eliminating enzyme variability due to the presence of different cell types or non-viable cells.

Oral lecithin and linoleic acid in Friedreich's ataxia: III. Biochemical results.

Lecithin and safflower oil brought about the same changes in serum LAD activity and kinetics in patients with Friedreich's Ataxia as in controls when results of this double-blind crossover study were analyzed according to group assignation. According to functional stages, pretrial LAD activity decreased with advancing severity while Km for lipoamide increased. Lecithin and safflower oil supplements corrected the elevated Km for lipoamide but produced a further reduction in LAD activity. These changes may have been due to the increased intake of linoleic acid, a precursor of lipoic acid, which is present in high percentage in both lecithin and safflower oil. Results of the biochemical study thus agreed with the clinical data gathered during the course of the one-year trial in suggesting that linoleic acid may well have been the active factor through which biochemical and clinical improvement was previously observed in patients with Friedreich's Ataxia supplemented with lecithin.

Isolation and characterization of the proximal and distal forms of lactase-phlorizin hydrolase from the small intestine of the suckling rat.

The complex between lactase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) and phlorizin hydrolase (glycosyl-N-acylsphingosine glycohydrolase, EC 3.2.1.62) has been purified from the proximal and distal regions of the small intestine of suckling rats. The two enzymes behaved differently on DEAE-cellulose ion-exchange chromatography and during electrophoresis in the presence and absence of sodium dodecyl sulphate (SDS), but they have very similar cyanoge bromide cleavage patterns. Kinetic studies on the proximal and distal enzymes showed the same pH optimum of 6.0 and the same heat stability at 45 degrees C, but a small difference in Km. Treatment of both enzymes with fucosidase, mannosidase or N-acetylhexosaminidase did not affect enzymic activity or electrophoretic mobility. Neuraminidase digestion abolished the electrophoretic differences and gave two active enzymes with similar isoelectric points.

[Inter-provincial labor force mobility in Canada: the case of Ontario, Nova Scotia, and New Brunswick]. / La mobilite interprovinciale de la main-d'oeuvre au Canada: le cas de l'Ontario, de la Nouvelle-Ecosse et du Nouveau-Brunswick

The author examines migration between Ontario and the two Atlantic provinces of Canada from 1960-1961 to 1975-1976. "Search theory is used as the theoretical framework and leads to predictions as to the influence on interprovincial migratory flows of three economic variables: relative wages, employment opportunities, and employment insurance." (summary in ENG)

Parasites and diseases of bison in Canada IV. Serologic survey for brucellosis in bison in northern Canada.

Serum samples collected from 2,365 free-roaming hybrid bison (Bison bison bison x Bison bison athabascae) in Wood Buffalo National Park and adjacent areas in the Northwest Territories were tested for brucellosis during the period 1959 to 1974. A positive reaction was obtained in 739 (31.2%) of the animals tested. The overall effect of brucellosis on this free-roaming bison population is unknown. The authors also dealt with some of the actual and possible consequences of the disease in this population.

Sequential chemical modification of a histidyl and a cysteinyl residue in bacterial luciferase.

Sequential modification of two amino acid residues (a histidyl and a cysteinyl residue), both essential for the enzymatic function of bacterial luciferase from Beneckea harveyi, has been conducted to determine if the inactivation arising from the chemical modification of either of these residues is due to a conformational change. This experimental approach has shown that modification of the histidyl or cysteinyl residue did not affect the reactivity of the remaining 'essential' residue, suggesting that chemical modification had not caused a change in conformation. Furthermore, since substrates protect luciferase against inactivation due to modification of either of these residues, it was possible to determine if the initial modification of the histidyl or cysteinyl residue prevented substrate binding by conducting the modification of the remaining residue (i.e., the cysteinyl or histidyl residue, respectively) in the presence of substrates. The results have shown that after modification of the histidyl residue substrates no longer protected the cysteinyl residue against modification, whereas after modification of the cysteinyl residue substrates still protected the histidyl residue against modification. These results have provided evidence that the histidyl residue and not the cysteinyl residue of luciferase is essential for the binding of substrates in the bacterial bioluminescent reaction.